A object sensor system for a swing door includes swing-side and approach-side sensors. Each of the sensors includes light-emitters and light-receivers which are mounted on a swing door. The light-emitters emit light toward a floor, and the light-receivers receive the light as reflected from the floor. The light emitted and received provides an object sensing zone which has a rectangular shape on the floor having a width equal to or larger than the width of the door. The sensing zone includes a main sensing area closer to the door and an auxiliary sensing area extending along the main sensing area. The auxiliary sensing area is disabled when the door moves.