Lens system, wide-angle lens, optical apparatus equipped with lens system, and method for manufacturing lens system
First Claim
1. A lens system comprising, in order from an object side:
- a first lens constructed by a negative meniscus lens having a convex surface facing the object side;
a cemented lens component having positive refractive power as a whole constructed by a second lens having positive refractive power cemented with a third lens having negative refractive power;
a fourth lens having negative refractive power;
a fifth lens having positive refractive power; and
a sixth lens having positive refractive power, andthe following conditional expression being satisfied;
0.01<
d2/(−
f1)<
0.15where d2 denotes a distance along an optical axis between the first lens and the second lens, and f1 denotes a focal length of the first lens.
1 Assignment
0 Petitions
Accused Products
Abstract
With comprising, in order from an object side: a first lens L1 constructed by a negative meniscus lens having a convex surface facing the object side; a cemented lens component CL1 having positive refractive power as a whole constructed by a second lens L2 having positive refractive power and a third lens L3 having negative refractive power; a fourth lens L4 having negative refractive power; a fifth lens L5 having positive refractive power; and a sixth lens L6 having positive refractive power, and the following expression being satisfied:
0.01<d2/(−f1)<0.15
where d2 denotes a distance along an optical axis between the first lens and the second lens, and f1 denotes a focal length of the first lens, a compact lens system having superb optical performance with correcting various aberrations, a wide-angle lens, an optical apparatus equipped therewith, and a method for manufacturing the lens system are provided.
-
Citations
16 Claims
-
1. A lens system comprising, in order from an object side:
-
a first lens constructed by a negative meniscus lens having a convex surface facing the object side; a cemented lens component having positive refractive power as a whole constructed by a second lens having positive refractive power cemented with a third lens having negative refractive power; a fourth lens having negative refractive power; a fifth lens having positive refractive power; and a sixth lens having positive refractive power, and the following conditional expression being satisfied;
0.01<
d2/(−
f1)<
0.15where d2 denotes a distance along an optical axis between the first lens and the second lens, and f1 denotes a focal length of the first lens. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
where r1 denotes a radius of curvature of the object side lens surface of the first lens, and r2 denotes a radius of curvature of the image side lens surface of the first lens.
-
-
3. The lens system according to claim 1, wherein an aperture stop is disposed between the cemented lens component and the fourth lens.
-
4. The lens system according to claim 1, wherein the following conditional expression is satisfied:
-
0.0<
fb/fa<
1.2where fa denotes a focal length at d-line of a front lens group composed of the first lens and the cemented lens component, and fb denotes a focal length at d-line of a rear lens group composed of the fourth lens, the fifth lens and the sixth lens.
-
-
5. The lens system according to claim 1, wherein the following conditional expression is satisfied:
-
−
0.25<
(rb+r3)/(rb−
r3)<
0.00where rb denotes a radius of curvature of the image side lens surface of the fifth lens, and r3 denotes a radius of curvature of the object side lens surface of the second lens.
-
-
6. The lens system according to claim 1, wherein the following conditional expression is satisfied:
-
0.7<
D/f<
1.2where D denotes a distance along the optical axis between the object side lens surface of the first lens and the image side lens surface of the sixth lens, and f denotes a focal length of the lens system.
-
-
7. The lens system according to claim 1, wherein at least one lens surface of the sixth lens is an aspherical surface.
-
8. The lens system according to claim 1, wherein the fourth lens is cemented with the fifth lens.
-
9. A wide-angle lens having a configuration of the lens system according to claim 1.
-
10. An optical apparatus equipped with the lens system according to claim 1.
-
11. A method for manufacturing a lens system comprising steps of:
-
disposing, in order from an object side, a first lens constructed by a negative meniscus lens having a convex surface facing the object side, a cemented lens component constructed by a second lens having positive refractive power cemented with a third lens having negative refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, and a sixth lens having positive refractive power; and disposing each lens with satisfying the following conditional expression;
0.01<
d2/(−
f1)<
0.15where d2 denotes a distance along the optical axis between the first lens and the second lens, and f1 denotes a focal length at d-line of the first lens. - View Dependent Claims (12, 13, 14, 15, 16)
where r1 denotes a radius of curvature of the object side lens surface of the first lens, and r2 denotes a radius of curvature of the image side lens surface of the first lens.
-
-
13. The method according to claim 11, further comprising a step of:
disposing an aperture stop between the cemented lens component and the fourth lens.
-
14. The method according to claim 11, further comprising a step of:
-
disposing each lens with satisfying the following conditional expression;
0.0<
fb/fa<
1.2where fa denotes a focal length at d-line of a front lens group composed of the first lens and the cemented lens component, and fb denotes a focal length at d-line of a rear lens group composed of the fourth lens, the fifth lens and the sixth lens.
-
-
15. The method according to claim 11, further comprising a step of:
-
disposing each lens with satisfying the following conditional expression;
−
0.25<
(rb+r3)/(rb−
r3)<
0.00where rb denotes a radius of curvature of the image side lens surface of the fifth lens, and r3 denotes a radius of curvature of the object side lens surface of the second lens.
-
-
16. The method according to claim 11, further comprising a step of:
-
disposing each lens with satisfying the following conditional expression;
0.7<
D/f<
1.2where D denotes a distance along the optical axis between the object side lens surface of the first lens and the image side lens surface of the sixth lens, and f denotes a focal length of the lens system.
-
Specification