This invention relates to a system for monitoring the movements of people in an office or other environment. Each room to be monitored has within it a sensor responsive to signals transmitted by identifiers worn by the people whose movements are being tracked. The identifier signals give the identity of the person allocated that identifier. The sensors are themselves polled periodically by a computer to generate time-stamped records of who was within range of which sensor. When an event is to be recalled, other time-stamped audio or video records of what was said or done in each monitored room are scanned for that record which was being generated at the time of the event in question.

A print format changing system includes a printer, a device for inputting print format-related information, and a memory containing an edit table region for storing the print format-related information input by the input device, thereby rewriting the print format-related information stored in the edit table region of the memory so as to change the format of data printed out by the printer.

There is a composite image filing system in which optical discs and microfilms are organically combined and integrally managed. This system comprises optical discs and microfilms in which image files are recorded and a work station to register, search, and process the image files. The work station has a memory to store search information of a format integrated between the optical disc and the microfilm. The search information which specifies the image files includes information indicative of the kind of medium (microfilm and optical disc), information to specify the medium number of the optical disc and the physical address in the optical disc in the case of a optical disc file or to specify the cartridge number and frame number in the case of a microfilm file, and the file name. The work station manages the image files by the search information and controls the optical disc so as to back up the search information corresponding to the image files recorded in the optical discs. Since the search information of the image files is stored into a backup dedicated memory such as optical disc or floppy disc nearest to the operation unit, the security of the search information is assured and the search information can be easily managed and reconstructed from the backup dedicated memory.

A digital camera is used to scan documents and generate a corresponding digital output signal. A data processor receives the digital output signal and generates corresponding index information. The video and index information are then stored on one or more optical disks for search and retrieval.

A file system is capable of retrieving image information stored in a microfilm file and image information stored in a disk through common input information.