Diffractographic and other sensors utilizing diffraction waves

Claim 3

A method according to claim 1 wherein said means for producing said first diffraction wave comprises a boundary.

Claim 4

A method according to claim 1 wherein said means for producing said first diffraction wave comprises a first member having two boundaries, and said means for producing said second diffraction wave comprises a second member having two boundaries.

Claim 5

A method according to claim 1 wherein said first and second means for producing said first and second diffraction waves each comprise a diffraction grating.

Claim 6

A method according to claim 1 wherein said means for producing said first diffraction wave comprises a boundary of said first member, said first member being moveable relative to said secOnd member such that the portion of said boundary upon which said electromagnetic radiation is directed is changed, said method including the further step of moving said boundary to change said portion of said boundary, and detecting changes in the intensity of an interference pattern produced by one portion of said boundary with an interference pattern produced by another portion of said boundary.

Claim 7

A method according to claim 1 wherein said means for producing said first diffraction wave and said means for producing said second diffraction wave are spaced a distance in the direction of said axis of said interference pattern.

Claim 8

A method according to claim 6 including the further step of detecting the intensity of electromagnetic radiation at an additional detection means a fixed distance from said axis of said interference pattern.

Claim 9

A method according to claim 7 wherein said distance in the direction of said axis of said interference pattern is selected such that the interference pattern fringe portion detected at the first mentioned detection means is not the same as the interference pattern fringe portion detected at said additional detection means.

Claim 10

A method according to claim 7 including the further step of counting the number of fringes moving relative to said second detection means.

Claim 11

A method according to claim 1 wherein said first member includes means for producing a third diffraction wave and said second member includes means for producing a fourth diffraction wave, said fourth diffraction wave producing means being separated from said third diffraction wave producing means, said separation being different from the separation of said first and second diffraction wave producing means, and wherein the process includes the further steps of: directing electromagnetic waves onto said third and fourth diffraction wave producing means to produce a further interference pattern including fringes positioned about an axis in the direction of propogation of said electromagnetic radiation, said further interference pattern being produced by interaction between said third and fourth diffraction waves; and detecting changes in intensity of electromagnetic radiation with further detection means located at a fixed distance from said axis of said further interference pattern to detect motion of said fringes of said further interference pattern relative to said further detection means.

Claim 12

A method according to claim 1 wherein said step of detecting changes in intensity at said detection means includes detecting and counting the whole number of fringes and detecting and determining any fraction of a fringe of said interference pattern moving past said detection means.

Claim 13

A method according to claim 11 wherein said change in separation of said first and second members represents an event, said counting of fringes being accumulated over a plurality of events.

Claim 14

A method according to claim 11 including the step of determining the magnitude of any partial fringe moving past said detection means by changing the wavelength of said electromagnetic radiation a known amount such that a maximum or minimum is detected by said detection means.

Claim 15

A method according to claim 11 including the step of determining the magnitude of any partial fringe moving past said detection means by changing the separation of said first and second members a known amount such that a maximum or minimum is detected by said detection means.

Claim 16

A method according to claim 11 including the step of determining the magnitude of any partial fringe moving past said detection means by changing the position of said detection means a known amount such that a maximum or minimum is detected by said detection means.

Claim 17

A method according to claim 11 wherein a first source of electromagnetic radiation is used to direct waves onto said first diffraction wave producing means and a second source of electromagnetic radiation is used to direct waves onto said second diffrAction wave producing means and including the step of determining the magnitude of any partial fringe moving past said detection means by changing the relative phase of the electromagnetic radiation incident upon said first and second diffraction wave producing means by a known amount such that a maximum or minimum is detected by said detection means.

Claim 18

A method according to claim 1 wherein said electromagnetic waves are passed through a cylinder lens.

Claim 19

A method according to claim 1 wherein said detection means comprises two adjacent detectors spaced in the direction of fringe spacing of said interference pattern and centered about the location of said detection means.

Claim 20

A method according to claim 1 wherein said first diffraction wave producing means comprises a member in contact with an object for determining motion of the object.

Claim 21

A method according to claim 1 wherein the step of determining said changes in separation comprises the step of counting the number of fringes moving past said detection means.

Claim 22

A method according to claim 1 wherein said electromagnetic radiation is directed onto said first and second diffraction wave producing means stroboscopically.

Claim 23

Apparatus for determining a change in the separation of first and second members, said first member including means for producing a first diffraction wave, said second member including means for producing a second diffraction wave, said second diffraction wave producing means being separated from said first diffraction wave producing means, said first and second diffraction wave producing means each comprising a single boundary or a plurality of single boundaries spaced in a direction transverse to the direction of electomagnetic waves directed thereonto, each of said single boundaries being capable of producing a single diffraction wave upon incidence thereon of said electromagnetic waves, said apparatus comprising: means for directing electromagnetic waves onto said first and second diffraction wave producing means to produce an interference pattern including fringes positioned about an axis in the direction of propogation of said electromagnetic waves, said interference pattern being produced by interaction between said first and second waves; means for detecting the intensity of electromagnetic radiation located at a fixed distance from said axis of said interference pattern for detecting changes in intensity of said electromagnetic radiation to detect a portion said fringes of said interference pattern as they move past said detection means; and means for determining from said detected changes in electromagnetic radiation a change in separation between said first and second diffraction wave producing means.

Claim 24

Apparatus for determining a change in the separation of first and second members, said first member including means for producing a first diffraction wave, said second member including means for producing a second diffraction wave, said second diffraction wave producing means being separated from said first diffraction wave producing means, said first and second diffraction wave producing means each comprising a single boundary or a plurality of single boundaries spaced in a direction transverse to the direction of electomagnetic waves directed thereonto, each of said single boundaries being capable of producing a single diffraction wave upon incidence thereon of said electromagnetic waves, said apparatus comprising: means for directing electromagnetic waves onto said first and second diffraction wave producing means to produce an interference pattern including fringes positioned about an axis in the direction of propogation of said electromagnetic waves, said interference pattern being produced by interaction between said first and second waves; means for detecting the intensity of electromagnetic radiation located at a fixed distance from said axis of said interference pattern for detecting changes in intensity of said electromagnetic radiation to detect a portion said fringes of said interference pattern as they move past said detection means; and means for determining from said detected changes in electromagnetic radiation a change in separation between said first and second diffraction wave producing means.

Claim 25

Apparatus according to claim 22 wherein said means for producing said first diffraction wave comprises a boundary.

Claim 26

Apparatus according to claim 22 wherein said means for producing said first diffraction wave comprises a first member having two boundaries separated in a direction transverse to the direction of said electromagnetic radiation, and said means for producing said second diffraction wave comprises a second member having two boundaries separated in a direction transverse to the direction of said electromagnetic radiation, each of said boundaries being capable of producing a single diffraction wave upon incidence thereon of said electromagnetic radiation.

Claim 27

Apparatus according to claim 22 wherein said first and second means for producing said first and second diffraction waves each comprises a diffraction grating.

Claim 28

Apparatus according to claim 22 wherein said means for producing said first diffraction wave comprises a boundary of said first member, said apparatus further comprising means for moving said first member relative to said second member such that the portion of said boundary on which said electromagnetic radiation is directed is changed.

Claim 29

Apparatus according to claim 22 wherein said means for prodUcing said first diffraction wave and said means for producing said second diffraction wave are spaced a distance in the direction of said axis of said interference pattern.

Claim 30

Apparatus according to claim 27 including means for detecting the intensity of electromagnetic radiation at an additional location a fixed distance from said axis of said interference pattern.

Claim 31

Apparatus according to claim 28 wherein said distance in the direction of said axis of said interference pattern is selected such that the interference pattern fringe portion detected at the first mentioned detection means is not the same as the interference pattern fringe portion detected at said additional detection means.

Claim 32

Apparatus according to claim 28 including means for counting the number of fringes moving relative to said second detection means.

Claim 33

Apparatus according to claim 22 including cylinder lens means for passing said electromagnetic waves.

Claim 34

Apparatus according to claim 22 wherein said detection means comprises two adjacent detectors disposed colinearly with said interference pattern and centered about the location of said detection means.

Claim 35

Apparatus according to claim 22 wherein said detection means includes means for detecting and counting the whole number of fringes and means for detecting and determining any fraction of a fringe of said interference pattern moving past said detection means.

Claim 36

Apparatus according to claim 33 wherein said means for detecting any partial fringes moving past said detection means comprises means for changing the wavelength of said electromagnetic radiation a known amount such that a maximum or minimum is detected by said detection means.

Claim 37

Apparatus according to claim 33 wherein said means for detecting any partial fringes moving past said detection means comprises means for changing the separation of said first and second members a known amount such that a maximum or minimum is detected by said detection means.

Claim 38

Apparatus according to claim 33 wherein said means for detecting any partial fringes moving past said detection means comprises means for changing the position of said detection means a known amount such that a maximum or minimum is detected by said detection means.

Claim 39

Apparatus according to claim 33 including a first source of electromagnetic radiation for directing waves onto said first diffraction wave producing means and a second source of electromagnetic radiation for directing waves onto said second diffraction wave producing means and wherein said means for detecting any fraction of a fringe moving past said detection means comprises means for changing the relative phase of the electromagnetic radiation of said first and second sources by a known amount such that a maximum or minimum is detected by said detection means.

Claim 40

Apparatus according to claim 22 wherein said first member includes means for producing a third diffraction wave and said second member includes means for producing a fourth diffraction wave, said fourth diffraction wave producing means being separated from said third diffraction wave producing means, said separation being different from the separation of said first and second diffraction wave producing means, and wherein said apparatus further includes: means for directing further electromagnetic radiation onto said third and fourth diffraction wave producing means to produce a further interference pattern including fringes positioned about an axis in the direction of propogation of said further electromagnetic radiation, said further interference pattern being produced by interaction between said third and fourth diffraction waves; and means for detecting changes in intensity of electromagnetic radiation with further detection means located at a fixed distance from said axis of said further interference pattern to detect changes in intensity to detect motion of said fringes of said further interference pattern relative to said further detection meaNs.

Claim 41

Apparatus according to claim 22 wherein said first diffraction wave producing means comprises a member in contact with an object for determining motion of the object.

Claim 42

Apparatus according to claim 22 including means for directing said electromagnetic radiation onto said first and second diffraction wave producing means stroboscopically.

Claim 43

Apparatus according to claim 22 including means comprising a moveable member for masking the gap between said first and second diffraction wave producing means and means for moving said moveable member to unmask said gap, said moveable member having an edge forming a slit with one of said diffraction wave producing means as the gap is unmasked, the moving fringes of the interference pattern being formed as said gap is unmasked being countable to determine the magnitude of said gap width.

Claim 44

Apparatus according to claim 22 including means for changing the width of said detector relative to fringe spacing.

Claim 45

Apparatus according to claim 22 wherein said means for determining said changes in separation comprises means for counting the number of fringes moving past said detection means.

Claim 48

A method according to claim 44 wherein said interference patterns are recorded on a medium sensitive to said electromagnetic radiation and wherein the recordings are utilized to effect said comparison.

Claim 49

A method according to claim 44 wherein said maximum or minimum of the first-mentioned interference pattern is not the same as the maximum or minimum of said further interference pattern.

Claim 50

A method according to claim 44 wherein said means for producing said first diffraction wave comprises a boundary of said first member, said first member being moveable relative to said second member such that the portion of said boundary upon which said electromagnetic radiation is directed is changed, said method including the further step of moving said boundary to change said portion of said boundary, and detecting changes in the intensity of an interference pattern produced by one portion of said boundary with an interference pattern produced by another portion of said boundary.

Claim 51

A method according to claim 44 wherein said means for producing said first diffraction wave and said means for producing said second diffraction wave are spaced a distance in the direction of said axis of said interference pattern.

Claim 52

A method according to claim 44 wherein said first diffraction wave producing meanS comprises a member in contact with an object for determining motion of the object.

Claim 53

A method according to claim 44 wherein said electromagnetic radiation is directed onto said first and second diffraction wave producing means stroboscopically.

Claim 54

Apparatus for determining changes in the separation of first and second members, said first member including means for producing a first diffraction wave, said second member including means for producing a second diffraction wave, said second diffraction wave producing means being separated from said first diffraction wave producing means, said first and second diffraction wave producing means each comprising a single boundary or a plurality of single boundaries spaced in a direction transverse to the direction of electromagnetic waves directed thereonto, each of said single boundaries being capable of producing a single diffraction wave upon incidence thereon of said electromagnetic waves, said apparatus comprising: means for directing electromagnetic waves onto said first and second diffraction wave producing means to form an interference pattern, said interference pattern being produced by interaction between said first and second waves; means for determining the location of a single maximum or minimum of said interference pattern; means for comparing the locations of a single maximum or minimum of each of a plurality of said interference patterns; and means for determining from said comparison, the magnitude of any changes in separation of said first and second diffraction wave producing means.

Claim 55

Apparatus for determining changes in the separation of first and second members, said first member including means for producing a first diffraction wave, said second member including means for producing a second diffraction wave, said second diffraction wave producing means being separated from said first diffraction wave producing means, said first and second diffraction wave producing means each comprising a single boundary or a plurality of single boundaries spaced in a direction transverse to the direction of electromagnetic waves directed thereonto, each of said single boundaries being capable of producing a single diffraction wave upon incidence thereon of said electromagnetic waves, said apparatus comprising: means for directing electromagnetic waves onto said first and second diffraction wave producing means to form an interference pattern, said interference pattern being produced by interaction between said first and second waves; means for determining the location of a single maximum or minimum of said interference pattern; means for comparing the locations of a single maximum or minimum of each of a plurality of said interference patterns; and means for determining from said comparison, the magnitude of any changes in separation of said first and second diffraction wave producing means.

Claim 56

Apparatus according to claim 51 including means for recording said interference patterns on a medium sensitive to said electromagnetic radiation.

Claim 57

Apparatus according to claim 51 wherein said means for producing said first diffraction wave comprises a boundary of said first member, said first member being moveable relative to said second member such that the portion of said boundary upon which said electromagnetic radiation is directed is changed, said method including the further step of moving said boundary to change said portion of said boundary, and detecting changes in the intensity of an interference pattern produced by one portion of said boundary with an interference pattern produced by another portion of said boundary.

Claim 58

Apparatus according to claim 51 wherein said means for producing said first diffraction wave and said means for producing said second diffraction wave are spaced a distance in the direction of said axis of said interference pattern.

Claim 59

Apparatus according to claim 51 wherein said first diffraction wave producing means comprises a member in contact with an object for determining motion of the object.

Claim 60

Apparatus according to claim 51 including means for directing said electromagnetic radiation onto said first and second diffraction wave producing means stroboscopically.

Claim 61

Apparatus according to claim 51 wherein said detection means comprises two adjacent detectors spaced in the direction of fringe spacing of said interference pattern and centered about the location of said detection means.