초록 ▼

The invention relates to a slimmed-down yet high-performance image display device which comprises a decentered prism capable of internal reflection and a reflection type image display device such as a reflection-type LCD or DMD and can present bright images to an observer, and provides an image disp

The invention relates to a slimmed-down yet high-performance image display device which comprises a decentered prism capable of internal reflection and a reflection type image display device such as a reflection-type LCD or DMD and can present bright images to an observer, and provides an image display apparatus comprising a light source 5, a reflection type image display device 3, and an ocular optical system for guiding an image displayed on device 3 into an eyeball position for forming an intermediate image 4. The ocular optical system comprises a prism member 10 comprising an entrance surface 11 and two reflecting surfaces 12 and 13. In a prism, an optical path for connecting the first surface 11 with the second surface 12 intersects a reflecting optical path from the third surface 13. The ocular optical system further comprises a back-coated reflecting surface 23 between the third surface 13 and an observer's eyeball side. The first surface 11, second surface 12 and third surface 13 are located between the image display device 3 and the intermediate image 4. The second surface 12, third surface 13 and back-coated reflecting surface 23 are each formed into a rotationally asymmetric surface shape capable of imparting power to a light beam and making correction for decentration aberrations. Illumination light is incident from the third surface 13 on the image display device 3 to illuminate the same.

대표청구항 ▼

[ What we claim is:] [1.]1. An image display apparatus comprising an illumination light source, an image display device and an ocular optical system for guiding an image formed by said image display device to a position of an observer's eyeball, wherein:said ocular optical system is designed to form

[ What we claim is:] [1.]1. An image display apparatus comprising an illumination light source, an image display device and an ocular optical system for guiding an image formed by said image display device to a position of an observer's eyeball, wherein:said ocular optical system is designed to form an intermediate image for said image formed by said image display device, so that said intermediate image can be projected onto the observer's eyeball,said ocular optical system comprises at least one prism member filled therein with a medium having a refractive index of at least 1, said prism member comprising a first surface through which image-carrying light leaving said image display device enters a prism, a second surface at which a light beam incident from said first surface is reflected and a third surface at which a light beam reflected from said second surface is reflected, while an optical path for connecting said first surface with said second surface intersects a reflection optical path from said third surface,said ocular optical system further comprises at least one back-coated reflecting surface located on an optical path between said third surface and an observer's eyeball side for reflecting a light beam upon reflection at said third surface,at least said first surface, said second surface and said third surface of said prism member being positioned between said image and said intermediate image,at least one of said second surface and said third surface, and said at least one back-coated reflecting surface have each a curved surface shape capable of imparting power to a light beam, said curved surface shape being defined by a rotationally asymmetric surface shape capable of making correction for aberrations produced by decentration,said image display device is built up of a reflection type image display device for displaying an image thereon by means of reflected light, andsaid illumination light source is designed to cause illumination light beam to be incident on said reflection type image display device from said second surface or said third surface or a surface near thereto, thereby illuminating said image display device.