| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform noncontact charging of a battery of electronic equipment, while reducing the number of components by using the voice coil of a speaker as a secondary coil. <P>SOLUTION: When a digital camera 10 is placed on a wireless charging stand 20, a charge control unit 23 drives the charging primary coil 22 provided to the wireless charging stand 20, causing the primary coil 22 to generate a variable magnet field which varies with a predetermined period within an audio frequency range. During charging, a slide cover 14 is located in a closed position, the magnetic element 132 of the speaker 13 provided to the digital camera 10 is arranged, at a charging position shifted in parallel from a normal position covering the back side of the magnetic element 131. Then, in the voice coil 134 of the speaker 13 an induced electromotive force is produced by the varying magnet field, so that the charging circuit of the digital camera 10 charges the battery using the induced electromotive force generated in the voice coil 134. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
