AU2008276858B2

AU2008276858B2 - Vacuum cleaner and method of controlling the same

Info

Publication number: AU2008276858B2
Application number: AU2008276858A
Authority: AU
Inventors: Gun-Ho Ha; Jin-Young Kim; Hyuk-Min Kwon; Chang-Hoon Lee; Young-Gun Min; Jin-Wook Seo; Myung-Sig Yoo; Chang-Ho Yun
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2007-07-16
Filing date: 2008-01-21
Publication date: 2011-02-03
Anticipated expiration: 2028-01-21
Also published as: EP2173227A4; EP2173227B1; EP2173227A1; WO2009011482A1; AU2008276858A1

Description

1 Description VACUUM CLEANER AND METHOD OF CONTROLLING THE SAME Technical Field [1] The present disclosure relates to a vacuum cleaner and a method of controlling the same. Background Art [2] Generally, a vacuum cleaner is an electrically powered cleaning device that suctions air containing dust in a main body using suction generated by a suction motor and filters off the dust in a main body. [3] The vacuum cleaner includes a suction nozzle for suctioning air containing the dust, a main body connected to the suction nozzle, an extension pipe directing the air suctioned by the suction nozzle toward the main body, and a connection pipe directing the air passing through the extension pipe to the main body. [4] A dust collection unit for separating and storing the dust is detachably mounted in the main body. The dust collection unit functions to separate the dust contained in the air suctioned by the suction nozzle and store the separated dust. [5] When the vacuum cleaner stops operating during the dust separation process in the dust collection unit, the separated dust is stored in the duct collection unit under a relatively low density state. [6] According to the related art dust collection unit, a volume of the dust stored in the dust collection unit is too big as compared with a weight of the dust. Therefore, the dust collection unit must be frequently emptied in order to maintain a proper dust collection performance. This is troublesome for the user. [7] Therefore, in order to improve the use convenience of the vacuum cleaner, a vacuum cleaner that can maximize the dust collection volume and improve the dust collection performance has been recently developed. [8] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the priority date of the claims herein.

2 Disclosure of Invention [11] In accordance with a first aspect of the present invention, there is provided a vacuum cleaner including a cleaner main body in which a suction motor for generating suction is disposed; a dust collection unit detachably mounted on the cleaner main body and defining a dust storing portion; a compression member for compressing dust stored in the dust storing portion; a compression motor for driving the compression member; a mode selection unit for selecting an operational mode of the compression motor; and a control unit for controlling operation of the compression motor in accordance with the selected mode. [12] In accordance with another aspect of the present invention, there is provided a vacuum cleaner including a cleaner main body in which a suction motor for generating suction force is disposed; a dust collection unit detachably mounted on the cleaner main body and defining a dust storing portion; at least one compression member for compressing dust stored in the dust storing portion; a driving unit for driving the compression member; a control unit for determining if the compression member malfunctions; and a signal display unit for displaying a malfunction signal of the compression member. [13] In accordance with another aspect of the present invention, there is provided a method of controlling a vacuum cleaner, including storing dust in a dust storing portion by operation of a suction motor; measuring an operation time of the suction motor; and operating an compression motor for driving a compression member compressing the dust stored in the dust storing portion when the operation time of the suction motor is greater than a preset time. [14] Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof Advantageous Effects [15] According to the embodiments, since the dust stored in the dust collection unit are compressed by the compressing member, an amount of the dust that can be stored in the dust collection unit can be maximized.

2a [16] In addition, as the dust collection amount of the dust collection unit is maximized, there is no need to frequently empty the dust collection unit. [17] Further, since the dust maintain a compressed state in the dust collection unit, the scattering of the dust can be prevented when the dust collection unit is emptied. [18] Also, because the amount of dust collected in the dust collection unit is visible to the outside, a user can easily check the amount of dust. [19] In addition, when a predetermined amount of the dust is collected in the dust collection unit, the unit empty signal is displayed and thus the user can easily identify WO 2009/011482 PCT/KR2008/000376 3 the empty timing. [20] Additionally, when the suction motor operates, the compression motor begins operating after a predetermined time elapses, so that needless operation of the com pression motor can be reduced during the initial operation of the suction motor. [21] In addition, since the operational mode of the compression motor can be selected, the compression motor can be effectively operated in accordance with an amount of the dust stored in the dust collection unit. [22] Further, since the malfunction signal of the first compression member is displayed and the compression motor stops operating, overload of the compression motor can be prevented and thus the reliability of the product can be improved. Brief Description of the Drawings [23] Fig. 1 is a perspective view of a vacuum cleaner according to a first embodiment. [24] Fig. 2 is a perspective view of the vacuum cleaner of Fig. 1, when a dust collection unit is separated. [25] Fig. 3 is a sectional view of a dust collection unit according to a first embodiment. [26] Fig. 4 is a sectional view taken along line I-I'of Fig. 3. [27] Fig. 5 is a bottom perspective view of the dust collection unit of Fig. 3. [28] Fig. 6 is a bottom perspective view of a driven gear according to a first embodiment. [29] Fig. 7 is a perspective view of a dust collection unit mounting portion according to a first embodiment. [30] Fig. 8 is a view of a coupling relationship between a driven gear and a micro switch. [31] Fig. 9 is a perspective view of a handle according to a first embodiment. [32] Fig. 10 is an enlarged view of a portion A of Fig. 9. [33] Fig. 11 is a block diagram illustrating a control structure of a vacuum cleaner according to a first embodiment. [34] Fig. 12 is phase wave forms of a current and power of a compression motor in ac cordance with a dust compression time. [35] Figs. 13 and 14 are views illustrating an on-state of a micro switch when a first com pression member for compressing dust approaches a first side of a second compression member. [36] Figs. 15 and 16 are views illustrating an off-state of a micro switch when first and second compression members are inline. [37] Figs. 17 and 18 are views illustrating an on-state of a micro switch when a first com pressing ember for compressing dust approaches a second side of a second com pression member. [38] Fig. 19 is a view generally illustrating rotational operation of the first compression member depicted in Figs. 13 through 18.

WO 2009/011482 PCT/KR2008/000376 4 [39] Fig. 20 is a graph illustrating an on/off state of a micro switch in accordance with ro tational motion of the first compression member. [40] Fig. 21 is a flowchart illustrating a control method of a vacuum cleaner according to a firs embodiment. [41] Fig. 22 is a block diagram illustrating a control structure of a vacuum cleaner according to a second embodiment. [42] Fig. 23 is a perspective view of a driven gear according to a third embodiment. [43] Fig. 24 is a perspective view of a dust collection unit mounting portion according to a third embodiment. [44] Fig. 25 is a perspective view of a vacuum cleaner according to a fourth embodiment. [45] Fig. 26 is a block diagram illustrating a control structure of a vacuum cleaner according to a fifth embodiment. Mode for the Invention [46] Reference will now be made in detail to the embodiments of the present disclosure, example of which are illustrated in the accompanying drawings. [47] Fig. 1 is a perspective view of a vacuum cleaner according to a first embodiment, Fig. 2 is a perspective view of the vacuum cleaner of Fig. 1, when a dust collection unit is separated, and Fig. 3 is a sectional view of a dust collection unit according to a first embodiment. [48] Referring to Figs. 1 through 3, a vacuum cleaner 10 of this embodiment includes a main body 100 in which a suction motor (not shown) for generating suction force is provided and a dust separating unit for separating dust from the air. [49] The vacuum cleaner 10 further includes a suction nozzle 20 for suctioning air containing the dust, a handle 40 for manipulating operation of the vacuum cleaner 10, an extension pipe 30 connecting the suction nozzle 20 to the handle 40, and a connection hose connecting the suction nozzle 20 to the main body 100. [50] Since structures of the suction nozzle 20, extension pipe 30, and connection hose 50 are well know in the art, detailed description thereof will be omitted herein. [51] A main body inlet 110 through which air containing the dust suctioned through the suction nozzle 20 is introduced is formed on a front-lower end of the main body 100. An outlet (not shown) through which the air from which the dust is separated is discharged to an external side is formed on a side of the main body 100. A main body handle unit 140 is formed on a top of the main body 100. [52] The dust separation unit includes a dust collection unit 200 having a first cyclone unit (which will be described later) for primarily separating the dust from the air and a second cyclone unit 300 and a second cyclone unit 300 for further separating the dust from the air from which the dust is primarily separated by the first cyclone unit. The WO 2009/011482 PCT/KR2008/000376 5 second cyclone unit 300 is provided in the main body 100. [53] The dust collection unit 200 is detachably mounted on a dust collection unit mounting portion 170 formed on a front portion of the main body 100. A mounting/ dismounting lever 142 is provided on the handle unit 140 of the main body 100 and the dust collection unit 200 is provided with a hook step 256 that is selectively engaged with the mounting/dismounting lever 142. [54] The dust collection unit 200 includes a first cyclone unit generating cyclone flow and a dust collection body 210 in which the dust separated by the first cyclone unit is stored. [55] As the dust collection unit 200 is mounted on the main body 100, the dust collection unit 200 communicates with the main body 100 and the second cyclone unit 300. [56] The main body is provided with an air outlet 130 through which the air suctioned into the main body 100 is discharged and the dust collection unit 200 is provided with a first air inlet 218 through which the air discharged through the air outlet 130 is in troduced. [57] The dust collection unit 200 is further provided with a first air outlet 252 through which the air from which the dust is separated in the first cyclone unit. The main body 100 is provided with a connection passage 114 along which the air discharged through the first air outlet 252 is introduced. The air introduced along the connection passage 114 is directed to the second cyclone unit 300. [58] The dust separated in the second cyclone unit 300 are stored in the dust collection unit 200. Therefore, the dust collection body 210 is provided with a dust inlet 254 through which the dust separated in the second cyclone unit 300 are introduced and a dust storing unit in which the dust separated in the second cyclone unit 300 are stored. [59] The vacuum cleaner of this embodiment includes a compression structure for com pressing the dust to maximize an amount of the dust stored in the dust collection unit 200. [60] The following will describe the vacuum cleaner having the dust collection unit maximizing a dust collection amount. [61] Fig. 4 is a sectional view taken along line I-I of Fig. 3, Fig. 5 is a bottom perspective view of the dust collection unit of Fig. 3, and Fig. 6 is a bottom perspective view of a driven gear according to a first embodiment. [62] Fig. 7 is a perspective view of a dust collection unit mounting portion according to a first embodiment and Fig. 8 is a view of a coupling relationship between a driven gear and a micro switch. [63] Referring first to Fig. 4, the dust collection unit 200 of this embodiment includes a dust collection body 210 defining an outer appearance, a first cyclone unit 230 that is selectively received in the dust collection body 210 to separate the dust from the air, WO 2009/011482 PCT/KR2008/000376 6 and a cover member 250 for selectively opening and closing the top of the dust collection body 210. [64] In more detail, the dust collection body 210 is formed in an approximately cylindrical shape and defines a dust storing portion therein. The dust storing portion includes a first dust storing section 214 in which the dust separated in the first cyclone unit 230 are stored and a second dust storing section 216 in which the dust separated in the second cyclone unit 300 are stored. [65] The dust collection body 210 includes a first wall 211 defining the first dust storing section 214 and a second wall 212 defining the second dust storing section 216 by as sociating with the first wall 211. That is, the second wall 212 is designed to enclose a portion of the outer side of the first wall 211. [66] The dust collection body 210 has an opened top and the cover member 25 is de tachably coupled to the top of the dust collection body 210. The first cyclone unit 230 is coupled to a lower portion of the cover member 250. [67] The first cyclone unit 230 is provided with a dust guide passage 232 along which the dust separated from the air can be effectively discharged to the first dust storing unit 214. The dust guide passage 232 guides the dust in a tangential direction and directs the dust downward. [68] An inlet 233 of the dust guide passage 232 is formed on a side surface of the cyclone unit 230 and an outlet 234 is formed on a bottom of the first cyclone unit 230. [69] The cover member 250 simultaneously opens and closes the first and second dust storing sections 214 and 216. An air outlet 251 through which the air from which the dust is separated in the first cyclone unit 230 is discharged is formed on a bottom of the cover member 250. A filter member 260 provided at an outer circumference with a plurality of through holes 262 each having a predetermined size is coupled to an under surface of the cover member 250. [70] Therefore, the air in the first cyclone unit 230 is discharged through the air outlet 251 via the filter member 260. [71] A passage 253 for directing the air of the first cyclone unit 230 toward the first air outlet 252 is formed in the cover member 250. That is, the passage 253 functions to connect the air outlet 251 to the first air outlet 252. [72] A pair of compression members 270 and 280 that increase a dust collection amount by reducing a volume of the dust stored in the first dust storing unit 214 are provided in the dust collection body 210. [73] The compression members 270 and 280 compress the dust stored in the first dust storing section by cooperating with each other, thereby maximizing the dust collection amount of the dust collection unit 200. [74] For convenience, the compression members 270 and 280 will be respectively referred WO 2009/011482 PCT/KR2008/000376 7 to as first and second compression members. [75] In this embodiment, at least one of the compression members 270 and 280 is movably disposed in the dust collection body 210 so that the dust can be compressed between the compression members 270 and 280. [76] When the first and second compression members 270 and 280 are rotatably provided in the dust collection body 210, the first and second compression members 270 and 280 rotate to move toward each other to compress the dust between the first and second compression members 270 and 280. [77] However, in this embodiment, the first compression member 270 is rotatably provided in the dust collection body 210 while the second compression member 280 is fixed in the dust collection body 210. Therefore, the first compression member 270 is a rotational member while the second compression member 280 is a stationary member. [78] In more detail, the second compression member 280 is provided between an inner circumference of the dust collection body 210 and a rotational shaft 272 defining a ro tational center of the first compression member 270. That is, the second compression member 280 is provided on a plan connecting an axis of the rotational shaft 272 to the inner circumference of the first dust storing section 214. At this point, the second com pression member 280 completely or partly blocks a space defined between the inner circumference of the first dust collection section 214 and the axis of the rotational shaft 272 so that the dust can be compressed by the first compression member 270 rotating. [79] That is, a first end of the second compression member 280 is integrally formed with the inner circumference of the dust collection body 210 and a second end of the second compression member 280 is integrally formed with a fixed shaft 282 that is provided on a common axis with the rotational shaft 272 of the first compression member 270. [80] Needless to say, only one of the first and second ends of the second compression member 280 may be integrally formed with the inner circumference of the dust collection body 210 or the fixed shaft 282. [81] Even when the first end of the second compression member 280 is not integrally formed with the inner circumference of the dust collection body 210, it is preferable that the first end of the second compression member 270 is disposed adjacent to the inner circumference of the dust collection body 210. [82] Even when the second end of the second compression member 280 is not integrally formed with the fixed shaft 282, it is preferable that the second end of the second com pression member 270 is disposed adjacent to the fixed shaft 282. [83] Therefore, the leakage of the dust through a clearance formed on a side of the second compression member 280 can be minimized when the dust is rushed by the first com pression member 270. [84] The first and second compression members 270 and 280 have respective rectangular WO 2009/011482 PCT/KR2008/000376 8 plates. The rotational shaft 272 of the first compression member 270 is provided on a common axis with a vertical axis defining a center of the dust collection body 210. [85] The fixing shaft 282 protrudes from a first end of the dust collection body 210 toward an inside. A hollow portion 283 formed in an axial direction is formed inside the fixing shaft 282 to fix the rotational shaft 272. That is, the rotational shaft 272 is partly inserted from a top of the fixing shaft 282 into the hollow portion 283. [86] The rotational shaft 272 is provided with a stepped portion 272c supported by a top of the fixing shaft 282. The rotational shaft 272 is divided into upper and lower shafts 272a and 272b with reference to the stepped portion 272c. The compression member 270 is coupled to the upper shaft 272a. A driven gear rotating the first compression member 270 is coupled to the lower shaft 272b. [87] The vacuum cleaner of this embodiment further includes a driving device for driving the first compression member 270. [88] The following will describe a relationship between the dust collection unit 200 and the driving device with reference to Figs. 5 through 8. [89] Referring to Figs. 5 through 8, the driving device for rotating the first compression member 270 includes a driving unit (not shown) for generating driving force and a power transmission unit for transmitting the driving force of the driving unit to the first compression member 270. [90] In more detail, the power transmission unit includes a driven gear 410 coupled to the rotational shaft 272 of the first compression member 270 and a driving gear 420 transmitting the power to the driven gear 410. The driving unit may be a compression motor coupled to the driving gear. [91] A gear shaft 414 of the driven gear 41 is coupled to the rotational shaft 272 of the first compression member 270 at a lower side of the dust collection body 210. As the driven gear 41 is coupled to the lower side of the dust collection body 210, the driven gear 410 is exposed out of the dust collection body 210. [92] The compression motor is provided under the dust collection unit mounting portion 170 and the driving gear 420 is provided on a bottom surface of the dust collection unit mounting portion 170 and coupled to the rotational shaft of the compression motor. [93] A portion of the outer circumference of the driving gear 420 is exposed to the external side at the bottom of the dust collection unit mounting portion 170. The dust collection unit mounting portion 170 is provided at a bottom with an opening 173 for exposing the portion of the outer circumference of the driving gear 420 to the dust collection unit mounting portion 170. [94] As the driven gear 410 is exposed to the dust collection mounting portion 170, the driven gear 410 is engaged with the driving gear 420 when the dust collection unit 200 is mounted on the dust collection unit mounting portion 170.

WO 2009/011482 PCT/KR2008/000376 9 [95] Therefore, when the compression motor is driven, the driving gear 420 coupled to the compression motor rotates to transmit torque of the compression motor to the driven gear 410. The torque transmitted to the driven gear 410 rotates the first compression member 270. [96] A guide rib 290 for guiding the mounting of the dust collection unit 200 is formed on a lower side of the dust collection body 210. The dust collection unit mounting portion 170 is provided with an insertion groove 172 in which the guide rib 290 is inserted. [97] The guide rib 290 is provided in a C-shape at an outer side of the driven gear 410 to enclose a portion of the driven gear 410. Therefore, the guide rib 290 functions to protect the driven gear 4100 and prevent the dust from moving toward the driven gear 410. [98] A micro switch 430 for detecting a rotational position of the driven gear 410 is provided under the dust collection unit mounting portion 170. A terminal unit 44 for turning on/off the micro switch 430 by contacting the driven gear 410 is exposed to the dust collection unit mounting portion 170. [99] A through hole 177 for exposing a part of the terminal unit 440 is exposed to the external side is formed in the dust collection unit mounting portion 170. Inner and outer ribs 178 and 179 for protecting the exposed terminal unit 440 are formed on an edge of the through hole 177. [100] The following will describe a relationship between the driven gear and the micro switch. [101] Referring to Figs. 6 through 8, the micro switch 430 is disposed under the driven gear 410 such that the terminal unit 440 turning on/off the micro switch can contact a lower portion of the driven gear 410. [102] The driven gear 410 includes a body unit 412, a contact rib 413 extending downward from the lower edge of the body unit 412 and contacting the terminal unit 440, a plurality of gear teeth formed along a side surface of the body unit 412. [103] The contact rib 413 is provided with an identification groove 415 for identifying the position of the driven gear 410 by disallowing the driven gear 410 in a predetermined position to contact the terminal unit 440. The non-contacting of the terminal unit 440 with the contact rib 413 means that a portion of the terminal unit 440 is inserted and thus does not contact the under surface of the contact rib 413. [104] When the dust collection unit 200 is mounted on the dust collection unit mounting portion 170, the terminal unit 440 exposed through the through hole 177 contacts the under surface of the contact rib 413 to press a contact point 432 of the micro switch 430. In addition, when the driven gear 410 rotates to a predetermined position, the terminal unit 440 is partly inserted in the identification groove 415 and thus the terminal unit 440 is detached from the contact point 432.

WO 2009/011482 PCT/KR2008/000376 10 [105] The micro switch 430 is turned off only when the terminal unit 440 is located in the identification groove 415. The micro switch 430 maintains the on-state when the terminal unit 440 contacts the contact rib 413. [106] Therefore, when the driven gear 410 rotates, the micro switch 430 maintains the on state except when the terminal unit 440 is located in the position identification groove 415. [107] On the contrary, the micro switch 430 is turned on only when the terminal unit 440 is located in the location identification groove 415. In other cases, the micro switch 430 is turned off when the terminal unit 440 contacts the contact rib 413. [108] The gear tooth 416 is provided at a lower portion with an interference preventing groove 417 for preventing the dust collection unit 200 from interfering with the outer rib 179 when the dust collection unit 200 is mounted. [109] Therefore, when the dust collection unit 200 is mounted on the dust collection mounting portion 170, the outer rib 179 is located in the interference preventing groove 417 and the inner rib 178 is located in a space defined by the contact rib 413. [110] The micro switch 430 detects the mounting of the dust collection unit 200. That is, when the dust collection unit 200 is mounted on the dust collection unit mounting portion 170, the contact rib 413 presses the terminal unit 440. Then, the terminal unit 440 presses the contact point 432 formed on the micro switch 430 to turn on the micro switch. [111] That is, since the micro switch 430 is turned on when the dust collection unit is mounted, the mounting of the dust collection unit 200 can be detected by the micro switch 430. Here, the reason for detecting the mounting of the dust collection unit 200 is to prevent the suction motor and the compression motor from operating in a state where the dust collection unit 200 is not mounted. [112] The mounting of the dust collection unit 200 is detected by the micro switch 430 in this embodiment. However, the present disclosure is not limited to this embodiment. For example, a pressure sensor may be mounted on the dust collection unit mounting portion 170. [113] Fig. 9 is a perspective view of a handle according to a first embodiment and Fig. 10 is an enlarge view of a portion A of Fig. 9. [114] Referring to Figs. 9 and 10, the handle 400 of this embodiment includes a handle body 41 and a grasping portion 42 grasped by the user and provided above the handle body 41. [115] A manipulation unit 44 is provided on the grasping portion 42 to manipulate the operation of the vacuum cleaner 10. For example, the operation of the suction motor and the on/off of the compression motor can be controlled by the manipulation unit 44. In addition, a mode selection unit 45 for selecting the operational mode of the com- WO 2009/011482 PCT/KR2008/000376 11 pression motor is provided at a side of the manipulation unit 44. The operational mode will be described in more detail later. [116] A dust amount display unit 46 is formed at a side of the manipulation unit 44 to display an amount of the dust stored in the dust collection unit 200. [117] In more detail, the dust amount display unit 45 has a plurality of dust amount display sections 45a that are sequentially arranged. LEDs (not shown) are provided in the re spective dust amount display sections 45a. As the amount of the dust increases, the number of the LEDs that are turned on increases and thus the number of the dust amount display sections 45a that are turned on increases. In Fig. 10, the reference characters E and F indicate "empty" and "full", respectively. [118] Therefore, the dust amount display sections are sequentially increased from E to F and the user can identify the amount of the dust stored in the dust collection unit 200 by identifying the number of the dust amount display sections 45a that are turned on. [119] Fig. 11 is a block diagram illustrating a control structure of a vacuum cleaner according to a first embodiment and Fig. 12 is phase wave forms of a current and power of a compression motor in accordance with a dust compression time, wherein Fig. 12A is a current phase waveform of the compression motor and Fig. 12B is a power phase waveform [120] Referring to Figs. 11 and 12, the vacuum cleaner of this embodiment includes a control unit 520, a signal input unit 520 for inputting an operational condition of the vacuum cleaner, a suction motor driver 540 for operating a suction motor 550 in ac cordance with an operational mode input from the signal input unit 520, a compression motor driver 560 for operating the compression motor 570 compressing the dust, a driving gear driven by the compression motor 570, a driven gear 410 engaged with the driving gear 420, a micro switch 430 that is turned on and off in accordance with the rotation of the driven gear 410, and a counter unit 580 for measuring an on/off time of the micro switch 430. [121] The vacuum cleaner of this embodiment further includes a current detecting unit 580 for detecting a current value of the compression motor 570, a display unit 595 for displaying malfunction of the compression member 270, and a dust amount display unit 46 for displaying a dust amount of the dust collection unit. [122] As described above, the compression motor 570 is provided under the dust collection unit mounting portion 170 to rotate the driving gear 420. [123] The compression motor may be a reversible motor. That is, the compression motor may be a motor that can rotate in opposite directions. [124] Therefore, the first compression member 270 can rotate in forward and rearward directions and thus the dust is accumulated at both sides of the second compression member 280.

WO 2009/011482 PCT/KR2008/000376 12 [125] Therefore, the compression motor may be a synchronous motor that can rotate in opposite directions. [126] The synchronous motor is designed to rotate in the opposite directions by the motor itself. When the load applied to the motor is greater than a predetermined value as the motor rotates in a first direction, the motor is designed to rotate in a second direction. The load applied to the motor is torque. [127] Since the synchronous motor is well known in the art, detailed description thereof will be omitted herein. [128] At this point, when the load applied to the first compression member 270 is greater than the predetermined value, the current value of the compression motor 570 is steeply increased as shown in Fig. 12A. [129] In more detail, when the first compression member 270 rotates in the first direction, the dust between the first and second compression members 270 and 280 are com pression as the first compression member 310 rotates to a side of the second com pression member 280. The rotation of the first compression member 270 continues until the load applied to the motor reaches the predetermined value. [130] When the load reaches the predetermined value, the current value of the compression motor 570 steeply increases and this current variation is detected by the current detecting unit 580. [131] The current value detected by the current detecting unit 580 is transmitted to the control unit 510 and the control unit 510 transmits a signal for interrupting the electric power to the compression motor driver 560. Then, the compression motor 570 stops operating and thus the first compression member 270 stops in a dust compression state. The first compression member 270 keeps compressing the dust for a reference cut-off time t at the stopped position. [132] When the reference cut-off time t has elapsed, the control unit 510 transmits a power applying signal of the compression motor 570 to the compression motor driver 560 and thus the compression motor 570 and the first compression member 270 rotate. [133] Since the first compression member 270 stops rotating in a state where the load reaches the predetermined value, the first compression member 270 rotates in the second direction. [134] When the second compression member 270 rotates in the second direction, the dust between the first compression member 270 and the second compression member 280 are compressed as the first compression member 270 rotates toward the second side of the second compression member 280. [135] As described above, when the load applied to the compression member 270 reaches the predetermined value during the rotation of the first compression member 270, the electric power applied to the compression motor 570 is cut off and thus the first com- WO 2009/011482 PCT/KR2008/000376 13 pression member 270 stops rotating in a state where it compresses the dust. In addition, the first compression member 270 keeps compressing the dust for the reference cut-off time t at a position where the first compression member 270 stops. [136] When the predetermined time has elapsed, the compression motor 570 is driven again and thus the first compression member 270 rotates in an opposite direction. [137] When the reference cut-off time is relatively short (i.e., substantially close to 0), the dust is continuously compressed at both sides of the second compression member 270. When the reference cut-off time is relatively long, the dust is continuously compressed at one side of the second compression member and the power consumption of the com pression motor can be reduced by the intermittent operation of the compression motor. [138] That is, when an amount of the dust stored in the dust collection unit 200 per unit time, there is no need to unnecessarily rotate the compression motor 570. In this case, the reference cut-off time may be increased. [139] Therefore, in this embodiment, the operational mode of the compression motor 570 may include a first mode having a short reference cut-off time and a second mode having a long reference cut-off time. The operation mode of the compression motor may be selected by the mode selection unit 45 (see Fig. 9). [140] At this point, since it can be regarded that the compression motor 570 continuously operates in the first mode, the first mode may be referred to as "Continuous Mode". [141] Figs. 13 and 14 are views illustrating an on-state of a micro switch when a first com pression member for compressing dust approaches a first side of a second compression member, Figs. 15 and 16 are views illustrating an off-state of a micro switch when first and second compression members are inline, and Figs. 17 and 18 are views illustrating an on-state of a micro switch when a first compressing ember for compressing dust ap proaches a second side of a second compression member. [142] Referring to Figs. 13 through 18, when the first compression member 270 rotates by 180-degree with reference to the second compression member 280 and thus is disposed inline, the terminal unit 440 is located in the position identification groove 415 of the driven gear 410. In this case, the terminal unit 440 is spaced apart from the contact point 432 and thus the micro switch 430 is turned off. [143] The position of the first compression member 270 depicted in Fig. 15, where the micro switch 430 is turned off, will be referred to as "reference position" for the de scriptive convenience. [144] While the first compression member 270 compresses the dust stored in the dust collection body 210 as it rotates counterclockwise from the reference position, the terminal unit 440 contacts the contact rib 413 of the driven gear 410. Therefore, as shown in Fig. 14, the terminal unit 440 presses the contact portion 432 of the micro switch 430 and thus the micro switch 430 is turned on.

WO 2009/011482 PCT/KR2008/000376 14 [145] When the first compression member 270 cannot rotate counterclockwise due to the dust, the first compression member 270 rotates clockwise. [146] Therefore, the first compression member 270 rotates toward the right side of the second compression member 280 as shown in Fig. 17 over the reference position shown in Fig. 15, thereby compressing the dust stored in the dust collection body 210. [147] When the first compression member 270 cannot rotate clockwise due to the compressed dust, the compression motor 570 rotates counterclockwise and the above described process is repeated, thereby compressing the dust stored in the dust collection body 210. [148] Fig. 19 is a view for generally describing the rotational operation of the first com pression member that is described with reference to Figs. 13 through 18. [149] Fig. 19 shows a first reciprocation time TB 1 taken when the first compression member 270 rotates clockwise from the reference position and is returned to the reference position and a second reciprocation time TB2 taken when the first com pression member 270 rotates counterclockwise from the reference position and is returned to the reference position. [150] Since the dust is uniformly dispersed in the dust collection body 210, the first recip rocation time TB 1 is almost same as the second reciprocation time TB2. [151] Meanwhile, as an amount of the dust compressed by the first compression member 270 increases, the first and second reciprocation times TB 1 and TB2 are shortened. [152] In this embodiment, the amount of the dust stored in the dust collection body is de termined by detecting the first and second reciprocation times TB 1 and TB2. [153] Fig. 20 is a graph illustrating an on/off state of the micro switch in accordance with the reciprocation motion of the first compression member. [154] Fig. 19 shows a first reference time TCl taken when the first compression member 270 rotates clockwise from the reference position and is returned to the reference position in a state where no dust is stored in the dust collection unit 200 and a second reference time TC2 taken when the first compression member 270 rotates counter clockwise from the reference position and is returned to the reference position in a state where no dust is stored in the dust collection unit 200. The reference times TCl and TC2 mean that an on-time of the micro switch. [155] At this point, when the dust is continuously stored in the dust collection unit 200, the actual reciprocation times TB 1 and TB2 of the first compression member 270 become less than the reference times TCl and TC2. [156] However, when the first compression member 270 malfunctions, the actual recip rocation times TB 1 and TB2 of the first compression member 270 may be greater than the reference times TCl and TC2. [157] For example, when foreign objects clog between the first compression member 270 WO 2009/011482 PCT/KR2008/000376 15 and the dust collection body 210, the rotational speed of the first compression member 270 may be significantly reduced as compared with its original speed or the first com pression member 270 stops rotating. [158] In this case, the on-time of the micro switch 430 becomes greater than the reference times TCI and TC2. [159] Therefore, in this embodiment, in order to determine if the first compression member 170 malfunctions, it is determined if the actual reciprocation times TB 1 and TB2 of the first compression member 270 are greater than limit times TD 1 and TD2 greater than the reference times TCl and TC2. [160] At this point, the reason for comparing the actual reciprocation times of the first com pression member 270 with the limit times is to accurately determine the malfunction of the compression motor 570 considering the rotational error. [161] In this embodiment, the malfunction of the first compression member is determined by comparing the actual reciprocation times of the first compression member 270 with the limit times. However, the malfunction may be further determined by comparing a time for which the first compression member 270 is in the reference position with a limit time TB3. [162] As described above, the micro switch 430 functions as a position detecting unit for detecting the reference position of the first compression member 270 by cooperating with the driven gear 410. The micro switch 430 function functions as a malfunction detecting unit for detecting the malfunction of the first compression member 270 during the on/off process of the micro switch. [163] The following will describe a dust compression process. [164] Fig. 21 is a flowchart illustrating a control method of the vacuum cleaner according to a first embodiment. [165] Referring to Fig. 21, the user operates the vacuum cleaner by selecting one of high, medium, low modes representing suction power using the signal input unit 520. Then, the control unit 510 operates the suction motor driver 540 to operate the suction motor 550 in accordance with the selected suction mode (S10). [166] When the suction motor 550 operates, the dust is suctioned through the suction nozzle by the suction of the suction motor 550. The air suctioned through the suction nozzle is directed into the main body 100 through the main body suction unit 110. The introduced air is directed into the dust collection unit 200 along a predetermined passage. [167] The air introduced into the dust collection unit 200 goes through a dust separation process, after which the air is discharged to the main body 100. The separated dust is stored in the first dust storing section 214. [168] During the dust separation process by the operation of the suction motor 550, the WO 2009/011482 PCT/KR2008/000376 16 control unit 510 determines if the on-time of the suction motor reaches an operation reference time TA 1 (S 11). At this time, the operation reference time TA 1 is measured by the counter unit 580. [169] When the on-time of the suction motor 550 reaches the reference time TA1, the control unit 510 operates the compression motor to compress the dust stored in the dust collection unit 200 (S 12). [170] At this point, when the user does not select the operational mode of the compression motor 570 through the mode selection unit 45, the compression motor 570 operates with a former mode or a first mode (continuation mode). [171] Here, the reason for operating the compression motor 570 after the predetermined time has elapsed after the suction motor 550 operates is to prevent the compression motor 570 from unnecessarily operating during an initial operation of the suction motor 550. [172] That is, when the suction motor 550 operates in a state where no dust is stored in the dust collection unit 200, a predetermined time for accumulating a predetermined amount of the dust in the dust collection unit 200 is necessary. That is, there is no need to operate the compression motor 570 until the predetermined amount of the dust is stored in the dust collection unit 200. [173] Therefore, the compression motor 570 maintains a stopped state until the prede termined amount of the dust is stored in the dust collection unit 200 to prevent the compression motor 570 from unnecessarily operating. [174] Even when the suction motor 550 operates in a state where the dust is stored in the dust collection unit 200, since the dust is compressed before the suction motor 570 operates, the stopped state of the compression motor 570 is maintained until a prede termined amount of the dust is additionally accumulated in the dust collection unit 200, thereby preventing the compression motor from unnecessarily operating. [175] When the compression motor 570 is driven, the driving gear 420 coupled to the ro tational shaft of the compression motor 570 rotates and thus the driven gear 410 engaged with the driving gear 420 rotates. When the driven gear 410 rotates, the first compression member 270 coupled to the driven gear 410 rotates toward the second compression member 280 to compress the dust. [176] At this point, the control unit 510 first determines if the first compression member 270 is in the reference position (S13). In this embodiment, since the first and second reciprocation times are measured with reference to the reference position of the first compression member 270, it is required to determine if the first compression member 270 is in the reference position when the compression is initiated. The reference position of the first compression member 270 may be a time point where the micro switch 430 is initially turned off.

WO 2009/011482 PCT/KR2008/000376 17 [177] Therefore, the counter unit 580 measures the first or second reciprocation time TB 1 or TB2 with reference to the time point where the micro switch is initially turned off (S14). [178] Here, as an amount of the dust compressed in the dust collection unit 210 by the first and second compression members 270 and 280 increases, the reciprocation time of the driven gear 410 is shortened. In addition, the control unit determines a current dust amount using the reciprocation time detected. The determined dust amount is displayed on the dust amount display unit 46. [179] After the above, the control unit 510 determines if the first or second reciprocation time TB1 or TB2 is greater than the limit times TD1 and TD2 (S 15). [180] When it is determined that the first or second reciprocation time TB 1 or TB2 is less than the limit times TD 1 and TD2, it is determined if one of the first and second recip rocation time reaches preset times TEl and TE2 (S 16). The preset times TEl and TE2 are times set in the control unit 510 by a designer to be used as a reference for de termining a predetermined amount of the dust accumulated in the dust collection unit 200. [181] The preset times TEl and TE2 are obtained in accordance with repeated tests performed by the designer and varied in accordance with a volume of the vacuum cleaner. In addition, the preset times TE 1 and TE2 are less than the reference times TC 1 and TC2 that are the reciprocation time of the first compression member 270 when no dust is accumulated in the dust collection unit 200. [182] In this embodiment, when one of the reciprocation times TB 1 and TB2 of the first compression member 270 reaches the preset times TEl and TE2, it is determined that a predetermined amount of the dust is accumulated. However, the present disclosure is not limited to this embodiment. For example, it is determined that the predetermined amount of the dust is accumulated when both of the reciprocation times TB 1 and TB2 reach the preset times TE 1 and TE2. [183] When it is determined that at least one of the reciprocation times TB 1 and TB2 is greater than the preset times TEl and TE2, the process is returned to the step S15 to repeat the above-described process. [184] When at least one of the first and second reciprocation times TB 1 and TB2 reaches the preset times TEl and TE2, the control unit 510 determines if the number of times that one of the first or second reciprocation time TB 1 or TB2 reaches the preset times TEl and TE2 continuously reaches the predetermined number N of times (e.g., 3 times) (S 17). [185] By doing this, it can be accurately determined that an amount of the dust stored in the dust collection unit 200 is greater than a predetermined amount. Further, an error that may be caused by the first compression member 270 that cannot normally operate due WO 2009/011482 PCT/KR2008/000376 18 to the foreign objects can be prevented. The abnormal rotation of the first compression member 270 means a case where the first compression member 270 rotates toward the second side of the second compression member 280 in a state where the first com pression member 270 cannot rotate toward the first side of the second compression member due to the foreign objects clogging between the first compression member 270 and the dust collection body 210. [186] That is, in this embodiment, the malfunction of the first compression member 270 includes a case where the rotational speed of the first compression member is reduced due to the foreign objects clogging between the first compression member 270 and the dust collection body 210 and a case where the rotation direction change of the first compression member 270 is abnormally performed. [187] In the step S17, when it is determined that the number of times is less than the prede termined number of times, the process is returned to the step S15. When it is de termined that the number of times reaches the predetermined number of times, a dust collection unit empty signal is displayed (S 17). [188] In this embodiment, the empty signal may be displayed on the dust amount displaying unit 45 or by a repeated turn on/off signal of the LEDs provided under the dust amount display sections 45a. Alternatively, the empty signal may be transmitted by sound generated by a speaker provided on the vacuum cleaner. [189] Next, the control unit 510 stops the operation of the suction motor 550 (S20) and the operation of the compression motor 570 (S20). [190] The reason for forcedly stopping the operation of the suction motor 550 is to prevent the dust suction efficiency from be deteriorated when the amount of the dust stored in the dust collection unit 200 is greater than a predetermined amount and to prevent the suction motor 550 from being overloaded. [191] In the step S15, when it is determined that at least one of the first and second recip rocation times TB 1 and TB2 of the first compression member 270 is greater than the limit times TD 1 and TD2, the control unit 510 determines that the compression member 270 malfunctions. [192] The control unit 510 transmits a malfunction signal of the first compression member 270 to the display unit 530 so that the malfunction display unit 595 displays the mal function signal of the first compression member 270 (S 19). Next, the control unit 510 stops the operation of the suction motor 550 and the operation of the compression motor 570 (S21). [193] As described above, according to this embodiment, the amount of the dust stored in the dust collection unit 200 and the unit empty timing are displayed and thus the user convenience can be improved. [194] Further, since the malfunction signal of the first compression member is displayed WO 2009/011482 PCT/KR2008/000376 19 and the compression motor stops operating, the overload of the compression motor can be prevented and thus the reliability of the product can be improved. [195] Fig. 22 is a block diagram of a control structure of a vacuum cleaner according to a second embodiment. [196] This embodiment is substantially same as the first embodiment except for a dust amount determining method. Therefore, the following will describe only the features of this embodiment. [197] Referring to Fig. 22, the vacuum cleaner of this embodiment further includes a rotation detecting unit 597 for detecting the number of rotation of the compression motor 570. The rotation detecting unit 597 detects the number of first reciprocations each taken when the first compression member 270 rotates clockwise from the reference position and is returned to the reference position and the number of second reciprocations each taken when the first compression member 270 rotates counter clockwise from the reference position and is returned to the reference position. That is, in this embodiment, the rotation range of the first compression member 270 is de termined by measuring the number of rotation of the compression motor 570. [198] The control unit 510 determines the amount of the dust with reference to the number of the first reciprocation rotation and the number of the second reciprocation rotation to display the current dust amount on the dust amount display unit 46. In addition, when the number of the first or second reciprocating rotation reaches a reference recip rocating rotation number, the control unit 510 displays the empty signal. [199] Fig. 23 is a perspective view of a driven gear according to a third embodiment and Fig. 24 is a perspective view of a dust collection unit mounting portion according to a third embodiment. [200] This embodiment is identical to the first embodiment except for the reference position identifying means. Therefore, the following will describe only the feature of this embodiment. [201] Referring to Figs. 23 and 24, a magnetic member 615 is provided on a lower edge of a driven gear 610. [202] A magnetism detecting unit 640 for detecting magnetism generated by the magnetic member 615 is provided inside the dust collection unit mounting portion 170. A hall sensor may be used as the magnetism detecting unit 640. [203] In order for the magnetism detecting unit 640 to effectively detect the magnetism generated from the magnetic member 615, it is preferable that the magnetism detecting unit 640 is disposed right under the trace drawn by the magnetic member 615 when the dust collection unit 200 is mounted on the dust collection unit mounting portion 170 and the driven gear 610 rotates. [204] Therefore, when the magnetic member 615 is disposed right above the magnetism WO 2009/011482 PCT/KR2008/000376 20 detecting unit 640 during the rotation of the driven gear 610, the magnetism detecting unit 640 detects the magnetism of the magnetic member 415 and thus the reference position of the driven gear 410 can be identified. [205] Alternatively, in order to identify the reference position of the first compression member 270, an infrared sensor may be used. The infrared sensor may be provided on the terminal unit described in the first embodiment and exposed to the dust collection unit mounting portion. [206] Alternatively, a photo sensor may be also used. In this case, the brightness of the identification groove 415 of the driven gear 410 is different from that of the contact rib 413 so that the position identification groove 415 of the driven gear 410 can be detected by the photo sensor and thus the reference position of the first compressing member 270 can be determined. [207] Fig. 25 is a perspective view of a vacuum cleaner according to a fourth embodiment. [208] This embodiment is substantially identical to the first embodiment except for the type of the vacuum cleaner. Therefore, the following will describe only the features of this embodiment. [209] Referring to Fig. 25, in this embodiment, an upright type vacuum cleaner is proposed. [210] In more detail, the upright type vacuum cleaner 700 includes a suction nozzle 720 suctioning the air containing the dust while moving along a floor and a main body 710 rotatably coupled to the suction nozzle 720 and provided with a suction unit therein, and a dust collection unit 730 selectively mounted on the main body 710. [211] In more detail, a handle 712 is formed on a top of the main body 710. A ma nipulation button 714, a mode selection unit 615 for selecting an operation mode of the compression motor, a dust amount display unit 716 for displaying an amount of the dust stored in the dust collection unit 730 are formed on the handle 712. [212] Therefore, the user can easily control the operation of the suction unit and the com pression motor when he/she graphs the handle 712 and performs the cleaning work by moving the main body 710 and the suction nozzle 720. [213] Fig. 26 is a block diagram illustrating a control structure of a vacuum cleaner according to a fifth embodiment of the present disclosure. [214] This embodiment is substantially identical to the first embodiment except that the empty signal is separately displayed from the dust amount. Therefore, the following will describe only feature of this embodiment. [215] Referring to Fig. 26, the vacuum cleaner of this embodiment includes a dust amount display unit 830 for displaying an amount of the dust stored in the dust collection unit, an empty signal display unit 830 for displaying a dust dumping signal, and a control unit 810 for controlling the operation of the dust amount display unit 830 and the WO 2009/011482 PCT/KR2008/000376 21 empty signal display unit 820. [216] In detail, the display region of the dust amount display unit 830 that displays the amount of dust may be expanded, or the color of an illuminated LED may be altered. [217] In more detail, the empty signal display unit 820 may provide a visual signal or an audio signal. For example, the empty signal display unit 820 may be comprised of a buzzer circuit or a speaker. [218] The malfunction display of the first compression member is separately displayed on a malfunction display unit or on the empty signal display unit 820. Needless to say, when the malfunction signal of the first compression signal is displayed on the empty signal display unit 820, the malfunction signal may be differently set from the empty signal.

Claims

1. A vacuum cleaner including: a main body in which a suction motor for generating suction force is disposed; a dust collection unit detachably mounted on the cleaner main body and defining a 5 dust storing portion; a compression member for compressing dust stored in the dust storing portion; a compression motor for driving the compression member; a mode selection unit for selecting an operational mode of the compression motor; and 10 a control unit for controlling operation of the compression motor in accordance with the selected mode.

2. The vacuum cleaner according to claim 1, wherein the compression motor operates after a predetermined time has elapsed after the suction motor operates.

3. The vacuum cleaner according to claim 1, wherein the operational mode of the 15 compression motor includes a first operational mode where the compression motor continuously operates and a second operational mode where the compression motor operates at predetermined intervals,

4. The vacuum cleaner according to claim 3, further including a stationary member that is formed in the dust storing portion to compress the dust by associating with the 20 compressing member, wherein the compression member is stopped for a predetermined time at a position adjacent to the stationary member in the second mode.

5. The vacuum cleaner according to claim 1, further including a dust amount display unit for displaying a current amount of the dust compressed in the dust storing portion.

6. The vacuum cleaner according to claim 5, wherein an amount of the dust stored in 25 the dust storing portion is determined in accordance with a moving range of the compression member. 23

7. The vacuum cleaner according to claim 6, wherein the moving range of the compression member is determined in accordance with a moving time of the compression member or the number of rotation of the compression motor.

8. The vacuum cleaner according to claim 5, wherein, when the amount of the dust 5 compressed in the dust storing portion is greater than a reference amount, an empty signal is displayed.

9. The vacuum cleaner according to claim 1, further including a malfunction display unit for displaying malfunction of the compression member.

10. A vacuum cleaner including: 10 a main body in which a suction motor for generating suction force is disposed; a dust collection unit detachably mounted on the cleaner main body and defining a dust storing portion; at least one compression member for compressing dust stored in the dust storing portion; 15 a driving unit for driving the compression member; a control unit for determining if the compression member malfunctions; and a signal display unit for displaying a malfunction signal of the compression member.

11. The vacuum cleaner according to claim 10, further including a micro switch that 20 are selectively turned on and off in accordance with rotation of the compression member, and a counter unit for detecting an on/off time of the micro switch.

12. The vacuum cleaner according to claim 10, wherein the compression member compresses the dust while reciprocally rotating with reference to a reference position and the determination of the malfunction of the compression member is realized by comparing 25 reciprocation rotating times of the compression member with limit times.

13. The vacuum cleaner according to claim 12, wherein the reference position is a position when the micro switch is turned on or off. 24

14. The vacuum cleaner according to claim 10, wherein the driving unit stops operating when the compression member malfunctions.

15. The vacuum cleaner according to claim 10, wherein the suction motor stops operating when the compression member malfunctions. 5

16. The vacuum cleaner according to claim 10, further including a dust amount displaying unit for displaying an amount of the dust compressed in the dust collection unit, wherein the control unit determines the amount of the dust with reference to a moving range of the compression member.

17. A method of controlling a vacuum cleaner, including: 10 storing dust in a dust storing portion by operation of a suction motor; measuring an operation time of the suction motor; and operating a compression motor for driving a compression member compressing the dust stored in the dust storing portion when the operation time of the suction motor is greater than a preset time. 15

18. The method according to claim 17, wherein the compression motor rotates in opposite directions and continuously operates.

19. The method according to claim 17, wherein the compression motor operates at a predetermined time interval.

20. The method according to claim 17, wherein, when the suction motor stops 20 operating, the compression motor stops operating.

21. A vacuum cleaner substantially as herein before described with reference to the accompanying drawings. 25

22. A method of controlling a vacuum cleaner substantially as herein before described with reference to the accompanying drawings. LG ELECTRONICS INC WATERMARK PATENT & TRADE MARK ATTORNEYS P32831AU00