Patent ID: 7418532

Claim:
A data transfer device performing data transfer with another device, comprising: a transfer rate detector for detecting an effective data transfer rate based on an actual data transfer performed between the data transfer device and the another device; and a transfer rate controller for controlling a data transfer rate in a stepwise manner according to the result of the detection of the effective data transfer rate performed by the transfer rate detector, wherein at predetermined timing, the transfer rate controller selects a data transfer rate that is one step greater than a currently-selected data transfer rate, if the effective data transfer rate that is detected by the transfer rate detector is lower than the original data transfer rate while the data transfer rate that is one step greater is being selected, then the transfer rate controller reverts the data transfer rate to the original data transfer rate, and if the effective data transfer rate detected by the transfer rate detector is greater than the original data transfer rate, then the transfer rate controller maintains the data transfer rate that is one step greater.