Patent ID: 7564630

Claim:
A scanning type image display apparatus comprising: a scanning unit which two-dimensionally scans a light flux; a first optical system which introduces a light flux from a light source to the scanning unit; a second optical system which converges the light flux from the scanning unit; a diffractive optical element which receives the converged light flux from the second optical system; and an ocular optical system which introduces the light flux from the diffractive optical element to an eye of an observer, wherein, when two directions orthogonal to each other in diametral directions of the light flux from the second optical system are a first direction and a second direction, the diffractive optical element has a function of increasing divergent angles of an emerging light flux from the diffractive optical element in the first and second directions as compared with convergent angles of an incident light flux entering the diffractive optical element in the first and second directions and a function of increasing the divergent angle of the emerging light flux in the first direction as compared with the divergent angle thereof in the second direction, and wherein the following condition is satisfied: FovH/FovV<φH/φV <(φ+5)/(φ× FovV/FovH ) where φH represents a width of the emerging light flux from the diffractive optical element in the first direction, φV represents a width of the emerging light flux in the second direction, FovV represents a display view angle of the apparatus in the first direction, and FovH represents a display view angle of the apparatus in the second direction.