Method and apparatus for photographically recording digital audio and a

Abstract

A method and apparatus for photographically recording digital audio signals, and a medium having digital audio signals photographically recorded thereon. In a preferred embodiment, a motion picture film recorded in accordance with the invention has multiple digital audio soundtracks and an analog audio soundtrack photographically recorded thereon. Two or more channels of digital audio information can be recorded in each digital soundtrack, along with additional digital information for clocking, tracking, and error detection and correction. Each digital soundtrack is recorded in an array of bit areas arranged in row and column order. In a class of preferred embodiments, each row of digital audio bits is recorded simultaneously by exposing the film to radiation that has been modulated by a linear shutter array. The radiation transmitted by each shutter array is projected onto a row of spots. Each spot covers the full width of one of the bit areas in a row, but only part of the length of the bit area. As the medium is translated continuously (lengthwise) relative to the projected spots, each of the spots sweeps across a bit area, thereby recording a bit in the bit area which it sweeps in a manner analogous to painting the bit area with a paint brush.