Latent image barcode
Encyclopedia
A latent image bar code (LIBC) reader located in relation to a filmstrip transport path for reading bar code data imprinted on the edge of a filmstrip. The LIBC reader comprises at least one illumination source and linear array of CCD
elements extending transversely from one side wall of the film transport path. When suitably clocked out, each CCD element provides a signal dependent on the intensity of the illumination received. The output signals from the CCD array are processed to detect an edge of the filmstrip by the contrast in signal amplitude due to attenuation of the transmitted light intensity by the filmstrip
substrate at the junction of the filmstrip with a gap separating the filmstrip edge and the side wall of the transport path. Once the edge of the filmstrip is identified, the output signals of segments of the CCD array aligned with the clock and data tracks of the bar code are sampled, digitized and compared to reference signals to discern the bar code pattern in the clock and data tracks. The bounds of the segments of CCD elements sampled are preferably set as sample time boundary functions triggered on edge detection.
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
elements extending transversely from one side wall of the film transport path. When suitably clocked out, each CCD element provides a signal dependent on the intensity of the illumination received. The output signals from the CCD array are processed to detect an edge of the filmstrip by the contrast in signal amplitude due to attenuation of the transmitted light intensity by the filmstrip
Filmstrip
The filmstrip was a common form of still image instructional multimedia, once commonly used by educators in primary and secondary schools , now overtaken by newer and increasingly lower-cost full-motion videocassettes and DVDs...
substrate at the junction of the filmstrip with a gap separating the filmstrip edge and the side wall of the transport path. Once the edge of the filmstrip is identified, the output signals of segments of the CCD array aligned with the clock and data tracks of the bar code are sampled, digitized and compared to reference signals to discern the bar code pattern in the clock and data tracks. The bounds of the segments of CCD elements sampled are preferably set as sample time boundary functions triggered on edge detection.
Related websites
Patents- http://www.freepatentsonline.com/5448049.html - Patent for Latent image barcode.