An imaging device includes at least a first group of pixels. A driver block is configured to generate at least two shutter signals, each having on-phases periodically alternating with off-phases. The shutter signals might not be in phase. The imaging device may have an optical shutter that is partitioned in two or more parts, or a set of two or more optical shutters. The shutter parts, or the shutters, may receive the shutter signals, and accordingly open and close. A design of the driver block requires reduced power, which is highly desirable for mobile applications. Moreover, 3D imaging may be implemented that uses various time-of-flight configurations.