A photosensor element suitable for incorporation into charge-coupled device (CCD) imaging arrays in which the charge injected into the CCD is proportional to the logarithm of incident light intensity is presented. The photosensor element consists of a photodiode directly coupled to a two-stage MOSFET common source amplifier. This element occupies an area of 25 × 100 μm and is arranged so that it could be incorporated into a linear CCD imaging array having a period of 25 μm. A logarithmic response is measured over a 68.6-dB range of incident light intensity with a sensitivity of 55 mV/decade of light intensity.
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