US4728196A
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US
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Arrangement for determining a surface structure, especially for roughness
Assignee: Optische Werke G Rodenstock
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Filing: 1984-02-09
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Granted: 1988-03-01
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Expires: 2004-02-09
Abstract
Abstract An arrangement for determining the surface structure and especially the roughness of a specimen which includes an image lens system that focuses a parallel ray onto the surface to be examined with an inclined incidence direction and a lens system which reproduces the reflected light beam on a detector array. The distance of the detector array is approximately equal to the focal distance of the lens system. The distance of the surface from the lens systems is also approximately equal to the focal distance of the lens systems. The arrangement according to the invention offers the advantage that also with an areal specimen illumination as well as with greater changes of the distance between the arrangement and the surface to be examined, an unequivocal coordination exists between the angle, under which the light is reflected, and the individual detector elements.
Inventors
- 👤 Oskar Gerstorfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:13
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/303
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
233 words
An arrangement for determining at least a surface structure of a specimen in which angular dependence of radiant energy reflected from said surface structure for angles about a reflection angle of an ideal surface is measured, comprising a detector array means comprised of a plurality of individual detectors sensing radiant energy received from said surface structure for producing output signals, first lens means having a focal distance and whose distance from said surface structure of the specimen is approximately equal to said focal distance of said first lens means for focusing a substantially parallel radiant energy beam received from a radiant energy source onto said specimen in such a manner that an axis of the said focussed light beam subtends an angle not equal to zero with respect to a line substantially perpendicular to said surface structure of the specimen, second lens means receiving radiant energy at multiple angles of reflection from said surface structure and having a focal distance substantially equal to the distance between said second lens means and said detector array means and, for plural angles of said multiple angles of reflection imaging at a predetermined location on the radiant energy detector array means radiant energy reflected from said surface structure at a given angle of reflection, and an evaluator circuit responsive to said output signals from said individual detectors for calculating measurement elements for roughness of the surface structure.
Claim 2
Dependent Claim
233 words
An arrangement for determining at least a surface structure of a specimen in which angular dependence of radiant energy reflected from said surface structure for angles about a reflection angle of an ideal surface is measured, comprising a detector array means comprised of a plurality of individual detectors sensing radiant energy received from said surface structure for producing output signals, first lens means having a focal distance and whose distance from said surface structure of the specimen is approximately equal to said focal distance of said first lens means for focusing a substantially parallel radiant energy beam received from a radiant energy source onto said specimen in such a manner that an axis of the said focussed light beam subtends an angle not equal to zero with respect to a line substantially perpendicular to said surface structure of the specimen, second lens means receiving radiant energy at multiple angles of reflection from said surface structure and having a focal distance substantially equal to the distance between said second lens means and said detector array means and, for plural angles of said multiple angles of reflection imaging at a predetermined location on the radiant energy detector array means radiant energy reflected from said surface structure at a given angle of reflection, and an evaluator circuit responsive to said output signals from said individual detectors for calculating measurement elements for roughness of the surface structure.
Claim 3
Dependent Claim
50 words
An arrangement according to claim 1, wherein said first lens means and said second lens means comprise an integral lens system operable to focus said substantially parallel radiant energy beam onto said surface structure of the specimen and the reflected radiant energy beam onto the radiant energy detector array means.
Claim 4
Dependent Claim
20 words
An arrangement according to claim 2, wherein the detector array means comprises a line-configured arrangement of radiant energy detection means.
Claim 5
Dependent Claim
14 words
An arrangement according to claim 3, wherein the radiant energy detection means are photodiodes.
Claim 6
Dependent Claim
32 words
An arrangement according to claim 14, further comprising means for rotating during measurements the line-configured arrangement of radiant energy detection means with respect to said radiant energy, reflected from said surface structure.
Claim 7
Dependent Claim
30 words
An arrangement according to claim 4, further comprising an optical rotating means for rotating said radiant energy reflected from said surface structure with respect to the radiant energy detection means.
Claim 8
Dependent Claim
20 words
An arrangement according to claim 1, wherein the detector array means comprises a line-configured arrangement of radiant energy detection means.
Claim 9
Dependent Claim
32 words
An arrangement according to claim 7, further comprising means for rotating during measurements the line-configured arrangement of radiant energy detection means with respect to said radiant energy reflected from said surface structure.
Claim 10
Dependent Claim
30 words
An arrangement according to claim 7, further comprising an optical rotating means for rotating said radiant energy reflected from said surface structure with respect to the radiant energy detection means.
Claim 11
Dependent Claim
14 words
An arrangement according to claim 9, wherein said optical rotating means includes prism means.
Claim 12
Dependent Claim
14 words
An arrangement according to claim 10, wherein the radiant energy detection means are photodiodes.
Claim 13
Dependent Claim
75 words
An arrangement according to claim 7, wherein said first lens means comprises a collimator receiving radiant energy from said source to transmit a substantially parallel radiant energy beam to be focussed on said surface structure, and wherein the relationship of the focal distances of the collimator and at least one of said first and second lens means are variable for changing the size of the radiant energy spot on said surface structure of said specimen.
Claim 14
Dependent Claim
67 words
An arrangement according to claim 7, further comprising a collimator receiving radiant energy from said source to transmit a substantially parallel radiant energy beam, means for focussing the parallel radiant energy beam on said surface structure, and wherein distance between the collimator and the radiant energy source is variable for changing the size of the radiant energy spot on said surface of the specimen to be examined.
Claim 15
Dependent Claim
13 words
An arrangement according to claim 1, wherein the detector array means comprises photodiodes.
Claim 16
Dependent Claim
32 words
An arrangement according to claim 14, further comprising means for rotating during measurements the line-configured arrangement of radiant energy detection means with respect to said radiant energy reflected from said surface structure.
Claim 17
Dependent Claim
67 words
An arrangement according to claim 1, further comprising means comprising a collimator for receiving radiant energy to produce a substantially parallel radiant energy beam to said surface structure, and wherein the relationship of the focal distances of the collimator and at least one of said first and second lens means are variable for changing the size of the light spot on said surface structure of said specimen.
Claim 18
Dependent Claim
60 words
An arrangement according to claim 1, further comprising a collimator receiving radiant energy from said source to transmit a substantially parallel radiant energy beam to said surface structure, and wherein the distance between the collimator and the radiant energy source is variable for changing the size of the radiant energy spot on said surface of the specimen to be examined.
Claim 19
Dependent Claim
58 words
An arrangement in accordance with claim 1, wherein said plurality of detectors are disposed in plural rows as an array, each of the rows respectively having an axis, the axes of the rows being disposed substantially orthogonally with respect to a line connecting substantially a center of the array and an optical axis of said second lens means.
Claim 20
Dependent Claim
98 words
An arrangenent in accordance with claim 1, wherein the evaluation circuit determines from the output signals of the individual detectors the roughness of the surface according to the equations: ##EQU2## whereby w i is the angle of the scattered beam detected by the respective measuring element, n is the number of the detectors used for the evaluation, w is the average value from the value P I and w i , P i is the measurement signal D i defined according to the equation (c), and g i are correcting factors for the measurement signal D i .
Claim 21
Dependent Claim
178 words
Apparatus for determining a surface structure of a surface comprising a radiant energy source means for transmitting parallel rays of energy, a lens means having a first focal distance facing said surface structure and focussing said transmitted energy on said surface structure, an axis of said focussed energy being at an angle not equal to zero with respect to a line substantially perpendicular to said surface structure, a radiant energy detector array means organized of a plurality of individual detectors for receiving radiant energy reflected at plural angles of reflection to image energy reflected from said surface structure for a given angle of reflection at substantially a same location on said radiant energy detector array means for producing output signals, means for projecting the radiant energy reflected from the surface structure of a given angle of deflection onto a predetermined location of the radiant energy detector array substantially independent of the distance of the surface, and an evaluator circuit resposive to said output signals from said individual detectors for calculating measurement elements for roughness of the surface structure.
Claim 22
Dependent Claim
178 words
Apparatus for determining a surface structure of a surface comprising a radiant energy source means for transmitting parallel rays of energy, a lens means having a first focal distance facing said surface structure and focussing said transmitted energy on said surface structure, an axis of said focussed energy being at an angle not equal to zero with respect to a line substantially perpendicular to said surface structure, a radiant energy detector array means organized of a plurality of individual detectors for receiving radiant energy reflected at plural angles of reflection to image energy reflected from said surface structure for a given angle of reflection at substantially a same location on said radiant energy detector array means for producing output signals, means for projecting the radiant energy reflected from the surface structure of a given angle of deflection onto a predetermined location of the radiant energy detector array substantially independent of the distance of the surface, and an evaluator circuit resposive to said output signals from said individual detectors for calculating measurement elements for roughness of the surface structure.
Claim 23
Dependent Claim
52 words
Apparatus in accordance with claim 20, wherein said lens means comprises a first lens focusing only energy received from said radiant energy source means on said surface, and wherein said projecting means comprises a second lens means imaging only energy reflected from said surface structure on said radiant energy detector array means.
Claim 24
Dependent Claim
61 words
Apparatus in accordance with claim 20, wherein said radiant energy detector array means comprises a plurality of individual detection means disposed linearly, a first of said individual detection means receiving energy reflected at said principle angle and at least one of said remaining individual detection means receiving energy reflected at said angle of reflection other than said principle angle of reflection.
Claim 25
Dependent Claim
22 words
Apparatus in accordance with claim 20, wherein the radiant energy detector array means provides a determination of an areal scattered light distribution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
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