Planar Systems Inc is betting on electroluminescent technology for its flat panels, in which the elements consist of transparent conductiive electrodes separated by a dielectric containing a luminescent phosphor that glows when a voltage is applied. It is brighter and has a wider viewing angle than liquid crystal, but the disadvantage has been seen as limited lifespan for the phosphors, which dim with age. Planar, of Beaverton, Oregon has launched its first electroluminescent displays, with a full colour 320 by 256 pixel red-green-blue format panel designed to replace a 5 cathode ray tube, and a 10.5 diagonal 640 by 480 pixel format multi-colour red-green-yellow display designed to provide a cost competitive VGA alternative to full colour liquid crystal displays. Both sample in the fourth quarter with production volumes in 1995. The company’s secret is a proprietary blue phosphor material and a ‘unique’ device structure for full colour. It makes extensive use of chip-on-glass fabrication techniques where the integrated driver circuits are mounted directly on the glass substrate, which is claimed to give higher reliability, lower cost and a slimmer package than existing flat panels. Planar’s multi-colour product is for users needing limited range of colour capability but requiring the environmental, reliability, response time and viewing performance advantages of electroluminescence at a lower price than liquid crystal displays – industrial, medical, and test applications where the need is to differentiate information in rugged applications. The VGA multi-colour panel is the first from Planar to use a high density 0.14mm tape automated bonding interconnect system with a proprietary 160-output driver integrated circuit, it noted.
