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:
Oct. 01, 1991
Filed:
Aug. 15, 1990
Applicant:
Inventor:
Ian K Pasco, Slough, GB;
Assignee:
Techophone Limited, Surrey, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
362 24 ; 362 27 ; 362 31 ; 40546 ;
Abstract
A light guide for illuminating a keyboard or keypad from behind comprises a transparent grid-like plate having an array of apertures in each of which is accommodated a respective key of the keyboard/keypad. The transparent plate comprises an integral lens aligned with a reflector for directing light from an external source into the plane of the plate. Various plane reflecting surfaces are provided for reflecting the light in a localized path completely surrounding each of the apertures. This arrangement enables the keys to be illuminated with a high degree of uniformity using only relatively few distributed light sources.