Method and apparatus for magnetic communication via a photographic filmstrip using trappable data sentinels
AssigneeEastman Kodak Company
InventorsGary L. Robison, Fernando G. Silva
Life of this patent
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Abstract
Overhead and data loss are reduced when transferring data via magnetic recording in a magnetic layer of an elongate photographic filmstrip, by providing a trappable data sentinel at the beginning of a data field. The data sentinel comprises a pair of reserved characters which establish a data character boundary for data in the field and also identify the nature of this data. The data sentinel is trapped by an identity comparator and also read by a host computer or processor. Data fields employing the data sentinel format can be embedded within a start sentinel/end sentinel track architecture.
Claims24
Apparatus for use in a stage of film use and processing wherein the film comprises an elongate photographic film strip having successive frames and wherein data is transferred between stages via a magnetic layer of the film strip, comprising:
- first means for reading data magnetically recorded in a track in said magnetic layer, said track including a data field comprising a trappable data sentinel and one or more data characters;
- second means for unambiguously identifying the trappable data sentinel in the read data;
- and
- third means for:
- determining, in response to identification of said data sentinel, a character boundary for said data field;
- parsing the data field into characters beginning at said character boundary;
- and interpreting so parsed data characters of said field based upon reading of said data sentinel.
In a method for transferring data from a first stage to a second stage of photographic film strip use and processing wherein data is magnetically recorded in a data field in a magnetic layer of an elongate photographic film strip at said first stage for readout by a magnetic read head at said second stage, and wherein the data is susceptible to corruption error during data transfer, the improvement comprising:
- defining a trappable data sentinel comprising a particular sequence of bits which appears nowhere else in a valid data stream;
- formatting said data field in the following sequence:
- the trappable data sentinel, one or more data characters, and an error checking character;
- recording the formatted data field in a track in the magnetic layer of the photographic film strip at said first stage;
- and at the second stage:
- detecting the data sentinel;
- reading the data field;
- parsing the read data field into characters with reference to a character boundary established in response to the detected data sentinel;
- and
- interpreting the data characters with reference to a data type identification provided by the data sentinel.
Dependencies are inferred from the claim text.