In the related projector, it emits the light beam from optical valve image to an ultrasonic media with some incidence angle; then, the beam crosses through the media and alternative generates the diffraction light with a first direction and the transmitted light with second direction, and this invention can enhance image resolution by two lights. Wherein, it arranges the piezoelectric material on one end of the media, and a high-frequency oscillation forces the piezoelectric material to generate ultrasonic wave. |