Miniature lens assembly and method of making same
A lens assembly includes at least a pair of lenses fixed in a lens barrel and an additional lens initially having at least one degree of freedom of movement with respect to the other lenses. The additional lens can be fixed in a desired alignment position with respect to the other lenses.
1. A lens assembly comprising:
a first plurality of lenses;
a lens barrel configured to receive and fixedly align the first plurality of lenses; and
at least one additional lens positioned between one of the first plurality of lenses and an aperture of the lens barrel and having at least one degree of freedom of movement with respect to the first plurality of lenses within a gap defined between the lens barrel and the at least one additional lens to accommodate movement of the at least one additional lens in the at least one degree of freedom of movement to fix the at least one additional lens in a desired alignment position with respect to the first plurality of lenses;
wherein, the at least one additional lens is positioned nearest the aperture.
2. The lens assembly according to claim 1 , wherein the gap permits at least one degree of freedom orthogonal to an optical axis of the lens assembly.
3. The lens assembly according to claim 2 , wherein the at least one additional lens is fixedly connectable to the barrel.
4. The lens assembly according to claim 2 , wherein the at least one additional lens is fixedly connectable to one of the first plurality of lenses.
5. The lens assembly according to claim 2 , further comprising at least one baffle and wherein the at least one additional lens is fixedly connectable to one baffle.
6. The lens assembly according to claim 2 , wherein the gap permits movement of 5 to 50 microns.
7. The lens assembly according to claim 1 , wherein the at least one additional lens extends outside of one end of the lens barrel.
8. The lens assembly according to claim 7 , wherein the at least one additional lens is fixedly connectable to one of the first plurality of lenses and to the lens barrel.
9. The lens assembly according to claim 1 , wherein the at least one additional lens has a flat surface on one side facing an adjacent one of the first plurality of lenses and the adjacent one of the first plurality of lenses has a flat surface on the side facing the at least one additional lens.
10. The lens assembly according to claim 1 , wherein the at least one additional lens is the lens in the lens assembly furthest away from an image plane of the lens assembly.
11. The lens assembly according to claim 1 , wherein the at least one additional lens is the lens in the lens assembly closest to an image plane of the lens assembly.
12. The lens assembly according to claim 1 , wherein the at least one additional lens is movable along an optical axis of the lens barrel into the desired position.
13. The lens assembly according to claim 1 , wherein the degree of freedom of movement along the optical axis is up to 100 microns.
14. The lens assembly according to claim 1 , wherein the at least one additional lens is fixable in position by epoxy.
15. The lens assembly according to claim 1 , wherein the at least one additional lens is fixable in position by a weld.