US 5,210,592 A · Method and apparatus for determining the optical quality of a transparent plate

Abstract

Method for determining the optical quality of a transparent plate, particularly a float glass plate, in which two parallel light beams having a reciprocal spacing are directed onto the plate under an acute angle, relative to the plate normal, the light beams reflected by the plates are received separately by a detector having a photosensitive detector and the direction of the reflected light beams is evaluated, in which all four light beams A1, A2, B1, B2 reflected by the two surfaces of the plate are received by a position-sensitive detector, the reciprocal spacing and the angle of incidence .epsilon..sub.0 of the incident light beams A, B are so adjusted as a function of the plate thickness that the reflected light beams A1, A2, B1, B2 are detected in a spatially separated manner by the detector and from the impact points of all four reflected light beams A1, A2, B1, B2 on the position-sensitive detector the parameters are calculated for the quantitative determination of the optical quality of the plate, as well as an apparatus for performing the method.

Claims22

Dependent claims

A method of determining the optical quality of a transparent plate, comprising:

directing two parallel incident light beams A, B having a reciprocal spacing onto the plate at an acute angle, relative to the plate normal, said plate having two surfaces for reflecting said two incident light beams A, B to produce reflected beams A1, A2, B1, B2;
adjusting the reciprocal spacing and the angle of incidence .epsilon..sub.0 of the incident light beams A, B as a function of the thickness of the plate such that each of said reflected beams A1, A2, B1, B2 impact detecting means in a spatially separated manner, said detecting means comprising a photosensitive detector, said detector being position-sensitive;
detecting the impact points of each of the reflected light beams A1, A2, B1, B2 on the position-sensitive detector;
evaluating the respective directions in which the reflected light beams A1, A2, B1, B2 have been reflected by the surfaces of the plate from said impact points;
and
calculating, from said respective directions, parameters to quantitatively determine the optical quality of the plate.

3 more elements

An apparatus for determining the optical quality of a transparent plate, comprising:

a laser light source for emitting a light beam;
means for receiving said light beam from said laser light source and for producing therefrom two parallel light beams having a reciprocal spacing;
means for directing said two parallel light beams onto the plate at an acute angle, relative to the plate normal, to become incident light beams A, B, said incident light beams A, B each being reflected by two surfaces of said plate to produce four light beams A1, A2, B1 and B2;
means for receiving said four light beams A1, A2, B1 and B2 and for separately detecting the four reflected light beams, said detecting means comprising a photosensitive detector;
and
means for determining the optical quality of the plate based on signals output from the detecting means according to detection of the four reflected beams,
wherein the detecting means includes a position-sensitive detector (24), and
wherein the determining means (34) for determining quantitative parameters characterizing the optical quality of the plate (26) from impact points of the four light beams A1, A2, B1, B2 is coupled to the position-sensitive detector (24).

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for determining the optical quality of a transparent plate

Life of this patent

Method and apparatus for determining the optical quality of a transparent plate

Life of this patent

Abstract

Claims22