Patent attributes
A manufacturing method of a resin frame includes preparing a plurality of frame members, installing a pair of the frame members in the corner portion in a pair of molds, melting end surfaces of the pair of the frame members as welding margins, and welding the welding margins. The molds respectively includes a reference surface holding the frame members and a blade portion protruding to an inner side with respect to the reference surface. In the welding, in the corner portion, the pair of the frame members are pressed by the blade portions, so that the welding margin protrudes from between the blade portions, the outer peripheral surfaces of the pair of the frame members are bent inward, and the corner portion is made concave with respect to the portions adjacent to the corner portion.
