| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image display device whose illumination optical system is simplified in constitution and which is made small-sized and enables a high- contrast image to be observed. <P>SOLUTION: The image display device is equipped with a reflection type display element 5 and an ocular optical system 2 and in the optical path from the reflection type display element 5 to an exit pupil 1 of the ocular optical system 2, a light guide plate 4 is arranged to internally guide illumination light introduced from a light source 7 arranged at a peripheral part, emit the illumination light toward the reflection type display element 5, and transmit display light from the reflection type display element 5. Here, the retardation quantity of the medium of the light guide plate 4 in display light transmission is R<SB>1</SB>= d(n<SB>e</SB>-n<SB>o</SB>) (where n<SB>e</SB>is the extraordinary light beam refractive index of the medium, n<SB>o</SB>is the ordinary light beam refractive index, and (d) is the thickness of the medium) and the retardation quantity R<SB>1</SB>of the medium per d=10 mm is ≤60 nm. <P>COPYRIGHT: (C)2004,JPO |
