|Head-Up Display [HUD]
|TecHUD Overhead Unit
|Year of Manufacture:
Width (mm): 230
Height (mm): 250
Depth (mm): 650
Weight (g): 11,700
|Rack RAA14 (HUD DUs) [Mezzanine Store]
In late 1997 the Technology Enhanced Civil Head Up Display (TECHUD) programme was underway in the Company. The Department of Trade and Industry, under their Civil Aviation Research and Development (CARAD) initiative, supported a three-year collaborative research project into new technologies that have the potential to reduce the size, weight and cost of future civil HUDs. This programme, the Technology Enhanced Civil HUD (TECHUD) project, was led by GEC Marconi Avionics Ltd and included Carbon Design Partnership Ltd, Avimo Optical Imaging Ltd, Avimo Thin Film Technologies Ltd, and Central Research Laboratories Ltd (CRL). It was aimed at developing a number of building blocks such as advanced holographic optics, plastic optics, advanced optical coatings, LCD, high power backlights and composite material assemblies.
The key technologies to be studied were:
- Carbon composites to replace aluminium housings to reduce weight.
- LCDs with high intensity backlights to replace cathode ray tubes (CRTs) so as to reduce size and replace high voltage analogue circuitry with digital IC devices.
- Plastic lenses to replace glass components to reduce cost and weight.
- Improved techniques for the deposition of dielectric coatings on plastics to enhance
performance and improve system designs.
-Advanced holographic components to reduce the number of optical lens components required.
A separate demonstration was of the 'Transmission Hologram' HUD which became known simply as TECHUD. The first demonstration was surprisingly mature, but it was recognised that it would take many years before the holographic elements would be ready to consider for a design. The optical design used a prism and a single transmission hologram acted like a conventional HUD steering the image forward to the Combiner Glass in a novel way and also collimating the image. A TFOV of 30 x 20 deg and an IFOV of 30 x 15 deg was obtained. The optics developed under the TECHUD programme employed a unique diffractive element which was patented. It was essentially a multi-bounce prism block with a final lens element and diffractive surface. The Combiner was a conventional flat glass since collimation was carried out within the diffractive element. There is no relay lens system. A holographic optical element could be used as in the LANTIRN display system to put collimating power in the Combiner glass and as in TECHUD for steering the light rays. Its use for correcting aberrations in the optical system was to be developed further for the Eurofighter HUD.