Image display apparatus and optical system

An image display apparatus comprising:

• a light source for supplying illumination light;
• a reflection type display element for modulating the illumination light into image light by reflecting the light;
• an illumination optical system for guiding the illumination light to said reflection type display element;
• and
• a projection optical system for guiding the image light to an observer,
• wherein the image light is incident on said projection optical system via at least a portion of said illumination optical system,
• said projection optical system comprises a first optical member which has at least one reflecting surface from which the image light emerges toward an eye of the observer, and a second optical member located at the observer side with respect to said first optical member, and
• at least one of conditions given by
• t1<t2
• Φ1>Φ2
• is satisfied when a ray connecting an exit pupil center of said projection optical system and a center of said reflection type display element is defined as a reference axis ray, in a plane including the reference axis ray, a ray of the image light having a maximum optical path length when the image light passes through at least a portion of the illumination optical system is represented by r1 and a ray of the image light having a minimum optical path length when the image light passes through at least a portion of the illumination optical systm is represented by r2, optical path lengths of the ray r1 and r2 in said second optical member are respectively represented by t1 and t2, and optical powers exerted on the rays r1 and r2 by said second optical member are respectively represented by Φ1 and Φ2.

An optical system comprising:

• an illumination optical system for guiding illumination light to a reflection type display element;
• and
• a projection optical system for guiding image light reflected by the reflection type display element to an observer,
• wherein the image light is incident on said projection optical system via at least a portion of said illumination optical system, and
• said projection optical system includes a member for correcting an optical path length difference between rays of the image light caused when the image light is incident on said projection optical system via at least a portion of said illumination optical system.

An optical system comprising:

• an illumination optical system for guiding illumination light to a reflection type display element;
• and
• a projection optical system for guiding image light reflected by the reflection type display element to an observer,
• wherein the image light is incident on said projection optical system via at least a portion of said illumination optical system,
• said projection optical system comprises a first optical member which has at least one reflecting surface from which the image light emerges toward an eye of the observer, and a second optical member located at the observer side with respect to said first optical member, and
• at least one of conditions given by
• t1<t2
• Φ1>Φ2
• is satisfied when a ray connecting an exit pupil center of said projection optical system and a center of said reflection type display element is defined as a reference axis ray, in a plane including the reference axis ray, a ray of the image light having a maximum optical path length when the image light passes through at least a portion of the illumination optical system is represented by r1 and a ray of the image light having a minimum optical path length when the image light passes through at least a portion of the illumination optical systm is represented by r2, optical path lengths of the rays r1 and r2 in said second optical member are respectively represented by t1 and t2, and optical powers exerted on the rays r1 and r2 by said second optical member are respectively represented by Φ1 and Φ2.