Digital information system.

摘要

The display system has projectors (22) at a number of public places, e.g. railway stations. The projectors are connected and controlled by local computers (34,38) that are linked through a communication system, e.g. radio (14), to a central computer system (10). Projectors are many places of different types can be linked to this system. Also connected to the central system are information mediators (24). These may be advertisers or any other source requiring to present public displays. The information suppliers can be allowed to directly book dispaly time slots through the central computer which then organised the distribution of the display material.