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

Claim 17:
18. A head-up display for a vehicle having a window, the head-up display comprising:
a first picture-generating surface arranged to output a first picture component and a second picture-generating surface arranged to output a second picture component;
a projection engine arranged to receive the picture components output by the picture generating surfaces and project the pictures components 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 and reflect light of the first picture component and to receive and transmit 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 and reflect light of the first picture component reflected by the first polarisation-selective reflective surface, and to receive and reflect light of the second picture component transmitted by the first polarisation-selective surface,
wherein the first picture-generating surface is a first optical distance from the second reflective surface and the second picture-generating surface is a second optical distance from the second reflective surface, the second optical distance being substantially different from the first optical distance.