Patent Description:
An autonomous robot is a device for performing a desired task while traveling about a certain region without being operated by a user. Such a robot may substantially operate autonomously. Autonomous operation may be achieved in various manners. In particular, a robot cleaner is a device for removing dust from a floor while traveling about a region to be cleaned without being operated by a user. In detail, such a robot cleaner may perform a vacuum cleaning operation and a wiping operation in a home. Here, dust may mean (soil) dust, mote, powder, debris, and other dust particles.

An example of a cleaning robot is known from <CIT>.

Therefore, it is an aspect of the present disclosure to provide a cleaning system capable of preventing the cleaning performance of a robot cleaner from being degraded.

In accordance with one aspect of the present disclosure, a robot cleaner includes a body having an opening, a dust box provided at the body, to store dust, and a brush unit provided at the opening of the body, to sweep dust on a floor into the dust box, wherein the dust swept into the dust box is suspended in air introduced into the dust box through the opening of the body, and is then discharged through the opening of the body.

The air may be introduced into the dust body through a side region of the opening of the body, and may then be outwardly discharged through a central region of the opening of the body.

The robot cleaner may further include a brush unit provided at the body such that the brush unit is rotatable. The brush unit may be controlled to allow dust to be more effectively discharged.

The brush unit may include a roller, and the roller of the brush unit changes a rotation direction at least one time during the dust discharge.

During the dust discharge, the roller of the brush unit may rotate slowly in an initial period of time when light dust is discharged, and may then rotate rapidly.

The robot cleaner may further include a maintenance station to generate a flow to discharge air toward the body, and a flow to suck air from the body. The opening of the body may communicate with an opening provided at the maintenance station.

In accordance with another aspect of the present disclosure, a maintenance station blows air into a dust box included in a robot cleaner through an opening of the robot cleaner where a brush unit is installed, and sucks dust stored in the dust box while being suspended in the air blown into the dust box.

The air sucked from the dust box of the robot cleaner may be re-blown into the dust box through the opening of the robot cleaner.

The maintenance station may further include an opening to communicate with the opening of the robot cleaner. The dust stored in the dust box of the robot cleaner may be discharged to the opening of the robot cleaner, so as to be introduced into the opening of the maintenance station.

The maintenance station may further include a pump unit, a suction duct provided at a suction side of the pump unit, and a discharge duct provided at a discharge side of the pump unit. The suction duct may have a suction port arranged at the opening of the maintenance station, and the discharge duct may have a discharge port arranged at the opening of the maintenance station.

The maintenance station may further include a pump unit, a suction duct provided at a suction side of the pump unit, and a discharge duct provided at a discharge side of the pump unit. The suction duct may have a suction port arranged at the opening of the maintenance station. The discharge duct may have a discharge port. The suction port and the discharge port may form the opening of the maintenance station.

The suction port of the suction duct may be formed at a large region of the opening in the maintenance station in a longitudinal direction of the opening, and the discharge port of the discharge duct may be formed at an end region of the opening as viewed in the longitudinal direction of the opening.

The suction port of the suction duct may have a larger cross-sectional area than the discharge port of the discharge duct.

The maintenance station may further include a dust box arranged between the suction duct and the pump unit. Air discharged from the pump unit may be circulated to the pump unit after sequentially passing through the discharge duct, the opening of the robot cleaner, the dust box of the robot cleaner, the opening of the robot cleaner, the suction duct, and the dust box of the maintenance station.

The discharge duct may include a first discharge duct having a first discharge port to allow air to be blown into a larger dust box included in the dust box of the robot cleaner, and a second discharge port to allow air to be blown into a smaller dust box included in the dust box of the robot cleaner.

The first and second discharge ports of the first discharge duct may be arranged at opposite ends of the second opening in a width direction in one side region of the second opening, respectively.

The discharge duct may include a second discharge duct having a third discharge port to allow air to be blown into a larger dust box included in the dust box of the robot cleaner, and a fourth discharge port to allow air to be blown into a smaller dust box included in the dust box of the robot cleaner.

The third and fourth discharge ports of the first discharge duct may be arranged at opposite ends of the second opening in a width direction in the other side region of the second opening, respectively.

The maintenance station may further include a suction/discharge dual tube to guide air to be blown to a sensor provided at the robot cleaner and to be again sucked from the sensor.

The maintenance station may further include a pump unit, a suction duct provided at a suction side of the pump unit, and a discharge duct provided at a discharge side of the pump unit. The suction duct may communicate with a suction tube of the suction/discharge dual tube, and the discharge duct may communicate with a discharge tube of the suction/discharge dual tube.

The maintenance station may further include a pump unit, a suction duct provided at a suction side of the pump unit, and a port assembly to divide the suction duct into two portions respectively having first and second suction ports.

The port assembly may include a suction port forming member to form the first and second suction ports.

The second suction port may surround at least a portion of the first suction port.

The first suction port may be provided at a position substantially corresponding to the opening of the robot cleaner. At least a portion of the second suction port is arranged outside the opening of the robot cleaner.

A cover having a plurality of through holes may be provided at the second suction port.

The maintenance station may further include a pump unit, first and second discharge ducts provided at a discharge side of the pump unit, and a port assembly to divide the first discharge duct into two portions respectively having first and second discharge ports, and to divide the second discharge duct into two portions respectively having third and fourth discharge ports.

The port assembly may include a first discharge port forming member to form the first discharge port, a second discharge port forming member to form the second discharge port, a third discharge port forming member to form the third discharge port, and a fourth discharge port forming member to form the fourth discharge port.

The second suction port may surround at least a portion of each of the first, second, third and fourth discharge ports.

The port assembly may further include a plurality of brush cleaning members to clean the brush unit of the robot cleaner.

Each of the plural brush cleaning members may include a guide extending inclinedly with respect to a rotation direction of the brush unit, and at least one hook protruded from a side surface of the guide.

The port assembly may be detachably mounted to the opening of the maintenance station.

The port assembly may further include a first spacer provided at a bottom of the port assembly, and second spacers provided at opposite sides of the first spacer.

The opening of the maintenance station may be larger than the opening of the robot cleaner.

The maintenance station may further include a pump unit, and a suction duct provided at a suction side of the pump unit. The suction duct may have a suction port, which is larger than the opening of the robot cleaner.

In accordance with another aspect of the present disclosure, a cleaning system includes a robot cleaner including a first opening, and a first dust box communicating with the first opening, and a maintenance station including a second opening, and a second dust box communicating with the second opening, wherein dust stored in the first dust box of the robot cleaner is discharged to the second opening of the maintenance station through the first opening of the robot cleaner after being suspended in air introduced into the first dust box of the robot cleaner.

The air introduced into the first dust box of the robot cleaner may pass through the first opening of the robot cleaner.

The cleaning system may further include a dust removal unit to suck air from the first dust box of the robot cleaner through the first opening of the robot cleaner, and to again blow air to the first opening of the robot cleaner.

The dust removal unit may suck air such that the air blown to the first opening of the robot cleaner emerges from the first opening of the robot cleaner after circulating through the first dust box of the robot cleaner.

The dust removal unit may blow air in a side region of the first opening of the robot cleaner as viewed in a longitudinal direction of the first opening, and may suck air in a large region of the first opening as viewed in the longitudinal direction of the first opening.

The dust removal unit may include a pump unit, and a first discharge duct provided at a discharge side of the pump unit. The first discharge duct may have a first discharge port to allow air to be blown into a larger dust box included in the first dust box, and a second discharge port to allow air to be blown into a smaller dust box included in the first dust box.

The dust removal unit may further include a second discharge duct provided at the discharge side of the pump unit. The second discharge duct may have a third discharge port to allow air to be blown into the larger dust box of the first dust box, and a fourth discharge port to allow air to be blown into a smaller dust box included in the first dust box.

The dust removal unit may include a pump unit, and a suction duct provided at a suction side of the pump unit. The suction duct may have a suction port, which is larger than the opening of the robot cleaner.

The dust removal unit may include a pump unit, a suction duct provided at a suction side of the pump unit, first and second discharge ducts provided at a discharge side of the pump unit, and a port assembly to divide the suction duct into two portions respectively having first and second suction ports, to divide the first discharge duct into two portions respectively having first and second discharge ports, and to divide the second discharge duct into two portions respectively having third and fourth discharge ports.

The port assembly may include a suction port forming member to form the first and second suction ports, a first discharge port forming member to form the first discharge port, a second discharge port forming member to form the second discharge port, a third discharge port forming member to form the third discharge port, and a fourth discharge port forming member to form the fourth discharge port.

The second suction port may surround the first suction port, the first discharge port, the second discharge port, the third discharge port, and the fourth discharge port.

The dust removal unit may include a pump unit, a suction duct provided at a suction side of the pump unit, and a discharge duct provided at a discharge side of the pump unit. The suction duct may have a suction port arranged in a large region of the first opening of the robot cleaner in a longitudinal direction of the first opening, and the discharge duct may have a discharge port arranged at a side region of the first opening as viewed in the longitudinal direction of the first opening.

A cross-sectional area ratio between the suction port of the suction duct and the discharge port of the discharge duct may be <NUM>:<NUM>.

The suction port of the suction duct and the discharge port of the discharge duct may form the second opening of the maintenance system.

The maintenance station may further include a cover to open or close the second opening of the maintenance station.

The maintenance station may further include a bridge extending along a central portion of the second opening of the maintenance station.

The robot cleaner may further include a brush unit provided at the first opening of the robot cleaner. The brush unit may be controlled to allow dust stored in the first dust box of the robot cleaner to be more effectively discharged to the second opening of the maintenance station.

The roller may rotate slowly in an initial period of time when light dust is discharged, and may then rotate rapidly.

The maintenance station may further include a brush cleaning member to clean the brush unit.

The brush cleaning member may be arranged adjacent to the second opening of the maintenance station.

The brush cleaning member may include a guide extending inclinedly with respect to a rotation direction of the brush unit, and at least one hook protruded from a side surface of the guide.

The robot cleaner may further include a dust sensing unit to sense an amount of dust stored in the first dust box. The dust sensing unit may include a light emitting sensor and a light receiving sensor, which are installed at regions other than the first dust box, and a reflecting member installed in the first dust box, to reflect a signal transmitted from the light emitting sensor to the light receiving sensor.

The robot cleaner may further include a dust sensing unit to sense an amount of dust stored in the first dust box. The robot cleaner may be moved to the maintenance station when the dust amount sensed by the dust sensing unit corresponds to a predetermined amount or more.

In accordance with another aspect of the present disclosure, a cleaning system includes docking a robot cleaner at a maintenance station, determining whether or not docking is completed, discharging dust stored in the robot cleaner into the maintenance station through an opening where a brush unit included in the robot cleaner is installed, upon completion of docking, and operating a brush unit of the robot cleaner during dust discharge.

The brush unit may change a rotation direction at least one time.

The brush unit may rotate slowly in an initial period of time when light dust is discharged, and may then rotate rapidly.

The cleaning system may further include determining whether or not dust is completely filled in a dust box of the robot cleaner.

In accordance with another aspect of the present disclosure, a robot cleaner includes a body, a dust box provided at the body, to store dust, and a dust sensing unit to measure an amount of dust stored in the dust box, wherein the dust sensing unit includes a light emitting sensor installed at a region other than the dust box, to transmit a signal to an interior of the dust box, and a light receiving sensor installed at a region other than the dust box, to sense a signal emerging from the interior of the dust box.

The dust sensing unit may further include a reflecting member installed within the dust box, to reflect the signal transmitted from the light emitting sensor to the light receiving sensor.

The dust box may include at least one inlet, through which dust is introduced into the dust box. The light emitting sensor and the light receiving sensor may be provided at a portion of the body corresponding to the inlet of the dust box, to perform signal transmission and signal reception through the inlet of the dust box, respectively.

The robot cleaner may further include a display provided at the body, to display various information. The display unit may display dust sensing information from the dust sensing unit.

There may be no connecting terminal connected to the dust box.

In accordance with another aspect of the present disclosure, a robot cleaner may include a body, a dust box provided at the body, to store dust, and a dust sensing unit to measure an amount of dust stored in the dust box. The dust sensing unit may include a light emitting sensor installed at a region other than the dust box. A signal transmitted from the light emitting sensor may reach the light receiving sensor after passing through the dust box.

The dust box may be made of a transparent material to allow a signal to pass through the dust box.

The light emitting sensor and the light receiving sensor may be installed so as to face each other.

The dust box may include a transmitted-signal passing portion arranged at a position corresponding to the light emitting sensor, to allow a signal to enter the dust box, and a received-signal passing portion arranged at a position corresponding to the light receiving sensor, to allow a signal to emerge from the dust box.

The transmitted-signal passing portion and the received-signal passing portion may be made of a transparent material.

Hereinafter, a robot cleaner, a maintenance station, and a cleaning system according to embodiments of the present disclosure will be described with reference to the accompanying drawings.

<FIG> is a view illustrating a cleaning system according to an exemplary embodiment of the present disclosure.

As shown in <FIG>, the cleaning system <NUM> may include a robot cleaner <NUM> and a maintenance station <NUM>. The robot cleaner <NUM> is a device for autonomously performing various cleaning tasks. The maintenance station <NUM> is a device for repair and maintenance. The maintenance station <NUM> may charge a battery of the robot cleaner <NUM>, and empties a dust box of the robot cleaner <NUM>.

<FIG> is a sectional view illustrating a configuration of the robot cleaner according to an exemplary embodiment of the present disclosure. <FIG> is a perspective view illustrating a bottom of the robot cleaner according to the illustrated embodiment of the present disclosure.

As shown in <FIG>, the robot cleaner <NUM> includes a body <NUM>, a driving unit <NUM>, a cleaning unit <NUM>, various sensors <NUM>, and a controller (not shown).

The body <NUM> may have various shapes. For example, the body <NUM> may have a circular shape. Where the body <NUM> has a circular shape, it may be prevented from coming into contact with surrounding obstacles and may easily achieve direction change, even during rotation thereof, because it has a constant radius of rotation. Also, it may be possible to prevent the body <NUM> from being obstructed by a surrounding obstacle during travel thereof. Thus, the body <NUM> cannot be trapped by an obstacle during travel thereof.

Various constituent elements to perform cleaning tasks, that is, the driving unit <NUM>, cleaning unit <NUM>, various sensors <NUM>, controller (not shown), and a display <NUM>, may be installed on the body <NUM>.

The driving unit <NUM> may enable the body <NUM> to travel about a region to be cleaned. The driving unit <NUM> may include left and right driving wheels 31a and 31b, and a caster <NUM>. The left and right driving wheels 31a and 31b are mounted to a central portion of a bottom of the body <NUM>. The caster <NUM> is mounted to a front portion of the bottom of the body <NUM>, to maintain stability of the robot cleaner <NUM>.

The left and right driving wheels 31a and 31b may be controlled to move the robot cleaner <NUM> forward or backward, or to change the running direction of the robot cleaner <NUM>. For example, it may be possible to move the robot cleaner <NUM> forward or backward by uniformly controlling the left and right driving wheels 31a and 31b. Also, it may be possible to change the running direction of the robot cleaner <NUM> by differently controlling the left and right driving wheels 31a and 31b.

Meanwhile, each of the left and right driving wheels 31a and 31b, and the caster <NUM> may be configured into a single assembly detachably mounted to the body <NUM>.

The cleaning unit <NUM> may clean the region underneath the body <NUM> and surrounding portions thereof. The cleaning unit <NUM> may include a brush unit <NUM>, a side brush <NUM>, and a first dust box <NUM>.

The brush unit <NUM> may be mounted to a first opening 21a formed through the bottom of the body <NUM>. The brush unit <NUM> may be arranged at a position other than the central portion of the body <NUM>. That is, the brush unit <NUM> may be arranged at a position adjacent to the driving wheels 31a and 31b while being spaced apart from the driving wheels 31a and 31b in a rearward direction R of the body <NUM>.

The brush unit <NUM> may sweep dust accumulated on a floor beneath the body <NUM> into the first dust box <NUM>. The brush unit <NUM> may include a roller 41a rotatably mounted to the first opening 21a, and a brush 41b fixed to an outer peripheral surface of the roller 41a. When the roller 41a rotates, the brush 41b, which is made of an elastic material, may sweep up dust accumulated on the floor. In accordance with this sweeping operation, the dust accumulated on the floor may be collected in the first dust box <NUM> through the first opening 21a.

The brush unit <NUM> may be controlled to rotate at a constant speed, in order to exhibit a uniform cleaning performance. When the brush unit <NUM> cleans a rough floor surface, the rotating speed thereof may be lowered, as compared to the case in which the brush unit <NUM> cleans a smooth floor surface. In this case, an increased amount of current may be supplied to keep the speed of the brush unit <NUM> constant.

The side brush <NUM> may be rotatably mounted to a peripheral portion of the bottom of the body <NUM> at one side of the body <NUM>. The side brush <NUM> may be mounted at a position spaced apart from the central portion of the body <NUM> in a forward direction F while being biased toward one side of the body <NUM>.

The side brush <NUM> may move dust accumulated around the body <NUM> to the brush unit <NUM>. The side brush <NUM> may expand the cleaning zone of the robot cleaner <NUM> to the bottom of the body <NUM> and surroundings thereof. The dust moved to the brush unit <NUM> may be collected in the first dust box <NUM> through the first opening 21a, as described above.

The first dust box <NUM> may be mounted to a rear portion of the body <NUM>. The first dust box <NUM> includes an inlet <NUM>' communicating with the first opening 21a, to allow dust to be introduced into the first dust box <NUM>.

The first dust box <NUM> may be divided into a larger dust box 43a and a smaller dust box 43b by a partition 43c. The brush unit <NUM> may sweep dust having a relatively-large size into the larger dust box 43a via the first inlet 43a'. A fan unit <NUM> may be provided to suck small-size dust such as hairs via a second inlet 43b', and thus to collect the dust in the smaller dust box 43b. In particular, a brush cleaning member <NUM> c is arranged at a position adjacent to the second inlet 43b'. The brush cleaning member <NUM> c removes hairs wound around the brush unit <NUM>, and then collects the removed hairs in the smaller dust box 43b via the second inlet 43b', using a suction force of the fan unit <NUM>.

Meanwhile, each of the brush unit <NUM>, side brush <NUM>, and first dust box <NUM> may be configured into a single assembly detachably mountable to the body <NUM>.

<FIG> is a plan view illustrating a dust sensing unit according to an exemplary embodiment not covered by the subject-matter of the claims. <FIG> is a plan view illustrating a dust sensing unit according to another exemplary embodiment not covered by the subject-matter of the claimsof the present disclosure. <FIG> is a plan view illustrating a dust sensing unit according to another exemplary embodiment of the present disclosure.

As shown in <FIG>, the dust sensing unit may be installed within the first dust box <NUM>, in order to sense the amount of dust in the first dust box <NUM>.

In this case, the dust sensing unit <NUM> may include a light emitting sensor 44a and a light receiving sensor 44b. A signal transmitted from the light emitting sensor 44a within the first dust box <NUM> may be directly received by the light receiving sensor 44b.

Each of the light emitting sensor 44a and light receiving sensor 44b may include a photodiode or a phototransistor. In this case, it may be possible to determine whether or not the first dust box <NUM> is completely filled with dust, based on the amount of energy sensed by the photodiode or phototransistor. That is, as dust is accumulated in the first dust box <NUM>, the amount of energy sensed by the photodiode or phototransistor may be considerably reduced. Through comparison of the sensed energy amount with a predetermined reference value, the controller may determine that the first dust box <NUM> is completely filled with dust, when the sensed energy amount is less than the reference value. Since the light emitting sensor 44a and light receiving sensor 44b, which are configured by photodiodes or phototransistors, are considerably influenced by disturbance, it may be possible to more accurately sense the amount of dust where a structure such as a slit or a light guide is installed to guide a signal transmitted from the light emitting sensor 44a or a signal received by the light receiving sensor 44b.

Each of the light emitting sensor 44a and light receiving sensor 44b may also be configured by a remote-controller receiving module. In this case, it may be possible to determine whether or not the first dust box <NUM> is completely filled with dust, based on whether or not a signal has been received by the light receiving sensor 44b. That is, when dust is accumulated, the light receiving sensor 44b may not receive a signal transmitted from the light emitting sensor 44a.

In this case, the controller may determine that the amount of dust in the first dust box <NUM> corresponds to a predetermined amount or more. The light emitting sensors 44a and light receiving sensor 44b, which are remote-controller receiving modules, may not require a slit or light guide structure because they filter low-frequency waves while exhibiting high intensity and sensitivity.

For the signal transmitted from the light emitting sensor 44a and received by the light receiving sensor 44b, visible light, infrared light, sound waves, ultrasonic waves, etc. may be used.

Meanwhile, as shown in <FIG>, the dust sensing unit <NUM> may include a light emitting sensor 44a, a light receiving sensor 44b, and a reflecting member 44c.

In this case, the light emitting sensor 44a and light receiving sensor 44b are not installed within the first dust box <NUM>, but are instead installed in an area other than the first dust box <NUM>. That is, the light emitting sensor 44a and light receiving sensor 44b may be installed at a portion of the body <NUM> facing the first dust box <NUM>. In detail, the light emitting sensor 44a and light receiving sensor 44b may be installed adjacent to the inlet <NUM>' of the first dust box <NUM>. In this case, accordingly, the light emitting sensor 44a may transmit a signal into the first dust box <NUM> through the inlet <NUM>'. The light receiving sensor 44b may receive the signal, which emerges from the first dust box <NUM> through the inlet <NUM>' of the first dust box <NUM>.

The reflecting member 44c may be installed within the first dust box <NUM>. The reflecting member 44c may reflect a signal emitted from the light emitting sensor 44a toward the light receiving sensor 44b.

When the first dust box <NUM> is completely filled with dust in this case, the reflecting member 44c is shielded by the dust, so that the signal emitted from the light emitting sensor 44a cannot be received by the light receiving sensor 44b, or the amount of energy received by the light receiving sensor 44b is considerably reduced. In this state, accordingly, the controller may determine that the first dust box <NUM> is filled with a predetermined amount of dust or more.

Meanwhile, where the light emitting sensors 44a and light receiving sensors 44b are configured by remote-controller modules, it may be unnecessary to use a slit or light guide structure because the light emitting sensors 44a and light receiving sensors 44b filter low-frequency waves while exhibiting high intensity and sensitivity, as described above. That is, the light emitting sensors 44a and light receiving sensors 44b, which are configured by remote-controller modules, may determine whether or not the first dust box <NUM> is completely filled with dust, even though there is no structure such as the reflecting member 44c within the first dust box <NUM>.

Since the light emitting sensor 44a and light receiving sensor 44b may not be installed within the first dust box <NUM>, as described above, it may be unnecessary to install an electrical connecting terminal within the first dust box <NUM>. Accordingly, the user may clean the first dust box <NUM>, using water.

The dust sensing unit <NUM> may also include a light emitting sensor 44a and a light receiving sensor 44b, which are configured as shown in <FIG>.

In this case, the light emitting sensor 44a and light receiving sensor 44b need not be installed within the first dust box <NUM>, and may instead be installed at regions other than the first dust box <NUM>. That is, the light emitting sensors 44a and light receiving sensors 44b may be installed on the body <NUM>, to face each other. In detail, the light emitting sensor 44a may be installed at a portion of the body <NUM> facing one side of the first dust box <NUM>, whereas the light receiving sensor 44b may be installed at another portion of the body <NUM> facing the other side of the first dust box <NUM>. In this case, the first dust box <NUM> is arranged between the light emitting sensor 44a and the light receiving sensor 44b, so that a signal transmitted from the light emitting sensor 44a may be received by the light receiving sensor 44b through the first dust box <NUM>. The first dust box <NUM> may be formed to be completely transparent, so as to allow a signal to pass therethrough. The first dust box <NUM> may include a transparent transmitted-signal passing portion 43a" at a position corresponding to the light emitting sensor 44a, in order to allow a signal to pass therethrough, and a transparent received-signal passing portion 43b" at a position corresponding to the light receiving sensor 44b, in order to allow a signal to pass therethrough.

The signal transmitted from the light emitting sensor 44a may be directly received by the light receiving sensor 44b. When the first dust box <NUM> is completely filled with dust, the light receiving sensor 44b does not sense any signal, or the amount of energy sensed by the light receiving sensor 44b may be considerably reduced. In this case, the controller may determine that the first dust box <NUM> is completely filled with dust.

Since an electrical connecting structure is not installed within the first dust box <NUM>, it may be possible to clean the first dust box <NUM>, using water.

When the dust sensing unit <NUM> senses a predetermined amount of dust or more, the robot cleaner <NUM> may display information about the sensed result on the display <NUM>. The user may directly clean the first dust box <NUM>. Meanwhile, the robot cleaner <NUM> may automatically dock with the maintenance station <NUM>, to automatically discharge dust collected in the first dust box <NUM>.

The various sensors <NUM>, which are mounted to the body <NUM>, may be used to sense obstacles. As these sensors <NUM>, a contact sensor, a proximity sensor, etc. may be used. For example, a bumper <NUM>, which is arranged at a front portion of the body <NUM>, to be directed to a front direction F of the body <NUM>, may be used to sense a front obstacle such as a wall. It may also be possible to sense a front obstacle, using an infrared sensor (or an ultrasonic sensor).

An infrared sensor <NUM> (or an ultrasonic sensor), which is arranged on the bottom of the body <NUM>, may be used to sense a condition of the floor, for example, condition of steps. A plurality of infrared sensors <NUM> may be installed on the bottom of the body <NUM> along an arc-shaped peripheral portion of the body <NUM>.

Various sensors other than the above-described sensors may also be installed on the body <NUM>, to transfer various conditions of the robot cleaner <NUM> to the controller.

The controller receives signals from the various sensors <NUM>, and controls the driving unit <NUM> and cleaning unit <NUM>, based on the received signals, thereby more efficiently controlling the robot cleaner <NUM>.

<FIG> is a perspective view illustrating a top perspective view illustrating a configuration of the maintenance station according to an exemplary embodiment of the present disclosure. <FIG> is a top perspective view illustrating a configuration of the maintenance station according to another exemplary embodiment of the present disclosure. <FIG> is a top perspective view illustrating a configuration of the maintenance station according to another exemplary embodiment of the present disclosure. <FIG> is a top perspective view illustrating a configuration of the maintenance station according to another exemplary embodiment of the present disclosure. <FIG> is a sectional view illustrating a configuration of the maintenance station according to another exemplary embodiment of the present disclosure. <FIG> is a plan view illustrating a duct included in the maintenance station according to the embodiment of <FIG>. <FIG> is a plan view illustrating the maintenance station according to the embodiment of <FIG>.

As shown in <FIG> , the robot cleaner <NUM> may dock with the maintenance station <NUM> in various situations. For example, there may be various situations such as a situation in which the battery (not shown) of the robot cleaner <NUM> needs to be charged, a situation in which the robot cleaner <NUM> has performed a cleaning task for a predetermined time, a situation in which the robot cleaner <NUM> has completed a cleaning task, and a situation in which the first dust box <NUM> of the robot cleaner <NUM> is completely filled with dust.

The maintenance station <NUM> may include a housing <NUM>, a docking guide unit <NUM>, a charging unit <NUM>, a dust removal unit <NUM>, and a controller (not shown).

A platform <NUM> may be provided at the housing <NUM>. The platform <NUM> may support the robot cleaner <NUM> while the robot cleaner <NUM> docks with the maintenance station <NUM>.

The platform <NUM> has an inclined structure to allow the robot cleaner <NUM> to easily ascend along or descend from the platform <NUM>. A caster guide 63a may be formed at the platform <NUM>, to guide the caster <NUM> of the robot cleaner <NUM>. Driving wheel guides 63b and 63c may also be formed at the platform <NUM>, to guide the left and right driving wheels 31a and 31b of the robot cleaner <NUM>. The caster guide 63a and driving wheel guides 63b and 63c may be formed to be recessed, as compared to portions of the platform <NUM> therearound.

A second opening 62a may be formed through the platform <NUM>. The second opening 62a of the platform <NUM> may be arranged at a position where the second opening 62a may communicate with the first opening 21a of the robot cleaner <NUM>. In accordance with this arrangement, dust discharged through the first opening 21a of the robot cleaner <NUM> may be introduced into the second opening 62a of the platform <NUM>. The dust introduced into the second opening 62a of the platform <NUM> may be collected in a second dust box <NUM> included in the maintenance station <NUM>.

The second dust box <NUM> of the maintenance station <NUM> is different from the first dust box <NUM> of the robot cleaner <NUM>. The first dust box <NUM> of the robot cleaner <NUM> stores dust collected by the robot cleaner <NUM> during movement of the robot cleaner <NUM>. The second dust box <NUM> of the maintenance station <NUM> collects and stores dust discharged from the first dust box <NUM>. In this regard, the second dust box <NUM> of the maintenance station 60n may have a greater capacity than the first dust box <NUM> of the robot cleaner <NUM>.

The dust sensing unit <NUM> may also be installed within the second dust box <NUM>, in order to sense the amount of dust in the second dust box <NUM>.

In this case, the dust sensing unit <NUM> may include a light emitting sensor 44a and a light receiving sensor 44b. When the light receiving sensor 44b cannot receive a signal transmitted from the light emitting sensor 44a, the controller may determine that the amount of dust in the second dust box <NUM> corresponds to a predetermined amount or more.

The second opening 62a of the platform <NUM> may have an open structure, as shown in <FIG>. That is, the second opening 62a of the platform <NUM> may always be open without being covered by a separate cover.

The platform <NUM> may be formed to be inclined at a predetermined angle θ or more ( <FIG> ). When the robot cleaner <NUM> moves on the platform <NUM> inclined at the predetermined angle θ or more, the front portion of the robot cleaner <NUM> may be slightly lifted because the weight of the robot cleaner <NUM> is rearwardly biased. As a result, the caster <NUM> of the robot cleaner <NUM> may pass the second opening 62a of the platform <NUM> without falling into the second opening 62a. Meanwhile, a cover <NUM> may be installed at the second opening 62a of the platform <NUM>, to slidably move along the second opening 62a, as shown in <FIG>. When the robot cleaner <NUM> is completely docked, the cover <NUM> may be opened, to allow the robot cleaner <NUM> to discharge dust through the second opening 62a of the platform <NUM>. On the other hand, when the docked state of the robot cleaner <NUM> is released, the cover <NUM> may be closed to close the second opening 62a of the platform <NUM>.

The cover <NUM> may also function as a bridge upon which the caster <NUM> of the robot cleaner <NUM> will move. The cover <NUM> may be opened or closed in linkage with docking of the robot cleaner <NUM>. That is, the cover <NUM> may be opened while or before the caster <NUM> passes the cover <NUM> during docking of the robot cleaner <NUM>. The cover <NUM> may be closed while or after the caster <NUM> passes the cover <NUM> during docking release of the robot cleaner <NUM>. It may also be possible to open or close the cover <NUM>, using a separate device.

On the other hand, as shown in <FIG> , a cover <NUM> may be installed at the second opening 62a of the platform <NUM>, to slidably move along the second opening 62a. Of course, the cover <NUM> may be installed only at a central portion of the second opening 62a of the platform <NUM> in the case of <FIG> , different from the case of <FIG>. This structure is adapted to allow the caster <NUM> of the robot cleaner <NUM> to pass the second opening 62a of the platform <NUM>. The opening/closing operation of the cover <NUM> may be achieved in the same manner as described above.

On the other hand, as shown in <FIG> , a bridge <NUM> may be installed at the second opening 62a of the platform <NUM>. The bridge <NUM> may be installed only at a central portion of the second opening 62a of the platform <NUM>, to achieve a bridge function allowing the caster <NUM> of the robot cleaner <NUM> to pass the bridge <NUM>.

As shown in <FIG> , the bridge <NUM> may be installed at the second opening 62a of the platform <NUM> to move upward and downward. That is, when the robot cleaner <NUM> enters the platform <NUM>, the bridge 67a moves upward to allow the caster <NUM> of the robot cleaner <NUM> to move thereon. When the docking of the robot cleaner <NUM> is completed, the bridge 67b moves downward to allow the second opening 62a of the platform <NUM> to secure an increased opening area.

The docking guide unit <NUM> may be installed at an upper portion of the housing <NUM>. The docking guide unit <NUM> may include a plurality of sensors <NUM>. The sensors <NUM> may define a docking guide region and a docking region, to accurately guide the robot cleaner <NUM> to dock with the maintenance station <NUM>.

The charging unit <NUM> may be installed at the platform <NUM>. The charging unit <NUM> may include a plurality of connecting terminals 81a and 81b. The connecting terminals 81a and 81b may correspond to a plurality of connecting terminals 23a and 23b provided at the robot cleaner <NUM>. When docking of the robot cleaner <NUM> is completed, current may be supplied to the plural connecting terminals 23a and 23b of the robot cleaner <NUM> via the plural connecting terminals 81a and 81b of the maintenance station <NUM>.

The charging unit <NUM> may supply current after determining whether or not the plural connecting terminals 23a and 23b of the robot cleaner <NUM> are connected to the charging unit <NUM>. That is, when the charging unit <NUM> is connected to an element other than the plural connecting terminals 23a and 23b, the charging unit <NUM> interrupts supply of current, to avoid occurrence of an accident.

The dust removal unit <NUM> may be installed at the housing <NUM>. The dust removal unit <NUM> may discharge dust stored in the first dust box <NUM> of the robot cleaner <NUM> into the second dust box <NUM> of the maintenance station <NUM>, to empty the first dust box <NUM>. Thus, the dust removal unit <NUM> may maintain desired cleaning performance of the robot cleaner <NUM>.

The dust removal unit <NUM> may include a pump unit <NUM>, a suction duct <NUM>, and a discharge duct <NUM>, in addition to the second dust box <NUM>. The dust removal unit <NUM> functions to force a flow of air discharged from the discharge duct <NUM> to be sucked back into the suction duct <NUM>. Using such a circulating air flow, the dust removal unit <NUM> removes dust stored in the first dust box <NUM> of the robot cleaner <NUM>.

The pump unit <NUM> is a device to suck/discharge air. The pump unit <NUM> may include a fan and a motor.

The suction duct <NUM> may be installed at a suction side of the pump unit <NUM>. The suction duct <NUM> may include a suction port 92a, which may form a portion of the second opening 62a. Alternatively, the suction port 92a may be separate from the second opening 62a. In this case, the suction duct 92a may be arranged at a position adjacent to the second opening 62a.

The suction port 92a may extend in a longitudinal direction of the second opening 62a, to occupy a portion of the second opening 62a, except for a portion of the second opening 62a occupied by discharge ports 93a and 93b of the discharge duct <NUM>.

The discharge duct <NUM> may be installed at a discharge side of the pump unit <NUM>. The discharge duct <NUM> may be divided into two portions, which form the two discharge ports 93a and 93b. The discharge ports 93a and 93b may form portions of the second opening 62a. Alternatively, the discharge ports 93a and 93b may be separate from the second opening 62a. In this case, the discharge ports 93a and 93b may be arranged at positions adjacent to the second opening 62a.

The discharge ports 93a and 93b may be formed at longitudinal ends of the second opening 62a, namely, opposite side regions of the second opening 62a, respectively.

The suction port 92a of the suction duct <NUM> may have a larger cross-sectional area than the sum of the cross-sectional areas of the discharge ports 93a and 93b of the discharge duct <NUM>. Hereinafter, the sum of the cross-sectional areas of the discharge ports 93a and 93b of the discharge duct <NUM> will be simply referred to as "the cross-sectional area of the discharge ports 93a and 93b". The cross-sectional area ratio between the suction port 92a of the suction duct <NUM> and the discharge ports 93a and 93b of the discharge duct may be <NUM>:<NUM>. Of course, the cross-sectional area ratio of the suction port 92a of the suction duct <NUM> to the discharge ports 93a and 93b of the discharge duct may be smaller than the above-described ratio, for example, may be <NUM>:<NUM>, <NUM>:<NUM>, or <NUM>:<NUM>. Even when the cross-sectional area ratio is slightly reduced, as described above, it falls within the technical scope of the present disclosure.

Accordingly, the air flow velocity at the discharge ports 93a and 93b of the discharge duct <NUM> may be higher than the air flow velocity at the suction port 92a of the suction duct <NUM> because there is a cross-sectional area difference between the suction port 92a and the discharge ports 93a and 93b under the condition that the suction flow rate and discharge flow rate of the pump unit <NUM> are substantially equal. By virtue of this flow velocity difference, it may be possible to prevent air emerging from the discharge ports 93a and 93b from being sucked into the suction port 92a. That is, air emerging from the discharge ports 93a and 93b may be injected into the first dust box <NUM> without being directly sucked into the suction port 92a by a suction force at the suction port 92a, because the air flow velocity of the discharged air is very high. Thus, air injected into the first dust box <NUM> may emerge from the first dust box <NUM> after circulating through the first dust box <NUM>, and may then enter the suction port 92a.

<FIG> is a sectional view illustrating a docking state of the robot cleaner and maintenance station.

As shown in <FIG> , when the robot cleaner <NUM> docks with the maintenance station <NUM>, the first opening 21a of the robot cleaner <NUM> may communicate with the second opening 62a of the maintenance station <NUM>.

When docking is achieved, the suction port 92a of the suction duct <NUM> may be arranged adjacent to the first opening 21a of the robot cleaner <NUM> while extending in the longitudinal direction of the first opening 21a. Also, the discharge ports 93a and 93b of the discharge duct <NUM> may be arranged adjacent to the first opening 21a of the robot cleaner <NUM> at the longitudinal ends of the first opening 21a of the robot cleaner <NUM>, namely, the opposite side regions of the first opening 21a, respectively.

In accordance with the above-described configuration, air circulated (returned) by the dust removing device <NUM> during the docking operation may form a closed loop. That is, air discharged from the pump unit <NUM> rapidly emerges from the discharge ports 93a and 93b of the discharge duct <NUM>, and then enters the first dust box <NUM> of the robot cleaner <NUM> after passing through the opposite side regions of the first opening 21a. The air introduced into the first dust box <NUM> of the robot cleaner <NUM> is discharged through the central region of the first opening 21a, to be introduced into the second dust box <NUM> of the maintenance station <NUM> through the suction port 92a of the suction duct <NUM>. Thereafter, the air is again sucked into the pump unit <NUM>.

<FIG> is a view illustrating a configuration of the brush cleaning member according to an exemplary embodiment of the present disclosure. <FIG> is a view illustrating a configuration of the brush cleaning member according to another exemplary embodiment of the present disclosure. <FIG> is a view illustrating a configuration of the brush cleaning member according to another exemplary embodiment of the present disclosure.

As shown in <FIG> , the maintenance station <NUM> may include a brush cleaning member 95a to clean the brush unit <NUM> of the robot cleaner <NUM>. The brush cleaning member 95a of the maintenance station <NUM> is different from the brush cleaning member <NUM> c of the robot cleaner <NUM>.

The brush cleaning member 95a of the maintenance station <NUM> may be arranged adjacent to the second opening 62a. The brush cleaning member 95a of the maintenance station <NUM> may be protruded from the bottom of the housing <NUM> toward the second opening 62a. The brush cleaning member 95a may include a plurality of brush cleaning members arranged in a longitudinal direction of the second opening 62a.

In a docking state, the brush cleaning member 95a of the maintenance station <NUM> may be in contact with the brush unit <NUM> of the robot cleaner <NUM>. The brush cleaning member 95a of the maintenance station <NUM> may remove foreign matter such as hairs wound around the brush unit <NUM> of the robot cleaner <NUM>. In particular, the foreign matter removed by the brush cleaning member 95a of the maintenance station <NUM> may be introduced into the second dust box <NUM> by the suction force of the pump unit <NUM> because the brush cleaning member 95a of the maintenance station <NUM> may be arranged at the suction duct <NUM>.

In accordance with another embodiment of the present disclosure, the brush cleaning member 95b of the maintenance station <NUM> may be arranged to be slidably movable in the longitudinal direction of the second opening 62a, as shown in <FIG>. The brush cleaning member 95b of the maintenance station <NUM> may remove foreign matter wound around the brush unit <NUM> of the robot cleaner <NUM> while sliding.

In accordance with another embodiment of the present disclosure, the brush cleaning member 95c of the maintenance station <NUM> may be installed to be upwardly and downwardly movable, as shown in <FIG>. The brush cleaning member 95c may move upward when the docking of the robot cleaner is completed, so that the brush cleaning member 95c comes into contact with the brush unit <NUM> of the robot cleaner <NUM>. On the other hand, when the docking of the robot cleaner is released, the brush cleaning member 95c may move downward. Meanwhile, the upward and downward movement of the brush cleaning member 95c may be carried out in linkage with docking of the robot cleaner <NUM>.

The brush unit <NUM> of the robot cleaner <NUM> may more effectively move dust in cooperation with the dust removal unit <NUM>. When the dust removal unit <NUM> circulates air, the brush unit <NUM> of the robot cleaner <NUM> may rotate in a clockwise direction in <FIG>. In this case, the brush unit <NUM> of the robot cleaner <NUM> may assist introduction of air into the first dust box <NUM> of the robot cleaner <NUM>. Furthermore, the brush unit <NUM> may assist introduction of air emerging from the first dust box <NUM> of the robot cleaner <NUM> into the suction port 92a of the suction duct <NUM>.

The brush unit <NUM> of the robot cleaner may rotate at various speeds, to more effectively move dust. For example, when the dust removal unit <NUM> circulates air, the brush unit <NUM> of the robot cleaner <NUM> may slowly rotate in an early stage, and may then rapidly rotate. Here, the "early stage" means a certain period of time. This period may be set to be a sufficient time to allow light dust such as hairs to be discharged. As the brush unit <NUM> of the robot cleaner <NUM> rotates slowly in the early stage, foreign matter such as relatively-light hairs may be easily moved to the suction port 92a of the suction duct <NUM> by the suction force of the dust removal unit <NUM>. As the brush unit <NUM> of the robot cleaner <NUM> then rotates rapidly, relatively-heavy dust may be easily moved to the suction port 92a of the suction duct <NUM> by virtue of the rotating force of the brush unit <NUM>.

The brush unit <NUM> of the robot cleaner <NUM> may remove foreign matter wound around the brush unit <NUM> while changing the rotation direction thereof at least one time. Dust stored in the first dust box <NUM> of the robot cleaner <NUM> may be wound around the brush unit <NUM> of the robot cleaner <NUM> because it is discharged through the first opening 21a of the robot cleaner <NUM> after passing the brush unit <NUM> of the robot cleaner <NUM>. At this time, it may be possible to unwind the foreign matter wound around the brush unit <NUM> of the robot cleaner <NUM> by changing the rotation direction of the brush unit <NUM> of the robot cleaner <NUM>. The unwound foreign matter is moved to the suction port 92a of the suction duct <NUM>, and is then stored in the second dust box <NUM> of the maintenance station <NUM>. Subsequently, the brush unit <NUM> of the robot cleaner <NUM> may again change the rotation direction, so as to rotate in the original direction. The brush unit <NUM> of the robot cleaner <NUM> may repeat the change of the rotation direction several times.

Hereinafter, operation of the cleaning system according to an exemplary embodiment of the present disclosure will be described.

As shown in <FIG> , the robot cleaner <NUM> may sense a signal from the docking guide unit <NUM>, to accurately dock with the maintenance station <NUM> in accordance with the sensed signal. Docking is initiated as the body <NUM> enters the platform <NUM>, starting from the front portion of the body <NUM>. Docking is completed at a position where the first opening 231a of the robot cleaner <NUM> communicates with the second opening 62a of the maintenance station <NUM>.

Upon completion of docking, the dust removal unit <NUM> may discharge dust stored in the robot cleaner <NUM> to the maintenance station <NUM>. In detail, the pump unit <NUM> may discharge air at a high flow velocity through the discharge ports 93a and 93b of the discharge duct <NUM>. The air emerging from the discharge ports 93a and 93b may be introduced into the first dust box <NUM> after passing through the first opening 21a of the robot cleaner <NUM>. The air introduced into the first dust box <NUM> of the robot cleaner <NUM> may completely circulate the entire space of the first dust box <NUM> without forming a dead space in the first dust box <NUM>. In particular, air emerging from the discharge ports 93a and 93b may completely stir dust, starting from the side portion of the first dust box <NUM>, because the discharge ports 93a and 93b are arranged at the opposite side regions of the first opening 20a of the robot cleaner <NUM> as viewed in the longitudinal direction of the first opening 20a. Subsequently, the dust stored in the first dust box <NUM> may be suspended in the air introduced into the first dust box <NUM>, and may then be discharged through the first opening 21a, along with the air introduced into the first dust box <NUM>. The suction port 92a of the suction duct <NUM> applies a suction force to the first opening 21a of the robot cleaner <NUM>, thereby causing dust emerging from the first dust box <NUM> of the robot cleaner <NUM> to be sucked. The dust introduced into the suction port 92a of the suction duct <NUM> may be stored in the second dust box <NUM> of the maintenance station <NUM>. Air is again sucked into the pump unit <NUM> via a filter 94a.

Thus, the air discharged from the pump unit <NUM> may be reintroduced into the pump unit <NUM> after sequentially passing through the discharge duct <NUM>, the first opening 21a of the robot cleaner <NUM>, the first dust box <NUM> of the robot cleaner <NUM>, the first opening 21a of the robot cleaner <NUM>, the suction duct <NUM>, and the second dust box <NUM> of the maintenance station <NUM>. As air circulates (returns) as described above, it may be possible to maximally prevent outward discharge of air. Accordingly, it may be possible to reduce the performance of the filter 94a. Furthermore, it may be possible to achieve suction/discharge of air, using a single pump unit as the pump unit <NUM>.

Dust emerging from the first dust box <NUM> of the robot cleaner <NUM> may be moved to a large central region of the first opening 21a of the robot cleaner <NUM> and a large central region of the second opening 62a of the maintenance station <NUM> because the air emerging from the discharge ports 93a and 93b of the discharge duct <NUM> may be discharged through the opposite side regions of the first opening 21a of the robot cleaner <NUM> and second opening 62a of the maintenance station <NUM> as viewed in the longitudinal direction of the first and second openings 21a and 62a, and the air sucked at the suction port 92a of the suction duct <NUM> may be sucked through the large regions of the first opening 21a of the robot cleaner <NUM> and second opening 62a of the maintenance station <NUM> as viewed in the longitudinal direction of the first and second openings 21a and 62a. The arrangements of the suction port 92a and discharge ports 93a and 93b may prevent dust emerging from the first dust box <NUM> of the robot cleaner <NUM> from moving through the opposite side regions, and thus may prevent the dust from being outwardly discharged. The positions of the suction port 92a and discharge ports 93a and 93b with regard to the first opening 21a of the robot cleaner <NUM> and the second opening 62a of the maintenance station <NUM> may provide a certain sealing effect between the robot cleaner <NUM> and the maintenance station <NUM>.

Meanwhile, the brush unit <NUM> may be controlled to rotate slowly in an early stage, and then to rotate rapidly while the dust removal unit <NUM> circulates air, in order to assist the dust removal unit <NUM>. In detail, the brush unit <NUM> assists, in the early stage, the dust removal unit <NUM> to rapidly suck light dust such as hairs while rotating slowly. Subsequently, the brush unit <NUM> assists the dust removal unit <NUM> to suck relatively-heavy dust while rotating rapidly.

Furthermore, the brush unit <NUM> may be controlled to change the rotation direction thereof at least one time while the dust removal unit <NUM> circulates air, in order to assist the dust removal unit <NUM>. In detail, foreign matter such as hairs may be wound around the brush unit <NUM>. The wound foreign matter such as hairs may be unwound as the rotation direction of the brush unit <NUM> is changed. In this case, the dust removal unit <NUM> may suck the foreign matter such as hairs off of the brush unit <NUM>.

Meanwhile, the brush cleaning member <NUM> of the maintenance station <NUM> may remove foreign mater such as hairs wound around the brush unit <NUM> of the robot cleaner <NUM>. Foreign matter wound around the brush unit <NUM> of the robot cleaner <NUM> during rotation of the brush unit <NUM> comes into contact with the brush cleaning member <NUM> of the maintenance station <NUM>, so that the foreign matter may be removed from the brush unit <NUM> by the brush cleaning member <NUM> of the maintenance station <NUM>. The removed foreign matter may be collected in the second dust box <NUM> by the suction force of the dust removal unit <NUM>.

<FIG> is a view schematically illustrating a cleaning system according to another exemplary embodiment of the present disclosure. <FIG> is a perspective view illustrating a suction/discharge dual tube. <FIG> is a view illustrating flow of air in the cleaning system according to the embodiment shown in <FIG>.

As shown in <FIG> , the cleaning system <NUM> may discharge dust stored in a first dust box <NUM> included in a robot cleaner <NUM> to a second dust box <NUM> included in a maintenance station <NUM>. The following description will be given only in conjunction with matters different from those of the previous embodiments.

The maintenance station <NUM> may include a suction/discharge dual tube <NUM>, to which a suction air flow and a discharge air flow are applied. Here, the "suction air flow" is an air flow emerging from the first dust box <NUM> of the robot cleaner <NUM>, whereas the "discharge air flow" is an air flow introduced into the first dust box <NUM> of the robot cleaner <NUM>. When docking is carried out, the first dust box <NUM> of the robot cleaner <NUM> may be coupled with the suction/discharge dual tube <NUM> of the maintenance station <NUM> via a communicating member <NUM>.

The suction/discharge dual tube <NUM> may have a concentric dual tube structure. For example, the suction/discharge dual tube <NUM> may include a discharge tube <NUM> arranged at a central portion of the suction/discharge dual tube <NUM>, and a suction tube <NUM> surrounding an outer peripheral surface of the discharge tube <NUM>.

On the other hand, the suction/discharge dual tube may have a parallel dual tube structure in accordance with another embodiment. For example, the suction/discharge dual tube may include suction and discharge tubes arranged in parallel in a longitudinal direction or in a lateral direction.

The maintenance station <NUM> may include a dust removal unit <NUM>. The dust removal unit <NUM> may include a pump unit <NUM>, a suction duct <NUM> installed at a suction side of the pump unit <NUM>, and connected to the suction tube <NUM> of the suction/discharge dual tube <NUM>, a discharge duct <NUM> installed at a discharge side of the pump unit <NUM>, and connected to the discharge tube <NUM> of the suction/discharge dual tube <NUM>, and a second dust box <NUM>.

When the robot cleaner <NUM> docks with the maintenance station <NUM>, air discharged from the pump unit <NUM> may be introduced into the first dust box <NUM> of the robot cleaner <NUM> after entering the discharge tube <NUM> of the suction/discharge dual tube <NUM> via the discharge duct <NUM>. Thereafter, the air introduced into the first dust box <NUM> may pass through the suction duct <NUM> after being sucked into the suction tube <NUM> of the suction/discharge dual tube <NUM>, along with dust stored in the first dust box <NUM>. The dust passing through the suction duct <NUM> may be stored in the second dust box <NUM>, and may then be sucked into the pump unit <NUM> again.

Thus, the air discharged from the pump unit <NUM> may be reintroduced into the pump unit <NUM> after sequentially passing through the discharge duct <NUM>, the discharge tube <NUM> of the suction/discharge dual tube <NUM>, the first dust box <NUM> of the robot cleaner <NUM>, the suction tube <NUM> of the suction/discharge dual tube <NUM>, the suction duct <NUM>, and the second dust box <NUM> of the maintenance station <NUM>.

<FIG> is a view schematically illustrating a cleaning system according to another embodiment of the present disclosure.

The first dust box <NUM> of the robot cleaner <NUM> may include an inlet communicating with a first opening 321a included in the robot cleaner <NUM>, and a communicating member <NUM> to directly communicate with the maintenance station <NUM>.

The maintenance station <NUM> may include a dust removal unit <NUM>. The dust removal unit <NUM> may include a pump unit <NUM>, a suction duct <NUM> installed at a suction side of the pump unit <NUM>, and a discharge duct <NUM> installed at a discharge side of the pump unit <NUM>.

When the robot cleaner <NUM> docks with the maintenance station <NUM>, the first opening 321a of the robot cleaner <NUM> may be connected to the suction duct <NUM> of the maintenance station <NUM>, and the communicating member <NUM> of the first dust box <NUM> in the robot cleaner <NUM> may be connected to the discharge duct <NUM> of the maintenance station <NUM>.

Air discharged from the pump unit <NUM> may be introduced into the first dust box <NUM> of the robot cleaner <NUM> via the discharge duct <NUM>. The air introduced into the first dust box <NUM> of the robot cleaner <NUM> may be moved to the suction duct <NUM> after passing through the inlet <NUM>' of the first dust box <NUM> and the first opening 321a of the robot cleaner <NUM>, along with dust stored in the first dust box <NUM>. The dust moved to the suction duct <NUM> is stored in the second dust box <NUM> of the maintenance station <NUM>, whereas the air may be sucked into the pump unit <NUM> again.

Thus, the air discharged from the pump unit <NUM> may be reintroduced into the pump unit <NUM> after sequentially passing through the discharge duct <NUM>, communicating member <NUM> of the first dust box <NUM>, the first dust box <NUM> of the robot cleaner <NUM>, the inlet <NUM>' of the first dust box <NUM>, the suction duct <NUM>, and the second dust box <NUM> of the maintenance station <NUM>.

When the robot cleaner <NUM> docks with the maintenance station <NUM>, a first opening 421a of the robot cleaner <NUM> may be connected to a discharge duct <NUM> of the maintenance station <NUM>, and a communicating member <NUM> included in the first dust box <NUM> of the robot cleaner <NUM> may be connected to a suction duct <NUM> of the maintenance station <NUM>.

Air discharged from the pump unit <NUM> may be introduced into the first dust box <NUM> of the robot cleaner <NUM> via the discharge duct <NUM>, the first opening 421a of the robot cleaner <NUM>, and an inlet <NUM>' of the first dust box <NUM>. The air introduced into the first dust box <NUM> of the robot cleaner <NUM> may be moved to the suction duct <NUM> after passing through the communicating member <NUM> of the first dust box <NUM>, along with dust stored in the first dust box <NUM>. The dust moved to the suction duct <NUM> is stored in the second dust box <NUM> of the maintenance station <NUM>, whereas the air may be sucked into the pump unit <NUM> again.

Thus, the air discharged from the pump unit <NUM> may be reintroduced into the pump unit <NUM> after sequentially passing through the discharge duct <NUM>, the inlet <NUM>' of the first dust box <NUM>, the first dust box <NUM> of the robot cleaner <NUM>, the communicating member <NUM> of the first dust box <NUM>, the suction duct <NUM>, and the second dust box <NUM> of the maintenance station <NUM>.

<FIG> is a top perspective view illustrating a configuration of the maintenance station according to another exemplary embodiment of the present disclosure. <FIG> is an exploded perspective view illustrating a configuration of the maintenance station according to the illustrated embodiment of the present disclosure. <FIG> is a plan view illustrating a duct included in the maintenance station according to the illustrated embodiment of the present disclosure. <FIG> is a sectional view illustrating a flow of air discharged through a second opening during a docking operation. <FIG> is a sectional view illustrating a flow of air sucked through the second opening during the docking operation. <FIG> is a top perspective view illustrating a port assembly according to another exemplary embodiment of the present disclosure. <FIG> is a bottom perspective view illustrating the port assembly according to the illustrated embodiment of the present disclosure.

Referring to <FIG> , a cleaning system <NUM> is illustrated. The cleaning system <NUM> has the same basic structure as the above-described cleaning system <NUM>. Accordingly, the following description will be given mainly in conjunction with portions of the cleaning system <NUM> different from the cleaning system <NUM>, and no description will be given of the same portions of the cleaning system <NUM> as the cleaning system <NUM>, if possible.

A platform <NUM> may be provided at the housing <NUM>. A second opening 562a may be formed at the platform <NUM>. The second opening 562a of the platform <NUM> is arranged at a position where the second opening 562a may communicate with a first opening 521a of the robot cleaner <NUM>. Dust discharged through the first opening 521a of the robot cleaner <NUM> may be introduced into the second opening 562a of the platform <NUM>, and is then stored in a second dust box <NUM> of the maintenance station <NUM>. In this case, the second opening 562a of the platform <NUM> may be larger than the first opening 521a of the robot cleaner <NUM>.

The dust removal unit <NUM> may include a pump unit <NUM>, a suction duct <NUM>, a first discharge duct 593a, a second discharge duct 593b, a port assembly <NUM>, and a suction/discharge dual tube <NUM>, in addition to the second dust box <NUM>. The dust removal unit <NUM> functions to force air discharged from the first and second discharge ducts 593a and 593b to be sucked back into the suction duct <NUM>. Using such a circulating air flow, the dust removal unit <NUM> removes dust stored in the first dust box <NUM> of the robot cleaner <NUM>.

The suction duct <NUM> may be installed at a suction side of the pump unit <NUM>. The first and second discharge ducts 593a and 593b may be installed at a discharge side of the pump unit <NUM>. The port assembly <NUM> may be separably mounted to the second opening 562a. The port assembly <NUM> communicates with the suction duct <NUM>, first discharge duct 593a, and second discharge duct 593b.

The port assembly <NUM> may include a suction port forming member <NUM>, a first discharge port forming member <NUM>, a second discharge port forming member <NUM>, a third discharge port forming member <NUM>, a fourth discharge port forming member <NUM>, and a brush cleaning member <NUM>.

The suction port forming member <NUM> divides the suction duct <NUM> into two portions, which form first and second suction ports 592a and 592b, respectively. First spacers 610a and 610b are formed at a lower surface of the suction port forming member <NUM>. The first spacers 610a and 610b function to space the suction port forming member <NUM> from the bottom of the housing <NUM>.

Air or dust introduced into the first suction port 592a flows toward the suction duct <NUM> along an upper surface of the suction port forming member <NUM>. Air or dust introduced into the second suction port 592b flows toward the suction duct <NUM> along a lower surface of the suction port forming member <NUM>. The dust is subsequently stored in the second dust box <NUM> of the maintenance station <NUM>.

The first discharge port forming member <NUM> and second discharge port forming member <NUM> divide the first discharge duct 593a, into two portions, which form first and second discharge ports 593a' and 593a", respectively. On the other hand, the third discharge port forming member <NUM> and fourth discharge port forming member <NUM> divide the second discharge duct 593b, into two portions, which form third and fourth discharge ports 593b' and 593b", respectively.

Air discharged through the first discharge port 593a' and third discharge port 593b' is fed to a large dust box 543a of the robot cleaner <NUM>, whereas air discharged through the second discharge port 593a" and fourth discharge port 593b" is fed to a small dust box 543b of the robot cleaner <NUM>. The first discharge port 593a' and third discharge port 593b' directly face the large dust box 543a. Accordingly, air discharged through the first discharge port 593a' and third discharge port 593b' is fed to the large dust box 543a while passing through the brush unit <NUM> at high flow rate.

However, the second discharge port 593a" and fourth discharge port 593b" do not directly fact the small dust box 543b. For this reason, air discharged through the second discharge port 593a" and fourth discharge port 593b" is guided by a brush drum 540a, to be fed to the small dust box 543b. When the brush unit <NUM> rotates in a counterclockwise direction in <FIG> , air discharged through the second discharge port 593a" and fourth discharge port 593b" may be more smoothly fed to the small dust box 543b.

The first discharge port 593a' and third discharge port 593b' are arranged at opposite longitudinal (or lateral) ends of the second opening 562a, namely, opposite side regions of the second opening 562a, respectively. Also, the second discharge port 593a" and fourth discharge port 593b" are arranged at opposite longitudinal (or lateral) ends of the second opening 562a, namely, opposite side regions of the second opening 562a, respectively. On the other hand, the first discharge port 593a' and second discharge port 593a" are arranged at opposite ends of the second opening 562a in a width (forward or backward) direction in one side region of the second opening 562a, respectively. Also, the third discharge port 593b' and fourth discharge port 593b" are arranged at opposite ends of the second opening 562a in the width (forward or backward) direction in the other side region of the second opening 562a, respectively. Thus, the first discharge port 593a' to fourth discharge port 593b" are arranged at respective corner regions of the second opening 562a.

Meanwhile, second spacers 622a and 624a are formed at side walls of the second discharge port forming member <NUM> and fourth discharge port forming member <NUM>, respectively. The second spacers 622a and 624a function to prevent the port assembly <NUM> from being biased toward one side of the second opening 562a.

Thus, the second suction port 592b may be formed to have a structure surrounding the first suction port 592a, first discharge port 593a', second discharge port 593a", third discharge port 593b', and fourth discharge port 593b". The area occupied by the first suction port 592a and the first to fourth discharge ports 593a', 593a", 593b', and 593b" corresponds to the area of the first opening 521a of the robot cleaner <NUM>. The second suction port 592b may suck dust dispersed outside the first opening 521a of the robot cleaner <NUM> because it is arranged outside the first opening 521a of the robot cleaner <NUM>.

A cover <NUM> formed with a plurality of through holes 640a may be mounted to the second suction port 592a. In this case, dust dispersed outside the first opening 521a of the robot cleaner <NUM> may be sucked into the second suction port 592b through the through holes 640a. Normally, the cover <NUM> prevents foreign matter having a large size from entering the second suction port 592a, thereby preventing the suction passage from becoming clogged.

The brush cleaning member <NUM> is formed at the suction port forming member <NUM>, to be protruded from the suction port forming member <NUM>, and thus to come into contact with brushes 541b of the brush unit <NUM>. A plurality of brush cleaning members <NUM> may be installed to be arranged in a longitudinal direction of the suction port forming member <NUM>, as in the illustrated case. In the illustrated case, the brush cleaning members <NUM> are arranged in two rows in the longitudinal direction of the suction port forming member <NUM>. In another embodiment, a plurality of brush cleaning members <NUM> may be arranged in one row, two rows, or more.

The brush cleaning member <NUM> may include a guide <NUM> and a hook <NUM>.

The guide <NUM> extends inclinedly with respect to a rotation direction of the brush unit <NUM>. The hook <NUM> is protruded from a side surface of an end of the guide <NUM>. When the brush unit <NUM> rotates, the brushes 541b, which are made of an elastic material, are inclined in the inclined direction of the guide <NUM> while coming into contact with the guide <NUM>. Accordingly, foreign matter, which may be hairs wound around the brushes 541b, may be caught by the hook <NUM> which, in turn, separates the foreign matter from the brushes 541b.

Meanwhile, in another embodiment, a plurality of guides <NUM> may be arranged in a longitudinal direction of the suction port forming member <NUM>, and a plurality of hooks <NUM> may be protruded from side surfaces of guides <NUM>, respectively. The guides <NUM>, which are arranged in the longitudinal direction of the suction port forming member <NUM>, may be laterally symmetrically arranged.

A plurality of suction/discharge dual tubes <NUM> may be provided at the platform <NUM>. The plural suction/discharge dual tubes <NUM> are arranged at positions corresponding to a plurality of infrared sensors <NUM> installed on a bottom of the robot cleaner <NUM>. The concrete shape of each suction/discharge dual tubes <NUM> may be referred to the description given with reference to <FIG>.

Each suction/discharge dual tube <NUM> generates a suction air flow and a discharge air flow. Here, the suction air flow is an air flow introduced into the housing <NUM> through a suction tube <NUM> communicating with the suction duct <NUM>, whereas the discharge air flow is an air flow outwardly discharged from the housing <NUM> through a discharge tube <NUM> communicating with the first discharge duct 593a or second discharge duct 593b.

The infrared sensors <NUM> of the robot cleaner <NUM> may be cleaned by air flowing through the corresponding suction/discharge dual tubes <NUM>, respectively. That is, air is blown to each infrared sensor <NUM> of the robot cleaner <NUM> through the discharge tube <NUM> of the corresponding suction/discharge dual tube <NUM>, to remove dust from the infrared sensor <NUM>, and the removed dust is then sucked through the suction tube <NUM> of the corresponding suction/discharge dual tube <NUM>. The dust introduced into the suction tube <NUM> is collected in the second dust box <NUM> of the maintenance station <NUM>.

Thus, dust attached to each infrared sensor <NUM> is removed, so that desired sensing performance may be maintained. Since the dust removed from the infrared sensor <NUM> is sucked back without being dispersed, the surroundings of the station <NUM> may be kept clean.

As apparent from the above description, the cleaning system according to each of the illustrated embodiments may prevent the cleaning performance of the robot cleaner from being degraded.

The cleaning system may also achieve a reduction in energy and material costs by circulating air between the robot cleaner and the maintenance station.

The cleaning system may also easily achieve automatic dust discharge by discharging dust through the opening of the robot cleaner.

The cleaning system may cut off dust dispersed during automatic dust discharge, thereby keeping clean the surroundings of the maintenance station.

The cleaning system also may clean the sensors using circulating discharge air, thereby preventing dust from dispersed around the surroundings of the cleaning system.

Also, the cleaning system may effectively remove foreign matter wound on the brush unit during automatic dust discharge.

Claim 1:
A robot cleaner (<NUM>) comprising:
a body (<NUM>);
a driving unit (<NUM>) configured to enable the body (<NUM>) to autonomously travel about a region to be cleaned, and including driving wheels configured to be driven by at least one motor;
at least one brush (41b, 541b) configured to sweep dust on the surface of the region to be cleaned, and to rotate about a rotational axis;
a fan unit (<NUM>) configured to generate a suction force;
a dust box (<NUM>) detachably mounted to the body (<NUM>); and
a dust sensing unit (<NUM>);
characterized in that
the dust box (<NUM>) includes an inlet opening (<NUM>') extending in a direction substantially parallel to the rotational axis and adjacent to the at least one brush (41b, 541b), and configured to store dust introduced into an inside of the dust box (<NUM>) through the inlet opening (<NUM>'), and
the dust sensing unit (<NUM>) is mounted on the body (<NUM>) outside the dust box (<NUM>) and adjacent to the inlet opening (<NUM>') of the dust box (<NUM>), configured to sense dust accumulated in the inside of the dust box (<NUM>) adjacent to the inlet opening (<NUM>') of the dust box (<NUM>), and includes:
a light emitting unit (44a) mounted on the body (<NUM>) outside the dust box (<NUM>) and adjacent to the inlet opening (<NUM>'), and configured to emit light through the inside of the dust box (<NUM>), and
a light receiving sensor (44b) mounted on the body (<NUM>) outside the dust box (<NUM>) and adjacent to the inlet opening (<NUM>'), and configured to receive the light emitted by the light emitting unit (44a) through the inside of the dust box (<NUM>),
wherein the light emitted by the light emitting unit (44a) travels through the inside of the dust box (<NUM>) at the inlet opening (<NUM>') of the dust box (<NUM>) to the light receiving sensor (44b) in a direction parallel to the rotational axis.