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US 9,568,712 B2Granted
Miniature telephoto lens assembly
AssigneeCorephotonics Ltd.
InventorsMichael Dror, Ephraim Goldenberg, Gal Shabtay
Life of this patent
Estimating the term…
Abstract
An optical lens assembly includes five lens elements and provides a TTL/EFL<1.0. In an embodiment, the focal length of the first lens element f1<TTL/2, an air gap between first and second lens elements is smaller than half the second lens element thickness, an air gap between the third and fourth lens elements is greater than TTL/5 and an air gap between the fourth and fifth lens elements is smaller than about 1.5 times the fifth lens element thickness. All lens elements may be aspheric.
Claims19
A lens assembly, comprising:
- a plurality of refractive lens elements arranged along an optical axis, wherein at least one surface of at least one of the plurality of lens elements is aspheric, wherein the lens assembly has an effective focal length (EFL), a total track length (TTL) of 6.5 millimeters or less and a ratio TTL/EFL of less than 1.0, and wherein the plurality of lens elements comprises, in order from an object side to an image side, a first lens element with a focal length f1 and positive refractive power, a second lens element with a focal length f2 and negative refractive power and a third lens element with a focal length f3, the focal length f1, the focal length f2 and the focal length f3 fulfilling the condition 1.2×|f3|>|f2|>1.5×f1.
A lens assembly, comprising:
- a plurality of refractive lens elements arranged along an optical axis, wherein the lens assembly has an effective focal length (EFL) and a total track length (TTL) smaller than the effective focal length (EFL), the plurality of refractive lens elements comprising, in order from an object plane to an image plane along the optical axis, a first lens element having positive optical power, a pair of second and third lens elements having together a negative optical power, and a combination of fourth and fifth lens elements, the fourth lens element separated from the third lens element by an air gap greater than TTL/5.
Dependencies are inferred from the claim text.