International Business Machines Corporation

Rainbow Displays, Inc.

Jrs Technology Inc.

Technical Consumer Products, Inc.

Jrs Technology Associates, Inc.

Robert H Katyl

David W Dranchak

Robert M Murcko

J Peter Krusius

Boris Yost

Raymond G Greene

Jeffrey D Jones

James R Petrozello

Charles Gerard Woychik

Kishor V Desai

Harold Kohn

Vilakkudi G Veeraraghavan

Nelson P Franchak

Tamar A Sholtes

Oscar A Moreno

Paul William Coteus

Paul Andrew Moskowitz

Thomas Mario Cipolla

Ronald J Moore

Steven L Bard

Robert Joseph Kelleher

Edward Jay Frankoski

Scott W Knauss

Lyn Braxton Ratcliff

Che-Yu Li

Donald P Seraphim

Thomas L Miller

John R Susko

Fletcher W Chapin

Robert Sechler

Endwell

Ray G Greene

The present invention relates to an electronic ballast that energizes fluorescent lamps connected in a parallel configuration. The ballast employs a power factor correcting boost converter that can be used over a wide range of AC line voltages to provide regulated power to a self-oscillating sine wave inverter that drives the fluorescent lighting load at high frequencies. The inverter employs special networks that limit a certain type of shoot-through current, and thus improve the efficiency of the unit. Also included is a restart circuit that limits power losses during the zero lamp condition, by periodically interrupting the inverter operation when the zero lamp state is detected. To improve operation of the power factor correcting circuitry over the wide range of AC line voltages, a DC offset is added to the sampled AC voltage at the higher AC line voltages by Zener diode based coupling circuit.

Instant start electronic ballast with universal AC input voltage

The present invention features an electronic ballast for use with gas discharge lamps incorporating a microprocessor-based network controller which facilitates the direct attachment of the ballast to a local or building-wide energy management systems. The use of the inventive ballast allows the production of a lighting luminaire whose light output, power consumption, and other operational or environmental parameters can be monitored and controlled as part of the distributed building control network. A building control computer network can control lighting functions, such as power on/off and dimming. The ballast of the present invention includes provision allowing connection to a local utility so that lighting in large buildings can be cut back in times of high power demand to help balance system loading.

Electronic ballast with embedded network micro-controller

An apparatus, and a corresponding method, for chemically etching the copper foil of a copper foil-clad substrate are disclosed. Significantly, this apparatus includes fluid jet injectors which serve to produce jets of chemical etchant. These fluid jet injectors are arranged so as to simultaneously achieve a relatively high etch rate and a relatively high etch uniformity.

Apparatus, and corresponding method, for chemically etching substrates

The present invention features a tiled, flat-panel, color display that has a color-correction capability. The display is a tiled mosaic of individual display tiles, such as AMLCDs. Column and row inputs that are typically provided for a single display tile system are distributed over a plurality of display tiles. The color purity is achieved for the display by sorting the tiles into groups, matching their color coordinates, and correcting non-uniformities optically (e.g., by using a graded neutral density filter having a grading function being the inverse of the brightness distribution non-uniformities) and/or electronically. Then, each individual tile in the mosaic is color-corrected via a multiplexed, controller/driver circuit.

Flat-panel display assembled from pre-sorted tiles having matching color characteristics and color correction capability

The present invention features methods and apparatus for the correction of spatial non-uniformities in brightness that arise from materials, manufacturing, operational and lighting parameter variations in electronic color, flat-panel displays. The methods apply both to gradual non-uniformities usually found in monolithic displays as well as to abrupt variations present in displays composed of a multitude of tiles. Corrections are performed on the electronic drive signals used to control the brightness of selected display pixels. Parameters required for these corrections are acquired via brightness measurements over selected pixels and stored after suitable transformations. The stored parameters are then used to scale and/or interpolate drive signals in real time. Corrections are performed such that any remaining gradual and abrupt brightness non-uniformities fall below the detectable threshold under the intended viewing conditions. The correction methods can also be used for correcting brightness non-uniformities arising from uneven aging of the display. Apparatus for an automatic self-calibrating function is also described.

Correction methods for brightness in electronic display

The present invention features methods and apparatus for the correction of spatial non-uniformities in color only, and color and brightness combined, that arise from materials, manufacturing, and operational variations in tiled, color flat-panel displays. Such uniformities can introduce gradual or abrupt color and brightness variations in monolithic and tiled displays. Correction methods are based on control of the manufacturing and assembly process, and/or remapping of the colors of the display to match uniformity requirements of the average human observer. Correction methods can be implemented using serial and parallel versions using electronic circuits commonly used in video signal processing. Apparatus for a self-calibration method are also described.

Color correction methods for electronic displays

A system is described for remotely controlling the dimming level of ballasts for fluorescent lamps through standard two-wire AC power wiring normally used within buildings. The system makes use of a unique dimming control that creates a small positive-negative voltage asymmetry, or DC offset, and encodes this control signal onto the power lines that supply the ballasts to be dimmed. The control unit can be integrated with a wall switch as part of a variable dimming control to supply &ldquo;local&rdquo; remote control. It can be interfaced to a building control computer. A small decoding module preferably located in the lighting fixture near the ballast recovers the control signal from the applied asymmetry of the power voltage, processes it if necessary, and feeds it to the ballast. To minimize power losses in the dimming control, a DC offset of zero volts, or no asymmetry, produces full light output. For full dimming, an offset of about 15 volts is used. The resulting maximum dissipation is only a few watts when dimming up to six, 32-watt fluorescent lamps. The advantages include savings in re-wiring costs, higher power factor levels, lower harmonic distortion and lower radio frequency interference compared to other two-wire dimming methods.

Remote dimming control system for a fluorescent ballast utilizing existing building wiring

The invention features an electronic dimming ballast for use with a gas-discharge lamp. The ballast is adapted to receive a wide variety of control signals, both from sensors near the ballast or from sensors and/or controllers located away from the ballast. The ballast is constructed on a main circuit board which contains an interface into which a wide variety of daughter circuit boards may be attached so that the ballast may be customized for a particular application or system. Typical dimming input 'commands' may be from light level sensors, proximity sensors, portable, hand-held remote controllers, building energy management systems, etc. Unique interface and/or control circuitry to adapt the basic dimming ballast to these inputs is generally contained on the pluggable daughter cards.

Modular, configurable dimming ballast for a gas-discharge lamp

The present invention features a tiled, flat-panel display (FPD) that has color-matching between the tiles, which is accomplished by a direct transformation of video data through values stored in tables, and addressed by the spatial position in both the display and the input data value. One or more transformation tables are disposed proximate a graphics controller, which synchronizes, routes and controls the timing of data to data (column) drivers of the FPD. The transformation tables may be read-only or read-write memory devices. They are used to provide data representative of corrections or adjustments of color luminance on a pixel-by-pixel, or sub-pixel-by-sub-pixel basis, thus matching color of all portions of a display tile and all tiles in the FPD. This invention also describes a method of determining the values for the tables by measuring the common luminance response of the regions of the display.

Color-matching data architectures for tiled, flat-panel displays

A large inrush of electrical current flow occurs during a short interval after switch closure, when power is applied to a conventional electronic ballast commonly used for fluorescent lighting. This inrush current flows as the main filter capacitor in the ballast charges to its steady state value. For a lighting circuit that contains a multiplicity of ballasts, the combined magnitude of the inrush is potentially large enough to cause contact failure of the switching device due to arcing and contact welding. The invention features a circuit for limiting inrush current having a current-limiting resistor that is active for a brief interval during startup. The resistor is subsequently bypassed from the principal current path by a switching transistor. The transistor is controlled by electrical signals normally present in conventional electronic ballasts. The advantage of the inventive circuitry is the use of only two inexpensive components to accomplish inrush current protection.

Inrush protection circuit

The present invention features an integrated, electronic fluorescent ballast fixture which includes an electronic ballast packaged with a set of fluorescent lamp connectors into an integral fixture. The fixture has a circuit board that selectably supports up to four fluorescent lamps. The housing of the fixture id configured to receive a number of lamp connectors. The connectors are electrically, connected to the circuit board use wire and poke-in type connectors. When used with conventional, straight fluorescent lamps, a second set of sockets at the far end of the lamps are also connected to the circuit board using wires received in poke-in connector on the circuit board. The integrated ballast package also works with U-shaped lamps. The housing of the fixture is shaped to accommodate projecting electronic ballast components attached to the circuit board. The transformers and transistors of the circuit board may be thermally sinked, so that their heat is carried to the housing by thermally conductive means. The housing consists of two halves that are assembled together with snap-in action latches, making the fixture quickly and easily fabricated. The ballast fixture can be used with a wide variety of light fixtures because of its modularity, affording a high degree of universality.

Ballast fixture for fluorescent lighting

The present invention features an electronic fluorescent lighting ballast which provides a way to transmit data by modulating the light that is emitted from lamps in a luminaire. The modulation occurs at a sufficiently high frequency, so that it is imperceptible in the range of human vision. Data can be represented in the emitted light by frequency-, phase- or amplitude-modulation. Communication methods can be either simplex or duplex. In the preferred embodiment, a simple modification of the base circuit of a typical, Class D, bipolar, push-pull inverter permits frequency- or phase-modulation of the inverter waveform. This causes modulation of the emitted light from the lamps of the luminaire. The transmission of data through an otherwise conventional lighting luminaire is desirable for many commercial applications. One example of its usage is in the transmission of audio or digital information in a grocery or department store from a centralized computer to display units on store shelves. Another example of its usage is in the transmission of audio or digital information from a central computer to various fixed or portable display terminals in an airport, providing arrival and departure information.

Fluorescent light ballast with information transmission circuitry

The present invention features a tiled, flat-panel, mosaic display with a luminance-correcting capability and having a seamlessness characteristic. Column and row inputs that are typically provided for a single flat panel are distributed over a number of tiles. The display is fabricated by sorting the tiles into groups, and matching their color coordinates prior to assembly. After assembly, measurements of the luminance of the display are processed to generate correction data, which is compressed into a reduced set of coefficients. A processor, located between a video controller and the display drivers for each of the tiles, has a memory containing these interpolation coefficients for correcting luminance in the tiles. A multiplicity of processing units is connected to the video controller and the processor for performing video correction in real time.

Tiled, flat-panel displays with luminance-correcting capability

The present invention features a tiled, substantially flat, panel display having the characteristic of visually imperceptible seams between the tiles for the intended viewing conditions, which include the perception thresholds of the human eye, the view distance, the display brightness and the level of the ambient light. The panel consists of an image source plane having spaced-apart pixels containing light-transmitting elements comprising single or multiple lightvalves. These lightvalves transmit monochromatic light, or primary color light spectra, for example, red, green and blue, in gray-scale and color displays, respectively. Each of the pixels is located along the image source plane at a uniform pitch greater than approximately 0.2 mm. Many adjacently-situated tiles are located in a plane in proximity to the image source plane. Secondary light rays can be controlled via light shields, aperture plates, masks and optical elements. The view angles of the tiled display may be further enhanced by using dispersive, optical elements such as microlens arrays. If desired, the brightness of the tiled display can be enhanced by increasing the backlight intensity or the collection of light by using optical, focusing elements such as microlens arrays.

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Vestal, NY, United States of America

Robert H Katyl