Full-color inclined waveguide projection display system

The invention discloses a full-color inclined waveguide projection display system which comprises a micro display screen (101), a free curved surface collimating prism (102), an oblique waveguide board (103), a coupling input grating (104) and a coupling output grating (105). Parallel incident light only enters from the left side of the waveguide surface normal line. Therefore the horizontal component of the incidence angle is a positive value constantly. Hereon the period of the coupling grating can be larger than the shortest wavelength of the incident light. The relatively long grating period can make full-color incident light in a relatively large range be coupled to a waveguide board. Compared with prior art, the full-color inclined waveguide projection display system is advantageousin that large-visual-field-angle full-color displaying is realized just through one waveguide board and the input grating and the output grating in one pair. Compared with a traditional collimating lens set, the collimating p