US3776633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of exposure for ghost line suppression
Assignee: International Business Machines Corp
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Filing: 1972-02-10
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Granted: 1973-12-04
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Expires: 1992-02-10
Abstract
Abstract A photographic method and apparatus for exposing a light sensitive layer using a mask spaced from said layer while avoiding ''''ghost lines'''' due to diffraction effects in the developed pattern on the layer. The mask is illuminated by pairs of collimated ray sets, either sequentially or simultaneously, at an angle relative to each other so that the constituent diffraction pattern on the light sensitive layer resulting from one ray set of a pair is shifted with respect to the constituent diffraction pattern attributable to the other ray set of the pair. The shift is such that the ratio of the ''''ghost line'''' intensity to the maximum intensity in the composite diffraction pattern is reduced relative to the corresponding ratio in each of the constituent diffraction patterns. The pairs of ray sets are produced by spacially displaced fixed light sources or by a rotating optical system using a single light source.
Inventors
- 👤 A Frosch
- 👤 A Schmackpfeffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:33
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70075; G02; G02B; G02B27/00; G02B27/58; G03F7/20; G03F7/2002; G03F7/201; G03F7/70091; G03F7/70208; G03F7/70216; G03F7/7035; G03F7/70483; G03F7/7055; G03F7/70583
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
138 words
The method of exposing a light sensitive layer to a very finely structured pattern of light comprising: providing a pair of collimated ray sets, providing a mask having said pattern and through which said layer is exposed by said ray sets, and directing each said ray set at said layer through said mask along a respective direction of incidence and at a respective angle of incidence relative to said mask, each said ray set producing a respective diffraction pattern occurring in the plane of said layer, each said angle of each said ray set being selected so that the diffraction patterns resulting from said pair of collimated ray sets and occurring in the plane of said layer are shifted relative to each other by about half the distance of two neighboring side maxima of each said diffraction pattern.
Claim 2
Independent Claim
138 words
The method of exposing a light sensitive layer to a very finely structured pattern of light comprising: providing a pair of collimated ray sets, providing a mask having said pattern and through which said layer is exposed by said ray sets, and directing each said ray set at said layer through said mask along a respective direction of incidence and at a respective angle of incidence relative to said mask, each said ray set producing a respective diffraction pattern occurring in the plane of said layer, each said angle of each said ray set being selected so that the diffraction patterns resulting from said pair of collimated ray sets and occurring in the plane of said layer are shifted relative to each other by about half the distance of two neighboring side maxima of each said diffraction pattern.
Claim 3
Dependent Claim
13 words
The method defined in claim 1 wherein said ray sets are employed simultaneously.
Claim 4
Dependent Claim
13 words
The method defined in claim 1 wherein said ray sets are employed successively.
Claim 5
Dependent Claim
14 words
The method defined in claim 1 wherein each said ray set is substantially monochromatic.
Claim 6
Dependent Claim
15 words
The method defined in claim 1 wherein each said angle of incidence is the same.
Claim 7
Dependent Claim
64 words
The method defined in claim 5 wherein said ray sets are produced by rotating a single ray set about an axis normal to the plane of said mask so that the direction of incidence of said single ray set relative to said mask is changed but the angle of incidence of said single ray set relative to said mask is unchanged during the rotation.
Claim 8
Dependent Claim
136 words
Apparatus for exposing a light sensitive layer to a very finely structured light pattern comprising: a pair of collimated ray sets, a mask having said pattern and through which said layer is exposed by said ray sets, and means for directing each said ray set at said layer through said mask along a respective direction of incidence and at a respective angle of incidence relative to said mask, each said ray set producing a respective diffraction pattern occurring in the plane of said layer, each said angle of each said ray set being selected so that the diffraction patterns resulting from said pair of collimated ray sets and occurring in the plane of said layer are shifted relative to each other by about half the distance of two neighboring side maxima of each said diffraction pattern.
Claim 9
Dependent Claim
136 words
Apparatus for exposing a light sensitive layer to a very finely structured light pattern comprising: a pair of collimated ray sets, a mask having said pattern and through which said layer is exposed by said ray sets, and means for directing each said ray set at said layer through said mask along a respective direction of incidence and at a respective angle of incidence relative to said mask, each said ray set producing a respective diffraction pattern occurring in the plane of said layer, each said angle of each said ray set being selected so that the diffraction patterns resulting from said pair of collimated ray sets and occurring in the plane of said layer are shifted relative to each other by about half the distance of two neighboring side maxima of each said diffraction pattern.
Claim 10
Dependent Claim
17 words
Apparatus as defined in claim 7 wherein said respective directions of incidence are transverse to each other.
Claim 11
Dependent Claim
15 words
Apparatus as defined in claim 7 wherein each said angle of incidence is the same.
Claim 12
Dependent Claim
67 words
Apparatus as defined in claim 9 and further including: means for producing said ray sets by rotating a single ray set about an axis normal to the plane of said mask so that the direction of incidence of said single ray set relative to said mask is changed but the angle of incidence of said single ray set relative to said mask is unchanged during the rotation.
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) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |