US 2026/0298626 A1 · APPARATUS AND METHOD FOR DETECTION OF DISTANCE SENSOR BEAM MISALIGNMENT

Abstract

An apparatus and method for detecting beam misalignment in a thickness measurement system employing two opposed distance measurement sensors. The apparatus includes a first and second distance measurement sensor configured to direct respective light beams toward opposite sides of a measurement space, and a rotatable support member disposed between the sensors for receiving and rotating a sample about a rotation axis. The sample has at least one surface inclined at a tilt angle relative to a propagation direction of a corresponding light beam. A controller obtains thickness measurements from the sensors at a plurality of rotational positions of the rotatable support member and detects a presence of beam misalignment between the first and second light beams based on a variation in the thickness measurements across the plurality of rotational positions. The method involves positioning the tilted sample between the opposed sensors, directing the light beams toward the sample surfaces, rotating the sample while obtaining thickness measurements, and analyzing the variation in those measurements to detect beam misalignment.

Claims20

Dependent claims

A method for detecting misalignment between light beams of two opposed distance measurement sensors in a thickness measurement system, the method comprising:

positioning a sample between the two opposed distance measurement sensors such that the sample is within a working range of each of the sensors, the sample having a first surface facing a first one of the sensors and a second surface facing a second one of the sensors, at least one of the first and second surfaces being inclined at a tilt angle relative to a beam propagation direction of a corresponding one of the light beams;
directing the light beams from the two opposed distance measurement sensors toward the first and second surfaces, respectively, of the sample to obtain thickness measurements of the sample;
rotating the sample about a rotation axis while obtaining the thickness measurements at a plurality of rotational positions of the sample;
and
analyzing a variation in the thickness measurements across the plurality of rotational positions to detect a presence of beam misalignment between the light beams of the two sensors.

2 more elements

An apparatus for detecting beam misalignment in a thickness measurement system, the apparatus comprising:

a first distance measurement sensor configured to direct a first light beam toward a first side of a measurement space;
a second distance measurement sensor opposed to the first distance measurement sensor and configured to direct a second light beam toward a second side of the measurement space opposite the first side;
a rotatable support member disposed in the measurement space between the first and second distance measurement sensors and configured to receive and rotate a sample about a rotation axis, such that when a sample having at least one surface inclined at a tilt angle relative to a propagation direction of a corresponding one of the first and second light beams is supported by the rotatable support member, the sample is within a working range of each of the first and second distance measurement sensors;
and
a controller operatively coupled to the first and second distance measurement sensors and configured to:
obtain thickness measurements from the first and second distance measurement sensors at a plurality of rotational positions of the rotatable support member, and
detect a presence of beam misalignment between the first and second light beams based on a variation in the thickness measurements across the plurality of rotational positions.

4 more elements

A system for automatically correcting beam misalignment in a thickness measurement system, the system comprising:

a first distance measurement sensor and a second distance measurement sensor arranged in opposition and defining a measurement space therebetween;
a rotatable support member disposed in the measurement space and configured to receive and rotate a calibration sample about a rotation axis, the rotatable support member being positioned such that a calibration sample supported thereon is within a working range of each of the first and second distance measurement sensors;
an alignment actuator coupled to at least one of the first and second distance measurement sensors and configured to adjust a position of the at least one sensor;
and
a controller operatively coupled to the first and second distance measurement sensors, the rotatable support member, and the alignment actuator, the controller configured to:
obtain thickness measurements at a plurality of rotational positions of the rotatable support member,
detect beam misalignment between light beams of the first and second distance measurement sensors based on a variation in the thickness measurements,
determine at least one of a magnitude and a direction of the beam misalignment, and
cause the alignment actuator to adjust the position of the at least one sensor to reduce the beam misalignment.

6 more elements

Dependencies are inferred from the claim text.

Apparatus and method for detection of distance sensor beam misalignment

Life of this patent

Apparatus and method for detection of distance sensor beam misalignment

Life of this patent

Abstract

Claims20