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US 2001/0022648 A1Published application
Optical tracking based on a change in optical reflection across a reference mark on an object to be tracked
OwnerMing Laiinventor
Life of this patent
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Abstract
An optical tracking device and method are disclosed for tracking lateral movement of an object. A scanning probe beam and a time-resolved detection are implement in the disclosed technique. A particular application is for tracking the eye movement during a laser surgery.
Claims20
A method for optically tracking movement of an object, comprising:
- selecting a reference mark on an object where first and second surface areas on opposite sides of the reference mark on the object are different in an optical property;
- repetitively scanning an optical probe beam from the first surface area to the second surface area across the reference mark at a selected scanning speed along a selected direction so that a property of a scattered probe beam that is scattered from the object changes due to the change in the optical property in the first and second surface areas when the probe beam passes through the reference mark;
- detecting a time at which the change in the property of the scattered probe beam occurs when the probe beam scans across the reference mark;
- determining a time difference between the time and a reference time;
- and
- using the time difference to determine an amount of movement of the object along the selected direction.
3 more elements
An optical device, comprising:
- a probe scanner to scan an optical probe beam across a reference mark on an object where first and second surface areas on opposite sides of the reference mark on the object are different in an optical property, said probe scanner operable to repetitively scan the optical probe beam from the first surface area to the second surface area across the reference mark at a selected scanning speed along a selected direction;
- and
- a probe detection unit positioned to receive a scattered probe beam that is scattered from the object and to detect a change in a property of the scattered probe beam due to the change in the optical property in the first and second surface areas when the probe beam passes through the reference mark,
- wherein said probe detection unit is operable to detect a time at which the change in the property of the scattered probe beam occurs and an amount of movement of the object along the selected direction according to a time difference between the time and a reference time.
1 more element
Dependencies are inferred from the claim text.