06239716 is referenced by 52 patents and cites 14 patents.

An optical display device has a set of LEDs arranged in a matrix and includes control circuitry which acts as a controllable current source and as controllable voltage sources. The control circuitry enables a constant current to be applied for each LED, and respective voltages to be established accordingly. Due to the additional logic circuitry which deliver different clock pulses at different frequencies for cyclic switching of at least one LED, signals that are visible to the human eye are generated and at the same time signals that are not visible to the human eye are also generated. The signals that are not visible are digitally coded and transmitted for appropriately adapted reading devices. Thus additional information for a variety of purposes can be made available, especially in the communications and traffic area, simultaneously with the lighting up of the LEDs. This refers in particular to traffic control systems, diagnosis and monitoring. An optical display device designed in this way permits a design, for example, as a taillight, brake light, flashing indicator light and the like in a motor vehicle or with other traffic and communications means and also in equipment in production facilities while permitting favorable production at the same time due to reduced fault in assembly and ease of adjustment of the light values.

Title
Optical display device and method of operating an optical display device
Application Number
9/335418
Publication Number
6239716 (B1)
Application Date
June 17, 1999
Publication Date
May 29, 2001
Inventor
Markus Maile
Boeblingen
US
Jens Peter Seher
Stuttgart
US
Gerhard Pross
Weil im Schönbuch
US
Assignee
Hewlett Packard Company
CA, US
IPC
G08B 5/00
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