Optical imaging lens

1. An optical imaging lens, sequentially comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element from an object side to an image side along an optical axis, wherein each of the first lens element to the sixth lens element comprises an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through;

the first lens element is arranged to be a lens element in a first order from the object side to the image side and the first lens element has negative refracting power;

the second lens element is arranged to be a lens element in a second order from the object side to the image side;

the third lens element is arranged to be a lens element in a third order from the object side to the image side;

the fourth lens element is arranged to be a lens element in a fourth order from the object side to the image side;

the fifth lens element is arranged to be a lens element in a fifth order from the object side to the image side;

the sixth lens element is arranged to be a lens element in a first order from the image side to the object side;

wherein at least one of the object-side surfaces and the image-side surfaces of the first lens element to the sixth lens element is a free form surface, the free form surface is crossed by a first reference plane at a first curve, wherein the first reference plane contains the optical axis; the free form surface is crossed by a second reference plane at a second curve, wherein the second reference plane contains the optical axis; and the first reference plane and the second reference plane intersect at the optical axis without overlapping, and when the first curve on the first reference plane is rotated onto the second reference plane with the optical axis as the rotation axis, the first curve and the second curve do not coincide;

the optical imaging lens satisfies the following conditional expression: ImgH/(T1+G12+T2)≥4.200, wherein ImgH is an image height of the optical imaging lens, T1 is a thickness of the first lens element along the optical axis, G12 is a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, and T2 is a thickness of the second lens element along the optical axis.

2. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: (T5+T6)/T4≥3.600, wherein T5 is a thickness of the fifth lens element along the optical axis, T6 is a thickness of the sixth lens element along the optical axis, and T4 is a thickness of the fourth lens element along the optical axis.

3. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: (G23+T3)/T1≥1.500, wherein G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, and T3 is a thickness of the third lens element along the optical axis.

4. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: ALT/(T1+G34)≥3.800, wherein ALT is a sum of thicknesses of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element along the optical axis, and G34 is a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis.

5. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: TTL/(AAG+T4)≥2.800, wherein TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, AAG is a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis, and T4 is a thickness of the fourth lens element along the optical axis.

6. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: (T1+T5)/(G12+T2)≥2.100, wherein T5 is a thickness of the fifth lens element along the optical axis.

7. The optical imaging lens according to claim 1 , wherein the optical imaging lens further satisfies the following conditional expression: (T4+G45)/G23≥2.000, wherein T4 is a thickness of the fourth lens element along the optical axis, G45 is a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis.

8. An optical imaging lens, sequentially comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element from an object side to an image side along an optical axis, wherein each of the first lens element to the sixth lens element comprises an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through;

the first lens element is arranged to be a lens element in a first order from the object side to the image side;

the second lens element is arranged to be a lens element in a second order from the object side to the image side;

the third lens element is arranged to be a lens element in a third order from the object side to the image side;

the fourth lens element is arranged to be a lens element in a fourth order from the object side to the image side and the fourth lens element has negative refracting power;

the fifth lens element is arranged to be a lens element in a fifth order from the object side to the image side;

the sixth lens element is arranged to be a lens element in a first order from the image side to the object side;

wherein at least one of the object-side surfaces and the image-side surfaces of the first lens element to the sixth lens element is a free form surface, the free form surface is crossed by a first reference plane at a first curve, wherein the first reference plane contains the optical axis; the free form surface is crossed by a second reference plane at a second curve, wherein the second reference plane contains the optical axis; and the first reference plane and the second reference plane intersect at the optical axis without overlapping, and when the first curve on the first reference plane is rotated onto the second reference plane with the optical axis as the rotation axis, the first curve and the second curve do not coincide;

the optical imaging lens satisfies the following conditional expression: ImgH/(T1+G12+T2)≥4.200, wherein ImgH is an image height of the optical imaging lens, T1 is a thickness of the first lens element along the optical axis, G12 is a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, T2 is a thickness of the second lens element along the optical axis.

9. The optical imaging lens according to claim 8 , wherein the optical imaging lens further satisfies the following conditional expression: T5/T1≥1.700, wherein T5 is a thickness of the fifth lens element along the optical axis.

10. The optical imaging lens according to claim 8 , wherein the optical imaging lens further satisfies the following conditional expression: EFL/(G23+G45)≤7.500, wherein EFL is an effective focal length of the optical imaging lens, G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, G45 is a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis.

11. The optical imaging lens according to claim 8 , wherein when the first curve on the first reference plane is rotated onto the second reference plane with the optical axis as the rotation axis, the maximum difference between the first curve and the second curve in a direction along the optical axis is greater than 1.000 μm.

12. The optical imaging lens according to claim 8 , wherein the optical imaging lens further satisfies the following conditional expression: (G45+T5)/G23≥5.000, wherein G45 is a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, T5 is a thickness of the fifth lens element along the optical axis, G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis.

13. The optical imaging lens according to claim 8 , wherein the optical imaging lens further satisfies the following conditional expression: (AAG+BFL)/T3≤4.500, wherein AAG is a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis, BFL is a distance from the image-side surface of the sixth lens element to an image plane along the optical axis, T3 is a thickness of the third lens element along the optical axis.

14. The optical imaging lens according to claim 8 , wherein the optical imaging lens further satisfies the following conditional expression: TL/(G56+T6)≤6.200, wherein TL is a distance from the object-side surface of the first lens element to the image-side surface of the sixth lens element along the optical axis, G56 is a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis, T6 is a thickness of the sixth lens element along the optical axis.

15. An optical imaging lens, sequentially comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element from an object side to an image side along an optical axis, wherein each of the first lens element to the sixth lens element comprises an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through;

the first lens element is arranged to be a lens element in a first order from the object side to the image side and the first lens element has negative refracting power;

the second lens element is arranged to be a lens element in a second order from the object side to the image side;

the third lens element is arranged to be a lens element in a third order from the object side to the image side;

the fourth lens element is arranged to be a lens element in a fourth order from the object side to the image side;

the fifth lens element is arranged to be a lens element in a fifth order from the object side to the image side;

the sixth lens element is arranged to be a lens element in a first order from the image side to the object side;

wherein at least one of the object-side surfaces and the image-side surfaces of the first lens element to the sixth lens element is a free form surface, the free form surface is crossed by a first reference plane at a first curve, wherein the first reference plane contains the optical axis; the free form surface is crossed by a second reference plane at a second curve, wherein the second reference plane contains the optical axis; and the first reference plane and the second reference plane intersect at the optical axis without overlapping, and when the first curve on the first reference plane is rotated onto the second reference plane with the optical axis as the rotation axis, the first curve and the second curve do not coincide;

the optical imaging lens satisfies the following conditional expression: ImgH/(G12+T2+T4)≥4.700 and AAG/(T2+G34)≤3.000, wherein ImgH is an image height of the optical imaging lens, G12 is a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, T2 is a thickness of the second lens element along the optical axis, T4 is a thickness of the fourth lens element along the optical axis, AAG is a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis, G34 is a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis.

16. The optical imaging lens according to claim 15 , wherein the optical imaging lens further satisfies the following conditional expression: (T3+T5)/G23≥5.900, wherein T3 is a thickness of the third lens element along the optical axis, T5 is a thickness of the fifth lens element along the optical axis, G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis.

17. The optical imaging lens according to claim 15 , wherein the optical imaging lens further satisfies the following conditional expression: T5/(G12+G23)≥2.400, wherein T5 is a thickness of the fifth lens element along the optical axis, G23 is a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis.

18. The optical imaging lens according to claim 15 , wherein the optical imaging lens further satisfies the following conditional expression: ALT/(G45+G56)≤7.500, wherein ALT is a sum of thicknesses of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element along the optical axis, G45 is a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis, G56 is a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis.

19. The optical imaging lens according to claim 15 , wherein the optical imaging lens further satisfies the following conditional expression: V1+V3+V4≤110.000, wherein V1 is an Abbe number of the first lens element, V3 is an Abbe number of the third lens element, V4 is an Abbe number of the fourth lens element.