Diffractographic measurement of profile

Claim 3

A method according to claim 1 wherein said directed electromagnetic radiation is passed through a cylinder lens.

Claim 4

A method according to claim 1 wherein said electromagnetic raDiation is focussed to a line on at least one of said reference diffraction wave producing means and said object boundary diffraction wave producing means.

Claim 5

A method according to claim 1 wherein said first and second interference patterns are formed simultaneously.

Claim 6

A method according to claim 4 wherein said electromagnetic radiation is passed through a cylinder lens positioned to direct said electromagnetic radiation simultaneously onto said first and second discrete portions of said object boundary diffraction wave producing means.

Claim 7

A method according to claim 1 wherein said reference diffraction wave producing means comprises a non-linear boundary of an object.

Claim 8

A method according to claim 1 wherein a beam of electromagnetic radiation is moved along said object boundary to sequentially direct electromagnetic radiation of said beam at said first and second discrete portions of said object boundary diffraction wave producing means.

Claim 9

A method according to claim 1 wherein said step of comparing said first and second, single, interference patterns comprises determining the spatial position of a portion of said first, single, interference pattern, and comparing that spatial position with the spatial position of a portion of said second, single, interference pattern.

Claim 10

A method according to claim 1 wherein said electromagnetic radiation comprises electromagnetic radiation of at least two discrete wave lengths.

Claim 11

A method according to claim 1 including the further step of forming said first and second interference patterns on a member upon which are provided corresponding interference patterns produced on said member at a time when said reference diffraction wave producing means was separated a known distance from said object boundary diffraction wave producing means.

Claim 12

Apparatus for determining the profile of an object boundary comprising: an elongate reference diffraction wave producing means having a known spatial configuration; elongate object boundary diffraction wave producing means spaced from said elongate reference diffraction wave producing means such that an elongate gap is provided therebetween; means for directing electromagnetic radiation at said reference diffraction wave producing means at a first discrete portion of said object boundary diffraction wave producing means and at a first discrete portion of said reference diffraction wave producing means to form a first, single, interference pattern caused by interaction of waves diffracted from said reference diffraction wave producing means and said object boundary diffraction wave producing means; means for directing electromagnetic radiation at said reference diffraction wave producing means at a second discrete portion of said object boundary diffraction wave producing means and at a second discrete portion of said reference diffraction wave producing means, said second discrete portions being spaced longitudinally from said first discrete portions along the elongate object boundary diffraction wave producing means and reference diffraction wave producing means, respectively, to form a second, single, interference pattern caused by interaction of waves diffracted from said reference diffraction wave producing means and said object diffraction wave producing means; and means for determining from said first and second, single, interference patterns the profile of said object boundary.

Claim 13

Apparatus for determining the profile of an object boundary comprising: an elongate reference diffraction wave producing means having a known spatial configuration; elongate object boundary diffraction wave producing means spaced from said elongate reference diffraction wave producing means such that an elongate gap is provided therebetween; means for directing electromagnetic radiation at said reference diffraction wave producing means at a first discrete portion of said object boundary diffraction wave producing means and at a first discrete portion of said reference diffraction wave producing means to form a first, single, interference pattern caused by interaction of waves diffracted from said reference diffraction wave producing means and said object boundary diffraction wave producing means; means for directing electromagnetic radiation at said reference diffraction wave producing means at a second discrete portion of said object boundary diffraction wave producing means and at a second discrete portion of said reference diffraction wave producing means, said second discrete portions being spaced longitudinally from said first discrete portions along the elongate object boundary diffraction wave producing means and reference diffraction wave producing means, respectively, to form a second, single, interference pattern caused by interaction of waves diffracted from said reference diffraction wave producing means and said object diffraction wave producing means; and means for determining from said first and second, single, interference patterns the profile of said object boundary.

Claim 14

Apparatus according to claim 11 including cylinder lens means for directing electromagnetic radiation at said reference diffraction wave producing means and said object boundary diffraction wave producing means.

Claim 15

Apparatus according to claim 11 including means for focussing said electromagnetic radiation to a line on at least one of said reference diffraction wave pattern means and said object boundary diffraction wave producing means.

Claim 16

Apparatus according to claim 11 wherein said first and second interference patterns are formed simultanEously.

Claim 17

Apparatus according to claim 11 wherein said reference diffraction wave producing means comprises a non-linear boundary of an object.

Claim 18

Apparatus according to claim 11 further including means for forming a beam of electromagnetic radiation and means to move said beam of electromagnetic radiation to sequentially direct electromagnetic radiation of said beam at said first and second discrete portions of said object diffraction wave producing means.

Claim 19

Apparatus according to claim 11 further including means for determining the spatial position of a portion of said first, single, interference pattern and means for determining the spatial position of a portion of said second, single, interference pattern.

Claim 20

Apparatus according to claim 1 further including means for enlarging an interference pattern caused by interaction of waves diffracted from said reference diffraction wave producing means and said object diffraction wave producing means.

Claim 21

Apparatus according to claim 1 wherein said electromagnetic radiation directing means comprises means for producing electromagnetic radiation of at least two discrete wavelengths.

Claim 22

Apparatus according to claim 11 including means for fixing the position of said reference diffraction wave producing means relative to said electromagnetic radiation directing means.

Claim 23

A method according to claim 1 wherein said reference diffraction wave producing means is fixed relative to the interference patterns produced.

Claim 24

Apparatus according to claim 11 including means for comparing said first and second interference patterns and means for fixing the position of said reference diffraction wave producing means relative to said interference pattern comparing means.

Claim 25

Apparatus according to claim 11 including means for detecting said interference pattern, said detecting means being displaced from said gap a distance much greater than the distance across said gap.

Claim 26

A method according to claim 1 wherein said first and second interference patterns are displayed on a member fixed in space relative to said reference diffraction wave producing means.

Claim 27

Apparatus according to claim 11 including means for displaying said first and second diffraction patterns on a member fixed in space relative to said reference diffraction wave producing means.

Claim 28

A method according to claim 1 wherein said interference patterns are recorded on a photosensitive member.

Claim 29

Apparatus according to claim 11 wherein said reference diffraction wave producing means and object boundary diffraction wave producing means are spaced a distance in the direction of propogation of said electromagnetic radiation.

Claim 30

A method according to claim 1 wherein said object boundary diffraction wave producing means is located on a surface moving in the direction of propogation of said electromagnetic radiation.

Claim 31

Apparatus according to claim 11 wherein said object boundary diffraction wave producing means comprises the surface of a member moveable in the direction of propogation of said electromagnetic radiation and including means for moving said member in said direction.

Claim 32

A method according to claim 1 wherein said object boundary diffraction wave producing means is moveable in a direction substantially perpendicular to said elongate gap.

Claim 33

Apparatus according to claim 27 including means for moving said object boundary diffraction wave producing means in a direction substantially perpendicular to said elongate gap.

Claim 34

Apparatus according to claim 11 wherein said reference diffraction wave producing means comprises a member having two elongate object boundaries.

Claim 35

Apparatus according to claim 32 wherein said reference diffraction wave producing means comprises a wire or slit.

Claim 36

Apparatus according to claim 11 including photoelectric means for detecting said interference patterns.

Claim 37

Apparatus according to claim 34 wherein said photoelectric means comprises photoelectric detector means located at a fixEd angular position with respect to the axis of symmetry of said interference patterns.

Claim 38

Apparatus according to claim 35 wherein said detector means comprises two adjacent detectors disposed colinearly with said interference pattern and centered about the location of said detector means.

Claim 39

Apparatus according to claim 34 wherein said photoelectric means comprises a television camera.

Claim 40

Apparatus according to claim 34 wherein said photoelectric means comprises a line scan photodiode array.