IMAGE PROJECTOR AND IMAGE PROJECTING METHOD

In an image projection on a screen, an image projection apparatus improves the safety of entry into a projection region by the human body and does not bring about the increase of complexity of the configuration thereof owing to the improvement of the safety. A monitoring area is regulated on the outside of the projection area (3) of the screen (2). A detection wave such as infrared rays is emitted from a detection wave source (1c) of the image projection apparatus (1). A reflection wave from the monitoring area is detected by reflection wave detection means (1d) such as a CCD sensor. Whether the human body or an obstacle enters the monitoring space, which is surrounded by a detection wave (4) between the main body unit of the image projection apparatus (1) and the screen (2), or not is detected. Once the entry is detected, the intensity of the radiation light traveling toward the projection area (3) is reduced or cut off according to the situation or the degree of the entry.