SPATIAL MODULATION OF LIGHT TO DETERMINE DIMENSIONAL CHARACTERISTICS OF OBJECTS IN A FLOW PATH

摘要

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.

主权项

1. An assembly, comprising:
a spatial filter arranged in a Cartesian coordinate system having orthogonal x, y, and z axes, the spatial filter including mask features that are more light transmissive and mask features that are less light transmissive, the mask features arranged along the and x-axis in a flow direction of a flow path; a detector 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, the light emanating from the object time modulated according to the mask features as the object moves along the flow path, the detector configured to generate a time-varying electrical signal in response to the detected light; and an analyzer configured to determine the width or thickness of the object based on the signal.