Patent ID: 8196440

Claim:
A drum washing machine comprising: a rotating tub comprised of a cylindrical drum having a front formed with a circular opening through which laundry is put into the rotating tub and a rear closed; a DC brushless motor configured to generate a driving force for wash, rinse and dehydration operations and including a rotor; a rotational shaft of the motor having a front end directly fixed to the rotating tub and a rear end fixed to a core of the rotor so that torque developed by the motor is directly transmitted to the rotating tub; a current detector configured to detect electric current flowing into the motor; a torque control unit configured to perform a vector control for the motor on the basis of the current detected by the current detector so that torque developed by the motor is rendered optimum for at least the wash and dehydration operations; a speed control unit configured to control a rotational speed of the motor, based on the current detected by the current detector; and a laundry amount determining unit configured to determine an amount of laundry in the rotating tub, based on a magnitude of an accumulated value of torque current in a period when a rotational speed of the motor is accelerated, wherein an amount of detergent to be necessitated according to the determined amount of laundry is displayed on a display.