Optical: systems and elements – Compound lens system – Microscope
Reexamination Certificate
2000-12-01
2003-02-25
Robinson, Mark A. (Department: 2872)
Optical: systems and elements
Compound lens system
Microscope
C359S368000, C359S386000
Reexamination Certificate
active
06525875
ABSTRACT:
1. BACKGROUND OF THE INVENTION
This invention relates to a microscope generating a three-dimensional representation of the observed object, operating on a principle derived from “image formation by scattered field inversion”, tomography and synthetic aperture systems.
2. THE PRIOR ART
2.1. References
[Wolf]:
Three
-
Dimensional Structure Determination of Semi
-
Transparent Object from Holographic Data,
Emil Wolf, Optics Communications, Vol. 1, No. 4, p.153, October 1969.
[Dändliker]:
Reconstruction of the Three
-
Dimensional
-
Refractive Index from Scattered Waves,
R. Dändliker, K. Weiss, Optics Communications, Vol. 1, No. p.323, February 1970.
[Fercher]:
Image Formation by Inversion of Scattered Field Data: Experiments and Computational Simulation.
A. F. Fercher, H. Bartelt, H. Becker, E. Wiltschko, Applied Optics, Vol.18, No 14, p.2427, July 1979
[Kawata]:
Optical Microscope Tomography. I. Support Constraint,
S. Kawata, O. Nakamnura & S. Minami, Journal of the Optical Society of America A, Vol. 4, No.1, p.292, January 1987
[Noda]:
Three
-
Dimensional Phase
-
Contrast Imaging by a Computed
-
Tomography Microscope,
Tomoya Noda, Satoshi Kawata & Shigeo Minami, Applied Optics, Vol. 31, No. 5, p.670, Feb. 10, 1992
[Devaney]:
The Coherent Optical Tomographic Microscope,
A. J. Devaney and A. Schatzberg, SPIE, Vol.1767, p.62, 1992
[Wedberg]:
Experimental Simulation of the Quantitative Imaging Properties of Optical Diffraction Tomography,
Torolf A. Wedberg and Jacob J. Stamnes, Journal of the Optical Society of America A, Vol. 12, No 3, p.493, March 1995.
[Vishnyakov]:
Interferometric Computed
-
Microtomography of
3
D Phase Objects,
Gennady N. Vishnyakov & Gennady G. Levin, SPIE Proceedings, Vol.2984, p.64, 1997
[Ausherman]:
Developments in Radar Imaging,
D. A. Ausherman, A. Kozma, J. L. Walker, H. M. Jones, E. C. Poggio, IEEE Transactions on Aerospace and Electronic Systems, Vol. 20, No. 4, p.363, July 1984.
[Goodman]:
Synthetic Aperture Optics,
Progress in Optics, Vol. VIII, 1970, North Holland Publishing Company.
[Walker]:
Range
-
Doppler Imaging of Rotating Objects,
Jack L. Walker, IEEE transactions on Aerospace and Electronic Systems, Vol. 16, No. 1, p.23, Januasy 1980.
[Brown]:
Walker model for Radar Sensing of Rigid Target Fields,
William M. Brown, IEEE Transactions on Aerospace and Electronic Systems, Vol. 16, No 1, p.104, January 1980.
[Turpin 1]: U.S. Pat. No. 5,384,573
[Turpin 2]:
Theory of the Synthetic Aperture Microscope,
Terry Turpin, Leslie Gesell, Jeffrey Lapides, Craig Price, SPIE Proceedings, Vol. 2566, p.230, 1995
[Turpin 3
]: The Synthetic Aperture Microscope, Experimental results,
P. Woodford, T. Turpin, M. Rubin, J. Lapides, C. Price, SPIE Proceedings, Vol. 2751 p.230, 1996
[Lauer 1]: Patent WO 98/13715
2.2. Description of the Prior Art
A three-dimensional object may be characterized optically by a certain number of local parameters, for example its index and its absorptivity at each point. Mathematically, this may be expressed by the data at each point of a complex number which is a function of the local parameters at the considered point. A three-dimensional spatial representation of the object can then be expressed in the form of a three-dimensional array of complex numbers.
By carrying out the three-dimensional Fourier transform of this three-dimensional spatial representation, a three-dimensional frequency representation of the object is obtained.
[Wolf] showed that a three-dimensional representation of a weakly diffracting object can be obtained from the acquisition of the wave diffracted by this object when it is illuminated successively by a series of plane waves of variable direction. [Wolf] also determined the maximum resolution thus obtainable, expressed as a function of the illuminating wavelength. This resolution corresponds to a maximum period of &lgr;/2 for the sinusoidal components the object's representation, i.e. a sampling period in the Nyquist sense of &lgr;/4 which is a resolution twice as fine as that of conventional microscopes. [Dändliker] improved [Wolf]'s formalism and provided a geometrical interpretation of it. From the wave diffracted by the object under a given illumination, part of the three-dimensional frequency representation of the object is obtained. This part is a sphere in a three-dimensional frequency space. By combining the spheres thus obtained for various illuminating waves, the frequency space can be filled, obtaining the three-dimensional frequency representation of the object. The latter can then be inverse transformed to obtain a spatial representation.
[Fercher] designed a microscope constituting the first practical application of the principles defined by [Wolf] and [Dandliker]. In that microscope, the wave diffracted by the object is picked up on a receiving surface on which it interferes with a reference wave not having passed through the object and the phase of which can be modified. From several interference figures differing from each other by the phase of the reference wave, [Fercher] obtains, at each point of the receiving surface, the amplitude and the phase of the wave diffracted by the object.
[Fercher] does not use several successive illumination waves but several illuminating waves generated simultaneously by means of a diffraction grating, thus limiting the number of possible illumination directions, even though the use of several successive illuminating waves does not present any particular technical difficulty. The reason for this choice is not clearly explained. However, it appears that this technique is adopted in order to obtain illuminating waves all having the same phase at a given point of the image. In fact, the equation (1) of the document [Wolf] assumes that each illuminating wave has a zero phase at the point of origin of the position vectors.
The method defined by [Wolf], [Dändliker] and [Fercher] is generally called “image formation by scattered field inversion”. Another conventional approach for obtaining three-dimensional images is tomography. Tomography, used for example in x-ray techniques, consists in reconstructing an image from a set of projections of this image along different directions. Each projection depends linearly upon a three-dimensional density function characterizing the object. From a sufficient number of projections it is possible to reconstitute the object by reversing this linear correspondence.
Tomography was adapted to optical microscopy by [Kawata]. In his tomographic microscope, a plane and non-coherent illuminating wave of variable direction is used. This illuminating wave passes through a sample and then a microscope objective focussed in the plane of the sample. It is received on a receiving surface placed in the plane in which the objective forms the image of the sample. Because the illumination is non-coherent, the intensities coming from each point of the object are added and the image intensity produced on the receiving surface consequently depends linearly on the three-dimensional density function characterizing the absorptivity of the object. From a sufficient number of images it is possible to reconstitute the image by reversing this linear correspondence. This microscope differs from usual tomographic systems in that the linear correspondence between the density function of the object and a given image is not a projection, but is characterized by a three-dimensional optical transfer function.
This microscope is not very suitable for obtaining images that take into account the index of the sample. [Noda] designed a modified microscope enabling this phase to be taken into account. The initial idea of that microscope [Noda] is to use phase contrast for obtaining an image which depends on the index of th
Lauer Vincent
Robinson Mark A.
LandOfFree
Microscope generating a three-dimensional representation of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microscope generating a three-dimensional representation of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microscope generating a three-dimensional representation of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3165460