US4314017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer without carrier powder having an improved triboelectric charging property
Assignee: Canon Inc
•
Filing: 1979-01-19
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Granted: 1982-02-02
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Expires: 1999-01-19
Abstract
Abstract A developer is composed of colored insulating particles for developing an electrostatic image wherein at least the external surface of each particle comprises two different areas of which one area constitutes a major portion of said external surface and comprises an element which defines the polarity of the triboelectric charge of said particle to a determined polarity while the other area comprises an element capable of being easily separated from said particle, transferred to a surface of a developing device and charged to a polarity opposite to that of said particle.
Inventors
- 👤 Tohru Takahashi
- 👤 Tsutomu Toyono
- 👤 Junichiro Kanbe
- 👤 Shunji Nakamura
- 👤 Yasuyuki Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:28
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0825
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
114 words
A developer without carrier powder and composed of colored insulating particles for developing an electrostatic image, wherein at least the external surface of each particle comprises two different areas of which one area constitutes a major portion of said external surface and comprises an element defining the polarity of the triboelectric charge of said particle to a determined polarity while the other area comprises an element capable of being easily separated from said particle, transferred to a surface of a developing device and charged in a polarity opposite to that of said particle, wherein the surface area ratio of said one area to said other area is within a range of 5:1 to 500:1.
Claim 2
Dependent Claim
114 words
A developer without carrier powder and composed of colored insulating particles for developing an electrostatic image, wherein at least the external surface of each particle comprises two different areas of which one area constitutes a major portion of said external surface and comprises an element defining the polarity of the triboelectric charge of said particle to a determined polarity while the other area comprises an element capable of being easily separated from said particle, transferred to a surface of a developing device and charged in a polarity opposite to that of said particle, wherein the surface area ratio of said one area to said other area is within a range of 5:1 to 500:1.
Claim 3
Dependent Claim
54 words
A developer according to claim 1, wherein said element for defining the polarity of triboelectric charge and said element capable of being charged in the opposite polarity are positioned mutually well apart in the triboelectric series, that is, when said elements are rubbed together, one is positively charged while the other is negatively charged.
Claim 4
Dependent Claim
45 words
A developer according to claim 1, wherein said element for defining the polarity of triboelectric charge and said element capable of being charged in the opposite polarity are positioned in the triboelectric series on the opposite sides of a material used for the developing apparatus.
Claim 5
Dependent Claim
45 words
A developer according to claim 1, wherein the material constituting the area comprising the element defining the polarity of the triboelectric charge and the material constituting the area comprising the element capable of being charged in the opposite polarity are of a low mutual solubility.
Claim 6
Dependent Claim
31 words
A developer according to claim 1, wherein the area comprising the element capable of being charged in the opposite polarity comprises a charge control material included in an easily transferable material.
Claim 7
Dependent Claim
15 words
A developer according to claim 5, wherein said easily transferable material is a soft resin.
Claim 8
Dependent Claim
14 words
A developer according to claim 5, wherein said easily transferable material is a wax.
Claim 9
Dependent Claim
27 words
A developer according to claim 1, wherein the element capable of being charged in the opposite polarity is adhered on the surface the of colored insulating particles.
Claim 10
Dependent Claim
27 words
A developer according to claim 1, wherein the element capable of being charged in the opposite polarity is dispersed throughout the interior of the colored insulating particles.
Claim 11
Dependent Claim
21 words
A developer according to claim 1, wherein said element for defining the polarity of the triboelectric charge is a binder resin.
Claim 12
Dependent Claim
17 words
A developer according to claim 1, wherein said insulating particles comprise a soft material for pressure fixation.
Claim 13
Dependent Claim
14 words
A developer according to claim 1, wherein said insulating particles comprise a magnetic material.
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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) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |