Image sensor for still or video photography
View Patent ↗An image sensor includes a plurality of vertical CCDs; first HCCD receiving charge packets from even numbered vertical CCDs; and a second HCCD receiving charge packets from odd numbered vertical CCDs; wherein four charge packets are summed together from the first HCCD, and four charge packets are summed together in the second HCCD such that the summing process in the second HCCD begins one or two charge packets spatially after the first charge packet of the four charge packets summed in the first HCCD.
1. A method for summing charge packets generated in an image sensor that includes a plurality of vertical charge-coupled devices, a first horizontal charge-coupled device (HCCD), and a second horizontal charge-coupled device (HCCD) electrically connected to the first HCCD, the method comprising:
transferring a line of charge packets from the plurality of vertical charge-coupled devices to the first HCCD, wherein the charge packets represent two different colors;
transferring the charge packets representing only one color from the first HCCD to the second HCCD;
summing together two charge packets in the second HCCD by shifting every other charge packet three columns and the remaining charge packets one column within the second HCCD;
summing together two charge packets in the first HCCD by shifting every other charge packet two columns within the first HCCD;
shifting the summed charge packets in the second HCCD two columns so that the summed charge packets in the first HCCD are in the same column as the summed charge packets in the second HCCD;
summing together on a floating diffusion connected to the first HCCD two summed charged packets by reading out summed charge packets from the first HCCD; and
summing together on a floating diffusion connected to the second HCCD two summed charged packets by reading out summed charge packets from the second HCCD.