Display apparatus for providing expanded viewing window

A display apparatus comprising:

• a light guide plate comprising an input coupler and an output coupler;
• and
• an image providing apparatus configured to provide a plurality of images traveling in different directions to the input coupler,
• wherein the image providing apparatus comprises:
• a spatial light modulator facing the input coupler and comprising a plurality of display regions configured to provide the plurality of images to the input coupler;
• and
• a light source configured to provide coherent illumination light to the spatial light modulator,
• wherein the spatial light modulator is provided such that each display region of the plurality of display regions is configured to provide a respective image to the input coupler, each respective image being formed by a different respective diffraction order,
• wherein the input coupler comprises a first sub input coupler, a second sub input coupler, and a third sub input coupler configured to propagate an image provided from the image providing apparatus at different angles in the light guide plate,
• wherein the plurality of display regions of the spatial light modulator comprises a first display region, a second display region, and a third display region corresponding to the first sub input coupler, the second sub input coupler, and the third sub input coupler, respectively, and
• wherein the first display region is configured such that a first image is obliquely incident on the first sub input coupler from the first display region, the second display region is configured such that a second image is perpendicularly incident on the second sub input coupler from the second display region, and the third display region is configured such that a third image is obliquely incident on the third sub input coupler.