Patent ID: 11867920
Assignee: ASIA OPTICAL CO., INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 9:
10. The projecting related device as claimed in claim 9, wherein:
the projection lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens sequentially arranged from a projection side to an image source side along an optical axis;
the first lens is with positive refractive power, has a concave surface or a convex surface facing the projection side, and has a convex surface facing the image source side;
the second lens is with negative refractive power, and has a concave surface facing the projection side and another concave surface facing the image source side;
the third lens is with positive refractive power, and has a convex surface facing the projection side and another convex surface facing the image source side;
the fourth lens is with positive refractive power, and has a convex surface facing the projection side and another convex surface facing the image source side;
the fifth lens is with negative refractive power, and has a concave surface facing the projection side and another concave surface facing the image source side.