Inventors:
Gang Liu - Novi MI
Mark H. Schwartz - Orchard Lake MI
Assignee:
Analog Technologies, Inc. - Farmington Hills MI
International Classification:
G01N 2116
Abstract:
A laser-based optical inspection system is provided for detecting and measuring surface imperfections and warpage conditions in an optical information storage disk either during its manufacture or afterwards. The optical inspection system includes a light source, a rotatable mirror for directing a source beam from the light source along a radial line on the surface of the disk, a convex lens positioned between the mirror and the disk for focusing the source beam at the surface of said disk, and a photodetector for registering a beam being reflected from the surface of said disk, such that the reflected beam is indicative of surface imperfections in said disk. In addition, an electronic processor and controller are connected to the photodetector for processing its registered beam signals and for determining if the disk surface imperfections exceeds specified tolerances. Furthermore, the processor may be used to control other system components, including the light source, the actuator device for rotating the mirror, and the drive motor for rotating the disk during the inspection process. These results about the warpage and any surface imperfection of the disk can be displayed on the monitor of the computer to inform the machine operator as well as sent to other related manufacturing machines for further usage.