Abstract:
A shock and/or vibration damped optical lens assembly for an electronic equipment. The optical lens assembly of the present invention is particularly useful for electronic equipment such as mobile phones, PDA&#39;s, etc. incorporating cameras. By providing a shock and/or vibration damped optical lens assembly allows such devices to more reliably implement auto-focusing and/or zoom lens packages. Accordingly, the present invention facilitates the use of more advanced lens packages in hand-held electronic equipment such as cell phones, PDA&#39;s etc.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to electronic equipment and, more particularly, to electronic equipment that includes optical lens components, and a method of shock damping of optical lens components of an electronic equipment. 
       DESCRIPTION OF THE RELATED ART 
       [0002]    Conventional mobile phones, in addition to providing voice communication capabilities, also provide a number of non-voice related features. For example, mobile phones can be used to surf the internet, play music and videos, transmit and receive messages (e.g., emails and text messages), take and display photographs, as well as a number of other features. 
         [0003]    Mobile phones with camera functions (e.g., camera phones) are popular and are becoming commonplace. By combining a phone with a camera, consumers do not have to carry both devices with them. Camera phones, however, typically do not offer the same level of performance as stand alone digital cameras. Even basic stand-alone digital cameras typically offer auto-focus and optical zoom functionality. Most camera phones, however, use fixed focus lenses and do not offer optical zoom functionality. Accordingly, while camera phones are becoming popular, to most consumers they do not offer a viable alternative to a stand alone digital camera. 
         [0004]    Due to small amount of space available in a phone, improving the performance of the lens assemblies is difficult. In particular, allowing for movement of the lenses for focusing and zooming in such a small space is challenging. 
         [0005]    Another consideration in designing a camera phone is the increased potential for a camera phone to be dropped and/or mishandled, relative to a stand-alone camera, due to the higher frequency of use of mobile phones. Lens assemblies, and in particular auto-focus and zoom lens assemblies with moving lenses, are typically highly sensitive to shock inputs. Shock inputs in the direction of movement of the lenses are typically the most detrimental to a lens assembly and can render the camera inoperative. 
       SUMMARY 
       [0006]    The present invention provides a shock and/or vibration damped optical lens assembly for an electronic equipment. The optical lens assembly of the present invention is particularly useful for electronic equipment such as mobile phones, PDA&#39;s, etc. incorporating cameras. By providing a shock and/or vibration damped optical lens assembly, such devices can more reliably implement auto-focusing and/or zoom lens packages. Accordingly, the present invention facilitates the use of more advanced lens packages in hand-held electronic equipment such as cell phones, PDA&#39;s etc. 
         [0007]    According to one aspect of the invention, there is provided an optical lens assembly for an electronic equipment including a shock absorbing mount within a housing of the electronic equipment, and an optical lens group supported by the shock absorbing mount. The shock absorbing mount permits relative movement between the optical lens group and the electronic equipment to absorb shock energy. 
         [0008]    According to another aspect, the shock absorbing mount includes a sleeve member mountable to the electronic equipment in which an optical lens package including the optical lens group is supported for sliding axial movement relative to the sleeve member. The sleeve member is generally sealed and includes at least one passageway for permitting fluid to flow into and out of the sleeve in response to movement of the optical lens package within the sleeve member. 
         [0009]    According to another aspect, the optical lens package divides the sleeve member into two separate chambers each having a respective passageway for permitting fluid to flow into and out of the respective chambers in response to movement of the optical lens package within the sleeve. Movement of the optical lens package in a first axial direction expels fluid from one chamber and draws fluid into the other chamber. 
         [0010]    According to another aspect, the optical lens package forms a seal with the sleeve member to prevent substantial flow of fluid between the chambers. 
         [0011]    According to another aspect, the passageway includes a flow regulator. 
         [0012]    According to another aspect, the flow regulator is an orifice. 
         [0013]    According to another aspect, the fluid is air. 
         [0014]    According to another aspect, the electronic equipment is a mobile phone. 
         [0015]    According to another aspect, the electronic equipment is at least one of a personal audio device, a personal video device, a camera or a personal digital assistant. 
         [0016]    According to another aspect, the shock absorbing mount includes a sleeve member mountable to the electronic equipment in which an optical lens package including the optical lens group is supported for sliding axial movement relative to the sleeve member. The optical lens package forms a seal with the sleeve member thereby dividing the sleeve member into two separate chambers. At least one passageway connects the separate chambers for permitting fluid to flow between the chambers in response to movement of the optical lens package within the sleeve member. 
         [0017]    According to another aspect, the passageway includes a flow regulator. 
         [0018]    According to another aspect, the flow regulator is an orifice. 
         [0019]    According to another aspect, the fluid is air. 
         [0020]    According to another aspect, the fluid is oil. 
         [0021]    According to another aspect, the oil is silicone oil. 
         [0022]    According to another aspect, the electronic equipment is a mobile phone. 
         [0023]    According to another aspect, the electronic equipment is at least one of a personal audio device, a personal video device, a camera or a personal digital assistant. 
         [0024]    According to another aspect the shock absorbing mount is a barrel of an optical lens package including the optical lens group. The barrel includes at least one chamber, and a passageway permits flow of fluid into and out of the chamber in response to movement of the optical lens package to thereby dampen movement of the optical lens package. 
         [0025]    According to another aspect, the optical lens group divides the barrel into two chambers each having a respective passageway for permitting fluid to flow into and out of the respective chambers in response to movement of the optical lens package within the sleeve. Movement of the optical lens package in a first axial direction expels fluid from one chamber and draws fluid into the other chamber. 
         [0026]    According to another aspect, the optical lens group forms a seal with the barrel to prevent substantial flow of fluid between the chambers. 
         [0027]    According to another aspect, the passageway includes a flow regulator. 
         [0028]    According to another aspect, the flow regulator is an orifice. 
         [0029]    According to another aspect, the fluid is air. 
         [0030]    According to another aspect, the electronic equipment is a mobile phone. 
         [0031]    According to another aspect, the electronic equipment is at least one of a personal audio device, a personal video device, a camera or a personal digital assistant. 
         [0032]    Another aspect of the invention relates to a method of damping an optical lens group of an electronic equipment including supporting the optical lens group for axial movement relative to the electronic component, and damping movement of the optical lens group. 
         [0033]    According to another aspect, the damping includes damping movement of the optical lens group with a fluid. 
         [0034]    According to another aspect, the damping includes configuring the optical lens group so that movement of the optical lens group forces fluid surrounding at least a portion of the optical lens group through a passageway. 
         [0035]    To the accomplishment of the foregoing and the related ends, the invention, then, comprises the features hereinafter fully described in the specification and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but several of the various ways in which the principles of the invention may be suitably employed. 
         [0036]    Other systems, methods, features, and advantages of the invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. 
         [0037]    Although the invention is shown and described with respect to one or more embodiments, it is to be understood that equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications, and is limited only by the scope of the claims. 
         [0038]    Also, although the various features are described and are illustrated in respective drawings/embodiments, it will be appreciated that features of the given drawing or embodiment may be used in one or more other drawings or embodiments of the invention. 
         [0039]    It should be emphasized that the term “comprise/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Likewise, elements and features depicted in one drawing may be combined with elements and features depicted in additional drawings. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0041]      FIG. 1  is an illustration of an exemplary mobile phone. 
           [0042]      FIG. 2  is another view of the mobile phone of  FIG. 1 . 
           [0043]      FIG. 3  is a cross-sectional view taken along the line a-a of  FIG. 2  illustrating an exemplary embodiment of an optical lens assembly in accordance with the present invention. 
           [0044]      FIG. 4  is another cross-sectional view taken along the line a-a in  FIG. 2  illustrating another exemplary embodiment of an optical lens assembly in accordance with the present invention. 
           [0045]      FIG. 5  is a cross-sectional view of the exemplary optical lens assembly of  FIG. 4 . 
           [0046]      FIG. 6  is a cross-sectional view of another exemplary embodiment of an optical lens assembly in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0047]    The present invention will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. 
         [0048]    The term “electronic equipment” includes portable radio communication equipment. The term “portable radio communication equipment,” which hereinafter is referred to as a “mobile radio terminal,” a “mobile phone,” a “mobile device,” or a “mobile terminal” and the like, includes all equipment such as mobile telephones, pagers, communicators, i.e., electronic organizers, personal digital assistants (PDAs), smartphones, portable communication apparatus or the like. The term “electronic equipment” also may include portable digital music and/or video devices, e.g., iPod devices, mp3 players, etc. 
         [0049]    In the present application, the invention is described primarily in the context of a mobile phone. However, it will be appreciated that the invention is not intended to be limited to a mobile phone and can be any type of electronic equipment. 
         [0050]    Referring now to  FIGS. 1 and 2 , a mobile phone  10  is shown as having a “brick” or “block” design type housing  18  (sometimes referred to as a case), but it will be appreciated that other type housings, such as, for example, clam shell or slide-type housings, may be utilized without departing from the scope of the invention. The mobile phone  10  further includes a speaker  20 , display  22 , a navigation switch and selection/function keys or switches  24 , a key pad  26 , a microphone  28 , and an external camera lens  30  of a camera (see,  FIG. 2 ); these are illustrative and exemplary of parts of a typical mobile phone, but it will be appreciated that other parts that are similar or different in form and/or function may be included in the mobile phone  10 . The mobile phones to which the invention pertains also may be of the types that have more or fewer functions, keys, etc., compared to those illustrated and described herein. 
         [0051]    As will be appreciated, the mobile phone  10  may function as a conventional mobile phone. The mobile phone  10  may have additional functions and capabilities that may be developed in the future. From a conventional point of view, the display  22  displays information to a user, such as operating state, time, phone numbers, contact information, various navigational menus, etc., which facilitate and/or enable the user to utilize the various features of the mobile phone. The display also may be used to view movies, images, play games, or as a viewfinder for the camera, for example. Part or all of the display  22  may be a touch screen type device. The navigation and function keys  24  and the keypad  26  may be conventional in that they provide for a variety of user operations. For example, one or more of the function keys and navigation device  24  may be used to navigate through a menu displayed on the display  22  to select different phone functions, profiles, settings, etc., as is conventional. The keypad  26  typically includes one or more special function keys, such as, a “call send” key for initiating or answering a call, a “call end” key for ending or hanging up a call, and dialing keys for dialing a telephone number. Other keys included in the navigation and function keys  24  and/or keypad  26  may include an on/off power key, a web browser launch key, a camera key, a voice mail key, a calendar key, etc. 
         [0052]      FIG. 3  is a cross-sectional view of the phone  10 , taken along the line a-a in  FIG. 2 , illustrating an exemplary optical lens assembly  40  in accordance with an embodiment of the invention. The optical lens assembly  40  includes a shock absorbing mount  42  and an optical lens package  44  supported by the shock absorbing mount  42 . The shock absorbing mount  42  permits relative movement between the optical lens package  44  and the phone  10  to absorb shock energy, such as when the phone is dropped. 
         [0053]    The shock absorbing mount  42  includes a sleeve member  52 , which in the illustrated embodiment is a generally cylindrical sleeve member. The sleeve member  52  has a cylindrical side wall  54  and an end cap  56  at a first end thereof. The opposite end of the cylindrical side wall terminates adjacent to the external camera lens  30 . Supported within the sleeve member  52  is the optical lens package  44 . 
         [0054]    The optical lens package  44  includes a focus lens group  60  and a zoom lens group  62 . It will be appreciated that the configuration of the lenses in the optical lens package  44  is not germane to the invention and that other lens configurations can be used. A lens group can have a single lens or a plurality of lenses. The optical lens package  44  also includes motors  64   a  and  64   b  for moving the one or more lenses in the lens groups  60  and  62  towards and away from each other to effect focusing and zooming. An image sensor, such as CCD image sensor  66 , is disposed behind the focus lens group  60  and captures subject light, which has passed through the external cameral lens  30  and is focused on a light-receiving surface of the CCD image sensor  66 . The CCD image sensor converts the light to an analog image signal that is outputted to an image-signal processing unit  68  via a flexible connection  69 . 
         [0055]    The optical lens package  44  is supported in the sleeve member  52  for axial movement along its longitudinal axis which, in the illustrated embodiment, is parallel with the direction of movement of the lenses of lens groups  60  and  62 . It will be appreciated, however, that in other configurations the direction of movement of the lenses may not be parallel with the longitudinal axis of the optical lens package. In such configurations, the optical lens package  44  preferably is supported for movement in the sleeve member  52  in a direction parallel to the direction of movement of the lenses. 
         [0056]    The sleeve member  52  is divided by the optical lens package  44  into two separate chambers  70  and  72 . The chambers  70  and  72  can be filled with any suitable fluid, such as air, for example. Other fluids such as certain oils (e.g., silicone oil) can also be used. Passageways  74   a  and  74   b  are provided in the cylindrical sidewall  54  creating a path for fluid to flow into and out of each chamber  70  and  72  as the optical lens package  44  is displaced. By way of example, if the optical lens package  44  is displaced to the left in  FIG. 3 , the volume of chamber  70  increases while the volume of chamber  72  decreases. This results in a drop in the air pressure in chamber  70  and, consequently, air is drawn into chamber  70  via passageway  74   a.  The displacement also causes an increase in the air pressure in chamber  72  and, consequently, air is forced out of passageway  74   b.  It will be appreciated that the size of the passageways  74   a  and  74   b  is such that flow of air into and out of the chambers  70  and  72  is restricted thereby producing a damping movement of the optical lens package  44 . As with each of the embodiments discussed herein, one may control the particular amount of damping by selecting appropriate sized passageways, etc., as will be appreciated. Preferably, sufficient damping movement is provided to avoid damage to the optical lens package  44  in the event the mobile phone  10  is dropped, but otherwise the optical lens package  44  remains generally fixed in position with normal use of the mobile phone  10 . 
         [0057]    Accordingly, in the illustrated embodiment, movement of the optical lens package  44  is damped by the increase in air pressure in the chamber on the side to which the optical lens package  44  shifts. It will be appreciated that the decreased pressure (e.g., suction) in the opposite chamber can also dampen movement of the optical lens package  44 . 
         [0058]    It will be appreciated that a resilient member, such as a spring (not shown), can be provided to return the optical lens package  44  to the neutral position illustrated in  FIG. 3 . The resilient member can be interposed between the optical lens package  44  and the end cap  56 , for example. 
         [0059]    Turning to  FIGS. 4 and 5 , another exemplary optical lens assembly  40  in accordance with an embodiment of the invention is illustrated. The optical lens assembly  40  of  FIG. 4  is similar in most aspects to the optical lens assembly of  FIG. 3  except that it is sealed and therefore does not have passageways  74   a  and  74   b.  Fluid flows between the chambers  70  and  72  via a connecting passageway, which in the illustrated embodiment is a channel  80  in the sleeve member  54 , as shown in  FIG. 5 . 
         [0060]    The channel  80  is sized to restrict flow of fluid between the chambers  70  and  72  so that movement of the optical lens package  44  is damped. Accordingly, the channel can be sized and/or shaped as a restricting orifice. Displacement of the optical lens package  44  to the left in  FIG. 4  will tend to decrease the volume of chamber  72  and increase the volume of chamber  70  thereby forcing fluid into chamber  70  via channel  80 . 
         [0061]    This embodiment is particularly well suited to the use of a liquid, such as silicone oil, as it is self-contained and does not vent to a fluid source (e.g. the atmosphere) outside the sleeve member  54 . As such, although not shown, the chambers  70  and  72  can be filled with a suitable damping liquid. It will be appreciated that other connecting passageways between the chambers  70  and  72  can be provided. For example, the optical lens package  44  can have one or more passageways connecting the chambers  70  and  72 . As another example, leakage at the interface of the sleeve member  54  and the optical lens package  44  can serve as the connecting passageway. 
         [0062]    It will be appreciated that the chambers  70  and  72  can be any suitable size. In addition, the chambers  70  and  72  can be filled or partially filled with resilient material, such as rubber or foam, for absorbing shock inputs. 
         [0063]    While in some applications air alone can provide adequate damping, each of the above-described exemplary embodiments can achieve additional damping by the application of a high viscosity grease or oil to the interface between the sleeve member  54  and the optical lens package  44 . Such high viscosity grease or oil, while providing lubrication to the interface, can have certain surface effects (e.g., stickiness) that tend to produce a drag that would oppose movement of the optical lens package  44 . Accordingly, in some applications the use of such grease or oil alone can be sufficient to provide suitable damping of the motion of the optical lens package  44 . 
         [0064]    The principles of shock dampening heretofore described can be applied to other types of lens configurations. For example, in  FIG. 6  an optical lens assembly  100  that can be mounted or supported in the housing of an electronic equipment, such as mobile phone  10 , is illustrated. The optical lens assembly  100  includes a barrel  102  fixed relative to the body of the mobile phone  10 , a fixed lens group  104 , a movable lens group  106 , and a piezoelectric element  108 . An image sensor package  110  includes a cover  112 , a holder  114 , and an image sensor  116  fixed relative to the body of the mobile phone  10 . A power supply  118  provides power to the image sensor package  110  and piezoelectric element  108 . 
         [0065]    The barrel  102  is hollow and cylinder-shaped and has a through hole  120  therein. A part of the inside wall of the barrel  102  defines an inner screw thread  122 . The other part of the inside wall of the barrel  102  is smooth. 
         [0066]    The fixed lens group  104  includes a fixed drawtube  124  and a first lens group  126 . The fixed drawtube  124  is hollow and cylinder-shaped. The outside wall of the fixed drawtube  124  has an outside screw thread  128  thereon. The first lens group  126  includes one or more lenses (not individually labeled) mounted in the fixed drawtube  124 . The fixed lens group  104  is assembled in the barrel  102 . The outside screw thread  128  threadingly mates with the inner screw thread  122  of the barrel  102 . 
         [0067]    The movable lens group  106  includes a movable drawtube  130  and a second lens group  132 . The movable drawtube  130  is hollow and cylinder-shaped. The second lens group  132  includes one or more lenses (not individually labeled) mounted in the movable drawtube  130 . The movable lens group  106  is slidably assembled in the barrel  102  and engages with the smooth part of the inside wall of the barrel  102 . The movable lens group  106 , as illustrated, partly protrudes out of the barrel  102 . In other embodiments to movable lens group  106  can be fully contained within the barrel  102 , as will be appreciated. 
         [0068]    The piezoelectric element  108 , which is fixed relative to the body of the mobile phone  10 , includes a substrate  160  and a piezoelectric portion  162 . The substrate  160  is hollow and cylinder-shaped. The piezoelectric portion  162  is arranged on the inside surface of the substrate  160 . The piezoelectric portion  162  can also or alternatively be positioned on the outside surface of the substrate  160 . The piezoelectric portion  162  can be made, e.g., of any of zinc oxide, lithium niobate, and lithium tantalate, or any other suitable piezoelectric material. One end of the movable lens group  106  is fixed to one end of the piezoelectric element  108 . The substrate  160  can be made of an elastic material, thereby facilitating changes in length of the piezoelectric portion  162  and providing mechanical support for the piezoelectric portion  162 . Accordingly, the movable lens group  106  is generally free to move axially within the barrel  102  in response to movement of the piezoelectric element  108 . 
         [0069]    The cover  112  is a piece of glass or another transparent solid material. The cover  112  is mounted on the holder  114  to prevent dust from falling in or otherwise reaching the interior of the holder  114 . 
         [0070]    The holder  114  is hollow and cylinder-shaped. The holder  114  includes a base plate  182  and a sidewall  184 . The base plate  182  and the sidewall  184  together establish a cavity  186 . Opposite to the base plate  182 , a sidestep  188  is defined in the holder  114 . The cover  112  is set on the sidestep  188  of the holder  114 . 
         [0071]    The image sensor  116  is mounted on the base plate  182  of the holder  114 . The image sensor  116  is electrically connected to a PCB (print circuit board) (not shown), thereby allowing the digital processing of the image data collected by the image sensor  116 . 
         [0072]    The power supply  118  supplies direct current to the piezoelectric element  108 , as well as the image sensor  116  and the PCB. The anode and the cathode are respectively connected to two different positions of the piezoelectric portion  162 . The piezoelectric portion  162  will variably deform, according to the voltage/current of the power supply  118 . 
         [0073]    When assembling the optical lens assembly  100 , the first lens group  124  and the second lens group  132  are respectively mounted in the fixed drawtube  124  and the movable drawtube  130  to form the fixed lens group  104  and the movable lens group  106 . Then, the fixed lens group  104  is inserted into the barrel  102 . The outside screw thread  128  of the fixed drawtube  124  mates with the inner screw thread  122  of the barrel  102 . The fixed lens group  104  is finally fixed in the barrel  102  by glue/adhesive, by fusion/brazing/soldering, and/or by a mechanical means. Inserted into the barrel  102 , the movable lens group  106  can slide relative to the barrel  102  along an axis of the barrel  102 . The cover  112 , the holder  114 , and the image sensor  116  are assembled into the image sensor package  110  beforehand. Meanwhile, the power supply  118  is connected to the piezoelectric portion  162  of the piezoelectric element  108 . Finally, the piezoelectric element  108  is assembled between the barrel  102  and the holder  114 . One end of the piezoelectric element  108  engages the movable lens group  106 , with one corresponding end of piezoelectric portion  62  being fixed to the movable lens group  106  and an opposite end of the piezoelectric element  108  being permanently attached to the holder  114  and the cover  112 . 
         [0074]    In accordance with an aspect of the invention, the optical lens assembly  100  also includes a passageway  190  for allowing fluid, such as air, to flow into and out of the barrel  102  in response to movement of the movable lens group  106 . As will be appreciated, a chamber  192  between the fixed lens group  104  and movable lens group  106  within the barrel  102  is generally sealed except for the passageway  190 . The passageway is sized, as previously described, to restrict the flow of fluid therethrough to thereby dampen movement of the movable lens group  106 . Instead of the passageway  190  or in addition thereto, one or more channels (not shown) can be provided in the barrel  102  and/or the movable drawtube  130  to allow fluid to flow from the chamber  192  in response to movement of the movable lens group  106 . For example, a channel such as channel  80  in the embodiment of  FIGS. 4 and 5  can be provided on the inner surface of the barrel  102  extending from the chamber  192  to the lower end of the barrel  102 . In an embodiment wherein the movable lens group  106  is fully contained within the barrel  102 , one or more channels can connect chambers separated by the movable lens group  106  for allowing fluid to flow therebetween in the manner illustrated in  FIGS. 4 and 5 , for example. 
         [0075]    It will now be appreciated that the present invention provides an optical lens assembly including a shock absorbing mount that tends to absorb shock inputs to thereby dampen movement of an optical lens package. Accordingly, the invention is particularly useful for electronic equipment such as mobile phones, PDA&#39;s, etc. with integrated cameras that are likely to be dropped and or mishandled resulting in severe shock inputs. The invention is applicable to a wide variety of lens packages and/or assemblies and/or other camera components. Although the illustrated embodiments describe motor and piezoelectric element actuated optical lens assemblies, it will be appreciated that the invention can be used with lens assemblies that are actuated by other mechanisms such as, for example, stepper motors, solenoids, etc. Further, it will be appreciated that other damping arrangements can be implemented using principles of the invention. For example, more than one lens group within a barrel can be configured for damping in accordance with the invention. 
         [0076]    It will further be appreciated that the rate of damping of the lens group is dependent in part upon the rate at which fluid flows into or out of the one or more chambers. It will be appreciated, therefore, that the desired damping generally is achieved by controlling this rate. In that regard, the chamber or chambers into and out of which fluid flows generally will be sealed except for the passageway that permits flow of fluid into and out of the chamber. Accordingly, controlling the rate of flow through the passageway in turn controls the rate of flow into and out of the chamber. Some leakage of fluid into and out of such chambers, however, can exist without departing from the scope of the invention. 
         [0077]    Specific embodiments of the invention have been disclosed herein. One of ordinary skill in the art will readily recognize that the invention may have other applications in other environments. In fact, many embodiments and implementations are possible. The following claims are in no way intended to limit the scope of the present invention to the specific embodiments described above. In addition, any recitation of “means for” is intended to evoke a means-plus-function reading of an element and a claim, whereas, any elements that do not specifically use the recitation “means for”, are not intended to be read as means-plus-function elements, even if the claim otherwise includes the word “means”. 
         [0078]    Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.