Washing machine and control method thereof

#This application claims the benefit of Korean Application No. 10-2002-0073895 filed on Nov. 26, 2002, which is hereby incorporated by reference.

#1. Field of the Invention

#The present invention relates to a washing machine, and more particularly, to a method and apparatus for sensing an amount of laundry in a washing machine employing a pulse sensor coupled to a motor.

#The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

#FIG. 1 is a block diagram of an apparatus for sensing an amount of laundry in a washing machine according to a related art;

#FIG. 2 is a block diagram of an apparatus for sensing an amount of laundry in a washing machine according to the present invention; and

#Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Throughout the drawings, like elements are indicated using the same or similar reference designations where possible.

#FIG. 2 illustrates an apparatus for sensing an amount of laundry in a washing machine according to a related art. The apparatus includes a microcomputer 20, having an internal timer 20a, for controlling the overall washing machine system and specifically for determining a wash pattern in accordance with a laundry amount and a user command input via a key input unit 10 and outputting a control signal to a load driver 30; a motor 40, driven by the load driver, for rotating in accordance with the control signal a drum (not shown) holding an amount of laundry; and a pulse sensor 60 for sensing a pulse generated from one revolution of the motor and outputting to the microcomputer a voltage signal indicative of the pulse width. A value representing one revolution of the motor 40 is stored in the microcomputer 20.

#Upon input of a wash execution command from the key input unit 10, the microcomputer 20 outputs the control signal to the load driver 30 to drive the motor 40, and a voltage signal is output based on a count of pulses (pulse width) sensed from the motor thus driven. The output voltage signal is used to determine whether the motor 40 has rotated to a predetermined position, e.g., a 2/5 revolution point, from which a revolution time is determined. The revolution time is measured by the internal timer 20a of the microcomputer 20 and is based on the time that the motor 40 required to rotate from a rotational starting point, i.e., a static position, to the 2/5 revolution point. The microcomputer 20 senses the amount of laundry in the rotating drum, based on the revolution time as measured by its internal timer 20a and the voltage signal output from the pulse sensor 60, and the sensed laundry amount is used to determine a wash pattern.