Discharge lamp ballast and projector
US7622869B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 2004 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | Nov 3, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A DC-DC converter 111 with a switching element Q11 changes a supply of power to a HID lamp DL1. On/off of the element Q11 is controlled with a control circuit 13. The circuit 13 controls an on/off state of the element Q11 with constant lamp power control on stable operation of the lamp. The circuit 13 controls the on/off state of the element Q11 so as to provide the lamp with lamp power larger than lamp power by the constant lamp power control based on high power control for a period of time that the lamp is on. It is possible to keep temperature of electrodes and within a bulb of the lamp in a proper state through simple control, and to prevent flicker generation and electrode degradation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.