Koninklijke Philips Corporation N.v.

Gte Laboratories Incorporated

Philips Electronics North America Corporation

Osram Sylvania Inc.

Koninklijke Phillips Electronics N.v.

Jerry Martin Kramer

Walter Peter Lapatovich

Babar Ali Khan

George C Wei

Paul O Haugsjaa

Ronald D Pinker

David A Cammack

John Walsh

Joseph M Proud

William H McNeill

Joseph E Lester

Vivek Mehrotra

Ronald Hans Van Der Voort

Hendrik Anton Van Esveld

Jerzy Janczak

Donald H Baird

A method and device for arc straightening in an HID lamp, the method comprising the steps of: determining and selecting a frequency signal or a frequency sweep signal that produces arc straightening for an HID lamp; and exciting an arc straightening acoustic mode in conjunction with a carrier frequency signal. In a preferred embodiment, the exciting step comprises amplitude modulating the carrier frequency signal with either the frequency signal or the frequency sweep signal which corresponds to the power frequencies for arc straightening. In a further embodiment, the exciting step comprises summing the carrier frequency signal with a second frequency signal or second frequency sweep signal to obtain a difference power frequency or power frequencies which excite an arc straightening acoustic mode.

Use of arc straightening in HID lamps operated at VHF frequencies

A method and structure for substantially overcome vertical segregation in HID lamps, the method comprising the steps of: determining and selecting a frequency sweep signal to produce arc straightening and a fixed frequency signal for exciting a second longitudinal acoustic mode; and exciting in conjunction with a carrier frequency an arc straightening acoustic mode together with a second longitudinal acoustic mode excitation. In a preferred embodiment, the exciting step comprises amplitude modulating the carrier frequency signal with a sum of the frequency sweep signal and the fixed frequency signal.

Reducing vertical segregation in a HID lamp operated at VHF frequencies using simultaneous arc straightening and color mixing

A method and ballast for driving a high intensity discharge (HID) lamp include generating a very high frequency driving signal for the HID lamp, generating a low frequency modulating signal, amplitude modulating the driving signal with the modulating signal at a predetermined low initial modulation level, measuring a lamp voltage across the HID lamp, determining a standard deviation of the lamp voltage, comparing the standard deviation with a predetermined minimum level, if the standard deviation is above the predetermined minimum level, incrementally increasing the modulation level and repeating the amplitude modulating step, the measuring step, the determining step and the comparing step, and if the standard deviation is below the predetermined minimum level, maintaining the amplitude modulation at the determined level.

High frequency electronic ballast

An apparatus and method for obtaining short-term color stability in an HID lamp, the apparatus comprising in a first embodiment a high intensity discharge lamp with a discharge vessel and electrodes; with a filling within the discharge vessel containing a metal halide dose of at least 20 mg/cc, where volume is defined as the volume of the main cylindrical section of the discharge vessel. In a preferred embodiment, the filling within the discharge vessel contains Hg of at least 20 mg/cc, where volume is defined as the volume of the main cylindrical section of the discharge vessel. In a yet further aspect, the resulting color temperature is stabilized independent of the shape and frequency of the current and voltage waveforms that drive the HID lamp.

Stabilizing short-term color temperature in a ceramic high intensity discharge lamp

Stable illumination of uniform color and reduced sensitivity to lamp orientation are achieved by driving a high-intensity discharge (HID) lamp with a carrier signal alternated between two VHF frequencies at a modulation rate approximately equal the second longitudinal frequency of the lamp, and feeding the signal through a filter having an inverse amplitude relationship to carrier frequency, to produce an input signal to the lamp that is amplitude modulated in an inverse relationship to the change in carrier frequency at a modulation rate approximately equal to the second longitudinal resonance of the lamp.

Color mixing in HID lamp at VHF frequencies

A method and apparatus for determining which power frequencies applied to a high-intensity discharge lamp cause arc instabilities therein. In one embodiment, the method comprises the steps of providing a current signal that periodically sweeps through a plurality of frequencies during a sweep time period, amplifying the current signal, inputting the amplified current signal into a high intensity discharge lamp so as to effect application of power frequencies to the lamp, determining the power frequencies of the current signal that cause arc instabilities in the high intensity discharge lamp, and determining the minimum power level of the arc instability-producing power frequencies required to cause arc instabilities. In one embodiment, the apparatus comprises a signal generating device that produces a current signal that periodically sweeps through a plurality of frequencies during a sweep time period, an amplifier for amplifying the current signal, means for inputting the amplified current signal into a high intensity discharge lamp so as to effect the application of power frequencies to the lamp, and a signal processing device for determining which of the power frequencies applied to the lamp cause arc instability and the minimum power level of these power frequencies required to cause arc instabilities.

Method and apparatus for determining power frequencies that cause arc instabilities in discharge lamps

Power source systems implementing methods for reducing vertical segregation (color mixing) in a long and thin high intensity discharge lamp are disclosed. Each system provides a current frequency signal to the lamp that excites an azimuthal acoustic and longitudinal acoustic combination mode of the lamp whereby color mixing within the lamp can be achieved. Each system further adjusts the current frequency signal as needed to stabilize color mixing within the lamp.

Method and system for exciting an azimuthal acoustic and longitudinal acoustic combination mode

In a power source system, a method for providing color mixing in a high intensity discharge (HID) lamp comprises the steps of providing a swept frequency signal having a sweeping frequency ranging between a first lower frequency value and a second higher frequency value, within a specified period. An amplitude modulation signal is also provided having an adjustable frequency value and an adjustable modulation index. As a result the sweeping frequency signal is modulated by said amplitude modulation signal. The frequency of the amplitude modulation signal is adjusted until a maximum lamp voltage is detected. Thereafter, the system operates with a modulating frequency that yields the maximum lamp voltage so as to substantially eliminate color segregation in the lamp.

System and method for determining the frequency of longitudinal mode required for color mixing in a discharge lamp

An apparatus for reducing vertical segregation of a discharge lamp. A current/voltage input sweeps through a frequency range between the first azimuthal acoustic resonance mode and a first radial acoustic resonance mode of the discharge lamp. The current/voltage input is subsequently amplitude modulated. Alternatively, without amplitude modulation, the current/voltage input sweeps through the frequency range for a first portion of the period, and then for a second portion of the period drops to a relatively constant frequency.

Reduction of vertical segregation in a discharge lamp

A high pressure gas discharge lamp and the method of making same utilizing integrated circuit fabrication techniques. The lamp is manufactured from heat and pressure resistant planar substrates in which cavities are etched, by integrated circuit manufacturing techniques, so as to provide a cavity forming the gas discharge tube. Electrodes are deposited in the cavity. The cavity is filled with gas discharge materials such as mercury vapor, sodium vapor or metal halide. The substrates are bonded together and channels may be etched in the substrate so as to provide a means for connection to the electrodes. Lamps having ignition enhancing and hot restrike features, as well as single-sided electrodes, are disclosed.

Gas discharge lamps fabricated by micromachined transparent substrates

An arc tube for an electrodeless metal halide discharge lamp has an arc chamber fabricated from a material selected from the group consisting of magnesia-doped polycrystalline alumina, silicon dioxide doped polycrystalline alumina and monocrystalline alumina. The arc chamber is tubular and has at least one end and has a given outside diameter. At least one end cap closes the at least one end of the arc chamber, the end cap being formed from magnesia-doped polycrystalline alumina and comprising a substantially cup-shaped member having an inside diameter which is sealed to the outside diameter of the arc chamber by a shrink-fit.

Arc tube for electrodeless lamp

An arc tube for an electrodeless metal halide discharge lamp has an arc chamber fabricated from a material selected from the group consisting of magnesia-doped polycrystalline alumina, silicon dioxide doped polycrystalline alumina and mono-crystalline alumina. The arc chamber is tubular and has at least one end and has a given outside diameter. At least one end cap closes the at least one end of the arc chamber, the end cap being formed from magnesia-doped polycrystalline alumina and comprising a substantially cup-shaped member having an inside diameter which is sealed to the outside diameter of the arc chamber by a shrink-fit.

A gas discharge display and the method of making same utilizing integrated circuit fabrication techniques. The display is manufactured from heat and pressure resistant planar substrates in which cavities are etched, by integrated circuit manufacturing techniques, so as to provide individual pixels. Orthogonal electrodes are deposited on the substrates and extend into the cavities. The cavities are filled with gas discharge materials, such as plasma, upon energization of the electrodes the individual cavities forming the pixels may be individually activated.

Gas discharge displays and methodology for fabricating same by

This invention teaches a novel high pressure electric discharge lamp which has the desired properties of high efficacy, good color rendering, and a warm color temperature. These desired properties are attained by utilizing as fills the rare earth iodides in conjunction with calcium halides and, or sodium halides. Efficient visible emission from the rare earth atomic and molecular fragments in the discharge is combined with the red emission from calcium monohalide to provide an efficient, warm source.

Rare earth halide light source with enhanced red emission

A laser device with a discharge tube forming a closed envelope with cylindrical end portions connected by an elongated constricted center portion and having external electrodes at the end portions, fed from a source of short pulses with a width measured in nanoseconds, capacity coupled to the discharge plasma. The discharge plasma may include metal vapor, a metal halide, including mercury halide, and internal electrodes may be included in the closed envelope but coupled to the external electrodes by capacity coupling so as to avoid any connections from electrodes passing through the glass or fused silica envelope.

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Yorktown Heights, NY, United States of America

Jerry Martin Kramer