US4626487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate developer containing inorganic scraper particles and image forming method using the same
Assignee: Canon Inc
•
Filing: 1984-07-25
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Granted: 1986-12-02
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Expires: 2004-07-25
Abstract
Abstract A developer comprising colored resinous particles and inorganic fine particles having a BET specific surface area of 0.2 to 30 m 2 /g as measured by nitrogen adsorption. The inorganic fine particles have an action of promoting removal of paper powder and other adherents during cleaning of the latent image-bearing member without sticking onto the latent image-bearing member. Accordingly, the developer containing the inorganic fine particles can give good images even after successive copying operation for a long term.
Inventors
- 👤 Yasuo Mitsuhashi
- 👤 Masaki Uchiyama
- 👤 Kazunori Murakawa
- 👤 Kenji Okado
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:41
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; G03G9/00; G03G9/08; G03G9/097; G03G9/09708
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
103 words
A particulate developer, which comprises (i) 85 to 99.77% by weight of colored resinous particles, (ii) 0.2 to 10% by weight of inorganic fine particles (A) having a BET specific surface area of 0.2 to 30.0 m 2/ g as measured by nitrogen absorption, and (iii) 0.03 to 5% by weight of inorganic fine particles (B) having a BET specific surface area of 40 to 400 m 2/ g as measured by nitrogen absorption, in which each weight of said particles is based on the total weight of said colored resinous particles, said inorganic fine particles (A), and said inorganic fine particles (B).
Claim 2
Dependent Claim
103 words
A particulate developer, which comprises (i) 85 to 99.77% by weight of colored resinous particles, (ii) 0.2 to 10% by weight of inorganic fine particles (A) having a BET specific surface area of 0.2 to 30.0 m 2/ g as measured by nitrogen absorption, and (iii) 0.03 to 5% by weight of inorganic fine particles (B) having a BET specific surface area of 40 to 400 m 2/ g as measured by nitrogen absorption, in which each weight of said particles is based on the total weight of said colored resinous particles, said inorganic fine particles (A), and said inorganic fine particles (B).
Claim 3
Dependent Claim
15 words
A particulate developer according to claim 1, wherein the colored resinous particles contain magnetic particles.
Claim 4
Dependent Claim
20 words
A particulate developer according to claim 1, wherein the inorganic fine particles (A) have a Mohs hardness greater than 1.
Claim 5
Dependent Claim
18 words
A particulate developer according to claim 3, wherein the inorganic fine particles (A) have been obtained through sintering.
Claim 6
Dependent Claim
18 words
A particulate developer according to claim 4, wherein the inorganic fine particles (A) have been crushed after sintering.
Claim 7
Dependent Claim
19 words
A particulate developer according to claim 1, wherein the inorganic fine particles (A) are strontium titanate or cerium oxide.
Claim 8
Dependent Claim
16 words
A particulate developer according to claim 1, wherein the inorganic fine particles (B) are siliceous powder.
Claim 9
Dependent Claim
141 words
An image forming method, which comprises developing a latent image on a latent image bearing member with a particulate developer, transferring the developed image formed to a transfer material and removing the residual developer on the latent image-bearing member, wherein said particulate developer comprises (i) 85 to 99.77% by weight of colored resinous particles, (ii) 0.2 to 10% by weight of inorganic fine particles (A) having a BET specific surface area of 0.2 to 30 m 2/ g as measured by nitrogen absorption, and (iii) 0.03 to 5% by weight of inorganic fine particles (B) having a BET specific surface area of 40 to 400 m 2/ g as by nitrogen absorption, in which each weight of said particles is based on the total weight of said colored resinous particles, said inorganic fine particles (A), and said inorganic fine particles (B).
Claim 10
Dependent Claim
141 words
An image forming method, which comprises developing a latent image on a latent image bearing member with a particulate developer, transferring the developed image formed to a transfer material and removing the residual developer on the latent image-bearing member, wherein said particulate developer comprises (i) 85 to 99.77% by weight of colored resinous particles, (ii) 0.2 to 10% by weight of inorganic fine particles (A) having a BET specific surface area of 0.2 to 30 m 2/ g as measured by nitrogen absorption, and (iii) 0.03 to 5% by weight of inorganic fine particles (B) having a BET specific surface area of 40 to 400 m 2/ g as by nitrogen absorption, in which each weight of said particles is based on the total weight of said colored resinous particles, said inorganic fine particles (A), and said inorganic fine particles (B).
Claim 11
Dependent Claim
21 words
An image forming method according to claim 8, wherein the inorganic fine particles (A) have a Mohs hardness greater than 1.
Claim 12
Dependent Claim
19 words
An image forming method according to claim 9, wherein the inorganic fine particles (A) have been obtained through sintering.
Claim 13
Dependent Claim
18 words
An image forming method according to claim 8 wherein said latent image-bearing member comprises an organic photoconductive material.
Claim 14
Dependent Claim
19 words
An image forming method according to claim 8, wherein said latent image-bearing member is an amorphous silicon photosensitive member.
Claim 15
Dependent Claim
25 words
An image forming method according to claim 8, wherein the residual developer on the latent image-bearing member is removed by scraping with a cleaning blade.
Claim 16
Dependent Claim
25 words
A particulate developer according to claim 1, wherein the inorganic fine particles (A) comprise strontium titanate and the inorganic fine particles (B) comprise colloidal silica.
Claim 17
Dependent Claim
25 words
A particulate developer according to claim 1, wherein the inorganic fine particles (A) comprise cerium oxide and the inorganic fine particles (B) comprise colloidal silica.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |