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Journal ArticleDOI

52.1: Invited Paper: New Developments in Projection Light Sources—Shorter Arcs and Miniaturisation

Holger Moench1, G. Derra1, Ernst Fischer1, H. Regt1, Xaver Riederer1 
01 Jun 2001-Vol. 32, Iss: 1, pp 1274-1277
TL;DR: In this paper, a reduction of the lamp ignition voltage from 20kV to 5kV was proposed, which enables a further step in system size reduction, and a new UHP lamp with higher power and shorter arcs was presented, which fulfilled the optical demands of future projectors and novel displays.
Abstract: New developments of UHP lamps with higher power and shorter arcs (even below 1mm) fulfill the optical demands of future projectors and novel displays. In addition a new technology is presented which leads to a reduction of the lamp ignition voltage from 20kV to 5kV. This enables a further step in system size reduction.
Citations
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Journal ArticleDOI
TL;DR: The UHP lamp concept features outstanding arc luminance, a well suited spectrum, long life and excellent lumen maintenance as discussed by the authors, and is one of the key enablers of the commercial success of projection systems.
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. (Some figures in this article are in colour only in the electronic version)

90 citations

Journal ArticleDOI
TL;DR: In this article, a framework of relations that describe the image of an extended source in the secondary focal plane of the ellipsoid is developed, and the propagation of rays depending of their origin and on their direction is investigated.
Abstract: Elliptical reflectors are widely used in illumination engineering as a means to concentrate the light of a source in the secondary focal plane. To collect as much light from the source as possible, the reflector must cover a wide angular range of the emitted radiation, hence forward and backward reflections on the reflector must be discussed and conditions for paraxial optics do not apply. We develop a framework of relations that describe the image of an extended source in the secondary focal plane of the ellipsoid. After deriving basic relations between object and image spaces, the propagation of rays depending of their origin and on their direction is investigated. As a result, the function and the aberrations of the reflector can be expressed in terms of an angular dependent magnification for longitudinal and lateral coordinates. With that, one cannot not only calculate luminance and illuminance distributions in the secondary focal plane in a straightforward manner, but can easily understand their properties and their dependence on ellipse parameters. On the basis of the developed relations, implications for the design of "elliptical" short arc high-intensity-discharge (HID) lamps for video projection are discussed.

43 citations

Patent
16 May 2003
TL;DR: In this article, an enhanced polarized light source for a display system was proposed. But the system was not designed for display applications, and it was not suitable for the use of a large number of LEDs.
Abstract: The present invention provides an enhanced polarized light source for a display system. In one embodiment, the invention includes a light source (11) to produce light having multiple polarization states, a relay optical system (23) to relay light imaged onto the relay optical system onto a display (17), an optical imaging element (25) to image light from the light source onto the relay optical system (23), a polarization separator (34) to direct light of a first polarization to a first portion of the optical imaging element and light of a second orthogonal polarization to a second portion of the optical imaging element, and a polarization conversion element (35) between the optical imaging element and the relay optical system to receive light having the second polarization from the optical imaging element and convert its polarization to the second polarization.

39 citations

Journal ArticleDOI
07 Aug 2002
TL;DR: A new class of compact high-definition electronic projection systems has emerged that are based on microdisplays that include small arc lamps, color separation and recombination optics, and rear-projection screens.
Abstract: A new class of compact high-definition electronic projection systems has emerged that are based on microdisplays. Very large scale integration process technology is adapted to fabricate the three classes of microdisplays: (1) transmissive liquid crystal on high-temperature polysilicon/quartz; (2) microelectromechanical devices on silicon; (3) and reflective liquid crystal on silicon. A variety of system architectures are discussed. Key ancillary technologies include small arc lamps, color separation and recombination optics, and rear-projection screens.

39 citations


Cites background from "52.1: Invited Paper: New Developmen..."

  • ...Fig. 16 illustrates the relationship for a 125-W lamp [ 22 ]....

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Proceedings ArticleDOI
TL;DR: A totally light-pipe based projection engine is described, which consists of an etendue efficiency illumination system using the dual paraboloid reflector system with a lensed tapered light pipe as the output.
Abstract: Projection engine designs are mostly based on discrete optical components including color filters, mirrors, relay lenses, prisms, etc., which tends to be expensive and increase the space requirement. With the advancement of light pipe based illumination system, e.g. the Wavien patented dual paraboloid reflector system, and light-pipe based polarization recovery system, it would be advantage to design a light-pipe based projection engine for a complete light-pipe based system for low cost and space saving applications. In this paper, a totally light-pipe based projection engine is described. It consists of an etendue efficiency illumination system using the dual paraboloid reflector system with a lensed tapered light pipe as the output. The output is then directed into a light-pipe based polarization recovery system such that the output is polarized. The polarized light is then separated into its individual RGB colors, and is directed into the corresponding HTPS imager chips separately by the use of light pipes, prism, and beam splitters. The outputs from the imager chips are then recombined by an X-cube and projected onto the screen. This light-pipe based system uses low cost optical components and take up much less space than the traditional projection system.

29 citations

References
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Patent
07 Jun 1995
TL;DR: In this article, a high pressure discharge lamp is operated by an apparatus coupled to the input terminals for supplying an alternating lamp current to the lamp, and a device (III) is provided for generating a current pulse in each half period of the lamp current.
Abstract: A circuit arrangement for operating a high pressure discharge lamp includes input terminals for connection to a supply voltage source and an apparatus coupled to the input terminals for supplying an alternating lamp current to the high pressure discharge lamp. A device (III) is provided for generating a current pulse in each half period of the lamp current. This current pulse has the same polarity as the lamp current and is superimposed on the lamp current in the latter part of a predetermined fraction of the half periods of the lamp current. The circuit substantially suppresses flickering of the discharge arc during lamp operation.

76 citations

Journal ArticleDOI
01 May 2000
TL;DR: By collecting data containing both the spatial and angular characteristics of light emitted from a short arc light source, a set of rays may be created in optical design software that accurately predicts the performance of the light source in a projection system as mentioned in this paper.
Abstract: By collecting data containing both the spatial and angular characteristics of the light emitted from a short arc light source, a set of rays may be created in optical design software that accurately predicts the performance of the light source in a projection system.

27 citations

Journal ArticleDOI
01 May 1999
TL;DR: In this paper, the UHP lamps combine highest brightness, extremely long life and system compactness for short arc lamps, and they are used for projection display technology, which requires a corresponding development of short arc lamp.
Abstract: The fast developments in projection display technology require a corresponding development of short arc lamps. Arc length and high luminance determine light collection rather than lamp power. The new UHP lamps combine highest brightness, extremely long life and system compactness.

25 citations

Journal ArticleDOI
01 May 2000
TL;DR: In this article, a new technology is presented which stabilises the lamp arc directly and keeps the good maintenance of the lamp, which is of limited use for small displays, but it can be used for high efficient projection systems.
Abstract: UHP-lamps are standard for high efficient projection systems. All short arc lamps show arc instabilities. Optical integrators can successfully suppress visual effects but they are of limited use for small displays. A new technology is presented here which stabilises the lamp arc directly and keeps the good maintenance of the lamp.

12 citations

Patent
Ernst Fischer1, Horst Horster1
17 Apr 1989
TL;DR: In this paper, a high-pressure mercury vapour discharge lamp with an envelope made from high-temperature-resistant material, which contains two electrodes (12, 13) made from tungsten and a filling in a discharge space, which filling essentially consists of mercury, rare gas, and a halogen that is free in the operating condition.
Abstract: The invention relates to a high-pressure mercury vapour discharge lamp (1) with an envelope (2) made from high-temperature-resistant material, which contains two electrodes (12, 13) made from tungsten and a filling in a discharge space (14), which filling essentially consists of mercury, rare gas, and a halogen that is free in the operating condition. According to the invention, the envelope (2) has a second space (15, 16).

11 citations