Optical lens
An optical lens includes a first lens group with negative refractive power, a second lens group with positive refractive power, and an aperture stop disposed between the first lens group and the second lens group. A number of lenses with refractive power of the first lens group is smaller than three, and a number of lenses with refractive power of the second lens group is smaller than five. The second lens group has a lens with a diffractive optical surface, and the lens with a diffractive optical surface satisfies the condition: 0<|(Φd*V)/Φr|<2, where Φd denotes refractive power of the diffractive optical surface, Φr denotes refractive power of the lens, and V denotes an Abbe number of the lens with a diffractive optical surface.
1. An optical lens, comprising:
a first lens group with negative refractive power and a second lens group with positive refractive power, a number of lenses with refractive power of the first lens group being smaller than three, and a number of lenses with refractive power of the second lens group being smaller than five; and
an aperture stop disposed between the first lens group and the second lens group, wherein the second lens group has a lens with a diffractive optical surface, and the lens with a diffractive optical surface satisfies the condition:
0<|(Φ d*V )/Φ r|< 2
where Φd denotes refractive power of the diffractive optical surface, Φr denotes refractive power of the lens with the diffractive optical surface, and V denotes an Abbe number of the lens with the diffractive optical surface.
2. The optical lens as claimed in claim 1 , wherein the lens with a diffractive optical surface satisfies the condition:
20< V< 60.
3. The optical lens as claimed in claim 1 , wherein the first lens group comprises an aspheric lens with positive refractive power and an aspheric lens with negative refractive power.
4. The optical lens as claimed in claim 1 , wherein the lens with a diffractive optical surface is an aspheric lens.
5. The optical lens as claimed in claim 1 , wherein a lens of the second lens group nearest the aperture stop is a spherical lens.
6. The optical lens as claimed in claim 5 , wherein the spherical lens satisfies the condition:
V> 70,
where V denotes an Abbe number of the spherical lens.
7. The optical lens as claimed in claim 1 , wherein a focus shift of the optical lens is smaller than 8 μm, where the focus shift is defined as a shift in a focal plane of 850 nm infrared light relative to a standard focal plane, and the standard focal plane is a focal plane of 555 nm or 587 nm green light passing through the optical lens.
8. An optical lens, comprising:
a first lens group with negative refractive power and comprising two lenses with refractive power,
a second lens group with positive refractive power and comprising three lenses with refractive power, one of the three lenses having a diffractive optical surface, and the first lens group and the second lens group being arranged in order from a magnified side to a minified side; and
an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies the condition:
|(0.5* IMA )/(EFL*TAN( X ))−1|<0.3
where EFL denotes an effective focal length for visible light, IMA denotes a maximum image circle of an image plane formed at an effective focal length for visible light, and X denotes half of a maximum field of view.
9. The optical lens as claimed in claim 8 , wherein the lens having a diffractive optical surface satisfies the condition:
20< V< 60,
where V denotes an Abbe number of the lens.
10. The optical lens as claimed in claim 8 , wherein the second lens group comprises an aspheric lens with positive refractive power and an aspheric lens with negative refractive power.
11. The optical lens as claimed in claim 8 , wherein the lens having a diffractive optical surface is an aspheric lens.
12. The optical lens as claimed in claim 8 , wherein a lens of the second lens group nearest the aperture stop is a spherical lens.
13. The optical lens as claimed in claim 12 , wherein the spherical lens satisfies the condition:
V> 70,
where V denotes an Abbe number of the spherical lens.
14. The optical lens as claimed in claim 8 , wherein a focus shift of the optical lens is smaller than 8 μm, where the focus shift is defined as a shift in a focal plane of 850 nm infrared light relative to a standard focal plane, and the standard focal plane is a focal plane of 555 nm or 587 nm green light passing through the optical lens.
15. An optical lens, comprising:
a first lens group with negative refractive power, a number of lenses with refractive power of the first lens group being smaller than three;
a second lens group with positive refractive power, a number of lenses with refractive power of the second lens group being smaller than five, and the second lens group having a lens with a diffractive optical surface; and
an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies the condition:
TTL/ IMA <3.3
where TTL denotes a total track length of the optical lens, and IMA denotes a maximum image circle of an image plane formed at an effective focal length for visible light.
16. The optical lens as claimed in claim 15 , wherein the lens with a diffractive optical surface satisfies the condition:
20< V< 60,
where V denotes an Abbe number of the lens.
17. The optical lens as claimed in claim 15 , wherein the first lens group comprises an aspheric lens with positive refractive power and an aspheric lens with negative refractive power, and the second lens group comprises an aspheric lens with positive refractive power and an aspheric lens with negative refractive power.
18. The optical lens as claimed in claim 15 , wherein the lens with a diffractive optical surface is an aspheric lens.
19. The optical lens as claimed in claim 15 , wherein a lens of the second lens group nearest the aperture stop is a spherical lens, and the spherical lens satisfies the condition:
V> 70,
where V denotes an Abbe number of the spherical lens.
20. The optical lens as claimed in claim 15 , wherein a focus shift of the optical lens is smaller than 8 μm, where the focus shift is defined as a shift in a focal plane of 850 nm infrared light relative to a standard focal plane, and the standard focal plane is a focal plane of 555 nm or 587 nm green light passing through the optical lens.