US Patent 12124073 Method of fabricating diffractive backlight

Fabricating a diffractive backlight employs a universal grating and selects a portion of the universal grating using a reflective island to define a grating element, a reflective diffraction grating element of the diffractive backlight including the grating element and the reflective island. A method of fabricating a diffractive backlight includes forming the universal grating, forming the reflective island, and selecting a portion of the universal grating using the reflective island to define the grating element. The method of fabricating a diffractive backlight may include forming the reflective island on a light guide surface and forming the universal grating over the reflective island. Alternatively, the method of fabricating a diffractive backlight may include forming the universal grating on the light guide surface and forming the reflective island over the universal grating.