Abstract:
An air treatment apparatus including a plurality of electrodes coupled to a voltage generator. The air treatment apparatus has a structure defining an array of openings.

Description:
PRIORITY CLAIM  
       [0001]     This application is a continuation of, and claims priority to, U.S. patent application Ser. No. 10/895,799, filed Jul. 21, 2004 which claims priority from U.S. patent application Ser. No. 10/074,209 filed Feb. 12, 2002. The patent application Ser. No. 10/074,209 claims priority from the U.S. Provisional Patent Application No. 60/341,518, filed Sep. 13, 2001 under 35 U.S.C. 119(e). The patent application Ser. No. 10/074,209, claims priority from U.S. Provisional Patent Application No. 60/306,479, filed Jul. 18, 2001 under 35 U.S.C. 119(e). The patent application Ser. No. 10/074,209, also claims priority from, and is a continuation-in-part, of U.S. patent application Ser. No. 09/924,624, now abandoned, filed Aug. 8, 2001 which is a continuation of, and claims priority to, U.S. patent application Ser. No. 09/564,960 filed May 4, 2000, now U.S. Pat. No. 6,350,417, which is a continuation-in-part of, and claims priority to, U.S. patent application Ser. No. 09/186,471 filed Nov. 5, 1998, now U.S. Pat. No. 6,176,977. U.S. patent application Ser. No. 10/074,209 is a continuation-in-part of, and claims priority to, U.S. patent application Ser. No. 09/730,499, filed Dec. 5, 2001, now U.S. Pat. No. 6,713,026, which is a continuation of, and claims priority to, U.S. patent application Ser. No. 09/186,471 filed Nov. 5, 1998, now U.S. Pat. No. 6,176,977. All of the above are incorporated herein by reference.  
       CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0002]     This application is related to the following commonly owned applications:  
                                                       U.S. Patent Appln. No.   Filed   Docket No.                           11/188,478   Jul. 25, 2005   112440-878           10/405,193   Apr. 1, 2003   112440-410           11/071,779   Mar. 3, 2005   112440-702           10/994,869   Nov. 22, 2004   112440-703           11/003,752   Dec. 3, 2004   112440-721           10/791,561   Mar. 2, 2004   112440-723           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           11/007,734   Dec. 8, 2004   112440-773           11/003,035   Dec. 3, 2004   112440-775           11/007,395   Dec. 8, 2004   112440-776           10/809,923   Mar. 25, 2004   112440-784           11/004,397   Dec. 3, 2004   112440-798           10/895,799   Jul. 21, 2004   112440-799           10/662,591   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           11/293,538   Dec. 2, 2005   112440-932           11/338,974   Jan. 25, 2006   112440-941           11/457,396   Jul. 13, 2006   112440-966           11/464,139   Aug. 11, 2006   112440-969           90/007,276   Oct. 29, 2004   112440-68           11/041,926   Jan. 21, 2005   112440-72           11/694,281   Mar. 30, 2007   112440-1010           11/781,078   Jul. 20, 2007   112440-1027           11/679,606   Feb. 27, 2007   112440-1022                      
 
         [0003]     All of the above are incorporated herein by reference.  
     
    
     FIELD OF THE INVENTION  
       [0004]     The present invention relates generally to devices that produce an electro-kinetic flow of air from which particulate matter is substantially removed.  
       BACKGROUND  
       [0005]     The use of an electric motor to rotate a fan blade to create an airflow has long been known in the art. Unfortunately, such fans produce substantial noise, and can present a hazard to children who maybe tempted to poke a finger or a pencil into the moving fan blade. Although such fans can produce substantial airflow (e.g., 1,000 ft 3 /minute or more), substantial electrical power is required to operate the motor, and essentially no conditioning of the flowing air occurs.  
         [0006]     It is known to provide such fans with a HEPA-compliant filter element to remove particulate matter larger than perhaps 0.3 μm. Unfortunately, the resistance to airflow presented by the filter element may require doubling the electric motor size to maintain a desired level of airflow. Further, HEPA-compliant filter elements are expensive, and can represent a substantial portion of the sale price of a HEPA-compliant filter-fan unit. While such filter-fan units can condition the air by removing large particles, particulate matter small enough to pass through the filter element is not removed, including bacteria, for example.  
         [0007]     It is also known in the art to produce an airflow using electro-kinetic techniques, by which electrical power is converted into a flow of air without mechanically moving components. One such system is described in U.S. Pat. No. 4,789,801 to Lee (1988), depicted herein in simplified form as  FIGS. 1A and 1B  and which patent is incorporated herein by reference. System  10  includes an array of first (“emitter”) electrodes or conductive surfaces  20  that are spaced-apart symmetrically from an array of second (“collector”) electrodes or conductive surfaces  30 . The positive terminal of a generator such as, for example, pulse generator  40  that outputs a train of high voltage pulses (e.g., 0 to perhaps +5 KV) is coupled to the first array, and the negative pulse generator terminal is coupled to the second array in this example. It is to be understood that the arrays depicted include multiple electrodes, but that an array can include or be replaced by a single electrode.  
         [0008]     The high voltage pulses ionize the air between the arrays, and create an airflow  50  from the first array toward the second array, without requiring any moving parts. Particulate matter  60  in the air is entrained within the airflow  50  and also moves towards the second electrodes  30 . Much of the particulate matter is electrostatically attracted to the surfaces of the second electrodes, where it remains, thus conditioning the flow of air exiting system  10 . Further, the high voltage field present between the electrode arrays can release ozone into the ambient environment, which can eliminate odors that are entrained in the airflow.  
         [0009]     In the particular embodiment of  FIG. 1A , first electrodes  20  are circular in cross-section, having a diameter of about 0.003″ (0.08 mm), whereas the second electrodes  30  are substantially larger in area and define a “teardrop” shape in cross-section. The ratio of cross-sectional radii of curvature between the bulbous front nose of the second electrode and the first electrodes exceeds 10:1. As shown in  FIG. 1A , the bulbous front surfaces of the second electrodes face the first electrodes, and the somewhat “sharp” trailing edges face the exit direction of the airflow. The “sharp” trailing edges on the second electrodes promote good electrostatic attachment of particulate matter entrained in the airflow.  
         [0010]     In another particular embodiment shown herein as  FIG. 1B , second electrodes  30  are symmetrical and elongated in cross-section. The elongated trailing edges on the second electrodes provide increased area upon which particulate matter entrained in the airflow can attach.  
         [0011]     While the electrostatic techniques disclosed by the &#39;801 patent are advantageous over conventional electric fan-filter units, further increased air transport-conditioning efficiency would be advantageous.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention provides an apparatus as follows.  
         [0013]     One aspect of the present invention is to provide an electro-kinetic air transporter-conditioner that produces an enhanced airflow velocity, enhanced particle collection, and an appropriate amount of ozone production.  
         [0014]     An embodiment includes one or more focus or leading electrodes. Each focus or leading electrode may be located upstream to, or even with, each first electrode. The focus or leading electrodes assists in controlling the flow of ionized particles within the airflow. The focus or leading electrode shapes the electrostatic field generated by each first electrode within the electrode assembly.  
         [0015]     Another embodiment includes one or more trailing electrodes. Each trailing electrode can be located downstream of a second electrode. The trailing electrode can assist in neutralizing the amount of ions exiting this embodiment of the invention, and can further assist in collecting ionized particles. The trailing electrode can alternatively enhance the flow of negative ions from the transporter-conditioner. Additionally, the trailing electrodes can improve the laminar flow properties of the airflow exiting the air transporter-conditioner.  
         [0016]     Another embodiment of the invention includes at least one interstitial electrode located between two second electrodes. The interstitial electrode can also assist in the collection of particulate matter by the second electrodes.  
         [0017]     In yet another embodiment of the invention, one or more of the second electrodes are formed to have an enhanced protective end or trailing surface which assists in the operation and cleaning of the embodiment.  
         [0018]     In still a further embodiment of the invention, one or more first electrode are of enhanced length in order to increase the emissivity of the first electrode.  
         [0019]     Other objects, aspects, features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail, in conjunction with the accompanying drawings and also from the following claim. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIGS. 1A-1B ;  FIG. 1A  is a plan, cross-sectional view, of a first embodiment of an electro-kinetic air transporter-conditioner system according to the prior art;  FIG. 1B  is a plan, cross-sectional view, of a second embodiment of an electro-kinetic air transporter-conditioner system according to the prior art.  
         [0021]      FIGS. 2A-2B ;  FIG. 2A  is a perspective view of a typical embodiment of the housing of an electro-kinetic air transporter-conditioner;  FIG. 2B  is a perspective view of the embodiment shown in  FIG. 2A  illustrating the removable second electrodes.  
         [0022]      FIG. 3  is an electrical block diagram of the present invention.  
         [0023]      FIGS. 4A-4F ;  FIG. 4A  is a perspective view showing an embodiment of an electrode assembly according to the present invention;  FIG. 4B  is a plan view of the embodiment illustrated in  FIG. 4A ;  FIG. 4C  is a perspective view showing another embodiment of an electrode assembly according to the present invention;  FIG. 4D  is a plan view illustrating a modified version of the embodiment of  FIG. 4C ;  FIG. 4E  is a perspective view showing yet another embodiment of an electrode assembly according to the present invention;  FIG. 4F  is a plan view of the embodiment of  FIG. 4E .  
         [0024]      FIGS. 5A-5B ;  FIG. 5A  is a perspective view of still another embodiment of the present invention illustrating the leading or focus electrode added to the embodiment shown in  FIG. 4A ;  FIG. 5B  is a plan view of a modified embodiment of the present invention similar to that shown in  FIG. 5A  illustrating a protective end on each second electrode.  
         [0025]      FIGS. 6A-6D ;  FIG. 6A  is a perspective view of a further embodiment of the present invention, illustrating a leading or focus electrode added to the embodiment shown in  FIG. 4C ;  FIG. 6B  is a perspective view of a modified embodiment of the present invention as shown in  FIG. 6A ;  FIG. 6C  is a perspective view of a modified embodiment of the present invention as shown in  FIG. 6B ;  FIG. 6D  is a modified embodiment of the present invention, illustrating a leading or focus electrode added to the embodiment in  FIG. 4D .  
         [0026]      FIGS. 7A-7C ;  FIG. 7A  is a perspective view of another embodiment of the present invention, illustrating a leading or focus electrode added to the embodiment shown in  FIG. 4E ;  FIG. 7B  is a perspective view of an embodiment modified from that shown in  FIG. 7A ;  FIG. 7C  is a perspective view of an embodiment modified from that shown in  FIG. 7B .  
         [0027]      FIGS. 8A-8C ;  FIG. 8A  is a perspective view of still a further embodiment of the present invention, illustrating another embodiment of the leading or focus electrode;  FIG. 8B  is a perspective view of an embodiment modified from that shown in  FIG. 5A ;  FIG. 8C  is a perspective view of yet another embodiment.  
         [0028]      FIGS. 9A-9C ;  FIG. 9A  is perspective view of a further embodiment of the present invention;  FIG. 9B  is a partial view of an embodiment modified from that shown in  FIG. 1A ;  FIG. 9C  is another embodiment modified from that shown in  FIG. 9A .  
         [0029]      FIGS. 10A-10D ;  FIG. 10A  is a perspective view of another embodiment of the present invention, illustrating a trailing electrode added to the embodiment in  FIG. 7A ;  FIG. 10B  is a plan view of the embodiment shown in  FIG. 10A ;  FIG. 10C  is a plan view of a further embodiment of the present invention;  FIG. 10D  is a plan view of another embodiment of the present invention similar to  FIG. 10C .  
         [0030]      FIGS. 11A-11F ;  FIG. 11A  is a plan view of still another embodiment of the present invention;  FIG. 11B  is a plan view of an embodiment modified from that shown in  FIG. 11A ;  FIG. 11C  is a plan view of a further embodiment of the present invention;  FIG. 11D  is a plan view of an embodiment modified from that shown in  FIG. 11C ;  FIG. 11E  is a plan view of a further embodiment of the present invention;  FIG. 11F  is a plan view of an embodiment modified from that shown in  FIG. 11F .  
         [0031]      FIGS. 12A-12C ;  FIG. 12A  is a perspective view of still another embodiment of the present invention;  FIG. 12B  is a perspective view of a further embodiment of the present invention;  FIG. 12C  is a perspective view of yet another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     Overall Air Transporter-Conditioner System Configuration:  
         [0033]      FIGS. 2A and 2B  depict an electro-kinetic air transporter-conditioner system  100  whose housing  102  includes preferably rear-located intake vents or louvers  104  and preferably front located exhaust vents  106 , and a base pedestal  108 . If desired a single vent can provide and be used as both an air intake and an air exhaust with an air inlet channel and an air exhaust channel communicating with the vent and the electrodes. Preferably the housing is freestanding and/or upstandingly vertical and/or elongated. Internal to the transporter housing is an ion generating unit  160 , preferably powered by an AC:DC power supply that is energizable or excitable using switch S 1 . S 1 , which along with the other below described user operated switches are conveniently located at the top  103  of the unit  100 . Ion generating unit  160  is self-contained in that other ambient air, nothing is required from beyond the transporter housing, save external operating potential, for operation of the present invention.  
         [0034]     The upper surface of housing  102  includes a user-liftable handle member  112  to which is affixed a second array  240  of collector electrodes  242  within an electrode assembly  220 . Electrode assembly  220  also comprises a first array of emitter electrodes  230 , or a single first electrode shown here as a single wire or wire-shaped electrode  232 . (The terms “wire” and “wire-shaped” shall be used interchangeably herein to mean an electrode either made from a wire or, if thicker or stiffer than a wire, having the appearance of a wire.) In the embodiment shown, lifting member  112  lifts second array electrodes  240  upward, causing the second electrode to telescope out of the top of the housing and, if desired, out of unit  100  for cleaning, while the first electrode array  230  remains within unit  100 . As is evident from the figure, the second array of electrode can be lifted vertically out from the top  103  of unit  100  along the longitudinal axis or direction of the elongated housing  102 . This arrangement with the second electrodes removable from the top  103  of the unit  100 , makes it easy for the user to pull the second electrodes out for cleaning. In  FIG. 2B , the bottom ends of second electrodes  242  are connected to a member  113 , to which is attached a mechanism  500 , which includes a flexible member and a slot for capturing and cleaning the first electrode  232 , whenever handle member  112  is moved upward or downward by a user.  
         [0035]     The first and second arrays of electrodes are coupled to the output terminals of ion generating unit  160 , as best seen in  FIG. 3 .  
         [0036]     The general shape of the embodiment of the invention shown in  FIGS. 2A and 2B  is that of a figure eight in cross-section, although other shapes are within the spirit and scope of the invention. The top-to-bottom height of the preferred embodiment is in one preferred embodiment, 1 m, with a left-to-right width of preferably 15 cm, and a front-to-back depth of perhaps 10 cm, although other dimensions and shapes can of course be used. A louvered construction provides ample inlet and outlet venting in an economical housing configuration. There need be no real distinction between vents  104  and  106 , except their location relative to the second electrodes. These vents serve to ensure that an adequate flow of ambient air can be drawn into or made available to the unit  100 , and that an adequate flow of ionized air that includes appropriate amounts of O 3  flows out from unit  100 .  
         [0037]     As will be described, when unit  100  is energized with S 1 , high voltage or high potential output by ion generator  160  produces ions at the first electrode, which ions are attracted to the second electrodes. The movement of the ions in an “IN” to “OUT” direction carries with the ions air molecules, thus electro-kinetically producing an outflow of ionized air. The “IN” notation in  FIGS. 2A and 2B  denote the intake of ambient air with particulate matter  60 . The “OUT” notation in the figures denotes the outflow of cleaned air substantially devoid of the particulate matter, which particulates matter adheres electrostatically to the surface of the second electrodes. In the process of generating the ionized airflow appropriate amounts of ozone (O 3 ) are beneficially produced. It may be desired to provide the inner surface of housing  102  with an electrostatic shield to reduces detectable electromagnetic radiation. For example, a metal shield could be disposed within the housing, or portions of the interior of the housing can be coated with a metallic paint to reduce such radiation.  
         [0038]     The housing preferably has a substantially oval-shaped or -elliptically shaped cross-section with dimpled side grooves. Thus, as indicated above, the cross-section looks somewhat like a figure eight. It is within the scope of the present invention for the housing to have a different shaped cross-section such as, but not limited to, a rectangular shape, an egg shape, a tear-drop shape, or circular shape. The housing preferably has a tall, thin configuration. As will become apparent later, the housing is preferably functionally shaped to contain the electrode assembly.  
         [0039]     As mentioned above, the housing has an inlet and an outlet. Both the inlet and the outlet are covered by fins or louvers. Each fin is a thin ridge spaced-apart from the next fin, so that each fin creates minimal resistance as air flows through the housing. The fins are horizontal and are directed across the elongated vertical upstanding housing of the unit. Thus, the fins are substantially perpendicular in this preferred embodiment to the electrodes. The inlet and outlet fins are aligned to give the unit a “see through” appearance. Thus, a user can “see through” the unit from the inlet to the outlet. The user will see no moving parts within the housing, but just a quiet unit that cleans the air passing therethrough. Alternatively the fins can be parallel with the electrodes in another preferred embodiment. Other orientations of fins and electrodes are possible in other embodiments.  
         [0040]     As best seen in  FIG. 3 , ion generating unit  160  includes a high voltage generator unit  170  and circuitry  180  for converting raw alternating voltage (e.g., 117 VAC) into direct current (“DC”) voltage. Circuitry  180  preferably includes circuitry controlling the shape and/or duty cycle of the generator unit output voltage (which control is altered with user switch S 2 ). Circuitry  180  preferably also includes a pulse mode component, coupled to switch S 3 , to temporarily provide a burst of increased output ozone. Circuitry  180  can also include a timer circuit and a visual indicator such as a light emitting diode (“LED”). The LED or other indicator (including, if desired, an audible indicator) signals when ion generation quits occurring. The timer can automatically halt generation of ions and/or ozone after some predetermined time, e.g., 30 minutes.  
         [0041]     The high voltage generator unit  170  preferably comprises a low voltage oscillator circuit  190  of perhaps 20 KHz frequency, that outputs low voltage pulses to an electronic switch  200 , e.g., a thyristor or the like. Switch  200  switchably couples the low voltage pulses to the input winding of a step-up transformer T 1 . The secondary winding of T 1  is coupled to a high voltage multiplier circuit  210  that outputs high voltage pulses. Preferably the circuitry and components comprising high voltage pulse generator  170  and circuit  180  are fabricated on a printed circuit board that is mounted within housing  102 . If desired, external audio input (e.g., from a stereo tuner) could be suitably coupled to oscillator  190  to acoustically modulate the kinetic airflow produced by unit  160 . The result would be an electrostatic loudspeaker, whose output airflow is audible to the human ear in accordance with the audio input signal. Further, the output air stream would still include ions and ozone.  
         [0042]     Output pulses from high voltage generator  170  preferably are at least 10 KV peak-to-peak with an effective DC offset of, for example, half the peak-to-peak voltage, and have a frequency of, for example, 20 KHz. Frequency of oscillation can include other values, but frequency of at least about 20 KHz is preferred as being inaudible to humans. If pets will be in the same room as the unit  100 , it may be desired to utilize and even higher operating frequency, to prevent pet discomfort and/or howling by the pet. The pulse train output preferably has a duty cycle of for example 10%, which will promote battery lifetime if live current is not used. Of course, different peak-peak amplitudes, DC offsets, pulse train waveshapes, duty cycle, and/or repetition frequencies can be used instead. Indeed, a 100% pulse train (e.g., an essentially DC high voltage) may be used, albeit with shorter battery lifetime. Thus, generator unit  170  for this embodiment can be referred to as a high voltage pulse generator. Unit  170  functions as a DC:DC high voltage generator, and could be implemented using other circuitry and/or techniques to output high voltage pulses that are input to electrode assembly  220 .  
         [0043]     As noted, outflow (OUT) preferably includes appropriate amounts of ozone that can remove odors and preferably destroy or at least substantially alter bacteria, germs, and other living (or quasi-living) matter subjected to the outflow. Thus, when switch S 1  is closed and the generator  170  has sufficient operating potential, pulses from high voltage pulse generator unit  170  create an outflow (OUT) of ionized air and ozone. When S 1  is closed, LED will visually signal when ionization is occurring.  
         [0044]     Preferably operating parameters of unit  100  are set during manufacture and are generally not user-adjustable. For example, with respect to operating parameters, increasing the peak-to-peak output voltage and/or duty cycle in the high voltage pulses generated by unit  170  can increase the airflow rate, ion content, and ozone content. These parameters can be set by the user by adjusting switch S 2  as disclosed below. In the preferred embodiment, output flowrate is about 200 feet/minute, ion content is about 2,000,000/cc and ozone content is about 40 ppb (over ambient) to perhaps 2,000 ppb (over ambient). Decreasing the ratio of the radius of the nose of the second electrodes to the radius of the first electrode or decreasing the ratio of the cross-sectioned area of the second electrode to the first electrode below about 20:1 will decrease flow rate, as will decreasing the peak-to-peak voltage and/or duty cycle of the high voltage pulses coupled between the first and second electrode arrays.  
         [0045]     In practice, unit  100  is placed in a room and connected to an appropriate source of operating potential, typically 117 VAC. With S 1  energizing ionization unit  160 , systems  100  emits ionized air and preferably some ozone via outlet vents  106 . The airflow, coupled with the ions and ozone freshens the air in the room, and the ozone can beneficially destroy or at least diminish the undesired effects of certain odors, bacteria, germs, and the like. The airflow is indeed electro-kinetically produced, in that there are no intentionally moving parts within unit  100 . (Some mechanical vibration may occur within the electrodes.).  
         [0046]     Having described various aspects of this embodiment of the invention in general, preferred embodiments of electrode assembly  220  are now described. In the various embodiments, electrode assembly  220  comprises a first array  230  of at least one electrode or conductive surface  232 , and further comprises a second array  240  of preferably at least one electrode or conductive surface  242 . Understandably material(s) for electrodes  232  and  242  should conduct electricity, be resistant to corrosive effects from the application of high voltage, yet be strong enough to be cleaned.  
         [0047]     In the various electrode assemblies to be described herein, electrode(s)  232  in the first electrode array  230  are preferably fabricated from tungsten. Tungsten is sufficiently robust in order to withstand cleaning, has a high melting point to retard breakdown due to ionization, and has a rough exterior surface that seems to promote efficient ionization. On the other hand, electrode(s)  242  preferably have a highly polished exterior surface to minimize unwanted point-to-point radiation. As such, electrode(s)  242  preferably are fabricated from stainless steel and/or brass, among other materials. The polished surface of electrode(s)  232  also promotes ease of electrode cleaning.  
         [0048]     In contrast to the prior art electrodes disclosed by the &#39;801 patent, electrodes  232  and  242 , are light weight, easy to fabricate, and lend themselves to mass production. Further, electrodes  232  and  242  described herein promote more efficient generation of ionized air, and appropriate amounts of ozone, (indicated in several of the figures as O 3 ).  
         [0049]     Electrode Assembly with First and Second Electrodes:  
         [0050]    
       FIGS. 4A-4F 
     
         [0051]      FIGS. 4A-4F  illustrate various configurations of the electrode assembly  220 . The output from high voltage pulse generator unit  170  is coupled to an electrode assembly  220  that comprises a first electrode array  230  and a second electrode array  240 . Again, instead of arrays, single electrodes or single conductive surfaces can be substituted for one or both array  230  and array  240 .  
         [0052]     The positive output terminal of unit  170  is coupled to first electrode array  230 , and the negative output terminal is coupled to second electrode array  240 . It is believed that with this arrangement the net polarity of the emitted ions is positive, e.g., more positive ions than negative ions are emitted. This coupling polarity has been found to work well, including minimizing unwanted audible electrode vibration or hum. However, while generation of positive ions is conducive to a relatively silent airflow, from a health standpoint, it is desired that the output airflow be richer in negative ions, not positive ions. It is noted that in some embodiments, one port (preferably the negative port) of the high voltage pulse generator can in fact be the ambient air. Thus, electrodes in the second array need not be connected to the high voltage pulse generator using a wire. Nonetheless, there will be an “effective connection” between the second array electrodes and one output port of the high voltage pulse generator, in this instance, via ambient air. Alternatively the negative output terminal of unit  170  can be connected to the first electrode array  230  and the positive output terminal can be connected to the second electrode array  240 .  
         [0053]     With this arrangement an electrostatic flow of air is created, going from the first electrode array towards the second electrode array. (This flow is denoted “OUT” in the figures.) Accordingly electrode assembly  220  is mounted within transporter system  100  such that second electrode array  240  is closer to the OUT vents and first electrode array  230  is closer to the IN vents.  
         [0054]     When voltage or pulses from high voltage pulse generator  170  are coupled across first and second electrode arrays  230  and  240 , a plasma-like field is created surrounding electrodes  232  in first array  230 . This electric field ionizes the ambient air between the first and second electrode arrays and establishes an “OUT” airflow that moves towards the second array. It is understood that the IN flow enters via vent(s)  104 , and that the OUT flow exits via vent(s)  106 .  
         [0055]     Ozone and ions are generated simultaneously by the first array electrodes  232 , essentially as a function of the potential from generator  170  coupled to the first array of electrodes or conductive surfaces. Ozone generation can be increased or decreased by increasing or decreasing the potential at the first array. Coupling an opposite polarity potential to the second array electrodes  242  essentially accelerates the motion of ions generated at the first array, producing the airflow denoted as “OUT” in the figures. As the ions and ionized particulates move toward the second array, the ions and ionized particles push or move air molecules toward the second array. The relative velocity of this motion may be increased, by way of example, by decreasing the potential at the second array relative to the potential at the first array.  
         [0056]     For example, if +10 KV were applied to the first array electrode(s), and no potential were applied to the second array electrode(s), a cloud of ions (whose net charge is positive) would form adjacent the first electrode array. Further, the relatively high 10 KV potential would generate substantial ozone. By coupling a relatively negative potential to the second array electrode(s), the velocity of the air mass moved by the net emitted ions increases.  
         [0057]     On the other hand, if it were desired to maintain the same effective outflow (OUT) velocity, but to generate less ozone, the exemplary 10 KV potential could be divided between the electrode arrays. For example, generator  170  could provide +4 KV (or some other fraction) to the first array electrodes and −6 KV (or some other fraction) to the second array electrodes. In this example, it is understood that the +4 KV and the −6 KV are measured relative to ground. Understandably it is desired that the unit  100  operates to output appropriate amounts of ozone. Accordingly, the high voltage is preferably fractionalized with about +4 KV applied to the first array electrodes and about −6 KV applied to the second array electrodes.  
         [0058]     In the embodiments of  FIGS. 4A and 4B , electrode assembly  220  comprises a first array  230  of wire-shaped electrodes  232 , and a second array  240  of generally “U”-shaped electrodes  242 . In preferred embodiments, the number N 1  of electrodes comprising the first array can preferably differ by one relative to the number N 2  of electrodes comprising the second array  240 . In many of the embodiments shown, N 2 &gt;N 1 . However, if desired, additional first electrodes  232  could be added at the outer ends of array  230  such that N 1 &gt;N 2 , e.g., five first electrodes  232  compared to four second electrodes  242 .  
         [0059]     As previously indicated first or emitter electrodes  232  are preferably lengths of tungsten wire, whereas electrodes  242  are formed from sheet metal, preferably stainless steel, although brass or other sheet metal could be used. The sheet metal is readily configured to define side regions  244  and bulbous nose region  246 , forming the hollow, elongated “U”-shaped electrodes  242 . While  FIG. 4A  depicts four electrodes  242  in second array  240  and three electrodes  232  in first array  230 , as noted previously, other numbers of electrodes in each array could be used, preferably retaining a symmetrically staggered configuration as shown. It is seen in  FIG. 4A  that while particulate matter  60  is present in the incoming (IN) air, the outflow (OUT) air is substantially devoid of particulate matter, which adheres to the preferably large surface area provided by the side regions  244  of the second array electrodes  242 .  
         [0060]      FIG. 4B  illustrates that the spaced-apart configuration between the first and second arrays  230 , 240  is staggered. Preferably, each first array electrode  232  is substantially equidistant from two second array electrodes  242 . This symmetrical staggering has been found to be an efficient electrode placement. Preferably, in this embodiment, the staggering geometry is symmetrical in that adjacent electrodes  232  or adjacent electrodes  242  are spaced-apart a constant distance, Y 1  and Y 2  respectively. However, a non-symmetrical configuration could also be used. Also, it is understood that the number of electrodes  232  and  242  may differ from what is shown.  
         [0061]     In the embodiment of  FIG. 4A , typically dimensions are as follows: diameter of electrodes  232 , R 1 , is about 0.08 mm, distances Y 1  and Y 2  are each about 16 mm, distance X 1  is about 16 mm, distance L is about 20 mm, and electrode heights Z 1  and Z 2  are each about 1 m. The width W of electrodes  242  is preferably about 4 mm, and the thickness of the material from which electrodes  242  are formed is about 0.5 mm. Of course other dimensions and shapes could be used. For example, preferred dimensions for distance X 1  may vary between 12-30 mm, and the distance Y 2  may vary between 15-30 mm. It is preferred that electrodes  232  have a small diameter. A wire having a small diameter, such as R 1 , generates a high voltage field and has a high emissivity. Both characteristics are beneficial for generating ions. At the same time, it is desired that electrodes  232  (as well as electrodes  242 ) be sufficiently robust to withstand occasional cleaning.  
         [0062]     Electrodes  232  in first array  230  are coupled by a conductor  234  to a first (preferably positive) output port of high voltage pulse generator  170 . Electrodes  242  in second array  240  are coupled by a conductor  249  to a second (preferably negative) output port of high voltage generator  170 . The electrodes maybe electrically connected to the conductors  234  or  249  at various locations. By way of example only,  FIG. 4B  depicts conductor  249  making connection with some electrodes  242  internal to bulbous end  246 , while other electrodes  242  make electrical connection to conductor  249  elsewhere on the electrode  242 . Electrical connection to the various electrodes  242  could also be made on the electrode external surface, provided no substantial impairment of the outflow airstream results; however it has been found to be preferable that the connection is made internally.  
         [0063]     In this and the other embodiments to be described herein, ionization appears to occur at the electrodes  232  in the first electrode array  230 , with ozone production occurring as a function of high voltage arcing. For example, increasing the peak-to-peak voltage amplitude and/or duty cycle of the pulses from the high voltage pulse generator  170  can increase ozone content in the output flow of ionized air. If desired, user-control S 2  can be used to somewhat vary ozone content by varying amplitude and/or duty cycle. Specific circuitry for achieving such control is known in the art and need not be described in detail herein.  
         [0064]     Note the inclusion in  FIGS. 4A and 4B  of at least one output controlling electrodes  243 , preferably electrically coupled to the same potential as the second array electrodes  242 . Electrode  243  preferably defines a pointed shape in side profile, e.g., a triangle. The sharp point on electrodes  243  causes generation of substantial negative ions (since the electrode is coupled to relatively negative high potential). These negative ions neutralize excess positive ions otherwise present in the output airflow, such that the OUT flow has a net negative charge. Electrodes  243  is preferably stainless steel, copper, or other conductor material, and is perhaps 20 mm high and about 12 mm wide at the base. The inclusion of one electrode  243  has been found sufficient to provide a sufficient number of output negative ions, but more such electrodes may be included.  
         [0065]     In the embodiments of  FIGS. 4A, 4B  and  4 C, each “U”-shaped electrode  242  has two trailing surface or sides  244  that promote efficient kinetic transport of the outflow of ionized air and ozone. For the embodiment of  FIG. 4C , there is the inclusion on at least one portion of a trailing edge of a pointed electrode region  243 ′. Electrode region  243 ′ helps promote output of negative ions, in the same fashion that was previously described with respect to electrodes  243 , as shown in  FIGS. 4A and 4B .  
         [0066]     In  FIG. 4C  and the figures to follow, the particulate matter is omitted for ease of illustration. However, from what was shown in  FIGS. 4A-4B , particulate matter will be present in the incoming air, and will be substantially absent from the outgoing air. As has been described, particulate matter  60  typically will be electrostatically precipitated upon the surface area of electrodes  242 .  
         [0067]     As discussed above and as depicted by  FIG. 4C , it is relatively unimportant where on an electrode array electrical connection is made. Thus, first array electrodes  232  are shown electrically connected together at their bottom regions by conductor  234 , whereas second array electrodes  242  are shown electrically connected together in their middle regions by the conductor  249 . Both arrays maybe connected together in more than one region, e.g., at the top and at the bottom. It is preferred that the wire or strips or other inter-connecting mechanisms be at the top, bottom, or periphery of the second array electrodes  242 , so as to minimize obstructing stream air movement through the housing  210 .  
         [0068]     It is noted that the embodiments of  FIGS. 4C and 4D  depict somewhat truncated versions of the second electrodes  242 . Whereas dimension L in the embodiment of  FIGS. 4A and 4B  was about 20 mm, in  FIGS. 4C and 4D , L has been shortened to about 8 mm. Other dimensions in  FIG. 4C  preferably are similar to those stated for  FIGS. 4A and 4B . It will be appreciated that the configuration of second electrode array  240  in  FIG. 4C  can be more robust than the configuration of  FIGS. 4A and 4B , by virtue of the shorter trailing edge geometry. As noted earlier, a symmetrical staggered geometry for the first and second electrode arrays is preferred for the configuration of  FIG. 4C .  
         [0069]     In the embodiment of  FIG. 4D , the outermost second electrodes, denoted  242 - 1  and  242 - 4 , have substantially no outermost trailing edges. Dimension L in  FIG. 4D  is preferably about 3 mm, and other dimensions maybe as stated for the configuration of  FIGS. 4A and 4B . Again, the ratio of the radius or surface areas between the first electrode  232  and the second electrodes  242  for the embodiment of  FIG. 4D  preferably exceeds about 20:1.  
         [0070]      FIGS. 4E and 4F  depict another embodiment of electrode assembly  220 , in which the first electrode array  230  comprises a single wire electrode  232 , and the second electrode array  240  comprises a single pair of curved “L”-shaped electrodes  242 , in cross-section. Typical dimensions, where different than what has been stated for earlier-described embodiments, are X 1 ≈12 mm, Y 2 ≈5 mm, and L 1 ≈3 mm. The effective surface area or radius ratio is again greater than about 20:1. The fewer electrodes comprising assembly  220  in  FIGS. 4E and 4F  promote economy of construction, and ease of cleaning, although more than one electrode  232 , and more than two electrodes  242  could of course be employed. This particular embodiment incorporates the staggered symmetry described earlier, in which electrode  232  is equidistant from two electrodes  242 . Other geometric arrangements, which may not be equidistant, are within the spirit and scope of the invention.  
         [0071]     Electrode Assembly with an Upstream Focus Electrode:  
         [0072]    
       FIGS. 5A-5B 
     
         [0073]     The embodiments illustrated in  FIGS. 5A-5B  are somewhat similar to the previously described embodiments in  FIGS. 4A-4B . The electrode assembly  220  includes a first array of electrodes  230  and a second array of electrodes  240 . Again, for this and the other embodiments, the term “array of electrodes” may refer to a single electrode or a plurality of electrodes. Preferably, the number of electrodes  232  in the first array of electrodes  230  will differ by one relative to the number of electrodes  242  in the second array of electrodes  240 . The distances L, X 1 , Y 1 , Y 2 , Z 1  and Z 2  for this embodiment are similar to those previously described in  FIG. 4A .  
         [0074]     As shown in  FIG. 5A , the electrode assembly  220  preferably adds a third, or leading, or focus, or directional electrode  224   a ,  224   b ,  224   c  (generally referred to as “electrode  224 ”) upstream of each first electrode  232 - 1 ,  232 - 2 ,  232 - 3 . The focus electrode  224  produces an enhanced airflow velocity exiting the devices  100  or  200 . In general, the third focus electrode  224  directs the airflow, and ions generated by the first electrode  232 , towards the second electrodes  242 . Each third focus electrode  224  is a distance X 2  upstream from at least one of the first electrodes  232 . The distance X 2  is preferably 5-6 mm, or four to five diameters of the focus electrode  224 . However, the third focus electrode  224  can be further from or closer to the first electrode  232 .  
         [0075]     The third focus electrode  224  illustrated in  FIG. 5A  is a rod-shaped electrode. The third focus electrode  224  can also comprise other shapes that preferably do not contain any sharp edges. The third focus electrode  224  is preferably manufactured from material that will not erode or oxidize, such as stainless steel. The diameter of the third focus electrode  224 , in a preferred embodiment, is at least fifteen times greater than the diameter of the first electrode  232 . The diameter of the third focus electrode  224  can be larger or smaller. The diameter of the third focus electrode  224  is preferably large enough so that third focus electrode  224  does not function as an ion emitting surface when electrically connected with the first electrode  232 . The maximum diameter of the third focus electrode  224  is somewhat constrained. As the diameter increases, the third focus electrode  224  will begin to noticeably impair the airflow rate of the units  100  or  200 . Therefore, the diameter of the third electrode  224  is balanced between the need to form a non-ion emitting surface and airflow properties of the unit  100  or  200 .  
         [0076]     In a preferred embodiment, each third focus electrodes  224   a ,  224   b ,  224   c  are electrically connected with the first array  230  and the high voltage generator  170  by the conductor  234 . As shown in  FIG. 5A , the third focus electrodes  224  are electrically connected to the same positive outlet of the high voltage generator  170  as the first array  230 . Accordingly, the first electrode  232  and the third focus electrode  224  generate a positive electrical field. Since the electrical fields generated by the third focus electrode  224  and the first electrode  232  are both positive, the positive field generated by the third focus electrode  224  can push, or repel, or direct, the positive field generated by the first electrode  232  towards the second array  240 . For example, the positive field generated by the third focus electrode  224   a  will push, or repel, or direct, the positive field generated by the first electrode  232 - 1  towards the second array  240 . In general, the third focus electrode  224  shapes the electrical field generated by each electrode  232  in the first array  230 . This shaping effect is believe to decrease the amount of ozone generated by the electrode assembly  220  and increases the airflow of the units  100  and  200 .  
         [0077]     The particles within the airflow are positively charged by the ions generated by the first electrode  232 . As previously mentioned, the positively charged particles are collected by the negatively charged second electrodes  242 . The third focus electrode  224  also directs the airflow towards the second electrodes  242  by guiding the charged particles towards the trailing sides  244  of each second electrode  242 . It is believed that the airflow will travel around the third focus electrode  224 , partially focusing the airflow towards the trailing sides  244 , improving the collection rate of the electrode assembly  220 .  
         [0078]     The third focus electrode  224  maybe located at various positions upstream of each first electrode  232 . By way of example only, a third focus electrode  224   b  is located directly upstream of the first electrode  232 - 2  so that the center of the third focus electrode  224   b  is in-line and symmetrically aligned with the first electrode  232 - 2 , as shown by extension line B. Extension line B is located midway between the second electrode  242 - 2  and the second electrode  242 - 3 .  
         [0079]     Alternatively, a third focus electrode  224  can also be located at an angle relative to the first electrode  232 . For example, a third focus electrode  224   a  can be located upstream of the first electrode  232 - 1  along a line extending from the middle of the nose  246  of the second electrode  242 - 2  through the center of the first electrode  232 - 1 , as shown by extension line A. The third focus electrode  224   a  is in-line and symmetrically aligned with the first electrode  232 - 1  along extension line A. Similarly, the third electrode  224   c  is located upstream to the first electrode  232 - 3  along a line extending from the middle of the nose  246  of the second electrode  242 - 3  through the first electrode  232 - 3 , as shown by extension line C. The third focus electrode  224   c  is in-line and symmetrically aligned with the first electrode  232 - 3  along extension line C. It is within the scope of the present invention for the electrode assembly  220  to include third focus electrodes  224  that are both directly upstream and at an angle to the first electrodes  232 , as depicted in  FIG. 5A . Thus the focus electrodes fan out relating to the first electrodes.  
         [0080]      FIG. 5B  illustrates that an electrode assembly  220  may contain multiple third focus electrodes  224  upstream of each first electrode  232 . By way of example only, the third focus electrode  224   a   2  is in-line and symmetrically aligned with the third focus electrode  224   a   1 , as shown by extension line A. In a preferred embodiment, only the third focus electrodes  224   a   1 ,  224   b   1 ,  224   c   1  are electrically connected to the high voltage generator  170  by conductor  234 . Accordingly, not all of the third electrodes  224  are at the same operating potential. In the embodiment shown in  FIG. 5B , the third focus electrodes  224   a   1 ,  224   b   1 ,  224   c   1  are at the same electrical potential as the first electrodes  232 , while the third focus electrodes  224   a   2 ,  224   b   2 ,  224   c   2  are floating. Alternatively, the third focus electrodes  224   a   2 ,  224   b   2  and  224   c   2  maybe electrically connected to the high voltage generator  170  by the conductor  234 .  
         [0081]      FIG. 5B  illustrates that each second electrode  242  may also have a protective end  241 . In the previous embodiments, each “U”-shaped second electrode  242  has an open end. Typically, the end of each trailing side or side wall  244  contains sharp edges. The gap between the trailing sides or side walls  244 , and the sharp edges at the end of the trailing sides or side walls  244 , generate unwanted eddy currents. The eddy currents create a “backdraft,” or airflow traveling from the outlet towards the inlet, which slow down the airflow rate of the units  100  or  200 .  
         [0082]     In a preferred embodiment, the protective end  241  is created by shaping, or rolling, the trailing sides or side walls  244  inward and pressing them together, forming a rounded trailing end with no gap between the trailing sides or side walls of each second electrode  242 . Accordingly the side walls have outer surfaces, and the outer surface of end of the side walls are bent back adjacent to the trailing ends of the side walls so that the outer surface of the side walls are adjacent to, or face, or touch each other. Accordingly a smooth trailing edge is integrally formed on the second electrode. If desired, it is within the scope of the invention to spot weld the rounded ends together along the length of the second electrode  242 . It is also within the scope of the present invention to form the protective end  241  by other methods such as, but not limited to, placing a strap of plastic across each end of the trailing sides  244  for the full length of the second electrode  242 . The rounded or capped end is an improvement over the previous electrodes  242  without a protective end  241 . Eliminating the gap between the trailing sides  244  also reduces or eliminates the eddy currents typically generated by the second electrode  242 . The rounded protective end also provides a smooth surface for purpose of cleaning the second electrode. Accordingly in this embodiment the collector electrode is a one-piece, integrally formed, electrode with a protection end.  
         [0083]    
       FIGS. 6A-6D 
     
         [0084]      FIG. 6A  illustrates an electrode assembly  220  including a first array of electrodes  230  having three wire-shaped first electrodes  232 - 1 ,  232 - 2 ,  232 - 3  (generally referred to as “electrode  232 ”) and a second array of electrodes  240  having four “U”-shaped second electrodes  242 - 1 ,  242 - 2 ,  242 - 3 ,  242 - 4  (generally referred to as “electrode  242 ”). Each first electrode  232  is electrically connected to the high voltage generator  170  at the bottom region, whereas each second electrode  242  is electrically connected to the high-voltage generator  170  in the middle to illustrate that the first and second electrodes  232 ,  242  can be electrically connected in a variety of locations.  
         [0085]     The second electrode  242  in  FIG. 6A  is a similar version of the second electrode  242  shown in  FIG. 4C . The distance L has been shortened to about 8 mm, while the other dimensions X 1 , Y 1 , Y 2 , Z 1 , Z 2  are similar to those shown in  FIG. 4A .  
         [0086]     A third leading or focus electrode  224  is located upstream of each first electrode  232 . The innermost third focus electrode  224   b  is located directly upstream of the first electrode  232 - 2 , as shown by extension line B. Extension line B is located midway between the second electrodes  242 - 2 ,  242 - 3 . The third focus electrodes  224   a ,  224   c  are at an angle with respect to the first electrodes  232 - 1 ,  232 - 3 . For example, the third focus electrode  224   a  is upstream to the first electrode  232 - 1  along a line extending from the middle of the nose  246  of the second electrode  242 - 2  extending through the center of the first electrode  232 - 1 , as shown by extension line A. The third electrode  224   c  is located upstream of the first electrode  232 - 3  along a line extending from the center of the nose  246  of the second electrode  242 - 3  through the center of the first electrode  232 - 3 , as shown by extension line C. Accordingly and preferably the focus electrodes fan out relative to the first electrodes as an aid for directing the flow of ions and charged particles.  FIG. 6B  illustrates that the third focus electrodes  224  and the first electrode  232  may be electrically connected to the high voltage generator  170  by conductor  234 .  
         [0087]      FIG. 6C  illustrates that a pair of third focus electrodes  224  maybe located upstream of each first electrode  232 . Preferably, the multiple third focus electrodes  224  are in-line and symmetrically aligned with each other. For example, the third focus electrode  224   a   2  is in-line and symmetrically aligned with the third focus electrode  224   a   1 , along extension line A. As previously mentioned, preferably only third focus electrodes  224   a   1 ,  224   b   1 ,  224   c   1  are electrically connected with the first electrodes  232  by conductor  234 . It is also within the scope of the present invention to have none or all of the third focus electrodes  224  electrically connected to the high voltage generator  170 .  
         [0088]      FIG. 6D  illustrates third focus electrodes  224  added to the electrode assembly  220  shown in  FIG. 4D . Preferably, a third focus electrode  224  is located upstream of each first electrode  232 . For example, the third focus electrode  224   b  is in-line and symmetrically aligned with the first electrode  232 - 2 , as shown by extension line B. Extension line B is located midway between the second electrodes  242 - 2 ,  242 - 3 . The third focus electrode  224   a  is in-line and symmetrically aligned with the first electrode  232 - 1 , as shown by extension line A. Similarly, the third electrode  224   c  is in-line and symmetrically aligned with the first electrode  232 - 3 , as shown by extension line C. Extension lines A-C extend from the middle of the nose  246  of the “U”-shaped second electrodes  242 - 2 ,  242 - 3  through the first electrodes  232 - 1 ,  232 - 3 , respectively. In a preferred embodiment, the third electrodes  224   a ,  224   b ,  224   c  with the high voltage generator  170  by the conductor  234 . This embodiment can also include a pair of third focus electrodes  224  upstream of each first electrode  232  as is depicted in  FIG. 6C .  
         [0089]    
       FIGS. 7A-7C 
     
         [0090]      FIGS. 7A-7C  illustrate that the electrode assembly  220  shown in  FIG. 4E  can include a third focus electrode upstream of the first array of electrodes  230  comprising a single wire electrode  232 . Preferably, the center of the third focus electrode  224  is in-line and symmetrically aligned with the center of the first electrode  232 , as shown by extension line B. Extension line B is located midway between the second electrodes  242 . The distances X 1 , X 2 , Y 1 , Y 2 , Z 1  and Z 2  are similar to the embodiments previously described. The first electrode  232  and the second electrode  242  may be electrically connected to the high-voltage generator  170  by conductor  234 ,  249  respectively. It is within the scope of the present invention to connect the first and second electrodes to opposite ends of the high voltage generator  170  (e.g., the first electrode  232  maybe negatively charged and the second electrode  242  may be positively charged). In a preferred embodiment the third focus electrode  224  is also electrically connected to the high voltage generator  170 .  
         [0091]      FIG. 7B  illustrates that a pair of third focus electrodes  224   a ,  224   b  maybe located upstream of the first electrode  232 . The third focus electrodes  224   a ,  224   b  are in-line and symmetrically aligned with the first electrode  232 , as shown by extension line B. Extension line B is located midway between the second electrodes  242 . Preferably, the third focus electrode  224   b  is upstream of third focus electrode  224   a  a distance equal to the diameter of a third focus electrode  224 . In a preferred embodiment, only the third focus electrode  224   a  is electrically connected to the high voltage generator  170 . It is within the scope of the present invention to electrically connect both third focus electrodes  224   a ,  224   b  to the high voltage generator  170 .  
         [0092]      FIG. 7C  illustrates that each third focus electrode  224  can be located at an angle with respect to the first electrode  232 . Similar to the previous embodiments, the third focus electrode  224   a   1  and  224   b   1  is located a distance X 2  upstream from the first electrode  232 . By way of example only, the third focus electrodes  224   a   1 ,  224   a   2  are located along a line extending from the middle of the second electrode  242 - 2  through the center of the first electrode  232 , as shown by extension line A. Similarly, the third focus electrodes  224   b   1 ,  224   b   2  are along a line extending from the middle of the second electrode  242 - 1  through the middle of the first electrode  232 , as shown by extension line B. The third focus electrode  224   a   2  is in-line and symmetrically aligned with the third focus electrode  224   a   1  along extension line A. Similarly, the third focus electrode  224   b   2  is in line and symmetrically aligned with the third focus electrode  224   b   1  along extension line B. The third focus electrodes  224  are fanned out and form a “V” pattern upstream of first electrode  232 . In a preferred embodiment, only the third focus electrodes  224   a   1  and  224   b   1  are electrically connected to the high-voltage generator  170  by conductor  234 . It is within the scope of the invention to electrically connect the third focus electrodes  224   a  and  224   b   2  to the high voltage generator  170 .  
         [0093]    
       FIGS. 8A-8B 
     
         [0094]     The previously described embodiments of the electrode assembly  220  disclose a rod-shaped third focus electrode  224  upstream of each first electrode  232 .  FIG. 8A  illustrates an alternative configuration for the third focus electrode  224 . By way of example only, the electrode assembly  220  may include a “U”-shaped or possibly “C”-shaped third focus electrode  224  upstream of each first electrode  232 . Further the third focus electrode  224  can have other curved configurations such as, but not limited to, circular-shaped, elliptical-shaped, and parabolically-shaped other concave shapes facing the first electrode  232 . In a preferred embodiment, the third focus electrode  224  has holes  225  extending through, forming a perforated surface to minimize the resistance of the third focus electrode  224  on the airflow rate.  
         [0095]     In a preferred embodiment, the third focus electrode  224  is electrically connected to the high voltage generator  170  by conductor  234 . The third focus electrode  224  in  FIG. 8A  is preferably not an ion emitting surface. Similar to previous embodiments, the third focus electrode  224  generates a positive electric field and pushes or repels the electric field generated by the first electrode  232  towards the second array  240 .  
         [0096]      FIG. 8B  illustrates that a perforated “U”-shaped or “C”-shaped third focus electrode  224  can be incorporated into the electrode assembly  220  shown in  FIG. 4A . Even though only two configurations of the electrode assembly  220  are shown with the perforated “U”-shaped third focus electrode  224 , all the embodiments described in  FIGS. 5A-12C  may incorporate the perforated “U”-shaped third focus electrode  224 . It is also within the scope of the invention to have multiple perforated “U”-shaped third focus electrodes  224  upstream of each first electrode  232 . Further in other embodiment the “U”-shaped third focus electrode  224  can be made of a screen or a mesh.  
         [0097]      FIG. 8C  illustrates third focus electrodes  224  similar to those depicted in  FIG. 8B , except that the third focus electrodes  224  are rotated by 180° to preset a convex surface facing to the first electrodes  232  in order to focus and direct the field of ions and airflow from the first electrode  232  toward the second electrode  242 . These third focus electrodes  224  shown in  FIGS. 8A-8C  are located along extension lines A, B, C similar to previously described embodiments.  
         [0098]    
       FIGS. 9A-9C 
     
         [0099]      FIG. 9A  illustrates a pin-ring configuration of the electrode assembly  220 . The electrode assembly  220  contains a cone-shaped or triangular-shaped first electrode  232 , a ring-shaped second electrode  242  downstream of the first electrode  232 , and a third focus electrode  250  upstream of the first electrode  232 . The third focus electrodes  250  may be electrically connected to the high voltage generator  170 . Preferably the focus electrode  250  is spaced from the first electrode  232  a distance that is in accordance with the other embodiments described herein. Alternatively, the third focus electrode  250  can have a floating potential. As indicated by phantom elements  232 ′,  242 ′, the electrode assembly  220  can comprise a plurality of such pin-like and ring-like elements. The plurality of pin-ring configurations as depicted in  FIG. 9A  can be positioned one above the other along the elongated housing of the invention. Such a plurality of pin-ring configurations can of course operate in another embodiment without the third focus electrode. It is understood that this plurality of pin-ring configurations can be upstanding and elongated along the elongated direction of said housing and can replace the first and second electrodes shown, for example, in  FIG. 2B  and be removable much as the second electrode in  FIG. 2B  is removable. Preferably, the first electrode  232  is tungsten, and the second electrode  242  is stainless steel. Typical dimensions for the embodiment of  FIG. 9A  are L 1 ≈10 millimeters, X 1 ≈9.5 millimeters, T≈0.5 millimeters and the diameter of the opening  246 ≈12 millimeters.  
         [0100]     The electrical properties and characteristics of the third focus electrode  250  is similar to the third focus electrode  224  described in previous embodiments. In contrast to the rod-shaped physical characteristic of the previous embodiments, the shape the third focus electrode  250  is a concave disc, with the concave surface preferably facing toward the second electrodes  242 . The third focus electrode  250  preferably has holes extending therethrough to minimize the disruption in airflow. It is within the scope of the present invention for the third focus electrode  250  to comprise other shapes such as, but not limited to, a convex disc a parabolic disc, a spherical disc, or other convex or concave shapes or a rectangle, or other planar surface and be within the spirit and scope of the invention. The diameter of the third focus electrode  250  is preferably at least fifteen times greater than the diameter of the first electrode  232 . The focus electrode  250  can also be made of a screen or a mesh.  
         [0101]     The second electrode  242  has an opening  246 . The opening  246  is preferably circular in this embodiment. It is within the scope of the present invention that the opening  246  can comprise other shapes such as, but not limited to, rectangular, hexagonal or octagonal. The second electrode  242  has a collar  247  (see  FIG. 9B ) surrounding the opening  246 . The collar  247  attracts the dust contained within the airstream passing through the opening  246 . As seen in the  FIGS. 9B and 9C  the collar  247  includes a downstream extending tubular portion  248  which can collect particles. As a result, the airstream emitted by the electrode assembly  220  has a reduced dust content.  
         [0102]     Other similar pin-ring embodiments are shown in  FIGS. 9B-9C . For example, the first electrode  232  can comprise a rod-shaped electrode having a tapered end. In  FIG. 9B , a detailed cross-sectional view of the central portion of the second electrode  242  in  FIG. 9A  is shown. Preferably, the collar  247  is positioned in relation to the first electrode  232 , such that the ionization paths from the distal tip of the first electrode  232  to the collar  247  have substantially equal path lengths. Thus, while the distal tip (or emitting tip) of the first electrode  232  is advantageously small to concentrate the electric field, the adjacent regions of the second electrode  242  preferably provide many equidistant inter-electrode paths. The lines drawn in phantom in  FIGS. 9B and 9C  depict theoretical electric force field lines emanating from the first electrode  232  and terminating on the curved surface of the second electrode  242 . Preferably, the bulk of the field emanates within about 45 degrees of coaxial axis between the first electrode  232  and the second electrode  242 .  
         [0103]     In  FIG. 9C , one or more first electrodes  232  are replaced by a conductive block  232 ″ of carbon fibers, the block having a distal surface in which projecting fibers  233 - 1 , . . .  233 -N take on the appearance of a “bed of nails.” The projecting fibers can each act as an emitter electrode and provide a plurality of emitting surfaces. Over a period of time, some or all of the electrodes will literally be consumed, where upon the block  232 ″ may be replaced. Materials other than graphite maybe used for block  232 ″ providing that the material has a surface with projecting conductive fibers such as  233 -N.  
         [0104]     Electrode Assembly with a Downstream Trailing Electrode:  
         [0105]    
       FIGS. 10A-10D 
     
         [0106]      FIGS. 10A-10C  illustrate an electrode assembly  220  having an array of trailing electrodes  245  added to an electrode assembly  220  similar to that shown in  FIG. 7A . It is understood that an alternative embodiment similar to  FIG. 10A  can include a trailing electrode or electrodes without any focus electrodes and be within the spirit and scope of the inventions. Referring now to  FIGS. 10A-10B , each trailing electrode  245  is located downstream of the second array of electrodes  240 . Preferably, the trailing electrodes are located downstream from the second electrodes  242  by at least three times the radius R 2  (see  FIG. 10B ). Further, the trailing electrodes  245  are preferably directly downstream of each second electrode  242  so as not to interfere with the flow of air. Also, the trailing electrode  245  is aerodynamically smooth, for example, circular, elliptical, or teardrops shaped in cross-section so as not to unduly interfere with the smoothness of the airflow thereby. In a preferred embodiment, the trailing electrodes  245  are electrically connected to the same outlet of the high voltage generator  170  as the second array of electrodes  240 . As shown in  FIG. 10A , the second electrodes  242  and the trailing electrodes  245  have a negative electrical charge. This arrangement can introduce more negative charges into the air stream. Alternatively, the trailing electrodes  245  can have a floating potential if they are not electrically connected. The trailing electrodes  245  can also be grounded in other embodiments. Further alternatively, as shown in  FIG. 10D , the trailing electrode  245  can be formed with the second electrode out of a sheet of metal formed in the shape of the second electrode and then extending to the position of the trailing electrode and formed as a hollow trailing electrode with a peripheral wall that is about the shape of the outer surface of the trailing electrode  245  depicted in  FIG. 10C .  
         [0107]     When the trailing electrodes  245  are electrically connected to the high voltage generator  170 , the positively charged particles within the airflow are also attracted to and collect on, the trailing electrodes. In a typical electrode assembly with no trailing electrode  245 , most of the particles will collect on the surface area of the second electrodes  242 . However, some particles will pass through the unit  200  without being collected by the second electrodes  242 . Thus, the trailing electrodes  245  serve as a second surface area to collect the positively charged particles. The trailing electrodes  245  also can deflect charged particles toward the second electrodes.  
         [0108]     The trailing electrodes  245  preferably also emit a small amount of negative ions into the airflow. These negative ions will neutralize the positive ions emitted by the first electrodes  232 . If the positive ions emitted by the first electrodes  232  are not neutralized before the airflow reaches the outlet  260 , the outlet fins  212  can become electrically charged and particles within the airflow may tend to stick to the fins  212 . If this occurs, eventually the amount of particles collected by the fins  212  will block or minimize the airflow exiting the unit  200 .  
         [0109]      FIG. 10C  illustrates another embodiment of the electrode assembly  200 , having trailing electrodes  245  added to an embodiment similar to that shown in  FIG. 7C . The trailing electrodes  245  are located downstream of the second array  240  similar to the previously described embodiments above. It is within the scope of the present invention to electrically connect the trailing electrodes  245  to the high voltage generator  170 . As shown in  FIG. 10C , all of the third focus electrodes  224  are electrically connected to the high voltage generator  170 . In a preferred embodiment, only the third focus electrodes  224   a   1 ,  224   b   1  are electrically connected to the high voltage generator  170 . The third focus electrodes  224   a   2 ,  224   b   2  have a floating potential.  
         [0110]     Electrode Assemblies with Various Combinations of Focus Electrodes, Trailing Electrodes and Enhanced Second Electrodes with Protective Ends:  
         [0111]    
       FIGS. 11A-11D 
     
         [0112]      FIG. 11A  illustrates an electrode assembly  220  that includes a first array of electrodes  230  having two wire-shaped electrodes  232 - 1 ,  232 - 2  (generally referred to as “electrode  232 ”) and a second array of electrodes  240  having three “U”-shaped electrodes  242 - 1 ,  242 - 2 ,  242 - 3  (generally referred to as “electrode  242 ”). This configuration is in contrast to, for example, the configurations of  FIG. 9A , wherein there are three first emitter electrodes  232  and four second collector electrodes  242 .  
         [0113]     Upstream from each first electrode  232 , at a distance X 2 , is a third focus electrode  224 . Each third focus electrode  224   a ,  224   b  is at an angle with respect to a first electrode  232 . For example, the third focus electrode  224   a  is preferably along a line extending from the middle of the nose  246  of the second electrode  242 - 2  through the center of the first electrode  232 - 1 , as shown by extension line A. The third focus electrode  224   a  is in-line and symmetrically aligned with the first electrode  232 - 1  along extension line A. Similarly, the third focus electrode  224   b  is located along a line extending from middle of the nose  246  of the second electrode  242 - 2  through the center of the first electrode  232 - 2 , as shown by extension line B. The third focus electrode  224   b  is in-line and symmetrically aligned with the first electrode  232 - 2  along extension line B. As previously described, the diameter of each third focus electrode  224  is preferably at least fifteen times greater than the diameter of the first electrode  232 .  
         [0114]     As shown in  FIG. 11A , and similar to the embodiment shown in  FIG. 5B , each second electrode preferably has a protective end  241 . In a preferred embodiment, the third focus electrodes  224  are electrically connected to the high voltage generator  170  (not shown). It is within the spirit and scope of the invention to not electrically connect the third focus electrodes  224 .  
         [0115]      FIG. 11B  illustrates that multiple third focus electrodes  224  may be located upstream of each first emitter electrode  232 . For example, the third focus electrode  224   a   2  is in-line and symmetrically aligned with the third focus electrode  224   a   1  along extension line A. Similarly, the third focus electrode  224   b   2  is in-line and symmetrically aligned with the third focus electrode  242   b   1  along extension line B. It is within the scope of the present invention to electrically connect all, or none of, the third focus electrodes  224  to the high-voltage generator  170 . In a preferred embodiment, only the third focus electrodes  224   a   1 ,  224   b   1  are electrically connected to the high voltage generator  170 , with the third focus electrodes  224   a   2 ,  224   b   2  having a floating potential.  
         [0116]      FIG. 11C  illustrates that the electrode assembly  220  shown in  FIG. 11A  may also include a trailing electrode  245  downstream of each second electrode  242 . Each trailing electrode  245  is in-line with the second electrode so as not to interfere with airflow past the second electrode  242 . Each trailing electrode  245  is preferably located a distance downstream of each second electrode  242  equal to at least three times the width W of the second electrode  242 . It is within the scope of the present invention for the trailing electrode to by located at other distances downstream. The diameter of the trailing anode  245  is preferably no greater than the width W of the second electrode  242  to limit the interference of the airflow coming off the second electrode  242 .  
         [0117]     One aspect of the trailing electrode  245  is to direct the air trailing off the second electrode  242  and provide a more laminar flow of air exiting the outlet  260 . Another aspect of the trailing electrode  245  is to neutralize the positive ions generated by the first array  230  and collect particles within the airflow. As shown in  FIG. 11C , each trailing electrode  245  is electrically connected to a second electrode  242  by a conductor  248 . Thus, the trailing electrode  245  is negatively charged, and serves as a collecting surface, similar to the second electrode  242 , attracts the positively charged particles in the airflow. As previously described, the electrically connected trailing electrode  245  also emits negative ions to neutralize the positive ions emitted by the first electrodes  232 .  
         [0118]      FIG. 11D  illustrates that a pair of third focus electrodes  224  may be located upstream of each first electrode  232 . For example, the third focus electrode  224   a   2  is upstream of the third focus electrode  224   a   1  so that the third focus electrodes  224   a   1 ,  224   a   2  are in-line and symmetrically aligned with each other along extension line A. Similarly, the third focus electrode  224   b   2  is in line and symmetrically aligned with the third focus electrode  224   b   1  along extension line B. As previously described, preferably only the third focus electrodes  224   a   1 ,  224   b   1  are electrically connected to the high voltage generator  170 , while the third focus electrodes  224   a   2 ,  224   b   2  have a floating potential. It is within the spirit and scope of the present invention to electrically connect all, or none, of the third focus electrodes to the high voltage generator  170 .  
         [0119]     Electrode Assemblies with Second Collector Electrodes having Interstitial Electrodes:  
         [0120]    
       FIGS. 11E-11F 
     
         [0121]      FIG. 11E  illustrates another embodiment of the electrode assembly  220  with an interstitial electrode  246 . In this embodiment, the interstitial electrode  246  is located midway between the second electrodes  242 . For example, the interstitial electrode  246   a  is located midway between the second electrodes  242 - 1 ,  242 - 2 , while the interstitial electrode  246   b  is located midway between second electrodes  242 - 2 ,  242 - 3 . Preferably, the interstitial electrode  246   a ,  246   b  are electrically connected to the first electrodes  232 , and generate an electrical field with the same positive or negative charge as the first electrodes  232 . The interstitial electrode  246  and the first electrode  232  then have the same polarity. Accordingly, particles traveling toward the interstitial electrode  246  will be repelled by the interstitial electrode  246  towards the second electrodes  242 . Alternatively, the interstitial electrodes can have a floating potential or be grounded.  
         [0122]     It is to be understood that interstitial electrodes  246   a ,  246   b  may also be closer to one second collector electrode than to the other. Also, the interstitial electrodes  246   a ,  246   b  are preferably located substantially near or at the protective end  241  or ends of the trailing sides  244 , as depicted in  FIG. 11E . Still further the interstitial electrode can be substantially located along a line between the two trailing portions or ends of the second electrodes. These rear positions are preferred as the interstitial electrodes can cause the positively charged particle to deflect towards the trailing sides  244  along the entire length of the negatively charged second collector electrode  242 , in order for the second collector electrode  242  to collect more particles from the airflow.  
         [0123]     Still further, the interstitial electrodes  246   a ,  246   b  can be located upstream along the trailing side  244  of the second collector electrodes  244 . However, the closer the interstitial electrodes  246   a ,  246   b  get to the nose  246  of the second electrode  242 , generally the less effective interstitial electrodes  246   a ,  246   b  are in urging positively charged particles toward the entire length the second electrodes  242 . Preferably, the interstitial electrodes  246   a ,  246   b  are wire-shaped and smaller or substantially smaller in diameter than the width “W” of the second collector electrodes  242 . For example, the interstitial electrodes can have a diameter of, the same as, or on the order, of the diameter of the first electrodes. For example, the interstitial electrodes can have a diameter of one-sixteenth of an inch. Also, the diameter of the interstitial electrodes  246   a ,  246   b  is substantially less than the distance between second collector electrodes, as indicated by Y 2 . Further the interstitial electrode can have a length or diameter in the downstream direction that is substantially less than the length of the second electrode in the downstream direction. The reason for this size of the interstitial electrodes  246   a ,  246   b  is so that the interstitial electrodes  246   a ,  246   b  have a minimal effect on the airflow rate exiting the device  100  or  200 .  
         [0124]      FIG. 11F  illustrates that the electrode assembly  220  in  FIG. 11E  can include a pair of third electrodes  224  upstream of each first electrode  232 . As previously described, the pair of third electrodes  224  are preferably in-line and symmetrically aligned with each other. For example, the third electrode  224   a   2  is in-line and symmetrically aligned with the third electrode  224   a   1  along extension line A. Extension line A preferably extends from the middle of the nose  246  of the second electrode  242 - 2  through the center of the first electrode  232 - 1 . As previously disclosed, in a preferred embodiment, only the third electrodes  224   a   1 ,  224   b   1  are electrically connected to the high voltage generator  170 . In  FIG. 11F , a plurality of interstitial electrode  296   a  and  246   b  are located between the second electrodes  242 . Preferably these interstitial electrodes are in-line and have a potential gradient with an increasing voltage potential on each successive interstitial electrode in the downstream direction in order to urge particles toward the second electrodes. In this situation the voltage on the interstitial electrodes would have the same sign as the voltage of the first electrode  232 .  
         [0125]     Electrode Assembly with an Enhanced First Emitter Electrode Being Slack:  
         [0126]    
       FIGS. 12A-12C 
     
         [0127]     The previously described embodiments of the electrode assembly  220  include a first array of electrodes  230  having at least one wire-shaped electrode  232 . It is within the scope of the present invention for the first array of electrodes  230  to contain electrodes consisting of other shapes and configurations.  
         [0128]      FIG. 12A  illustrates that the first array of electrodes  230  may include curved wire-shaped electrodes  252 . The curved wire-shaped electrode  252  is an ion emitting surface and generates an electric field similar to the previously described wire-shaped electrodes  232 . Also similar to previous embodiments, each second electrode  242  is “downstream,” and each third focus electrode  224  is “upstream,” to the curved wire-shaped electrodes  252 . The electrical properties and characteristics of the second electrode  242  and the third focus electrode  224  are similar to the previously described embodiment shown in  FIG. 5A . It is to be understood that an alternative embodiment of  FIG. 12A  can exclude the focus electrodes and be within the spirit and scope of the invention.  
         [0129]     As shown in  FIG. 12A , positive ions are generated and emitted by the first electrode  252 . In general, the quantity of negative ions generated and emitted by the first electrode is proportional to the surface area of the first electrode. The height Z 1  of the first electrode  252  is equal to the height Z 1  of the previously disclosed wire-shaped electrode  232 . However, the total length of the electrode  252  is greater than the total length of the electrode  232 . By way of example only, and in a preferred embodiment, if the electrode  252  was straightened out the curved or slack wire electrode  252  is 15-30% longer than a rod or wire-shaped electrode  232 . The electrode  252  is allowed to be slack to achieve the shorter height Z 1 . When a wire is held slack, the wire may form a curved shape similar to the first electrode  252  shown in  FIG. 12A . The greater total length of the electrode  252  translates to a larger surface area than the wire-shaped electrode  232 . Thus, the electrode  252  will generate and emit more ions than the electrode  232 . Ions emitted by the first electrode array attach to the particulate matter within the airflow. The charged particulate matter is attracted to, and collected by, the oppositely charged second collector electrodes  242 . Since the electrodes  252  generate and emit more ions than the previously described electrodes  232 , more particulate matter will be removed from the airflow.  
         [0130]      FIG. 12B  illustrates that the first array of electrodes  230  may include flat coil wire-shaped electrodes  254 . Each flat coil wire-shaped electrode  254  also has a larger surface area than the previously disclosed wire-shaped electrode  232 . By way of example only, if the electrode  254  was straightened out, the electrode  254  will have a total length that is preferably 10% longer than the electrode  232 . Since the height of the electrode  254  remains at Z 1 , the electrode  254  has a “kinked” configuration as shown in  FIG. 12B . This greater length translates to a larger surface area of the electrode  254  than the surface area of the electrode  232 . Accordingly, the electrode  254  will generate and emit a greater number of ions than electrode  232 . It is to be understood that an alternative embodiment of  FIG. 12B  can exclude the focus electrodes and be within the spirit and scope of the invention.  
         [0131]      FIG. 12C  illustrates that the first array of electrodes  230  may also include coiled wire-shaped electrodes  256 . Again, the height Z 1  of the electrodes  256  is similar to the height Z 1  of the previously described electrodes  232 . However, the total length of the electrodes  256  is greater than the total length of the electrodes  232 . In a preferred embodiment, if the coiled electrode  256  was straightened out the electrodes  256  will have a total length two to three times longer than the wire-shaped electrodes  232 . Thus, the electrodes  256  have a larger surface area than the electrodes  232 , and generate and emit more ions than the first electrodes  232 . The diameter of the wire that is coiled to produce the electrode  256  is similar to the diameter of the electrode  232 . The diameter of the electrode  256  itself is preferably 1-3 mm, but can be smaller in accordance with the diameter of first emitter electrode  232 . The diameter of the electrode  256  shall remain small enough so that the electrode  256  has a high emissivity and is an ion emitting surface. It is to be understood that an alternative embodiment of  FIG. 12C  can exclude the focus electrodes and be within the spirit and scope of the invention.  
         [0132]     The electrodes  252 ,  254  and  256  shown in  FIGS. 12A-12C  maybe incorporated into any of the electrode assembly  220  configurations previously disclosed in this application.  
         [0133]     The foregoing description of the preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. Modifications and variations maybe made to the disclosed embodiments without departing from the subject and spirit of the invention as defined by the following claims. Embodiments were chosen and described in order to best describe the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention, the various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.