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CN-121995597-A - Optical imaging system

CN121995597ACN 121995597 ACN121995597 ACN 121995597ACN-121995597-A

Abstract

The optical imaging system includes a first lens having a refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, a fifth lens having a refractive power, and a sixth lens having a refractive power, which are sequentially disposed along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of the optical imaging system, wherein conditional expressions 0.85≤TTL/f≤1.0 and 0.5≤f1/f≤1 are satisfied, wherein TTL is a distance along the optical axis from the object side of the first lens to the imaging surface, f is a total focal length of the optical imaging system, and f1 is a focal length of the first lens.

Inventors

  • Cao Shengri
  • JIN XUEZHE
  • LIN TAIYUAN
  • JIN BINGXIAN

Assignees

  • 三星电机株式会社

Dates

Publication Date
20260508
Application Date
20250820
Priority Date
20241104

Claims (20)

  1. 1. An optical imaging system, comprising: A first lens having a refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, a fifth lens having a refractive power, and a sixth lens having a refractive power, which are disposed in order from an object side of the optical imaging system toward an imaging surface of the optical imaging system along an optical axis of the optical imaging system, Wherein the following conditional expression is satisfied: 0.85 ≤ TTL/f ≤ 1.0, 0.5 ≤ f1/f ≤ 1, Wherein TTL is the distance along the optical axis from the object side of the first lens to the imaging plane, f is the total focal length of the optical imaging system, and f1 is the focal length of the first lens, and Wherein the optical imaging system has six lenses in total.
  2. 2. The optical imaging system of claim 1, wherein the third lens has a concave image side in its paraxial region and the fourth lens has a convex object side in its paraxial region.
  3. 3. The optical imaging system of claim 1, wherein the first lens and the second lens are D-cut lenses.
  4. 4. The optical imaging system of claim 1, wherein the fifth lens has a convex image side in its paraxial region and the sixth lens has a convex object side in its paraxial region.
  5. 5. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 100 ≤ v1+v3 ≤ 120, Wherein v1 is the abbe number of the first lens and v3 is the abbe number of the third lens.
  6. 6. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 0.8 ≤ R1/R5 ≤ 1.2, Wherein R1 is a radius of curvature of the object side surface of the first lens at the optical axis, and R5 is a radius of curvature of the object side surface of the third lens at the optical axis.
  7. 7. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 0.2 < IMG HT/EPD ≤ 0.4, wherein IMG HT is half the diagonal length of the imaging plane and EPD is the diameter of the entrance pupil of the optical imaging system.
  8. 8. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 0.2 ≤ (CT1+CT2+CT3+CT4)/f ≤ 0.5, wherein CT1 is the thickness of the first lens along the optical axis, CT2 is the thickness of the second lens along the optical axis, CT3 is the thickness of the third lens along the optical axis, and CT4 is the thickness of the fourth lens along the optical axis.
  9. 9. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 0.2 ≤ D45/Td ≤ 0.4, Where D45 is the distance along the optical axis from the image side of the fourth lens element to the object side of the fifth lens element, and Td is the distance along the optical axis from the object side of the first lens element to the image side of the sixth lens element.
  10. 10. The optical imaging system of claim 1, wherein the first lens is a D-cut lens having a long axis and a short axis perpendicular to the long axis, and The following conditional expression is satisfied: 0.5 < AR1 < 1.0, wherein AR1 is equal to an aspect ratio of a maximum effective radius of an object side of the D-shaped cut lens along the long axis of the D-shaped cut lens to a maximum effective radius of the object side of the D-shaped cut lens along the short axis of the D-shaped cut lens.
  11. 11. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: 0.3 < ΣCT/TTL < 0.5, Wherein Σct is the sum of the thicknesses of the first to sixth lenses along the optical axis.
  12. 12. The optical imaging system of claim 1, wherein the following conditional expression is satisfied: -1.0 < f1/f2 < 0, Wherein f2 is the focal length of the second lens.
  13. 13. An optical imaging system, comprising: a first lens having a refractive power, A second lens having a refractive power, A third lens having positive refractive power and having a concave image side surface in a paraxial region thereof, A fourth lens having a negative refractive power and having a convex object side in a paraxial region thereof, A fifth lens having optical power, and A sixth lens having a convex object side surface in a paraxial region thereof, The first lens to the sixth lens are sequentially arranged along the optical axis of the optical imaging system from the object side of the optical imaging system towards the imaging surface of the optical imaging system; Wherein the following conditional expression is satisfied: 1.7 < f-number < 2.0, 0.2 < IMG HT/EPD ≤ 0.4, Wherein f-number is the f-number of the optical imaging system, IMG HT is half the diagonal length of the imaging plane, and EPD is the diameter of the entrance pupil of the optical imaging system, and Wherein the optical imaging system has six lenses in total.
  14. 14. The optical imaging system of claim 13, wherein the first to sixth lenses are spaced apart from each other along the optical axis by a predetermined distance, and a distance along the optical axis between the fourth and fifth lenses is greater than each of a distance along the optical axis between the first and second lenses, a distance along the optical axis between the second and third lenses, a distance along the optical axis between the third and fourth lenses, and a distance along the optical axis between the fifth and sixth lenses.
  15. 15. The optical imaging system of claim 13, wherein the following conditional expression is satisfied: 0.2 ≤ D45/Td ≤ 0.4, Where D45 is the distance along the optical axis from the image side of the fourth lens element to the object side of the fifth lens element, and Td is the distance along the optical axis from the object side of the first lens element to the image side of the sixth lens element.
  16. 16. The optical imaging system of claim 13, wherein the following conditional expression is satisfied: 0.8 ≤ R1/R5 ≤ 1.2, Wherein R1 is a radius of curvature of an object side surface of the first lens at the optical axis, and R5 is a radius of curvature of an object side surface of the third lens at the optical axis.
  17. 17. The optical imaging system of claim 13, wherein the following conditional expression is satisfied: 0.2 ≤ (CT1+CT2+CT3+CT4)/f ≤ 0.5, Wherein CT1 is the thickness of the first lens along the optical axis, CT2 is the thickness of the second lens along the optical axis, CT3 is the thickness of the third lens along the optical axis, CT4 is the thickness of the fourth lens along the optical axis, and f is the total focal length of the optical imaging system.
  18. 18. The optical imaging system of claim 13, further comprising an optical path changing member for changing a path of light provided on an object side of the first lens, Wherein one or more of the first to sixth lenses are D-cut lenses.
  19. 19. The optical imaging system of claim 13, wherein the fifth lens has positive refractive power and the sixth lens has negative refractive power.
  20. 20. The optical imaging system of claim 13, wherein the first lens is a D-cut lens having a long axis and a short axis perpendicular to the long axis, and The following conditional expression is satisfied: 0.5 < AR1 < 1.0, wherein AR1 is equal to an aspect ratio of a maximum effective radius of an object side of the D-shaped cut lens along the long axis of the D-shaped cut lens to a maximum effective radius of the object side of the D-shaped cut lens along the short axis of the D-shaped cut lens.

Description

Optical imaging system Cross Reference to Related Applications The present application claims the benefit of priority from korean patent application No. 10-2024-0154672 filed at the korean intellectual property office on month 11 and 4 of 2024, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field The present disclosure relates to optical imaging systems. Background Recently, a folded camera module having a reflecting member such as a prism in front of a lens to change a path of incident light is employed in a portable terminal. Such folded camera modules have a long overall length, so they can be used for a telephoto camera having a relatively long focal length. In general, a telephoto camera has lower resolution than a wide-angle camera and is less efficient in a low-light environment. These disadvantages are particularly apparent when capturing images at high magnification. Disclosure of Invention This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. In one general aspect, an optical imaging system includes a first lens having a refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, a fifth lens having a refractive power, and a sixth lens having a refractive power, which are sequentially disposed along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of the optical imaging system, wherein conditional expressions 0.85≤TTL/f≤1.0 and 0.5≤f1/f≤1 are satisfied, wherein TTL is a distance along the optical axis from an object side surface of the first lens to the imaging surface, f is a total focal length of the optical imaging system, and f1 is a focal length of the first lens. The third lens may have a concave image side in its paraxial region and the fourth lens may have a convex object side in its paraxial region. The first lens and the second lens may be D-cut lenses. The fifth lens may have a convex image side in its paraxial region and the sixth lens may have a convex object side in its paraxial region. The conditional expression 100 +.v1+v3 +.120 may be satisfied, where, v1 is the abbe number of the first lens, and v3 is the abbe number of the third lens. The conditional expression 0.8R 1/R5 1.2 may be satisfied, where R1 is a radius of curvature of the object-side surface of the first lens at the optical axis, and R5 is a radius of curvature of the object-side surface of the third lens at the optical axis. Conditional expression 0.2 < IMG HT/EPD +.0.4 may be satisfied, where IMG HT is half the diagonal length of the imaging plane and EPD is the diameter of the entrance pupil of the optical imaging system. The conditional expression 0.2≤ (Ct1+Ct2+Ct3+Ct4)/f≤0.5 may be satisfied, where CT1 is the thickness of the first lens along the optical axis, CT2 is the thickness of the second lens along the optical axis, CT3 is the thickness of the third lens along the optical axis, and CT4 is the thickness of the fourth lens along the optical axis. The conditional expression 0.2+.d45/td+.0.4 may be satisfied, where D45 is the distance along the optical axis from the image side of the fourth lens element to the object side of the fifth lens element and Td is the distance along the optical axis from the object side of the first lens element to the image side of the sixth lens element. The first lens may be a D-shaped cut lens having a long axis and a short axis perpendicular to the long axis, and conditional expression 0.5 < AR1 < 1.0 may be satisfied, wherein AR1 is equal to an aspect ratio of a maximum effective radius of an object side of the D-shaped cut lens along the long axis of the D-shaped cut lens to a maximum effective radius of an object side of the D-shaped cut lens along the short axis of the D-shaped cut lens. Conditional expression 0.3 < Σct/TTL < 0.5 may be satisfied, where Σct is the sum of thicknesses of the first lens to the sixth lens along the optical axis. The conditional expression-1.0 < f1/f2 < 0 may be satisfied, where f2 is the focal length of the second lens. In another general aspect, an optical imaging system includes a first lens having a refractive power, a second lens having a refractive power, a third lens having a positive refractive power and having a concave image side in a paraxial region thereof, a fourth lens having a negative refractive power and having a convex object side in a paraxial region thereof, a fifth lens having a refractive power, and a sixth lens having a convex object side in a paraxial region thereof, which are sequentially disposed along an opt