Patent · US Expired

Process for recording semihalftone images and device for conversion of image dot tonal value data

US4939589A · kind A · utility

7Cited by

5References

16Claims

0Family size

Assignee

E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

Gerhard Fischer · Offenbach, DE
Helmut Quabeck · Babenhausen, DE

Key dates

Filing date	May 31, 1988
Grant date	Jul 3, 1990
Priority date	—
Expiry date	May 31, 2008

Classification

Technology area (CPC H)Electricity
CPC primaryH04N1/4051
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

The invention provides for deciding whether a recording dot is to be printed for the reproduction of scan dots. The scan dots being considered are compiled in an input switching network into groups, for which an arithmetic processor determines the tonal value sum. The arithmetic processor emits a signal, if the tonal value sum exceeds a certain figure. The recording dot to be printed is determined by the presence of the signal in an output switching network. This process is performed successively for increasingly larger areas of the original, that is, for increasingly larger quantities of scan dots.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.