Horizontal scan vertical simulation character reading

A method for overcoming variation in scan rate and in position of a character resulting from positional inaccuracies encountered in the use of hand-held scanning devices and/or loosely constrained document printing mechanisms and techniques, where said character is within a field of view of several character heights which comprises:

• a. sweeping a two-dimensional sensing array of several character heights horizontally along a line across a character field to provide an image output,
• b. applying the output of said array to a black/white thresholding circuit,
• c. shifting the thresholded image output of said array vertically through a recognition unit to stimulate vertical movement of said array relative to said line in one-cell-height increments at a rate such that all cells of the array are scanned in an interval required for movement of said field on said array of less than one resolution cell,
• d. attempting character recognition with each onecell-height increment, and
• e. sensing the output of said recognition unit.

The method of overcoming variations in scan rate and in position of a character within a field of view of several character heights, which variations result from positional inaccuracies caused by use of a hand-held scanning device and/or loosely constrained document printing mechanisms and techniques which comprises:

• a. sweeping a two-dimensional sensing array of about one character width and several character heights horizontally along a line across a character field,
• b. applying a matrix of output signals resulting from each said character to a recognition unit,
• c. vertically shifting a set of said signals through said recognition unit at a rate such that all cells of the array are scanned in an interval required for movement of said field on said array of less than one resolution cell,
• d. attempting character recognition with each onecell-height increment that said set is shifted, and
• e. producing a recognition output signal when a character in the shifted set is brought into registration with a set of inputs leading to said recognition unit.

A hand operated optical data acquisition and processing system which comprises:

• a two-dimensional photosensor array of height in cells approximately three times the array width in cells and generating binary signals representing an image,
• means to focus onto said array an image field past which said array moves with a character in the field spanning across the array,
• a first serial-in-parallel-out shift register of length in bit positions corresponding to the width in cells of said array,
• a second serial-in-parallel-out shift register of width in bit positions corresponding to the length of said first shift register and of height in excess of the height of a character in the field, said second shift register connected to the output bit positions of the first shift register, and
• means for shifting the binary signals serially into said first shift register and from the first register serially into the second shift register to simulate vertical movement of said array relative to said field at a rate in excess of the rate of movement across said field.