US5481349A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic image fixing device avoiding offset in the image by means of differential roller speed
Assignee: Ricoh Printing Systems Ltd
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Filing: 1993-12-10
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Granted: 1996-01-02
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Expires: 2013-12-10
Abstract
Abstract An electrophotographic image fixing device having preventing offsetting and affording images of high quality is provided. The electrophotographic image fixing device has a heating roller 1, made up of a mandrel 5 and an elastic layer 4 of 40-60 DEG in hardness, as measured by a spring type hardness meter of JIS K6301, provided on the mandrel, and a pressure roller 2, arranged in contact with the heating roller 1 and having a surface layer 6 the hardness of which is equal to or higher than the hardness of the elastic layer 4 of the heating roller 1. A heater 8 is provided for heating and fusion-depositing a toner image onto a toner substrate 3, by passing through the nip portion between the two rollers the toner substrate 3 on which the toner image has been formed. The linear speed of the surface of the pressure roller is 1.005-1.05 times that of the surface of the heating roller.
Inventors
- 👤 Toshiya Satoh
- 👤 Akiko Oikawa
- 👤 Katsuyoshi Onose
- 👤 Keijiro Yagi
- 👤 Tomoji Kitagishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:41
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2053; G03G15/2057; G03G15/206; G03G15/2064; G03G2215/00; G03G2215/20; G03G2215/207; G03G2215/2074
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
An electrophotographic image fixing device comprising: a heating roller, including a mandrel, and an elastic layer of 40°-60° in hardness, measured by a spring type hardness meter of JIS K6301 type, provided on the mandrel; a pressure roller arranged in contact with the heating roller and having a surface layer with a hardness equal to or higher than the hardness of the elastic layer of the heating roller; and heating means for heating and fusion-depositing a toner image onto a toner substrate passing through the nip portion between the heating roller and the pressure roller and having the toner image formed thereon; first drive means for rotating the heating roller such that the surface of the heating roller moves at a first linear speed; and second drive means for rotating the pressure roller such that the surface of the pressure roller moves at a second linear speed 1.005-1.05 times the first linear speed.
Claim 2
Dependent Claim
153 words
An electrophotographic image fixing device comprising: a heating roller, including a mandrel, and an elastic layer of 40°-60° in hardness, measured by a spring type hardness meter of JIS K6301 type, provided on the mandrel; a pressure roller arranged in contact with the heating roller and having a surface layer with a hardness equal to or higher than the hardness of the elastic layer of the heating roller; and heating means for heating and fusion-depositing a toner image onto a toner substrate passing through the nip portion between the heating roller and the pressure roller and having the toner image formed thereon; first drive means for rotating the heating roller such that the surface of the heating roller moves at a first linear speed; and second drive means for rotating the pressure roller such that the surface of the pressure roller moves at a second linear speed 1.005-1.05 times the first linear speed.
Claim 3
Dependent Claim
69 words
An electrophotographic image fixing device according to claim 1, wherein the nip portion between the heating roller and the pressure roller discharges the toner substrate such that an angle (θ), formed by the discharging direction of the toner substrate and a tangent line of the surface of the heating roller at the outlet of the nip portion between the heating roller and the pressure roller, is at least 4°.
Claim 4
Dependent Claim
17 words
An electrophotographic image fixing device according to claim 2, wherein the angle (θ) is at least 6°.
Claim 5
Dependent Claim
20 words
An electrophotographic image fixing device according to any one of claims 1-3, wherein the pressure roller is an endless belt.
Claim 6
Dependent Claim
20 words
An electrophotographic image fixing device according to any one of claims 1-3, wherein the toner image is a full-color image.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-01 | 1999-07-03 | 2000-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-01 | 2007-07-03 | 2008-01-02 | $7700.00 | Window Closed / Lapsed |