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 
     This application is a continuation in part of U.S. patent application Ser. No. 11/007,734, filed Dec. 8, 2004, now U.S. Pat. No. 7,517,505, 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. 5, 2003, now expired, all of which are fully incorporated herein by reference. This application is also a continuation in part of U.S. patent application No. 10/791,561, filed Mar. 2, 2004, now U.S. Pat. No. 7,517,503. 
     CROSS REFERENCE TO RELATED APPLICATIONS 
     This application relates to the following commonly-owned co-pending patent applications: 
     
       
         
               
               
             
           
               
                   
               
               
                 U.S. Patent 
                   
               
               
                 application Ser. No. 
                 Filed 
               
               
                   
               
             
             
               
                 90/007,276 
                 Oct. 29, 2004 
               
               
                 11/041,926 
                 Jan. 21, 2005 
               
               
                 11/091,243 
                 Mar. 28, 2005 
               
               
                 11/062,057 
                 Feb. 18, 2005 
               
               
                 11/071,779 
                 Mar. 3, 2005 
               
               
                 10/994,869 
                 Nov. 22, 2004 
               
               
                 11/007,556 
                 Dec. 8, 2004 
               
               
                 10/074,209 
                 Feb. 12, 2002 
               
               
                 10/685,182 
                 Oct. 14, 2003 
               
               
                 10/944,016 
                 Sep. 17, 2004 
               
               
                 10/795,934 
                 Mar. 8, 2004 
               
               
                 10/435,289 
                 May 9, 2003 
               
               
                 11/064,797 
                 Feb. 24, 2005 
               
               
                 11/003,671 
                 Dec. 3, 2004 
               
               
                 11/003,035 
                 Dec. 3, 2004 
               
               
                 11/007,395 
                 Dec. 8, 2004 
               
               
                 10/876,495 
                 Jun. 25, 2004 
               
               
                 10/809,923 
                 Mar. 25, 2004 
               
               
                 11/004,397 
                 Dec. 3, 2004 
               
               
                 10/895,799 
                 Jul. 21, 2004 
               
               
                 10/642,927 
                 Aug. 18, 2003 
               
               
                 11/823,346 
                 Apr. 12, 2004 
               
               
                 10/662,591 
                 Sep. 15, 2003 
               
               
                 11/061,967 
                 Feb. 18, 2005 
               
               
                 11/150,046 
                 Jun. 10, 2005 
               
               
                 11/188,448 
                 Jul. 25, 2005 
               
               
                 11/188,478 
                 Jul. 25, 2005 
               
               
                 11/293,538 
                 Dec. 2, 2005 
               
               
                 11/457,396 
                 Jul. 13, 2006 
               
               
                 11/464,139 
                 Aug. 11, 2006 
               
               
                 11/694,281 
                 Mar. 30, 2007 
               
               
                   
               
             
          
         
       
     
     INCORPORATION BY REFERENCE 
     The contents of the following patent applications and issued patents are fully incorporated herein by reference: 
     
       
         
               
               
               
             
           
               
                   
               
               
                 U.S. Patent 
                   
                   
               
               
                 application Ser. No. 
                 Filed 
                 U.S. Pat. No. 
               
               
                   
               
             
             
               
                 90/007,276 
                 Oct. 29, 2004 
                   
               
               
                 09/419,720 
                 Oct. 14, 1999 
                 6,504,308 
               
               
                 11/041,926 
                 Jan. 21, 2005 
               
               
                 09/231,917 
                 Jan. 14, 1999 
                 6,125,636 
               
               
                 11/091,243 
                 Mar. 28, 2005 
               
               
                 10/978,891 
                 Nov. 1, 2004 
               
               
                 11/087,969 
                 Mar. 23, 2005 
                 7,056,370 
               
               
                 09/197,131 
                 Nov. 20, 1998 
                 6,585,935 
               
               
                 08/924,580 
                 Sep. 5, 1997 
                 5,802,865 
               
               
                 09/148,843 
                 Sep. 4, 1998 
                 6,189,327 
               
               
                 09/232,196 
                 Jan. 14, 1999 
                 6,163,098 
               
               
                 10/454,132 
                 Jun. 4, 2003 
                 6,827,088 
               
               
                 09/721,055 
                 Nov. 22, 2000 
                 6,640,049 
               
               
                 10/405,193 
                 Apr. 1, 2003 
                   
               
               
                 09/669,253 
                 Sep. 25, 2000 
                 6,632,407 
               
               
                 09/249,375 
                 Feb. 12, 1999 
                 6,312,507 
               
               
                 09/742,814 
                 Dec. 19, 2000 
                 6,672,315 
               
               
                 09/415,576 
                 Oct. 8, 1999 
                 6,182,671 
               
               
                 09/344,516 
                 Jun. 25, 1999 
                 6,152,146 
               
               
                 09/163,024 
                 Sep. 29, 1998 
                 5,975,090 
               
               
                 11/062,057 
                 Feb. 18, 2005 
                   
               
               
                 10/188,668 
                 Jul. 2, 2002 
                 6,588,434 
               
               
                 10/815,230 
                 Mar. 30, 2004 
                 6,953,556 
               
               
                 11/003,516 
                 Dec. 3, 2004 
               
               
                 11/071,779 
                 Mar. 3, 2005 
               
               
                 10/994,869 
                 Nov. 22, 2004 
               
               
                 11/007,556 
                 Dec. 8, 2004 
               
               
                 11/003,894 
                 Dec. 3, 2004 
               
               
                 10/661,988 
                 Sep. 12, 2003 
                 7,097,695 
               
               
                 10/774,579 
                 Feb. 9, 2004 
                 7,077,890 
               
               
                 09/730,499 
                 Dec. 5, 2000 
                 6,713,026 
               
               
                 10/156,158 
                 May 28, 2002 
                 6,863,869 
               
               
                 09/186,471 
                 Nov. 5, 1998 
                 6,176,977 
               
               
                 11/003,752 
                 Dec. 3, 2004 
               
               
                 10/835,743 
                 Apr. 30, 2004 
                 6,908,501 
               
               
                 10/791,561 
                 Mar. 2, 2004 
               
               
                 10/658,721 
                 Sep. 9, 2003 
                 6,896,853 
               
               
                 11/006,344 
                 Dec. 7, 2004 
               
               
                 10/074,209 
                 Feb. 12, 2002 
               
               
                 10/023,460 
                 Dec. 13, 2001 
               
               
                 10/379,966 
                 Mar. 5, 2003 
               
               
                 10/685,182 
                 Oct. 14, 2003 
               
               
                 10/944,016 
                 Sep. 17, 2004 
               
               
                 10/074,096 
                 Feb. 12, 2002 
                 6,974,560 
               
               
                 10/074,347 
                 Feb. 12, 2002 
                 6,911,186 
               
               
                 10/795,934 
                 Mar. 8, 2004 
               
               
                 10/435,289 
                 May 9, 2003 
               
               
                 09/774,198 
                 Jan. 29, 2001 
                 6,544,485 
               
               
                 11/064,797 
                 Feb. 24, 2005 
               
               
                 11/003,034 
                 Dec. 3, 2004 
               
               
                 11/003,671 
                 Dec. 3, 2004 
               
               
                 11/003,035 
                 Dec. 3, 2004 
               
               
                 11/007,395 
                 Dec. 8, 2004 
               
               
                 10/074,827 
                 Feb. 12, 2002 
               
               
                 10/876,495 
                 Jun. 25, 2004 
               
               
                 10/809,923 
                 Mar. 25, 2004 
               
               
                 11/062,173 
                 Feb. 18, 2005 
               
               
                 10/074,082 
                 Feb. 12, 2002 
                 6,958,134 
               
               
                 10/278,193 
                 Oct. 21, 2002 
                 6,749,667 
               
               
                 09/924,600 
                 Aug. 8, 2001 
                 6,709,484 
               
               
                 09/564,960 
                 May 4, 2000 
                 6,350,417 
               
               
                 10/806,293 
                 Mar. 22, 2004 
                 6,972,057 
               
               
                 11/004,397 
                 Dec. 3, 2004 
               
               
                 10/895,799 
                 Jul. 21, 2004 
               
               
                 10/625,401 
                 Jul. 23, 2003 
                 6,984,987 
               
               
                 10/642,927 
                 Aug. 18, 2003 
               
               
                 11/823,346 
                 Apr. 12, 2004 
               
               
                 10/662,591 
                 Sep. 15, 2003 
               
               
                 11/061,967 
                 Feb. 18, 2005 
               
               
                 11/150,046 
                 Jun. 10, 2005 
               
               
                 11/188,448 
                 Jul. 25, 2005 
               
               
                 11/188,478 
                 Jul. 25, 2005 
               
               
                 60/777,943 
                 Feb. 25, 2006 
               
               
                 11/293,538 
                 Dec. 2, 2005 
               
               
                 11/338,974 
                 Jan. 25, 2006 
               
               
                 10/794,526 
                 Mar. 4, 2004 
                 7,014,686 
               
               
                 10/267,006 
                 Oct. 8, 2002 
                 6,899,745 
               
               
                 11/457,396 
                 Jul. 13, 2006 
               
               
                 11/464,139 
                 Aug. 11, 2006 
               
               
                 10/168,723 
                 Jun. 21, 2002 
                 6,897,617 
               
               
                 10/168,724 
                 Jun. 21, 2002 
                 6,603,268 
               
               
                   
               
             
          
         
       
     
    
    
     BACKGROUND 
     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. 
     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. 
     Accordingly, there is a need to overcome or otherwise reduce the disadvantages described above. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  is a perspective view of a Prior Art Wire Emitter. 
         FIG. 1B  is a perspective view of one embodiment of a strip emitter electrode, as described below. 
         FIG. 1C  is an enlarged, perspective view of one embodiment of a strip emitter electrode, as described below. 
         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. 
         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 
       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. 
     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. 
     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. 
     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. 
     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 
               
               
                   
                   
               
             
          
         
       
     
     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. 
     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 
               
               
                   
               
             
          
         
       
     
     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. 
     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 
               
               
                   
                   
               
             
          
         
       
     
     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. 
     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. 
     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. 
     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. 
     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. 
     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.