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

Claim 10:
11. The projecting related device as claimed in claim 10, wherein the projection lens further includes a stop disposed between the projection side and the first lens, and the projection lens satisfies any one of the following conditions:

−1.2≤f5/f≤−0.9;

1.9≤f1/f≤3.7;

−1.1≤f2/f≤−0.6;

0.8≤f3/f≤1.2;

0.8≤f4/f≤1.1;

0.3≤f/TTL≤0.45;

0.09≤BFL/TTL≤0.22;

0.5≤IH/f≤0.65;

−17≤f23/f5≤30;

−1.15≤f4/f5≤−0.75;

−33≤f23/f≤16,

where f is an effective focal length of the projection lens, f1 is an effective focal length of the first lens, f2 is an effective focal length of the second lens, f3 is an effective focal length of the third lens, f4 is an effective focal length of the fourth lens, f5 is an effective focal length of the fifth lens, f23 is an effective focal length of combination of the second lens and the third lens, TTL is an interval from the stop to the image source side along the optical axis, BFL is an interval from the concave surface facing the image source side to the image source side along the optical axis, and IH is a half image height of the projection lens.