Abstract: The present disclosure relates to an optical device of a projector. More specifically, the present disclosure relates to an optical device including a beam splitter which reflects a light beam of a display panel unit and transmits a light beam sensing an image of the screen, or transmits a light beam of the display panel unit and reflects a light beam sensing the image of the screen.

Abstract: An augmented reality display device includes a micro-display; a relay lens array configured to be disposed at the rear stage of the micro-display and having a combination of two or more spherical or aspherical lenses; a combiner configured to be disposed at the rear stage of the relay lens array to project laterally an image light emitted from the relay lens array to a substrate to be described later and implement an ultra-short throw image using together with the relay lens array; a transparent or translucent substrate configured to form an image by projecting the image light transmitted from the combiner on the substrate; and a coating or film configured to be attached to one surface of a component part of the relay lens array, the combiner or the substrate so as to reflect, penetrate or refract the image light transmitted from the micro display.

Abstract: An ultra-short throw projector device includes a lens system. The lens system includes a first lens group configured to form a first intermediate image from an incident display image; a second lens group configured to form a second intermediate image from the first intermediate image; an aperture configured to be disposed on a point where the first intermediate image is formed between the first lens group and the second lens group; a reflection mirror configured to reflect and magnify the second intermediate image and form an image on a screen; and a light path changing prism configured to change a light path in the vertical direction or other directions, the prism being disposed at a point on the light path of the lens system, at least one of an incident surface and a refracting surface being an aspherical surface or a freeform surface.