Optical imaging system and camera module
An optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in order from an object side, wherein one or more of the first to sixth lenses is disposed between a stop and an imaging plane and of those, one or more has positive refractive power and one is made of a glass material, and four or more of the first to sixth lenses are made of a plastic material.
1. An optical imaging system comprising:
a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane; and
a stop disposed between the object side of the optical imaging system and the sixth lens,
wherein one lens of the first to sixth lenses is made of a glass material and is disposed between the stop and the imaging plane,
at least four lenses of the first to sixth lenses are made of a plastic material,
the second lens has a concave object-side surface in an optical axis region thereof,
the third lens has a concave object-side surface and a convex image-side surface in an optical axis region thereof, and
the optical imaging system satisfies the following conditional expressions:
Gf/f< 3.5
where f is a focal length of the optical imaging system, and Gf is a focal length of the one lens made of a glass material and disposed between the stop and the imaging plane, and
8.0< TL/f< 14
where TL is a distance from an object-side surface of the first lens to the imaging plane.
2. The optical imaging system of claim 1 , wherein the first lens has a negative refractive power.
3. The optical imaging system of claim 1 , wherein the second lens has a negative refractive power.
4. The optical imaging system of claim 1 , wherein the third lens has a positive refractive power.
5. The optical imaging system of claim 1 , wherein the fourth lens has a positive refractive power.
6. The optical imaging system of claim 1 , wherein an object-side surface of the fifth lens and an image-side surface of the fifth lens are both concave in an optical axis region thereof, or are both convex in an optical axis region thereof.
7. The optical imaging system of claim 1 , wherein the first lens has a convex object-side surface in an optical axis region thereof.
8. The optical imaging system of claim 1 , wherein the first lens has a concave image-side surface in an optical axis region thereof.
9. The optical imaging system of claim 1 , wherein the fourth lens has a convex image-side surface in an optical axis region thereof.
10. The optical imaging system of claim 1 , wherein the sixth lens has a convex image-side surface in an optical axis region thereof.
11. The optical imaging system of claim 1 , wherein another lens of the first to sixth lenses is made of a glass material.
12. A camera module comprising:
a housing having a first linear coefficient of thermal expansion;
a lens barrel having a second linear coefficient of thermal expansion and disposed in the housing; and
the optical imaging system of claim 1 ,
wherein the first to sixth lenses and the stop are disposed in the lens barrel, and
the imaging plane is disposed in the housing.
13. The optical imaging system of claim 1 , wherein the fourth lens has a convex object-side surface in an optical axis region thereof.
14. An optical imaging system comprising:
a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane; and
a stop disposed between the object side of the optical imaging system and the sixth lens,
wherein one lens of the first to sixth lenses has a positive refractive power, is made of a glass material, and is disposed between the stop and the imaging plane,
at least four lenses of the first to sixth lenses are made of a plastic material,
the second lens has a concave object-side surface in an optical axis region thereof,
the third lens has a concave object-side surface and a convex image-side surface in an optical axis region thereof, and
the optical imaging system satisfies the following conditional expressions:
Gf/f< 3.5
where f is a focal length of the optical imaging system, and Gf is a focal length of the one lens that has a positive refractive power, is made of a glass material, and is disposed between the stop and the imaging plane, and
8.0< TL/f< 14
where TL is a distance from an object-side surface of the first lens to the imaging plane.
15. The optical imaging system of claim 14 , wherein the stop is disposed between the third lens and the fourth lens.
16. The optical imaging system of claim 14 , wherein the fourth lens is the one lens that has a positive refractive power, is made of a glass material, and is disposed between the stop and the imaging plane.
17. The optical imaging system of claim 14 , wherein the first lens is made of a glass material, and
the sixth lens is the one lens that has a positive refractive power, is made of a glass material, and is disposed between the stop and the imaging plane.
18. The optical imaging system of claim 14 , wherein the second lens and the third lens are made of a plastic material.
19. A camera module comprising:
a housing having a first linear coefficient of thermal expansion, and comprising an imaging plane; and
a lens barrel having a second linear coefficient of thermal expansion disposed in the housing; and
an optical imaging system disposed in the lens barrel and configured to focus incident light on the imaging plane, the optical imaging system comprising:
a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in ascending numerical order from an object side of the optical imaging system toward the imaging plane; and
a stop disposed between the object side of the optical imaging system and the sixth lens,
wherein one lens of the first to sixth lenses is made of a glass material and five lenses of the first to sixth lenses are made of a plastic material, or two lenses of the first to sixth lenses are made of a glass material and four lenses of the first to sixth lenses are made of a plastic material,
the one lens made of a glass material is disposed between the stop and the imaging plane, or one lens of the two lenses made of a glass material is disposed between the stop and the imaging plane,
the second lens has a concave object-side surface in an optical axis region thereof,
the third lens has a concave object-side surface and a convex image-side surface in an optical axis region thereof, and
the optical imaging system satisfies the following conditional expressions:
Gf/f< 3.5
where f is a focal length of the optical imaging system, and Gf is a focal length of the one lens made of a glass material and disposed between the stop and the imaging plane, or the one lens of the two lenses made of a glass material and disposed between the stop and the imaging plane, and
8.0< TL/f< 14
where TL is a distance from an object-side surface of the first lens to the imaging plane.
20. The camera module of claim 19 , wherein the stop is disposed between the third lens and the fourth lens.