JP2575910B

A light (or an infrared ray) emitting member or a reflective (or an infrared ray reflective) medium (something like a reflective tape which reflects light in the caoxial direction when light is applied to it) is mounted at a predetermined position on an object to which an image is projected. The light emitting member or the reflective medium is caught in the coaxial direction of an image projecting unit by an (infrared ray) image pick-up means and video signals obtained by the (infrared ray) image pick-up means are binarized in the image processing unit, thereby a high luminous part of the light emitting portion or the reflected portion necessarily coming out on a binary image. A central value of a primary moment (so called a center of the figure) on the binary image including the high luminous point obtained by the above operation, is calculated on real time, and the calculated data are fed back to an electrically-driven driving portion of the image projecting unit, so that the image may be continually projected at the predetermined position. The electrically-drive turn table is adapted to automatically control the image projecting direction including the direction of light. Carrying out a series of the controls described above exactly, the image projecting apparatus projects the image by automatically tracking the position of the moving light emitting member or the reflective medium. Consequently, the image can be continually projected at the predetermined position, automatically tracking the moving object such as an airship or a balloon, so that it can be available as an effective advertizing medium or news medium.