Company is China's optical disc industry is currently one of the most strength and development potential of the company, set product design, research and development, production, sales as one. After many years of healthy and steady development, with the world's advanced technology can record the disc production line 42 (108 head), the company's products by domestic and foreign customers of all ages and praise, in particular, self brand has grown into China's optical disc industry leader brand. Magnetoelectric sensor has two basic components: A is constant DC magnetic field of the magnetic circuit system, in order to decrease sensor volume. In general, the permanent magnet; another is coil, by it and magnetic flux linkage produces induced electromotive force. The induced electromotive force is proportional to the magnetic flux change rate or the relative velocity between the coil and the magnetic field, so there must be a relative movement between them. As a moving part, it can be a coil, or a permanent magnet. Therefore, it is necessary to choose the structure form, material and structure size of the sensor to meet the basic performance requirements of the sensor.