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:
Jun. 01, 1993
Filed:
May. 22, 1991
Hiroyasu Honda, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
In a bi-level displaying device, dither signal trains Y.sub.0 to Y.sub.15 for displaying half tone levels are generated from signal trains for basic tone levels X.sub.0 to X.sub.16 and from a 1/2 dither pattern constituted by the same numbers of dots having different threshold values. Dither signal trains Z.sub.0 Z.sub.31 for displaying unequally divided intermediate tone levels are generated by the basic trains X.sub.0 to X.sub.16 from a 1/4 dither pattern and a 3/4 dither pattern which are associated with unequal numbers dots having the different threshold values. Since the unequally divided intermediate tone levels can be displayed easily, it becomes possible to get natural intermediate tone levels. A dither pattern having a reversed pattern is adopted so that twice the number of intermediate tone levels can be displayed. Hence, a total of 64 tone levels can be displayed to produce images with fine detail and high resolution.