US4241981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compact wide angle zoom lens
Assignee: Pentax Corp
•
Filing: 1979-02-14
•
Granted: 1980-12-30
•
Expires: 1999-02-14
Abstract
Abstract A compact wide angle zoom lens in order from the object side, of a divergent front lens group and a convergent rear lens group, the overall focal length being variable by mechanical movement of the front and rear lens groups. The divergent front lens group is composed, in order from the object side, of a first lens being a negative meniscus lens convex toward the object side, a second lens being a double convex positive lens or a positive cemented lens having positive and negative lenses, a third lens being a negative meniscus lens convex toward the object side, a fourth lens being a negative lens and a fifth lens being a positive lens. The convergent rear lens group is composed of a sixth lens being a positive lens, a seventh lens being a positive meniscus lens convex toward the object, an eighth lens being a double convex positive lens, a ninth lens being a double concave negative lens, the eighth and ninth lenses being cemented to each other, and the tenth lens being a positive lens. The overall lens system is composed of ten or eleven lens elements grouped into nine lens components.
Inventors
- 👤 Sadao Okudaira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:40
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/142; G02B15/1425
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
355 words
A compact wide angle zoom lens, comprising in order from the object side; a divergent front lens group and a convergent rear lens group, the overall focal length being variable by mechanical movement of the front and rear lens groups; said divergent front lens group being composed, in order from the object side, of a first lens being a negative meniscus lens convex toward the object side, a second lens being a double convex positive lens, a third lens being a negative meniscus lens convex toward the object side, a fourth lens being a negative lens and a fifth lens being a positive lens; said convergent rear lens group being composed of a sixth lens being a positive lens, a seventh lens being a positive meniscus lens convex toward the object, an eighth lens being a double convex positive lens, a ninth lens being a double concave negative lens, the eighth and ninth lenses being cemented to each other, and a tenth lens being positive lens, wherein the overall lens system composed of ten lens elements is grouped into nine lens components, the lens system satisfying the following conditions: ______________________________________
Resultant Focal Length
F = 24.7˜48.5
Lens
Thick-
ness -
Radius of Lens Refractive
Abbe
Lens Curvature Space Index No.
______________________________________
r.sub.1
279.684
d.sub.1
1.50
n.sub.1
1.88300
ν.sub.1
40.8
L.sub.1
r.sub.2
43.521
d.sub.2
3.22
r.sub.3
90.739
d.sub.3
7.30
n.sub.2
1.62004
ν.sub.2
36.3
L.sub.2
r.sub.4
-99.547
d.sub.4
0.10
r.sub.5
45.490
d.sub.5
1.40
n.sub.3
1.88300
ν.sub.3
40.8
L.sub.3
r.sub.6
18.175
d.sub.6
5.93
r.sub.7
-1067.750
d.sub.7
1.50
n.sub.4
1.64000
ν.sub.4
60.1
L.sub.4
r.sub.8
28.948
d.sub.8
2.66
r.sub.9
-26.732
d.sub.9
3.91
n.sub. 5
1.69895
ν.sub.5
30.1
L.sub.5
r.sub.10 221.127 d.sub.10
21.51˜1.06
r.sub.11
46.089
d.sub.11
2.46
n.sub.6
1.67000
ν.sub.6
57.4
L.sub.6
r.sub.12
-162.341
d.sub.12
2.40
r.sub.13
27.215
d.sub.13
1.78
n.sub.7
1.68250
ν.sub.7
44.7
L.sub.7
r.sub.14
39.045
d.sub.14
0.10
r.sub.15
20.554
d.sub.15
8.28
n.sub.8
1.59551
ν.sub.8
39.2
L.sub.8
r.sub.16
-23.131
d.sub.16
0.0
r.sub.17
-23.131
d.sub.17
2.51
n.sub.9
1.84666
ν.sub.9
23.9
L.sub.9
r.sub.18
17.116
d.sub.18
2.30
r.sub.19
-193.791
d.sub.19
2.29
n.sub.10
1.71736
ν.sub.10
29.5
L.sub.10
r.sub.20
-22.084
focal length, front group
focal length, second lens
f.sub.F = -33.039
f.sub.2 = 77.700
______________________________________
Claim 2
Dependent Claim
355 words
A compact wide angle zoom lens, comprising in order from the object side; a divergent front lens group and a convergent rear lens group, the overall focal length being variable by mechanical movement of the front and rear lens groups; said divergent front lens group being composed, in order from the object side, of a first lens being a negative meniscus lens convex toward the object side, a second lens being a double convex positive lens, a third lens being a negative meniscus lens convex toward the object side, a fourth lens being a negative lens and a fifth lens being a positive lens; said convergent rear lens group being composed of a sixth lens being a positive lens, a seventh lens being a positive meniscus lens convex toward the object, an eighth lens being a double convex positive lens, a ninth lens being a double concave negative lens, the eighth and ninth lenses being cemented to each other, and a tenth lens being positive lens, wherein the overall lens system composed of ten lens elements is grouped into nine lens components, the lens system satisfying the following conditions: ______________________________________
Resultant Focal Length
F = 24.7˜48.5
Lens
Thick-
ness -
Radius of Lens Refractive
Abbe
Lens Curvature Space Index No.
______________________________________
r.sub.1
279.684
d.sub.1
1.50
n.sub.1
1.88300
ν.sub.1
40.8
L.sub.1
r.sub.2
43.521
d.sub.2
3.22
r.sub.3
90.739
d.sub.3
7.30
n.sub.2
1.62004
ν.sub.2
36.3
L.sub.2
r.sub.4
-99.547
d.sub.4
0.10
r.sub.5
45.490
d.sub.5
1.40
n.sub.3
1.88300
ν.sub.3
40.8
L.sub.3
r.sub.6
18.175
d.sub.6
5.93
r.sub.7
-1067.750
d.sub.7
1.50
n.sub.4
1.64000
ν.sub.4
60.1
L.sub.4
r.sub.8
28.948
d.sub.8
2.66
r.sub.9
-26.732
d.sub.9
3.91
n.sub. 5
1.69895
ν.sub.5
30.1
L.sub.5
r.sub.10 221.127 d.sub.10
21.51˜1.06
r.sub.11
46.089
d.sub.11
2.46
n.sub.6
1.67000
ν.sub.6
57.4
L.sub.6
r.sub.12
-162.341
d.sub.12
2.40
r.sub.13
27.215
d.sub.13
1.78
n.sub.7
1.68250
ν.sub.7
44.7
L.sub.7
r.sub.14
39.045
d.sub.14
0.10
r.sub.15
20.554
d.sub.15
8.28
n.sub.8
1.59551
ν.sub.8
39.2
L.sub.8
r.sub.16
-23.131
d.sub.16
0.0
r.sub.17
-23.131
d.sub.17
2.51
n.sub.9
1.84666
ν.sub.9
23.9
L.sub.9
r.sub.18
17.116
d.sub.18
2.30
r.sub.19
-193.791
d.sub.19
2.29
n.sub.10
1.71736
ν.sub.10
29.5
L.sub.10
r.sub.20
-22.084
focal length, front group
focal length, second lens
f.sub.F = -33.039
f.sub.2 = 77.700
______________________________________
Claim 3
Dependent Claim
381 words
A compact wide angle zoom lens, comprising in order from the object side; a divergent front lens group and a convergent rear lens group, the overall focal length being variable by mechanical movement of the front and rear lens groups; said divergent front lens group being composed, in order from the object side, of a first lens being a negative meniscus lens convex toward the object side, a second lens being a double convex positive lens and a negative lens cemented to each other to have a positive resultant focal length, a third lens being a negative meniscus lens convex toward the object side, a fourth lens being a negative lens and a fifth lens being a positive lens; said convergent rear lens group being composed of a sixth lens being a positive lens, a seventh lens being a positive meniscus lens convex toward the object, an eighth lens being a double convex positive lens, a ninth lens being a double concave negative lens, the eighth and ninth lenses being cemented to each other, and a tenth lens being positive lens, wherein the overall lens system composed of eleven lens elements is grouped into nine lens components, the lens system satisfying the following conditions: __________________________________________________________________________
Resultant Focal Length
F = 24.7˜48.5
Lens Thickness-
Lens Radius of Curvature
Lens Space
Refractive Index
Abbe No.
__________________________________________________________________________
r.sub.1
228.536
d.sub.1
1.50 n.sub.1
1.88300
ν.sub.1
40.8
L.sub.1
r.sub.2
41.340 d.sub.2
3.67
r.sub.3
100.246
d.sub.3
5.52 n.sub.2
1.60342
ν.sub.2
38.0
L.sub.2
r.sub.4
-85.725
d.sub.4
0.0
r.sub.5
-85.725
d.sub.5
1.50 n.sub.3
1.81600
ν.sub.3
46.6
L.sub.2'
r.sub.6
-92.300
d.sub.6
0.10
r.sub.7
34.227 d.sub.7
1.40 n.sub.4
1.83481
ν.sub.4
42.7
L.sub.3
r.sub.8
16.900 d.sub.8
6.44
r.sub.9
-144.780
d.sub.9
1.42 n.sub.5
1.61800
ν.sub.5
63.4
L.sub.4
r.sub.10
29.610 d.sub.10
2.74
r.sub.11
27.353 d.sub.11
3.49 n.sub.6
1.69895
ν .sub.6
30.1
L.sub.5
r.sub.12
189.000
d.sub.12
20.12˜0.89
r.sub.13
48.070 d.sub.13
2.28 n.sub.7
1.67000
ν.sub.7
57.4
L.sub.6
r.sub.14
-148.000
d.sub.14
2.40
r.sub.15
27.832 d.sub.15
1.62 n.sub.8
1.61800
ν.sub.8
63.4
L.sub.7
r.sub.16
37.630 d.sub.16
0.10
r.sub.17
19.668 d.sub.17
8.95 n.sub.9
1.58144
ν.sub.9
40.7
L.sub.8
r.sub.18
-24.213
d.sub.18
0.0
r.sub.19
-24.213
d.sub.19
2.51 n.sub.10
1.84666
ν.sub.10
23.9
L.sub.9
r.sub.20
17.350 d.sub.20
1.92
r.sub.21
2444.907
d.sub.21
2.17 n.sub.11
1.72151
ν.sub.11
29.2
L.sub.10
r.sub.22
-23.370
__________________________________________________________________________
focal length, front group f.sub.F = -31.816
focal length, second lens f.sub.2 = 81.818
Claim 4
Dependent Claim
381 words
A compact wide angle zoom lens, comprising in order from the object side; a divergent front lens group and a convergent rear lens group, the overall focal length being variable by mechanical movement of the front and rear lens groups; said divergent front lens group being composed, in order from the object side, of a first lens being a negative meniscus lens convex toward the object side, a second lens being a double convex positive lens and a negative lens cemented to each other to have a positive resultant focal length, a third lens being a negative meniscus lens convex toward the object side, a fourth lens being a negative lens and a fifth lens being a positive lens; said convergent rear lens group being composed of a sixth lens being a positive lens, a seventh lens being a positive meniscus lens convex toward the object, an eighth lens being a double convex positive lens, a ninth lens being a double concave negative lens, the eighth and ninth lenses being cemented to each other, and a tenth lens being positive lens, wherein the overall lens system composed of eleven lens elements is grouped into nine lens components, the lens system satisfying the following conditions: __________________________________________________________________________
Resultant Focal Length
F = 24.7˜48.5
Lens Thickness-
Lens Radius of Curvature
Lens Space
Refractive Index
Abbe No.
__________________________________________________________________________
r.sub.1
228.536
d.sub.1
1.50 n.sub.1
1.88300
ν.sub.1
40.8
L.sub.1
r.sub.2
41.340 d.sub.2
3.67
r.sub.3
100.246
d.sub.3
5.52 n.sub.2
1.60342
ν.sub.2
38.0
L.sub.2
r.sub.4
-85.725
d.sub.4
0.0
r.sub.5
-85.725
d.sub.5
1.50 n.sub.3
1.81600
ν.sub.3
46.6
L.sub.2'
r.sub.6
-92.300
d.sub.6
0.10
r.sub.7
34.227 d.sub.7
1.40 n.sub.4
1.83481
ν.sub.4
42.7
L.sub.3
r.sub.8
16.900 d.sub.8
6.44
r.sub.9
-144.780
d.sub.9
1.42 n.sub.5
1.61800
ν.sub.5
63.4
L.sub.4
r.sub.10
29.610 d.sub.10
2.74
r.sub.11
27.353 d.sub.11
3.49 n.sub.6
1.69895
ν .sub.6
30.1
L.sub.5
r.sub.12
189.000
d.sub.12
20.12˜0.89
r.sub.13
48.070 d.sub.13
2.28 n.sub.7
1.67000
ν.sub.7
57.4
L.sub.6
r.sub.14
-148.000
d.sub.14
2.40
r.sub.15
27.832 d.sub.15
1.62 n.sub.8
1.61800
ν.sub.8
63.4
L.sub.7
r.sub.16
37.630 d.sub.16
0.10
r.sub.17
19.668 d.sub.17
8.95 n.sub.9
1.58144
ν.sub.9
40.7
L.sub.8
r.sub.18
-24.213
d.sub.18
0.0
r.sub.19
-24.213
d.sub.19
2.51 n.sub.10
1.84666
ν.sub.10
23.9
L.sub.9
r.sub.20
17.350 d.sub.20
1.92
r.sub.21
2444.907
d.sub.21
2.17 n.sub.11
1.72151
ν.sub.11
29.2
L.sub.10
r.sub.22
-23.370
__________________________________________________________________________
focal length, front group f.sub.F = -31.816
focal length, second lens f.sub.2 = 81.818
References Cited (Backward Citations)
US4169660A
Cited
US4153339A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-30 | 1984-06-30 | 1984-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-30 | 1988-06-30 | 1988-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-30 | 1992-06-30 | 1992-12-30 | $7700.00 | Window Closed / Lapsed |