Abstract: An illumination system for a video-imaging device has a light source and a collector of light from the light source. The collector is formed according to the principles of non-imaging optics and receives a portion of the light from the light source. The collector is configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device.

Abstract: An illumination system for a video-imaging device has a light source and a collector of light from the light source. The collector is formed according to the principles of non-imaging optics and receives a portion of the light from the light source. The collector is configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device. This system is highly efficient and compact compared to systems based on imaging optics, and can eliminate some of the components required for systems based on imaging optics. More extensive illumination systems are also disclosed.

Abstract: A light delivery system includes a light source. A first generally tubular, hollow coupling device with an interior light-reflective surface receives light from the source at an inlet and transmits it to an outlet. The coupling device increases in cross sectional area from inlet to outlet in such manner as to reduce the angle of light reflected from the surface as it passes through the device. A thermal-isolating region has an inlet positioned in proximity to an outlet of the coupling device and has an outlet for passing light to an optical member, the thermal-isolating region comprising one or more members. A waterproof container for the light source and coupling device has an aperture allowing light to pass out of the container. The aperture is sealed in part by a portion of a member of the thermal-isolating region. Advantageously, the system can be buried beneath the surface of the ground. This avoids the problem of people or equipment colliding with the system.

Abstract: A low voltage DC input ballast circuit for a discharge lamp particularly suitable for a central lighting system includes an input filter stage which feeds into a first boost converter circuit controlled by way of a pulse width modulator device. The first boost converter provides warm-up and steady state run signals to the lamp in a voltage fed manner over a coupling circuit using components which are reduced in size relative to conventional discharge ballast circuits. Control circuitry provides various monitoring functions, an example of which is that, in the event of a low input voltage, the lamp will operate in a dimmed or faded manner rather than maintain lumen output by drawing additional current. A second boost converter circuit is associated with a starter circuit arrangement and operates such that starting pulses can be generated and repeated if necessary in a very rapid manner.