High-brightness holographic waveguide display device

Abstract

The invention discloses a high-brightness holographic waveguide display device which comprises a micro display device, a collimating mirror, a waveguide, an incident coupler and an outgoing coupling member holographic grating. The incident coupler comprises a top-layer holographic grating and a bottom-layer holographic grating. The top-layer holographic grating and the outgoing coupling member holographic grating are tightly connected with two ends of the first surface of the waveguide. The bottom-layer holographic grating is closely connected with the second surface of the waveguide and is arranged below the top-layer holographic grating. The top-layer holographic grating and the bottom-layer holographic grating realize Bragg diffraction on an incident light beam and the incident light beam enters the waveguide. The incident light beam is transmitted in a total reflection manner until the light beam is diffused and output by the outgoing holographic grating. Compared with the prior art, the high-brightness holographic waveguide display device increases spectral bandwidth and improves display brightness of the holographic waveguide display device under a precondition that the peak diffraction efficiency of the holographic grating does not reduce.

Description

technical field [0001] The invention relates to a waveguide display device, in particular to a high-brightness holographic waveguide display device. Background technique [0002] The holographic waveguide display device belongs to the field of head-mounted enhancement technology, and its key technology is to replace traditional optical elements with holographic optical elements as waveguide couplers to form a wearable imaging system with high integration. [0003] In the prior art, by using a volume holographic grating as the holographic waveguide structure of the outgoing and incoming couplers, the brightness of the exit pupil of the holographic waveguide display device is too low due to the angular selectivity and wavelength selectivity of the volume holographic grating, which cannot meet the requirement of enhancement. Real system requirements for virtual image brightness. [0004] In addition, some people have proposed that the in-coupling end is a double-sided holograp...

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Problems solved by technology

[0003] In the prior art, by using a volume holographic grating as the holographic waveguide structure of the outgoing and incoming couplers, the brightness of the exit pupil of the holographic waveguide display device is too low due to the angular selectivity and wavelength selectivity of the volume holographic grating, which cannot meet the requirement of enhancement. Requirements of Realistic Systems for the Brightness of Virtual Images

[0004] In addition, some people have proposed that the in-coupling end is a double-sided holographic grating structure. This solution increases the display brightness by adding a deviation angle to the inclination angle of the in-coupling end volume holographic grating, but this method will lead to more stray light. , and when the deviation angle is large, the color crosstalk problem is more serious for color display, and the brightness gain is small, and it cannot meet the requirements of the augmented reality system for the virtual image brightness

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