COHERENT LIGHTING DEVICE WITH LIGHT RECUPERATION Russian patent published in 2018 - IPC G09G3/36 G02F1/1333 

FIELD: optics.

SUBSTANCE: invention relates to optical technique. Technical result is achieved due to at least one light guide plate (LGP), LGP has two flat surfaces and has a first end and a second end opposite to the first end; one or more introductory diffraction gratings placed on one of these two surfaces, and these one or more introductory diffraction gratings are located in the region adjacent to the first end; at least one coherent light source configured to supply coherent light to the LGP through the input diffraction gratings, and the input diffraction gratings are adapted to direct the light into the LGP at the angle to ensure complete internal reflection of the light inside the LGP; one or more output diffraction gratings placed on one of these two surfaces, the output diffraction gratings are adapted to partially diffract the light incident on the output diffraction gratings from inside the LGP, outside the LGP.

EFFECT: technical result is to increase the efficiency of the backlight provided by the backlight device (BLU).

48 cl, 1 tbl, 18 dwg