The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 1998
Filed:
Oct. 03, 1995
Monte Rhoads, Hillsboro, OR (US);
Planar Systems, Inc., Beaverton, OR (US);
Abstract
Energizing an active matrix electroluminescent device with a generally sinusoidal illumination waveform causes the electroluminescent layer to emit light. A sinusoidal waveform minimizes the peak currents reducing the likelihood of burnouts and decreases the imposed voltages on the data lines increasing the likelihood that the high voltage transistors will function as intended. Preferably, the sinusoidal waveform is generated by using a single 12 volt power source which reduces the expense, weight and bulk of the electroluminescent device. The 12 volt power source may be used to operate an operational amplifier that receives a small sinusoidal input signal and produces a low voltage generally sinusoidal waveform that is amplified by a step-up transformer for energizing the transparent electrode layer of the device so as to cause the electroluminescent layer to emit light. Furthermore, the use of a generally low voltage operational amplifier permits the routing of a 12 volt power signal from a remote power source, such as a battery, to a head-mounted active matrix electroluminescent device, reducing safety concerns routing of high voltage signals near the body of the user.