Abstract:
There is provided an air cleaner which includes an air inlet, a first electromagnetic wave shield disposed adjacent to the air inlet, an electrical means for air induction, a second electromagnetic wave shield disposed adjacent to the air outlet, and a grounding means. The electrical means for air induction draws in air through the first electromagnetic wave shield and exhausts it towards the air outlet and through the second electromagnetic the wave shield. The grounding means discharges current induced in the first and second electromagnetic wave shields. There is also provided a method describing the operation of an embodiment of the air cleaner.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to the Korean Application No. 20-2002-37714, filed on Dec. 18, 2002, the content of which is hereby incorporated by reference herein in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to an air cleaner and, more particularly, to an air cleaner having a grounding function.  
         BACKGROUND OF THE INVENTION  
         [0003]    There has been a necessity for countering electromagnetic waves produced by home appliances. It is well known in the art that electromagnetic waves and resulting fields can pose a health hazard to human beings and may cause disruption at the cellular levels. Electromagnetic waves, hereinafter also referred to as electric field noise, are emitted by a driving current during operation of electrical home appliances. Electrical home appliances, such as televisions, stereo equipment, and electrical beds and mats, emit quantifiable amounts of electromagnetic waves. Due to the risks of exposure to electromagnetic waves, measures for countering electric field noise should be required for most, if not all, home appliances installed in the living space. The most common countering measure is to ground the circuits of the electrical home appliance, thereby shielding against electromagnetic waves. By grounding such appliances, leakage currents generated by the appliances are bypassed to ground, further preventing accidental electric shocks.  
           [0004]    Inventions designed to discharge electromagnetic waves by using a grounding potential are well known. For example, Korean Utility Model Registration No. 239143 discloses a carbon polymer heater for mats, which is designed to attenuate electromagnetic waves by facing primary and secondary windings. In Korean Utility Model Registration No. 251672, a thermostat heater is described and includes an inner winding heater, a nylon thermister, a winding under a nylon layer, a winding on a nylon layer, and an outer winding to discharge electromagnetic waves emitted from the heater to an external electric field. Another example is disclosed in Korean Patent No. 341280, which teaches an apparatus for shielding electromagnetic waves of thermo-electric mats by including a spiral inner lead wire and a spiral outer lead wire which are connected to one common ground.  
           [0005]    Further examples include Korean Utility Model Registration No. 255095, which describes a temperature-sensitive heater formed in a structure of three layers of windings. The structure includes an exothermic winding, a current supply winding connected to one side of a nylon thermister, and a temperature detection winding connected to the other side of the thermister. This configuration results in providing electromagnetic waves to a neutral electric field of an alternating current (AC). Similarly, in Korean Patent Application No. 2002-0019148, an automatic grounding switching circuit, that is designed to allow grounding using a neutral potential in both the one-line grounding mode and the neutral grounding mode of an AC power source, is provided. With respect to the aforementioned inventions described above and in the previous paragraph, parts emitting electromagnetic waves are covered with organic materials for shielding purposes and are connected to grounding means to discharge the electromagnetic waves.  
           [0006]    In FIG. 1, the common home appliance of a conventional air cleaner is shown. The conventional air cleaner  100  includes a suction chamber  110 , an intermediate chamber  120 , and a filtering chamber  130 . An air blower  112  is disposed in the suction chamber  110 . In operating the air cleaner  100 , external air is filtered while flowing into the intermediate chamber  120  through a first filter  111  and then through an air inlet  121 . The air flow is aided by the suction created by the air blower  112 . From the intermediate chamber  120 , the air then passes through an air outlet  131  and into the filtering chamber  130 . The air is subsequently filtered through second and third filters  132  and  133  and emitted to an external space through a grill  134 .  
           [0007]    Generally, the first filter  111  is a sponge filter, the second filter  132  is a paper filter, and the third filter  133  is a copper filter. In such air cleaners as shown in FIG. 1, the cabinet housing the air cleaner  100  shields some of the electromagnetic waves. However, some the electric field noise is also discharged in the external space from the air blower  112  via the air inlet  121 , the air outlet  131 , and the grill  134 . In conventional cylindrically shaped air cleaners, shown in FIGS. 2 and 3, an air blower  210  and a ring-shaped filtering chamber  217  are formed in an air cleaner  200 . External air is filtered while flowing into an air blower  210  through first, second and third filters  211 ,  212  and  213 . The filtered air then passes through an inlet  214  and is discharged into external space through an air outlet  215  and a grill  216 . Similar to the air cleaner of FIG. 1, electromagnetic waves generated by the operation of the air blower  210  in FIGS. 2 and 3 are discharged into the external space through the air outlet  215 .  
           [0008]    [0008]FIG. 4 shows a conventional grounding circuit diagram of a home appliance. In FIG. 4, a grounding selection circuit  300  receives an AC voltage H of 220 volts (V) and of a frequency of 60 Hz. The current H is supplied to an electromagnetic device M, such as the motor of a home appliance, for operation. An ozone discharge tube  600  and negatively charged ion tip  700 , commonly provided in electrical home appliances, supply direct current through a rectifier  400  and an ignition timer  500  for a preset time. A grounding connection GC of the home appliance is connected to the grounding component of the ground selection circuit  300 , that is, a neutral potential point N or a ground G.  
           [0009]    As shown by FIGS.  1 - 4 , there is a need to further enhance the shielding effects of common home appliances such as air cleaners from electric field noise.  
         SUMMARY OF THE INVENTION  
         [0010]    Accordingly, the present invention is directed to an improved air cleaning method and apparatus that substantially obviates one or more problems due to the limitations and disadvantages of the related art. It is, therefore, an object of the present invention to provide an air cleaning method and apparatus that effectively shields electromagnetic waves discharged from the air cleaner and discharges current induced in electromagnetic wave shields to a ground or grounding component.  
           [0011]    In order to achieve the aforementioned object of the present invention, there is provided an air cleaner which comprises an air inlet, a first electromagnetic wave shield disposed adjacent to the air inlet, an electrical means for air induction, a second electromagnetic wave shield disposed adjacent to the air outlet, and a grounding means. The electrical means for air induction draws in air through the first electromagnetic wave shield and exhausts it towards the air outlet and through the second electromagnetic the wave shield. The grounding means discharges current induced in the first and second electromagnetic wave shields.  
           [0012]    According to one aspect of the present invention, the first and second electromagnetic wave shields comprise (10) copper mesh. The air cleaner also may comprise a cabinet made of electromagnetic wave shielding material to house the air cleaner. Further, the air cleaner may comprise an ozone discharge tube and/or a negatively charged ion tip.  
           [0013]    According to another aspect of the present invention, the grounding means may be a grounding component of a ground selection circuit connected to a power source providing an alternating current. Alternatively, the grounding means may be a ground connected to an electrical outlet supplying a current via a plug.  
           [0014]    In another embodiment of the present invention, the air cleaner may have a cylindrical shape.  
           [0015]    There is also provided a method of air cleaning, which comprises the following steps: (1) operating an electrical air inducing means to draw in air; (2) discharging leakage current generated by the operation of the air inducing means to ground; (3) drawing in air through an air inlet, wherein the air passes through a first electromagnetic wave shield; (4) shielding the air inlet from electromagnetic waves, which are created by the operation of the electrical air inducing means, with the first electromagnetic wave shield; (4) discharging electrical current generated in the first electromagnetic wave shield by electromagnetic waves from the electrical air inducing means to ground; (5) exhausting air through an air outlet, wherein air passes through a second electromagnetic wave shield; (6) filtering air through one or more filters; (7) shielding the air outlet from electromagnetic waves, which are created by the operation of the electrical air inducing means, with the second electromagnetic wave shield; (8) discharging electrical current generated in the second electromagnetic wave shield by electromagnetic waves from the electrical air inducing means to ground; and (9) exhausting filtered air to an external space.  
           [0016]    Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. Therefore, it is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide a further explanation of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0018]    [0018]FIG. 1 is a sectional view of a conventional air cleaner;  
         [0019]    [0019]FIG. 2 is a perspective view of a conventional cylindrically shaped air cleaner;  
         [0020]    [0020]FIG. 3 is a sectional view of the conventional cylindrically shaped air cleaner of FIG. 2;  
         [0021]    [0021]FIG. 4 is a conventional grounding circuit diagram of a conventional electrical home appliance;  
         [0022]    [0022]FIG. 5 is a sectional view of an air cleaner including electromagnetic wave shields in accordance with an embodiment of the present invention;  
         [0023]    [0023]FIGS. 6A and 6B are plan views of the electromagnetic wave shields of the air cleaner shown in FIG. 5, in accordance with an embodiment of the present invention;  
         [0024]    [0024]FIG. 7 is a sectional view of a cylindrically shaped air cleaner including electromagnetic wave shields in accordance with another embodiment of the present invention;  
         [0025]    [0025]FIGS. 8A and 8B are plan views of the electromagnetic wave shields of the air cleaner shown in FIG. 7, in accordance with an embodiment of the present invention;  
         [0026]    [0026]FIG. 9 is a grounding circuit diagram of an air cleaner in accordance with an embodiment of the present invention;  
         [0027]    [0027]FIG. 10 is a grounding circuit diagram of an air cleaner in accordance with another embodiment of the present invention; and  
         [0028]    [0028]FIG. 11 is a grounding circuit diagram of an air cleaner in accordance with another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Hereinafter, the present invention will be described with respect to the preferred embodiment illustrated in the annexed drawings.  
         [0030]    [0030]FIG. 5 is a sectional view of an air cleaner  1  including electromagnetic wave shields in accordance with an embodiment of the present invention. As shown in FIG. 5, the air cleaner  1  includes a suction chamber  10 , an intermediate chamber  20 , and a filtering chamber  30 . An air blower  12  is disposed in the suction chamber  10 . In operating the air cleaner  1 , external air is filtered while flowing into the intermediate chamber  20  through a first filter  11  and then through an air inlet  21 . The air flow is aided by the suction created by the air blower  12 . From the intermediate chamber  20 , the air then passes through an air outlet  31  and into the filtering chamber  30 . The air is subsequently filtered through second and third filters  32  and  33  and emitted to an external space through a grill  34 .  
         [0031]    Also shown in FIG. 5, a cabinet housing the air cleaner  1  is made of electromagnetic wave shielding material. A first electromagnetic wave shield  15  is disposed at the air inlet  21 . A second electromagnetic wave shield  35  is disposed in the filtering chamber  30  at the air outlet  31 , wherein the wave shield  35  preferably surrounds the inner surfaces of the top, bottom and side adjacent to the air outlet  31  of the filtering chamber  30 . The first and second electromagnetic wave shields  15  and  35 , as well as the air blower  12 , are connected to a ground  60 . An ozone discharge tube  600 , for removing odors, and a negatively charged ion tip  700 , for air purification, are arranged in the intermediate chamber  20 .  
         [0032]    [0032]FIGS. 6A and 6B illustrate the structure of the electromagnetic wave shields  15  and  35  disposed in the air cleaner  1  as shown in FIG. 5. The wave shields  15  and  35  are formed of electricity conduction nets and are formed of a (10) mesh copper net  18  and  38 , respectively. The wave shield  15  in FIG. 6A, which is surrounded by a frame  16 , is preferably inserted between the first filter  11  and the air blower  12  to shield electromagnetic waves flowing into the air inlet  21  formed behind the air blower  12 . The wave shield  35  in FIG. 6B contains space  36  for disposing the second and third filters  32  and  33  therein. Preferably, a frame  37  is attached around the (10) mesh copper net  38 .  
         [0033]    [0033]FIG. 7 is a sectional view of a cylindrically shaped air cleaner including electromagnetic wave shields in accordance with another embodiment of the present invention. As shown in FIG. 7, an air blower  40  and a ring shaped filtering chamber  40   a  are disposed in an air cleaner  4 . External air is filtered while flowing into an air blower  40  through first, second and third filters  41 ,  42  and  43 . The filtered air then passes through an inlet  44  and is discharged into external space through an air outlet  45  and a grill  46 . An ozone discharge tube  600 , for removing odors, and a negatively charged ion tip  700 , for air purification, are arranged in the air outlet  45 .  
         [0034]    In this embodiment of the present invention, electromagnetic wave shields  48  and  49  are preferably arranged along the inner circumference of the ring shaped filtering chamber  40 a and underneath the air outlet  45 , respectively. This arrangement provides for shielding electromagnetic waves generated by the air blower  40 . In FIG. 8A, the electromagnetic wave shield  48 , which has a ring shape to comport with the filtering chamber  40 a, is also latticed when viewed from the side in order to effectively discharge electromagnetic waves. FIG. 8B illustrates the wave shield  49 , which is disposed at the air outlet  45 , retains a circular shape.  
         [0035]    [0035]FIGS. 9, 10 and  11  are grounding circuit diagrams of air cleaners in accordance with embodiments of the present invention. In FIGS. 9, 10 and  11 , the shapes of the electromagnetic wave shields are illustrated on the basis of the embodiment described in FIG. 5. However, these circuit diagrams can also be applied to the embodiment shown in FIG. 7 (as well as other embodiments); therefore, FIGS. 9, 10 and  11  will described with respect to both embodiments.  
         [0036]    As shown in FIG. 9, the electromagnetic wave shield  15  or  48  is disposed at the air inlet side (as indicated by the arrow denoting air flow direction) adjacent to the air blower  12  or  40 . The electromagnetic wave shield  35  or  49  is disposed at the air outlet side and is connected to the ground  60 . Any leakage current generated by the air blower  12  or  40  is discharged to the ground  60  in order to prevent electric shock. Additionally, prior to the discharge of electromagnetic waves through the air inlet side  21  or  44 , electromagnetic waves discharged from the air blower  12  or  40  induce current in the electromagnetic wave shield  15  or  48 . Subsequently, the induced current is discharged to the ground  60 . Similarly, before the electromagnetic waves are discharged through the air outlet side  31  or  45 , electromagnetic waves induce current in the electromagnetic wave shield  38  or  49 . The induced current is then discharged to the ground  60 . Consequently, the amount of electric field noise present in the external space is reduced.  
         [0037]    In FIG. 10, a ground selection circuit  300 , which provides a grounding means, receives AC voltage H to the air blower  12  or  40  in order for operation. Should the air blower  12  or  40  generate leakage current, the current will be discharged to a grounding component, such as a neutral potential point N, through a discharge line  61  in order to prevent electric shock. Additionally, prior to the discharge of electromagnetic waves through the air inlet side  21  or  44 , electromagnetic waves discharged from the air blower  12  or  40  induce current in the electromagnetic wave shield  15  or  48 . Subsequently, the induced current is discharged to the neutral potential point N. Similarly, before the electromagnetic waves are discharged through the air outlet side  31  or  45 , electromagnetic waves induce current in the electromagnetic wave shield  38  or  49 . The induced current is then discharged to the neutral potential point N. As a result, the total amount of electromagnetic waves discharged to the external space is diminished.  
         [0038]    [0038]FIG. 11 shows a commercial AC current being supplied to the air blower  12  or  40  through a conventional wall electrical outlet  53  and a plug  52 . The air blower  12  or  40  is electrically connected to the ground  60 . The ground  60  is connected to contact terminals  54  and  55  of the electrical outlet  53  and plug  52  via a discharge line  51 . Accordingly, should the air blower  12  or  40  generate leakage current, it is discharged to the ground  60  in order to prevent electric shock. Additionally, the first magnetic wave shield  15  or  48  and the second magnetic wave shield  35  or  49  are connected to the ground  60 . Therefore, before electromagnetic waves are discharged through the air inlet  21  or  44 , electromagnetic waves discharged from the air blower  12  or  40  induce current in the first  15  or  38  and second  35  or  49  electromagnetic wave shields. The induced current is then discharged to the ground  60 . Similarly, before the electromagnetic waves are discharged through the air outlet side  31  or  45 , electromagnetic waves induce current in the electromagnetic wave shield  38  or  49 . The induced current is then discharged to the ground  60 .  
         [0039]    Accordingly, the air cleaner of the present invention reduces the amount of electrical noise in the external space by bypassing to ground or a grounding component a current induced by electromagnetic waves generated from the operation of an air blower within the air cleaner. Furthermore, leakage current created by the air blower is also bypassed to ground or a grounding component in order to prevent electric shock.  
         [0040]    Therefore, the foregoing description of the preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification and examples provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.