An image sensor controller and methods achieve faster image reading speeds by controlling the frequency of image sensor transfer clocks φ1, φ2 in accordance with the particular output period. Such an image sensor controller includes a drive controller that supplies to a transfer section of the image sensor transfer clocks φ1, φ2 whose clock frequency during dummy pixel output periods is faster than it is during an effective pixel output period, or whose clock frequency during non-reading pixel output periods is faster than it is during a reading pixel output period. A pattern selector selects among clock patterns in a table for setting φ1, φ2 according to the output periods of the image sensor. Even when the clock frequency of φ1, φ2 changes, a transfer clock ADCK signal can be supplied at a constant clock frequency to an A/D converter.