Patent attributes
The present invention relates to an image display device in which a virtual image of an image display element is formed to display an image. The image display device includes a transmission type diffraction optical element (50) for diffracting exit lights from the image display element (20) and a reflection type optical element (70) having a positive optical power for reflecting the diffracted lights from the transmission type diffraction optical element (50). When the reflected lights reflected by the reflection type optical element (70) are incident again on the transmission type diffraction optical element (50), the transmission type diffraction optical element (50) diffracts the reflected lights with a diffraction efficiency lower than a diffraction efficiency for the exit lights from the image display element (20).
