US3728009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase filter combination with lens optics
Assignee: Inventors and Investors Inc
•
Filing: 1971-11-02
•
Granted: 1973-04-17
•
Expires: 1991-11-02
Abstract
Abstract A zonal phase filter is combined with a lens optics to produce a circular image of a point light source. Integration of the phase filter with zone plate optics is described.
Inventors
- 👤 A Fedotowsky
- 👤 K Lehovec
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:08
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1876; G02B5/189; G02B5/1895
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
115 words
An optical system comprising conventional optical means for imaging monochromatic radiation into a first image, in combination with a phase shift filter comprising a sequence of zones, each zone consisting of one section of a first kind and a laterally displaced section of a second kind, a phase difference of pi , i.e., half a wavelength, between rays passing through adjoining said zone sections of the first and second kind; the widths of said sections dimensioned to suppress the intensity of said radiation from said first image, and to shift that suppressed intensity into a second image, said second image laterally spaced from said first image, said first image located centrally to said second image.
Claim 2
Dependent Claim
115 words
An optical system comprising conventional optical means for imaging monochromatic radiation into a first image, in combination with a phase shift filter comprising a sequence of zones, each zone consisting of one section of a first kind and a laterally displaced section of a second kind, a phase difference of pi , i.e., half a wavelength, between rays passing through adjoining said zone sections of the first and second kind; the widths of said sections dimensioned to suppress the intensity of said radiation from said first image, and to shift that suppressed intensity into a second image, said second image laterally spaced from said first image, said first image located centrally to said second image.
Claim 3
Dependent Claim
20 words
The optical system of claim 1 whereby said phase shift filter is integrated with said conventional optical means for imaging.
Claim 4
Dependent Claim
30 words
The optical system of claim 2 whereby said conventional optical means for imaging is a lens and said phase filter is located on one of the surfaces of said lens.
Claim 5
Dependent Claim
42 words
The optical system of claim 2 whereby said conventional optical means for imaging and said phase shift filter have circular symmetry and are concentrically aligned, said first image being an image point, said second image being a ring surrounding said image point.
Claim 6
Dependent Claim
74 words
The optical system of claim 4 whereby said sections of said phase shift filter are bounded by radii rl (l 1, 2, . . .), selected to coincide substantially with the location of zeros of the Bessel function Jo(r1 pi xo/ lambda F) where xo is the distance from the optical axis of said ring-shaped image, lambda is the wavelength of the radiation and F is the focal length of said conventional optical means.
Claim 7
Dependent Claim
47 words
The optical system of claim 4 whereby said sections of said phase shift filter are bounded by radiI rl la/2M, where l 1, 2, . . . . 2M, whereby 2M is the number of regions of said phase shift filter and a is its aperture radius.
Claim 8
Dependent Claim
18 words
The optical system of claim 1 whereby said conventional optical means for imaging is a zone plate lens.
Claim 9
Dependent Claim
45 words
The optical system of claim 7 whereby said zone plate lens comprises a first set of sections and a second set of sections, the sections of said first set having phase shifts pi , i.e., of lambda /2 against the sections of said second set.
Claim 10
Dependent Claim
71 words
The optical system of claim 8, said phase filter and zone plate lens forming an integral unit, said unit consisting of at least portions of zone plate lens sections of said first set being replaced by corresponding portions of said second set, and at least portions of sections of said second set by corresponding portions of said first set within the sections of said first kind of said phase shift filter.
Claim 11
Dependent Claim
68 words
The optical system of claim 1, whereby said conventional optical means is a cylindrical optical means, said first image is a line, said sections of said phase shift filter are bounded by straight lines extending in direction parallel to the axis of said cylindrical optical means, said second image consisting of two lines parallel to said first image and located one at each side of said first image.
Claim 12
Dependent Claim
15 words
The optical system of claim 10 whereby said cylindrical optical means is a parabolic mirror.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |