Lens module

1. A lens module, comprising:

a lens holder comprising a receiving space formed by an inner surface, a first bottom surface, a second bottom surface, and a first bevel connecting the first and second bottom surfaces;

a lens unit comprising:

a first lens having a first object-side surface, a first image-side surface, and a side surface connecting the first object-side surface to the first image-side surface, the first object-side surface comprising a first plane corresponding to the first bottom surface of the lens holder, and a second bevel abutting against the first bevel of the lens holder; the first image-side surface comprising a third plane, a first arc surface connecting to the third plane, and a fourth plane connecting with the first arc surface, and

a second lens having a second object-side surface, a second image-side surface, and a jointing surface connecting the second object-side surface to the second image-side surface; the second object-side surface including a first carrying surface abutting against the third plane of the first lens, a second arc surface engaging with the first arc surface of the first lens, and a second carrying surface corresponding to the fourth plane of the first lens;

wherein the side surface of the first lens engages with the inner surface of the lens holder.

2. The lens module as described in claim 1 , wherein the first plane of the first lens abuts against the first bottom surface of the lens holder.

3. The lens module as described in claim 1 , wherein the second carrying surface of the second lens keeps a distance from the fourth plane of the first lens.

4. The lens module as described in claim 3 further including a filter located between the second carrying surface and the fourth plane.

5. The lens module as described in claim 1 , wherein the jointing surface of the second lens keeps a distance from the inner surface of the lens holder.

6. The lens module as described in claim 1 , wherein the lens holder comprising a first holder and a second holder extending vertically from a periphery of the first holder.

7. A lens module, comprising:

a lens holder defining an optic axis, the lens holder including a first bottom surface perpendicular to the optic axis, a second bottom surface parallel to the first bottom surface, and a first bevel obliquely extending from the first bottom surface to the second bottom surface;

a lens unit comprising a first lens and a second lens;

the first lens including a second bevel located on a surface adjacent to the bottom surfaces of the lens holder and engaging with the first bevel, and a first arc surface located on a surface far away from the bottom surfaces;

the second lens including a second arc surface engaging with the first arc surface of the first lens;

a first assembly precision defined by the first bevel of the lens holder and the second bevel of the first lens for ensuring a concentricity between the lens unit and the lens holder; and

a second assembly precision defined by the first arc surface and the second arc surface for ensuring a concentricity between the first lens and the second lens,

wherein the lens holder including an inner surface perpendicular to the optic axis for abutting against a side surface of the first lens.

8. The lens module as described in claim 7 , wherein the lens holder comprising a first holder having a first thickness along a direction perpendicular to the optic axis, and a second holder having a second thickness along the direction, the first thickness being greater than the second thickness.

9. The lens module as described in claim 7 further including a filter located between the first lens and the second lens.

10. The lens module as described in claim 7 , wherein the second lens includes a jointing surface keeping a distance from the inner surface of the lens holder.

11. A lens module, comprising:

a lens holder including a sidewall having an inner surface and a top wall extending from a top of the sidewall, the top wall having a bottom surface;

a receiving space formed by the inner surface of the sidewall and the bottom surface of the top wall;

a lens unit accommodated in the receiving space, the lens unit including a first lens adjacent to the top wall and a second lens attached to the first lens, the first lens including a first object-side surface and a first image-side surface, the second lens including a second object-side surface adjacent to the first object-side surface and a second image-side surface opposed to the second object-side surface;

a first complementary configuration arranged between the first lens and the top wall of the lens holder for ensuring a concentricity between the lens unit and the lens holder, and

a second complementary configuration arranged between the first lens and the second lens for ensuring a concentricity between the first lens and the second lens,

wherein the first lens further includes a side surface abutting against the inner surface of the sidewall of the lens holder.

12. The lens module as described in claim 11 , wherein the first complementary configuration includes a first bevel disposed on the bottom surface of the top wall and a second bevel disposed on the first object-side surface.

13. The lens module as described in claim 11 , wherein the second complementary configuration includes a first arc surface on the first image-side surface of the first lens and a second arc surface on the second object-side surface.

14. The lens module as described in claim 11 , wherein the second lens further includes a jointing surface parallel to the side surface of the first lens and keeping a distance from the inner surface of the sidewall.

15. The lens module as described in claim 11 further comprising a gap between the first image-side surface and the second object-side surface.