Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrometer
Patent
1997-01-30
1999-04-27
Turner, Samuel A.
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrometer
3562372, G01B 902
Patent
active
058984992
ABSTRACT:
A system is disclosed for detecting local surface discontinuities in magnetic data storage disks. The system includes a spindle that rotatably supports a magnetic disk being tested. An interferometer generates a laser beam which is guided through an optics assembly supported above the magnetic disk, for linear movement radially of the disk. The combined radial and linear movement causes the laser beam to trace a spiral scanning path on the disk surface. The disk surface scatters the laser energy, a portion of which is returned to the interferometer and caused to interfere with a reference beam. The resulting interference intensity fluctuates in response to changes in the optical path length, thus measuring topographies of the discontinuities. A discontinuity recognition triggering pulse can be positioned in time with respect to indexing pulses, to identify the location of the associated discontinuity radially and angularly of the disk. The triggering pulses limit the storage of scanned surface data to the part of the data that locates and characterizes discontinuities exceeding a predetermined size threshold.
REFERENCES:
patent: 4832487 (1989-05-01), Mikuaiya et al.
patent: 4844616 (1989-07-01), Kulkarni et al.
patent: 5389794 (1995-02-01), Allen et al.
patent: 5661559 (1997-08-01), Baezoczky et al.
"The Gaussian Beam", Fundamentals of Photonics, Saleh, et al, pp. 81-87, 1991.
Niebuhr Frederick W.
Seagate Technology Inc.
Turner Samuel A.
LandOfFree
Method and apparatus for detecting surface discontinuities based does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for detecting surface discontinuities based, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for detecting surface discontinuities based will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-688820