Abstract:
An air cleaning device has a housing with at least one input aperture and at least one output aperture, and an air channel therebetween. A first collection plate has a first wall with first inside edges and first outside edges, and has a first charge applied thereto. A second collection plate has a second wall with second inside edges and second outside edges, and has a second charge applied thereto. The second collection plate is housed in a first space between the first inside edges of the first collection plate. A third collection plate has a third charge applied thereto. The third collection plate is housed in a second space between the second inside edges of the second collection plate. A set of charged wires are located outside the first collection plate so as to create an electrostatic field within the housing. The electrostatic field ionizes incoming air. A fan creates a flow of air into the at least one input aperture and out the at least one output aperture.

Description:
RELATED APPLICATION  
       [0001]     This application claims priority to Provisional Patent Application Ser. No. 60/584,192, entitled Ultraviolet Art Purifier Having Multiple Charged Collection Plates, filed Jun. 30, 2004. 
     
    
     BACKGROUND  
       [0002]     1. Technical Field  
         [0003]     The invention relates to air purifiers, and more specifically, to air purifiers utilizing multiple charged collection plates and a germicidal light to clean air circulating through the air purifier.  
         [0004]     2. Description of the Related Arts  
         [0005]     There are air purifiers known in the art. For example, one model made by Sharper Image uses electro-kinetic energy to cause air to circulate through the air purifier. The model includes an electro-kinetic transducer to convert energy into ion flow, causing the air to flow through the air purifier. Such model also includes a germicidal Ultraviolet (“UV”) lamp to clean the air. This type of air purifier creates an electrostatic field and polarizes air entering into the purifier. Air enters through the bottom of the air purifier, and circulates up through the purifier and out an opening near the top of the purifier. As the air flows upward within the air purifier, it passes the germicidal UV lamp, which kills some bacteria within the flowing air. This model employs a single electrostatic field and a single air filter. Particles attach themselves only to the outside edge of the air filter.  
         [0006]     Another air purifier model is made by Honeywell. In the Honeywell model, air enters the air purifier at a location near the bottom and exits at a location near the top. This model includes a single air filter. The air stream within the purifier is subjected to a single electrostatic field, generated by a wire on a single surface within the purifier, and particles within the air stream attach themselves only to the outside edge of the air filter.  
       SUMMARY OF THE INVENTION  
       [0007]     One embodiment of the invention is directed to an air cleaning device which has a housing having at least one input aperture and at least one output aperture, and an air channel therebetween. A first collection plate has a first wall with first inside edges and first outside edges, and has a first charge applied thereto. A second collection plate has a second wall with second inside edges and second outside edges, and has a second charge applied thereto. The second collection plate is housed in a first space between the first inside edges of the first collection plate. A third collection plate has a third charge applied thereto. The third collection plate is housed in a second space between the second inside edges of the second collection plate. A set of charged wires are located outside the first collection plate so as to create an electrostatic field within the housing. The electrostatic field ionizes incoming air. A fan creates a flow of air into the at least one input aperture and out the at least one output aperture. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  illustrates a side view of an air purifier according to an embodiment of the invention;  
         [0009]      FIG. 2  illustrates a front view of the air purifier according to an embodiment of the invention;  
         [0010]      FIG. 3  illustrates a view of the top of the air purifier according to an embodiment of the invention;  
         [0011]      FIG. 4  illustrates an exploded diagram of a small air collection plate, a medium-sized air collection plate, and a large collection plate according to an embodiment of the invention;  
         [0012]      FIG. 5  illustrates a partial cross-section area of the air purifier, illustrating a cross-section of all components between the large collection plate and the outer wall of the main body according to an embodiment of the invention;  
         [0013]      FIG. 6  is a cross-sectional block diagram of half of the air purifier according to an embodiment of the invention;  
         [0014]      FIG. 7  illustrates an exploded diagram of the air purifier according to an embodiment of the invention;  
         [0015]      FIG. 8  illustrates a cross-sectional view of the air purifier according to an embodiment of the invention; and  
         [0016]      FIG. 9  illustrates a method of cleaning air according to an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     The invention is directed to an air purifier. In the most general form, the air purifier includes a housing that retains a fan or blower, an ionization unit, a permanent filtration assembly, and a germicidal ultraviolet (UV) lamp.  
         [0018]     In operation, the fan or blower draws air into and forces air circulation through the housing. This forced air circulation creates a suction that draws additional air into the air purifier through one or more inlet ports and a back pressure that forces the air out of the air purifier though one or more discharge ports.  
         [0019]     The air purifier includes three collection plates for trapping particles within the air. The three collection plates may each be formed of a conductive material such as aluminum. The three collection plates may have different sizes—a small collection plate may be housed between the walls of a medium-sized air collection plate, and the medium-sized collection plate may in turn be housed between the walls of a large collection plate. The walls of the large collection plate may be negatively charged, the walls of the medium-sized collection plate may be positively charged, and the walls of the small collection plate may be negatively charged.  
         [0020]     When air is drawn into the air purifier, it passes by the ionization unit. The ionization unit creates a charged electrostatic field that ionizes the air molecules and particulate matter entrained therein. The ionization process results in negative and positive ions and neutral-charged molecules and particles.  
         [0021]     The removable permanent filtration assembly comprises one or more charged collection plates for collecting oppositely charged ions and particles that flow through the air purifier. The collection plates may be positioned adjacent, concentric or contiguous to one another. The collection plates may also be positioned and charged such that a negatively charged plate is adjacent, concentric or contiguous to a positively charged plate or vice versa. This arrangement permits at least one collection plate of the permanent filtration assembly and the ionization unit to trap charged particles shortly after the air stream enters the air purifier. For example, some of the charged ions and particles may be attracted to and stick onto the closest oppositely charged collection plate. Likewise, some of the charged ions and particles may be attracted to and stick onto the ionization unit if oppositely charged. The rest of the air, i.e., neutral particles, molecules and charged particles that are not trapped by the ionization unit or the collection plate, is forced up to the top of the air purifier.  
         [0022]     In one embodiment, as the air is forced upward, UV light from a germicidal UV lamp irradiates the air stream with UV light rays. The ultraviolet lamp neutralizes certain airborne bacteria, mold and viruses another particles entrained therein. Once at the top of the air purifier, the air is then forced back down the air purifier and is eventually forced out of the housing through the discharge port.  
         [0023]     As the air flows back downward, UV light from the germicidal lamp continues to shine on the air, destroying or diminishing the amount of bacteria or other particles in the air. Also, charged particles in the air may attach themselves to one or more of the collection plates. Once at the bottom of the air purifier, a fan blows the cleaned air out of the air purifier.  
         [0024]     Turning now to an illustrated embodiment of the invention,  FIG. 7 , shows an exploded of an air purifier  100  designed in accordance with the teaching of this invention. As best seen in  FIGS. 1, 4  and  7 , the air purifier  100  includes a housing  115  that retains a fan or blower  605 , an ionization unit  495 , a permanent filtration assembly  395 , and a germicidal UV lamp assembly  700 .  
         [0025]      FIG. 1  illustrates a side view of an air purifier  100 . The air purifier  100  may be powered by AC power from a standard AC outlet; in other embodiments, the air purifier  100  may be powered from a DC power source such as batteries.  
         [0026]     As best seen in  FIG. 1 , the housing  115  may have a generally cylindrical shape, and may be formed of a material such as a hard plastic. The housing  115  may be comprised of three sections—a top section  155 , a main body  150 , and a base portion  160 . The main body portion  150  defines one or more inlet apertures  105 . As shown in  FIG. 1 , the inlet apertures  105  may be located on the bottom half of the main body  150 , each of which may extend in a vertical direction. The inlet apertures  105  may be located at a plurality of locations wrapping around the cylindrical shape of the housing  115 , so as to draw in air from substantially all directions.  
         [0027]     The housing  115  also defines one or more outlet apertures  110 . As best seen in  FIG. 1 , the outlet apertures  110  may be formed on the base formed on the  160  at a position below the inlet apertures  105 .  
         [0028]      FIG. 2  illustrates a front view of the air purifier  100 . As best seen in  FIGS. 2 and 3 , the top section  155  may support a power button/switch  130  for activating the air purifier  100 . For example, the power button/switch  130  may be depressed to active the air purifier  100 . The top section  155  may also support a speed control button/switch  135 . The speed control button/switch  135  permits the air purifier  100  to operate at three different speeds. For example, the speed control button/switch  135  may be depressed once to initiate a “slow speed” setting, twice to initiate a “medium speed” setting, and three times to initiate a “fast speed” setting. In other embodiments, the air purifier  100  may operate at more or fewer than three speeds. The top section  155  may also support an auto-off timer function to shut off the unit after increments of time such as, e.g., 2-hr, 4-hr, or 8-hr. The auto-off timer function may be implemented by a timer button/switch  125  and timing control circuitry within the air purifier  100 . The top section  155  supports a depressible button  120  which, when depressed, allows the top of the air purifier  100  to be opened, thus permitting access to components located within the housing  115 .  
         [0029]     As best seen in  FIG. 3 , the top surface of the top section  155  supports light indicating devices  300  such as Light Emitting Diodes (“LEDs”). The light indicating devices  300  may be lit during operation to indicate that the air purifier  100  is turned “on” and is operating properly. The top surface of top section  155  may also support a UV on/off button/switch  195  to activate or turn off the germicidal UV lamp.  
         [0030]      FIG. 4  illustrates an exploded diagram of a small collection plate  410 , a medium-sized collection plate  405 , and a large collection plate  400  for trapping particles entrained in the air stream. The three collections plates  400 ,  405 , and  410  may be arranged such that the small collection plate  410  may be housed between the walls of the medium-sized collection plate  405 , and the medium-sized collection plate  405  may in turn be housed between the walls of the large collection plate  400 . The three collection plates  400 ,  405 , and  410  may each be formed of a conductive material such as aluminum.  
         [0031]     As best seen in  FIG. 6 , the walls of the collection plates  400 ,  405  and  410  may support an electric charge. For example, the walls of the large collection plate  400  may be negatively charged, the walls of the medium-sized collection plate  405  may be positively charged, and the walls of the small collection plate  410  may be negatively charged. Air circulating within the air stream through the air purifier  100  may contain charged particles such as dust. A function of the air purifier  100  is to remove these charged particles from the air stream by attracting the particles to the charged collection plates  400 ,  405 , and  410 .  
         [0032]     The collection plates  400 ,  405 , and  410  may be cleaned by opening up the air purifier  100  by rotating the top section  155  ( FIG. 2 ) and reaching in and pulling out the collection plates  400 ,  405 , and  410  residing within the main body  150 . Each of the collection plates  400 ,  405 , and  410  may then be wiped with a damp cloth to remove dust and other particles stuck attached thereto. Tap water may be utilized to moisten the cloth. After sufficient drying time, the collection plates  400 ,  405 , and  410  may be reinserted.  
         [0033]     As best seen in  FIG. 4 , the collection plates  400 ,  405  and  410  may be cylindrically shaped and concentrically arranged. One advantage of the cylindrical shape of the collection plates  400 ,  405  and  410  is that an increased surface area is provided for particle collection. For example, test results for one embodiment of the air purifier  100 , report that the cylindrically shaped collection plates  400 ,  405  and  410  provide approximately five times the particle collection surface area and traps approximately two times the pollutants captured by leading air purifiers that use a flat metal sheet as the particle collector.  
         [0034]     Turning now to  FIG. 4 , the large collection plate  400  has a large cover  415  that fits on the top end of the large collection plate  400 . A large holder  420  and a set of connectors  425  are used to secure the large collection plate  400  to the main body  150  near the bottom of the main body  150 . The medium-sized collection plate  405  has a medium-sized cover  430  that fits on the top end of the medium-sized collection plate  405 . A medium-sized holder  435  and a set of connectors  440  are used to secure the medium-sized collection plate  405  to the main body  150  near the bottom of the main body  150 . The small collection plate  410  has a small cover  450  which fits on the top end of the small collection plate  410 . A small holder  455  and a connector  460  are used to secure the small collection plate  410  to the main body  150  near the bottom of the main body  150 . A handle  445  is attachable to the small collection plate cover  450 . When the small collection plate  410  is placed within the medium-sized collection plate  405  and the medium-sized collection plate  405  is placed within the large collection plate  400  and the entire combination of collection plates  400 ,  405 , and  410  is placed inside the main body  150  and secured, a knob  465  on the small collection plate cover  450  may extend up through the medium-sized cover  430  and the large cover  415 . The handle  450  may be screwed onto the knob  465 , or attached thereto is some other manner, so as to secure the collection plates  400 ,  405 , and  410  to each other.  
         [0035]      FIG. 5  illustrates a partial cross-sectional area of the air purifier  100 , illustrating a cross-section of all components between the large collection plate  400  and the outer wall of the main body  150 . As illustrated, the ionization unit  499  may include a set of wires  500  that extend vertically between two support plates identified in  FIG. 5  as a middle plate  505  and a lower plate  510 . The wires  500  may be substantially evenly spaced around the circumference of the air purifier  100 . When an electric charged is supplied to the wires  500 , a more uniform electrostatic field may be generated than would be possible if the wires  500  did not extend around the circumference or were only coupled to a single surface.  
         [0036]     The wires  500  may be formed of tungsten, for example. Specifically, the wires  500  may be formed of stainless tungsten, and in other embodiments, the wires  500  may be formed of tungsten coated with gold, or any other suitable conductive material. The middle plate  505  and the lower plate  510  may each be formed of a metal material such as aluminum or stainless steel, for example.  
         [0037]     As best seen in  FIG. 7 , a scraper  515  may also be positioned parallel to the middle plate  505  and the lower plate  510 . The scraper  515  may include a support plate that defines a plurality of apertures. Each aperture may be sized to receive of the wires comprising the wires  500 . The scraper  515  may also include a member  520  for cleaning the wires  500 . For example, the member  520  may be movably attached to a portion of the scraper  515  using known techniques such that the member  520  is accessible on the exterior surface of the air purifier  100 . By pushing down or pulling up on the member  520 , a user may move the scraper  515  in upward and downward directions. For example, moving the scraper  515  permits cleaning of the wires  500 , i.e., the removal of dust and other particles that periodically attach themselves to the wires  500 .  
         [0038]     Once the air arrives up near the germicidal lamp  600 , it flows back down via one of two pathways. For the described embodiment, the first pathway is between the inside edge of the negatively charged large collection plate collection plate  400  and the outside edge of the positively charged medium-sized collection plate collection plate  405 . The second pathway is between the inside edge of the positively medium-sized collection plate collection plate  405  and the outside edge of the negatively charged small collection plate collection plate  410 . As the air flows down on of these paths, negatively charged particles in the air attached themselves to the positively charged medium sized collection plate collection plate  405  and positively charged particles in the air attached themselves to either the inner edge of the large collection plate collection plate  400  or the outside edge of the small collection plate collection plate  410 . The collection plates  400 ,  405 , and  410  may receive their respective charges from the base  160  of the air purifier  100 , where they may be secured.  
         [0039]     Once the air reaches the bottom of the collection plates  400 ,  405 , and  410 , a fan  605  blows the air out of the outlet aperture  110  and back into the area in which air is being cleaned. When the fan  605  blows air out of the outlet aperture  110  of the air purifier  100 , new air is drawn into the inlet aperture  105  by the resulting suction.  
         [0040]     Referring again to  FIG. 7 , this figure illustrates an exploded diagram of the air purifier  100 , and more particularly the germicidal UV lamp assembly  700 . The UV lamp assembly  700  includes a UV lamp  600  supported with a UV reflector  726  using conventional techniques. The UV reflector  736  is supported with a top bottom  720 , wherein the top bottom  720  is coupled to the top cover  704 . For instance, the top bottom  720  may be coupled to the top cover  704  via screws. Additionally, a UV lens  722  and a UV jack  724  are positioned between the reflector  726  and the top bottom  720 .  
         [0041]     The UV assembly  700  also includes a lamp holder  728  positioned directly below the UV lamp  600 . The lamp holder  728  may be held in place by a holder screw  729 . The UV assembly  700  also includes a transformer  710  and a UV inverter  712  located beneath the top cover  704 . The UV lamp  600  requires a relatively high frequency to start; the UV inverter  712  supplies this high frequency. The UV assembly  700  also include safe knob  718  that may be utilized to prevent power from reaching the germicidal UV lamp  600  when the light bulb is being replaced.  
         [0042]     Referring to  FIGS. 2 and 7 , to insert or replace the germicidal UV lamp within the air purifier  100 , the air purifier  100  may be “opened up” by rotating the top section  155  along the hinge, exposing the internal components within the body of the air purifier  100 . The UV lamp  600  may then be removed.  
         [0043]      FIG. 7  also provides additional detail regarding the button  120  previously discussed with respect to  FIG. 2 . The button  120 , which allows the user to open up the top portion  155  of the air purifier, may be comprised of a locking piece  707 , a spring  706  and a fix plate  705 . The button  120  may be located within an aperture  708  on the top cover  704 .  
         [0044]      FIG. 7  further illustrates that the light emitting devices  300 , the speed button/switch  135 , the power button/switch  130 , and the timer button/switch  125  may be located beneath the top cover  704 . The light emitting devices  300  may be mounted on a main printed circuit board (“PCB”)  714 , which may be coupled to a power PCB  716 .  
         [0045]      FIG. 7  also illustrates further detail concerning the housing  115 . The main body  150  of the housing  115  may include a left enclosure  730  and a right enclosure  732 , which together form the outside wall of the air purifier  100 . A unit top  734  may include a hinge  736  coupled to the top cover  704 , that allows the top cover  704  to swivel open. A supporter  742  may be coupled to the unit top  734  and may be coupled to a support groove  744  on the left enclosure  730 . In other embodiments, the support groove  744  may be located on the right enclosure  732 . Directly beneath the unit top  734  is an upper plate  740 . Below the upper plate  740 , the middle plate  505 , the wires  500 , the scraper  515 , and the lower plate  510  may be located. Beneath the lower plate  510  may be a line holder  750  which is used to position each of the wires  500 . A touch plate  752  may be utilized to provide the charges for each of the collection plates  400 ,  405 , and  410 . A panel  755  attaches between the left enclosure  730  and the right enclosure  732  on the front of the main body  150 .  
         [0046]     A base top  760  and a base bottom  762  comprise the base portion  160 . The blower/fan  605  is located between the base top  760  and the base bottom  762 . The fan  605  may be a centrifugal fan of the type commonly used in air purifiers. The fan  605  circulates the air inside the housing  115  along a nonlinear flow path.  
         [0047]     Using the fan  605  to circulate the air through the housing  115  results in an increased clean air delivery rate (CADR) as compared to leading air purifiers that do not use fan/blower air circulation devices. Table 1 reports the CADR for one embodiment of the air purifier  100 . As shown by Table 1, the CADR for the air purifier  100  for the smoke and dust is greater than twice that of leading air purifiers that do not include fan/blower circulation devices, and the CADR for pollen exceeds that of leading air purifiers that do not use fan/blower circulation devices.  
                             TABLE 1                           CADR for an Embodiment of Air Purifier 100                POLLUTANT   CADR                       Smoke   38.2           Dust   39.5           Pollen   38.7                      
 
         [0048]     Additionally, the fan permits greater air circulation through the unit. Test data for one embodiment of the air purifier  100  reports an air circulation rate of 50 CFM compared to 17 CFM for leading air purifiers that do not use fan/blower air circulation devices. Further, test results for one embodiment of the air purifier  100  report an air clean time of approximately 21 minutes for a standard size room as compared to 61 minutes for leading air purifiers that do not use fan/blower air circulation devices.  
         [0049]     The fan  605  may be coupled to a motor housing  764  and a motor  766 . The motor  766  is powered by either a high voltage power supply  770  or power from an electrical outlet via power cord  768 . The motor  766  may include a muffler to quiet the motor  766  during operation.  
         [0050]      FIG. 8  illustrates a cross-sectional view of the air purifier showing the placement of the large collection plate  400 , the medium-sized collection plate  405 , and the small collection plate  410  within the air purifier  100  when the top cover  704  in secured to the main body  150 .  FIG. 8  illustrates the locations of the assembled components shown in the exploded assembly diagram of  FIG. 7 .  
         [0051]     As best illustrated in  FIG. 6 , in one embodiment, the air purifier  100  cleans air drawn into the housing  115  in various stages. For example, air enters the air purifier  100  via the inlet aperture  105 . Once inside the air purifier  100 , the air encounters the positively charged electrostatic field generated by the wires  500 . After encountering the positively charged electrostatic field, the air becomes ionized, creating positive, negative and neutral particles. Some of the positively charged particles attach to the outside of the negatively charged collection plate  400  and some of the negatively charged particles attach to the positively charged wires  500 . The rest of the air is drawn up to the top of the air purifier  100 , between the outer wall of the air purifier and the outside edge of the large air collection plate. Once above the top of the air large collection plate collection plate  400 , the air is then drawn back down the air purifier  100 .  
         [0052]     As the air flows back downward, charged particles in the air may attach themselves to the inner edges of the negatively charged large collection plate collection plate  400 , the inner or outer edges of the positively-charged medium-sized collection plate collection plate  405 , or to the outer edges of the negatively-charged small collection plate collection plate  410 . Once at the bottom of the air purifier  100 , a fan  605  blows the cleaned air out of the air purifier  100 . Upon entering the air purifier  100 , the air flow path inside the air purifier  100  is non-linear and involves several sharp angular turns as best seen in  FIG. 6 .  
         [0053]     As best seen in  FIG. 6 , upon entering the air purifier  100 , the air is drawn into the air purifier  100  along a path that is lateral to the axis of the fan  605 . After passing through the ionization unit  495 , the air flow turn approximately 180° and flows along the longitudinal axis of the main body portion  150  of the air purifier  100  until it reaches the top section  155 . At the top section  155 , the air stream makes another turn of approximately 180° and flows downward along the longitudinal axis of the main body portion  150  and into the base portion  160 . At the base portion  160 , the air stream makes another turn and flows along the lateral axis of the base portion  160 . The air stream flows past (a) the space between the outside edge of the large collection plate and the outer wall of the air purifier  100  on the way up after entering the air purifier  100 , and (b) then back down in the space between either (i) the inner edge of the large collection plate collection plate and outer edge of the medium-sized air collection plate, or (b) the inner edge of the medium-sized collection plate collection plate and the outer edge of the small air collection plate. Consequently, the air stream passes over a larger particle collecting surface area onto which charged particles may attach themselves than would be possible if only a single collection plate were used or if the air stream flowed only in a single direction.  
         [0054]     The air is forced to flow up through a pathway formed between the outside edge of the large collection plate  400  and the outer wall  610  of the air purifier  100 . As it travels upward, the air is subjected to light from the germicidal UV lamp  600 .  
         [0055]      FIG. 9  illustrates one method of cleaning air using the purifier  100  shown in  FIG. 6 . First, air is drawn  900  into the air purifier  100 . The air is subjected  905  to a positively charged electrostatic field generated by the positively charged wires  500 . The positively charged electrostatic field ionizes the air, and negatively charged particles in the air attach themselves to the positively charged wires  500 , and the positively charged particles attached themselves to the outside edges of the large collection plate  400 . The air moves  910  upward toward the germicidal lamp  600 , and light from the germicidal lamp  600  destroys or diminishes an amount of bacteria in the air. Finally, the air is circulated  915  downward through gaps between the positively charged medium-sized collection plate  405  and each of the negatively charged large collection plate  400  and the small collection plate  410 . Charged particles in the air attach themselves to these collection plates, and the rest of the air is then pushed out of the outlet aperture by the fan  605 .  
         [0056]     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of an embodiment of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of an embodiment of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.