IP Library Granted Patent US 8,182,972
Granted Patent B2
US 8,182,972 · App. 12/318,325 · Granted May 22, 2012

Developer, developer storage unit, developing device, and image forming apparatus

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,182,972
App. No.
12/318,325
Granted
May 22, 2012
Kind
B2
Abstract

Developer includes toner formed of base particles containing at least a binder resin. The base particles have surfaces coated with an additive agent, and the toner has a volume average particle size between 3.9 μm and 6.1 μm. The developer further includes agglomerates in an amount between 0.01 wt % and 0.10 wt %. The agglomerates have a volume average particle size between 75 μm and 100 μm.

Claims (18)

1. Developer comprising:

toner formed of base particles each containing at least a binder resin, said base particles each having a surface coated with an additive agent, said toner having a volume average particle size between 3.9 μm and 6.1 μm inclusive; and

agglomerates having respective particle sizes between 75 μm and 100 μm inclusive, said agglomerates being in an amount between 0.01 wt% and 0.10 wt% inclusive relative to a total weight of the developer.

2. The developer according to claim 1 , wherein said toner has the volume average particle size between 3.9 μm and 5.0 μm inclusive.

3. The developer according to claim 1 , wherein said agglomerates have a size so that the agglomerates pass through a screen having an opening size of 100 μm and do not pass through a screen having an opening size of 75 μm.

4. The developer according to claim 1 , wherein said agglomerates are formed of the additive agent in an agglomerated form.

5. The developer according to claim 1 , wherein said toner and said agglomerates are mixed so that a mixture has a degree of agglomeration between 40.3% and 69.1% inclusive.

6. A developer storage unit retaining the developer according to claim 1 .

7. A developing device comprising:

developer formed of toner and agglomerates each having respective particle sizes between 75 μm and 100 μm inclusive, said toner including base particles containing at least a binder resin, said base particles each having a surface coated with an additive agent, said toner having a volume average particle size between 3.9 μm and 6.1 μm inclusive, said agglomerates being included in an amount between 0.01 wt % and 0.10 wt % inclusive relative to a total weight of the developer;

a developer supporting member for supporting the developer; and

a developer layer forming member for forming a developer layer on the developer supporting member.

8. The developing device according to claim 7 , wherein said developer layer forming member is configured to form the developer layer on the developer supporting member in a range between 0.30 mg/cm 2 and 0.58 mg/cm 2 inclusive.

9. The developing device according to claim 7 , wherein said developer layer forming member is configured to form the developer layer on the developer supporting member in a range between 0.30 mg/cm 2 and 0.52 mg/cm 2 inclusive.

10. An image forming apparatus comprising the developing device according to claim 7 .

11. A developer storage unit retaining the developer according to claims 2 .

12. The developing device according to claim 7 , wherein said toner has the volume average particle size between 3.9 μm and 5.0 μm inclusive

13. An image farming apparatus comprising the developing device according to claim 12 .

Assignments (2)
MERGER Recorded Mar 14, 2022
From: OKI DATA CORPORATION
To: OKI ELECTRIC INDUSTRY CO., LTD.
Reel/Frame 059365/0145 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 24, 2008
From: KOIDO, KENJI
To: OKI DATA CORPORATION
Reel/Frame 022094/0325 →