| 摘要 |
<p>PURPOSE:To suppress the generation of noise without connecting a position designating magnetic generator, to detect a position with a high accuracy with simple constitution, and also to detect a position in the height direction, by adopting a difference detecting system as a position detecting method. CONSTITUTION:Plural magnetic substances 11a-11h are arranged in parallel and at a prescribed interval in a position detecting part 10, and the first coil 12 which has been connected in series, and the second coils 13a-13h which are independent, respectively are wound around each magnetic substance 11a-11h, respectively. To the coil 12 of this detecting part 10, an alternating current of a prescribed period is supplied from a driving power source 30, and an inductive voltage which has been induced in the coils 13a-13h is fetched to a position detecting circuit 40. Also, an alternating current is switched and applied to each of the coils 13a-13h from a power source 20, an inductive voltage fo the coil 12 is fetched successively, and a position where these difference voltages become equal to a reference voltage is calculated. In this way, a magnetic field from an input pen 20 which is not connected to the detecting part 10 is detected with a high accuracy by a difference detecting system.</p> |
