A brightness level detector detects a brightness level of the digital imaging signal for each of the plurality of pixels. A shading detector sets a group of pixel regions distant from each other in a horizontal direction in the imaging element and then detects whether or not shadings are generated in the analog imaging signal based on a difference between the brightness levels of the group of pixel regions. A timing adjuster adjusts a phase of a peak sample pulse for detecting a peak level of the analog imaging signal, a phase of a reference sample pulse for detecting a signal level used as a reference in the correlated double sampling executed when the digital imaging signal is generated and a phase of a horizontal transfer pulse in the imaging element based on outputs of the brightness level detector and the shading detector.