Discharge lamp lighting circuit
US6583587B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 2002 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | Feb 25, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A discharge lamp lighting circuit adapted to control a transient power corresponding to a cooling condition or a light-out time of a discharge lamp without using a capacitor or storage device having a large capacity, thereby reducing a cost and a size. Power control in a steady state of a discharge lamp is carried out in response to a detection signal for a voltage and a current in the discharge lamp, and a power to be transiently applied to the discharge lamp is controlled before a transition to the power control. The power to be transiently applied is set to be higher than the power in the steady state, thereby promoting light emission of the discharge lamp. An increment in the transient applied power which exceeds the power in the steady state is specified corresponding to a voltage applied to the discharge lamp, a variation in the voltage and a time elapsed from a time that the discharge lamp is lighted up or a start of an operation of a lighting circuit. More specifically, a dedicated circuit for detecting the light-out time of the discharge lamp is eliminated to utilize only detection information required for the power control of the discharge lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.