摘要 |
A slit beam of coherent light is scanned across a flat finger print or fingerpress to provide a modulated reflected light beam. A Fourier transform of the modulated light beam is projected onto a hologram of a standard character plate. The character plate, from which the hologram is made, contains standardized minutia; specifically, line bifurcations and line endings, that are typical of a finger surface image. Correspondence between one of the minutia being scanned and one of the minutia in the character plate results in correlation of the Fourier transform of the minutia being scanned with the hologram of the corresponding minutia on the character plate to produce a correlation beam. An array of photocells is placed optically downstream from the hologram. Excitation of one of the photocells by one of the correlation light beams serves to identify the minutia being scanned by type of minutia, position of minutia and angular orientation thereof.
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