Improvements in LED brightness have resulted in their use in applications that were formerly the domain of incandescent lamps. For example, LEDs can now be found in street lights, traffic signals, and automobile signal lamps.

The first LED signal lamp appeared on a passenger vehicle in 1985. In 1986 the Nissan 300ZX center high mounted stop lamp used 72 LEDs assembled on a printed circuit board. With today's LEDs, this same function can be achieved with 12 LEDs. Because of the reduction in the number of LEDs required for a particular function, LED packaging and assembly costs have also been greatly reduced. Compared to conventional incandescent automotive signal lamps, LEDs have lower power consumption, decreasing the overall system cost in today's electrically demanding vehicles.

This issue of the Hewlett-Packard Journal begins with an article about an HP technology that uses LEDs for automobile taillamps. The technology, called HP SnapLED, is a three-dimensional assembly technique that allows LEDs to be packaged into thin taillamps in such a way that they can be customized to conform to the shape of a particular vehicle. The author describes the design and manufacturing processes involved in creating the SnapLED assemblies.

Other products and technologies described in this issue include: two API libraries for creating applications to access and control OTDRs, a project that ported a UNIX^®-based product to Windows NT^®, the issues involved in integrating technical and corporate data information systems, a new approach to developing internationalized software, and two papers from HP internal engineering conferences.

C. L. Leath
Managing Editor