Nicholas L Allen

US Patent:

53897943, Feb 14, 1995

Filed:

Nov 25, 1992

Appl. No.:

7/981745

Inventors:

Nicholas C. Allen - Bedford MA
Sergey V. Broude - Newton Centre MA
Eric T. Chase - Nashua NH
Pascal Miller - North Chelmsford MA
Jay L. Ormsby - Salem NH
Bruno Rostaing - Medford MA
Lloyd P. Quackenbos - Newburyport MA

Assignee:

QC Optics, Inc. - Burlington MA

International Classification:

G01N 2188

US Classification:

250572

Abstract:

A surface pit and mound detection and discrimination system including a device for scanning a beam of radiation over a surface, and a mechanism for detecting a local slope on the surface for differentiating between whether the beam of radiation is scanning a pit or a mound on the surface.

US Patent:

56728859, Sep 30, 1997

Filed:

Jul 10, 1995

Appl. No.:

8/499822

Inventors:

Nicholas Allen - Bedford MA
Sergey Broude - Newton Centre MA
Eric Chase - Carlisle MA
Carl Johnson - Tewksbury MA
Pascal Miller - North Chelmsford MA
Jay Ormsby - Salem MA
Arkady Savikovsky - Brookline MA

Assignee:

QC Optics, Inc. - Burlington MA

International Classification:

G01N 2189

US Classification:

2505593

Abstract:

A surface displacement detection system including a detector for detecting displacement of a surface in a direction normal to the surface as the surface revolves; an encoder which divides the surface into N sectors; a signal processor responsive to the detector for calculating the amount of displacement of the surface in each sector of the surface as it revolves; a displacement value look-up table; and a routine for writing to the table a displacement value for each sector once per M revolutions, and an adjustment system including a focussing actuating element, a routine to read displacement value look-up table, a routine to for updating the position of the focussing actuating element for every sector, according to the displacement values stored in the look-up table.

US Patent:

56107196, Mar 11, 1997

Filed:

Jul 10, 1995

Appl. No.:

8/500433

Inventors:

Nicholas Allen - Bedford MA
Sergey Broude - Newton Centre MA
Eric Chase - Carlisle MA
Carl Johnson - Tewksbury MA
Pascal Miller - North Chelmsford MA
Jay Ormsby - Salem MA
Arkady Savikovsky - Brookline MA

Assignee:

QC Optics, Inc. - Burlington MA

International Classification:

G01B 1100

US Classification:

356374

Abstract:

A system for detecting displacement of a surface in a direction normal to the surface, the system including a first grating; a second grating; an optical subsystem for projecting an image of the first grating onto the surface and for directing a secondary image of the first grating reflected off the surface onto the second grating; and a detector, responsive to the fringe pattern formed after the secondary image passes through the second grating, for detecting displacement of the surface in a direction normal to the surface.