A projector includes a projection lens, an optical engine, and a light device. The light device has a lighting axis and includes a movable frame, two light sources fixedly disposed on the movable frame, and a driving part kinematically connected with the movable frame. The driving part is disposed in front of the two light sources. The driving part moves the movable frame such that the two light sources moves simultaneously so as to selectively make one of the two light sources emit light along the lighting axis, which avoids single light source operating for long time. The optical engine is disposed close to the light device and has a light entrance axis. The light entrance axis coincides with the lighting axis. The optical engine includes a digital micromirror device that modulates light from the light device to be projected out the projector through the projection lens.