A projection apparatus for optical systems such as a projection type microscope or the like, which is adapted to project an image of a sample disposed on a movable stage onto a television monitor screen and display it thereon, and which comprises an image sensor composed of a charge transfer element including photosensitive elements aligned with a picture element and operative to receive the image of the sample to be projected; a driving circuit for scanning the image sensor; a television monitor for displaying a video signal obtained from the image sensor when it is scanned by the driving circuit; a memory device for storing the television signal; a stage movement detecting circuit for detecting the movement of the stage; a timer circuit for generating a signal everytime a given time elapses; and a drive control circuit device, when the stage is moving, becomes operative to operate the driving circuit on the basis of the output from the stage movement detecting circuit so as to scan the image sensor everytime the stage moves for a given distance and which, when the stage is stationary, becomes operative to operate the driving circuit on the basis of the signal from the timer circuit so as to scan the image sensor everytime a given time elapses, thereby normally displaying the image of the sample on the television monitor.