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CN-121995603-A - Low-light level lens

CN121995603ACN 121995603 ACN121995603 ACN 121995603ACN-121995603-A

Abstract

The application discloses a low-light-level lens, which comprises a first lens group with positive focal power and a second lens group with positive focal power, wherein the first lens group comprises a first lens with negative focal power, a second lens with negative focal power and a third lens with positive focal power, the second lens group comprises a fourth lens with positive focal power, a fifth lens with negative focal power, a sixth lens with positive focal power, a seventh lens with positive focal power, an eighth lens with negative focal power and a ninth lens with positive focal power, the combined focal power of the fourth lens, the fifth lens and the sixth lens is phi 456, the combined focal power of the seventh lens, the eighth lens and the ninth lens is phi 789, and the focal power of the low-light-level lens is phi, wherein phi 456/phi 0.425,0.245 is more than or equal to 0.245. By adopting the technical scheme, the design of the micro-lens with a larger aperture can be realized by reasonably setting the number of lens groups, the number of lenses, the focal power collocation mode of the lens groups, the focal power collocation mode of the lenses and specific numerical values.

Inventors

  • MIAO ZHAO
  • JING JIAO
  • HE JIANWEI

Assignees

  • 东莞市宇瞳光学科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260325

Claims (10)

  1. 1. A low-light lens is characterized by comprising a first lens group and a second lens group which are sequentially arranged from an object plane to an image plane along an optical axis; The focal power of the first lens group is positive, and the first lens group comprises a first lens with negative focal power, a second lens with negative focal power and a third lens with positive focal power; the optical power of the second lens group is positive, and the second lens group comprises a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with negative optical power and a ninth lens with positive optical power, wherein the number of lenses with optical power in the low-light-level lens is nine; the combined focal power of the fourth lens, the fifth lens and the sixth lens is phi 456, the combined focal power of the seventh lens, the eighth lens and the ninth lens is phi 789, and the focal power of the micro-lens is phi; Wherein, phi 456/phi is more than or equal to 0.245 and less than or equal to 0.425,0.245 and phi 789/phi is more than or equal to 0.385.
  2. 2. The micro-lens of claim 1, wherein the first lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are all glass spherical lenses; the second lens, the seventh lens, the eighth lens and the ninth lens are all plastic aspheric lenses.
  3. 3. The micro-lens of claim 1, wherein the first lens comprises a first object side surface near the object plane side and a first image side surface near the image plane side, the first object side surface being a plane, the first image side surface being a concave surface; the second lens comprises a second object side surface close to one side of the object plane and a second image side surface close to one side of the image plane, the second object side surface is a concave surface, and the second image side surface is a convex surface; the third lens comprises a third object side surface close to one side of the object plane and a third image side surface close to one side of the image plane, the third object side surface is a convex surface, and the third image side surface is a convex surface; The fourth lens comprises a fourth object side surface close to one side of the object plane and a fourth image side surface close to one side of the image plane, wherein the fourth object side surface is a convex surface, and the fourth image side surface is a convex surface; The fifth lens comprises a fifth object side surface close to one side of the object plane and a fifth image side surface close to one side of the image plane, wherein the fifth object side surface is a concave surface, and the fifth image side surface is a concave surface; The sixth lens comprises a sixth object side surface close to one side of the object plane and a sixth image side surface close to one side of the image plane, wherein the sixth object side surface is a convex surface, and the sixth image side surface is a convex surface; The seventh lens comprises a seventh object side surface close to the object plane side and a seventh image side surface close to the image plane side, the seventh object side surface is hyperboloid and is a convex surface at a paraxial position, and the seventh image side surface is hyperboloid and is a concave surface at a paraxial position; the eighth lens comprises an eighth object side surface close to one side of the object plane and an eighth image side surface close to one side of the image plane, the eighth object side surface is a concave surface, and the eighth image side surface is a convex surface; The ninth lens comprises a ninth object side surface close to the object plane side and a ninth image side surface close to the image plane side, wherein the ninth object side surface is a convex surface, and the ninth image side surface is a concave surface.
  4. 4. The micro-lens of claim 1, wherein the first lens group has an optical power of Φa, the second lens group has an optical power of Φb, and the micro-lens has an optical power of Φ; wherein, phi A/phi is more than or equal to 0.065 and less than or equal to 0.185,0.435 and phi B/phi is more than or equal to 0.525.
  5. 5. The micro-lens of claim 1, wherein the first lens has a power of Φ1, the second lens has a power of Φ2, the third lens has a power of Φ3, the seventh lens has a power of Φ7, the eighth lens has a power of Φ8, the ninth lens has a power of Φ9, and the micro-lens has a power of Φ; Wherein the method comprises the steps of ,-0.645≤φ1/φ≤-0.485,-0.205＜φ2/φ≤-0.125,0.345≤φ3/φ≤0.445,0.005≤φ7/φ≤0.065,-0.055＜φ8/φ≤-0.005,0.205≤φ9/φ≤0.365.
  6. 6. The micro-lens of claim 1, wherein the fourth lens, the fifth lens and the sixth lens are arranged in a cemented configuration.
  7. 7. The micro-lens of claim 4, wherein the fourth lens, the fifth lens and the sixth lens have a center thickness d456; Wherein phi 456/d456 is more than or equal to 0.455 and less than or equal to 0.685.
  8. 8. The micro-lens system of claim 1, wherein the second lens element has an image-side surface with a center length d23 from the object-side surface of the third lens element, the third lens element has an image-side surface with a center length d34 from the object-side surface of the fourth lens element, and the sum of the center thicknesses of the second and third lens elements is t23; wherein (d23+d34)/t23 is more than or equal to 0.385 and less than or equal to 0.645.
  9. 9. The micro-lens of claim 1, wherein the micro-lens has an optical total length TTL and an effective focal length F; Wherein F/TTL is more than or equal to 0.158 and less than or equal to 0.168.
  10. 10. The micro-lens of claim 1, wherein the optical back focal length of the micro-lens is BFL and the total optical length is TTL; wherein BFL/TTL is more than or equal to 0.085 and less than or equal to 0.135.

Description

Low-light level lens Technical Field The embodiment of the invention relates to the technical field of optical devices, in particular to a micro-lens. Background With the rapid development of technology, the requirements for the optical lens are higher and higher. The maximum aperture of the existing lens in the market can reach about FNo1.0, and the imaging effect can still meet the common low-light environment. However, the light transmission capability of the scene with extremely weak ambient light is still unsatisfactory. In order to meet the requirements of higher pixels and stronger micro-light imaging effects, the research direction of an imaging lens with larger aperture and higher resolution becomes a new hot spot. At present, the aperture of a few lenses can reach Fno0.85, but the total length of the lenses is generally more than 60mm, and the application occasions are usually in the infrared field, so that the lenses have no practical value for security monitoring. The aperture of a part of lenses on the current security monitoring market can reach Fno0.85, and the focal length is generally equivalent to 2.8mm and equivalent to 4.0mm. The equivalent focal length is 6.0mm, the aperture Fno0.85 and the security monitoring lens with smaller total length are fewer. Disclosure of Invention The invention provides a micro-lens system which realizes the purposes that the equivalent focal length is 6.0mm, the aperture Fno is 0.85, the total length TTL is less than 51.0mm, and the imaging range can be matched with a 1/1.8 inch chip. The embodiment of the invention provides a micro-light lens, which comprises a first lens group and a second lens group which are sequentially arranged from an object plane to an image plane along an optical axis; The focal power of the first lens group is positive, and the first lens group comprises a first lens with negative focal power, a second lens with negative focal power and a third lens with positive focal power; the optical power of the second lens group is positive, and the second lens group comprises a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with negative optical power and a ninth lens with positive optical power, wherein the number of lenses with optical power in the low-light-level lens is nine; the combined focal power of the fourth lens, the fifth lens and the sixth lens is phi 456, the combined focal power of the seventh lens, the eighth lens and the ninth lens is phi 789, and the focal power of the micro-lens is phi; Wherein, phi 456/phi is more than or equal to 0.245 and less than or equal to 0.425,0.245 and phi 789/phi is more than or equal to 0.385. Optionally, the first lens, the third lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses; the second lens, the seventh lens, the eighth lens and the ninth lens are all plastic aspheric lenses. Optionally, the first lens includes a first object side surface near the object plane side and a first image side surface near the image plane side, where the first object side surface is a plane, and the first image side surface is a concave surface; the second lens comprises a second object side surface close to one side of the object plane and a second image side surface close to one side of the image plane, the second object side surface is a concave surface, and the second image side surface is a convex surface; the third lens comprises a third object side surface close to one side of the object plane and a third image side surface close to one side of the image plane, the third object side surface is a convex surface, and the third image side surface is a convex surface; The fourth lens comprises a fourth object side surface close to one side of the object plane and a fourth image side surface close to one side of the image plane, wherein the fourth object side surface is a convex surface, and the fourth image side surface is a convex surface; The fifth lens comprises a fifth object side surface close to one side of the object plane and a fifth image side surface close to one side of the image plane, wherein the fifth object side surface is a concave surface, and the fifth image side surface is a concave surface; The sixth lens comprises a sixth object side surface close to one side of the object plane and a sixth image side surface close to one side of the image plane, wherein the sixth object side surface is a convex surface, and the sixth image side surface is a convex surface; The seventh lens comprises a seventh object side surface close to the object plane side and a seventh image side surface close to the image plane side, the seventh object side surface is hyperboloid and is a convex surface at a paraxial position, and the seventh image side surface is hyperboloid and is a concave surface at a paraxial position; the eighth lens compris