Developing apparatus
AssigneeCanon Kabushiki Kaisha
InventorsTomoyuki Sakamaki, Mitsuhiro Furukawa
Life of this patent
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Abstract
A developing apparatus for developing a latent image formed on an image bearing member includes a developer carrying member configured to carry a developer including toner and magnetic carrier and including a developer carrying surface having a plurality of grooves, a magnet, provided inside the developer carrying member, configured to attract the developer on the developing carrying surface, and a regulating member, provided spaced from the developer carrying member and configured to regulate an amount of the developer carried on the developer carrying surface.
Claims8
(canceled)
A developing apparatus comprising:
- a developer carrying member for carrying a developer including toner and magnetic carrier to develop a latent image formed on an image bearing member, said developer carrying member including a developer carrying surface having a plurality of depressions;
- wherein said depressions are elongated in a direction perpendicular to a circumferential direction of said developer carrying member;
- and
- wherein depths D (mm) of said depressions, widths W (mm) of said depressions measured along a direction perpendicular to an elongation direction of said depressions, and a volume average particle diameter of the magnetic carrier D50 (mm) satisfy,
- D
-
- (
- mm
- )
- >
- D
- 50
-
- (
- mm
- )
- ×
- 1
- /
- 2
- ,
- and
- W
-
- (
- mm
- )
- >
- D
- 50
-
- (
- mm
- )
- ,
- a magnet, provided inside said developer carrying member, for attracting the developer on said developing carrying surface;
- and
- a regulating member, provided spaced from said developer carrying surface, for regulating an amount of the developer carried on said developer carrying surface,
- wherein the depression has a shape that becomes deeper toward the center in a cross-section orthogonal to the axial direction of the developer carrying member, and
- wherein an amount M/S (mg/mm2) of the developer carried on a unit area of said developer carrying surface after passing by said regulating member, a gap SB (mm) between a free end of said regulating member and said developer carrying member, a density G (mg/mm3) of the developer, and a ratio α which is a ratio of a portion of said developer carrying surface occupied by said depressions, relative to an entirety of said developer carrying surface satisfy,
- M
- /
- S
-
- (
- mg
- /
- mm
- 2
- )
- ×
- 1
- /
- 4
- ≤
- α
- ×
- {
- SB
-
- (
- mm
- )
- +
- D
-
- (
- mm
- )
- }
- ×
- G
-
- (
- mg
- /
- mm
- 3
- )
- <
- M
- /
- S
-
- (
- mg
- /
- mm
- 2
- )
- .
- wherein
- 0.2
- ≤
- SB
-
- (
- mm
- )
- ,
- 0.1
- ≤
- M
- /
- S
-
- (
- mg
- /
- mm
- 2
- )
- ≤
- 0.5
- ,
- and
- 0.08
- <
- α
- .
Dependencies are inferred from the claim text.