Discharge lamp driving device, projector, and discharge lamp driving method
US9915862B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 2017 |
| Grant date | Mar 13, 2018 |
| Priority date | — |
| Expiry date | Jan 17, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a discharge lamp driving device, a mixed period is provided, in which a first period in which an alternating current is supplied and a second period in which a direct current is supplied are alternately repeated and a third period alternately including a first direct current period and a second direct current period in which a direct current having a polarity opposite to a polarity of the direct current in the first direct current period is supplied. Length of the second direct current period is smaller than 0.5 ms. A total of lengths of the first direct current periods in the third period is larger than length of the second period. The third period is not provided at least when the inter-electrode voltage is smaller than a first predetermined value or when a cumulative lighting time of the discharge lamp is smaller than a second predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.