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. 11, 1990
Filed:
Jun. 22, 1989
Applicant:
Inventors:
Marinus J Dona, Eindhoven, NL;
Johannes M Swinkels, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23B / ; G03B / ;
U.S. Cl.
CPC ...
82-111 ; 82 11 ; 82 111 ;
Abstract
A method of manufacturing a master for projection screens, according to which a pattern of parallel rectilinear grooves (31) and ribs (31) is formed on one side of a plate of machinable material by a slotting operation performed by means of a profile chisel. The grooves (33) are formed in several different tooling steps with, several grooves being tooled simultaneously. The profile chisel is of multiple construction and is composed of three subchisels, i.e. a precutting chisel, a cutting chisel (13) and a finishing chisel.