An altimeter has four display panels each being a matrix array of light-emitting diodes. An energizing unit energizes selected diodes to produce a representation of a number in each panel indicative of the value of the input. A knob on the altimeter selects input signals from a barometric source or a...http://www.google.es/patents/US4581612?utm_source=gb-gplus-sharePatente US4581612 - Display with matrix array of elements
