Method and apparatus for position sensing

Details Method and apparatus for position sensing Method and apparatus for position sensing

1996-12-06

1998-08-18

Font, Frank G.

Optics: measuring and testing

By particle light scattering

With photocell detection

356363, 356401, 250548, G01B 902

Patent

active

057964831

ABSTRACT:
Using an LIA alignment sensor, consecutive sensings of a reference-mark position are taken. I(.omega.), the power spectrum of the fluctuations of these sensings in a time period is computed. I'(.omega.), the power spectrum of the averaged fluctuations for an averaging time .DELTA.T that changes between two different measurement times .DELTA.T1 and .DELTA.T2 is then computed. The dispersion of the data averaged during this averaging time .DELTA.T matches the integral of the power spectrum I'(.omega.). The time period during which the value of the integral of the power spectrum I'(.omega.) reaches its lowest value is used as the measurement time of the position based on the beat signal obtained by the alignment sensor.

REFERENCES:
patent: 4710026 (1987-12-01), Magome et al.
patent: 4856905 (1989-08-01), Nishi
patent: 5151750 (1992-09-01), Magome et al.

Affiliated with

Also associated with

Rating

Method and apparatus for position sensing 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 position sensing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for position sensing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1119789