Annular optical component, camera lens and image capturing unit

1. An annular optical component, comprising a plastic element and a metal element disposed on the plastic element, the plastic element comprising a plastic part, and the metal element comprising a metal part;

wherein the plastic part comprises at least part of an inner annular surface of the annular optical component, the plastic part surrounds a central axis of the annular optical component so as to form a central opening, at least part of the metal part comprises at least part of an outer annular surface of the annular optical component, the outer annular surface and the inner annular surface are opposite to each other, an object-side surface of the annular optical component faces an object side direction of the annular optical component and is connected to the outer annular surface and the inner annular surface, an image-side surface of the annular optical component faces an image-side direction of the annular optical component and is connected to the outer annular surface and the inner annular surface, and the image-side surface and the object-side surface are opposite to each other;

wherein a thickness of the metal part on the outer annular surface is d, the maximum thickness of the annular optical component is t, and the following condition is satisfied:

0.05< d/t< 1.0.

2. The annular optical component of claim 1 , wherein the metal element is insert-molded with the plastic element.

3. The annular optical component of claim 2 , wherein the metal element comprises at least one folding structure.

4. The annular optical component of claim 3 , wherein the quantity of the at least one folding structure is equal to or larger than two.

5. The annular optical component of claim 4 , wherein a distance between the at least one folding structures in a direction perpendicular to the central axis of the annular optical component is s, the thickness of the metal part on the outer annular surface is d, and the following condition is satisfied:

0.6< s/d< 3.0.

6. The annular optical component of claim 2 , wherein the metal part of the metal element extends from the outer annular surface to at least one of the object-side surface and the image-side surface, and the metal part on one of the object-side surface and the image-side surface is exposed.

7. The annular optical component of claim 6 , wherein the metal part extends from the outer annular surface only to one of the object-side surface and the image-side surface.

8. The annular optical component of claim 1 , wherein the plastic element comprises a chemical compound fiber.

9. A camera lens, comprising the annular optical component of claim 1 and an imaging lens assembly, wherein the annular optical component is disposed in the imaging lens assembly.

10. The camera lens of claim 9 , wherein the imaging lens assembly comprises an object-side lens element and an image-side lens element, and the annular optical component is disposed between the object-side lens element and the image-side lens element.

11. The camera lens of claim 10 , further comprising a light blocking film which is disposed between the image-side lens element and the annular optical component.

12. The camera lens of claim 11 , wherein the central opening of the annular optical component is tapered from the image-side surface to the object-side surface.

13. The camera lens of claim 11 , wherein the thickness of the metal part on the outer annular surface is d, the maximum thickness of the annular optical component is t, and the following condition is satisfied:

0.05< d/t< 0.6.

14. The camera lens of claim 11 , wherein the plastic part of the plastic element comprises the entire inner annular surface of the annular optical component.