Eastman-kodak Company

Thomas D Carr

Robert E Swanson

George W Brock

Jay D Freeman

Frederick Rockwell Chamberlain, Iv

Norman L Koren

James Richard Harrer

How J Tsao

Peter J Mojsej

In a photographic film having a substantially transparent magnetic layer, and a sequence of longitudinally spaced image frames, the improvement comprising:

Data format for magnetically coated film

A single use camera is preloaded with a roll of magnetically coated film with defined image frames. The camera has an exposure system for selectively exposing an image frame of the film in one of a plurality of image formats. The camera also includes a manually actuated mechanism coupled to a mounted permanent magnet. The magnet is movable to record a magnetic mark on the magnetically coated film at a predetermined location relative to an exposed image frame. The location of the mark is indicative of the image format of the exposed image frame.

Advanced photo system format selector

A data recovery technique for jitter tolerant peak detected channels. The number of consecutive zeros between ones are reproduced in a run-length coded, peak detected channel. The interval (time, distance) is measured between peaks of a run-length encoded digital data signal wherein peaks represent ones and absence of peaks represent zeros. A look-up-table is provided having entries for all possible intervals between peaks for the run-length code used and corresponding entries for the number of zeros between ones. The measured interval is applied to the look-up-table to produce a string of zero bits between one bits.

Data recovery method and apparatus for jitter tolerant peak detected

An input string of binary data bits which is a random sequence of 0s and 1s is selectively spaced encoded into an output string of binary channel bits which is a sequence of 0s and 1s. An input string of binary data bits are recursively encoded according to run-length selection means having rate p/q where p is the number of input data bits that are encoded into q-channel bits. The channel bits obey constraints such that the encoding specifies an ordered n element list of integers that are the lengths of the selected runs of consecutive zeros, denoted b.sub.0 -1, b.sub.1 -1, . . . , b.sub.n-1 -1, and such that the element list of integers does not contain all the integers between the minimum element, b.sub.0, and the maximum element, b.sub.n-1.

Nonlinear run-length coding

In a magnetic recording reproducing apparatus, a detecting and decoding circuit comprising:

Simple pulse position modulation channel/decoder

In a camera having an exposure gate and a transport for transporting film past the exposure gate, the film having a series of perforations along at least one edge of the film, wherein the number of the perforations are an integer per exposure frame, the film having a substantially transparent magnetic layer at least in the region of the perforations, a mid-roll change apparatus. The mid-roll change apparatus includes a source of a steady-state magnetic field located downstream of the exposure gate and adjacent to the series of perforations for magnetizing the magnetic layer between the perforations as film is transported past the source; a magnetic field sensor located upstream of the exposure gate and adjacent to the series of perforations for sensing fringing magnetic fields emanating from perforation edges, the area between which have been magnetized; and a perforation sensor located to sense the series of perforations of the film.

Mid-roll change for film having edge perforations and magnetic layer on

In a camera having an exposure film gate and device for advancing a film strip past the gate, the film strip having successive image areas with a magnetic track adjacent to each image area, wherein one or more of the image areas are exposed and have information magnetically recorded in the adjacent magnetic track of an exposed image area, the improvement comprising a thin film read only magnetic sensor located relative to the film gate so as to be upstream of the gate when the means advances the film strip past the gate, the sensor reading each the magnetic track adjacent to an image area to determine whether the image area has been exposed or not so as to detect an unexposed image area before it is advanced to the film gate.

Camera having an upstream read only magnetic sensor to detect exposed

A digital data reproducing circuit for use with a magnetic or optical data storage for detecting and flagging signal level drop-outs in pulse position modulated (PPM) recorded signal levels. Positive and negative peak amplitudes of a self-clocking PPM coded signal are compared to positive and negative valid information peak detectors to detect the clock and PPM data. Lower peak (in absolute terms) amplitudes that fall from the normal signal levels at the start of a drop-out and/or rise at the end of the drop-out, are detected by positive and negative drop-out peak detectors. The positive and negative drop-out peak detectors are inhibited when valid clock and data peak pulses are detected.

Drop-out location detection circuit

A method of and apparatus for decoding data from positive and negative pulses of an encoded pulse train, e.g. a NRZ pulse train for PPM encoding, wherein the recorded data is subject to drop-outs and drop-ins. Data bits are decoded from valid positive and negative pulses exceeding positive and negative peak pulse thresholds. Drop-outs are identified in the encoded pulse train as a function of read out positive and negative pulse magnitudes not exceeding positive and negative thresholds, and drop-out flags are provided in lieu of the respective positive and negative pulses. Decoded data bit signs are stored in memory locations, and drop-out flags are stored in memory locations in relation to the stored data bit signs such that the beginning and/or end of a drop-out in the encoded pulse train is indicated. Drop-out flags are also stored in response to the occurrence of two successive valid positive pulses or two successive valid negative pulses in the pulse train. Additionally, drop-out flags are stored in response to the time out of an interval between successive positive or negative pulses. The drop-out flag may also be stored in a memory location in relation to the preceding decoded data storage location such that the last valid data prior to the beginning of the drop-out in the encoded pulse train is indicated.

PPM decoder utilizing drop-out location information

A magnetoresistive magnetic field sensor with a very long active region and a transduction signal of adequate power is achieved without the need to substantially increase voltage or current densities. The sensor is subdivided into multiple sub-elements which are connected in parallel. The transduction signal is produced from the sum of the changes in voltage across each of the sub-elements.

Magnetoresistive magnetic field sensor divided into a plurality of

A self-aligning configuration for establishing precisely where each of any number of tracks is to be recorded on a magnetic tape, utilizes therefor a photosensitive element (of perhaps even coarser structure than that of a given track), the signal output of which constitutes a measure of the location of the track(s). Thereafter, tracking control, say during playback, is pursuant to such signal, which is memorized.

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Leucadia, CA, United States of America

Thomas D Carr