COMPOSITE ACOUSTIC DIAPHRAGM

摘要

PURPOSE:To obtain an acoustic diaphragm for audio apparatus which has a high speed of sound and high internal loss, by collecting one or more kinds of flake-type materials in an array into a direction. CONSTITUTION:The beryllium flakes are arrayed on an aluminum foil, and then an aluminum foil is put on the beryllium flakes. This action is repeated until a prescribed thickness is obtained. This lamination is held by an aluminum die and heated up to a temperature in a range of 650-800 deg.C to be pressed at a time by a pressure in a range of 100-200kg/cm<2>. By this heating, the aluminum flows around the beryllium flakes to secure a connection between the beryllium and aluminum or in the aluminum itself. Thus a diaphragm is obtained. This diaphragm is cut into a diameter of 6cm and then adhered to an aluminum foil honeycomb structure to obtain a flat-plate speaker. In such method, the divided vibration can be suppressed by a high speed of sound along with a high internal loss. Thus a flat frequency characteristic can be obtained.