UHP lamp systems for projection applications

Abstract

Projection systems have found widespread use in conference rooms and other professional applications during the last decade and are now entering the home TV market at a considerable pace. Projectors as small as about one litre are able to deliver several thousand screen lumens and are, with a system efficacy of over 10 lm W −1 , the most efficient display systems realized today. Short arc lamps are a key component for projection systems of the highest efficiency for small-size projection displays. The introduction of the ultra high performance (UHP) lamp system by Philips in 1995 can be identified as one of the key enablers of the commercial success of projection systems. The UHP lamp concept features outstanding arc luminance, a well suited spectrum, long life and excellent lumen maintenance. For the first time it combines a very high pressure mercury discharge lamp with extremely short and stable arc gap with a regenerative chemical cycle keeping the discharge walls free from blackening, leading to lifetimes of over 10 000 h. Since the introduction of the UHP lamp system, many important new technology improvements have been realized: burner designs for higher lamp power, advanced ignition systems, miniaturized electronic drivers and innovative reflector concepts. These achievements enabled the impressive increase of projector light output, a remarkable reduction in projector size and even higher optical efficiency in projection systems during the last years. In this paper the concept of the UHP lamp system is described, followed by a discussion of the technological evolution the UHP lamp has undergone so far. Last, but not least, the important improvements of the UHP lamp system including the electronic driver and the reflector are discussed.

Visual Function in Mice with Photoreceptor Degeneration and Transgenic Expression of Channelrhodopsin 2 in Ganglion Cells

“…The intensity of the light stimuli falling onto the retina was adjusted by neutral density filters and measured by a photometer (ILT1400, detector SEL 0.33, International Light Technologies). The Philips LC5141 multimedia projector was powered by a 150 W UHP lamp (Derra et al, 2005). The emitted light was filtered by a spinning filter wheel of red, green and blue sectors, and projected by a Texas Instrument DLP chip.…”

“…Gratings or uniform fields were projected onto the screens by two identical video projectors (Acer P1266P, XGA projector, 2700 ANSI Lumen, 2700:1 contrast). They were powered by 150 W UHP lamps (Derra et al, 2005). All three channels of the projectors were used (RGB white).…”

Ultra-high purity tungsten and its applications

“…SuperMINI or Short arc from GE Lighting, UHP lamps for projection systems from Philips Lighting), as shown in Fig. 6 [1,4]. In these lamps, W electrodes are operated at the temperature close to the melting point of W (3422°C).…”

Investigating the gas phase emitter effect of caesium and cerium in ceramic metal halide lamps in dependence on the operating frequency

“…A powerful broadband light source with a high radiance within the visible spectral range and a temporarily very stable emission is realized with an ultra high pressure (UHP) lamp [34]. The UHP lamp (Philips 228 L4), originally designed for video projection systems, is electrically driven by the electronic circuit from a video projector.…”