| abstract |
During use, a plate-form part 5 which is constructed from an optical material and which corresponds to a spectacle lens is positioned in front of the eye of the user which is disposed in the vicinity of the exit pupil P of an image combiner 1 . The combiner 1 causes light from an image display element 2 to be superimposed on light that is transmitted through the plate-form part 5 so as to pass through the thickness of the plate-form part 5 from the front of the plate-form part 5 , and conducts this light to the eye. The light from the image display element 2 reaches the eye of the user after being diffracted and reflected by a reflective type HOE 6 inside the plate-form part 5 . 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 2 are diffracted and reflected by the reflective type HOE 6 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 6 are substantially different. As a result, it is possible to improve the image quality of the display images that are obtained in cases where the center of the pupil of the eye of the user deviates from the center of the exit pupil of the image combiner. |