Abstract: A spiral phase plate, according to one embodiment, for generating a Laguerre Gaussian beam by reflecting an incident beam emitted from a light source, may comprise: a first quadrant area in which the step height increase rate per unit angle decreases progressively in one direction from the point with the lowest step height to the point with the highest step height; and a second quadrant area in which the step height increase rate per unit angle increases progressively in the one direction.

Abstract: A method of and a device for attaching a speaker to a synthetic resin body having an opening in which the speaker's elevating edge of a cylindrical shape integrally formed at a tip end portion of a metal frame, is confronted with the synthetic resin body so as to surround and close the opening. The elevating edge is heated and the speaker is pushed toward the synthetic resin body side, the synthetic resin body is fused by heating at its location where it contacts the heated elevating edge and the elevating edge is fitted into the synthetic resin body by a pressing force, whereafter the speaker is attached to the synthetic resin body by solidifying the synthetic resin body after the heating has been stopped.

Abstract: A method of and a device for attaching a speaker to a synthetic resin body having an opening in which the speaker's elevating edge of a cylindrical shape integrally formed at a tip end portion of a metal frame, is confronted with the synthetic resin body so as to surround and close the opening. The elevating edge is heated and the speaker is pushed toward the synthetic resin body side, the synthetic resin body is fused by heating at its location where it contacts the heated elevating edge and the elevating edge is fitted into the synthetic resin body by a pressing force, whereafter the speaker is attached to the synthetic resin body by solidifying the synthetic resin body after the heating has been stopped.