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A comprehensive illuminator has been designed and constructed for complete test or characterization of CCD and CMOS image sensors. By changing the position of a multi-grating turret of a Czerny-Turner type monochromator from a grating to a highly reflective mirror, two modes of operation can be achieved. Monochromatic flux is generated when the turret is set to the normal grating position and broadband light is generated when the turret is set to the mirrored position. The flux is directed through an aperture and collimated to form a uniform, wide-field, monochromatic or broadband source. An in-situ calibrated detector along with two automated filter wheels is used to monitor monochromatic irradiance, illuminance and color temperature. Testing of image sensors for parameters such as well capacity, sensitivity and linearity can be made for broadband illumination whereas spectral responsivity and quantum efficiency measurements of the image sensor can be made over the wavelength range of 380 to 800 nm. An in-situ calibrated detector is used for absolute light calibration in both intensity and correlated color temperature. Two filter wheels and high-speed shutter have been integrated into the light path of the monochromator to enable the automatic control of output light intensity, shape and color. Stages are also provided for slide pattern projection and aperture control. This illuminator is able to output a 2'-diameter beam with less than 5% non-uniformity. The maximum broadband light output is close to 400 lux, and has 90 intensity control steps. The spectral test mode can cover visible wavelength range with resolution up to 0.5 nm. Software has been configured to do automatic mode change and testing. By designing standard image sensor illuminator functionality into a spectroradiometer, we have achieved a compact, multi- functional, automated, low-cost illuminator for image sensor testing and characterization. The option of adding a fiber optic to the system allows easy integration of the illuminator into any laboratory or production equipment such as a prober station or a packaged parts handler.
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