DIAPHRAGM FOR SPEAKER

摘要

PURPOSE:To prevent the change in sound quality due to deterioration in the diaphragm by using a thin film formed by adhering a hard chromium onto a composite of thermosetting resins such as mica and epoxy resin as a surface member of a diaphragm to increase the surface strength. CONSTITUTION:A radial core member is formed by folding an aluminum ribbon 1 having a thickness of nearly 20mum at the center and the outer circumference of a circle at first, and a skin member 2 is bonded to both the sides. This skin member 2 is formed by a composite thin film 3 made of a composite material of mica and epoxy resin and a chromium layer 4 adhered to the surface of the comosite thin film 3 and bonded to the upper face and the lower face of the core member 1 by an adhesives 5. The composite thin film 3 is formed by forming the flaky mica of nearly 100 mesh into a sheet form by means of the paper- making method, impregnating 20-30% epoxy resin to the sheet and heating and pressing the sheet to cure the impregnated sheet. The chromium layer 4 is formed by adhering chromium by means of the vacuum-deposition method.