Lockheed Martin Corporation

Fairchild Camera and Instrument Corp.

Loral Fairchild Corporation

Kenneth A Hoagland

Dynamic range extension (DRE) is achieved in CCD imagers with charge overflow structures by varying the potential V,on the gate electrodes of the pixel signal charge wells during charge integration. The wells are formed to function with the charge overflow structures, e.g., vertical overflow drains, VODs, a) to control the signal charge spreading due to illumination overload and/or b) as a means for the control of signal integration time. Two different V,levels are applied to the gate electrodes, the lower of the two levels V,-LOW is applied for a long duration and the higher level V,-HIGH is applied for a shorter duration during charge integration. At low levels of incident illumination on the CCD surface, charge signals are integrated without saturation, but, at levels of very intense illumination during the period with voltage V,-LOW on the gates, the pixel wells will saturate before the end of charge integration, resulting in the vertical overflow drain (VOD) operating to dump excess charge to the substrate. With the subsequent imposition of V,-HIGH for a short time period near the end of the integration interval, pixel well saturation is delayed and signals corresponding to high intensity are not lost. Consequently, imposing V,-HIGH for a short time period near the end of the integration interval (a) increases pixel charge storage capacity and (b) shortens the exposure time, which combination allows high intensity signal information to be integrated without loss by saturation.

Dynamic range extension of CCD imagers

An apparatus and method for allowing television systems using solid-state image sensors to be compatible with a multiplicity of television standards. Scenes conforming to a standard which specifies a format aspect ratio or a specific number of active scan lines per frame are input into the anamorphic television system. The anamorphic television system modifies these scenes to take optimum advantage of the resolution of the solid-state image sensor. The anamorphic television system alters the dimensions of the scene along the horizontal and/or vertical axis so that the scene conforms to the format aspect ratio of the solid state image sensor and/or to the number of active scan lines per frame as specified in the applicable standard. The solid-state image sensor converts the optical information into an electrical signal. This electrical signal is retrieved from the solid-state image sensor by timing circuitry. The retrieved electrical information is converted into a composite video signal which is then displayed on the display monitor. The original proportionality of the scene is recaptured by altering the vertical and/or horizontal height controls on the display monitor and/or by altering the rate at which the information is retrieved from the image sensor and displayed on the display monitor.

System and method for using an anamorphic fiber optic taper to extend

A video-signal-generating system comprises a pair of similar charge-coupled area-image-sensing devices, each comprising a two-dimensional array of photosensor sites arranged in rows and columns, each site being effective to produce a charge packet in response to illumination incident thereon, a charge-detection output circuit capable of producing an output signal varying with the magnitudes of successive charge packets in sequence, and a plurality of charge-storing sites located intermediate the photosensor sites and the charge-detection circuit for effecting the orderly transfer of charge packets from the photosensor sites in sequence to the charge-detection circuit. The system also includes an optical system for simultaneously imaging a scene to be reproduced on each of the charge-coupled area-image-sensing devices where each device is positioned with respect to corresponding image points such that photosensor sites of one of the devices are offset along row and column directions within the image plane from corresponding photosensor sites of the other device. One example described comprises two image-sensing devices with the offset made equal to one row spacing of photosensor sites in one direction and one-half column spacing of photosensor sites in the other direction. The system also includes means for combining the output signals of the output circuits of the image-sensing devices to provide a video signal for reproduction.

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Smithtown, NY, United States of America

Kenneth A Hoagland