US3703641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particle-size measuring apparatus
Assignee: Boeing North American Inc
•
Filing: 1969-08-18
•
Granted: 1972-11-21
•
Expires: 1989-08-18
Abstract
Abstract This invention causes a particle to pass through an intense lightbeam, thus producing a diffraction pattern that is converted to an output signal corresponding to the particle-size. A plurality of lenses produces a minimal-size lightbeam that is blocked-out for normal states, but is permitted to produce an output signal at the presence of a particle. The optical arrangement also blocks-out lightbeams produced by dust, thus providing a better signal-to-noise ratio indication.
Inventors
- 👤 Fred D Rosen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:07
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
249 words
The combination comprising: a mask with light-transmitting elongated slit aperture, means for producing a lightbeam directed towards said mask along an optical axis, first and second crossed cylindrical lenses positioned on the proximal side of said slit aperture and on the optical axis, for converging said lightbeam in a first direction transverse to the direction of propagation of said lightbeam so that the lightbeam is focused substantially to a line on said slit aperture, and for converging said lightbeam in a second transverse direction substantially perpendicular to said first direction so that after passing through said slit aperture the lightbeam is converged at a first plane spaced from and on the distal side of said mask, the lightbeam emerging from said slit aperture being defined as a primary lightbeam, a first light-trap positioned on the optical axis at said first plane for absorbing said primary lightbeam, optical-sensor means, positioned on the optical axis on the distal side of said slit aperture and said first light-trap for producing an output-signal when a particle present in said primary lightbeam located between said mask and said first light-trap produces secondary lightbeams, a spherical lens positioned on the optical axis between said slit aperture and said optical sensor means, for imagining said slit aperture at a second plane on the distal side of said spherical lens, a second light-trap positioned on the optical axis at said second plane for absorbing tertiary lightbeams produced by dust and the like, and traversing said slit aperture.
Claim 2
Dependent Claim
249 words
The combination comprising: a mask with light-transmitting elongated slit aperture, means for producing a lightbeam directed towards said mask along an optical axis, first and second crossed cylindrical lenses positioned on the proximal side of said slit aperture and on the optical axis, for converging said lightbeam in a first direction transverse to the direction of propagation of said lightbeam so that the lightbeam is focused substantially to a line on said slit aperture, and for converging said lightbeam in a second transverse direction substantially perpendicular to said first direction so that after passing through said slit aperture the lightbeam is converged at a first plane spaced from and on the distal side of said mask, the lightbeam emerging from said slit aperture being defined as a primary lightbeam, a first light-trap positioned on the optical axis at said first plane for absorbing said primary lightbeam, optical-sensor means, positioned on the optical axis on the distal side of said slit aperture and said first light-trap for producing an output-signal when a particle present in said primary lightbeam located between said mask and said first light-trap produces secondary lightbeams, a spherical lens positioned on the optical axis between said slit aperture and said optical sensor means, for imagining said slit aperture at a second plane on the distal side of said spherical lens, a second light-trap positioned on the optical axis at said second plane for absorbing tertiary lightbeams produced by dust and the like, and traversing said slit aperture.
Claim 3
Dependent Claim
249 words
The combination comprising: a mask with light-transmitting elongated slit aperture, means for producing a lightbeam directed towards said mask along an optical axis, first and second crossed cylindrical lenses positioned on the proximal side of said slit aperture and on the optical axis, for converging said lightbeam in a first direction transverse to the direction of propagation of said lightbeam so that the lightbeam is focused substantially to a line on said slit aperture, and for converging said lightbeam in a second transverse direction substantially perpendicular to said first direction so that after passing through said slit aperture the lightbeam is converged at a first plane spaced from and on the distal side of said mask, the lightbeam emerging from said slit aperture being defined as a primary lightbeam, a first light-trap positioned on the optical axis at said first plane for absorbing said primary lightbeam, optical-sensor means, positioned on the optical axis on the distal side of said slit aperture and said first light-trap for producing an output-signal when a particle present in said primary lightbeam located between said mask and said first light-trap produces secondary lightbeams, a spherical lens positioned on the optical axis between said slit aperture and said optical sensor means, for imagining said slit aperture at a second plane on the distal side of said spherical lens, a second light-trap positioned on the optical axis at said second plane for absorbing tertiary lightbeams produced by dust and the like, and traversing said slit aperture.
Claim 4
Dependent Claim
249 words
The combination comprising: a mask with light-transmitting elongated slit aperture, means for producing a lightbeam directed towards said mask along an optical axis, first and second crossed cylindrical lenses positioned on the proximal side of said slit aperture and on the optical axis, for converging said lightbeam in a first direction transverse to the direction of propagation of said lightbeam so that the lightbeam is focused substantially to a line on said slit aperture, and for converging said lightbeam in a second transverse direction substantially perpendicular to said first direction so that after passing through said slit aperture the lightbeam is converged at a first plane spaced from and on the distal side of said mask, the lightbeam emerging from said slit aperture being defined as a primary lightbeam, a first light-trap positioned on the optical axis at said first plane for absorbing said primary lightbeam, optical-sensor means, positioned on the optical axis on the distal side of said slit aperture and said first light-trap for producing an output-signal when a particle present in said primary lightbeam located between said mask and said first light-trap produces secondary lightbeams, a spherical lens positioned on the optical axis between said slit aperture and said optical sensor means, for imagining said slit aperture at a second plane on the distal side of said spherical lens, a second light-trap positioned on the optical axis at said second plane for absorbing tertiary lightbeams produced by dust and the like, and traversing said slit aperture.
Claim 5
Dependent Claim
33 words
The combination of claim 1 wherein said slit aperture has its longitudinal axis substantially parallel to the longitudinal axis of one of said cylindrical lenses, whereby said primary lightbeam has a rectangular cross-section.
Claim 6
Dependent Claim
17 words
The combination of claim 2 wherein said first light-trap is rectangular for absorbing said rectangular primary lightbeam.
Claim 7
Dependent Claim
24 words
The combination of claim 3 wherein said second light-trap is rectangular, and positioned in the image-plane corresponding to the object-plane established by said slit.
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |