An exemplary measuring apparatus includes a base, a table, a light blocking piece, a sensor, a luminance meter, a drive assembly, and a controller. The table defines a first elongated slot. A light guide plate is arranged on the table with a central portion of a bottom surface thereof exposed to the...http://www.google.com.au/patents/US7924417?utm_source=gb-gplus-sharePatent US7924417 - Luminance measuring apparatus
