White LED for backlight with phosphor plates
US7682850B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2006 |
| Grant date | Mar 23, 2010 |
| Priority date | — |
| Expiry date | Jul 5, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A white light LED for use in backlighting or otherwise illuminating an LCD is described where the white light LED comprises a blue LED over which is affixed a preformed red phosphor platelet and a preformed green phosphor platelet. In one embodiment, to form a platelet, a controlled amount of phosphor powder is placed in a mold and heated under pressure to sinter the grains together. The platelet can be made very smooth on all surfaces. A UV LED may also be used in conjunction with red, green, and blue phosphor plates. The LED dies vary in color and brightness and are binned in accordance with their light output characteristics. Phosphor plates with different characteristics are matched to the binned LEDs to create white light LEDs with a consistent white point for use in backlights for liquid crystal displays.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.