U.S. patent application number 10/717637 was filed with the patent office on 2004-06-03 for washing machine and control method thereof.
Invention is credited to Do, Gi Hyeong, Kim, Kweon.
Application Number | 20040103485 10/717637 |
Document ID | / |
Family ID | 32388219 |
Filed Date | 2004-06-03 |
United States Patent
Application |
20040103485 |
Kind Code |
A1 |
Do, Gi Hyeong ; et
al. |
June 3, 2004 |
Washing machine and control method thereof
Abstract
A washing machine and a control method thereof are provided for
accurately sensing an amount of laundry placed in the washing
machine and setting a wash pattern accordingly. The washing machine
includes a motor for being driven, in response to a user command,
to rotate a drum holding laundry; a pulse sensor for sensing a
pulse generated by the driven motor and outputting a voltage signal
indicative of a width of the pulse; and a microcomputer for sensing
an amount of laundry based on an integration value derived from the
voltage signal output from the pulse sensor and on a revolution
time period with respect to a reference value stored in the
microcomputer. The control method includes steps of sensing a
laundry amount according to a pulse generated when a motor is
driven in response to a user command; and controlling a wash
pattern according to the sensed laundry amount.
Inventors: |
Do, Gi Hyeong; (Changwon-si,
KR) ; Kim, Kweon; (Jinhae-si, KR) |
Correspondence
Address: |
Song K. Jung
MCKENNA LONG & ALDRIDGE LLP
1900 K Street, N.W.
Washington
DC
20006
US
|
Family ID: |
32388219 |
Appl. No.: |
10/717637 |
Filed: |
November 21, 2003 |
Current U.S.
Class: |
8/159 ;
68/12.04 |
Current CPC
Class: |
D06F 2103/38 20200201;
D06F 33/36 20200201; D06F 34/18 20200201; D06F 2103/04
20200201 |
Class at
Publication: |
008/159 ;
068/012.04 |
International
Class: |
D06F 033/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2002 |
KR |
P 2002-0073895 |
Claims
What is claimed is:
1. A washing machine comprising: a motor for being driven, in
response to a user command, to rotate a drum holding laundry; a
pulse sensor for sensing a pulse generated by said driven motor and
outputting a voltage signal indicative of a width of the pulse; and
a microcomputer for sensing an amount of laundry based on at least
an integration value derived from the voltage signal output from
said pulse sensor.
2. The washing machine as claimed in claim 1, wherein a value
representing one revolution of said motor is stored in said
microcomputer as a reference.
3. The washing machine as claimed in claim 2, further comprising a
timer for measuring a revolution time period required for said
driven motor to reach a predetermined position of rotation, wherein
the sensing of the laundry amount is further based on the
revolution time period with respect to the reference value stored
in said microcomputer.
4. The washing machine as claimed in claim 3, wherein the
predetermined position of rotation is a 2/5 revolution point.
5. The washing machine as claimed in claim 4, wherein the
revolution time period is measured from a static position of said
motor to the 2/5 revolution point.
6. The washing machine as claimed in claim 1, wherein said motor is
driven according to a wash pattern.
7. The washing machine as claimed in claim 6, wherein the wash
pattern is set based on the sensed laundry amount.
8. A method of controlling a washing machine, the method comprising
steps of: sensing a laundry amount according to a pulse generated
when a motor is driven in response to a user command; and
controlling a wash pattern according to the sensed laundry
amount.
9. The method as claimed in claim 8, said sensing step comprising
steps of: sensing a width of the pulse, the pulse width being
indicative of a rotation of the motor under a load from a static
position to a predetermined position; generating an integration
value derived from the sensed pulse width; and determining the
sensed laundry amount based on at least the generated integration
value.
10. The method as claimed in claim 9, said sensing step further
comprising steps of: setting as a reference a value representing
one revolution of the motor; driving the motor under a load, to
rotate from the static position to the predetermined position of
rotation, and simultaneously initializing a timer in response to
the user command; and measuring a revolution time period required,
after timer initialization, for the motor to reach the
predetermined position of rotation, wherein the determination of
the sensed laundry amount is further based on the revolution time
period with respect to the set reference value.
11. The method as claimed in claim 8, further comprising a step of
setting a wash pattern based on the sensed laundry amount.
Description
[0001] This application claims the benefit of Korean Application
No. 10-2002-0073895 filed on Nov. 26, 2002, which is hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] 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.
[0004] 2. Discussion of the Related Art
[0005] Generally speaking, a washing machine, which may include
pulsator-, stir-, and drum-types, is an apparatus for cleaning
laundry by performing washing, rinsing, and dewatering steps
according to a programmed cycle and a wash pattern appropriate for
a given amount of laundry. At the outset of the washing step, an
amount of laundry is placed in the washing machine, which senses
the amount and supplies water accordingly, taking into
consideration a wash command selected by a user. The supply of
water continues until a predetermined level is reached, whereupon a
motor is driven to begin the washing step and is accelerated to a
predetermined speed. Shortly thereafter, as the laundry begins to
absorb the water, the predetermined level initially drops according
to the degree of absorption. The reduced level is sensed, and
additional water is supplied to compensate for the amount of
absorbed water.
[0006] FIG. 1 illustrates an apparatus for sensing an amount of
laundry in a washing machine according to a related art. The
apparatus includes a microcomputer 2, having an internal timer 2a,
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 1 and outputting a
control signal to a load driver 3; a motor 4, driven by the load
driver, for rotating in accordance with the control signal a drum
(not shown) holding an amount of laundry; and an rpm detection
means 5 for detecting the rotational speed of the motor as a
revolutions per minute (rpm) signal provided to the
microcomputer.
[0007] To sense the amount of laundry in the washing machine
according to a related art, the time required for the motor 4 to
rotate an empty drum and accelerate to the predetermined speed, as
detected by the rpm detection means 5, is taken as a reference. The
acceleration time, as measured by the internal timer 2a of the
microcomputer 2, increases for larger and larger amounts of laundry
and the corresponding levels of water. The laundry amount (load) is
sensed using this principle, and the wash pattern is determined
accordingly.
[0008] In the above method for sensing an amount of laundry in a
washing machine according to the related art, however, in which an
amount of additional water is supplied as the laundry absorbs the
initially supplied water, the sensing of the amount of laundry is
inconsistent, and therefore inaccurate, since various types of
laundry exhibit varying rates and degrees of water absorption. That
is, the laundry amount sensing apparatus of the related art cannot
respond to the change in water level. As a result, the wash pattern
is determined improperly, which degrades the washing performance of
a washing machine.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is directed to a washing
machine and control method thereof that substantially obviates one
or more of the problems due to limitations and disadvantages of the
related art.
[0010] An object of the present invention, which has been devised
to solve the foregoing problem, lies in providing a washing machine
and control method thereof, in which a laundry amount is accurately
sensed by calculating a revolution time and a corresponding pulse
width generated during the time required for the motor to rotate
from a static position to a predetermined position.
[0011] It is another object of the present invention to provide a
washing machine and control method thereof, in which a wash pattern
is properly set for any amount or type of laundry in the washing
machine.
[0012] Additional features and advantages of the invention will be
set forth in the description which follows, and in part will be
apparent to those having ordinary skill in the art upon examination
of the following or may be learned from a practice of the
invention. The objectives and other advantages of the invention
will be realized and attained by the subject matter particularly
pointed out in the specification and claims hereof as well as in
the appended drawings.
[0013] To achieve these objects and other advantages in accordance
with the present invention, as embodied and broadly described
herein, there is provided a washing machine comprising a motor for
being driven, in response to a user command, to rotate a drum
holding laundry; a pulse sensor for sensing a pulse generated by
the driven motor and outputting a voltage signal indicative of a
width of the pulse; and a microcomputer for sensing an amount of
laundry based on at least an integration value derived from the
voltage signal output from the pulse sensor. A value representing
one revolution of the motor is stored in the microcomputer as a
reference, and a timer is provided in the microcomputer for
measuring a revolution time period required for the driven motor to
reach a predetermined position of rotation, wherein the sensing of
the laundry amount is further based on the revolution time period
with respect to the reference value stored in the microcomputer.
The motor is driven according to a wash pattern, which is set based
on the sensed laundry amount.
[0014] In another aspect of the present invention, there is
provided a method of controlling a washing machine. The method
comprises steps of sensing a laundry amount according to a pulse
generated when a motor is driven in response to a user command; and
controlling a wash pattern according to the sensed laundry
amount.
[0015] It is to be understood that both the foregoing explanation
and the following detailed description of the present invention are
exemplary and illustrative and are intended to provide further
explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] 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:
[0017] FIG. 1 is a block diagram of an apparatus for sensing an
amount of laundry in a washing machine according to a related
art;
[0018] 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
[0019] FIG. 3 is a flowchart of a method for sensing an amount of
laundry in a washing machine according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] 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.
[0021] 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.
[0022] 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.
[0023] Referring to FIG. 3, illustrating a method for sensing an
amount of laundry in a washing machine according to the present
invention, once a wash execution command is input via the key input
unit 10, the microcomputer 20, in a step S31, outputs the control
signal to the load driver 30 to begin driving the motor 40 and
simultaneously initializes the internal timer 20a. Subsequently, it
is determined in a step S32 whether the motor 40 has rotated to the
predetermined position. Here, the microcomputer 20 references the
stored value representing one revolution of the motor 40 and
determines that the motor has rotated to the predetermined position
if the voltage signal output from the pulse sensor 60 corresponds
to two-fifths of the stored value.
[0024] It should be appreciated that the pulse width generated by
the revolution of the motor 40 increases during a step S33 until
the predetermined position is reached. Thus, the voltage signal
output from the pulse senor 60 is integrated over time, producing
an integration value for use by the microcomputer 20.
[0025] In a step S34, the revolution time and integration value are
calculated at the 2/5 revolution point, and a sensed amount of
laundry is determined based on the calculation. In a step S35, a
wash pattern is set based on the sensed laundry amount.
[0026] It is important to note that, just prior to the execution of
a wash command as described above, the washing machine of the
present invention is in a static state. That is, the motor 40 is
not being driven and the laundry is gathered in the bottom of the
drum. Furthermore, it can be assumed the integration value, based
on the sensed pulse width input and voltage signal output of the
pulse sensor 60, increases uniformly per unit time. Therefore, a
load force and the resulting revolution time are directly
proportional to the amount of laundry, enabling an accurate
determination of the laundry amount. Namely, as the load force
increases in proportion to the laundry amount, so does the
integration value resulting from the increased pulse width due to
the longer time taken for reaching the predetermined position (the
2/5 revolution point).
[0027] As described above, the washing machine according to the
present invention employs a pulse sensor coupled to a motor driven
to rotate a drum holding an amount of laundry, to measure a pulse
width generated by the driven motor, in order to sense the laundry
amount accurately. The laundry amount is sensed by calculating a
revolution time, based on the time required for the motor to travel
from a static position to a 2/5 revolution point, and a
corresponding integration value determined by a voltage signal
output from the pulse sensor. Thus, the wash pattern can be
properly set regardless of any change in water level due to an
absorption of initially supplied water by the laundry.
[0028] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover such modifications
and variations, provided they come within the scope of the appended
claims and their equivalents.
* * * * *