Abstract The interference patterns that would be recorded on a hologram from a complexly shaped surface such as the surface of an optical element or jet turbine blade, or the like, is calculated in a suitably programmed computer which may be coupled to an automatic plotter. The automatic plotter will then print the interference pattern which would be produced by projection of the pattern on the film in the form of dots of variable spacing or of different shading in order to produce the desired pattern. This printed pattern is then photographed with a high resolution film such as one capable of resolving four-hundred separate dots per millimeter of length, with this film serving as a hologram containing the synthesized interference pattern that represents the computed surface. The hologram or artificial optical template is then illuminated by a laser source so that a virtual image of the computed surface is produced. An object having a surface which is to be compared to the computed surface is then superimposed on the virtual image position so that an interference pattern is produced which describes the difference between the contour of the actual surface and the contour represented by the virtual image of the hologram template. The object may be a work piece which is to be surface eroded until it conforms to the desired pattern in which case the interference pattern is utilized to control the surface erosion operation.
A process of contouring a surface of a real object comprising the steps of programming a computer to control generation of a real pattern representing, substantially to mathematical accuracy, the uniquely characteristic interference pattern of an ideal surface contour that is to be provided on the surface of the real object, generating said real pattern, producing a hologram embodying said real pattern, exposing the hologram to a laser beam to superimpose a virtual image of the hologram upon a real image of the surface of the real object to develop an interference pattern between said virtual image and said real image and interferometrically monitoring the last-named interference pattern while removing material from the surface of the real object.
Claim 2
Dependent Claim
118 words
A process of contouring a surface of a real object comprising the steps of programming a computer to control generation of a real pattern representing, substantially to mathematical accuracy, the uniquely characteristic interference pattern of an ideal surface contour that is to be provided on the surface of the real object, generating said real pattern, producing a hologram embodying said real pattern, exposing the hologram to a laser beam to superimpose a virtual image of the hologram upon a real image of the surface of the real object to develop an interference pattern between said virtual image and said real image and interferometrically monitoring the last-named interference pattern while removing material from the surface of the real object.
Claim 3
Dependent Claim
48 words
A process in accordance with claim 1 wherein the generating step includes producing a printed pattern, wherein the producing step includes photographing the printed pattern to produce a photographic negative, and wherein the exposing step includes exposing the negative to a laser beam to produce the virtual image.
Claim 4
Dependent Claim
22 words
A process in Accordance with claim 1 wherein said real object is an optical element to be provided with a complex surface.
Claim 5
Dependent Claim
21 words
A process in accordance with claim 3 wherein said complex surface is to be aspheric and characterized by steeply sloping surfaces.
Claim 6
Dependent Claim
17 words
A process in accordance with claim 1 wherein material is removed by a beam of positive ions.
Claim 7
Dependent Claim
36 words
A process in accordance with claim 1 wherein the monitoring step includes automatically controlling the removal of material according to the preselected erosion pattern determined by the uniquely characteristic interference pattern of the ideal surface contour.
Claim 8
Dependent Claim
39 words
A process in accordance with claim 1 wherein material is removed by a beam of positive ions which is automatically controlled according to the preselected erosion pattern determined by the uniquely characteristic interference pattern of the ideal surface contour.