Film optical image bar code reader

A method in a film scanner of adaptively locating and reading a bar code image imprinted adjacent an edge of a filmstrip, the bar code image having abutting rows of clock and data elements said clock elements having a line of edge transition extending longitudinally along the filmstrip, the film scanner having an illuminant source and a linear light sensor array for detecting light from the illuminant source transmitted through said bar code image, the method comprising:

• passing said filmstrip bar code image over a bar code scanning aperture;
• transmitting said illuminant light through said bar code image and scanning aperture toward said light sensor array thereby defining a window of exposure of said illuminant light onto said linear light sensor array;
• processing output information from said light sensor array to determine lateral location of said clock element line of edge transition;
• establishing clock and data element detection windows at predetermined spaced locations from said located longitudinally extending edge transition of a clock element;
• and
• determining binary values of the clock and data elements in the bar code image from light sensor array output information in said clock and data element detection windows.

A method in a film scanner of adaptively locating and reading a bar code image imprinted adjacent an edge of a filmstrip, the bar code image having abutting rows of clock and data elements said clock elements having a line of edge transition extending longitudinally along the filmstrip and said bar code includes an entry element comprising a clock and data element of high density, the film scanner having an illuminant source and a linear light sensor array for detecting light from the illumninant source transmitted through said bar code image, the method comprising:

• passing said filmstrip bar code image over a bar code scanning aperture;
• transmitting said illuminant light through said bar code image and scanning aperture toward said light sensor array thereby defining a window of exposure of said illuminant light onto said linear light sensor array;
• processing output information from said light sensor array to determine lateral location of said clock element line of edge transition;
• establishing clock and data element detection windows at predetermined spaced locations from said located longitudinally extending edge transition of a clock element,
• defining lateral beginning and end points of said aperture window by an open gate line scan and thereafter processing said output information from within said defined beginning and end points of the aperture window to locate said edge transition of a clock element;
• and;
• determining binary values of the clock and data elements in the bar code image from light sensor array output information in said clock and data element detection windows.