Patent ID: 8730581

Claim:
A head-up display system for a vehicle, the head-up display being configured for use with NVIS class B goggles, comprising: a semi-transparent combiner mirror; an image source arranged to project an image on the semi-transparent combiner mirror; an illumination unit comprising a first light source and a second light source for alternatively providing light to the image source, wherein the first light source comprises a first type of light emitting diode configured for use in daylight conditions, and wherein the second light source comprises a second type of light emitting diode configured for use during night vision conditions, the first type of light emitting diode having a dominating wavelength of emitted light of 625 nanometers and a half intensity bandwidth of 20 nanometers, the second type of light emitting diode having a dominating wavelength of emitted light of 590 nanometers and a half intensity bandwidth of 18 nanometers; and a luminance control unit arranged to adjust a brightness of at least one of the image source or the first light source or the second light source currently in operation, wherein the semi-transparent combiner mirror comprises a coating configured to superimpose the projected image onto a view of an environment in front of the vehicle by transmitting light rays from the environment and simultaneously reflecting the projected image towards eyes of an observer, wherein the coating of the semi-transparent combiner mirror is centered at a wavelength of 625 nanometers and is provided with a half intensity bandwidth of 38 nanometers of the reflection.