Gaia CCD with the position of the special TDI gates overlayed in yellow. The charge injection structure is to the left and the serial register to the right. Only the three TDI gates closest to the charge injection structure are marked. Towards the serial register the spacing between gates is successively reduced by a factor of 2 and becomes too closely spaced for illustration. The image orientation follows the Gaia convention with the scan direction in the image area from left to right. The physical dimensions of each device are approximately 4.7 × 6.0 cm (AL × AC).