Three dimensional position measurement system using an interferometer

Claim 2

An improved interferometer of the type in which beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflector section is translated freely in three dimensions; means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; and means for measuring the direction of the test beam.

Claim 3

An interferometer as in claim 1 wherein said means for controlling the first direction comprises: a first detector, within the reflecting section, that is responsive to a beam of light emitted from the generating section in the first direction; and first beam directing means within the generating section and responsive to the first detector for controlling the first direction.

Claim 4

An interferometer as in claim 2 wherein said beam generating section further comprises an auxiliary source of collimated light that produces the beam to which said first detector is responsive.

Claim 5

An interferometer as in claim 2 wherein said reflecting section further comprises a first reflector on which the test beam is to be directed and wherein the first detector is rigidly attached to the first reflector.

Claim 6

An interferometer as in claim 4 wherein the first reflector is a cube corner having an apex at which the first detector is attached.

Claim 7

An improved interferometer of the type is which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; said means for controlling the first direction comprising: a first detector, within the reflecting section, that is responsive to a beam of light emitted from the generating section in the first direction; and first beam directing means within the generating section and responsive to the first detector for controlling the first direction; wherein the beam directing means comprises a first gimbal having at least two rotation axes, said beam directing means being mounted on said first gimbal.

Claim 8

An improved interferometer of the type is which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; said means for controlling the first direction comprising: a first detector, within the reflecting section, that is responsive to a beam of light emitted from the generating section in the first direction; and first beam directing means within the generating section and responsive to the first detector for controlling the first direction; wherein the beam directing means comprises a first gimbal having at least two rotation axes, said beam directing means being mounted on said first gimbal.

Claim 9

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; said means for controlling the first direction comprising: a first detector, within the reflecting section, that is responsive to a beam of light emitted from the generating section in the first direction; and first beam directing means within the generating section and responsive to the first detector for controlling the first direction; wherein the beam directing means comprises a first gimbal having at least two rotation axes, said beam directing means being mounted on said first gimbal.

Claim 10

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; said means for controlling the first direction comprising: a first detector, within the reflecting section, that is responsive to a beam of light emitted from the generating section in the first direction; and first beam directing means within the generating section and responsive to the first detector for controlling the first direction; wherein the beam directing means comprises a first gimbal having at least two rotation axes, said beam directing means being mounted on said first gimbal.

Claim 11

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; wherein said reflecting section returns the test beam along a second direction to the generating section and wherein said means for controlling the generating section comprises: a second detector, within the generating section, that is responsive to a beam of light emitted from the reflecting section in the second direction; and second beam directing means within the reflecting section and responsive to the second detector for controlling the second direction.

Claim 12

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; wherein said reflecting section returns the test beam along a second direction to the generating section and wherein said means for controlling the generating section comprises: a second detector, within the generating section, that is responsive to a beam of light emitted from the reflecting section in the second direction; and second beam directing means within the reflecting section and responsive to the second detector for controlling the second direction.

Claim 13

An interferometer as in claim 8 wherein said beam generating section further comprises an auxiliary source of collimated light that produces the beam to which said second detector is responsive; and wherein said reflecting section further comprises a second reflector that reflects the beam from the auxiliary source into the second direction.

Claim 14

An interferometer as in claim 8 wherein the second beam directing means comprises a second gimbal having at least two rotation axis, and a second beam deflector mounted on said second gimbal.

Claim 15

An interferometer as in claim 8 wherein the second beam directing means comprises a second gimbal having at least two rotation axes, said beam reflecting section being mounted on said second gimbal.

Claim 16

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; means for measuring a pair of directional angles that determine the first direction.

Claim 17

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first direction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; means for measuring a pair of directional angles that determine the first direction.

Claim 18

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first dirction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; means for moving the reflecting section between a pair of points Q1 and Q2 equidistant from the generating section; means for measuring the distance between points Q1 and Q2; and means for measuring the angle subtended at the generating section between point Q1 and Q2.

Claim 19

An improved interferometer of the type in which a beam generating section having a first source of coherent collimated light produces a first beam of light that is divided at a first beam splitter into a reference beam that is directed along a reference path and a test beam that is directed in a variable first dirction to a movable reflecting section, said movable reflecting section directing the test beam back to a point F at which the reference and test beams are recombined to produce an interfering output beam, said improvement comprising: means for controlling the first direction so that the test beam is incident on the movable reflecting section even when the movable reflecting section is translated freely in three dimensions; and means for controlling the movable reflecting section so that said test beam is directed back to point F even when the movable reflecting section is translated freely in three dimensions; means for moving the reflecting section between a pair of points Q1 and Q2 equidistant from the generating section; means for measuring the distance between points Q1 and Q2; and means for measuring the angle subtended at the generating section between point Q1 and Q2.