changing the projection light path of the projection lens group, so that the projection light containing the encoded grating image information is emitted to the first plane mirror on the inner surface of the oral cavity;
Changing the projection light path of the projection lens group so that the projection light containing the encoded grating image information is emitted to the first plane mirror on the inner surface of the oral cavity;
A first plane mirror that changes the projection light path of the projection lens group to make the projection light containing encoded raster image information emit to the inner surface of the oral cavity;