Patent ID: 6273775
Filing Date: 2001-08-14
Classification: F21V,F21Y,G09F,Y10S

Abstract:
A method for designing an illuminated grid sign having a plurality of lengthwise sections of light-emitting luminous tubing and a plurality of concavely-curved reflective channels each positioned to reflect a portion of the light emitted by one of said lengthwise sections, the method comprising:selecting a maximum viewing angle (.alpha.) from a horizontal line of sight of an observer to the sign;selecting the luminous tubing, said tubing having an inside radius (r) and an inner surface having a reflector-closest edge;determining a minimum distance (d) between the tubing inner surface reflector-closest edge and a tubing-closest edge of the reflective channel adjacent thereto; andforming the reflective channels to be substantially semi-cylindrical with a radius (R) approximately equal to about 80% to about 120% of r.times.(1+1/(sin .alpha.))+d and an angle of wrap (.beta.) no greater than about 180.degree..