Abstract: An apparatus and method for inspecting pieces of glass and other transparent sheets for optical defects is provided. The inspection apparatus can be integrated directly into the production line. The inspection apparatus includes an electro-optic inspection of the total viewing area for each transparent sheet as the sheets are conveyed at the end of the production operation. The apparatus includes a plurality of laser light sources positioned on one side of the sheet of glass or other transparent material, and a corresponding plurality of lenses and photosensitive position detectors on the opposite side. Light beams are directed from the light sources through the transparent sheets to the lenses and the detectors. The angular deviation of each light beam which occurs as the light beam passes through the sheet generates a signal at each of the detectors.

Abstract: A heated window assembly for a vehicle includes a pair of spaced apart bus bars connected by a conductive film. A sense line is connected to one of the bus bars to monitor and compare the voltage applied to the bus bar. A control circuit connected to the sense line detects a difference in voltage in the bus bar as compared to a reference voltage and disconnects the bus bars from the vehicle power supply.

Abstract: An apparatus for determining and displaying selected characteristics of a film formed on the surface of a glass ribbon includes a scanning head mounted on a track for movement above the filmed surface of the glass ribbon. The scanning head has a source of light pulses generated from a tungsten lamp and chopper, filtered to simulate daylight and focused on the filmed surface. An integrating sphere is also mounted on the scanning head and has an entrance port formed in a wall thereof for collecting a portion of the light being reflected from the surface. Optically filtered detectors mounted in detector ports formed in the wall of the sphere generate output signals representing the "Y" and "Z" components of the collected light on the CIE X,Y,Z, tristimulus scale.

Abstract: An apparatus for synchronizing the movement of glass sheets through a furnace includes a stop for holding the sheets at the entrance to the furnace. An actuator is responsive to a synchronizing signal for moving the stop and releasing the sheet into the furnace. A reference point sensor detects a reference point associated with a rotating conveyor roller adjacent the entrance to the furnace when the reference point is in a predetermined spatial relationship to the glass sheet which is being held at the entrance. Thus, each glass sheet enters the furnace and engages the conveyor rollers in the same position such that any roller corrugation pattern is reproduced in the same position on each glass sheet. When two such glass sheets are laminated together to form a windshield, the roller corrugation patterns can be matched to reduce the optical distortion produced by the corrugation.

Abstract: The present invention relates to an inspection apparatus for detecting the surface distortion in a sheet of material such as a sheet of glass, for example, and for indicating whether the level of distortion detected in the inspected sheet is unacceptable. The inspection apparatus includes a light source mounted to direct a first beam of light toward one surface of the sheet at an oblique angle of incidence to cause a second beam of light to be reflected therefrom. A light detector is mounted to receive the reflected beam and is responsive to a light pattern produced by the reflected beam of light for generating an output signal representing the width of the light pattern. The width of the light pattern is a function of the surface distortion of the portion of the surface from which the beam is reflected. A control circuit is responsive to the detector output signals for generating an actual distortion signal representing the amount of surface distortion in the inspected portion of the surface.

Abstract: An alignment system having a light source for projecting a reference light beam extending longitudinally with and parallel to the centerline of a roller conveyor for establishing a common reference plane containing the axes of a plurality of transversely extending conveyor rolls. Preferably, the light beam is spaced within a specified distance from the ends of the conveyor rolls. The system includes a laser having a beam expander for reducing the divergence of the light beam over long distances, a penta prism for bending the incident light beam at right angles from its projected path and directing the bent light beam against a mirror attached to an end of one of the conveyor rolls. The mirror reflects the beam back to the penta prism which, in turn, directs the reflected beam against a target located at the light source whereat the reflection of the light beam on the target is used for accurately determining the alignment relationship of that particular conveyor roll to the incident light beam.

Abstract: An inspection system for detecting the flatness of planar glass sheets or other materials having reflective surfaces by observing areas of preselected size on the surfaces. The system includes a collimated beam of light directed toward the surface of the sheet material wherein the collimated beam is split into two pairs of beams superimposed one upon the other at right angles for indicating contour in two directions along perpendicularly oriented axes of the observed area. The indication of flatness is obtained by presetting the spacing between the beams of each pair of beams directed against sheet material and noting any change in the spacing occurring between the reflected beams of each pair of beams. A light beam detector, positioned in the path of each of the pair of reflected beams so as to intercept the reflected beams, detects any change in spacing occurring between the beams of each pair of reflected beams and generates a series of signals in response thereto.