Device for turning on high-pressure discharge lamp and lighting apparatus equipped with the device
US7432670B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 2004 |
| Grant date | Oct 7, 2008 |
| Priority date | — |
| Expiry date | Jan 1, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Even if a DC output voltage of a step-down chopper circuit (3) is lowered from a value in a non-lighted state or a no-load state due to a discharge occurring between conductors (105a) in a cable (104), the turn on detection circuit (26a) can discriminates between lighted and non-lighted states without erroneously determining such a discharge as a discharge in a discharge lamp (4). This allows an operation of the timer (29) to be continued, so that high-voltage pulses are intermittently applied to prevent continuous discharge between the conductors (105) and abnormal heat generation in the cable (104). Further, even if a discharge occurs in an outer tube of the discharge lamp (4), the turn on detection circuit (26a) never erroneously discriminates this discharge as the lighted state. Thus, the lighting device of the present invention can suppress abnormal heat generations in the components and a socket (102).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.