A projection display apparatus has a beam controller provided on the optical axis of an optically-modulated linearly-polarized beam, to allow the beam to travel therethrough to reach a screen or cut off the beam, under control by a control signal. The controller, has driving zones on which the beam is incident. The zones are provided in a direction corresponding to a vertical scanning direction of pixels of a liquid crystal display device installed in the display apparatus, for optically modulating a linearly polarized beam. The controller is driven per driving zone in a specific zone order at a timing of vertical scanning of the pixels under control by the control signal generated based on a vertical synchronization signal detected from the input signal. The optically modulated beam is allowed to travel through the controller or cut off when incident on the zones at the timing of the vertical scanning.