| 摘要 |
<p>PROBLEM TO BE SOLVED: To effectively use non-diffraction light having been left unused to improve incident efficiency of light on a light guide element.SOLUTION: A first diffractive optics 30a is arranged on a light incident surface 20a of a light guide element 20, a second diffractive optics 30b is arranged on a light emission surface 20b of the light guide element 20, and a reflection film 40 is arranged on a surface of the light guide element 20 so as to be opposed to the first diffractive optics 30a. The first diffractive optics 30a and the reflection film 40 are located such that light incident on the first diffractive optics 30a without being diffracted by the first diffractive optics 30a and reflected by the reflection film 40 can be reflected and diffracted by the first diffractive optics 30a.</p> |
