OPTICAL MODULE FOR AUGMENTED REALITY DEVICE BASED ON MODIFIED STRUCTURE OF LIGHT GUIDE PLATES WITH DIFFRACTIVE OPTICAL ELEMENTS Russian patent published in 2023 - IPC F21V8/00 G02B27/01 

FIELD: optical displays and devices.

SUBSTANCE: optical displays and devices that form dynamic and static images. Invention is related to holographic translucent displays that generate multicolour information for the observer’s pupil against the background of the surrounding environment. An optical module for an augmented reality device based on a modified structure of light guide plates with diffractive optical elements, contains: a micromirror DLP display; a block of LED RGB radiation sources for illuminating the micromirrors of a DLP display and obtaining a colour image, made in form of three separate LED RGB radiation sources or three LED RGB radiation sources located on one site; an optical backlight system for the DLP display to combine the radiation of LED RGB radiation sources and ensure uniform brightness of the backlight of the DLP display; electronic control unit, synchronization and power supply of the micromirror DLP display and LED RGB radiation sources; a DLP projector with a collimating lens installed after the DLP display, wherein the collimating lens has an extended exit pupil that coincides with at least one of two input areas on light guide plates with diffractive optical elements; and two light guide plates with diffractive optical elements for outputting an image collimated by a collimating lens from a micromirror DLP display. Moreover, each light guide plate operates in its own region of the spectrum, namely: blue-green and red-green. Each light guide plate includes one output diffractive optical element and two intermediate diffractive optical elements, in the area of overlapping of which an intermodulation structure is formed, on which radiation diffracts along the symmetry axis of the light guide plate and enters the central region of the output diffractive optical element, and on each light guide plate, these diffractive optical elements have the same calculated period - 380 nm and 520 nm. Additionally, a mirror coating is applied to each light guide plate on the opposite part of the radiation input region.

EFFECT: improvement of the optical module for an augmented reality device based on a modified structure of light guide plates with RED to reduce the overall dimensions of the device as a whole, increase the working angular field, ensure uniform brightness of the output image within the entire exit pupil, and increase the efficiency of radiation input into the plate.

3 cl, 7 dwg