Patent ID: 6836369
Filing Date: 2004-12-28
Classification: G02B

Abstract:
A head-up display for displaying picture information viewed as a virtual image from a view point, said virtual image is formed by reflecting the picture information projected from an optical unit, the optical unit comprises a display device which emits light of a plurality of wavelength-bands for displaying said picture information and a prism which is located on a light path between said display device and said view point, wherein;a first position at which light of a first wavelength-band among said a plurality of wavelength-bands is emitted and a second position which light of a second wavelength-band among said a plurality of wavelength-bands is emitted are made different from each other in the picture information formed on said display device by a distance d expressed as follows, d=L1Ã—|&phgr;i1âˆ’&phgr;i2|+L2Ã—|&phgr;o1âˆ’&phgr;o2|Ã—(cos &phgr;i1/cos &phgr;o1) and further|&phgr;o1âˆ’&phgr;o2| is within a permissible range; where L1 denotes the length of the light path between said display device and said prism, L2 denotes the length of the light path between said prism and said view point, &phgr;i1 denotes the angle of incidence at which a light of a center wavelength &lgr;1 in said first wavelength-band incidents onto said prism, &phgr;o1 denotes the angle of emergence at which the light emerges from said prism, &phgr;i2 denotes the angle of incidence at which a light having a center wavelength &lgr;2 in said second wavelength-band incidents onto said prism, and &phgr;o2 denotes the angle of emergence at which the light emerges from said prism.