US 12,392,941 B2
Surface light source projection device with improved zero-order diffraction
Jun-Wen Chung, Tainan (TW); Hsu-Wen Fu, Kaohsiung (TW); and Lu-Lang Hsu, Hsinchu County (TW)
Assigned to Guangzhou Tyrafos Semiconductor Technologies Co., Ltd., Guangzhou (CN)
Filed by Guangzhou Tyrafos Semiconductor Technologies Co., Ltd., Guangzhou (CN)
Filed on Jun. 16, 2022, as Appl. No. 17/841,709.
Claims priority of application No. 111115087 (TW), filed on Apr. 20, 2022.
Prior Publication US 2023/0341598 A1, Oct. 26, 2023
Int. Cl. G02B 5/18 (2006.01); G02B 27/42 (2006.01); G01S 7/481 (2006.01)
CPC G02B 5/1866 (2013.01) [G02B 27/4272 (2013.01); G01S 7/4814 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A surface light source projection device with improved zero-order diffraction, comprising:
a diffractive optical element module, having a light incident surface and a light exit surface, and the diffractive optical element module being disposed with two micron diffraction layers, the micron diffraction layers comprising a plurality of microstructures, each of the microstructures being shaped conical, disc-shaped or any combination of the above with a circular perimeter, and the circular perimeter having a total outer diameter; and
a light exit module, for outputting a collimated light beam, the collimated light beam having an incident wavelength, wherein the collimated light beam is incident on the light incident surface of the diffractive optical element module, and wherein the diffractive optical element module outputs a diffracted light from the light exit surface after the collimated light beam has passed through the diffractive optical element module;
wherein each of the microstructures is formed with a first recess inside the circular perimeter, the first recess has a first depth and a first opening with a first outer diameter, the total outer diameter is between 5 times and 200 times the incident wavelength, and the first outer diameter is between 0.3 and 0.7 times the total outer diameter.