Developing roll, developing device using the same and electrophotographic apparatus
AssigneeHitachi Koki Co., Ltd.
InventorHisao Okada
Life of this patent
Estimating the term…
Abstract
In a developing roll, grooves of a length direction of a developing roll are formed on a surface of the developing roll on conditions that a ratio of a groove depth to a groove width is set to one or more and a ratio of a groove pitch to a groove width is set to two or more and a groove depth is set to three times or more a carrier particle size, and a magnetic pole of the inside of the developing roll is provided in a position of a doctor blade for regulating the amount of carriage of a developer roll, and further a magnetic force on the surface of the developing roll of the position of the doctor blade is set to 0.06 T or less.
Claims3
A developing roll that carries a two-component developer containing toner and a carrier, comprising:
- a plurality of magnetic poles disposed inside said developing roll,
- wherein grooves are formed on a surface of said developing roll along a lengthwise direction of said developing roll so that a ratio of a groove depth to a groove width is more than 1, a ratio of a groove pitch to the groove width is 2 or more, and the groove depth is three times or more of a carrier particle size, and
- wherein a development gap is 0.4 to 0.8 mm.
A developing device comprising:
- a developing roll that carries a two-component developer containing toner and a carrier, said developing roll comprising a plurality of magnetic poles disposed inside said developing roll, and wherein grooves are formed on a surface of said developing roll along a lengthwise direction of said developing roll so that a ratio of a groove depth to a groove width is more than 1, a ratio of a groove pitch to the groove width is 2 or more, and the groove depth is three times or more of a carrier particle size;
- and
- a doctor blade disposed opposite to one of said magnetic poles for regulating the amount of two-component developer carried by said developing roll,
- wherein a magnetic force on the developing roll surface of said developing roll that is opposite to said doctor blade is set to 0.06 T or less, and
- wherein a development gap is 0.4 to 0.8 mm.
An electrophotographic apparatus that forms a toner image on a photosensitive body, said electrophotographic apparatus comprising:
- a developing roll that carries a two-component developer containing toner and a carrier, said developing roll comprising a plurality of magnetic poles disposed inside said developing roll, and wherein grooves are formed on a surface of said developing roll along a lengthwise direction of said developing roll so that a ratio of a groove depth to a groove width is more than 1, a ratio of a groove pitch to the groove width is 2 or more, and the groove depth is three times or more of a carrier particle size;
- and
- wherein a magnetic force on the developing roll surface of said developing roll that is opposite to a doctor blade is set to 0.06 T or less, and
- wherein a development gap is 0.4 to 0.8 mm.
Dependencies are inferred from the claim text.