Line-transfer image sensor operating in the double-reading mode

A solid-state image sensor for 625-line TV cameras has been improved for a novel method of implementation. The sensor\´s "line-transfer" organization uses conductive buses to transfer photoelectric information in parallel along the vertical direction. The information is then extracted by a CCD output register. A particularly interesting feature of this organization is its ability to separate the useful signal from parasitic signals, such as smearing, through a double reading of the vertical buses. Double reading under good conditions calls for a specific design which will first be described before detailing the double-reading process. The paper then analyzes the bus-reading mechanism and its efficiency, a key parameter for the main electrooptical characteristics. Finally, experimental results are presented and should demonstrate the interest of this sensor organization.