Page 204 - The Art and Science of Analog Circuit Design

Jim Williams

particularly useful in evaluating display (as opposed to simply the lamp)
luminosity under various drive conditions. The calibrated output permits
2
reliable correlation with customer results. The light tight measuring head
allows evaluation of emittance evenness at various display locations. This
capability is invaluable when optimizing lamp location and/or ballast
capacitor values in dual lamp displays.
Figure 11-B2 shows the photometer in use evaluating a display.

2. It is unlikely that customers would be enthusiastic about correlating the "brights" units produced
by the aforementioned glometer.

Figure 11-B2.
Apparatus for calibrated photometric display evaluation. Photometer (upper right) indi-
cates display luminosity via sensing head (center). CCFL circuit (left) intensity is con-
trolled by a calibrated pulse width generator (upper left).

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