Invisible edge solid substrate compensation layer for automotive glazing

Abstract

Vehicle glazing, which once served just to provide for vision and protect from the elements, has been taking on new functions as the complexity and functionality of modern automobiles has evolved. Performance films and interlayers are often used to add to and enhance the functionality of laminates. These functions include solar control, sound dampening, head up display and variable light transmittance. Recent advances have made it possible to produce electronic circuits on thin transparent substrates that are essentially invisible under normal lighting conditions. While these circuits can be inserted into the laminate and successfully laminated, the edges of the circuit insert are prone to objectionable aesthetics due to mismatch between the substrate and the interlayer index of refraction, thickness and color. The present invention compensates the edge of the solid insert by providing a sheet of a compatible compensation material that the substrate of the insert and which extends to at least the black band or the edge of glass of the laminate making the insert edge essentially invisible.