Patent ID: 8294802

Claim:
A charge-coupled device (CCD) image sensor comprising: an array of pixels each comprising a photodectector for conversion of incident light into electrical charge; electrically connected to the array of pixels, a horizontal CCD channel region comprising a plurality of shift elements for receiving change from the array of pixels and transferring the charge out of the array for conversion into an image each shift element comprising a plurality of phases; and associated with each shift element, a distinct overflow drain electrically connected to only one phase of the shift element, the phase being a drainable phase comprising (i) a first region proximate the array of pixels and (ii) a second region proximate the overflow drain, wherein a channel width of the drainable phase in the second region is narrower than a channel width of the drainable phase in the first region, the narrower channel width in the second region forming a potential barrier having a height selected to prevent charge blooming from the drainable phase into a component other than the overflow drain to which the drainable phase is connected.