Abstract:
A strip-shaped emitter electrode including at least one emission edge extending along the length of such emitter electrode. When the strip-shaped emitter electrode is coupled to a voltage supply, current or an electrical charge at the emission edge ionizes the air and generates corona discharge, resulting in ion production. Erosion occurs at the emission edge such that the lifespan of the strip emitter electrode is dependent, at least in part, on the width of the strip emitter electrode.

Description:
PRIORITY CLAIM  
       [0001]     This application claims priority to, and is a continuation in part of, pending U.S. patent application Ser. No. 11/694,281, filed Mar. 30, 2007, which is a continuation in part of pending U.S. patent application Ser. No. 11/007,734, filed Dec. 8, 2004, which is a continuation of U.S. patent application Ser. No. 10/717,420, filed Nov. 19, 2003, now abandoned, which claimed priority to U.S. Provisional Patent Application No. 60/500,437, filed Sep. 4, 2003, now expired, all of which are fully incorporated herein by reference.  
       CROSS REFERENCE TO RELATED APPLICATIONS  
       [0002]     This application relates to the following commonly-owned co-pending patent applications:  
                                                       U.S. Patent                   Appln. No.   Filed   Docket No.                           90/007,276   Oct. 29, 2004   112440-068           11/041,926   Jan. 21, 2005   112440-072           11/091,243   Mar. 28, 2005   112440-352           11/062,057   Feb. 18, 2005   112440-441           11/071,779   Mar. 3, 2005   112440-702           10/994,869   Nov. 22, 2004   112440-703           11/007,556   Dec. 8, 2004   112440-709           10/074,209   Feb. 12, 2002   112440-727           10/685,182   Oct. 14, 2003   112440-743           10/944,016   Sep. 17, 2004   112440-744           10/795,934   Mar. 8, 2004   112440-761           10/435,289   May 9, 2003   112440-762           11/064,797   Feb. 24, 2005   112440-769           11/003,671   Dec. 3, 2004   112440-774           11/003,035   Dec. 3, 2004   112440-775           11/007,395   Dec. 8, 2004   112440-776           10/876,495   Jun. 25, 2004   112440-783           10/809,923   Mar. 25, 2004   112440-784           11/004,397   Dec. 3, 2004   112440-798           10/895,799   Jul. 21, 2004   112440-799           10/642,927   Aug. 18, 2003   112440-803           11/823,346   Apr. 12, 2004   112440-804           10/662,591   Sep. 15, 2003   112440-805           11/061,967   Feb. 18, 2005   112440-806           11/150,046   Jun. 10, 2005   112440-848           11/188,448   Jul. 25, 2005   112440-877           11/188,478   Jul. 25, 2005   112440-878           11/293,538   Dec. 2, 2005   112440-932           11/457,396   Jul. 13, 2006   112440-966           11/464,139   Aug. 11, 2006   112440-969           11/694,281   Mar. 30, 2007   112440-1010                      
 
       INCORPORATION BY REFERENCE  
       [0003]     The contents of the following patent applications and issued patents are fully incorporated herein by reference:  
                                           U.S. Patent                   Appln. No.   Filed   U.S. Pat. No.   Docket No.                   90/007,276   Oct. 29, 2004       112440-68       09/419,720   Oct. 14, 1999   6,504,308   112440-68US2       11/041,926   Jan. 21, 2005       112440-72       09/231,917   Jan. 14, 1999   6,125,636   112440-344       11/091,243   Mar. 28, 2005       112440-352       10/978,891   Nov. 1, 2004       112440-355       11/087,969   Mar. 23, 2005   7,056,370   112440-361       09/197,131   Nov. 20, 1998   6,585,935   112440-381       08/924,580   Sep. 5, 1997   5,802,865   112440-397       09/148,843   Sep. 4, 1998   6,189,327   112440-400       09/232,196   Jan. 14, 1999   6,163,098   112440-407       10/454,132   Jun. 4, 2003   6,827,088   112440-408       09/721,055   Nov. 22, 2000   6,640,049   112440-409       10/405,193   Apr. 1, 2003       112440-410       09/669,253   Sep. 25, 2000   6,632,407   112440-414       09/249,375   Feb. 12, 1999   6,312,507   112440-416       09/742,814   Dec. 19, 2000   6,672,315   112440-417       09/415,576   Oct. 8, 1999   6,182,671   112440-418       09/344,516   Jun. 25, 1999   6,152,146   112440-419       09/163,024   Sep. 29, 1998   5,975,090   112440-420       11/062,057   Feb. 18, 2005       112440-441       10/188,668   Jul. 2, 2002   6,588,434   112440-501       10/815,230   Mar. 30, 2004   6,953,556   112440-528       11/003,516   Dec. 3, 2004       112440-701       11/071,779   Mar. 3, 2005       112440-702       10/994,869   Nov. 22, 2004       112440-703       11/007,556   Dec. 8, 2004       112440-709       11/003,894   Dec. 3, 2004       112440-710       10/661,988   Sep. 12, 2003   7,097,695   112440-712       10/774,579   Feb. 9, 2004   7,077,890   112440-714       09/730,499   Dec. 5, 2000   6,713,026   112440-715       10/156,158   May 28, 2002   6,863,869   112440-716       09/186,471   Nov. 5, 1998   6,176,977   112440-717       11/003,752   Dec. 3, 2004       112440-721       10/835,743   Apr. 30, 2004   6,908,501   112440-722       10/791,561   Mar. 2, 2004       112440-723       10/658,721   Sep. 9, 2003   6,896,853   112440-724       11/006,344   Dec. 7, 2004       112440-726       10/074,209   Feb. 12, 2002       112440-727       10/023,460   Dec. 13, 2001       112440-728       10/379,966   Mar. 5, 2003       112440-742       10/685,182   Oct. 14, 2003       112440-743       10/944,016   Sep. 17, 2004       112440-744       10/074,096   Feb. 12, 2002   6,974,560   112440-749       10/074,347   Feb. 12, 2002   6,911,186   112440-750       10/795,934   Mar. 8, 2004       112440-761       10/435,289   May 9, 2003       112440-762       09/774,198   Jan. 29, 2001   6,544,485   112440-763       11/064,797   Feb. 24, 2005       112440-769       11/003,034   Dec. 3, 2004       112440-772       11/003,671   Dec. 3, 2004       112440-774       11/003,035   Dec. 3, 2004       112440-775       11/007,395   Dec. 8, 2004       112440-776       10/074,827   Feb. 12, 2002       112440-779       10/876,495   Jun. 25, 2004       112440-783       10/809,923   Mar. 25, 2004       112440-784       11/062,173   Feb. 18, 2005       112440-788       10/074,082   Feb. 12, 2002   6,958,134   112440-789       10/278,193   Oct. 21, 2002   6,749,667   112440-793       09/924,600   Aug. 8, 2001   6,709,484   112440-794       09/564,960   May 4, 2000   6,350,417   112440-795       10/806,293   Mar. 22, 2004   6,972,057   112440-796       11/004,397   Dec. 3, 2004       112440-798       10/895,799   Jul. 21, 2004       112440-799       10/625,401   Jul. 23, 2003   6,984,987   112440-802       10/642,927   Aug. 18, 2003       112440-803       11/823,346   Apr. 12, 2004       112440-804       10/662,591   Sep. 15, 2003       112440-805       11/061,967   Feb. 18, 2005       112440-806       11/150,046   Jun. 10, 2005       112440-848       11/188,448   Jul. 25, 2005       112440-877       11/188,478   Jul. 25, 2005       112440-878       60/777,943   Feb. 25, 2006       112440-897       11/293,538   Dec. 2, 2005       112440-932       11/338,974   Jan. 25, 2006       112440-941       10/794,526   Mar. 4, 2004   7,014,686   112440-949       10/267,006   Oct. 8, 2002   6,899,745   112440-949DIV       11/457,396   Jul. 13, 2006       112440-966       11/464,139   Aug. 11, 2006       112440-969       10/168,723   Jun. 21, 2002   6,897,617   112440-975       10/168,724   Jun. 21, 2002   6,603,268   112440-978                  
 
     
    
     BACKGROUND  
       [0004]     Existing wire emitter electrodes (referred to as “Prior Art Wire Emitter(s)”) ionize the air and generate corona discharge at levels proportionate to the current running through the electrode. Such electrodes are operatively coupled to a voltage supply which enables such current flow. The amount of ionized particles and corona discharge generated is a function of the emitter current. The higher the emitter current, the more air is ionized and the greater the corona discharge.  
         [0005]     Ozone production can be a byproduct of corona discharge if certain conditions are present. This ionization process can cause oxygen molecules (O 2 ) to split in the air. The split molecules seek stability and attach themselves to other oxygen molecules (O 2 ), forming ozone (O 3 ). Inhaling excess amounts of ozone can be undesirable and even harmful depending upon the conditions present in a given environment. Ozone generation for a given Prior Art Wire Emitter length at normal room humidity, temperature and pressure can be a function of the material of the wire, the emitter current and the diameter of the wire. For a given emitter current and material, the smaller the diameter of the wire, the less ozone is produced. One disadvantage to small diameter wires is that they tend to wear down at a relatively high rate.  
         [0006]     Accordingly, there is a need to overcome or otherwise reduce the disadvantages described above. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0007]      FIG. 1A  is a perspective view of a Prior Art Wire Emitter.  
         [0008]      FIG. 1B  is a perspective view of one embodiment of a strip emitter electrode, as described below.  
         [0009]      FIG. 1C  is an enlarged, perspective view of one embodiment of a strip emitter electrode, as described below.  
         [0010]      FIG. 2  is a graph indicating ozone production of an air treatment apparatus using one embodiment of a strip emitter electrode compared to a Prior Art Wire Emitter electrode used to generate the same emitter current.  
         [0011]      FIG. 3  is a front perspective view of one embodiment of an air treatment apparatus which includes the strip emitter electrode described below. 
     
    
     DETAILED DESCRIPTION  
       [0012]      FIG. 1A  illustrates a perspective view of a Prior Art Wire Emitter. The use of a strip emitter electrode  10 , as illustrated in  FIGS. 1B and 1C , overcomes or reduces the problems related to Prior Art Wire Emitters by exhibiting a longer structural lifetime and generating desired levels of corona discharge associated with acceptable amounts of ozone.  
         [0013]     Referring now to  FIGS. 1B and 1C , in one embodiment, the strip emitter electrode  10  includes a rectangular body having a length  12 , a width  14 , a thickness  16 , and emission edges  18   a  and  18   b . Edges  18   a  and  18   b  are defined by the length  12  and the thickness  16 , and edges  18   a  and  18   b  extend along the length  12  of the strip emitter electrode  10 . When a current flows through the strip emitter electrode  10 , corona current concentrates on at least one of edges  18   a  and  18   b . Accordingly, any erosion of the strip emitter electrode  10  caused by corona current progresses from the respective edge  18   a  or  18   b  of the strip emitter electrode  10  inward along the width  14 . This enables strip emitter electrode  10  to perform the ionic emission function for a relatively long period of time. The concentration of corona at at least one of edges  18   a  and  18   b  of the strip emitter electrode  10  results in ionization similar to that resulting from corona emitted from a thin wire within corresponding levels of ozone generation.  
         [0014]     With continued reference to  FIG. 1C , erosion may progress inward from edge  18   a . For example: after one period of operation, the edge  18   a  deteriorates and recedes to line  20   a ; after a longer period of operation, the edge  18   a  deteriorates and recedes to line  20   b ; and after an even longer period of time, the edge  18   a  deteriorates and recedes to line  20   c . In on example, this process continues until the entire width  14  of the strip emitter electrode is depleted or disintegrated. The lifespan of the strip emitter electrode  10  is a function, in part, of the width  14  of the strip emitter electrode  10 . All other variables being equal, in this example, the greater the width  14 , the longer the lifespan of a strip emitter electrode  10 . If edge  18   a  of the strip emitter electrode  10  were the only edge eroding due to current concentration, the life of the strip emitter electrode  10  would terminate approximately when the erosion reaches edge  18   b . If both edges  18   a  and  18   b  are eroding due to current concentration, the life of the strip emitter electrode  10  would terminate approximately when the erosions lines extending inward from respective edges  18   a  and  18   b  converge.  
         [0015]     Such a strip emitter electrode  10  may have any suitable rectangular geometry and have any suitable length  12 , width  14  and thickness  16 . For example, the width  14  of the strip emitter electrode  10  could extend from 0.1 mm upward. Additionally, the thickness  16  of the strip emitter electrode  10  could range from 0.01 mm to 0.15 mm. In one tested embodiment, the width  14  of the strip emitter electrode  10  is approximately 2.3 mm, and the thickness  16  of the strip emitter electrode  10  is approximately 0.02 mm. Additionally, the strip emitter electrode  10  may be composed of any suitable material. In one embodiment, the strip emitter electrode  10  is composed of molybdenum. In the illustrated and tested embodiment, the strip emitter electrode  10  has a flexible foil structure. It should be appreciated, however, that the strip emitter electrode  10  can have any suitable rigid or flexible structure, including, but not limited to: (a) a ribbon; (b) a foil; (c) a tape; (d) a belt or band; or (e) any other suitable relatively thin structure.  
         [0016]     Referring now to Table 1 below, to demonstrate the relationship between Prior Art Wire Emitter diameter and ozone generation, consider a tungsten Prior Art Wire Emitter electrode between 0.1 and 0.12 mm in diameter. The following table illustrates the ozone production of such a Prior Art Wire Emitter electrode at a designated current as a function of the diameter of the wire.  
                                         TABLE 1                                   Wire Diameter, mm   O3, mg/hr                                        0.12   2.62           0.1   2.23           0.08   1.96                      
 
         [0017]     As illustrated in Table 1, ozone generation resulting from such Prior Art Wire Emitter decreases with wire diameter. However, as described above, smaller diameter wires may not have a sufficient lifespan for practical application, breaking and requiring replacement because corona current erodes the Prior Art Wire Emitters.  
         [0018]     In one test, ozone generation of an air treatment apparatus including Prior Art Wire Emitter electrodes was measured as a function of current at designated currents. Then, ozone generation of the same air treatment apparatus including a plurality of the strip emitter electrodes  10  was measured at the same current. Then, the two sets of results where compared, as illustrated in Table 2 below. For this test, Prior Art Wire Emitters having a diameter of 0.12 mm were used. Molybdenum strip emitter electrodes, having a width of 2.3 mm and a thickness of 0.02 mm, were used. In this particular test, both the Prior Art Wire Emitters and such strip emitter electrodes  10  were operated in an air treatment apparatus which also includes collector and driver electrodes. In this test, the emitter electrodes and the collector electrodes were operatively coupled to a voltage generator. Table 2 below and  FIG. 2  include relevant test data.  
                                     TABLE 2                           O3, mg/hr   O3, mg/hr           Strip Emitter   Prior Art Wire Emitter       I, μA   Electrodes   Electrodes                                200   1.8   2.8       400   3.7   5.5       600   5.5   8                  
 
         [0019]     As illustrated in Table 2 and  FIG. 2 , operating at the same designated currents, the use of the strip emitter electrodes resulted in less ozone generation than the use of the Prior Art Wire Emitter electrodes.  
         [0020]     Performance of the air treatment apparatus used in this test was also measured in terms of Clean Air Delivery Rate (“CADR”). CADR is the amount of clean air measured in cubic feet per minute that an air cleaner delivers to a room. The performance of the air treatment apparatus used in this particular test, independent of ozone generation differentiation, was substantially similar when using the strip emitter electrodes  10 , as opposed to the Prior Art Wire Emitters. This is illustrated by the sample estimated CADR results of Table 3 below. The “High,” “Med,” “Low,” and “Quiet” designators in Table 3 refer to various operating modes of the air treatment apparatus from which these results were measured. While performing at similar CADR levels, the ozone generation using strip emitter electrodes  10  was significantly lower.  
                               TABLE 3                                       CADR                   (Prior Art Wire Emitter   CADR           Mode   Electrode)   (Strip Emitter Electrode)                           High   155.4   174.3           Medium   137.6   138.6           Low   124.3   135.2           Quiet   100.6   110.3                      
 
         [0021]     It should be appreciated that although the strip emitter electrode  10  described in this application was tested in an air treatment apparatus including a collector electrode in the foregoing example, the strip emitter electrode  10  may be incorporated into a variety of air treatment devices including, without limitation, various electrode configurations, pure ionizers (such as a strip emitter electrode which causes ions to flow toward any suitable grounded object), or any other suitable device. For example, the strip emitter electrode could be utilized in air treatment devices including at least one of: (a) emitter electrodes; (b) collector electrodes; (c) electrodes interstitially located between the collector electrodes (driver electrodes); and (d) additional suitable electrodes. An example of such a device is shown in  FIG. 3 , which illustrates an air treatment apparatus including an elongated housing which supports the internal components of the air treatment apparatus. In this illustration, the air treatment apparatus could include an electrode assembly with at least one of the strip emitter electrodes  10  illustrated in  FIGS. 1B and 1C . Though the housing shown has an elongated shape, it should be understood that other shapes for the air treatment apparatus are suitable. In one embodiment, such air treatment apparatus includes a control panel for turning on and off the air treatment apparatus, or for changing operating settings (e.g., low, medium, high or quiet). In operation, the air treatment apparatus draws surrounding air into the apparatus through the front air inlet. The front air inlet can include a plurality of fins, slats or louvers that facilitate air flow into the apparatus. An electrode assembly in the air treatment apparatus cleans or removes particles from the air as air flows through the apparatus.  
         [0022]     The apparatus can remove dust particles and other airborne particles from the air, including particles which cause odor, as well as particles present in smoke and other gases. Also, the apparatus can condition and treat the air by removing or altering chemicals present in the air. Furthermore, the apparatus can collect and kill airborne pathogens and micro-organisms through the effect of the electric field produced by the electrode assembly and cold plasma of corona discharge. Once cleaned or otherwise treated, the air exits the apparatus through the rear air outlet. Similar to the front air inlet, the rear air outlet can include a plurality of fins, slats or louvers that facilitate air flow out of the apparatus.  
         [0023]     In one embodiment, the strip emitter electrode  10  includes a first end and a second end, the first and second end both held by a tensioning mechanism or holder which holds the strip emitter electrode tight in a linear configuration, eliminating or reducing slack.  
         [0024]     In various embodiments, the strip emitter electrode may be either a permanent or replaceable component of an air treatment apparatus or any device. Alternatively, the strip emitter electrode may constitute a device in and of itself (i.e., a pure ionizer as described above), used with a voltage source. In such embodiment, the strip emitter electrode can be a replaceable item.  
         [0025]     Additionally, the strip emitter electrode may be fabricated in a variety of ways and by a variety of devices. For example, the strip emitter electrode could be produced as a product of: (a) a laser cutting method; (b) mechanical cutting method; (c) any combination of these methods; or (d) any suitable fabrication method like, for example, rolling. Such methods could employ a variety of cutting devices, including: (i) lasers; (ii) mechanical cutters; (iii) any combination of these devices; or (iv) any suitable device.  
         [0026]     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.