Patent ID: 11947127
Assignee: ENVISICS LTD
Field: Optics (Instruments)
Classification: CPC G  B | IPC B  G

Claim 0:
1. A head-up display for a vehicle having a window, the head-up display comprising:
a picture generating unit arranged to output pictures, wherein each picture comprises a first picture component and a second picture component;
a projection engine arranged to receive the pictures output by the picture generating unit and project the pictures onto the window of the vehicle in order to form a first virtual image of the first picture component at a first virtual image distance from a viewing plane and a second virtual image of the second picture component at a second virtual image distance from the viewing plane, wherein the first virtual image distance is substantially different from the second virtual image distance, and wherein light of the first picture component is polarised in a first polarisation direction and light of the second picture component is polarised in a second polarisation direction perpendicular to the first polarisation direction,
wherein the projection engine comprises
a first polarisation-selective reflective surface arranged to receive light of the first picture component and light of the second picture component and to reflect the light of the first picture component a first optical power and to transmit the light of the second picture component; and
a second reflective surface arranged to receive light of the second picture component transmitted by the first polarization-selective mirror and to reflect the light of the second picture component transmitted by the first polarization-selective mirror with a second optical power,
the first optical power being substantially different than the second optical power.