An apparatus for forming an image on a curved diffusive surface comprises an image source for providing image-bearing light along an axis, a relay lens for directing the image-bearing light toward the curved diffusive surface, and, a field lens for redirecting off-axis image-bearings light toward the center of curvature of the curved diffusive surface. The deposited precursor is cured by electron-beam, infrared-light, visible-light, or ultraviolet-light radiation, as most appropriate for the particular material being deposited. The pawl has a triangular engagement tooth that is inserted into a tooth groove of the ratchet, and a second side end surface facing the non-locking surface is covered with a synthetic resin except a tip portion of the engagement tooth. The survey tool is maintained in a sleeping mode while drilling is undertaken, and activated to provide position data as the drill string is progressively withdrawn from the actual hole path. The retrieved date or range of dates may then be displayed based in the date request’s contextual information. , the flying height can be controlled so that the flying height becomes low at low temperatures and high at high temperatures, while maintaining the uniformity of the profile of the flying height of the magnetic head slider from the inner periphery to the outer periphery of the magnetic disk.