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US 2006/0132044 A1Published application
Discharge lamp lighting device and lighting system
AssigneeToshiba Lighting & Technology Corporation
InventorsYuuji Takahashi, Kazutoshi Mita, Masahiko Kamata
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Abstract
When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.
Claims18
A discharge lamp lighting device, comprising:
- a high-frequency generating circuit which outputs high-frequency voltage;
- a discharge lamp having a pair of filament electrodes, the discharge lamp being lighted by the high-frequency voltage applied across the filament electrodes;
- a current detector detecting preheat current which flows the filament electrodes of the discharge lamp;
- a voltage detector which detects voltage generated in either one filament electrode of the pair of filament electrodes;
- and
- a controller which computes impedance of either one of the filament electrodes from the preheat current detected by the current detector and the detecting voltage of the voltage detector, and controls to preheat and light the discharge lamp in accordance with the computed impedance.
3 more elements
A lighting system, comprising:
- a host lighting apparatus which has a first discharge lamp having a pair of filament electrodes and has the first discharge lamp lighting device to preheat and light the first discharge lamp;
- one or more second lighting apparatus which has a second discharge lamp having a pair of filament electrodes and has a second discharge lamp lighting device to preheat and light the second discharge lamp;
- and
- a control section which executes switching from preheating to lighting of each of the discharge lamps when all the impedances of each filament electrode in each of the discharge lamps have reached the preliminarily defined settings.
1 more element
Dependencies are inferred from the claim text.