Imaging lens
An imaging lens includes a first lens, a second lens and a third lens arranged in order from an object side to an image side. The imaging lens satisfies the conditions of 0.07 mm<dBFL<0.17 mm and 1<DL/LT<1.79, where dBFL denotes a distance between a focal plane formed by light with a wavelength of 587 nm and a focal plane formed by light with a wavelength of 940 nm on an optical axis of the imaging lens when a subject to be captured is at infinity, DL is a lens diameter of the third lens, LT is a distance measured on the optical axis of the imaging lens between an object-side surface of the first lens and an image-side surface of the third lens.
1 . An imaging lens, comprising:
a first lens having positive refractive power, a second lens and a third lens arranged in order from an object side to an image side of the imaging lens; and
an aperture stop disposed between the object side and the second lens, wherein the second lens and the third lens are aspheric lenses, a total number of lenses with refractive powers of the imaging lens is at most five, the three lenses closest to the image side of the imaging lens have respective refractive powers of positive, positive, and negative in order from the object side to the image side, a horizontal field of view of the imaging lens ranges from 40 to 67 degrees, an interval between every two adjacent lenses in the imaging lens is fixed, and the imaging lens satisfies the following conditions:
(1) 0.07 mm<dBFL<0.17 mm; and
(2) 1<DL/LT<1.79, where dBFL denotes a distance between a focal plane formed by light with a wavelength of 587 nm and a focal plane formed by light with a wavelength of 940 nm on an optical axis of the imaging lens when a subject to be captured is at infinity, DL is a lens diameter of the third lens, LT is a distance measured on the optical axis of the imaging lens between an object-side surface of the first lens and an image-side surface of the third lens.
2 . The imaging lens as claimed in claim 1 , wherein a center part of the object-side surface of the first lens is convex, and a center part of the image-side surface of the third lens is concave.
3 . The imaging lens as claimed in claim 1 , wherein the imaging lens satisfies a condition of 0.58<D 1 /LT<1.17, where D 1 is a lens diameter of the first lens.
4 . The imaging lens as claimed in claim 1 , wherein the first lens has a refractive index greater than 1.7 and an Abbe number less than 50.
5 . The imaging lens as claimed in claim 1 , wherein a total number of lenses with refractive powers of the imaging lens is three, four or five.
6 . The imaging lens as claimed in claim 1 , wherein an F-number of the imaging lens ranges from 1.6 to 2.4.
7 . The imaging lens as claimed in claim 1 , wherein the first lens is made of glass, and at least one of the second lens and the third lens is made of plastic.
8 . The imaging lens as claimed in claim 1 , wherein a thermal drift of the imaging lens is less than 15 μm, where the thermal drift is an offset of a focal plane at 105° C. relative to a focal plane at 25° C. of the imaging lens.
9 . An imaging lens, comprising:
a first lens, wherein the first lens is a lens with a positive refractive power closest to a magnified side of the imaging lens;
a second lens with a refractive power;
a third lens, wherein the third lens is a lens with a refractive power closest to a minified side of the imaging lens; and
an aperture stop disposed between the magnified side and the second lens, wherein the imaging lens includes at least two aspheric lenses, a total number of lenses with refractive powers of the imaging lens is at most five, the three lenses closest to the minified side of the imaging lens have respective refractive powers of positive, positive, and negative in order from the object side to the minified side, a horizontal field of view of the imaging lens ranges from 40 to 67 degrees, and the imaging lens satisfies the following conditions:
(1) 0.07 mm<dBFL<0.17 mm; and
(2) 0.48<D 1 /DL<0.77, where dBFL denotes a distance between a focal plane formed by light with a wavelength of 587 nm and a focal plane formed by light with a wavelength of 940 nm on an optical axis of the imaging lens when a subject to be captured is at infinity, D 1 is a lens diameter of the first lens, and DL is a lens diameter of the third lens.
10 . The imaging lens as claimed in claim 9 , wherein a center part of the magnified-side surface of the first lens is convex, and a center part of the minified-side surface of the third lens is concave.
11 . The imaging lens as claimed in claim 9 , wherein the imaging lens satisfies a condition of 0.58<D 1 /LT<1.17, where D 1 is a lens diameter of the first lens, and LT is a distance measured on the optical axis of the imaging lens between a magnified-side surface of the first lens and a minified-side surface of the third lens.
12 . The imaging lens as claimed in claim 9 , wherein the first lens has a refractive index greater than 1.7 and an Abbe number less than 50.
13 . The imaging lens as claimed in claim 9 , wherein a total number of lenses with refractive powers of the imaging lens is three, four or five.
14 . The imaging lens as claimed in claim 9 , wherein an F-number of the imaging lens ranges from 1.6 to 2.4.
15 . The imaging lens as claimed in claim 9 , wherein the first lens is made of glass, and at least one of the second lens and the third lens is made of plastic.
16 . The imaging lens as claimed in claim 9 , wherein a thermal drift of the imaging lens is less than 15 μm, where the thermal drift is an offset of a focal plane at 105° C. relative to a focal plane at 25° C. of the imaging lens.