Developing device
First Claim
1. A developing device comprising a first screw and a second screw to convey developer in axial direction, whereinas to at least one of the first screw and the second screw, conveying force of developer is different at the upstream side and downstream side in conveying direction so that the depth of developer within the screw becomes uniform irrespective of the position in the axial direction.
1 Assignment
0 Petitions
Accused Products
Abstract
A supply screw 10 and a collection screw 20 for a developing device equip with screw blades having different forms at particular sections so as to make conveying force of developer different depending on sections. Screw blades for big conveying force are attached within sections where developer distribution is dense while screw blades for small conveying force are attached within sections where developer distribution is sparse. In other words, conveying force is made to be greater at sparse-distribution section while smaller at dense-distribution section. Developer delivery is also promoted by providing different conveying force area within carry-up area where developer is carried up from a supply screw 10 to a collection screw 20 or vice versa. By making conveying force of each section different, developer is uniformly delivered to a developing roll 87 whether in width direction or in axial direction. Furthermore, developer circulation in a developing device becomes smooth.
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Citations
38 Claims
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1. A developing device comprising a first screw and a second screw to convey developer in axial direction, wherein
as to at least one of the first screw and the second screw, conveying force of developer is different at the upstream side and downstream side in conveying direction so that the depth of developer within the screw becomes uniform irrespective of the position in the axial direction.
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14. A developing device comprising a first conveying means and a second conveying means, wherein
conveying force by receiving side'"'"'s conveying means is made to be bigger than conveying force by giving side'"'"'s conveying means at delivery area where developer is delivered between said first conveying means and said second conveying means.
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27. A developing device comprising:
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a developing roll; a supply screw which conveys developer in axial direction to supply said developer for said developing roll; a collection screw which collects developer left on said developing roll and conveys said developer in axial direction; and an agitating screw which agitates developer and conveys said developer in axial direction;
whereinsaid collection screw is arranged below said supply screw and said agitating screw is arranged above said supply screw, conveying force by upper screw is made to be larger than conveying force by lower screw within at least one of first carry-up area and second carry-up area, said first carry-up area where developer is carried up to said supply screw from said collection screw, said second carry-up area where developer is carried up to said agitating screw from said supply screw, and said first carry-up area is arranged at far more downstream side for said collection screw'"'"'s conveying direction than at said second carry up area.
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28. A developing device comprising:
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a first screw and a second screw to convey developer in axial direction; and delivery area where developer is delivered to said second screw from said first screw or vice versa, wherein larger diameter screw blade part is applied to said delivery area for at least one of said first screw and said second screw. - View Dependent Claims (29, 30)
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31. A developing device comprising:
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a developer storage tank; and a first screw and a second screw both arranged inside of said developer storage tank to convey developer;
whereindelivery area where developer is delivered from said second screw to said first screw or vice versa is arranged at downstream for conveying direction of giving side'"'"'s screw, and inner surface of said developer storage tank is curved surface at said delivery area. - View Dependent Claims (32)
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33. A developing device comprising:
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a developer storage tank; and a first screw and a second screw both arranged inside of said developer storage tank to convey developer;
whereindelivery area where developer is delivered from said first screw to said second screw or vice versa is arranged at downstream of conveying direction for giving side'"'"'s screw, and inner surface of said developer storage tank is tapered surface at said delivery area. - View Dependent Claims (34)
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35. A developing device comprising:
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a developer storage tank; and a first screw and a second screw both arranged inside of said developer storage tank to convey developer;
whereindelivery area where developer is delivered from said first screw to said second screw or vice versa is applied at downstream of conveying direction for giving side'"'"'s screw, and conveying force by said giving side'"'"'s screw is made to be smaller at said delivery area than other area. - View Dependent Claims (36, 37, 38)
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Specification