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:
Sep. 08, 1987
Filed:
Feb. 05, 1985
Kunio Ikuta, Kyoto, JP;
Dainippon Screen Mfg. Co., Ltd., Kyoto, JP;
Abstract
Halftone dots are formed pixel by pixel onto a photosensitive film of a size P.times.P in an improved manner by using a screen memory storing thresholds, each of which corresponds to each of m.times.n sub-cells of a halftone dot area of the size S.times.S. In accordance with the invention, four table memories are prepared by respectively storing values ##EQU1## with y.sub.n being the main scanning direction addresses and x.sub.n being the sub-scanning direction addresses. Values read from the first table memory and values read from the second table memory are summed to obtain the sub-scanning reading addresses of the screen memory, while the values read from the third table memory and the values read from the fourth table memory are summed to form the main scanning reading addresses of the screen memory. At this junction, the values (1) to (4) to be stored in each of the table memories are permitted to be residues, taking advantage of the characteristic that the values are periodic. Additionally, the memory capacity required for the operation can be permitted to be smaller by taking advantage of the characteristic that the values of interest form an arithmetic series.