V.   UNIGLO®  BACKLIGHTING

Poly-Optical's patented UniGlo  technology is a proprietary abrasion process that causes plastic optical fiber  panels to glow uniformly.  Most UniGlo  processed backlighting panels are constructed of .010" diameter plastic optical  fibers.  Utilizing a reflective backing,  the panel can be as thin as .013" for a single layer device.  Two or more layers provide greater brightness  and improved uniformity.  This technology  is ideal for backlighting membrane switches, LCDs, panels, control consoles,  PRNDLs, keyless entry, machine vision, man-machine interface, elastomeric  keypads, courtesy lights, signs, and point of purchase (POP) overlays.  Fig. V-1 shows a typical UniGlo backlighting  panel.

The thin profile and flexibility of UniGlo  backlighting panels allows placement between an elastomeric keypad or overlay  and a non-tactile or tactile dome membrane switch.  When the elastomeric or overlay is depressed,  the UniGlo panel flexes, easily allowing actuation of the switch. Typically, a  membrane switch requires 10 to 14 ounces of actuation pressure.  UniGlo backlighting panels slightly increase  the snap-through actuation pressure a minor amount as shown in table V-I: 

An independent laboratory conducted  Mechanical/Temperature Life Cycling tests on one-layer and two layer UniGlo  backlighting panels.  The panels were  placed between an overlay and a membrane switch and were actuated over five  million cycles at room temperature.  Panels were similarly tested for one million cycles at -10° C, and then, one million cycles at  -50° C.  The  panels tested showed no signs of light transmission degradation after any of  these tests.  In addition, panels were  successfully tested for one million cycles at -55° C.   

Type of  Switch Dome Alone UniGlo Single Layer D Change in Force UniGlo Double Layer D Change in  Force Metal Dome 424  gms. (15.0  oz) 447  gms. (15.8  oz) 23 (0.8) 478  gms. (16.9  oz) 54 (1.9) Plastic Dome 239  gms. (8.4  oz) 288 gms (10.2  oz) 19 (1.8) 313  gms. (11.0  oz) 749 (2.6) Non-Tactile 237  gms. (8.4  oz) 242  gms. (8.5  oz) 5 (0.1) 258  gms. (9.1  oz) 21 (0.7)

Table V-I  (Force Test Data)