Device for determining guidance errors

Claim 2

In combination, a relatively fixed body and a movable body having guided coaction with said fixed body for displacement between spaced points on said fixed body and along a given axis with respect thereto, optical means on said fixed body establishing between said spaced points an optical-axis reference for the precise alignment of said given axis, first discriminator means including a first afocal optical system operative on said optical-axis reference and Carried by said movable body for sensing lateral error deviation of said element with respect to said axis, and second discriminator means including a second afocal optical system operative on said optical-axis reference and carried by said movable body for sensing directional tilting error deviation of said second element with respect to said axis, said afocal optical systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 3

The combination of claim 1, wherein said first and second elements are on spaced parallel optical-reference axes, each of which is parallel to said given axis and is established between spaced points on said fixed body.

Claim 4

The combination of claim 2, in which a characteristic mark system is located at each of the fixed points for each of said parallel optical-reference axes, the afocal systems carried by said movable body being aligned unique to a different one of said axes, whereby the mark systems at the fixed-body reference points of each axis are imaged upon one another.

Claim 5

The combination of claim 3, in which the mark system at one fixed-body reference end of one of said axes includes means responsive to deviation between a locally inscribed mark and the corresponding projected mark for deriving an electrical error-signal output.

Claim 6

The combination of claim 1, in which said optical-axis reference comprises three parallel fixed-body axes established in a given plane, and in which two afocal imaging systems of imaging characteristic Beta '' -1 are disposed in equally spaced relation on opposite sides of a third afocal imaging system of imaging characteristic Beta '' +1.

Claim 7

The combination of claim 1, in which the afocal imaging system with the imaging characteristic Beta '' +1 contains an image-erecting prism.

Claim 8

The combination of claim 3, in which the mark systems consist of graticules with lines extending in perpendicular relation in planes normal to the said optical-reference axes.

Claim 9

The combination of claim 7, in which for at least one of said axes the mark system at one fixed-body end is characterized by single-line markings and the mark system at the other fixed-body end is characterized by double-line markings.

Claim 10

The combination of claim 7, in which for at least one of said axes the mark system at one fixed-body end is characterized by scale graduations and the mark system at the other fixed-body end is characterized by an index mark.

Claim 11

The combination of claim 7, in which for at least one of said axes the mark system at one fixed-body end is characterized by raster markings.

Claim 12

The combination of claim 4, and including corrective drive means responsive to said electrical error-signal output and connected to impart a repositioning displacement component to said movable body in the sense opposed to the direction of the detected error component, whereby said drive means is operative to reduce the detected error-signal output to zero.

Claim 13

In combination, a relatively fixed body and a movable body having guided coaction for displacement of said movable body between spaced longitudinal parts of said fixed body and along a given axis with respect thereto; first discriminator means including means on said spaced parts of said fixed body establishing a first fixed optical axis parallel to said given axis, and a first afocal optical system carried by said moving body and substantially centered on said first fixed optical axis; second discriminator means including means on said spaced parts of said fixed body establishing a second fixed optical axis parallel to said given axis, and a second afocal optical system carried by said moving body and substantially centered on said second fixed optical axis; said afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 14

In combination, a relatively fixed body and a movable body having guided coaction for displacement of said movable body between spaced longitudinal parts of said fixed body and along a given axis with respect thereto; first discriminator means including means on said spaced parts of said fixed body establishing a first fixed optical axis parallel to said given axis, and a first afocal optical system carried by said moving body and substantially centered on said first fixed optical axis; second discriminator means including means on said spaced parts of said fixed body establishing a second fixed optical axis parallel to said given axis, and a second afocal optical system carried by said moving body and substantially centered on said second fixed optical axis; said afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 15

The combination of claim 12, in which said movable body is a main Slide, and in which a cross slide has guided coaction with said main slide for displacement between transversely spaced parts of said main slide and in a transverse axial component of direction; third discriminator means including means on said transversely spaced parts of said main slide establishing a first transverse optical axis parallel to said axial component of direction, and a third afocal optical system carried by said cross slide and substantially centered on said first transverse optical axis; fourth discriminator means including means on said transversely spaced parts of said main slide establishing a second transverse optical axis parallel to said axial component of direction, and a fourth afocal optical system carried by said cross slide and substantially centered on said second transverse optical axis; said last two afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 16

In combination, a relatively fixed body and a movable body having guided coaction for two-coordinate displacement of said movable body between first spaced parts of said fixed body in a first-coordinate direction with respect thereto, said guided displacement being also between second spaced parts of said fixed body in a second-coordinate direction orthogonal to said first-coordinate direction; first discriminator means including means on said first-spaced parts of said fixed body establishing a first fixed optical-axis reference parallel to said first-coordinate direction, and a first afocal optical system carried by said moving body and substantially on said first fixed optical-axis reference; second discriminator means including means on said first spaced parts of said fixed body establishing a second fixed optical-axis reference parallel to said first-coordinate direction, and a second afocal optical system carried by said moving body and substantially on said second fixed optical-axis reference; third discriminator means including means on said second spaced parts of said fixed body establishing a third fixed optical-axis reference parallel to said second-coordinate direction, and a third afocal optical system carried by said moving body and substantially on said third fixed optical-axis reference; said first and second afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 17

In combination, a relatively fixed body and a movable body having guided coaction for two-coordinate displacement of said movable body between first spaced parts of said fixed body in a first-coordinate direction with respect thereto, said guided displacement being also between second spaced parts of said fixed body in a second-coordinate direction orthogonal to said first-coordinate direction; first discriminator means including means on said first-spaced parts of said fixed body establishing a first fixed optical-axis reference parallel to said first-coordinate direction, and a first afocal optical system carried by said moving body and substantially on said first fixed optical-axis reference; second discriminator means including means on said first spaced parts of said fixed body establishing a second fixed optical-axis reference parallel to said first-coordinate direction, and a second afocal optical system carried by said moving body and substantially on said second fixed optical-axis reference; third discriminator means including means on said second spaced parts of said fixed body establishing a third fixed optical-axis reference parallel to said second-coordinate direction, and a third afocal optical system carried by said moving body and substantially on said third fixed optical-axis reference; said first and second afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 18

The combination of claim 14, in which said third afocal system has the imaging characteristic Beta '' -1.

Claim 19

The combination of claim 14, additionally including fourth discriminator means including means on said second spaced parts of said fixed body establishing a fourth fixed optical-axis reference parallel to said second-coordinate direction, and a fourth afocal optical system carried by said moving body and substantially on said fourth fixed optical-axis reference; said third and fourth afocal systems having imaging characteristics Beta '' +1 and Beta '' -1, respectively.

Claim 20

The combination of claim 14, in which each of the first spaced parts serving said first and second optical-axis references includes a scale with equally spaced like graduations.

Claim 21

The combination of claim 17, in which the scale graduations additionally include elongate lines parallel to the plane of two-coordinate movement.