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US 5,671,468 AGranted
Charging member and image forming apparatus having contact charging member
AssigneeCanon Kabushiki Kaisha
InventorsTakeo Yamamoto, Tetsuya Kuribayashi, Takao Honda, Fumihiro Arahira, Hiroyuki Osada
Life of this patent
Estimating the term…
Abstract
A charging device includes a movable member to be charged; a charging member contactable to the member to be charged to electrically charge the member to be charged; a discharging device, disposed upstream of a contact portion between the charging member and the member to be charged with respect to a movement direction of the member to be charged, for electrically discharging the member to be charged at a portion adjacent to the contact portion.
Claims34
An image forming apparatus comprising:
- a movable image bearing member, said image bearing member including a photosensitive layer;
- a charging member contactable to said image bearing member to electrically charge said image bearing member, wherein said charging member effects electric discharge at a downstream-side gap which is formed between said image bearing member and said charging member at a downstream-side of a nip formed therebetween;
- and
- exposure means for exposing said image bearing member, said exposure means exposing to light an area of said image bearing member corresponding to an upstream-side gap formed between said image bearing member and said charging member at an upstream-side of said nip, wherein the upstream-side gap reduces gradually from an upstream position of said nip with respect to a movement direction of said image bearing member toward said nip.
1 more element
A charging device for charging a movable member to be charged, comprising:
- a movable member to be charged;
- a charging member contactable to said member to be charged to electrically charge the member to be charged, said charging member being a rotatable member, wherein said charging member effects electric discharge at a downstream-side gap which is formed between said member to be charged and said charging member at a downstream-side of a nip formed therebetween;
- and
- discharge suppressing means for suppressing electric discharge between the member to be charged and said charging member, at an upstream-side gap formed on an upstream-side of said nip, wherein the upstream-side gap reduces gradually from an upstream position of said nip with respect to a movement direction of the member to be charged toward said nip.
1 more element
An image forming apparatus comprising:
- a movable image bearing member;
- a charging member contactable to said image bearing member to electrically charge said image bearing member, said charging member being a rotatable member, wherein said charging member effects electric discharge at a downstream-side gap which is formed between said image bearing member and said charging member at a downstream-side of a nip formed therebetween;
- and
- discharge suppressing means for suppressing electric discharge between said image bearing member and said charging member at an upstream-side gap formed on an upstream-side of said nip, wherein the upstream-side gap reduces gradually from an upstream position of said nip with respect to a movement direction of said image bearing member toward said nip.
1 more element
An image forming apparatus comprising:
- a movable image bearing member, said image bearing member including a photosensitive layer;
- a charging member contactable to said image bearing member to electrically charge said image bearing member, wherein said charging member effects electric discharge at a downstream-side gap which is formed between said image bearing member and said charging member at a downstream-side of a nip formed therebetween;
- and
- illuminating means for illuminating a boundary between a first portion where said charging member is in contact with said image bearing member, and a second portion of said image bearing member, adjacent to the first portion and upstream of the first portion with respect to a movement direction of said image bearing member, where said charging member is out of contact with said image bearing member.
1 more element
Dependencies are inferred from the claim text.