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:
Aug. 28, 1990
Filed:
Mar. 18, 1988
Applicant:
Inventors:
Thomas I Bradshaw, Afton, MN (US);
Edward S Shinbach, St. Paul, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350102 ; 350105 ; 40564 ; 362 29 ;
Abstract
An internally illuminated sign employs retroreflective sheeting with optically transmissive bonds between cover layer and base layer, thereby making the sign suitable for applications where visibility of the sign is required if the internal illumination source fails. A light conduit may be employed to allow the source of internal illumination to be remote from the interior of the sign enclosure. Total internal reflection type sheeting also may be employed to diffuse the internal illumination.