Method and apparatus for optical imaging using a small, flat, reflecting surface
Nilsson, Thomy H.
An image forming technique using a small, flat mirror is disclosed. A real, inverted image of an object is formed with infinite depth of field when the diameter of this mirror is between 0.15 and 0.4 millimeters. In smaller diameters, this forms a diffraction pattern image of an object. The optimal diameters depend on wavelength of the light and the distances involved.