US 7,072,085 B2 · Image combiner and image display unit

Abstract

A plate part is positioned in front of the eye of the user. An image combiner causes light from an image display element to be superimposed on light that is transmitted through the plate part and conducts this light to the eye. The light from the image display element reaches the eye after being diffracted and reflected by a reflective type HOE inside the plate part. The wavelength at which the diffraction efficiency shows a maximum value when the chief rays that are emitted from the center of the display part of the image display element are diffracted and reflected by the reflective type HOE and the wavelength at which the diffraction efficiency shows a maximum value when the chief rays that are emitted from the peripheral portions of the display part in a specified direction are diffracted and reflected by the reflective type HOE are substantially different.

Claims20

Dependent claims

An image combiner comprising a reflective type holographic optical element, wherein the image combiner superimposes light from outside on light from an image display unit that emits light having wavelength region components respectively extending before and after at least one peak wavelength, wherein:

a wavelength λo and a wavelength λy are different,
where λo is a wavelength at which a diffraction efficiency of the reflective type holographic optical element has a maximum value in the wavelength region in the vicinity of one peak wavelength for chief rays that are emitted from a center of a display part of the image display unit and diffracted by the reflective type holographic optical element, and
where λy is a wavelength at which the diffraction efficiency has a maximum value in the wavelength region in the vicinity of said one peak wavelength for chief rays that are emitted from peripheral portions of the display part and diffracted by the reflective type holographic optical element.

An image display device comprising:

an image display unit that emits light having wavelength region components respectively extending before and after at least one peak wavelength;
and
a light conducting part, which conducts light from the image display unit to an eye of a user, and which comprises a reflective type holographic optical element;
wherein:
a wavelength λo and a wavelength λy are different,
where λo is a wavelength at which a diffraction efficiency of the reflective type holographic optical element has a maximum value in the wavelength region in the vicinity of one peak wavelength for chief rays that are emitted from a center of a display part of the image display unit and diffracted by the reflective type holographic optical element, and
where λy is a wavelength at which the diffraction efficiency has a maximum value in the wavelength region in the vicinity of said one peak wavelength for chief rays that are emitted from peripheral portions of the display part and diffracted by the reflective type holographic optical element.

4 more elements

Dependencies are inferred from the claim text.

Image combiner and image display unit

Life of this patent

Image combiner and image display unit

Life of this patent

Abstract

Claims20