Small wide-angle lens system
Disclosed is a small wide-angle lens system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens sequentially arranged from an object, wherein the first lens has a convex object-side surface, the third lens has a negative refractive power, the fourth lens has a concave image-side surface, the sixth lens has a concave object-side surface and a concave image-side surface, the ninth lens has a negative refractive power and a concave object-side surface, all surfaces of the first to ninth lenses are aspherical surfaces, the refractive power P1 of the first lens satisfies |P1|<0.01, and Fno of the lens system satisfies Fno<1.6.
1. A small wide-angle lens system comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens sequentially arranged from an object, wherein
the first lens has a convex object-side surface,
the third lens has a negative refractive power,
the fourth lens has a concave image-side surface,
the sixth lens has a concave object-side surface and a concave image-side surface,
the ninth lens has a negative refractive power and a concave object-side surface,
all surfaces of the first to ninth lenses are aspherical surfaces,
a refractive power P1 of the first lens satisfies |P1|<0.01, and
Fno of the lens system satisfies Fno<1.6.
2. The small wide-angle lens system according to claim 1 , wherein a minimum value CTm of a central thickness of the lens system satisfies CTm≤0.4.
3. The small wide-angle lens system according to claim 1 , wherein a ratio of a central thickness CT9 of the ninth lens to an edge thickness ET9 of an effective diameter of the ninth lens satisfies 0.15<CT9/ET9<1.0.
4. The small wide-angle lens system according to claim 1 , wherein a half field of view HFOV of the lens system satisfies 38°<HFOV<50°.
5. The small wide-angle lens system according to claim 1 , wherein, assuming that an angle of incidence of light incident on an edge of an effective diameter of an image-side surface of the ninth lens is A92, A92 satisfies A92<12°.
6. The small wide-angle lens system according to claim 1 , wherein a focal distance f4 of the fourth lens, a focal distance f5 of the fifth lens, a focal distance f6 of the sixth lens, and a focal distance f7 of the seventh lens satisfy (|f5|+|f6|)/(|f4|+|f7|)<7.
7. The small wide-angle lens system according to claim 1 , wherein at least one inflection point is provided at the object-side surface and an image-side surface of the first lens.
8. The small wide-angle lens system according to claim 1 , wherein the number NVd40 of lenses having a variance constant of 40 or more satisfies NVd40≥3.
9. The small wide-angle lens system according to claim 1 , wherein a radius of curvature R3 of an object-side surface of the second lens, a radius of curvature R4 of an image-side surface of the second lens, a radius of curvature R5 of an object-side surface of the third lens, and a radius of curvature R6 of an image-side surface of the third lens satisfy 0.5<|(R3+R4)|/|(R5+R6)|<2.0.
10. The small wide-angle lens system according to claim 1 , wherein a ratio of a distance TL from a center of the object-side surface of the first lens to an image surface to an image surface height ImagH satisfies TL/ImagH<1.7.
11. A small wide-angle lens system comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens sequentially arranged from an object, wherein
a stop is located between the first lens and the second lens,
the first lens has a convex object-side surface,
the third lens has a negative refractive power and a concave image-side surface,
the fifth lens has a negative refractive power, a concave object-side surface, and a convex image-side surface,
the sixth lens has a concave object-side surface and a concave image-side surface,
the ninth lens has a negative refractive power and a concave object-side surface,
all surfaces of the first to ninth lenses are aspherical surfaces,
a refractive power P1 of the first lens satisfies |P1|<0.01, and
assuming that an angle of incidence of light incident on an edge of an effective diameter of an image-side surface of the ninth lens is A92, A92 satisfies A92<12°.
12. The small wide-angle lens system according to claim 11 , wherein Fno of the lens system satisfies Fno<1.6.
13. The small wide-angle lens system according to claim 11 , wherein a radius of curvature R3 of an object-side surface of the second lens, a radius of curvature R4 of an image-side surface of the second lens, a radius of curvature R5 of an object-side surface of the third lens, and a radius of curvature R6 of the image-side surface of the third lens satisfy 0.5<|(R3+R4)|/|(R5+R6)|<2.0.
14. The small wide-angle lens system according to claim 11 , wherein a ratio of a distance TL from a center of the object-side surface of the first lens to an image surface to an image surface height ImagH satisfies TL/ImagH<1.7.
15. The small wide-angle lens system according to claim 11 , wherein at least one inflection point is provided at the object-side surface and an image-side surface of the first lens.
16. The small wide-angle lens system according to claim 11 , wherein the number NVd40 of lenses having a variance constant of 40 or more satisfies NVd40≥3.
17. The small wide-angle lens system according to claim 11 , wherein a minimum value CTm of a central thickness of the lens system satisfies CTm≤0.4.
18. The small wide-angle lens system according to claim 11 , wherein a half field of view HFOV of the lens system satisfies 38°<HFOV<50°.
19. The small wide-angle lens system according to claim 11 , wherein a ratio of a central thickness CT9 of the ninth lens to an edge thickness ET9 of an effective diameter of the ninth lens satisfies 0.15<CT9/ET9<1.0.
20. The small wide-angle lens system according to claim 11 , wherein a focal distance f4 of the fourth lens, a focal distance f5 of the fifth lens, a focal distance f6 of the sixth lens, and a focal distance f7 of the seventh lens satisfy (|f5|+|f6|)/(|f4|+|f7|)<7.