Patent US5644437A successfully refreshed from Google Patents.
US5644437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical system of optical information recording/reproducing apparatus
Assignee: Pentax Corp
•
Filing: 1995-09-14
•
Granted: 1997-07-01
•
Expires: 2015-09-14
Abstract
Abstract An optical system of an optical information recording/reproducing apparatus includes an objective lens for converging a generally parallel luminous flux. A chromatic aberration correction element for correcting chromatic aberration of the objective lens is provided and has substantially no power. The chromatic aberration correcting element comprises a positive lens and a negative lens positioned in the generally parallel luminous flux. The positive and negative lenses of the chromatic aberration correcting element have substantially the same refractive index and different Abbe's number.
Inventors
- 👤 Koichi Maruyama
- 👤 Makoto Iwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:07
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1372; G02; G02B; G02B27/00; G02B27/0025; G11B7/1378; G11B7/1392; G11B7/13922
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
80 words
An optical system of an optical information recording/reproducing apparatus comprising: an objective lens for converging a generally parallel luminous flux; a chromatic aberration correcting element for correcting chromatic aberration of said objective lens, said chromatic aberration correcting element having substantially no power; said chromatic aberration correcting element, comprising a positive lens and a negative lens positioned in the generally parallel luminous flux, and said positive lens and said negative lens having substantially the same refractive index and different Abbe's numbers.
Claim 2
Dependent Claim
80 words
An optical system of an optical information recording/reproducing apparatus comprising: an objective lens for converging a generally parallel luminous flux; a chromatic aberration correcting element for correcting chromatic aberration of said objective lens, said chromatic aberration correcting element having substantially no power; said chromatic aberration correcting element, comprising a positive lens and a negative lens positioned in the generally parallel luminous flux, and said positive lens and said negative lens having substantially the same refractive index and different Abbe's numbers.
Claim 3
Dependent Claim
21 words
The optical system according to claim 1, further comprising a collimator for providing the generally luminous flux to said objective lens.
References Cited (Backward Citations)
DE3237645A1
Cited
JPS5872114A
Cited
US4484803A
Cited
JPS5960743A
Cited
EP0123048A1
Cited
US4572623A
Cited
US4557564A
Cited
JPS60232519A
Cited
US4753524A
Cited
JPS6235311A
Cited
US4721373A
Cited
JPS62267933A
Cited
JPS62269922A
Cited
US4909616A
Cited
JPS6310118A
Cited
JPS6320735A
Cited
US4791265A
Cited
US4976526A
Cited
US5479296A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |