US5172273A
Expired / Lapsed
US
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Zoom lens system
Assignee: Olympus Corp
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Filing: 1991-02-27
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Granted: 1992-12-15
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Expires: 2011-02-27
Abstract
Abstract A zoom lens system comprising, in the order from the object side, a first lens unit having a positive refractive power, a second lens unit having a positive or negative refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a negative refractive power, adapted so as to perform variation of focal length by moving said lens units along the optical axis, and adapted so as to perform focusing by moving at least one of the lens units other than said first lens unit. This zoom lens system can be focused on an object located at a very short distance.
Inventors
- 👤 Takanori Yamanashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:11
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/144; G02B15/1441; G02B15/144105; G02B15/144107; G02B15/16; G02B15/163; G02B15/167; G02B15/173
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
A zoom lens system consisting of, in order from the object side: a first lens unit having a positive refractive power, a second lens unit having a positive or negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power, wherein said zoom lens system varies focal length by moving said lens units in a direction along the optical axis, and wherein said zoom lens system performs focusing by moving at least one lens component disposed in said second lens unit, said third lens unit and said fourth lens unit in the direction along the optical axis while keeping said first lens unit fixed on the optical axis.
Claim 2
Dependent Claim
119 words
A zoom lens system consisting of, in order from the object side: a first lens unit having a positive refractive power, a second lens unit having a positive or negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power, wherein said zoom lens system varies focal length by moving said lens units in a direction along the optical axis, and wherein said zoom lens system performs focusing by moving at least one lens component disposed in said second lens unit, said third lens unit and said fourth lens unit in the direction along the optical axis while keeping said first lens unit fixed on the optical axis.
Claim 3
Dependent Claim
48 words
A zoom lens system according to claim 1 wherein said zoom lens system performs focusing by moving said fourth lens unit in the direction along the optical axis while keeping said first lens unit, said second lens unit and said third lens unit fixed on the optical axis.
Claim 4
Dependent Claim
96 words
A zoom lens system according to claim 2 wherein said zoom lens system varies focal length thereof from a wide position to a tele position by moving said first lens unit, said second lens unit, said third lens unit and said fourth lens unit toward the object side so as to widen the airspace reserved between said first lens unit and said second lens unit, and narrow the airspace reserved between said second lens unit and said third lens unit as well as the airspace reserved between said third lens unit and said fourth lens unit.
Claim 5
Dependent Claim
54 words
A zoom lens system according to claim 3 satisfying the following condition (1): β.sub.4T >|β.sub.3T |, β.sub.4T >|β.sub.2T | (1) wherein the reference symbols β 2T , β 3T and β 4T represent the magnifications of the second lens unit, the third lens unit and the fourth lens unit respectively at the tele position.
Claim 6
Dependent Claim
50 words
A zoom lens system according to claim 1 wherein said zoom lens system performs focusing by moving said second lens unit and said third lens unit integrally in the direction along the optical axis while keeping said first lens unit and said fourth lens unit fixed on the optical axis.
Claim 7
Dependent Claim
123 words
A zoom lens system comprising, in order from the object side: a first lens unit having a positive refractive power, a second lens unit having a positive or negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power, wherein said zoom lens performs variation of focal length from a wide position to a tele position by moving each of said lens units along the optical axis toward the object side, and wherein said zoom lens system performs focusing by moving at least one lens component disposed in said second lens unit, said third lens unit and said fourth lens unit along the optical axis while keeping said first lens unit fixed.
Claim 8
Dependent Claim
123 words
A zoom lens system comprising, in order from the object side: a first lens unit having a positive refractive power, a second lens unit having a positive or negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power, wherein said zoom lens performs variation of focal length from a wide position to a tele position by moving each of said lens units along the optical axis toward the object side, and wherein said zoom lens system performs focusing by moving at least one lens component disposed in said second lens unit, said third lens unit and said fourth lens unit along the optical axis while keeping said first lens unit fixed.
Claim 9
Dependent Claim
48 words
A zoom lens system according to claim 6 wherein said zoom lens system performs focusing by moving said fourth lens unit in the direction along the optical axis while keeping said first lens unit, said second lens unit and said third lens unit fixed on the optical axis.
Claim 10
Dependent Claim
96 words
A zoom lens system according to claim 7 wherein said zoom lens system varies focal length thereof from a wide position to a tele position by moving said first lens unit, said second lens unit, said third lens unit and said fourth lens unit toward the object side so as to widen the airspace reserved between said first lens unit and said second lens unit, and narrow the airspace reserved between said second lens unit and said third lens unit as well as the airspace reserved between said third lens unit and said fourth lens unit.
Claim 11
Dependent Claim
54 words
A zoom lens system according to claim 8 satisfying the following condition (1): β.sub.4T >|β.sub.3T |, β.sub.4T >|β.sub.2T | (1) wherein the reference symbols β 2T , β 3T and β 4T represent the magnifications of the second lens unit, the third lens unit and the fourth lens unit respectively at the tele position.
Claim 12
Dependent Claim
50 words
A zoom lens system according to claim 6 wherein said zoom lens system performs focusing by moving said second lens unit and said third lens unit integrally in the direction along the optical axis while keeping said first lens unit and said fourth lens unit fixed on the optical axis.
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) | 1995-12-15 | 1996-06-15 | 1996-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-15 | 2000-06-15 | 2000-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-15 | 2004-06-15 | 2004-12-15 | $7700.00 | Window Closed / Lapsed |