Abstract: A shank of a diamond scriber suitable for substantially flat-surfaced materials that is to be scribed with particularly high loads. The shank includes a blind hole for retaining a diamond single crystal. The blind hole includes a rectangular mouth and four triangular sidewalls, each of which includes one edge of the rectangular mouth and meets the other three.

Abstract: This is a diamond scriber in which the apex region of a triangular pyramid, which is a toe and/or heel of a diamond particle, is formed to a knife-edge shape that follows a ridge line connecting the toe and heel. In this way, an edge of the diamond scriber is formed to a knife-edge shape, and so it is possible to limit the spread of the slot width in the wafer, and it is possible to maintain a good quality scribe line for a longer period. Further, it is possible to prolong the lifetime of the diamond scriber.

Abstract: A speaker device which comprises a diaphragm made of synthetic resin. The diaphragm is formed by injection molding and is plated with metal on both surfaces thereof for enhancing the rigidity against bending. The diaphragm is capable of vibrating as a whole, without making a wavy movement in the axial direction as if the entirety were a rigid matter, with a result of producing a loud and clear sound without any distortion or strain.

Abstract: A movable coil type electroacoustic vibrating plate of rigid structure, composed of two principal parts, one being a thin-walled annular plate portion, having concentrical outer periphery and inner periphery, of substantially truncated conical configuration, and the other being a thin-walled circular dome-like plate portion for occupying the central circular portion of the former inside the inner periphery. The former is provided with a number of radial ribs on the inner surface thereof with an equal circumferential angular distance, and the latter is also provided with a plurality of diametrical ribs of half-moon shape on the concaved inner surface thereof with an equal circumferential angular distance. The former and the latter are integrally formed mostly and connected with the axial end portion of the bobbin provided with the voice coil.

Abstract: A dynamic speaker including a cone, which is of relatively thin rigid truncated cone shape, having a number of radial ribs extending from the central opening portion toward the peripheral portion thereof, and being progressively diminishing, in respect of the stiffness at the concentrical sections, from the central opening portion toward the peripheral portion thereof, with the object of getting excellent sound effects, a high output power and other merits. Methods of manufacturing the dynamic speaker are also included in this invention.