Light control device
AssigneeEnvisics Ltd
InventorsAlexander Cole, Daniel Molina
Life of this patent
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Abstract
A head-up display is provided. The head-up display comprises an optical component comprising a surface arranged, during head-up display operation, in a configuration that is conducive to sunlight glare. The head-up display further comprises a reflection suppression device arranged to receive sunlight on an optical path to the surface. The reflection suppression device comprises a lattice structure. The lattice structure extends in a first direction and a second direction. The lattice structure forms a plurality of channels extending in a third direction. Each channel is defined by a respective axis having a first angle in the first direction and second angle in the second direction. The first angle is a function of the first direction.
Claims30
A method of head-up display in a vehicle, the method comprising:
- displaying a hologram of an image on a spatial light modulator;
- illuminating the hologram displayed on the spatial light modulator to form spatially modulated light encoded with the hologram;
- propagating the spatially modulated light to a scattering diffuser disposed at an image reconstruction plane of the hologram to provide a reconstructed image on the diffuser and provide the reconstructed image as an output of the scattering diffuser;
- coupling the output of the scattering diffuser into an input port of a planar waveguide pupil expander;
- replicating the reconstructed image to form an array of replicas of the reconstructed image, the array having a first direction and a second direction;
- transmitting the array of replicas of the reconstructed image through a plurality of tilted channels of a reflection suppression device disposed on top of the planar waveguide pupil expander, wherein each tilted channel of the plurality of channels is tilted from vertical by a first angle in the first direction of the array of replicas and tilted from vertical by a second angle in the second direction of the array of replicas, wherein the first angle of the tilted channels increases with distance in the first direction;
- relaying the plurality of replicas of the reconstructed image to an eye-box of the head-up display using a windscreen of the vehicle;
- and
- simultaneously with the transmitting, blocking sunlight on an optical path to the eye-box via the planar waveguide pupil expander using walls of the tilted channels.
A head-up display for a vehicle, the head-up comprising:
- a spatial light modulator arranged to display a hologram of an image;
- a light source arranged to illuminate the hologram displayed on the spatial light modulator to form spatially modulated light encoded with the hologram;
- a diffuser disposed at an image reconstruction plane of the hologram and arranged to receive the spatially modulated such that a reconstructed image is formed thereon;
- a planar waveguide pupil expander comprising:
- an input port arranged to receive the reconstructed image from the diffuser;
- and
- a pair of opposing reflective surfaces arranged to waveguide the reconstructed image therebetween by internal reflection to form a plurality of replicas of the reconstructed image for transmission to a viewing window, wherein a first surface of the pair of opposing reflective surfaces is partially transmissive thereby forming an output port for a plurality of replicas of the reconstructed image;
- wherein the first surface is arranged, during operation of the head-up display, on an optical path of sunlight from the planar waveguide pupil expander to the viewing window;
- and
- a reflection suppression device arranged on the optical path of the sunlight to the first surface of the planar waveguide pupil expander, the reflection suppression device comprising a plurality of tilted channels, wherein each tilted channel of the plurality of channels is tilted from vertical by a first angle in a first direction of the array of replicas and tilted from vertical by a second angle in a second direction of the array of replicas, wherein the first angle of the tilted channels increases with distance in the first direction.
Dependencies are inferred from the claim text.