Image display apparatus and image display system

An image display apparatus comprising:

• a light source unit;
• an image generating element configured to modulate an incident light beam and to generate an image light beam;
• a light guide member configured to propagate a light beam from the light source unit inside the light guide member and to emit as an illumination light beam part of the light beam from each of a plurality of regions on the light guide member toward the image generating element;
• an optical system configured to guide the image light beam from the image generating element to an observation side or a projection side;
• and
• a light-distribution-angle conversion element disposed between the light guide member and the image generating element and configured to convert a light distribution angle of at least one of the illumination light beam and the image light beam,
• wherein the following inequalities are satisfied:
• 0.9
• ≤
• θ2
• /
• θ1
• ≤
• 1.1
• θ2
• <
• θ3
• 0.2
• ≤
• θ3
• /
• θ4
• ≤
• 1.5
• where θ1 is a divergence angle of the light beam emitted from the light source unit, θ2 is a divergence angle of the illumination light beam emitted from the light guide member, θ3 is an divergence angle of the image light beam emitted from the light-distribution-angle conversion element, and θ4 is twice as large as a numerical aperture of the optical system.

An image display system comprising:

• an image display apparatus;
• and
• an eyepiece optical system configured to guide the image light beam from the image display apparatus to an eye of an observer,
• wherein the image display apparatus includes:
• a light source unit;
• an image generating element configured to modulate an incident light beam and to generate an image light beam;
• a light guide member configured to propagate a light beam from the light source unit inside the light guide member and to emit as an illumination light beam part of the light beam from each of a plurality of regions on the light guide member toward the image generating element;
• an optical system configured to guide the image light beam from the image generating element to an observation side or a projection side;
• and
• a light-distribution-angle conversion element disposed between the light guide member and the optical system and configured to convert a light distribution angle of the image light beam,
• wherein the following inequalities are satisfied:
• 0.9
• ≤
• θ2
• /
• θ1
• ≤
• 1.1
• θ2
• <
• θ3
• 0.2
• ≤
• θ3
• /
• θ4
• ≤
• 1.5
• where θ1 is a divergence angle of the light beam emitted from the light source unit, θ2 is a divergence angle of the illumination light beam emitted from the light guide member, θ3 is an divergence angle of the image light beam emitted from the light-distribution-angle conversion element, and θ4 is twice as large as a numerical aperture of the optical system.

An image display system comprising:

• an image display apparatus;
• and
• an eyepiece optical system configured to guide the image light beam from the image display apparatus to an eye of an observer,
• wherein the image display apparatus includes:
• a light source unit;
• an image generating element configured to modulate an incident light beam and to generate an image light beam;
• a light guide member configured to propagate a light beam from the light source unit inside the light guide member and to emit as an illumination light beam part of the light beam from each of a plurality of regions on the light guide member toward the image generating element;
• an optical system configured to guide the image light beam from the image generating element to an observation side or a projection side;
• and
• a light-distribution-angle conversion element disposed between the light guide member and the image generating element and configured to convert a light distribution angle of at least one of the illumination light beam and the image light beam,
• wherein the following inequalities are satisfied:
• 0.9
• ≤
• θ2
• /
• θ1
• ≤
• 1.1
• θ2
• <
• θ3
• 0.2
• ≤
• θ3
• /
• θ4
• ≤
• 1.5
• where θ1 is a divergence angle of the light beam emitted from the light source unit, θ2 is a divergence angle of the illumination light beam emitted from the light guide member, θ3 is an divergence angle of the image light beam emitted from the light-distribution-angle conversion element, and θ4 is twice as large as a numerical aperture of the optical system.