High pressure lamp with specific amount of mercury, halogen and wall loading
US6271628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1998 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Jun 3, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high pressure mercury lamp in which formation and spreading of milky opacification in the fused silica glass forming the discharge vessel can be advantageously prevented, and thus a rapid decrease of screen illuminance prevented, when it is used as the light source of a liquid crystal projector and the like by, in a high pressure mercury lamp in which a discharge vessel of fused silica glass contains a pair of opposed tungsten electrodes, mercury in an amount that is at least equal to 0.16 mg/mm.sup.3, rare gas, and at least one halogen, and in which the wall load is at least equal to 0.8 W/mm.sup.2, the amount of mercury added being fixed in a range from 2.times.10.sup.-4 to 7.times.10.sup.-3 .mu.mole/mm.sup.3, and/or the at least one halogen being in the form of a carbonless halogen compound, and/or the average OH radical concentration in an area of a wall of the discharge vessel at a depth of 0.2 mm from an inner surface of the wall of the discharge vessel being at most 20 ppm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.