Northrop Grumman Systems Corporation

Westinghouse Norden Systems

Russell A Budzilek

Richard R Swatson

Dominic L Monarchie

Thomas J Rebeschi

Dominick L Monarchie

Myroslaw Podoba

Elliot Schlam

William L Nighan

Elliott Schlam

Mohan L Kapoor

Fred A Otter

An electroluminescent display having reversible polarity and a method for reducing latent images in the electroluminescent panel is provided. The electroluminescent display includes a waveform generator for supplying voltage pulses to illuminate pixels within the electroluminescent panel. The electroluminescent display according to the invention periodically reverses the polarity of the voltage pulses to reduce latent images in the electroluminescent panel. The electroluminescent display preferably utilizes an asymmetrical drive scheme to provide a brighter electroluminescent display.

Electroluminescent display having reversible voltage polarity

A relatively low cost, portable, low complexity, low power helmet mounted display using an electroluminescent display and associated drive circuitry configured and interconnected to take advantage of our ability to provide a -180 V and +240 V output to a row driver from a single -180 V and an already existing +60 V Supply, thus eliminating size, weight and expense of supplying a separate 240 V power supply. The +60 V power supply is already supplying the +60 V to the column driver circuitry. Also included is a column driver with a direct analog interface with an input buffer, the buffer including a polarity inverter and an adder for selectively inverting the external analog signal and adding a DC voltage.

High performance, low cost helmet mounted display

A thin film electroluminescent display panel is driven with either a symmetric or asymmetric drive scheme which includes at least one equalizing voltage pulse per write cycle to remove carriers trapped at the interfaces of dielectric layers and phosphor layer in order to stabilize the charge of each display panel pixel. The present invention reduces the smearing, latent image and pseudo persistence problems caused by carriers being retained and accumulated at the dielectric and phosphor layer interfaces.

Increased brightness drive system for an electroluminescent display panel

A method and apparatus for providing a column driver circuit for an electroluminescent display panel including a column driver with a column driver including a direct analog interface with an input buffer with an input for accepting an external analog signal and an output for outputting an analog signal for said electroluminescent display panel. The buffer includes a polarity inverter and an adder for selectively inverting the external analog signal and adding a DC voltage. The column driver further includes an output demultiplexer, a plurality of sample and hold circuits, and an output driver employing negative feedback techniques for comparing the feedback signal to a preselected external variable voltage and selecting the appropriate drive signal.

Analog video input flat panel display interface

A display system (25) includes an enhanced specularity multi-layer thin film electroluminescent (TFEL) panel (26) and circular polarizer filter (27) which combine to provide a high contrast TFEL display. The enhanced specularity is obtained by increasing the rate the phosphor layer of the panel is deposited which results in a smoother, more specular surface. The increased specularity of the panel (26) provides a darker display background, and therefore higher contrast.

High contrast TFEL display in which light from the transparent phosphor

An AC thin film electroluminescent display panel includes a metal assist structure formed on and in electrical contact over each transparent electrode, and light absorbing darkened rear electrodes which combine to provide a sunlight viewable display panel.

Sunlight viewable thin film electroluminscent display having darkened

An AC thin film electroluminescent display panel includes a metal assist structure formed on and in electrical contact over each transparent electrode, and a graded layer of light absorbing dark material which combine to provide a sunlight viewable display panel.

Sunlight viewable thin film electroluminescent display having a graded

A multi-color TFEL display includes a low ohm metal assist structure in electrical contact with the transparent electrodes to improve display brightness, and a light absorbing dark layer to increase display contrast.

Color thin film electroluminescent display

An AC thin film electroluminescent display panel includes a metal assist structure formed on and in electrical contact over each transparent electrode, and a light absorbing dark layer which combine to provide a sunlight viewable display panel.

Growing community of inventors

Bridgeport, CT, United States of America

Russell A Budzilek