US Patent 7637644 Vehicle lamp housing and cover with welding surface structure

A vehicle lamp has a housing and a transparent cover formed of a transparent resin having a flexural modulus of 2000 MPa or more, and joined to the housing by beam welding. The transparent cover has a first surface and a second surface. The second surface faces the housing, and a welding surface is formed along a circumference of the second surface. The welding surface is formed such that the welding surface has a three-dimensional curved surface in a closed-curve form, and such that each continuing surface of the welding surface is formed as a flat surface with respect to a direction of a normal line thereto or as a curved surface having a curvature radius of 30 mm or more with respect to a direction of a normal line thereto.