U.S. Philips Corporation

Alouisius W Korthout

Hermanus L Peek

Michael A Stekelenburg

Hendrik Heijns

Colm J Sweeney

The absence of a memory matrix in full frame CCD imagers renders it difficult to convert an image with a sufficiently high frame rate for displaying it again in a satisfactory manner on, for example, an LCD screen. To eliminate this disadvantage, an image is projected on a segment of the imaging matrix in an embodiment of the invention and, after the integration period, is stored in an adjoining, separately controllable segment which is used as a memory during the read-out while in the first segment a fresh image is received and converted into electric charge. During the transfer of the information from the first to the second segment, empty lines are formed between the lines containing information, in which empty lines compensation charge is formed during the charge storage which can be subtracted from the signals so as to compensate for the smear added to the signals during storage in the--exposed--second segment. The total number of lines can be limited in that signal lines are joined together or signal lines are drained off through the substrate. In a second embodiment, the charge pattern of the second segment may be transported back to the first segment again, which is used as a memory, while an image is received by the second segment. It is possible in this manner to convert and display a full frame with a comparatively high frequency.

Method of operating a CCD imager suitable for the implementation of such

A 3-phase charge-coupled imaging device is operated in the interlace mode. During integration, voltages are applied to the clock electrodes such that charge is integrated below the same set of electrodes each time. The signal charges of the first field are formed in that 3/4 portion of the charge in each picture element is augmented by 1/4 portion of the charge of the preceding picture element, while the signal charges of the second field are formed in that the 3/4 portion is augmented by 1/4 portion of the charge generated in the following picture element. These summations may be carried out in the sensor itself in that the charge packages are shifted to the left and right during integration. The flicker which is usually the result of interlacing is very strongly reduced in this way.

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Eindhoven, Netherlands

Alouisius W Korthout