Illumination – Illuminated scale or dial – Edge illuminated modifier or light rod/pipe
Patent
1991-09-06
1993-12-21
Cole, Richard R.
Illumination
Illuminated scale or dial
Edge illuminated modifier or light rod/pipe
362 30, 362298, 362331, G01D 1128
Patent
active
052726010
ABSTRACT:
Improved backlighting of liquid crystal and other flat panel displays is accomplished by lighting the back of the LCD using lamps located at the ends of the LCD. The LCD is mounted over a channelized frame, and a light transmissive window covers each end of the channel, the combination forming a sealed LCD unit. The LCD unit is mounted in a panel which has reflectively-coated recesses on each side of the LCD unit containing incandescent lamps and opening in registry with the windows in the LCD. The windows are constructed of two back-to-back sheets of prism film whose function is to reject light impinging at greater than the critical angle of the film. The light from the lamps is thereby better distributed along the full width of the LCD, which eliminates bright and dark spots on the LCD. The LCD channel is provided with a centrally-located, raised luminaire to further diffuse light from the lamps in the center of the LCD. Placement of the lamps outside the LCD unit permits defective lamps to be replaced without opening the LCD unit which is normally sealed for environmental reasons. Provision of openings into the lamp recesses permits lamps to be replaced from the front panel without removing the electronics equipment of which the LCD is a part.
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3M/Optical Systems, T.I.R. Film (SOLF), Design Aid.
Gilmore, V. Elaine, Piping Light, Popular Science 1988.
3M/Scotchlamp Film application note and specifications, 3M, St. Paul, Minn.
Cole Richard R.
Hamann H. Fredrick
Murrah M. Lee
Quach Y.
Rockwell International Corporation
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