No longer in the dark when calling a cab

Computer Cab controls a fleet of 2500 London taxis. A service offered by the company to frequent users is an international account card system, called Cabcharge. This enables passengers travelling to a destination and unable to book a return journey due to unknown finishing time to hail a passing cab and use their Cabcharge card to make the return journey on an account basis.

During daylight a small ensign on the front of the windscreen was clearly visible and customers were able to identify cabs accepting the card. After dark it was a different matter.

The obvious answer was to find a way to illuminate the existing windscreen ensign. Thoughts of using cold cathode fluorescent lighting (CCFL) were ruled out as too bulky, and presenting a hazard to the driver during emergency braking. The solution was to use thin laminar (typically 0.3mm) Electroluminescent (EL) lighting, which is constructed using phosphor particles which emit light when an AC current is applied.

A specification for the illuminated sign was prepared for Danielson, who was able to produce a solution which matched the cab company’s needs.

The laminar sign was constructed using a thin white EL lamp onto which the Cabcharge logo was printed. This could be mounted inside the windscreen using an adhesive applied during manufacture. Special inks were printed onto the lamp to replicate the corporate white and yellow text on a soft blue background.

The sign is wired into the existing headlight circuitry via a DC/AC inverter.

Danielson Tel: 01296 319000