US 4,391,520 A · Technique for optical alignment of a workpiece

Abstract

A technique for aligning a surface of a workpiece with respect to a positioning ring attached to a holder supporting the workpiece comprises mounting the holder on an alignment platform adjacent a positioning block attached thereto for holding the positioning ring in a predetermined position. The holder is adapted to rotate the workpiece, with respect to the positioning ring, about a first axis, and the alignment platform is supported by a table. The surface of the workpiece is exposed to an incident light beam, whereby the incident beam is reflected from the surface, as a reflected beam, onto a screen along a path of alignment marks disposed thereon. The surface is then rotated about the first axis to change the location where the reflected beam strikes the screen, whereby the surface is properly aligned with respect to the positioning ring when the reflected beam strikes a particular location on the screen.

Claims21

Dependent claims

A method of aligning a surface of a workpiece with respect to a positioning ring attached to a holder supporting said workpiece, said holder adapted to rotate said surface, with respect to said positioning ring, about a first axis, comprising the steps of:

mounting said holder on an alignment platform adjacent a positioning block attached thereto for holding said positioning ring in a predetermined position, said alignment platform being supported by a table,
exposing said surface to an incident light beam, whereby said incident beam is reflected from said surface, as a reflected beam, onto a screen along a path of alignment marks disposed thereon,
revolving said positioning block, with respect to said alignment platform, about said first axis, whereby the point on said surface where said beam strikes remains substantially fixed in space, and
rotating said surface about said first axis to change the location where said reflected beam strikes said screen, whereby said surface is properly aligned with respect to said positioning ring when said reflected beam strikes a particular location on said screen.

1 more element

Apparatus for aligning a surface of a workpiece with respect to a positioning ring attached to a holder supporting said workpiece, said holder adapted to rotate said surface, with respect to said positioning ring, about a first axis, comprising:

an alignment platform having a positioning block attached thereto, said block adapted to hold said positioning ring in a predetermined position when said holder is mounted on said platform adjacent said block, said alignment platform being supported by a table,
a light source positioned so that a beam of light emanating therefrom strikes said surface as an incident beam and is reflected therefrom as a reflected beam,
a screen having a path of alignment marks thereon, said screen positioned so that said reflected beam strikes said screen along said path, and
means for revolving said positioning block, with respect to said alignment platform, about said first axis, whereby the point on said surface where said beam strikes may remain substantially fixed in space.

1 more element

Dependencies are inferred from the claim text.

Technique for optical alignment of a workpiece

Life of this patent

Technique for optical alignment of a workpiece

Life of this patent

Abstract

Claims21