Patent · US Active

Projection apparatus

US8189123B2 · kind B2 · utility

2Cited by

4References

26Claims

0Family size

Assignee

OSRAM Opto Semiconductors GmbH · DE

Inventors

Gerhard Kuhn · Altötting, DE
Moritz Engl · Nanhu, CN
Patrick Kromotis · Regensburg, DE
Stefan Grötsch · Regensburg, DE
Josef Huttner · Regensburg, DE
Mario Wanninger · Regensburg, DE
Georg Bogner · Lappersdorf, DE

Key dates

Filing date	Apr 21, 2006
Grant date	May 29, 2012
Priority date	—
Expiry date	Feb 14, 2029

Classification

Technology area (CPC H)Electricity
CPC primaryH10H20/856
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A projection apparatus is specified, comprising a light modulator having a light receiving region with a cross-sectional area to be illuminated of the size AM and a maximum acceptance angle α for incident light, and at least one light source by means of which, during its operation, a light cone is produced for illuminating said cross-sectional area of said light receiving region and which comprises a number N of LED chips having a maximum radiation angle β. At least one of the LED chips has a radiation decoupling area of the size AD. The relation 0.7·(AM·sin2(α))/(AD·sin2(β)·n2)≦N≦1.3·(AM·sin2(α))/(AD·sin2(β)·n2) applies, where n is equal to 1 or to the refractive index of a coupling medium with which the LED chips are provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.