Spatial modulation of light to determine dimensional characteristics of objects in a flow path

US9207066B2 · kind B2 · utility

Assignee

• Palo Alto Research Center Incorporated · US

Inventors

• Joerg Martini · San Francisco, US
• Marshall W. Bern · Redwood City, US
• Noble M. Johnson · Menlo Park, US
• Peter Kiesel · Palo Alto, US
• Doron Kletter · San Mateo, US
• Bowen Cheng · Atherton, US
• Michael I. Recht · Redwood City, US

Key dates

• Filing date: Feb 14, 2014
• Grant date: Dec 8, 2015
• Expiry date: Feb 20, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B11/0691
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device includes a spatial filter arranged in a Cartesian coordinate system having orthogonal x, y, and z axes. The spatial filter has mask features that are more light transmissive and mask features that are less light transmissive. The mask features are arranged along the x-axis in the flow direction of a flow path. A detector is positioned to detect light emanating from at least one object in the flow path, the object having a width along the y-axis, a thickness along the z-axis, and a length along the x-axis. Light emanating from the object is time modulated according to the mask features as the object moves along the flow path. The detector is configured to generate a time-varying electrical signal in response to the detected light that includes information about the width or thickness of the object.