A room-temperature-operated infrared (IR) image sensor with 64*32 infrared-sensitive MOS gates was developed by combining a pyroelectric thin plate with a Si charge-coupled device (CCD) by dielectric coupling. A pyroelectric plate is bonded to the Si CCD with an organic dielectric, and controls the Si surface potential of the MOS gate. The ability of the pyroelectric MOS gate to control the Si surface potential as a function of the IR signal is analyzed by taking account of both electrical charge and heat transfer. From this analysis, the design of the infrared sensing element is optimized. The pyroelectric materials used for the MOS gate were LiTaO/sub 3/ and PZT, and the organic dielectrics used were glycerin, di-n-butyl sulfone, nitroaniline, and P(VDF-TrFE). The basic characteristics of the pyroelectric gate of the CCD were obtained for several combinations of the pyroelectric and organic dielectric materials. >