Abstract: An illuminated sign designed to be viewed from a horizontal line of sight of an observer, the sign comprising: a frame, a partially transparent face thereon, tubing mounted therein and having an inside radius (r), and a single or plurality of concavely-curved, reflective channels each being substantially semi-cylindrical and having a radius (R), and positioned at a distance (d) from the luminous tubing; wherein the improvement comprises each channel having an angle of wrap (&bgr;) approximately equal to about 70% to about 150% of the value that solves the equation 1 sin ⁢ ( β 2 ) + 2 ⁢ ( R r - d r - 1 ) ⁢

Abstract: An illuminated sign designed to be viewed from a horizontal line of sight of an observer, the sign comprising: a frame, a partially transparent face thereon, tubing mounted therein and having an inside radius (r), and a single or plurality of concavely-curved, reflective channels each being substantially semi-cylindrical and having a radius (R), and positioned at a distance (d) from the luminous tubing; wherein the improvement comprises each channel having an angle of wrap (&bgr;) approximately equal to about 70% to about 150% of the value that solves the equation 1 1 sin ⁢ ( β 2 ) + 2 ⁢ ( R r - d r - 1 ) ⁢ cos ⁢ ( β 2 ) = R r .

Abstract: A method of designing an illuminated grid sign designed to be viewed at a maximum viewing angle (&agr;) from a horizontal line of sight of an observer. The method comprises selecting the maximum viewing angle (&agr;), selecting the illuminated tubing with inside radius (r), determining the minimum distance (d) between the tubing and the reflective channel, and designing the substantially semi-cylindrical reflective channels to have a radius (R) approximately equal to 80% to 120% of r×(1+1/(sin &agr;))+d and an angle of wrap (&bgr;) no greater than about 180°. The design method provides a sign that minimizes visible streaks of brighter and less-bright illuminated regions in the sign when viewed from an angle less than or equal to the maximum viewing angle (&agr;).

Abstract: An illuminated grid sign designed to be viewed at a maximum viewing angle (&agr;) from a horizontal line of sight of an observer, the sign comprising: a frame, a partially transparent face thereon, tubing mounted therein and having an inside radius (r), and a plurality of concavely-curved, reflective channels each having an angle of wrap (&bgr;) and positioned at a minimum distance (d) from the luminous tubing; wherein the improvement comprises each channel being substantially semi-cylindrical and having a radius (R) approximately equal to 80 to 120% of r×(1+1/(sin &agr;))+d.

Abstract: An alarm device for detecting movement of parked automobiles provides a support for mounting on an automobile. An outer member defines a ring having an inner surface of conducting material. A helical spring is attached to the support to suspend the ring in an attitude where the ring defines an aperture in cross-section. An inner member having an outer surface of conducting material is connected by a flexible connection to the support to be suspended in said outer member and spaced from the inner surface thereof.