A monitoring apparatus and method for measuring light output gradient of a faceplate
panel includes a top plate having a center detector and a plurality of corner detectors
mounted along a major surface thereof. Lenses are optically coupled to a respective
detector, and radiometers are electrically coupled to a respective detector. A
bottom plate spaced apart from the top plate has a plurality of light outputs mounted
along a major surface thereof and positioned to be opposite each detector. A light
source is optically coupled to each light output through a splitter. A computer
is electrically coupled to the light source for receiving feedback therefrom and
for controlling the light source. The computer is also electrically coupled to
each radiometer for recording data therefrom.
During monitoring, a faceplate panel having a matrix applied thereto is accurately
positioned between the top and bottom plates such that the center detector is located
approximately above the center of the faceplate panel. Light is passed from the
light sources through the faceplate panel to the detectors under control of the
computer. The light output measurements at each detector are recorded by the computer
and calculation is made of a light output gradient based upon a comparison of the
light output at the center detector to the light output at the corner detector.
