Doppler velocimeter

Claim 1

An apparatus for detecting the velocity information light source means; of an object, comprising: frequency shifting means for shifting the frequency of a light flux from the light source means, said frequency shifting means having a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; light-flux dividing means for dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by the light-flux dividing means being projected onto an object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different from said first and second positions; first detection means for detecting light from the object to be measured to which said third and fifth light fluxes are projected, the light detected by the first detection means having undergone a Doppler shift relative to the velocity of the object to be measured; second detection means for detecting light generated by combining said fourth and sixth light fluxes at said position for combining; and velocity information detection means for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detection means.

Claim 2

An apparatus for detecting the velocity information light source means; of an object, comprising: frequency shifting means for shifting the frequency of a light flux from the light source means, said frequency shifting means having a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; light-flux dividing means for dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by the light-flux dividing means being projected onto an object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different from said first and second positions; first detection means for detecting light from the object to be measured to which said third and fifth light fluxes are projected, the light detected by the first detection means having undergone a Doppler shift relative to the velocity of the object to be measured; second detection means for detecting light generated by combining said fourth and sixth light fluxes at said position for combining; and velocity information detection means for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detection means.

Claim 6

An apparatus for detecting the velocity information of an object, comprising: light source means; frequency shifting means for shifting the frequency of a light flux from the light source means; light-flux dividing means for dividing a light flux whose frequency is divided by the frequency shifting means, one of the light fluxes divided by the light-flux dividing means being projected onto an object to be measured and the other light flux being projected in a direction other than that of said one of the light fluxes; first detecting means for detecting light from the object to be measured to which said one of the light fluxes is projected, the light detected by the first detection means having undergone a Doppler shift relative to the velocity of the object to be measured; second detection means for detecting the other light flux; velocity information detection means for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detection means; and a diffraction grating by means of which a light flux from said light source means is divided, wherein said frequency shifting means shifts the frequency of the first and second light fluxes, which are light fluxes divided by said diffraction grating, wherein the light-flux dividing means further divides the first light flux into a third and a fourth light flux, and further divides the second light flux into a fifth and a sixth light flux, wherein the first detection means detects light from the intersection section of the third and the fifth light fluxes on the object to be measured, and wherein the second detection means detects light from the intersection section of the fourth and the sixth light fluxes.

Claim 7

An apparatus for detecting the velocity information of an object, comprising: light source means; frequency shifting means for shifting the frequency of a light flux from the light source means; light-flux dividing means for dividing a light flux whose frequency is divided by the frequency shifting means, one of the light fluxes divided by the light-flux dividing means being projected onto an object to be measured and the other light flux being projected in a direction other than that of said one of the light fluxes; first detecting means for detecting light from the object to be measured to which said one of the light fluxes is projected, the light detected by the first detection means having undergone a Doppler shift relative to the velocity of the object to be measured; second detection means for detecting the other light flux; velocity information detection means for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detection means; and a diffraction grating by means of which a light flux from said light source means is divided, wherein said frequency shifting means shifts the frequency of the first and second light fluxes, which are light fluxes divided by said diffraction grating, wherein the light-flux dividing means further divides the first light flux into a third and a fourth light flux, and further divides the second light flux into a fifth and a sixth light flux, wherein the first detection means detects light from the intersection section of the third and the fifth light fluxes on the object to be measured, and wherein the second detection means detects light from the intersection section of the fourth and the sixth light fluxes.

Claim 11

A method of detecting velocity information of an object, comprising the steps of: shifting the frequency of a light flux, said shifting being performed by using a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by said light flux division being projected onto the object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different than said first and second positions; performing a first detection whereby light from the object to be measured to which the third and fifth light fluxes are projected is detected, said light having undergone a Doppler shift proportional to the velocity of the object to be measured; performing a second detection whereby light generated by combining said fourth and sixth light fluxes at said position for combining the other light flux at said position for combining the other light flux is detected; and detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detections.

Claim 12

A method of detecting velocity information of an object, comprising the steps of: shifting the frequency of a light flux, said shifting being performed by using a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by said light flux division being projected onto the object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different than said first and second positions; performing a first detection whereby light from the object to be measured to which the third and fifth light fluxes are projected is detected, said light having undergone a Doppler shift proportional to the velocity of the object to be measured; performing a second detection whereby light generated by combining said fourth and sixth light fluxes at said position for combining the other light flux at said position for combining the other light flux is detected; and detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals of the first and second detections.

Claim 15

A method of detecting velocity information of an object, comprising the steps of: shifting the frequency of a light flux; dividing the light flux whose frequency has been shifted, one of the light fluxes divided by said light flux division being projected onto the object to be measured and the other light flux being projected in a direction other than that of said one of the light fluxes. performing a first detection whereby light from the object to be measured to which one of the light fluxes is projected is detected, said light having undergone a Doppler shift proportional to the velocity of the object to be measured, performing a second detection whereby the other light flux is detected, and detecting the velocity information of the object to be measured on the basis of a comparison between detection signals of the first and second detections, wherein a light flux from a light source is divided by a diffraction grating prior to the frequency shifting step, wherein said frequency shifting includes shifting the frequency of the first and second light fluxes, which are light fluxes divided by said diffraction grating, wherein the light-flux dividing further divides the first light flux into a third and a fourth light flux, and further divides the second light flux into a fifth and a sixth light flux, wherein the first detection detects light from the intersection section of the third and the fifth light fluxes on the object to be measured, and wherein the second detection detects light from the intersection section of the fourth and the sixth light fluxes.

Claim 16

A method of detecting velocity information of an object, comprising the steps of: shifting the frequency of a light flux; dividing the light flux whose frequency has been shifted, one of the light fluxes divided by said light flux division being projected onto the object to be measured and the other light flux being projected in a direction other than that of said one of the light fluxes. performing a first detection whereby light from the object to be measured to which one of the light fluxes is projected is detected, said light having undergone a Doppler shift proportional to the velocity of the object to be measured, performing a second detection whereby the other light flux is detected, and detecting the velocity information of the object to be measured on the basis of a comparison between detection signals of the first and second detections, wherein a light flux from a light source is divided by a diffraction grating prior to the frequency shifting step, wherein said frequency shifting includes shifting the frequency of the first and second light fluxes, which are light fluxes divided by said diffraction grating, wherein the light-flux dividing further divides the first light flux into a third and a fourth light flux, and further divides the second light flux into a fifth and a sixth light flux, wherein the first detection detects light from the intersection section of the third and the fifth light fluxes on the object to be measured, and wherein the second detection detects light from the intersection section of the fourth and the sixth light fluxes.

Claim 22

An apparatus for detecting velocity information of an object, comprising: a light source; a frequency shifter for shifting the frequency of a light flux from the light source, said frequency shifter having a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; at least one beam splitter for dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by said light flux division being projected onto the object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different from said first and second positions; a first photodetector for detecting the light from the object to be measured to which said third and fifth light fluxes are projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining said fourth and sixth light fluxes at said position for combining; and a detection circuit for detecting the velocity information of the object to be measured on the basis of the comparison of frequency between detection signals from the first and second photodetectors.

Claim 23

An apparatus for detecting velocity information of an object, comprising: a light source; a frequency shifter for shifting the frequency of a light flux from the light source, said frequency shifter having a diffraction grating moving along a predetermined direction, said diffraction grating generating a first light flux whose frequency is shifted and a second light flux directed differently from said first light flux; at least one beam splitter for dividing said first light flux into third and fourth light fluxes at a first position and said second light flux into fifth and sixth light fluxes at a second position, said third and fifth light fluxes divided by said light flux division being projected onto the object to be measured and said fourth and sixth light fluxes being projected on a position for combining said fourth and sixth light fluxes different from said first and second positions; a first photodetector for detecting the light from the object to be measured to which said third and fifth light fluxes are projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining said fourth and sixth light fluxes at said position for combining; and a detection circuit for detecting the velocity information of the object to be measured on the basis of the comparison of frequency between detection signals from the first and second photodetectors.

Claim 25

An apparatus for detecting velocity information of an object, comprising: a system for generating two light beams directed in different directions from each other and each having a different frequency from each other, said two light beams enabling generation of a beat signal by interfering with each other; an optical system for splitting one of said two light beams into a pair of split beams at a first position and the other of said two light beams into a pair of split beams at a second position, said optical system directing at least one of the split beams from the first position and one of the split beams from the second position to an object to be measured, and further directing the other split beam from the first position and the other split beam from the second position to a third position different from said first and second positions for combining the other split beams; a first photodetector for detecting interference light generated by combining said split beams including a beam from the object to be measured to which at least one of said split beams is projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining the other split beams at said third position; and a detection circuit for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals from the first and second photodetectors.

Claim 26

An apparatus for detecting velocity information of an object, comprising: a system for generating two light beams directed in different directions from each other and each having a different frequency from each other, said two light beams enabling generation of a beat signal by interfering with each other; an optical system for splitting one of said two light beams into a pair of split beams at a first position and the other of said two light beams into a pair of split beams at a second position, said optical system directing at least one of the split beams from the first position and one of the split beams from the second position to an object to be measured, and further directing the other split beam from the first position and the other split beam from the second position to a third position different from said first and second positions for combining the other split beams; a first photodetector for detecting interference light generated by combining said split beams including a beam from the object to be measured to which at least one of said split beams is projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining the other split beams at said third position; and a detection circuit for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals from the first and second photodetectors.

Claim 28

An apparatus for detecting velocity information of an object, comprising: a system for generating two light beams directed in different directions from each other each having a different frequency from each other, said two light beams enabling generation of a beat signal by interfering with each other; an optical system for splitting one of said two light beams into a first pair of split beams and the other of said two light beams into a second pair of split beams, said optical system directing one split beam of the first pair of split beams and one split beam of the second pair of split beams to an object to be measured, and further directing the other split beam of the first pair of split beams and the other split beam of the second pair of split beams in respective directions for combining the other split beams, said optical system being arranged so that optical paths of said two light beams are almost symmetric and optical paths of said first pair of split beams and optical paths of said second pair of split beams are almost symmetric; a first photodetector for detecting light from the object to be measured to which said split beams are projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining the other split beams at said third position; and a detection circuit for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals from the first and second photodetectors.

Claim 29

An apparatus for detecting velocity information of an object, comprising: a system for generating two light beams directed in different directions from each other each having a different frequency from each other, said two light beams enabling generation of a beat signal by interfering with each other; an optical system for splitting one of said two light beams into a first pair of split beams and the other of said two light beams into a second pair of split beams, said optical system directing one split beam of the first pair of split beams and one split beam of the second pair of split beams to an object to be measured, and further directing the other split beam of the first pair of split beams and the other split beam of the second pair of split beams in respective directions for combining the other split beams, said optical system being arranged so that optical paths of said two light beams are almost symmetric and optical paths of said first pair of split beams and optical paths of said second pair of split beams are almost symmetric; a first photodetector for detecting light from the object to be measured to which said split beams are projected, the light detected by the first photodetector having undergone a Doppler shift proportional to the velocity of the object to be measured; a second photodetector for detecting light generated by combining the other split beams at said third position; and a detection circuit for detecting the velocity information of the object to be measured on the basis of a comparison of frequency between detection signals from the first and second photodetectors.