| 摘要 |
PURPOSE:To improve a signal conversion efficiency and reduce the equivalent mass of the vibration system by arranging ring detection coil for L and R channels in magnetic fields having pyramidical radial magnetic fluxes respectively. CONSTITUTION:Detection coils for L and R channels are arranged in the first and the second magnetic gaps, and induced voltages are taken out from detection coils respectively. That is, a rectangular V-shaped insulating substrate 17 extending to the first and the second magnetic gaps is provided, and cantilever 18 is fitted to the intersection part of rectangular center lines which is the pivot of substrate 17, and a conductive spiral coil is formed in one face, for example, each inside face of V- shaped wing pieces 17a and 17b of the coil substrate by the etching processing, and these coil patterns are placed in the first and the second magnetic gaps as detection coil 19a for L channel and detection coil 19b for R channel, and induced voltages are obtained from detection coils 19a and 19b according to signal of L and R channels at a record disc trace time. |
