The effect of direct x-ray on CMOS APS imager for industrial application

Abstract

In this paper, we presented the effect of direct X-ray after scintillator on the CMOS APS imager using modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). 50 kVp of X-ray tube voltage at the SID of 300 mm were set with continuous made micro-focus X-ray machine on the assumption for industrial application such as PCB inspection. Lanex screen coupled CMOS APS imager was irradiated for long-term. From the experimental results, MTF and also DQE were degraded exponentially because of reduction of dynamic range caused by dark current or dark signal increase. For a given scintillator and an exposure condition, the degradation of image performance can be expected in case that the CMOS APS be used as a basic sensor array.