Patent ID: 11480722

Abstract:
This invention relates to an optical expander device with its display device, and a method of light output and image display, including a waveguide plate, the first optical diffractive in-coupling element, the first retrieval unit, the second retrieval unit, the second optical diffractive expander element, the third optical diffractive expander element, and the fourth optical diffractive out-coupling element. The fourth optical diffractive out-coupling element forms part of the first output light (OB4), by diffracting guided light, the third retrieval light (B3a), and the fourth retrieval light (B4a) to the same direction; simultaneously, the fourth optical diffractive out-coupling element diffracts the first direct-through light (B1b) and the second direct-through light (B2b) to the same direction, forming the other part of the first output light (OB4). This device of the present disclosure may greatly improve the uniformity of the intensity distribution of the output light.