Christopher Michael Lacey

US Patent:

7715017, May 11, 2010

Filed:

Dec 13, 2004

Appl. No.:

11/011295

Inventors:

Christopher Allen Lacey - San Diego CA, US

Assignee:

MicroPhysics Inc - Carlsbad CA

International Classification:

G01B 9/02

US Classification:

356507, 356485

Abstract:

An apparatus and a method for measuring very small separations between a transparent or semi-transparent first body and a second body, wherein one or more light sources produce light that is split into two distinct paths. One path is directed through the first body at two locations, one where it reflects from the interface at the separation to be measured, and another where the second body does not affect the reflection. The second path is directed at a frequency shifter, which shifts the frequency of the light. The two paths are recombined and interfereometric variations of intensity, substantially at the frequency of the shifter, are detected. The difference in phase between the measurement and reference areas with the second body not present is subtracted from the difference in phase between the measurement and reference areas with the second body present. The difference in differences yields the phase change that occurs when the second body is introduced. Using this phase change and the optical properties of the bodies and the medium between them, the separation is calculated.

US Patent:

20100128282, May 27, 2010

Filed:

Jan 20, 2010

Appl. No.:

12/690569

Inventors:

Christopher Allen Lacey - Rancho Santa Fe CA, US

Assignee:

MICROPHYSICS INC. - Carlsbad CA

International Classification:

G01B 11/02

US Classification:

356507

Abstract:

An apparatus and a method for measuring very small separations between a transparent or semi-transparent first body and a second body is disclosed. A light source produces light that is split into two distinct paths. One path is directed through the first body at two locations, one where it reflects from the interface at the separation to be measured, and another where the second body does not affect the reflection. The second path is directed at a frequency shifter. The two paths are recombined and interferometric variations of intensity are detected. The difference in phase between the measurement and reference areas with the second body not present, is subtracted from the difference in phase between the measurement and reference areas with the second body present. The difference in differences yields the phase change that occurs when the second body is introduced. The separation is calculated based on this phase change.

US Patent:

56381786, Jun 10, 1997

Filed:

Sep 1, 1995

Appl. No.:

8/522553

Inventors:

Christopher A. Lacey - San Diego CA
Kenneth H. Womack - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 1114

US Classification:

356369

Abstract:

An apparatus and method for measuring the space between a transparent member such as a disk, and reflective member such as a slider, by detecting a change of polarization of a reflected light beam. The apparatus includes a light source that emits a light beam. The light beam is circularly polarized and directed onto the disk and reflected off of the interface between the disk and the slider. The reflected light beam is split into four separately polarized beams by a beam splitter/polarizer assembly. The four light beams have varying intensities that are measured by photodetectors. Stokes parameters are computed from electrical signals that are generated by the photodetectors. The Stokes parameters correlate to the change in polarization of the reflected light beam. Ellipsometric parameters delta and psi are computed from the Stokes parameters. The thickness of the space and the complex index of refraction (n and K) of the slider are computed from the delta and psi parameters, typically by computing two separate sets of ellipsometric parameters at two different spacing thicknesses.

US Patent:

54869242, Jan 23, 1996

Filed:

Dec 22, 1993

Appl. No.:

8/172471

Inventors:

Christopher Lacey - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 902

US Classification:

356357

Abstract:

Light is focused on an interface between a transparent probe and a surface to be analyzed. The probe is lowered onto the surface using a computer-controlled actuator. Light reflected from the surface of the probe which is closest to the surface and the surface itself recombines, producing interference effects from the spacing between the probe and the surface over a 2-dimensional area. Since the shape of the probe in known beforehand, the profile of the surface can be readily calculated from the 2-dimensional measurement of the spacing between the probe and the surface. This surface profile indicates the roughness of the surface. The surface hardness and other surface properties can be measured by pressing the probe onto the surface. The contact load between the probe and the surface is detected by a load cell. The force with which the probe is being pressed onto the surface is measured using the load cell.

US Patent:

56710488, Sep 23, 1997

Filed:

May 17, 1995

Appl. No.:

8/446906

Inventors:

Christopher Lacey - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 902

US Classification:

356357

Abstract:

A slider is mounted to a rotary drive mechanism. The slider is loaded, i. e. , moved toward and positioned near a disk surface, by rotary movement of the rotary drive mechanism in a first rotary direction. Similarly, the slider is unloaded, i. e. , moved away from the disk surface, by rotary movement of the rotary drive mechanism in a second rotary direction which is the reverse direction of the first rotary direction.

US Patent:

56966539, Dec 9, 1997

Filed:

Dec 13, 1996

Appl. No.:

8/766898

Inventors:

Christopher A. Lacey - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G11B 555
G11B 2108
G01J 102

US Classification:

360104

Abstract:

A tooling fixture that holds a head gimbal assembly (HGA) of a hard disk drive within a piece of test equipment. The tooling fixture includes a plurality of pads that extend from a top surface of a chimney. The HGA has a slider that is mounted to a flexure arm. The flexure arm extends from a base plate of the HGA. The base plate has a swage mount that is inserted into a corresponding aperture of the chimney when an operator loads an HGA into the tester. The pads of the chimney support the base plate and the HGA. The base plate is typically clamped onto the chimney by a spring biased clamp. The HGA is moved adjacent to a rotating disk of the tester. The pads provide a reliable contact surface that improves the repeatability of the HGA positioning which in turn can improve the tester.

US Patent:

58087362, Sep 15, 1998

Filed:

Sep 24, 1996

Appl. No.:

8/718899

Inventors:

Kenneth H. Womack - San Diego CA
Carlos A. Duran - San Diego CA
Christopher A. Lacey - San Diego CA

Assignee:

Phase Metrics, Inc. - San Diego CA

International Classification:

G01J 102

US Classification:

356243

Abstract:

A calibration medium that is used to calibrate a flying height tester which measures the gap of an air bearing formed between a magnetic recording head and a substrate. The medium contains a first ridge and a second ridge that extend from an underlying substrate. The ridges may be coated with a reflective material. A flying height tester can be calibrated by measuring light reflected from each ridge. The ridges have varying thicknesses so that the calibration medium will produce multiple data points.

US Patent:

57777403, Jul 7, 1998

Filed:

Feb 27, 1997

Appl. No.:

8/807669

Inventors:

Christopher A. Lacey - San Diego CA
Kenneth H. Womack - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 902

US Classification:

356357

Abstract:

An apparatus and method for measuring the topographic profile of a reflective member having an index of refraction. The apparatus comprises a first optical system that reflects a light beam from the reflective member and detects the reflected light beam. A second optical system directs the light beam to interfere with the reflected light beam and detects the resulting interference pattern. A processor coupled to the first optical system and the second optical system computes the index of refraction of the reflective member from the detected reflected light beam and provides the topographic profile of the reflective member from the index of refraction and the interference pattern.