Back to results
US 4,734,565 AGranted
Read-only optical card and system
AssigneeDrexler Technology Corporation
InventorsGerald A. Pierce, James L. Buxton
Life of this patent
Estimating the term…
Abstract
An optical data read-only card and system using a length of optical recording material in which data in the form of microscopic spots is disposed in cells forming a regularly spaced grid. The spots contrast with the background media with a reflective contrast ratio of at least 1.5 to 1. While the material is being moved in a lengthwise direction by a transport, rows of cells are being read one row at a time by a linear CCD array capable of detecting the contrasting reflectivities between spots and background.
Claims24
An optical data read system comprising,
- an optical data storage medium having optically readable digital data encoded by microscopic spots on said medium, the spots disposed in specified data cell positions, the cell positions forming a grid of perpendicular, non-overlapping rows and columns of cell positions, said columns aligned with a lengthwise direction of the medium, the spots having a reflective contrast ratio with respect to a surrounding field of said medium of at least 1.5 to 1, and
- a linear CCD array capable of detecting the reflective contrast between said spots and said surrounding field, said array on the same side of said medium as a light source aligned perpendicular to said columns of cell positions and having a plurality of fixed position detector cells imaging each specified data cell position in a row of cell positions, wherein at least two detector cells image a specified data cell position with groups of detector cells simultaneously imaging a plurality of cell positions.
An optical data card read-only system comprising,
- a data card having non-overlapping parallel rows of data cells arranged in groups of parallel columns, each data cell capable of holding a single bit of data of microscopic size having a reflective contrast ratio with respect to a surrounding field of the data card of at least 1.5 to 1, each group of columns of data cells spaced from a neighboring group of columns, thereby forming parallel bands of data,
- a beam source means for directing a light beam onto the card and beam detector means on the same side of said data card from said beam source means for reading said light beam after reflection from the card, said beam detector means capable of simultaneously reading a row of data cells, wherein said beam detector means include a linear array of fixed position detectors, wherein at least two detectors read each data cell, with groups of detector cells simultaneously imaging a plurality of cell positions, and
- card transport means for advancing said card relative to the beam source means and beam detector means so that succesive rows of data can be read.
A method of reading optical data stored on a card comprising,
- (a) reading data spots in a first row of a data card, the data spots disposed in parallel, non-overlapping rows and columns and having a reflective contrast ratio with respect to a surrounding field of the data card of at least 1.5 to 1, the data spots being read by a linear array of detector cells simultaneously imaging said data spots in said first row while said card is in a fixed position, each spot being read by at least two detector cells,
- (b) advancing said card an incremental distance,
- (c) reading data spots in a second row adjacent the first row while said card is in a second fixed position, and
- (d) repeating steps (b) - (c) for successive rows of spots.
1 more element
An optical memory card comprising,
- a substrate capable of supporting an optical data storage medium, and
- a data storage medium disposed on the substrate, the medium having a rectangular non-overlapping array of storage cells with a length dimension and a width dimension, some of said storage cells having data spots therein of microscopic size, the remaining storage cells being empty, said data spots having a reflective contrast ratio with respect to a surrounding field of the medium of at least 1.5 to 1, the data being arranged in rows along the widthwise dimension, at least one end of each row having spots marking the presence of a row, each of the storage cells in a row having a size capable of being imaged by at least two adjacent detector cells in a linear array.
Dependencies are inferred from the claim text.