| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reliably communicate with a host apparatus with a simple configuration. <P>SOLUTION: A terminal apparatus as an Sp (Self-powered) device requests power of 500 mA by notifying the host apparatus 5 that the terminal device 1 is a Bp (Bus-powered) device. When the power can be obtained, the terminal device 1 operates only by the power, thereby minimizing power consumption of a battery 2. When only power of 100 mA or less can be obtained from the host apparatus immediately after power-ON or the like, the terminal device 1 operates by power obtained from the battery 2. Thus, electric power shortage during the communication with the host apparatus can be avoided with the simple configuration. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
