Patent ID: 11940623
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical system configured to guide a light beam from a display element, the optical system comprising:
a positive lens;
a negative lens; and
an optical element having a transmission surface, an optical surface, and a reflection and transmission surface,
wherein the light beam from the display element;
passes through the positive lens, the negative lens, and then the transmission surface;
then reflects on the reflection and transmission surface and then on the optical surface;
then passes through the reflection and transmission surface; and

then travels to an exit pupil, and

wherein the following inequalities are satisfied:

0.28<nn-np<0.60

50.26≤vp-vn<80

where np and nn are refractive indices of the positive lens and the negative lens for the d-line, respectively, and vp and vn are Abbe numbers of the positive lens and the negative lens for the d-line, respectively.