Cold cathode lamp and lamp control circuit
OwnerRobert E. Ianniniinventor
Life of this patent
Estimating the term…
Abstract
A cold cathode gas discharge lamp unit and control circuit for controlling the light emission of the cold cathode gas discharge lamp. A lamp unit includes a dc power source and a control circuit for converting into a high frequency drive signal across the lamp wherein each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
Claims13
A control circuit for controlling the light emission of a cold cathode gas discharge lamp, comprising:
- a dc power source, and
- a control circuit for converting dc power from the dc power source into a high frequency drive signal across the lamp, wherein
- each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
A control circuit for generating a high frequency drive signal controlling the light emission of a cold cathode gas discharge lamp, comprising:
- a transformer having
- a primary winding connected from a dc power source and in series with a switching transistor, and
- a secondary winding connected across the lamp, and a drive signal timing circuit, including
- a feedback winding of the transformer connected between the base of the switching transistor and a timing control output of a resistor-capacitor ramp generator, wherein
- each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
A lighting unit, comprising:
- a cold cathode gas discharge lamp, and
- a control circuit for generating a high frequency drive signal controlling the light emission of the cold cathode gas discharge lamp, including
- a transformer having
- a primary winding connected from a dc power source and in series with a switching transistor, and
- a secondary winding connected across the lamp, and
- a drive signal timing circuit, including
- a feedback winding of the transformer connected between the base of the switching transistor and a timing control output of a resistor-capacitor ramp generator, wherein
- each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
A lighting system, comprising:
- a plurality of lighting units, each lighting unit including
- a cold cathode gas discharge lamp, and
- a control circuit for generating a high frequency drive signal controlling the light emission of the cold cathode gas discharge lamp, including
- a transformer having
- a primary winding connected from a dc power source and in series with a switching transistor, and
- a secondary winding connected across the lamp, and
- a drive signal timing circuit, including
- a feedback winding of the transformer connected between the base of the switching transistor and a timing control output of a resistor-capacitor ramp generator, wherein
- each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
A lighting unit, comprising:
- a tubular lamp housing,
- a U-shaped cold cathode gas discharge lamp mounted in the housing with all electrodes of the lamp located at a base end of the housing,
- a control circuit mounted in the base end of the housing for converting dc power from the dc power source into a high frequency drive signal across the lamp, wherein each cycle of the drive signal includes an ignition period with a signal level sufficient to initiate gas conduction, a sustaining period with a signal level sufficient to sustain gas conduction, and an off period with a signal level below the sustaining level.
Dependencies are inferred from the claim text.