Camera optical lens

1. A camera optical lens, comprising, from an object side to an image side:

a first lens having a positive refractive power;

a second lens having a negative refractive power;

a third lens having a negative refractive power;

a fourth lens having a negative refractive power;

a fifth lens having a positive refractive power; and

a sixth lens having a negative refractive power,

wherein the camera lens comprises a total of six lenses,

wherein at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, or the sixth lens comprises a free-form surface, and

wherein the camera optical lens satisfies following conditions:

f 3/ f 1≤−1.50;

−8.50≤ f 2/ f≤− 1.50;

4.00≤( R 7+ R 8)/( R 7− R 8)≤16.00; and

R 9/ R 10≤−1.50,

where

f denotes a focal length of the camera optical lens,

f1 denotes a focal length of the first lens,

f2 denotes a focal length of the second lens,

f3 denotes a focal length of the third lens,

R7 denotes a curvature radius of an object-side surface of the fourth lens,

R8 denotes a curvature radius of an image-side surface of the fourth lens,

R9 denotes a curvature radius of an object-side surface of the fifth lens, and

R10 denotes a curvature radius of an image-side surface of the fifth lens.

2. The camera optical lens as described in claim 1 , further satisfying a following condition:

0.30≤ d 6/ d 8≤1.00,

where

d6 denotes an on-axis distance from an image-side surface of the third lens to the object-side surface of the fourth lens, and

d8 denotes an on-axis distance from the image-side surface of the fourth lens to an object-side surface of the fifth lens.

3. The camera optical lens as described in claim 1 , wherein the first lens comprises an object-side surface being convex in a paraxial region, and further satisfying following conditions:

0.47≤ f 1/ f≤ 1.83;

−4.50≤( R 1+ R 2)/( R 1− R 2)≤−0.64; and

0.05≤ d 1/ TTL≤ 0.22,

where

R1 denotes a curvature radius of an object-side surface of the first lens,

R2 denotes a curvature radius of an image-side surface of the first lens,

d1 denotes an on-axis thickness of the first lens, and

TTL denotes a total optical length from the object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

4. The camera optical lens as described in claim 1 , wherein the second lens comprises an object-side surface being convex in a paraxial region and an image-side surface being concave in the paraxial region, and further satisfying following conditions:

1.58≤( R 3+ R 4)/( R 3− R 4)≤12.63; and

0.02≤ d 3/ TTL≤ 0.07,

where

R3 denotes a curvature radius of an object-side surface of the second lens,

R4 denotes a curvature radius of an image-side surface of the second lens,

d3 denotes an on-axis thickness of the second lens, and

TTL denotes a total optical length from an object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

5. The camera optical lens as described in claim 1 , further satisfying following conditions:

−186.28≤ f 3/ f≤− 1.35;

−20.14≤( R 5+ R 6)/( R 5− R 6)≤1.99; and

0.03≤ d 5/ TTL≤ 0.17,

where

R5 denotes a curvature radius of an object-side surface of the third lens,

R6 denotes a curvature radius of an image-side surface of the third lens,

d5 denotes an on-axis thickness of the third lens, and

TTL denotes a total optical length from an object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

6. The camera optical lens as described in claim 1 , wherein the fourth lens comprises an object-side surface being convex in a paraxial region and an image-side surface being concave in the paraxial region, and further satisfying following conditions:

−23.84≤ f 4/ f≤− 1.23; and

0.02≤ d 7/ TTL≤ 0.08,

where

f4 denotes a focal length of the fourth lens,

d7 denotes an on-axis thickness of the fourth lens, and

TTL denotes a total optical length from an object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

7. The camera optical lens as described in claim 1 , wherein the fifth lens comprises an object-side surface being convex in a paraxial region and an image-side surface being concave in the paraxial region, and further satisfying following conditions:

0.22≤ f 5/ f≤ 1.06

0.16≤( R 9+ R 10)/( R 9− R 10)≤1.49; and

0.08≤ d 9/ TTL≤ 0.32,

where

f5 denotes a focal length of the fifth lens,

R9 denotes a curvature radius of an object-side surface of the fifth lens,

R10 denotes a curvature radius of an image-side surface of the fifth lens,

d9 denotes an on-axis thickness of the fifth lens, and

TTL denotes a total optical length from an object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

8. The camera optical lens as described in claim 1 , wherein the sixth lens comprises an object-side surface being convex in a paraxial region and an image-side surface being concave in the paraxial region, and further satisfying following conditions:

−1.21≤ f 6/ f≤− 0.37;

0.07≤( R 11+ R 12)/( R 11− R 12)≤1.19; and

0.04≤ d 11/ TTL≤ 0.13,

where

f6 denotes a focal length of the sixth lens,

R11 denotes a curvature radius of an object-side surface of the sixth lens,

R12 denotes a curvature radius of an image-side surface of the sixth lens,

d11 denotes an on-axis thickness of the sixth lens, and

TTL denotes a total optical length from an object-side surface of the first lens to an image plane of the camera optical lens along an optic axis.

9. The camera optical lens as described in claim 1 , further satisfying a following condition:

Fno ≤1.91,

where

Fno denotes an F number of the camera optical lens.