Abstract: A device for inspecting a foil-type transparent object. The device has a camera and at least one light source. The light source is arranged such that the electromagnetic radiation emitted by the light source illuminates a line-shaped area of a first surface of the object from above or a second surface of the object from below. The illumination is at a predetermined angle (?) to the respective illuminated surface. The camera is arranged to detect the intensity of the back-reflected electromagnetic radiation in at least a portion of the line-shaped area. The predetermined angle (?) is less than or equal to 15° and the electromagnetic radiation emitted by the light source (20) is predominantly linear and s-polarized. Also a method of inspection.

Abstract: The method for detecting faults in transparent material includes irradiating a definite partial volume in the material with a first radiation source and coupling light into the material from a second source so that its optical path in the partial volume extends in the interior of the material. A fault in the partial volume is detected by light scattering, bright field absorption, and/or deflection of light of the first radiation source by the fault. The apparatus for detecting faults includes a first radiation source for illuminating a definite partial volume of the material, a detector for detecting light from this partial volume, and a second radiation source. The second radiation source is arranged in relation to the material so that the associated optical path in the partial volume passes exclusively in the interior of the material.

Abstract: The method for detecting faults in transparent material includes irradiating a definite partial volume in the material with a first radiation source and coupling light into the material from a second source. The light is coupled into the material from the second source so that its optical path in the partial volume extends in the interior of the material. The presence of a fault in the partial volume is ascertained by light scattering, bright field absorption and/or deflection of light of the first radiation source by the fault. The apparatus for detecting faults in the material includes a first radiation source for illuminating a definite partial volume, a detector for detecting light originating from this partial volume and a second radiation source. The second radiation source is arranged in relation to the material so that the associated optical path in the partial volume passes exclusively in the interior of the material.

Abstract: The invention relates to a method of determining the optical quality of and detecting faults in flat glass (2) and other transparent materials, especially in float glass, wherein a video camera (1) is arranged to monitor an illuminating device (3) either through the glass (2) or by observing the reflection thereof, the focus being on the glass (2) and the sheet, respectively, and the video camera (1) generates signals in dependence on the quality of the glass (2) and these signals are evaluated, wherein use is made of at least one illuminating device (3), comprising a pattern (4) of adjacent partial portions (5a,5b) alternately different at least in color and/or in intensity, an observation spot of the video camera (1) picks up the pattern (4), two video signals U1,U2 are assigned to the signal of the pattern (4), and a change of the intensity of the video signals U1,U2 is used for evaluating the quality of the glass (2) and the sheet, respectively.

Abstract: The invention relates to a method of determining the optical quality of and for detecting faults in flat glass, especially float glass, or other optically transparent materials, a video camera (1) being arranged to monitor an illuminating device (3) either through a glass (2) or by observing the reflection thereof on the glass or material, the focus being on the glass (2) and the material, respectively, and the video camera (1) generating signals in dependence on the quality of the glass (2), with these signals being evaluated, wherein an illuminating device (3) is used whose color and/or intensity is changed in a defined manner, the observation spot (6) of the video camera (1) in the faultless condition of the glass (2) is located substantially in the middle of the illuminating device (3), the illuminating device (3) has assigned thereto two video signals U1,U2, and a change of intensity of the video signals U1,U2 is used for evaluating the quality of the glass (2).