Orientation independent focus mechanisms for laser radar
AssigneesNikon Corporation, Lorri L. Watson
InventorsAlec Robertson, Douglas C. Watson, Alexander Cooper
Life of this patent
Estimating the term…
Abstract
Focus arrangements for laser radar and other applications provide compensation of orientation-dependent gravitational forces. A linear stage can be preloaded and provided with balanced linear encoders so that gravitational force induced pitch, yaw, and roll can be reduced, detected, or compensated. Alternatively, movable focus elements can be secured to actuator driven spring assemblies that are controlled to compensate orientation-dependent gravitational forces.
Claims24
A focus stage, comprising:
- a linear stage that includes a carriage and a guide;
- a motor configured to translate the carriage along an axis defined by the guide;
- and
- first and second linear encoders oppositely situated along the axis and configured to provide an indication of carriage position based on combination of encoder signals from the first and second linear encoders.
An actuator system, comprising:
- a first actuator configured to be secured to an optical system and scan the optical system along an axis from an initial position;
- a second actuator;
- and
- an elastic member coupled to the second actuator, wherein the second actuator is configured to apply a force with the elastic member to compensate an orientation-dependent gravitational force on the optical system.
An apparatus, comprising:
- an optical element secured to a first actuator;
- an elastic member secured to a second actuator, wherein at least one of the optical element and the first actuator are coupled to the elastic member, and at least one of the first actuator and the second actuator are configured so that a force on the optical element associated with the elastic member corresponds to an orientation-dependent gravitational force.
A focus system, comprising:
- a linear stage that includes a carriage and a guide;
- a motor configured to translate the carriage along an axis defined by the guide;
- first and second linear encoders oppositely situated along the axis and configured to provide an indication of carriage position based on combination of encoder signals from the first and second linear encoders;
- a focus adjustment optical element;
- and
- an actuator and an elastic member coupled to the focus adjustment optical element so as to compensate orientation-dependent forces.
A measurement device, comprising
- a linear stage that includes a carriage and a guide;
- a motor configured to translate the carriage along an axis defined by the guide;
- first and second linear encoders oppositely situated along the axis and configured to provide an indication of carriage position based on a combination of encoder signals from the first and second linear encoders;
- a focus adjustment optical element configured to produce a measurement beam from a light source and to receive a return beam from a target;
- and
- a signal processor configured to provide an estimated target distance for at least one target location based on the return beam
Dependencies are inferred from the claim text.