ИСТИНА

In an optical medium such as a fluorescent multilayer disk (206), both reading speed and storage capacity are increased in various ways. Multiple heads (103) can be provided, in which case one head reads information while another moves from one reading position to the next. An optical head can read from several tracks on a disk simultaneously by focusing the exiting light into a light strip and using a photo-sensor array (210). The information pages in each layer can be staggered from those in adjacent layers. The number of layers in a medium can be selected by maximizing capacity with respect to numerical aperture. To increase exposure time, a reading head can follow the medium for one reading operation and then return to its initial position for the next reading operation