US3884546A
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Spectrum shaping with parity sequences
Assignee: HP Inc
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Filing: 1973-07-30
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Granted: 1975-05-20
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Expires: 1993-07-30
Abstract
Abstract A method is disclosed for shaping a Fourier transform spectrum of an array of input data. The method may be used to produce a Fourier spectrum in which the moduli of the Fourier coefficients are all equal to one predetermined constant. This makes possible hologram synthesis with phase only transmittance and is an improvement over kinoforms where amplitude information must be discarded. The present method rests on the introduction of an auxiliary parity array of data which is interlaced with the true data array to be stored, the parity array being chosen so that a Fourier spectrum of the combined data and parity arrays has a level spectrum. In an image reconstructed from the hologram, optical detectors may be positioned to detect only the reconstructed data points. Other spectrum shaping is also possible including phase quantization.
Inventors
- 👤 David C Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:31
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/042; G06; G06F; G06F17/00; G06F17/10; G06F17/14; G06F17/141
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
147 words
A method of synthesizing an output array of elements in which an input two-dimensional N X Q data array is embedded, each element of said data array being indicative of a complex number fn, q, said method comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; producing an extended spectral array of order (yN) X (zQ), y and z being integer numbers, at least one of y and z being greater than unity, each element of said extended spectral array being a complex number Gm, p having a modulus and a phase each being a preselected value, subject to a condition among the elements of said extended spectral array given by an equation to be satisified for a substantial number of Fm, p
Claim 2
Independent Claim
147 words
A method of synthesizing an output array of elements in which an input two-dimensional N X Q data array is embedded, each element of said data array being indicative of a complex number fn, q, said method comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; producing an extended spectral array of order (yN) X (zQ), y and z being integer numbers, at least one of y and z being greater than unity, each element of said extended spectral array being a complex number Gm, p having a modulus and a phase each being a preselected value, subject to a condition among the elements of said extended spectral array given by an equation to be satisified for a substantial number of Fm, p
Claim 3
Dependent Claim
28 words
A method as in claim 1 including the step of phase coding said elements fn, q of said data array before producing said discrete Fourier transform spectrum array.
Claim 4
Dependent Claim
31 words
A method as in claim 1 wherein the step of producing an extended spectral array comprises the step of producing an extended spectral array whose elements all have the same modulus.
Claim 5
Dependent Claim
28 words
A method as in claim 3 including the step of phase coding said elements fn, q of said data array before producing said discrete Fourier transform spectrum array.
Claim 6
Dependent Claim
62 words
A method as in claim 3 wherein the step of producing an extended spectral array comprises the steps of: determining a constant real number A greater than the modulus of a substantial number of Fmp of said discrete Fourier transform array; and producing an extended spectral array wherein those elements which are associated with said substantial number of elements Fmp satisfy equations
Claim 7
Dependent Claim
28 words
A method as in claim 5 including the step of phase coding said elements fn, q of said data array before producing said discrete Fourier transform spectrum array.
Claim 8
Dependent Claim
44 words
A method as in claim 1 wherein the step of producing an extended spectral array comprises the step of producing an extended spectral array wherein each element of said extended spectral array has a phase equal to one of a preselected plurality of values.
Claim 9
Independent Claim
133 words
A method of synthesizing an output array of elements in which an input two-dimensional N X Q data array is embedded, each element of said data array being indicative of a complex number fn, q, said method comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; determining a constant real number A greater than the modulus of a substantial number of elements Fmp of said discrete Fourier transform array; producing an extended spectral array of order (2N) X (2Q), each element of said extended spectral array being a complex number Gm, p and those elements which are associated with said substantial number of Fm, p satisfy the following equations:
Claim 10
Independent Claim
133 words
A method of synthesizing an output array of elements in which an input two-dimensional N X Q data array is embedded, each element of said data array being indicative of a complex number fn, q, said method comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; determining a constant real number A greater than the modulus of a substantial number of elements Fmp of said discrete Fourier transform array; producing an extended spectral array of order (2N) X (2Q), each element of said extended spectral array being a complex number Gm, p and those elements which are associated with said substantial number of Fm, p satisfy the following equations:
Claim 11
Dependent Claim
28 words
A method as in claim 8 including the step of phase coding said elements fn, q of said data array before producing said discrete Fourier transform spectrum array.
Claim 12
Independent Claim
121 words
A method for making a hologram of a two-dimensional N X Q data array comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; producing an extended spectral array of order (yN) X (zQ), y and z being integer numbers, at least one of y and z being greater than unity, each element of said extended spectral array being a complex number Gm, p having a modulus and a phase each being a preselected value, subject to a condition among the elements of said extended spectral array given by an equation satisfied for a substantial number of Fmp.
Claim 13
Independent Claim
121 words
A method for making a hologram of a two-dimensional N X Q data array comprising the steps of: producing an N X Q discrete Fourier transform spectrum array of said input data array, each element of said Fourier transform spectrum array being a complex number Fm, p; producing an extended spectral array of order (yN) X (zQ), y and z being integer numbers, at least one of y and z being greater than unity, each element of said extended spectral array being a complex number Gm, p having a modulus and a phase each being a preselected value, subject to a condition among the elements of said extended spectral array given by an equation satisfied for a substantial number of Fmp.
Claim 14
Dependent Claim
22 words
A method for making a hologram as in claim 10 including the step of phase coding the elements of said data array.
Claim 15
Dependent Claim
35 words
A method for making a hologram as in claim 10 wherein the step of producing an extended spectral array comprises the step of producing an extended spectral array whose elements all have the same modulus.
Claim 16
Dependent Claim
18 words
A method as in claim 12 including the step of phase coding the elements of said data array.
Claim 17
Dependent Claim
63 words
A method as in claim 12 wherein the step of producing an extended spectral array comprises the steps of: determining a constant real number A greater than the modulus of a substantial number of elements Fmp of said discrete Fourier transform array; and producing an extended spectral array wherein those elements which are associated with said substantial number of elements Fmp satisfy equations
Claim 18
Dependent Claim
18 words
A method as in claim 14 including the step of phase coding the elements of said data array.
Claim 19
Dependent Claim
52 words
A method for making a hologram as in claim 10 wherein the step of recording a representation of said extended spectral array comprises the steps of: displaying a representation of said extended spectral array by means of an optical display; and photographically reproducing an image of said representation onto a transparent medium.
References Cited (Backward Citations)
US3606515A
Cited
US3623786A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |