Patent US4408031A successfully refreshed from Google Patents.
Patent US5587840A successfully refreshed from Google Patents.
US5587840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zoom lens
Assignee: Canon Inc
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Filing: 1995-07-24
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Granted: 1996-12-24
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Expires: 2015-07-24
Abstract
Abstract A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, totaling four lens units, wherein, when zooming from the wide-angle end to the telephoto end, the lens units move axially in such relation that the air separation between the first lens unit and the second lens unit increases, the air separation between the second lens unit and the third lens unit increases and the air separation between the third lens unit and the fourth lens unit decreases.
Inventors
- 👤 Yoshinori Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:56
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/144; G02B15/1445; G02B15/144507
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
105 words
A zoom lens comprising, from front to rear, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a negative refractive power, wherein zooming from a wide-angle end to a telephoto end is performed in such a manner that an air separation between said first lens unit and said second lens unit increases, an air separation between said second lens unit and said third lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases.
Claim 2
Dependent Claim
105 words
A zoom lens comprising, from front to rear, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a negative refractive power, wherein zooming from a wide-angle end to a telephoto end is performed in such a manner that an air separation between said first lens unit and said second lens unit increases, an air separation between said second lens unit and said third lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases.
Claim 3
Dependent Claim
17 words
A zoom lens according to claim 1, wherein focusing is performed by moving said third lens unit.
Claim 4
Dependent Claim
25 words
A zoom lens according to claim 1, further comprising a stop positioned in a space between said second lens unit and said third lens unit.
Claim 5
Dependent Claim
17 words
A zoom lens according to claim 3, wherein said stop is fixed to said third lens unit.
Claim 6
Dependent Claim
61 words
A zoom lens according to claim 1, satisfying the following condition: -3×10.sup.-2 <hh.sub.3t /(f.sub.t -f.sub.w)<2×10.sup.-2 where f w : the shortest focal length of the entire system; f t : the longest focal length of the entire system; and hh 3t : the interval between principal points of said third lens unit and said fourth lens unit in the telephoto end.
Claim 7
Dependent Claim
67 words
A zoom lens according to claim 1, satisfying the following condition: 0.1<(d.sub.1t -d.sub.1w)/f.sub.w <0.9 where f w : the shortest focal length of the entire system; d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end; and d 1t : the air separation between said first lens unit and said second lens unit in the telephoto end.
Claim 8
Dependent Claim
48 words
A zoom lens according to claim 1, satisfying the following condition: 3.0×10.sup.-3 <d.sub.1w /f.sub.w <0.2 where f w : the shortest focal length of the entire system; and d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end.
Claim 9
Dependent Claim
56 words
A zoom lens according to claim 1, satisfying the following condition: 3<d.sub.1t /d.sub.1w <50 where d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end; and d 1t : the air separation between said first lens unit and said second lens unit in the telephoto end.
Claim 10
Dependent Claim
56 words
A zoom lens according to claim 1, satisfying the following condition: 2<d.sub.2t /d.sub.2w <10 where d 2w : the air separation between said second lens unit and said third lens unit in the wide-angle end; and d 2t : the air separation between said second lens unit and said third lens unit in the telephoto end.
Claim 11
Dependent Claim
38 words
A zoom lens according to claim 1, satisfying the following condition: -90<f.sub.1 /f.sub.w <-3 where f 1 : the focal length of said first lens unit; and f w : the shortest focal length of the entire system.
Claim 12
Dependent Claim
38 words
A zoom lens according to claim 1, satisfying the following condition: -0.8<f.sub.4 /f.sub.w <-0.3 where f 4 : the focal length of said fourth lens unit; and f w : the shortest focal length of the entire system.
Claim 13
Dependent Claim
54 words
A zoom lens according to claim 1, satisfying the following condition: 2.0<β.sub.4t /β.sub.4w <5.0 where β 4w : the magnification for an infinitely distant object of said fourth lens unit in the wide-angle end; and β 4t : the magnification for the infinitely distant object of said fourth lens unit in the telephoto end.
Claim 14
Dependent Claim
17 words
A zoom lens according to claim 1, further comprising a stop fixed to said second lens unit.
Claim 15
Dependent Claim
23 words
A zoom lens according to claim 3, wherein said stop is arranged to move in unison with said fourth lens unit during zooming.
Claim 16
Dependent Claim
22 words
A zoom lens according to claim 1, wherein said second lens unit moves in unison with said fourth lens unit during zooming.
Claim 17
Dependent Claim
103 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein focusing is performed by moving said third lens unit.
Claim 18
Dependent Claim
103 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein focusing is performed by moving said third lens unit.
Claim 19
Dependent Claim
105 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein focusing is performed by moving all said lens units in unison.
Claim 20
Dependent Claim
105 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein focusing is performed by moving all said lens units in unison.
Claim 21
Dependent Claim
104 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein said fourth lens unit has at least one aspheric surface.
Claim 22
Dependent Claim
104 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein said fourth lens unit has at least one aspheric surface.
Claim 23
Dependent Claim
114 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein said third lens unit includes at least one positive lens having an aspheric surface and at least one negative lens.
Claim 24
Dependent Claim
114 words
A zoom lens comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of positive refractive power and a fourth lens unit of negative refractive power, wherein, when zooming from a wide-angle end to a telephoto end, said lens units are made to move in such relation that an air separation between said first lens unit and said second lens unit increases and an air separation between said third lens unit and said fourth lens unit decreases, and wherein said third lens unit includes at least one positive lens having an aspheric surface and at least one negative lens.
Claim 25
Dependent Claim
23 words
A zoom lens according to any one of claims 16 to 18, wherein said third lens unit has at least one aspheric surface.
Claim 26
Dependent Claim
27 words
A zoom lens according to any one of claims 16 to 19, wherein said first to fourth lens units, during zooming, all move toward an object side.
Claim 27
Dependent Claim
22 words
A zoom lens according to any one of claims 16 to 19, wherein said third lens unit has a stop included therein.
Claim 28
Dependent Claim
25 words
A zoom lens according to any one of claims 16 to 19, wherein a frontmost lens in said fourth lens unit is a negative lens.
Claim 29
Dependent Claim
41 words
A zoom lens according to claim 18, wherein said fourth lens unit is constructed with a single lens of negative refractive power whose front surface is formed to aspheric such that the negative refracting power gets progressively weaker toward the margin.
Claim 30
Dependent Claim
66 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: -3×10.sup.-2 <hh.sub.3t /(f.sub.t -f.sub.w)<2×10.sup.-2 where f w : the shortest focal length of the entire system; f t : the longest focal length of the entire system; and hh 3t : the interval between principal points of said third lens unit and said fourth lens unit in the telephoto end.
Claim 31
Dependent Claim
72 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: 0.1<(d.sub.1t -d.sub.1w)/f.sub.w <0.9 where f w : the shortest focal length of the entire system; d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end; and d 1t : the air separation between said first lens unit and said second lens unit in the telephoto end.
Claim 32
Dependent Claim
53 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: 3.0×10.sup.-3 <d.sub.1w /f.sub.w <0.2 where f w : the shortest focal length of the entire system; and d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end.
Claim 33
Dependent Claim
61 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: 3<d.sub.1t /d.sub.1w <50 where d 1w : the air separation between said first lens unit and said second lens unit in the wide-angle end; and d 1t : the air separation between said first lens unit and said second lens unit in the telephoto end.
Claim 34
Dependent Claim
61 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: 2<d.sub.2t /d.sub.2w <10 where d 2w : an air separation between said second lens unit and said third lens unit in the wide-angle end; and d 2t : an air separation between said second lens unit and said third lens unit in the telephoto end.
Claim 35
Dependent Claim
43 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: -90<f.sub.1 /f.sub.w <-3 where f 1 : the focal length of said first lens unit; and f w : the shortest focal length of the entire system.
Claim 36
Dependent Claim
43 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: -0.8<f.sub.4 /f.sub.w <-0.3 where f 4 : the focal length of said fourth lens unit; and f w : the shortest focal length of the entire system.
Claim 37
Dependent Claim
59 words
A zoom lens according to any one of claims 16 to 19, satisfying the following condition: 2.0<β.sub.4t /β.sub.4w <5.0 where β 4w : the magnification for an infinitely distant object of said fourth lens unit in the wide-angle end; and β 4t : the magnification for the infinitely distant object of said fourth lens unit in the telephoto end.
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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) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |