Michael Ann Nahum, 592826 Fairview Ave E, Seattle, WA 98102

6335618, Jan 1, 2002

Oct 5, 1999

09/412789

Michael Nahum - Kirkland WA

Mitutoyo Corporation - Kawasaki

G01B 702

32420717, 32420724, 34087032, 336 45, 341 15

A high-accuracy inductive absolute position transducer system has two members movable relative to each other and includes an amplitude modulating transducer including flux modulators of progressively varying properties. The amplitude modulating transducer includes a transmitter winding and at least one set of receiver windings. An amplitude modulating transducer has a plurality of flux modulator zones distributed along the measuring axis. Flux modulators are formed in at least some of the flux modulator zones. The properties of different flux modulators are varied so as to generate varied flux. A signal generating and processing circuit is connected to the transmitter winding. The flux modulators modulate the inductive coupling based on the relative position between the read head member and the scale member.

6365912, Apr 2, 2002

Mar 6, 2001

09/719796

Norman Ewart Booth - Oxford, GB
Joel Nathan Ullom - Cambridge MA
Michael Nahum - Cambridge MA

Isis Innovation Limited - Oxford

H01L 2906

257 39, 257 30, 257 32, 257 36

A superconductive tunnel junction device in which quasiparticles in a superconductive region (S ), relax into a normal metal trap (N ) releasing their potential energy in electron-electron interactions to increase the number of excited charge carriers in the trap. The excited charge carriers tunnel through an insulating tunnel junction barrier (I ) into a second superconductive region (S ). The quasiparticles in the first superconductive region are formed either by absorption or energetic particles/radiation or by injection by charge carriers tunneling in from a base region which can be of normal metal (N ) or superconductor (or both) of semiconductor. The current from the trap to the second superconductor is higher than that out of the base region thus providing current amplification. The device can thus form a three terminal transistor-like device. It can be used as or in particle/radiation detectors, as an analogue signal amplifier, microrefrigerator or digital switch.

6487787, Dec 3, 2002

Aug 3, 2001

09/921727

Michael Nahum - Kirkland WA
Patrick H. Mawet - Snohomish WA

Mitutoyo Corporation - Kanagawa-ken

G01B 714

33706, 33702

A system and method for determination of error parameters for performing self-calibration and other functions in a transducer. The method utilizes the minimum and maximum values of the output signals of the transducer. To obtain these values, the output signals are measured at various times according to the sample timing, as the read head is scanned relative to the scale. The offset for each phase is determined to be equal to the average between the maximum and minimum voltages. The signal amplitudes are equal to the difference between the maximum and the minimum voltages, divided by two. By comparing the amplitude for each phase, the amplitude mismatch is found. The phase relation error may be determined by first removing the amplitude mismatch and the offset errors from each phase, and then comparing the relative amplitudes of the two signals at a given point in relation to what they ought to be with no phase relation error. The described method provides a fast calibration method which requires a minimum amount of data, and which can be automatically run in a background mode without inhibiting normal transducer operation.

6525530, Feb 25, 2003

Nov 28, 2000

09/722579

Bjorn Jansson - Snohomish WA
Michael M Nahum - Kirkland WA

Mitutoyo Corporation - Kawasaki

G01B 714

32420717, 32420716, 331117 R, 331167, 455 41

A drive circuit for driving the transmitter windings of an inductive position transducer includes an oscillating power source. A resonator section is connected to the power source. The resonator section includes an impedance transforming section, a transmitter winding of the inductive position transducer, and feedback loops which cause the power source to oscillate at the resonator frequency. The resonator operating frequency and the load impedance imposed on the power source by the resonator can be independently selected. In various exemplary configurations of the drive circuit, the resonator operating frequency adapts to variations in the impedance of the transmitter windings. The drive circuit is particularly well-suited for driving low-impedance and/or miniaturized inductive position transducers with enhanced efficiency and accuracy. In various exemplary configurations of the drive circuit, the peak operating voltage of the transmitter windings can exceed the power supply voltage.

6642506, Nov 4, 2003

Jun 1, 2000

09/584264

Michael M. Nahum - Kirkland WA
Karl G. Masreliez - Bellevue WA

Mitutoyo Corporation - Kawasaki

G01D 534

25023113

A speckle readhead includes a light source that outputs light towards an optically rough surface. Light scattered from this surface contains speckles. The scattered light is imaged onto an image detector, captured and stored. Subsequently, a second image is captured and stored. The two images are repeatedly compared at different offsets in a displacement direction. The comparison having the highest value indicates the amount of displacement between the readhead and the surface that occurred between taking the two images. An optical system of the readhead includes a lens and an aperture. The aperture can be round, with a diameter chosen so that the average size of the speckles is approximately equal to, or larger than, the dimensions of the elements of the image detector. The dimension of the aperture in a direction perpendicular to the direction of displacement can be reduced. Thus, the imaged speckles in that direction will be greater than the dimension of the image detector elements in that direction.

6664535, Dec 16, 2003

Jul 16, 2002

10/195422

Michael Nahum - Kirkland WA
Benjamin K. Jones - Seattle WA
Avron M. Zwilling - Redmond WA

Mitutoyo Corporation - Kawasaki

G01D 534

25023114, 250566, 356617

An absolute position-sensing device is usable to measure the relative position of two elements. An absolute scale includes an integrated track extending along a measuring axis of the scale. The integrated track includes a plurality of periodic portions interleaved with a plurality of non-periodic portions. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along the measuring axis than the length of the periodic scale elements. The offset of the periodic-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

6781694, Aug 24, 2004

Sep 13, 2002

10/242351

Michael Nahum - Kirkland WA
Benjamin K. Jones - Seattle WA
Patrick A. Renalds - Bothell WA
Avron M. Zwilling - Redmond WA
Kim W. Atherton - Kirkland WA

Mitutoyo Corporation - Kawasaki

G01N 2125

356420, 356421, 382312, 235494

An absolute 2D position-sensing device is usable to measure the relative position of two elements. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a plurality of periodic portions interleaved with a plurality of non-periodic portions along each axis. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along each measuring axis is than the length of the periodic scale elements along each measuring axis. The offset of the periodically-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

6873422, Mar 29, 2005

Dec 8, 2000

09/731671

Michael Nahum - Kirkland WA, US
Patrick H. Mawet - Snohomish WA, US

Mitutoyo Corporation - Kawasaki

G06K009/64

356614, 382278, 382295

An image comparison method and an interpolation method to determine the image offset corresponding to the extreme value of the comparison contributes to systematic errors in estimating the displacement of the surface from the images. The systematic errors are rejected by correlation-based comparison systems and methods which reduce the curvature of the correlation function for offsets that bound the extreme value, and by interpolation systems and methods that are relatively insensitive to the asymmetry of the correlation function value points selected as the basis for the interpolation. These systems and methods allow fast, highly accurate, displacement determinations using relatively simplified calculations and relatively few correlation function value points.