Patent ID: 7695144

Claim:
An optical system of a portable projector comprising: a light transmission member having first and second surfaces; a light source device for emitting light beams onto the first surface of the light transmission member based on an external image signal, so as to allow the light beams to be transmitted into the light transmission member; one or more optical elements supported on at least one of the first and second surfaces of the light transmission member for diffracting and reflecting the light beams incident from the light source device into the light transmission member and at least one scan mirror supported on one of the first and second surfaces of the light transmission member for scanning the light beams, diffracted and reflected from the optical elements, onto an external screen at the outside of the light transmission member, based on an external control signal, wherein the optical elements include: at least one light splitter supported on the first surface of the light transmission member for transmitting a specific wavelength of the light beams emitted from the light source device; a first lens placed on a surface of the light splitter facing the light source device for diffracting the light beams emitted from the light source device; and at least one second lens supported on at least one of the first and second surfaces of the light transmission member for diffracting the light beams emitted from the light splitter, to emit the diffracted light beams to the scan mirror, wherein a first surface of the first lens, on which the light beams are incident, has a grating angle for converging the light beams, and a second surface of the first lens, from which the light beams are emitted, has a grating angle for changing the path of the light beams.