Light-emitting diodes in displays with direct-lit backlight units
US10613389B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 2019 |
| Grant date | Apr 7, 2020 |
| Priority date | — |
| Expiry date | Mar 6, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/882
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a backlight unit. The backlight unit may include a printed circuit board, a plurality of light-emitting diodes mounted on the printed circuit board, at least one light spreading layer formed over the printed circuit board that spreads light received from the plurality of light-emitting diodes, a partially reflective layer formed over the at least one light spreading layer, a color conversion layer formed over the partially reflective layer, a collimating layer formed over the color conversion layer, a brightness enhancement film formed over the collimating layer, and a diffuser formed over the brightness enhancement film. The at least one light spreading layer may include two light spreading layers with elongated protrusions that are rotated relative to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.