The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 21, 1978
Filed:
Jun. 11, 1976
William F Schreiber, Cambridge, MA (US);
ECRM, Inc., Bedford, MA (US);
Abstract
Improvements in apparatus for making a halftone reproduction of an original document, of the type having an optical system comprising a source of light and a deflecting member for providing deflecting scanning and recording beams, a drive for providing relative motion between the original document and the scanning beam in a direction transverse to the direction of deflection thereof so that the scanning beam will trace a succession of scan lines across the document respectively during a succession of scanning cycles, an electro-optical pickup operative during each scanning cycle to detect the light from the scanning beam after it has impinged upon the document and to thereby provide an electrical output representative of the tone density (including any variation thereof) of the document along the scan line traced during that scanning cycle, video circuitry connected to the pickup for converting the electrical output into a video signal, a source of a succession of dot reference signals representative of the desired halftone screening pattern, output circuitry responsive to the reference and video signals to repeatedly compare the reference signals corresponding to the various cells of the halftone screening pattern with successive samples of the video signal and to generate halftone recording signals in accordance with the results of the comparison, a modulator in the optical system responsive to the output circuitry and operative during a succession of recording cycles to modulate the recording beam in accordance with the halftone recording signals, and a drive for providing relative motion between photosensitive output stock and the modulated recording beam in a direction transverse to the direction of deflection thereof so that the recording beam will trace a succession of record lines across the output stock respectively during the succession of recording cycles to record black and white dots in the cells of the halftone screening pattern.