Charging device for electrophotography
AssigneeToshiba Tec Kabushiki Kaisha
InventorKazuhisa Takeda
Life of this patent
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Abstract
A charging device for electrophotography includes a charging brush, having many fibers extending in radial around a rotation shaft and contacted with a surface of a photosensitive drum, for rotating to electrically charge the surface of the photosensitive drum with the fibers, and a charging control member located on a downstream side of a contact between the charging brush and the photosensitive drum in a rotation direction of the charging brush for temporarily retarding a movement of the fibers of the charging brush to increase an effective density of the fibers to be contacted with the surface of the photosensitive drum. Particularly, an end of the charging control member is at a distance of at least 1 mm from the contact between the charging brush and the photosensitive drum.
Claims17
A charging device for electrophotography, comprising:
- a rotary charging member having a plurality of fibers radially extending about a rotation shaft, the rotary charging member rotating about the rotation shaft such that the plurality of fibers contact a surface of a photosensitive image carrier to electrically charge the surface of said photosensitive image carrier;
- and
- a charging control member located on a downstream side of a contact between said rotary charging member and said photosensitive image carrier in a rotation direction of said rotary charging member for temporarily retarding a movement of the fibers of said rotary charging member;
- wherein said charging control member includes a first control plate which is inclined and extends toward said contact and has an end whose position is separated by at least 1 mm from said contact and determined such that intervals of said fibers are narrowed to increase an effective density of said fibers near the surface of said photosensitive image carrier.
An electrophotographic apparatus comprising:
- a charging section for electrically charging a photosensitive image carrier;
- an exposing section for selectively exposing the photosensitive image carrier to form an electrostatic latent image;
- a developing section for developing the electrostatic latent image on said photosensitive image carrier as a toner image;
- and
- a transfer section for transferring the toner image from the photosensitive image to a recording sheet;
- wherein said charging section includes:
- a rotary charging member, having a plurality of fibers radially extending about a rotation shaft, the rotary charging member rotating about the rotation shaft such that the plurality of fibers contact a surface of said photosensitive image carrier to electrically charge the surface of said photosensitive image carrier;
- and
- a charging control member located on a downstream side of a contact between said rotary charging member and said photosensitive image carrier in a rotation direction of said rotary charging member for temporarily retarding a movement of the fibers of said rotary charging member;
- wherein said charging control member includes a first control plate which is inclined and extends toward said contact and has an end whose position is separated by at least 1 mm from said contact and determined such that intervals of said fibers are narrowed to increase an effective density of said fibers near the surface of said photosensitive image carrier.
A process unit adapted to be detachably mounted on an electrophotographic apparatus, comprising:
- a photosensitive image carrier;
- and
- a charging section for electrically charging a photosensitive image carrier;
- wherein said charging section includes:
- a rotary charging member, having a plurality of fibers radially extending about a rotation shaft, the rotary charging member rotating about the rotation shaft such that the plurality of fibers contact a surface of said photosensitive image carrier to electrically charge the surface of said photosensitive image carrier;
- and
- a charging control member located on a downstream side of a contact between said rotary charging member and said photosensitive image carrier in a rotation direction of said rotary charging member for temporarily retarding a movement of the fibers of said rotary charging member
- wherein said charging control member includes a first control plate which is inclined and extends toward said contact and has an end whose position is separated by at least 1 mm from said contact and determined such that intervals of said fibers are narrowed to increase an effective density of said fibers near the surface of said Photosensitive image carrier.
Dependencies are inferred from the claim text.