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US 12,617,020 B2Granted
Precision freeform structuring for the fabrication of coded lenses
AssigneeNorthwestern University
InventorsPing Guo, Yaoke Wang
Life of this patent
Estimating the term…
Abstract
A system for fabricating coded lenses includes a cutting tool configured to controllably cut a workpiece at a specified position-dependent depth while traversing a surface of the workpiece along a specified two-dimensional path. A signal generator is operative to generate a signal for controlling fabrication of a coded lens from the workpiece. A vibration tool is operative to ultrasonically vibrate the cutting tool for cutting of gratings on the workpiece.
Claims17
A system for fabricating coded lenses comprising:
- a cutting tool configured to controllably cut a workpiece at a specified position-dependent depth while traversing a surface of the workpiece along a specified two-dimensional path;
- a signal generator operative to generate a signal for controlling fabrication of a coded lens from the workpiece;
- and
- a vibration tool operative to ultrasonically vibrate the cutting tool for cutting of gratings on the workpiece, wherein the cutting tool is configured to machine a freeform surface and fabricate a variable grating on the machined freeform surface;
- and
- a processor configured to control the cutting tool and the vibration tool for machining a freeform lens from the workpiece, wherein computing the three-dimensional freeform surface is based on a Chebyshev polynomial
- Z
- =
- f
- z
- (
- X
- ,
- Y
- )
- =
- -
- (
- c
-
- (
- X
- 2
- +
- Y
- 2
- )
- 1
- +
- 1
- +
- c
- 2
- (
- X
- 2
- +
- Y
- 2
- )
- +
- ∑
- i
- =
- 0
- I
- ∑
- j
- =
- 0
- J
- C
- ij
-
- T
- i
- (
- X
- L
- x
- )
-
- T
- j
- (
- X
- L
- y
- )
- +
- Z
- 0
- T
- i
- (
- x
- )
- =
- cos
-
- (
- i
-
- arccos
-
- x
- )
- ,
- where x, y, z are global coordinates, X, Y, Z are workpiece coordinates, ρ, θ are workpiece polar coordinates, Z=fz(X,Y) is a freeform surface function, Z0 is a reference depth, Ti (x) is a ith order Chebyshev polynomials at x, Cij is a 2-D Chebyshev polynomials coefficient, i, j are a order of Chebyshev polynomials, I, J are a maximum order of Chebyshev polynomials, c is a curvature of toric term.
86 more elements
A method for fabricating coded lenses comprising:
- generating a signal for controlling fabrication of a coded lens from a workpiece;
- causing a cutting tool to traverse a surface of the workpiece along a specified two-dimensional path, based on the signal;
- controllably cutting a workpiece at a specified position-dependent depth while traversing the surface of the workpiece along the specified two-dimensional path, based on the signal;
- and
- ultrasonically vibrating the cutting tool for cutting gratings on the workpiece;
- and
- computing a three-dimensional freeform surface for machining a freeform lens from the workpiece, wherein computing the three-dimensional freeform surface is based on a Chebyshev polynomial
- Z
- =
- f
- z
- (
- X
- ,
- Y
- )
- =
- -
- (
- c
-
- (
- X
- 2
- +
- Y
- 2
- )
- 1
- +
- 1
- -
- c
- 2
- (
- X
- 2
- +
- Y
- 2
- )
- +
- ∑
- i
- =
- 0
- I
- ∑
- j
- =
- 0
- J
- C
- ij
-
- T
- i
- (
- X
- L
- x
- )
-
- T
- j
- (
- X
- L
- y
- )
- +
- Z
- 0
- T
- i
- (
- x
- )
- =
- cos
-
- (
- i
-
- arccos
-
- x
- )
- where x, y, z are global coordinates, X, Y, Z are workpiece coordinates, ρ, θ are workpiece polar coordinates, Z=fz(X,Y) is a freeform surface function, Z0 is a reference depth, Ti (x) is a ith order Chebyshev polynomials at x, Cij is a 2-D Chebyshev polynomials coefficient, i, j are a order of Chebyshev polynomials, I, J are a maximum order of Chebyshev polynomials, c is a curvature of toric term.
86 more elements
A non-transitory machine-readable storage medium having instructions stored thereon for causing a processor to execute the method:
- generating a signal for controlling fabrication of a coded lens from a workpiece;
- causing a cutting tool to traverse a surface of the workpiece along a specified two-dimensional path, based on the signal;
- controllably cutting a workpiece at a specified position-dependent depth while traversing the surface of the workpiece along the specified two-dimensional path, based on the signal;
- ultrasonically vibrating the cutting tool for cutting gratings on the workpiece;
- and
- computing a three-dimensional freeform surface for machining a freeform lens from the workpiece, wherein computing the three-dimensional freeform surface is based on a Chebyshev polynomial
- Z
- =
- f
- z
- (
- X
- ,
- Y
- )
- =
- -
- (
- c
-
- (
- X
- 2
- +
- Y
- 2
- )
- 1
- +
- 1
- -
- c
- 2
- (
- X
- 2
- +
- Y
- 2
- )
- +
- ∑
- i
- =
- 0
- I
- ∑
- j
- =
- 0
- J
-
- C
- ij
-
- T
- i
- (
- X
- L
- x
- )
-
- T
- j
- (
- Y
- L
- y
- )
- )
- +
- Z
- 0
- ,
- T
- i
- (
- x
- )
- =
- cos
-
- (
- i
-
- arc
-
- cos
-
- x
- )
- where x, y, z are global coordinates, X, Y, Z are workpiece coordinates, ρ, θ are workpiece polar coordinates, Z=fz(X,Y) is a freeform surface function, Z0 is a reference depth, Ti (x) is a ith order Chebyshev polynomials at x, Cij is a 2-D Chebyshev polynomials coefficient, i, j are a order of Chebyshev polynomials, I, J are a maximum order of Chebyshev polynomials, c is a curvature of toric term.
90 more elements
Dependencies are inferred from the claim text.