A pocket-sized two-dimensional image projection device adapted to a portable device is invented. The pocket-sized two-dimensional image projection device projects two-dimensional image on a projection surface with arbitrary profile and arbitrary distance from the projection device, and arbitrary attitude about the projection device. The position, profile, and attitude of the projection surface about the projection device can be arbitrary because the projection surface is not embodied in the projection device to reduce size of the device. Each micromirror array lens has the ability of scanning and focusing on the projection surface. The focusing on the projection surface can be achieved by automatic focusing function of micromirror array lens. Therefore, an in-focused two-dimensional image can be displayed on arbitrary projection surface. Also, this invention makes a brighter and less power consuming display device, which give an advantage for the portable device application.