An array of M.times.N thin film actuated mirrors for use in an optical projection system, includes an active matrix, an array of M.times.N actuating structures, an array of M.times.N mirror layers and an array of M.times.N supporting members. Each of the actuating structures includes a first a second and a third identically structured actuating parts, each of the actuating parts having at least a motion-inducing thin film layer, a first and a second electrodes. The first electrode from each of the actuating parts is connected to ground, thereby serving as the bias electrode, and the second electrode thereof functions as the signal electrode. Each of the mirror layers is provided with an odd number of tab portions, each of the tab portions being partially separated from the neighboring tab portions by a dividing slot therebetween. The second actuating part is secured to the middle tab portion and the first and third actuating parts, to the two next nearest tab portions, located at either side of the middle tap portion, respectively, such that when the actuating parts in each of the actuating structures deform in response to an electrical signal, the tab portions with the actuating parts attached thereto tilt while the remainder of the mirror layer stays planar, thereby allowing all thereof to reflect light beams, resulting in an increased optical efficiency.