Method and apparatus for reading photographically recorded digital audio soundtracks

Claim 1

An apparatus for reading rows of digital audio bits that have been recorded photographically in bit areas of a motion picture film having a longitudinal axis, including: a film transport means for continuously translating the film along a path parallel to the longitudinal axis; a first array of radiation detectors mounted in a detector plane, wherein each of the detectors in the first array has a length L along a first axis parallel to the longitudinal axis and width W along a second axis substantially perpendicular to the longitudinal axis; a first axis means for directing a first laser beam through a first region of the film at a first location along the path, wherein the first region is oriented substantially perpendicularly to the longitudinal axis; and first lens means for receiving the first laser beam after it has propagated through the first region, converting the first laser beam into a first expanded beam, and projecting the first expanded beam onto a row of spots in the detector plane, wherein the row of spots extends along the second axis, wherein each of the spots has a length S along the first axis, wherein the length S is greater than the length L, wherein each of the spots has a width, along the second axis, equal to at least an integral multiple of the width W, wherein the bit areas are located within at least two spatially separated elongated soundtrack regions of the film, wherein the elongated soundtrack regions are oriented substantially parallel to the longitudinal axis, and wherein the first region intersects a first one of the elongated soundtrack regions; a second array of radiation detectors mounted in a second detector plane, wherein each of the detectors in the second array has a length M along a third axis and a width X along a fourth axis, a second laser means for directing a second laser beam through a second region of the film, wherein the second region is oriented substantially perpendicularly to the longitudinal axis and intersects a second one of the elongated soundtrack regions; a second lens means for receiving the second laser beam after it has propagated through the second region, converting the second laser beam into a second expanded beam, and projecting at least a portion of the second expanded beam onto a second row of spots in the second detector plane, wherein the second row of spots extends along the fourth axis, each of the spots in the second row has a length T along the third axis, and the length T is greater than the length M; a third array of radiation detectors mounted in a third detector plane, wherein each of the detectors in the third array has a length N along a fifth axis and a width Y along a sixth axis; and wherein the second lens means projects a portion of the second expanded beam onto a third row of spots in the third detector plane, wherein the third row of spots extends along the sixth axis, each of the spots in the third row has a length U along the fifth axis, and the length U is greater than the length N.

Claim 2

An apparatus for reading rows of digital audio bits that have been recorded photographically in bit areas of a motion picture film having a longitudinal axis, including: a film transport means for continuously translating the film along a path parallel to the longitudinal axis; a first array of radiation detectors mounted in a detector plane, wherein each of the detectors in the first array has a length L along a first axis parallel to the longitudinal axis and width W along a second axis substantially perpendicular to the longitudinal axis; a first axis means for directing a first laser beam through a first region of the film at a first location along the path, wherein the first region is oriented substantially perpendicularly to the longitudinal axis; and first lens means for receiving the first laser beam after it has propagated through the first region, converting the first laser beam into a first expanded beam, and projecting the first expanded beam onto a row of spots in the detector plane, wherein the row of spots extends along the second axis, wherein each of the spots has a length S along the first axis, wherein the length S is greater than the length L, wherein each of the spots has a width, along the second axis, equal to at least an integral multiple of the width W, wherein the bit areas are located within at least two spatially separated elongated soundtrack regions of the film, wherein the elongated soundtrack regions are oriented substantially parallel to the longitudinal axis, and wherein the first region intersects a first one of the elongated soundtrack regions; a second array of radiation detectors mounted in a second detector plane, wherein each of the detectors in the second array has a length M along a third axis and a width X along a fourth axis, a second laser means for directing a second laser beam through a second region of the film, wherein the second region is oriented substantially perpendicularly to the longitudinal axis and intersects a second one of the elongated soundtrack regions; a second lens means for receiving the second laser beam after it has propagated through the second region, converting the second laser beam into a second expanded beam, and projecting at least a portion of the second expanded beam onto a second row of spots in the second detector plane, wherein the second row of spots extends along the fourth axis, each of the spots in the second row has a length T along the third axis, and the length T is greater than the length M; a third array of radiation detectors mounted in a third detector plane, wherein each of the detectors in the third array has a length N along a fifth axis and a width Y along a sixth axis; and wherein the second lens means projects a portion of the second expanded beam onto a third row of spots in the third detector plane, wherein the third row of spots extends along the sixth axis, each of the spots in the third row has a length U along the fifth axis, and the length U is greater than the length N.

Claim 13

A method for processing a digital playback signal from a digital optical soundtrack read head, and an analog playback signal from an analog optical soundtrack read head, wherein the digital playback signal comprises blocks of bits, wherein the digital playback signal is indicative of digital audio bits read from bit areas of a photosensitive medium, and wherein the digital playback signal is also indicative of error code bits read from bit areas of the photosensitive medium, including the steps of: performing an error detection operation on the digital playback signal to generate an error corrected digital playback signal; generating an error rate signal for each of the blocks of the digital playback signal; integrating each said error rate signal to generate a filter control signal; filtering the error corrected digital output signal in a low-pass-filter means in response to the filter control signal to generate a filtered corrected digital playback signal; generating a first analog signal from the filtered corrected digital playback signal; and receiving the first analog signal, the analog playback signal, and a control signal, and generating an output signal consisting of selected portions of the first analog signal concatenated with selected portions of the analog playback signal in response to the control signal.

Claim 14

A method for processing a digital playback signal from a digital optical soundtrack read head, and an analog playback signal from an analog optical soundtrack read head, wherein the digital playback signal comprises blocks of bits, wherein the digital playback signal is indicative of digital audio bits read from bit areas of a photosensitive medium, and wherein the digital playback signal is also indicative of error code bits read from bit areas of the photosensitive medium, including the steps of: performing an error detection operation on the digital playback signal to generate an error corrected digital playback signal; generating an error rate signal for each of the blocks of the digital playback signal; integrating each said error rate signal to generate a filter control signal; filtering the error corrected digital output signal in a low-pass-filter means in response to the filter control signal to generate a filtered corrected digital playback signal; generating a first analog signal from the filtered corrected digital playback signal; and receiving the first analog signal, the analog playback signal, and a control signal, and generating an output signal consisting of selected portions of the first analog signal concatenated with selected portions of the analog playback signal in response to the control signal.