US5068751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three element grating objective and grating-beam shaper, and optical scanning device
Assignee: US Philips Corp
•
Filing: 1990-08-17
•
Granted: 1991-11-26
•
Expires: 2010-08-17
Abstract
Abstract A grating objective comprises at least three gratings and in which an axial ray and a border ray of a radiation beam are interchanged at least two times so that the objective has a wavelength-independent behavior, a relatively large image field and a satifactorily uniform intensity distribution. A beam shaper and a grating objective with a built-in beam shaper are described based on the same principle.
Inventors
- 👤 Josephus J. M. Braat
- 👤 Willem G. Opheij
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:58
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1372; G11B7/1374; G11B7/1353; G02; G02B; G02B13/00; G02B27/00; G02B27/0025; G02B27/0037; G02B27/42; G02B27/4233; G02B27/4238; G02B27/4272; G02B5/00; G02B5/18; G02B5/1814; G11B7/123
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
125 words
A grating objective comprising: a first diffraction grating and a second diffraction grating arranged one behind the other in a radiation path extending from an object side to an image side, the gratings being adapted and arranged in such a way that a beam ray which is an axial ray for one grating is a border ray for the other grating and that another beam ray which is a border ray for one grating is an axial ray for the other grating, and at least a third grating arranged in the radiation path formed by the first and the second grating, so that the axial ray and the border ray of a beam traversing the grating objective are interchanged or switched at least two times.
Claim 2
Dependent Claim
125 words
A grating objective comprising: a first diffraction grating and a second diffraction grating arranged one behind the other in a radiation path extending from an object side to an image side, the gratings being adapted and arranged in such a way that a beam ray which is an axial ray for one grating is a border ray for the other grating and that another beam ray which is a border ray for one grating is an axial ray for the other grating, and at least a third grating arranged in the radiation path formed by the first and the second grating, so that the axial ray and the border ray of a beam traversing the grating objective are interchanged or switched at least two times.
Claim 3
Dependent Claim
16 words
A grating objective as claimed in claim 1, characterized in that all gratings are transmission gratings.
Claim 4
Dependent Claim
32 words
A grating objective as claimed in claim 2 comprising a built-in beam shaper, characterized in that it comprises two-dimensional gratings each having grating periods which are different in two mutually perpendicular directions.
Claim 5
Dependent Claim
52 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam and an objective system for focusing the scanning beam to a radiation spot in the information plane, characterized in that the objective system is constituted by a grating objective as claimed in claim 2.
Claim 6
Dependent Claim
92 words
A grating objective as claimed in claim 1, comprising a transparent plane-parallel plate having a first surface at the object side and a second surface at the image side and an optical axis perpendicular to the first and second surfaces, the first surface having a radiation window surrounding the optical axis, the first grating being a reflecting grating and arranged on the second grating and arranged around the radiation window on the first surface and the third grating being a radiation-transmissive grating and arranged on the second surface around the first grating.
Claim 7
Dependent Claim
32 words
A grating objective as claimed in claim 5 comprising a built-in beam shaper, characterized in that it comprises two-dimensional gratings each having grating periods which are different in two mutually perpendicular directions.
Claim 8
Dependent Claim
52 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam and an objective system for focusing the scanning beam to a radiation spot in the information plane, characterized in that the objective system is constituted by a grating objective as claimed in claim 5.
Claim 9
Dependent Claim
32 words
A grating objective as claimed in claim 1, comprising a built-in beam shaper, characterized in that it comprises two-dimensional gratings each having grating periods which are different in two mutually perpendicular directions.
Claim 10
Dependent Claim
67 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam having an elliptic cross-section, a beam shaper for reshaping the elliptic beam cross-section to a circular cross-section and an objective system for focusing the scanning beam to a scanning spot in the information plane, characterized by a grating objective comprising a built-in beam shaper as claimed in claim 8.
Claim 11
Dependent Claim
37 words
A device as claimed in claim 9, characterized in that an entrance window of the grating objective is provided with a coupling-out grating for diverting radiation returning through the objective from the path of the source radiation.
Claim 12
Dependent Claim
27 words
A device as claimed in claim 9, characterized in that the grating objective and a radiation-sensitive detection system are arranged in a housing of the radiation source.
Claim 13
Dependent Claim
52 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam and an objective system for focusing the scanning beam to a radiation spot in the information plane, characterized in that the objective system is constituted by a grating objective as claimed in claim 1.
Claim 14
Dependent Claim
37 words
A device as claimed in claim 12, characterized in that an entrance window of the grating objective is provided with a coupling-out grating for diverting radiation returning through the objective from the path of the source radiation.
Claim 15
Dependent Claim
27 words
A device as claimed in claim 13, characterized in that the grating objective and a radiation-sensitive detection system are arranged in a housing of the radiation source.
Claim 16
Dependent Claim
27 words
A device as claimed in claim 12, characterized in that the grating objective and a radiation-sensitive detection system are arranged in a housing of the radiation source.
Claim 17
Dependent Claim
73 words
A beam shaper for reshaping a beam having an elliptic cross-section to a beam having a circular-symmetrical cross-section, characterized by a system of at least three gratings which are arranged one behind the other in a path of a beam, the gratings being adapted in such a way that an axial ray and a border ray of the beam are interchanged or switched two at least times, while the gratings are one-dimensional gratings.
Claim 18
Dependent Claim
73 words
A beam shaper for reshaping a beam having an elliptic cross-section to a beam having a circular-symmetrical cross-section, characterized by a system of at least three gratings which are arranged one behind the other in a path of a beam, the gratings being adapted in such a way that an axial ray and a border ray of the beam are interchanged or switched two at least times, while the gratings are one-dimensional gratings.
Claim 19
Dependent Claim
16 words
A beam shaper as claimed in claim 16, characterized in that all gratings are transmission gratings.
Claim 20
Dependent Claim
62 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam having an elliptic cross-section, a beam shaper for reshaping the elliptic beam cross-section to a circular cross-section and an objective system for focusing the scanning beam to a scanning spot in the information plane, characterized by a beam shaper as claimed in claim 17.
Claim 21
Dependent Claim
18 words
A beam shaper as claimed in claim 16, characterized in that an even number of gratings is reflecting.
Claim 22
Dependent Claim
62 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam having an elliptic cross-section, a beam shaper for reshaping the elliptic beam cross-section to a circular cross-section and an objective system for focusing the scanning beam to a scanning spot in the information plane, characterized by a beam shaper as claimed in claim 16.
Claim 23
Dependent Claim
62 words
A device for optically scanning an information plane, which device comprises a radiation source supplying a scanning beam having an elliptic cross-section, a beam shaper for reshaping the elliptic beam cross-section to a circular cross-section and an objective system for focusing the scanning beam to a scanning spot in the information plane, characterized by a beam shaper as claimed in claim 16.
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) | 1994-11-25 | 1995-05-27 | 1995-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-25 | 1999-05-27 | 1999-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-25 | 2003-05-27 | 2003-11-26 | $7700.00 | Window Closed / Lapsed |