One embodiment of the invention discloses projector circuit boards comprising an image receiving terminal, a central processing unit, a motor driving module, a DMD and a DMD control module. The image receiving terminal receives an image signal and transmits the received image signal to the central processing unit. The central processing unit processes the received image signal. The motor driving module drives a motor on the basis of the processed image signal to rotate a color wheel to generate a colored beam. The DMD, comprising a plurality of micro-mirrors, is used in reflecting the colored beam, transforming the colored beam into an image beam, and transmitting the image beam to a projection lens to project an image. The rotation angles of the micro-mirrors are controlled by the DMD control module coupled between the central processing unit and the DMD. The projector circuit board is perpendicular to a light path of the projection lens.