The autofocus control system of a projector includes a projector and an imaging unit. The projector includes a lens actuator that drives a projection lens, and a first controller that projects a first or a second pattern image selected, the second pattern image being mesh-shaped more coarsely than the first pattern image. The imaging unit includes an imaging part that images the first or second pattern image selected to generate imaged data, a user interface part that acquires a zoom magnification, and a second controller that transmits a focus control command to the first controller based on the imaged data. The second controller transmits to the first controller, an instruction signal for selectively projecting the first pattern image when the zoom magnification is smaller than a given magnification, and an instruction signal for selectively projecting the second pattern image when the zoom magnification is the given magnification or larger.