Head-up display systems
US4993788A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 1990 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | Feb 9, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0165
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a head-up display system of the kind utilizing a holographic combiner (17) constructed to operate at a relatively large off-axis angle and an aberration compensating optical arrangement (19) in the path between an object surface (21) at which display data originates and the combiner, the light rays from the optical arrangement are redirected upwardly onto the combiner via an arrangement (25) comprising an upper optical surface (29) having both light-reflective and light-transmissive properties and a lower fully reflective optical surface (27), the two surfaces defining a space (S) forwardly tapering in the direction of ray propagation from the object surface. In operation, rays from the object surface are reflected first at the lower surface and then reflected, in part, at the upper surface back to the lower surface where they are again reflected to the upper surface for transmission therethrough to the combiner for reflection thereby to an observer. The arrangement makes available more space for a secondary display arrangement (45) below the combiner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.