DISPLAY APPARATUS FOR PROVIDING AN ENLARGED DISPLAY AREA

A display apparatus for displaying a virtual image (VIMG) includes a rotating expander device (EPE) to form light beams (B,B) of output light (OUT) by expanding light beams (B,B) of input light (IN), the expander device (EPE) includes: a waveguide plate (SUB), an in-coupling element (DOE) to form first guided light (B) and second guided light (B) by coupling input light (IN) into the waveguide plate (SUB), a first out-coupling element (DOE) to form output light (OUT) by coupling the first guided light (B) out of the waveguide plate (SUB), and a second out-coupling element (DOE) to form output light (OUT) by coupling the second guided light (B) out of the waveguide plate (SUB). The in-coupling element (DOE) has a first input grating vector (V) and a second input grating vector (V), and an angle (α) between the first and second input grating vectors is between 60° and 120°.