Abstract: The invention provides a method and apparatus for providing a uniform output from an optical transmitter. The invention comprises at least one discrete light source (30), and a housing (38) defining an internally reflecting volume (42) for light from the at least one light source, the housing having a light exit aperture (46) for light from the at least one light source. The reflecting volume is adapted to produce in an extended image surface multiple reflected images (50) of the at least one light source, and the light exit aperture is arranged to emit light from the multiple reflected images. An output lens (48) is employed in front of the light exit aperture for controlling the angular distribution of the light emitted from the at least one light source and the multiple reflected images by way of the light exit aperture.

Abstract: The invention provides an optical collection device (26) comprising a first stage optical concentrating device (34) and a second stage optical collection unit (40) having a housing (42) and an array of individual light collecting elements (46) in the housing. The array of light collecting elements provide, in combination, a light entrance and a light exit, each light collecting element having a light entrance aperture (62), a light exit aperture (64), and a light collecting region (44) extending between the entrance aperture and the exit aperture. The light collecting region provides a tapering light reflecting surface (66) arranged to direct light received at the entrance aperture towards the exit aperture. The invention also provides an optical receiver (20) comprising such an optical collection device and having at least one detecting element (24, 72, 74) arranged behind the light exit apertures to detect light transmitted by the optical collection unit.

Abstract: After the claims, please insert the following Abstract:—The invention provides a broadband mass communications network system and method comprising a plurality of patches (10), each patch including a plurality of subscribers, and each subscriber having a respective subscriber unit (12) for transmitting signals to and receiving signals from other subscribers. Each subscriber unit comprises an indoor interface unit (20) for user access to the system and an outdoor mounted communication unit (18) for the transmission and reception of signals. The signals are impressed on a carrier signal operating at frequencies in the range from infra-red to ultra-violet, the subscriber units of a respective patch being arranged to transmit the carrier signals substantially omni-directionally and to communicate by way of direct line of sight connections within the patch.

Abstract: A distributed computer system is provided with a listener system interposed between the application server and the surface interfaces of the system. The listener system supervises processing of user entered commands and provides substantially simultaneous feedback of system status and progress of the system response to a command to all users. This allows system users to work simultaneously on a common document.