Optical imaging system

Patent metadata

Field	Value
Publication number	US-10215957-B2
Application number	US-201715467433-A
Country	US
Kind code	B2
Filing date	Mar 23, 2017
Priority date	Sep 12, 2016
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

An optical imaging system includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens, a fifth lens, and a sixth lens having a positive refractive power and having a convex image-side shape, sequentially arranged in a direction from an object side of the optical imaging system to an imaging plane of the optical imaging system.

First claim

What is claimed is:

1. An optical imaging system, comprising:
a first lens comprising a positive refractive power;
a second lens comprising a negative refractive power and a concave image-side surface;
a third lens comprising a negative refractive power, and a concave image-side surface;
a fourth lens comprising a convex image-side surface;
a fifth lens comprising a negative refractive power and a concave image-side surface; and
a sixth lens comprising a positive refractive power and further comprising a convex object-side shape along an optical axis of the optical imaging system,
wherein the optical imaging system satisfies the following conditional expression,
0.1< D 45/ TL< 0.7

where TL represents a distance from an object-side surface of the first lens to an imaging plane, and D45 represents a distance from an image-side surface of the fourth lens to an object-side surface of the fifth lens.

2. The optical imaging system of claim 1 , wherein the fourth lens comprises a convex object-side surface along the optical axis.

3. The optical imaging system of claim 1 , wherein the first to sixth lenses are disposed comprising an interval between each respective lens.

4. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
0.7< TL/f< 1.0
where TL represents a distance from an object-side surface of the first lens to an imaging plane, and f represents a total focal length of the optical imaging system.

5. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
0.15< R 1/ f< 0.32
where R1 represents a radius of curvature of an object-side surface of the first lens, and f represents a total focal length of the optical imaging system.

6. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
−3.5< f/f 2<−0.5

where f represents a total focal length of the optical imaging system, and f2 represents a focal length of the second lens.

7. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
1.60< Nd 6<1.75
where Nd6 represents a refractive index of the sixth lens.

8. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
0.3<tan θ<0.5

where θ represents a half angle of view of the optical imaging system.

9. The optical imaging system of claim 1 , wherein the optical imaging system satisfies the following conditional expression,
2.0< f/EPD< 2.7
where f represents a total focal length of the optical imaging system, and EPD represents a diameter of an entrance aperture.

10. An optical imaging system, comprising:
a first lens, a second lens, a third lens comprising a negative refractive power, a fourth lens, a fifth lens, and a sixth lens comprising a convex object-side surface in a paraxial portion sequentially arranged from an object side to an image side,
wherein the optical imaging system satisfies the following conditional expressions,
0.7< TL/f< 1.0
0.1< D 45/ TL< 0.7

where TL represents a distance from an object-side surface of the first lens to an imaging plane, f represents a total focal length of the optical imaging system, and D45 represents a distance from an image-side surface of the fourth lens to an object-side surface of the fifth lens.

11. The optical imaging system of claim 10 , wherein the sixth lens comprises a shape in which an image-side surface is convex along an optical axis of the optical imaging system and an inflection point is formed on the image-side surface.

Assignees

• Samsung Electro Mech

Inventors

• Lee Tae Youn
• Jo Yong Joo

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B9/62 Primary

  having six components only · CPC title

• G02B13/02

  Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length · CPC title

• G02B27/005

  for correction of secondary colour or higher-order chromatic aberrations · CPC title

• G02B23/04 Primary

  for the purpose of beam splitting or combining, e.g. fitted with eyepieces for more than one observer (G02B23/10 takes precedence) · CPC title