Patent Description:
Generally, a laundry treatment apparatus is a generic term for an apparatus that washes laundry (i.e. objects to be washed or objects to be dried), an apparatus that dries laundry, and an apparatus that may perform both washing and drying of laundry.

Conventional laundry treatment apparatuses are classified into front loading type laundry treatment apparatuses configured such that laundry is introduced through an introduction opening formed in the front surface of the apparatus, and top loading type laundry treatment apparatuses configured such that laundry is introduced through an introduction opening formed in the upper surface of the apparatus.

A top loading type laundry treatment apparatus may include a cabinet, a tub provided inside the cabinet and having an introduction opening in the upper surface thereof, a drum rotatably provided inside the tub, and a door for opening and closing the introduction opening.

Meanwhile, some conventional top loading type laundry treatment apparatuses are configured in such a manner that the tub is provided in a drawer, which is configured so as to be discharged from the cabinet. These conventional laundry treatment apparatuses have a risk of wash water received inside the tub or laundry inside the drum being discharged when the door is opened in the state in which the drawer is located inside the cabinet.

In addition, the conventional laundry treatment apparatuses have no function of notifying a user of the open state of the door when the door is opened in the state in which the drawer is located inside the cabinet, thus causing the user to leave the door in an open state.

That is, the user cannot check such an open state, and the door may prevent the drawer from being discharged to the outside of the cabinet.

In addition, the conventional laundry treatment apparatuses have no ability to assuredly check whether or not the door is opened in the state in which the drawer is located inside the cabinet. <CIT> relates to a washing machine with a door opening/closing sensing unit including a door for opening or closing a clothing injecting hole, at least more than one piezo-electric elements operating by the opening or closing of the door and an output part for outputting electric signals generated by the piezo-electric elements, wherein a microprocessor is further provided between the piezo-electric elements and the output part for outputting control signals according to voltage signals generated from the piezo-electric elements. <CIT> relates to a removable storage container that may be stored inside an appliance when the appliance is not in use or when the appliance is operated in a freshening mode, a laundry appliance that incorporates such storage container, and a method for freshening the clothes and/or other articles. <CIT> relates to a washing machine, and more particularly, to use a rotary washing machine in which a washing tub (or rotating tub) is installed in a built-in form in a place where it is difficult to use the upper space of the washing machine, such as a kitchen.

Accordingly, the present invention is directed to a laundry treatment apparatus that substantially obviates one or more in problems due to limitations and disadvantages of the related art.

One object of the present invention is to provide a laundry treatment reducing the risk of wash water received inside the tub or laundry inside the drum being discharged when the door is opened in the state in which the drawer is located inside the cabinet.

In addition, another object of the present invention is to provide a laundry treatment apparatus, which may allow a drawer to be discharged from a cabinet even if a door to open an introduction aperture is opened in the state in which the drawer is inserted into the cabinet.

In addition, another object of the present invention is to provide a laundry treatment apparatus, which may determine whether or not a drawer is inserted into a cabinet and may notify a user of the result of the determination.

In addition, another object of the present invention is to provide a laundry treatment apparatus, which may prevent a door from being incorrectly determined to be opened due to, for example, external signals, such as vibration.

In addition, another object of the present invention is to provide a laundry treatment apparatus, which may accurately sense, using magnetic force, whether or not a door to open an introduction opening has been opened.

In addition, a further object of the present invention is to provide a laundry treatment apparatus, which may accurately determine the occurrence of abnormalities in constituent elements for determining whether or not a door to open an introduction opening is opened.

These objects are achieved with the features of the claims.

Additional advantages, objects, and features will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice. The objectives and other advantages may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, in accordance with an aspect of the present invention, a laundry treatment apparatus includes a cabinet having an introduction/discharge opening, a drawer configured so as to be discharged from the cabinet through the introduction/discharge opening, a through-hole formed in an upper surface of the drawer, a tub provided inside the drawer for providing a space for storage of water, an introduction aperture formed in an upper surface of the tub, the introduction aperture being located under the through-hole, a drum rotatably provided inside the tub for receiving laundry supplied to the introduction aperture, a door for opening and closing the introduction aperture, and a door sensing unit for determining whether or not the door to open the introduction aperture is opened in a state in which the drawer is inserted into the cabinet.

The door sensing unit includes a first magnetic-force generator provided in any one of the cabinet and the door for generating magnetic force, and a first magnetic-force sensor provided in a remaining one of the cabinet and the door for sensing the magnetic force provided by the first magnetic-force generator.

The door sensing unit may include a base fixed inside the cabinet so as to be located above the door, a first magnetic-force sensor provided in the base for sensing magnetic force, a body rotatably provided in the base so as to be rotated toward the first magnetic-force sensor when the door to open the introduction aperture is opened, and a first magnetic-force generator fixed to the body.

The laundry treatment apparatus may further include a display unit for notifying a user that the door to open the introduction aperture is opened when the magnetic force sensed by the first magnetic-force sensor is a predetermined first reference magnetic force or more.

The laundry treatment apparatus may further include a display unit for notifying a user that the door to open the introduction aperture is opened when a state in which the magnetic force measured by the first magnetic-force sensor is a predetermined first reference magnetic force or more is continued during a predetermined reference time or more.

The door sensing unit may include a base fixed inside the cabinet so as to be located above the door, a first magnetic-force sensor provided in the base for sensing magnetic force, a body rotatably provided in the base so as to be rotated away from the first magnetic-force sensor when the door to open the introduction aperture is opened, and a first magnetic-force generator fixed to the body.

The laundry treatment apparatus may further include a display unit for notifying a user that the door to open the introduction aperture is opened when the magnetic force sensed by the first magnetic-force sensor is below a predetermined first reference magnetic force.

The display unit may notify a user that the door to open the introduction aperture is opened when a state in which the magnetic force sensed by the first magnetic-force sensor is below the predetermined first reference magnetic force is continued during a predetermined reference time or more.

The display unit may be at least one selected from among a device for displaying characters or symbols, a device for generating sound, and a device for emitting light.

The laundry treatment apparatus may further include a body support portion provided on the base for preventing the body from being rotated toward the door.

The laundry treatment apparatus may further include a body contact portion provided on the body so as to come into contact with the door when the door to open the introduction aperture is opened.

The laundry treatment apparatus may further include a drawer sensing unit for determining whether or not the drawer is inserted into the cabinet to thereby reach a predetermined reference position.

The drawer may include a drawer body provided inside the cabinet for providing a space in which the tub is received, and a drawer panel provided so as to open and close the introduction/discharge opening for discharging the drawer body from the cabinet, and the drawer sensing unit may determine whether or not the introduction/discharge opening is closed by the drawer panel.

The drawer sensing unit may include a second magnetic-force generator provided in any one of the cabinet and the drawer for generating magnetic force, and a second magnetic-force sensor provided in a remaining one of the cabinet and the drawer for sensing the magnetic force provided by the second magnetic-force generator.

The laundry treatment apparatus may further include a display unit for notifying a user that the introduction/discharge opening is in an open state when the magnetic force sensed by the second magnetic-force sensor is below a predetermined second reference magnetic force.

In an aspect, the laundry treatment apparatus is a top loading type laundry treatment apparatuses configured such that laundry is introduced through an introduction opening formed in the upper surface of the apparatus.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention as claimed.

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

Meanwhile, the configuration of an apparatus or a control method of the apparatus, which will be described below, is merely given to describe the embodiments of the present invention, without being intended to limit the scope of the present invention. The same reference numerals used throughout the specification refer to the same constituent elements.

As illustrated in <FIG> and <FIG>, a laundry treatment apparatus of the present invention, designated by reference numeral <NUM>, includes a cabinet <NUM>, a drawer <NUM> provided so as to be discharged from the cabinet <NUM>, a tub <NUM> provided inside the drawer <NUM> for storing water therein, and a drum <NUM> rotatably provided inside the tub <NUM> for storing laundry therein.

The cabinet <NUM> may serve to define the external appearance of the laundry treatment apparatus <NUM>, and may also simply serve as a space in which the drawer <NUM> is received. In any case, the cabinet <NUM> may be provided in the front surface thereof with an introduction/discharge opening <NUM> for the insertion of the drawer <NUM>.

The introduction/discharge opening <NUM> may include an opening <NUM> formed in one surface of the cabinet <NUM>, and a flange <NUM> provided along the edge of the opening <NUM>.

The drawer <NUM> includes a drawer body <NUM> configured so as to be inserted into the cabinet <NUM> through the introduction/discharge opening <NUM>, a drawer panel <NUM> fixed to the front surface of the drawer body <NUM> for opening and closing the opening <NUM>, and a drawer cover <NUM> for forming the upper surface of the drawer body <NUM>.

Because the drawer panel <NUM> is fixed to the front surface of the drawer body <NUM>, the drawer panel <NUM> may serve as a handle for discharging the drawer body <NUM> from the cabinet <NUM>.

Meanwhile, once the drawer panel <NUM> has moved to the position at which the opening <NUM> is closed by the drawer panel <NUM>, the drawer panel <NUM> may come into contact with the flange <NUM>. Accordingly, the flange <NUM> serves not only to arrange the drawer body <NUM> at a reference position, which is set inside the cabinet <NUM>, but also to prevent the drawer panel <NUM> from being inserted into the cabinet <NUM>.

The drawer panel <NUM> may be provided with a control panel <NUM>, which is used to input a control command associated with the operation of the laundry treatment apparatus <NUM> and to notify a user of a message associated with the operation of the laundry treatment apparatus <NUM>. The control panel <NUM> may include an input unit 331a for the input of a control command, and a display unit 331b for displaying signals associated with the operation of the laundry treatment apparatus <NUM> including the control command. The display unit 331b may be at least one selected from among a device for displaying characters or symbols (e.g. an LCD), a device for generating sound (e.g. a speaker), and a device for emitting light (e.g., a lamp).

The drawer body <NUM> may have any shape so long as it can be inserted into the cabinet <NUM> through the opening <NUM> and so long as it can provide a space in which the tub <NUM> is received. <FIG> illustrates the drawer body <NUM> having a hexahedral shape by way of example.

The drawer cover <NUM> has a first through-hole <NUM> and a second through-hole <NUM> for communicating the inside of the drawer body <NUM> with the outside. The first through-hole <NUM> must be provided for the introduction and discharge of laundry, and the second through-hole <NUM> must be provided to supply water required to wash the laundry. A detailed description related thereto will follow.

As exemplarily illustrated in <FIG>, the tub <NUM> includes a tub body <NUM> located inside the drawer body <NUM> for storing water therein, and a tub cover <NUM> for forming the upper surface of the tub body <NUM>. The tub body <NUM> may take the form of a cylinder having an open upper surface.

The tub cover <NUM> may have an introduction aperture <NUM> for communicating the inside of the tub body <NUM> with the outside of the tub body <NUM>, and a supply aperture <NUM> for introducing water into the tub body <NUM>.

The introduction aperture <NUM> may be provided under the first through-hole <NUM> provided in the drawer cover <NUM>, and the supply aperture <NUM> may be provided so as to communicate with the second through-hole <NUM> provided in the drawer cover <NUM>.

The introduction aperture <NUM> serves to allow laundry to be introduced into the tub body <NUM>, or to allow the laundry inside the tub body <NUM> to be discharged to the outside of the tub body <NUM>. The introduction aperture <NUM> is opened and closed by a door <NUM>, which is rotatably provided on any one of the drawer cover <NUM> or the tub cover <NUM>.

<FIG> illustrates the case where the door <NUM> is coupled to the tub cover <NUM>. In this case, the door <NUM> may include a frame <NUM> rotatably coupled to the tub cover <NUM> via a hinge <NUM>, a window <NUM> provided in the frame <NUM>, and a handle <NUM> for separably coupling the frame <NUM> to the tub cover <NUM>.

The window <NUM> may be formed of a transparent material to allow the user to view the inside of the tub body <NUM> when the drawer <NUM> is discharged from the cabinet <NUM>.

The handle <NUM> is rotatably coupled to the frame <NUM> via a handle shaft 457b, and the handle <NUM> is separably fixed to the tub cover <NUM> via a fixing unit <NUM>.

The fixing unit <NUM> may include a first fastening portion <NUM> (e.g. a hook) protruding from any one of the handle <NUM> and the tub cover <NUM>, and a second fastening portion <NUM> (e.g. a hook receiving recess) formed in the other one of the handle <NUM> and the tub cover <NUM> for separably receiving the first fastening portion <NUM>.

The tub body <NUM> may be coupled to the drawer body <NUM> via a tub support unit <NUM>. The tub support unit <NUM> may include a first support member <NUM> provided at the drawer body <NUM>, a second support member <NUM> provided at the tub body <NUM>, and a connector <NUM> for connecting the first support member <NUM> and the second support member <NUM> to each other.

The drum <NUM>, which is provided inside the tub <NUM>, may provided in a form illustrated in <FIG>. That is, the drum <NUM> may include a cylindrical drum body <NUM> having an opening <NUM> (i.e. a drum opening) formed in the upper surface thereof.

Because the drum opening <NUM> is located below the introduction aperture <NUM>, the laundry supplied through the introduction aperture <NUM> may be supplied to the drum body <NUM> through the drum opening <NUM>. Meanwhile, a plurality of drum through-holes <NUM> may be provided in a bottom surface and a circumferential surface of the drum body <NUM> for communicating the inside of the drum body <NUM> with the tub body <NUM>.

The drum body <NUM> may be rotated inside the tub body <NUM> by a drive unit. The drive unit may include a stator M1 located outside the tub body <NUM> and fixed to the bottom surface of the tub body <NUM>, a rotor M2 configured so as to be rotated by a rotating magnetic field provided by the stator M1, and a rotating shaft M3 penetrating the bottom surface of the tub body <NUM> for connecting the bottom surface <NUM> of the drum <NUM> and the rotor M2 to each other. In this case, the rotating shaft M3 may be provided so as to form a right angle with respect to the bottom surface of the tub body <NUM>.

The laundry treatment apparatus <NUM> having the configuration described above may supply water to the tub <NUM> via a water supply unit <NUM>, and may discharge water stored in the tub <NUM> to the outside of the cabinet <NUM> via a drain unit <NUM>.

The water supply unit <NUM> may include a first water supply pipe <NUM> connected to the supply aperture <NUM> formed in the tub cover <NUM>, a second water supply pipe <NUM> connected to a water supply source, which is located at the outside of the cabinet <NUM>, and a connection pipe <NUM> fixed to the drawer cover <NUM> for connecting the first water supply pipe <NUM> and the second water supply pipe <NUM> to each other.

The first water supply pipe <NUM> may connect the supply aperture <NUM> and the connection pipe <NUM> to each other through the second through-hole <NUM> provided in the drawer cover <NUM>. The first water supply pipe <NUM> may be a corrugated pipe in order to prevent the first water supply pipe <NUM> from being separated from the connection pipe <NUM> when the tub <NUM> vibrates.

In addition, the second water supply pipe <NUM> may also be a corrugated pipe in order to prevent the second water supply pipe <NUM> from being separated from the connection pipe <NUM> when the drawer <NUM> is discharged from the cabinet <NUM>. The second water supply pipe <NUM> may be opened and closed by a water supply valve <NUM>, which is controlled by a controller (not illustrated).

Alternatively, unlike the illustration of <FIG>, the water supply unit <NUM> may include a single water supply pipe for connecting a water supply source (not illustrated), which is located at the outside of the cabinet <NUM>, to the supply aperture <NUM> provided in the tub cover <NUM>. In this case, the water supply pipe may be a corrugated pipe.

The drain unit <NUM> may include a drain pump <NUM> fixed to the drawer body <NUM>, a first drain pipe <NUM> for guiding water inside the tub body <NUM> to the drain pump <NUM>, and a second drain pipe <NUM> for guiding water discharged from the drain pump <NUM> to the outside of the cabinet <NUM>. In this case, the second drain pipe <NUM> may be a corrugated pipe.

In the laundry treatment apparatus <NUM> having the configuration described above, it may be difficult to discharge the drawer <NUM> from the cabinet <NUM> when the door <NUM> is opened in the state in which the drawer <NUM> is located inside the cabinet <NUM>. That is, once the door <NUM> has been opened inside the cabinet <NUM>, the door <NUM> may interfere with the introduction/discharge opening <NUM> of the cabinet <NUM> when the drawer <NUM> is discharged from the cabinet <NUM>, thereby preventing the discharge of the drawer <NUM>.

In order to solve the problem described above, the laundry treatment apparatus <NUM> of the present invention may further include a guide <NUM> for preventing the door <NUM> from interfering with the introduction/discharge opening <NUM> when the drawer <NUM> is discharged from the cabinet <NUM>.

As exemplarily illustrated in <FIG>, the guide <NUM> may include at least one wheel rotatably provided inside the cabinet <NUM>. In this case, a distance H2 from the upper surface of the drawer <NUM> to the lowermost end of the wheel <NUM> may be shorter than a distance H1 from the upper surface of the drawer <NUM> to the introduction/discharge opening <NUM>.

The wheel <NUM> may be rotatably fixed to the cabinet <NUM>, or may be fixed to a base <NUM>, which is fixed inside the cabinet <NUM> so as to be located above the door <NUM>. That is, the wheel <NUM> may be rotatably fixed to the base <NUM> via a shaft <NUM>.

Meanwhile, in the case where the introduction/discharge opening <NUM> has the opening <NUM> and the flange <NUM>, the guide <NUM> needs to prevent the door <NUM> from interfering with the flange <NUM> when the drawer <NUM> is discharged from the cabinet <NUM>. In this case, the distance H2 from the drawer cover <NUM> to the lowermost end of the wheel <NUM> may be shorter than a distance from the drawer cover <NUM> to the flange <NUM>.

In addition, the distance from the upper surface of the drawer <NUM> to the lowermost end of the wheel <NUM> may be set to a length for enabling the coupling of the first fastening portion <NUM> and the second fastening portion <NUM> provided in the fixing unit <NUM>. This serves to eliminate a problem in which the door <NUM> prevents the drawer <NUM> from being discharged from the cabinet <NUM> by fixing the door <NUM> to the tub cover <NUM> using the guide <NUM> whenever the drawer <NUM> is discharged from or inserted into the cabinet <NUM>.

The wheel <NUM> may include a first wheel and a second wheel, which are spaced apart from each other by a prescribed distance in the direction in which the drawer <NUM> is discharged (see <FIG>). The distances from the upper surface of the drawer <NUM> to the lowermost ends of the respective wheels may be set to the same value, or may be set to different values. In the latter case, the distance from the upper surface of the drawer <NUM> to the lowermost end of the wheel located close to the introduction/discharge opening <NUM> may be shorter than the distance from the upper surface of the drawer <NUM> to the lowermost end of the other wheel.

Meanwhile, the present invention may further include a first position sensing unit (i.e. a door sensing unit) for determining whether or not the door <NUM> to open the introduction aperture <NUM> is opened inside the cabinet <NUM>.

The first position sensing unit <NUM> may include a first magnetic-force generator <NUM> provided in any one of the cabinet <NUM> and the door <NUM> for generating magnetic force, and a first magnetic-force sensor <NUM> provided in the other one of the cabinet <NUM> and the door <NUM> for sensing the magnetic force provided by the first magnetic-force generator <NUM>.

<FIG> illustrates the case where the first magnetic-force generator <NUM> is a permanent magnet fixed to the door <NUM> and the first magnetic-force sensor <NUM> is fixed to the base <NUM> so as to sense the magnitude of magnetic force of the permanent magnet by way of example.

When the magnitude of magnetic force of the first magnetic-force generator <NUM>, sensed by the first magnetic-force sensor <NUM>, is below a predetermined reference magnetic force (i.e. a first reference magnetic force), the controller (not illustrated) determines that the drawer <NUM> is located inside the cabinet <NUM> and the door <NUM> to open the introduction aperture <NUM> is closed.

However, when the magnitude of magnetic force of the first magnetic-force generator <NUM>, sensed by the first magnetic-force sensor <NUM>, is the first reference magnetic force or more, the controller (not illustrated) determines that the door <NUM> located inside the cabinet <NUM> to open the introduction aperture <NUM> is opened.

Upon determining that the door <NUM> to open the introduction aperture <NUM>, located inside the cabinet <NUM>, is opened, the controller (not illustrated) may notify the user that the door <NUM> inside the cabinet <NUM> is opened via, for example, the display unit 331b.

Meanwhile, when the first magnetic-force generator <NUM> is provided in the door <NUM>, the first magnetic-force generator <NUM> may vibrate simultaneously with the vibration of the tub <NUM>. When the first magnetic-force generator <NUM> vibrates, the distance between the first magnetic-force generator <NUM> and the first magnetic-force sensor <NUM> varies, thus causing variation in the magnitude of magnetic force measured by the first magnetic-force sensor <NUM>. Therefore, when the first magnetic-force generator <NUM> is provided in the door <NUM>, the controller may incorrectly determine that the door <NUM> to open the introduction aperture <NUM> is opened even though the introduction aperture <NUM> is closed by the door <NUM>.

To solve the problem described above, the controller may determine whether the magnetic force measured by the first magnetic-force sensor <NUM> is greater than or equal to the first reference magnetic force, and then may determine that the introduction aperture <NUM> is opened only when a state in which the measured magnetic force is the first reference magnetic force or more is continued during a predetermined reference time or more.

That is, the display unit 331b may display character signals or symbols, generate sound signals, or emit light only when the state in which the magnetic force measured by the first magnetic force sensor <NUM> is the first reference magnetic force or more is continued during the reference time or more.

The reference time may be set to a longer time than a time required to rotate the drum <NUM> once. For example, assuming the case where the drum <NUM> is set to be rotated at <NUM> RPM, the time required to rotate the drum <NUM> once is <NUM> seconds. When the drum <NUM> vibrates because laundry inside the drum <NUM> is not evenly distributed, the vibration of the drum <NUM> may be transmitted to the tub <NUM> whenever the drum <NUM> is rotated once. That is, the vibration of the drum <NUM> may be transmitted to the tub <NUM> for the period of time required to rotate the drum <NUM> once (i.e. <NUM> seconds). Accordingly, when the reference time is set to a longer time than the period during which the vibration of the drum <NUM> is transmitted to the tub <NUM> (<NUM> seconds), it is possible to prevent variation in magnetic force attributable to the vibration of the tub <NUM> or the door <NUM> from being incorrectly determined to be the opening of the door <NUM>.

Meanwhile, the problem of incorrectly determining that the door <NUM> to open the introduction aperture <NUM> is opened even though the introduction aperture <NUM> is closed by the door <NUM> is solved using a first position sensing unit <NUM> illustrated in <FIG> and <FIG>.

In the case of the first position sensing unit <NUM> illustrated in <FIG> and <FIG>, both the first magnetic-force sensor <NUM> and the first magnetic-force generator <NUM> are not provided in the door <NUM>. Thus, even if the tub <NUM> or the door <NUM> vibrates, the magnetic force of the first magnetic-force generator <NUM> measured by the first magnetic-force sensor <NUM> may be maintained at a relatively constant value.

The first position sensing unit <NUM> of <FIG> includes the first magnetic-force sensor <NUM> provided in the base <NUM> for sensing magnetic force, a body <NUM> configured so as to be rotated toward the first magnetic-force sensor <NUM> when the door <NUM> to open the introduction aperture <NUM> is opened, and the first magnetic-force generator <NUM> fixed to the body <NUM>.

The body <NUM> extends from the base <NUM> toward the door <NUM>, and is rotatably coupled to the base <NUM> via a body rotating shaft <NUM>. In addition, the first position sensing unit <NUM> may further include a contact portion <NUM>, which protrudes from the body <NUM> toward the door <NUM> so as to come into contact with the door <NUM> when the door <NUM> to the introduction aperture <NUM> is opened.

When the door <NUM> to open the introduction aperture <NUM> is opened in the state in which the drawer <NUM> is inserted into the cabinet <NUM>, the body <NUM> may be moved toward the first magnetic-force sensor <NUM> by the door <NUM>, and therefore the magnetic force of the first magnetic-force generator <NUM> sensed by the first magnetic-force sensor <NUM> is increased.

Accordingly, when the magnitude of magnetic force of the first magnetic-force generator <NUM>, sensed by the first magnetic-force sensor <NUM>, is the first reference magnetic-force or more, the controller (not illustrated) may determine that the door <NUM> to open the introduction aperture <NUM> is opened. Upon determining that the door <NUM> to open the introduction aperture <NUM> is opened, the controller may notify the user that the door <NUM> is opened via the display unit 331b. Through the process described above, the present invention may notify the user that the door to open the introduction aperture <NUM> is opened.

Meanwhile, although the possibility of the first position sensing unit <NUM> of <FIG> incorrectly determining that the door <NUM> to open the introduction aperture <NUM> is opened is low even if the tub <NUM> or the door <NUM> vibrates the because both the first magnetic-force sensor <NUM> and the first magnetic-force generator <NUM> are fixed to the base <NUM>, the first position sensing unit <NUM> may have a risk of incorrectly determining that the door <NUM> to open the introduction aperture <NUM> is opened when the cabinet <NUM> vibrates.

To solve the problem described above, whether or not the magnetic force measured by the first magnetic-force sensor <NUM> is equal to or greater than the first reference magnetic force may be determined, and only when the state in which the measured magnetic force is the first reference magnetic force or more is continued during the reference time or more, the controller may determine that the introduction aperture <NUM> is opened by the door <NUM>.

That is, the display unit 331b may display character signals or symbols, may generate sound signals, or may emit light only when the state in which the magnetic force measured by the first magnetic-force sensor <NUM> is equal to or greater than the first reference magnetic force is continued during the reference time or more. The reference time may be set to a longer time than a period during which vibration of the drum <NUM> is transmitted to the tub <NUM>.

Meanwhile, the first position sensing unit <NUM> of <FIG> disadvantageously has no function of determining whether or not the first magnetic-force generator <NUM> is separated from the body <NUM> even though the first magnetic-force generator <NUM> is separated from the body <NUM> due to vibration of the laundry treatment apparatus <NUM> or other reasons.

The first position sensing unit <NUM> of <FIG> may be devised to solve the above-described problem of the first position sensing unit <NUM> of <FIG>. The first position sensing unit <NUM> in accordance with the present embodiment may include the first magnetic-force sensor <NUM> fixed to the base <NUM> located above the door <NUM>, the body <NUM> configured so as to be rotated away from the first magnetic-force sensor <NUM> when the door <NUM> to open the introduction aperture <NUM> is opened, and the first magnetic-force generator <NUM> fixed to the body <NUM>.

The body <NUM> extends from the base <NUM> toward the first magnetic-force sensor <NUM>. The body <NUM> may be rotatably fixed to the base <NUM> via a body rotating shaft (not illustrated). When the body <NUM> is formed of an elastic material, such as rubber, the body <NUM> may be fixed to the base <NUM> via a body fastening portion <NUM>.

The body <NUM> may be provided with the body contact portion <NUM>, which protrudes toward the door <NUM> so as to come into contact with the door <NUM> when the door <NUM> to open the introduction aperture <NUM> is opened.

In order to prevent the body <NUM> from being rotated toward the drawer <NUM> or the door <NUM>, the base <NUM> may further be provided with a body support portion <NUM> for preventing the body <NUM> from being rotated toward the door <NUM>. The body support portion <NUM> may be provided so as to directly support the body <NUM>, and may be provided so as to support a body protruding portion <NUM> provided on the body <NUM>.

In the case of the present embodiment, the magnetic force of the first magnetic-force generator <NUM> measured by the first magnetic-force sensor <NUM> becomes the maximum when the door <NUM> to open the introduction aperture <NUM> is closed, and becomes the minimum when the door <NUM> to open the introduction aperture <NUM> is opened. Accordingly, the controller (not illustrated) determines that the door <NUM> to open the introduction aperture <NUM> is opened when the magnitude of magnetic force sensed by the first magnetic-force sensor <NUM> is below the first reference magnetic force.

Upon determining that the door <NUM> to open the introduction aperture <NUM> is opened, the controller may notify the user that the door <NUM> is opened via the display unit 331b. Therefore, the present embodiment may notify the user of whether or not the current state is the state in which the door <NUM> to open the introduction aperture <NUM> is opened.

In the present embodiment, the controller may also determine whether or not the magnetic force measured by the first magnetic-force sensor <NUM> is below the first reference magnetic force, and may determine that the introduction aperture <NUM> is opened only when the state in which the measured magnetic force is below the first reference magnetic force is continued during the reference time or more.

In this case, the display unit 331b may display character signals or symbols, may generate sound signals, or may emit light only when the state in which the measured magnetic force is below the first reference magnetic force is continued during the reference time or more. The reference time may be set to a time, which is longer than the period during which vibration of the drum <NUM> is transmitted to the tub <NUM>.

Meanwhile, in the present embodiment, when the first magnetic-force sensor <NUM> fails to sense the magnetic force of the first magnetic-force generator <NUM> in the state in which the drawer <NUM> is discharged from the cabinet <NUM>, the controller (not illustrated) may determine that the first magnetic-force generator <NUM> is separated from the body <NUM>, and may notify the user of the result of determination.

In addition to the first position sensing unit <NUM> described above, the laundry treatment apparatus <NUM> of the present invention may further include a second position sensing unit <NUM> (i.e. a drawer sensing unit) for determining whether or not the drawer <NUM> is inserted to the inside of the cabinet <NUM>. The second position sensing unit <NUM> may serve to determine whether or not the drawer <NUM> is located at a predetermined reference position. In one example, the reference position may be a position at which the introduction/discharge opening <NUM> is closed by the drawer panel <NUM>.

The second position sensing unit <NUM> may include a second magnetic-force generator <NUM> provided in any one of the drawer <NUM> and the cabinet <NUM> for generating magnetic-force, and a second magnetic-force sensor <NUM> provided in the other one of the drawer <NUM> and the cabinet <NUM> for sensing the magnitude of magnetic force provided by the second magnetic-force generator <NUM>.

The second magnetic-force sensor <NUM> and the second magnetic-force generator <NUM> may be provided at positions at which whether or not the introduction/discharge opening <NUM> is closed by the drawer panel <NUM> may be determined. <FIG> illustrate the case where the second magnetic-force generator <NUM> is a permanent magnet fixed to the front side of the drawer cover <NUM> and the second magnetic-force sensor <NUM> is fixed to the base <NUM> for sensing the magnitude of magnetic force of the permanent magnet.

When the drawer <NUM> is not completely inserted into the cabinet <NUM>, but is operated, the drawer <NUM> may be discharged from the cabinet <NUM> by vibration generated during rotation of the drum <NUM>.

To solve the problem described above, the controller (not illustrated) may notify the user that the magnitude of magnetic force sensed by the second magnetic-force sensing unit <NUM> is below a predetermined reference magnetic-force (i.e. a second reference magnetic force) via the display unit 331b (using character signals, symbols, sound signals, and light emission).

As is apparent from the above description, the present invention, the present invention has the effect of providing a laundry treatment apparatus, which may notify a user that a door to open an introduction aperture is opened in the state in which a drawer is inserted into a cabinet.

In addition, the present invention has the effect of providing a laundry treatment apparatus, which may allow a drawer to be discharged from a cabinet even if a door to open an introduction aperture is opened in the state in which the drawer is inserted into the cabinet.

In addition, the present invention has the effect of providing a laundry treatment apparatus, which may determine whether or not a drawer is inserted into a cabinet and may notify a user of the result of the determination.

In addition, the present invention has the effect of providing a laundry treatment apparatus, which may rapidly sense that a door is opened when a drawer is inserted into a cabinet.

In addition, the present invention has the effect of providing a laundry treatment apparatus, which may accurately determine the occurrence of abnormalities in constituent elements for determining whether or not a door is opened.

Claim 1:
A laundry treatment apparatus comprising:
a cabinet (<NUM>) to form the external appearance of the laundry treatment apparatus (<NUM>), the cabinet (<NUM>) having an opening (<NUM>);
a drawer (<NUM>) configured to be withdrawable from the cabinet (<NUM>) through the opening (<NUM>);
a tub (<NUM>) provided inside the drawer (<NUM>) and configured to receive water;
an introduction aperture (<NUM>) provided to penetrate the upper surface of the tub (<NUM>); and
a drum (<NUM>) rotatably provided inside the tub (<NUM>) for receiving laundry supplied to the introduction aperture (<NUM>);
characterized by:
a door (<NUM>) configured to open and close the introduction aperture (<NUM>), the door (<NUM>) being coupled to one of the drawer (<NUM>) or the tub (<NUM>) and
a door sensing unit (<NUM>) configured to sense whether or not the door (<NUM>) to open the introduction aperture (<NUM>) is opened,
wherein the door sensing unit (<NUM>) includes:
a magnetic-force sensor (<NUM>) provided at the inner side of the cabinet (<NUM>) facing the upper surface of the door (<NUM>), and
a magnetic-force generator (<NUM>) rotatably provided at the inner side of the cabinet (<NUM>) and spaced apart from the magnetic-force sensor (<NUM>),
wherein a distance between the sensor (<NUM>) and the magnetic-force generator (<NUM>) is changed as the door (<NUM>) opens the introduction aperture (<NUM>) and the door (<NUM>) rotates the magnetic-force generator (<NUM>).