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Motorola
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Abstract
Current incandescent illumination systems for hand held communication devices (i.e. pagers, cellular phones, etc.) use multiple incandescent lamps to illuminate a display and/or flash lights to alert the user of an event. When illuminating a display, several lamps are used in conjunction with a diffuser to distribute the light more evenly across the display. Even with an efficient diffuser, areas of the display appear substantially brighter than other areas. This can be displeasing to the user and may make reading the display sometimes difficult. This problem can be minimized by adding more lamps but the chances for failures to occur increase proportionally. It would therefore be advantageous to use only one lamp for all the necessary illumination required by a hand held communication device while maintaining or improving the display illumination.
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MOTOROLA INC. Technical Developments Volume 12 April 1991
SWITCHABLE FIBER OPTIC ILLUMINATIqN SYSTEM
by Brad Murray
Current incandescent illumination systems for hand held communication devices (i.e. pagers, cellular phones, etc.) use multiple incandescent lamps to illuminate a display and/or flash lights to alert the user of an event. When illuminating a display, several lamps are used in conjunction with a diffuser to distribute the light more evenly across the display. Even with an efficient diffuser, areas of the display appear substantially brighter than other areas. This can be displeasing to the user and may make reading the display sometimes difficult. This problem can be minimized by adding more lamps but the chances for failures to occur increase proportionally. It would therefore be advantageous to use only one lamp for all the necessary illumination required by a hand held communication device while maintaining or improving the display illumination.
To achieve this, fiber optic cables, which can contain several strands of fiber optic material, would replace the incandescent lamps used for the display
illumination and visual alerts. The other ends of these cables would be directedi#to a common point. A single incandescent lamp would be mounted in such a manner as to direct the light in one direction towards the ends of the fiber o&c cables. A light switching means is placed between the incandescent lamp and the fiber optic cables. This switching me...