USRE45592EExpiredUtility
Photographing lens
Est. expiryDec 30, 2022(expired)· nominal 20-yr term from priority
Inventors:Young Woo Park
G02B 13/18G02B 13/22G02B 27/286G02B 13/004G02B 9/34G02B 13/16G02B 15/173
75
PatentIndex Score
2
Cited by
13
References
14
Claims
Abstract
The present invention is directed to a photographing lens containing, in order from an object side: a first lens having a positive refractive power and a convex surface facing the object side; a second lens having a negative refractive power; a third lens having a positive refractive power; and a fourth lens having a negative refractive power and at least one aspheric surface, the photographing lens satisfying the following conditional expressions: L T f ≤ 1.2 0.5 ≤ f 3 f ≤ 1.0 where L T denotes the distance on the optical axis between the object side of the first lens and the image side of the fourth lens; f denotes the total focal length of the photographing lens; and f 3 denotes the focal length of the third lens.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A photographing lens comprising, in order from an object side:
a first lens having a positive refractive power and a convex surface facing the object side;
a second lens, separate from the first lens, having a negative refractive power;
a third lens having a positive refractive power, aspheric surfaces on both sides, and a concave surface on the object side; and
a fourth lens having a negative refractive power and at least one aspheric surface surfaces on both sides,
the photographing lens satisfying the following conditional expressions:
0.75
<
f
1
/
f
<
2.0
L
T
f
≤
1.2
0.5
≤
f
3
f
≤
1.0
wherein L T denotes the distance on the optical axis between the object side of the first lens and the image side of the fourth lens; f denotes the total focal length of the photographing lens; f 1 denotes the focal length of the first lens; and f 3 denotes the focal length of the third lens.
2. The photographing lens as claimed in claim 1 , wherein the third lens has at least one aspheric surface.
3. The photographing lens as claimed in claim 1 , wherein the photographing lens further satisfies the following conditional expressions expression:
[
0.5
≤
f
1
f
≤
2.0
]
[
-
1.2
≤
f
2
f
≤
-
0.4
]
-
1.2
≤
f
2
/
f
≤
-
0.4
wherein f 1 denotes the focal length of the first lens; and f 2 denotes the focal length of the second lens.
4. The photographing lens as claimed in claim 1 , wherein the photographing lens further satisfies the following conditional expressions:
|n 3 −n 4 |≧0.1
wherein n 3 denotes the refractive index of the third lens; and n 4 denotes the refractive index of the fourth lens.
5. The photographing lens as claimed in claim 1 , wherein the photographing lens further satisfies the following conditional expressions:
-
20
≤
f
4
f
≤
-
1
wherein f 4 denotes the focal length of the fourth lens.
6. The photographing lens as claimed in claim 1, wherein the photographing lens satisfies the following expression:
0.85<f 1 /f<2.0.
7. The photographing lens as claimed in claim 1, wherein the photographing lens comprises an iris diaphragm located on the object side of the first lens.
8. A photographing lens comprising, in order from an object side:
a first lens having a positive refractive power, a convex surface facing the object side, and aspheric surfaces on both sides; a second lens having a negative refractive power; a third lens having a positive refractive power and a concave surface on the object side; and a fourth lens having a negative refractive power and aspheric surfaces on both sides, the photographing lens satisfying the following conditional expressions:
0.75<f 1 /f<2.0
L
T
f
≤
1.2
0.5
≤
f
3
f
≤
1.0
wherein L T denotes the distance on the optical axis between the object side of the first lens and the image side of the fourth lens; f denotes the total focal length of the photographing lens; f 1 denotes the focal length of the first lens; and f 3 denotes the focal length of the third lens.
9. The photographing lens as claimed in claim 8, wherein the photographing lens satisfies the following conditional expression:
0.85<f 1 /f<2.0.
10. The photographing lens as claimed in claim 8, wherein the photographing lens comprises an iris diaphragm located on the object side of the first lens.
11. A photographing lens comprising, in order from an object side:
a first lens having a positive refractive power and a convex surface facing the object side; a second lens having a negative refractive power; a third lens having a positive refractive power; and a fourth lens having a negative refractive power and at least one aspheric surface, the photographing lens satisfying the following conditional expressions:
0.85
<
f
1
/
f
<
2.0
L
T
f
≤
1.2
0.5
≤
f
3
f
≤
1.0
wherein L T denotes the distance on the optical axis between the object side of the first lens and the image side of the fourth lens; f denotes the total focal length of the photographing lens; f 1 denotes the focal length of the first lens; and f 3 denotes the focal length of the third lens.
12. The photographing lens as claimed in claim 11, wherein the photographing lens comprises an iris diaphragm located on the object side of the first lens.
13. The photographing lens as claimed in claim 10, wherein the third lens has aspheric surfaces on both sides and the fourth lens has aspheric surfaces on both sides.
14. The photographing lens as claimed in claim 10, wherein the first lens has aspheric surfaces on both sides and the fourth lens has aspheric surfaces on both sides.Join the waitlist — get patent alerts
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