The RELCAM an optical transparent sensor for geometry alignment and monitoring systems

The RELCAM (for Reflected Light Camera Monitor), a new transparent photo-sensor is described. It is based on the reflected light picture monitored by a miniature video camera with CMOS IC pixel photo-sensor. Prototype investigations show that an intrinsic r.m.s. value of sigma sub r sub e sub s sub . = 0.5 mu m (resolution FWHM = 1.2 mu m), and a stability better than 0.8 mu m per angle in temperature can be achieved. The linearity function over the full active surface of the sensor has been measured, and method for its correction is proposed.