Accurate measurement of ST and CCI of camera lens with double light paths

Abstract

The spectral transmittance (ST) and colour contribution index (CCI) are two important quality indexes of the colour camera lens. Automatic and accurate measurement of above indexes is imperative demand of factories which produce the colour camera lens. Because the instruments produced atpresent use single light path, they require long measuring time and are easily disturbed by voltage fluctuation and temperature variation so that the precision and stability are not idea. In order to improve the characteristics of the instrument, we have researched and produced the automaticmeasuring instrument with double light paths, whose precision and stability are higher than those of the same kind of instrument with single light path. This paper will discuss the following contents: the principle and adjusting technique for measuring ST and CCI with double light paths; the demodulating circuit and the automatic scanning circuit; the flowchart of program.