Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Hirsch, PM: AUTHOR [+3]
AbstractIllustrated is a character reader which is based on testing the characteristics of the character to be read.
Illustrated is a character reader which is based on testing the characteristics of the character to be read.
An incoherent but monochromatic light source 1 diffusely illuminates the character 2 which is to be read. In the figure, this is shown as a transparency, and for convenience no transport is shown. At 3 is a kinoform multiplexer which provides 12 or any other desired number of separate images 5 of the character. If a Fourier multiplexer is used as shown, a lens 4 is required. This lens may be included in the kinoform 3 to provide a Fresnel multiplexer. These multiple images 5 are then processed in an array of kinoforms 6, each of which acts as a matched filter for the 12 or more basic characteristics. The performance of kinoform filters for matched filtering is described in the IBM Journal of Research and Development, Vol. 14, page 485, published in 1970.
Assuming the array of kinoforms 6 to be Fourier filters, a lens array 7 is required to form the correlation of the basic characteristics encoded in the array of kinoforms 6 with the character 2 at the image plane 8. The lenses can be conventional lenses or kinoform lenses or the array can be replaced by a single very large lens. The focussing requirements of the lenses may be incorporated in the kinoform filters 6 to make Fresnel filters.
The several correlation patterns are obtained in the individual sectors 9 of the image plane 8. These patterns may be detected using video methods. If it...