Patent US3764487A successfully refreshed from Google Patents.
Patent US3799679A successfully refreshed from Google Patents.
US3799679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass distortion scanning system
Assignee: PPG Industries Inc
•
Filing: 1972-06-27
•
Granted: 1974-03-26
•
Expires: 1992-06-27
Abstract
Abstract Disclosed are a method and apparatus for detecting distortion in glass, particularly glass ribbons, by scanning the glass with a light beam and photoelectrically measuring the rate of change of the widthwise, center-to-center spacing betweeen a reflected image of said beam from one surface of the glass and a reflected image of said beam from the opposite surface of the glass. The center-to-center spacing of the reflected beams varies as the distortion in the glass varies, and the rate of change of the spacing is a measure of the refractive power or distortion in the glass.
Inventors
- 👤 G Simko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:34
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/892; G01N21/896
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
Apparatus for measuring refractive power of glass, comprising: means for transmitting a beam of light of finite width at an oblique angle onto a first surface of two opposite surfaces of the glass, the beam of light being refracted through the first surface to the second surface to reflect a reflected image from the first surface and a refracted image from the second surface; means for measuring the rate of change of the widthwise, center to center spacing between the reflected image and the refracted image reflected from the glass, said measuring means including a photosensitive element means positioned in the path of the reflected image and the refracted image produced by the beam and a differentiation circuit connected to the output from said photosensitive element; and means for transporting said light transmitting means and said photosensitive element means along a scan path across the width of the glass.
Claim 2
Dependent Claim
149 words
Apparatus for measuring refractive power of glass, comprising: means for transmitting a beam of light of finite width at an oblique angle onto a first surface of two opposite surfaces of the glass, the beam of light being refracted through the first surface to the second surface to reflect a reflected image from the first surface and a refracted image from the second surface; means for measuring the rate of change of the widthwise, center to center spacing between the reflected image and the refracted image reflected from the glass, said measuring means including a photosensitive element means positioned in the path of the reflected image and the refracted image produced by the beam and a differentiation circuit connected to the output from said photosensitive element; and means for transporting said light transmitting means and said photosensitive element means along a scan path across the width of the glass.
Claim 3
Dependent Claim
14 words
Apparatus according to claim 1 wherein said photosensitive element means comprises a scanning photomultiplier.
Claim 4
Dependent Claim
24 words
Apparatus according to claim 1 wherein the path of the reflected image is at a small angle to the path of the refracted image.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 2 wherein the reflected image partially overlaps the refracted image in the field of view of said scanning photomultiplier.
Claim 6
Dependent Claim
32 words
Apparatus according to claim 1 which further includes a strip-chart recorder connected to an output signal from said differentiation circuit for recording said rate of change of said spacing of said images.
Claim 7
Dependent Claim
36 words
Apparatus according to claim 1 which further includes a rectifier circuit connected to an output signal from said differentiation circuit for determining the absolute value of said rate of change of said spacing of said images.
Claim 8
Dependent Claim
36 words
Apparatus according to claim 6 which further includes a discriminator circuit connected to said output signal from said rectifier circuit for determining the peak value of said rate of change of said spacing of said images.
Claim 9
Dependent Claim
27 words
Apparatus according to claim 7 wherein said discriminator circuit determines peak value for a plurality of zones along said scan path across the width of said glass.
Claim 10
Dependent Claim
36 words
Apparatus according to claim 6 which further includes an integrator circuit connected to said output signal from said rectifier circuit for determining the sum value of said rate of change of said spacing of said images.
Claim 11
Dependent Claim
27 words
Apparatus according to claim 9 wherein said integrator circuit determines sum values for a pluraliTy of zones along said scan path across the width of said glass.
Claim 12
Dependent Claim
62 words
Apparatus according to claim 6 which further includes a a discriminator circuit and an integrator circuit, each connected to said output signal from said rectifier circuit for determining, respectively, the peak values and the sum values of said rate of change of said spacing of said images for a plurality of zones along said scan path across the width of said glass.
Claim 13
Dependent Claim
27 words
Apparatus according to claim 11 which further includes a computer connected to an output signal from said discriminator curcuit and an output signal from said integrator circuit.
Claim 14
Dependent Claim
27 words
Apparatus according to claim 12 which further includes process control equipment connected to said computer for changing process parameters in response to a signal from said computer.
Claim 15
Dependent Claim
30 words
Apparatus according to claim 12 which further includes glass marking equipment connected to said computer for marking distortion defects in said glass in response to a signal from said computer.
Claim 16
Dependent Claim
27 words
Apparatus according to claim 12 which further includes glass cutting equipment connected to said computer for cutting said glass in response to a signal from said computer.
Claim 17
Independent Claim
111 words
A method of measuring refractive power of glass, comprising the steps of: transmitting a beam of light of finite width at an oblique angle onto a first surface of two opposite surfaces of the glass, the beam of light being refracted through the glass to a second surface to reflect a reflected image from the first surface and a refracted image from the second surface; imparting relative motion between the glass and the beam of light in a direction crosswise of the width of the glass; and contemporaneously measuring the rate of change of the widthwise, center to center spacing of the reflected image the refracted image reflected from the glass.
Claim 18
Independent Claim
111 words
A method of measuring refractive power of glass, comprising the steps of: transmitting a beam of light of finite width at an oblique angle onto a first surface of two opposite surfaces of the glass, the beam of light being refracted through the glass to a second surface to reflect a reflected image from the first surface and a refracted image from the second surface; imparting relative motion between the glass and the beam of light in a direction crosswise of the width of the glass; and contemporaneously measuring the rate of change of the widthwise, center to center spacing of the reflected image the refracted image reflected from the glass.
Claim 19
Dependent Claim
34 words
A method according to claim 16 which further includes the step of: transmitting a signal proportionate to the measured values of said rate of change of said spacing of said images to a computer.
Claim 20
Dependent Claim
39 words
A method according to claim 17 which further includes the step of: transmitting a signal from said computer to process control equipment for changing process parameters in response to said rate of change of said spacing of said images.
Claim 21
Dependent Claim
42 words
A method according to claim 17 which further includes the step of: transmitting a signal from said computer to glass marking equipment for marking distortion defects in said glass in response to said rate of change of said spacing of said images.
Claim 22
Dependent Claim
39 words
A method according to claim 17 which further includes the step of: transmitting a signal from said computer to glass cutting equipment for cutting said glass in response to said rate of change of said spacing of said images.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |