Abstract:
A camera includes a camera housing with a housing wall demarcating the interior of the camera housing, an optical aperture and a lenslet aperture extending through the housing wall, and an opaque blocking wall adjoined to and extending inwardly from the housing wall and circumscribing the lenslet aperture; a lenslet in the lenslet aperture aligned with an on-camera light source; a lens contained within the camera housing and aligned with the optical aperture to receive light entering the camera housing through the optical aperture; an imager within the camera housing and aligned with the lens to capture light passing through the lens; and circuitry contained within the camera housing communicative with the imager and operable to operate the camera. The circuitry includes a printed circuit board that abuts the opaque blocking wall and on which is mounted a light source positioned to be circumscribed by the opaque blocking wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/434729, filed Apr. 9, 2015, which is a National Stage of International Application No. PCT/US2015/010874, filed Jan. 9, 2015, which claims the benefit of U.S. Provisional Patent Application No. 61/926,214, filed Jan. 10, 2014, the disclosures of which are incorporated herein by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure is directed at a camera housing having walls for reducing internal reflections and a camera comprising the camera housing. 
       BACKGROUND 
       [0003]    Certain types of cameras include a light source for illuminating regions of interest that the cameras are to monitor. For example, some cameras are able to sense infrared (IR) and visible light and are correspondingly equipped with an on-camera IR and/or visible light sources for use in low-light conditions. In order for one of these cameras to properly monitor what is happening in a region of interest, the camera&#39;s image sensor should only detect light emanating from the region of interest as opposed to, for example, light from the on-camera IR or other light source that are reflected by internal components of the camera itself. 
       SUMMARY 
       [0004]    According to a first aspect, there is provided a camera, comprising a camera housing, which itself comprises (i) a housing wall demarcating the interior of the camera housing; (ii) an optical aperture and a lenslet aperture extending through the housing wall; and (iii) an opaque blocking wall adjoined to and extending inwardly from the housing wall and circumscribing the lenslet aperture; a lenslet in the lenslet aperture aligned with an on-camera light source; a lens contained within the camera housing and aligned with the optical aperture to receive light entering the camera housing through the optical aperture; an imager contained within the camera housing and aligned with the lens to capture light that has passed through the lens; and circuitry contained within the camera housing communicatively coupled with the imager and operable to operate the camera, the circuitry comprising a printed circuit board (PCB) that abuts against the opaque blocking wall and on which is mounted a light source positioned to be circumscribed by the opaque blocking wall. 
         [0005]    The lenslet aperture may comprise a first wide angle lenslet aperture, the lenslet may comprise a first wide angle lenslet, and the opaque blocking wall may comprise a first opaque wide angle lenslet blocking wall. The camera housing may further comprise a first narrow angle lenslet aperture; and a first opaque narrow angle lenslet blocking wall adjoined to and extending inwardly from the housing wall and circumscribing the first narrow angle lenslet aperture. The PCB may abut against the first opaque narrow angle lenslet blocking wall and have mounted on it the light source positioned to be circumscribed by the first opaque narrow angle lenslet blocking wall. The camera may further comprise a first narrow angle lenslet in the first narrow angle lenslet aperture. 
         [0006]    The opaque narrow and wide angle lenslet blocking walls may directly contact each other. 
         [0007]    The camera housing may further comprise a second wide angle lenslet aperture and a second narrow angle lenslet aperture; and a second opaque wide angle lenslet blocking wall and a second opaque narrow angle lenslet blocking wall, wherein the second opaque wide and narrow angle lenslet blocking walls may be adjoined to and extend inwardly from the housing wall and circumscribe the second wide angle and narrow angle lenslet apertures, respectively, and wherein the PCB may abut against the second opaque wide and narrow angle lenslet blocking walls and have mounted on it additional light sources positioned to be circumscribed by the second opaque wide and narrow angle lenslet blocking walls. The camera may further comprise a second wide angle lenslet and a second narrow angle lenslet in the second wide and narrow angle lenslet apertures, respectively. 
         [0008]    The first and second wide angle lenslet apertures may be on left and right sides of the optical aperture, respectively. 
         [0009]    The second opaque narrow and wide angle lenslet blocking walls may directly contact each other and not directly contact the first opaque narrow and wide angle lenslet blocking walls. 
         [0010]    The first and second wide angle lenslets may have centers separated by approximately 180°, and the centers of the first and second wide angle lenslets and a center of the optical aperture may be collinear. 
         [0011]    The first and second narrow angle lenslets may have centers above and offset approximately 45° from the centers of the first and second wide angle lenslets, respectively. 
         [0012]    The wide angle lenslets may be rectangular and the narrow angle lenslets may be circular. 
         [0013]    The camera may further comprise a threaded column for receiving a fastener for securing the PCB to the housing wall, and the threaded column may have a height identical to that of the opaque blocking wall and may be adjoined to and extend inwardly from the housing wall. 
         [0014]    The threaded column may directly contact the opaque blocking wall. 
         [0015]    The camera housing may be gaseously sealed to prevent air from outside the camera from entering the camera housing. 
         [0016]    The on-camera light source may include one or more of an infrared light source and a visible light source, or other light sources. 
         [0017]    According to another aspect, there is provided a main portion for containing a camera, a lens, and an imager, and a front portion of a camera housing, the front portion comprising: a face and sides extending from the face for joining to a remainder of a camera housing; an optical aperture and a lenslet aperture extending through the face; and an opaque blocking wall of uniform height adjoined to and extending from the face in a direction identical to that in which the sides extend, wherein the opaque blocking wall circumscribes the lenslet aperture. 
         [0018]    The lenslet aperture may comprise a first wide angle lenslet aperture, the opaque blocking wall may comprise a first opaque wide angle lenslet blocking wall, and the front portion may further comprise a first narrow angle lenslet aperture; and a first opaque narrow angle lenslet blocking wall adjoined to and extending inwardly from the face, circumscribing the first narrow angle lenslet aperture, and having a height identical to that of the first opaque wide angle lenslet blocking wall. 
         [0019]    The opaque narrow and wide angle lenslet blocking walls may directly contact each other. 
         [0020]    The front portion may further comprise a second wide angle lenslet aperture and a second narrow angle lenslet aperture; and a second opaque wide angle lenslet blocking wall and a second opaque narrow angle lenslet blocking wall, wherein the second opaque wide and narrow angle lenslet blocking walls may be adjoined to and extend inwardly from the face, respectively circumscribe the second wide angle and narrow angle lenslet apertures, and have a height identical to that of the first opaque wide angle lenslet blocking wall. 
         [0021]    The first and second wide angle lenslet apertures may be on left and right sides of the optical aperture, respectively. 
         [0022]    The second opaque narrow and wide angle lenslet blocking walls may directly contact each other and not directly contact the first opaque narrow and wide angle lenslet blocking walls. 
         [0023]    The first and second wide angle lenslets may have centers separated by approximately 180° and the centers of the first and second wide angle lenslets and a center of the optical aperture may be collinear. 
         [0024]    The first and second narrow angle lenslets may have centers above and offset approximately 45° from the centers of the first and second wide angle lenslets, respectively. 
         [0025]    The wide angle lenslets may rectangular and the narrow angle lenslets may be circular. 
         [0026]    The front portion may further comprise a threaded column for receiving a fastener for securing a printed circuit board (PCB) of the circuitry for operating the camera, the lens, and the aperture to the face, the threaded column may have a height identical to that of the opaque blocking wall and may be adjoined to and extend inwardly from the face. 
         [0027]    The threaded column may directly contact the opaque blocking wall. 
         [0028]    According to another aspect, there is provided a camera comprising a camera housing, comprising (i) a housing wall demarcating the interior of the camera housing; (ii) an optical aperture extending through the housing wall; (iii) a left wide angle lenslet aperture extending through the housing wall on a left side of the optical aperture and a right wide angle lenslet aperture extending through the housing wall on a right side of the optical aperture; (iv) a left narrow angle lenslet aperture extending through the housing wall on a left side of the optical aperture and a right narrow angle lenslet aperture extending through the housing wall on a right side of the optical aperture, the narrow angle lenslet apertures; and (v) left and right opaque blocking walls adjoined to and extending inwardly from the housing wall, the left opaque blocking wall circumscribing the left wide and narrow angle lenslet apertures and the right opaque blocking wall circumscribing the right wide and narrow angle lenslet apertures, wherein the left and right opaque blocking walls are of uniform height; a lenslet in each of the lenslet apertures, wherein each lenslet is aligned with an on-camera light source; a lens contained within the camera housing and aligned with the optical aperture to receive light entering the camera housing through the optical aperture; an imager contained within the camera housing and aligned with the lens to receive light that has passed through the lens; and circuitry contained within the camera housing communicatively coupled with the imager and operable to operate the camera, the circuitry comprising a printed circuit board (PCB) that abuts against the opaque blocking walls and on which is mounted four light sources, each of which is positioned to direct light through a different one of the lenslet apertures and be circumscribed by one of the opaque blocking walls. 
         [0029]    The on-camera light source may include one or more of an infrared light source and a visible light source, or other light sources. 
         [0030]    This summary does not necessarily describe the entire scope of all aspects. Other aspects, features, and advantages will be apparent to those of ordinary skill in the art upon review of the following description of specific embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    In the accompanying drawings, which illustrate one or more example embodiments: 
           [0032]      FIG. 1  is a perspective view of a camera assembly comprising a security camera and a mounting arm, according to one embodiment. 
           [0033]      FIG. 2  is a block diagram of an imaging apparatus that comprises part of the security camera. 
           [0034]      FIG. 3  is a perspective view of a front portion of a camera housing that comprises part of the security camera. 
           [0035]      FIG. 4  is a front elevation view of the front portion of the camera housing. 
           [0036]      FIG. 5  is a rear elevation view of the front portion of the camera housing showing a printed circuit board (PCB) attached to a rear side of the front portion. 
           [0037]      FIGS. 6A and 6B  are rear elevation views of the front portion of the camera housing with and without lenslets, respectively. 
           [0038]      FIG. 7  is a sectional view of the front portion of the camera housing, taken along line  7 - 7  in  FIG. 4 . 
           [0039]      FIG. 8A  is a sectional view of a prior art security camera taken along a midline of the camera and looking towards the left side of the camera, showing airflow within the camera. 
           [0040]      FIG. 8B  is a sectional view of the security camera of  FIG. 1  taken along a midline of the camera and looking towards the left side of the camera, showing airflow within the camera. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    Directional terms such as “top”, “bottom”, “upwards”, “downwards”, “vertically”, and “laterally” are used in the following description for the purpose of providing relative reference only, and are not intended to suggest any limitations on how any article is to be positioned during use, or to be mounted in an assembly or relative to an environment. Additionally, the term “couple” and variants of it such as “coupled”, “couples”, and “coupling” as used in this description are intended to include indirect and direct connections unless otherwise indicated. For example, if a first device is coupled to a second device, that coupling may be through a direct connection or through an indirect connection via other devices and connections. Similarly, if the first device is communicatively coupled to the second device, communication may be through a direct connection or through an indirect connection via other devices and connections. 
         [0042]    One example type of camera that comprises an on-board light source is a camera that is able to illuminate a region of interest using infrared (IR) light and that is able to record and display the IR light that the region of interest reflects. This permits the camera to record images in darkness. A design goal for this type of camera is that the IR light the camera emits and that is reflected back to the camera&#39;s imager should be reflected only by the region of interest and not by internal components of the camera itself (reflections off of these internal components are “internal reflections”). Internal reflections can interfere with the camera&#39;s ability to identify activity specific to the region of interest. One way the problem of internal reflections is addressed in a conventional camera is by optically isolating the camera&#39;s optical aperture, lens, and imager from the on-camera IR light source using a lens chamber. Unfortunately, doing this requires a more complicated and expensive housing and can inhibit airflow across the camera&#39;s optical aperture, which promotes condensation in environmental cameras that can be detrimental to image quality. 
         [0043]    The same design may also be used with visible light sources or other forms of light sources and light sources may be combined. For example, the primary illumination light source may be IR, while visible on-camera light sources are also utilized, either for object illumination or for other purposes, such as identifying the existence of the camera to observers, providing an indication that the camera is on or recording, or other security purposes. While a visible light source may be used in place of or in conjunction with the IR light sources referenced herein, the remainder of the present disclosure will only refer to IR light sources so as to simplify the present disclosure, with the understanding that the term “IR” may equally refer to visible light or other light sources, alone or in combination with IR. 
         [0044]    The embodiments described herein use opaque blocking walls that surround the on-camera light source as opposed to a lens chamber that optically isolates the optical aperture, lens, and imager from the on-camera light source. The opaque blocking walls permit the camera to be designed without a lens chamber, which reduces components and facilitates air flow across the optical aperture and reduces condensation. While in the following example embodiments no fan is used, in alternative embodiments (not depicted) a fan may be used to blow air across the camera and the optical aperture to further reduce condensation, whereas in a camera that comprises a lens chamber this could not be easily done. 
         [0045]    Referring now to  FIG. 1 , there is shown a camera assembly  100  according to a first embodiment. The camera assembly  100  comprises a security camera  101  movably coupled to a mounting arm  103 , which is mountable to a mounting surface such as a ceiling or wall (not shown). The camera assembly  100  also comprises a sun shroud  105  slidably coupled to the top of the camera  101 . Additionally, while the camera  101  in  FIG. 1  is a bullet camera, alternative embodiments (not depicted) may comprise a different type of camera, such as a dome camera. 
         [0046]    The camera  101  itself comprises a camera housing  104  comprising a housing wall that demarcates the interior of the camera  101  from the camera&#39;s  101  environment. A front portion  107  of the camera housing  104  comprises, at its front, a substantially flat face  301  (shown in  FIGS. 3 and 4 ). At the center of the face  301  is an optical aperture  106  through which light from the environment enters the camera  101 . Around the optical aperture  106  and overlaid on the face  301  is a tinted window  102  that hides the on-camera light source, as discussed in more detail below. 
         [0047]    Referring now to  FIG. 2 , there is shown a block diagram of an imaging apparatus  200  that also comprises part of the camera  101 . The imaging apparatus  200  comprises a system on a chip  202  (hereinafter “SoC  202 ”), which includes a processor  204  that is communicatively coupled to each of the SoC&#39;s  202  other components: an image signal processor  210 , a media access controller  212 , general purpose input/output (GPIO) lines  206 , and an I 2 C interface  208 . The processor  204  is also communicatively coupled to memory  205  that is external to the SoC  202 . Encoded on to the memory  205  is program code that the processor  204  can execute to operate the camera  101 . 
         [0048]    The imaging apparatus  200  also comprises a lens driver  216  communicatively coupled to the I 2 C interface  208 , a zoom lens  220  mechanically coupled to the lens driver  216 , an imager  218  communicatively coupled to the image signal processor  210 , and a pair of current drivers  222   a,b  (collectively, “current drivers  222 ”) each electrically coupled to a different one of the GPIO lines  206 . Each of a pair of IR emitters  228   a,b  (collectively, “IR emitters  228 ”) is electrically coupled to a different one of the current drivers  222  and emits IR light when driven by the current drivers  222 . One of the IR emitters  228  produces an IR beam having a wide angle linear profile (hereinafter “wide angle emitter  228   a ”) while the other of the IR emitters  228  produces an IR beam having a narrow angle linear profile (hereinafter “narrow angle emitter  228   b ”). The imager  218  is configured to capture light in the infrared spectrum and can be, for example, a digital sensor such as a complementary metal-oxide-semiconductor (CMOS) sensor. The specifications of the imager  218  and the zoom lens  220  can be selected based on an operator&#39;s requirements and performance expectations. 
         [0049]    While  FIG. 2  shows an embodiment with only a pair of the IR emitters  228 , other embodiments (not depicted) can feature more than two of the IR emitters  228 , any one or more of them producing an IR beam of a different linear profile, and which can be combined to produce an IR beam with a variable linear profile. 
         [0050]    Each of the IR emitters  228  in this embodiment respectively comprises a set of infrared emitting diodes (IREDs)  224 , each of which acts as an on-camera IR light source. An example of these IREDs  224  are a pair of Osram™ SFH4715S IREDs. The wide angle emitter  228   a  further comprises a right wide angle lenslet  230   a  and a left wide angle lenslet  230   b  (collectively, “wide angle lenslets”  230 ) and the narrow angle emitter  228   b  analogously further comprises a right narrow angle lenslet  231   a  and a left narrow angle lenslet  231   b  (collectively, “narrow angle lenslets”  231 ). The wide angle lenslets  230  are configured to shape the IRED emission into an IR beam with a linear profile that is relatively widely dispersed, and the narrow angle lenslets  231  are configured to shape the IRED emission into an IR beam with a linear profile that is relatively narrowly dispersed. Examples of these lenslets  230 , 231  are those provided by Ledil Oy™ based in Finland. 
         [0051]    The current drivers  222  are designed to regulate the current delivered to the IR emitters  228 . The current drivers  222  can be controlled to deliver all available power to one or the other of the IR emitters  228 , or to vary the power ratio between the two IR emitters  228 . The current drivers  222  may each be, for example, the AL8805 Buck LED Driver by On Semiconductor™. This program code stored on the memory  205  includes instructions for sending a control signal from the SoC along two of the GPIO lines  206  to the current drivers  222  to produce the IR beam. 
         [0052]      FIGS. 3 and 4  respectively depict perspective and front elevation views of the front portion  107  of the camera housing  104  with the tinted window  102  removed, revealing the front portion&#39;s  107  face  301 . Extending rearwardly from the front portion&#39;s  107  rear edge is a lip  306  that fits within a corresponding groove in the front edge of the remainder of the camera housing  104  (not shown). The optical aperture  106  is in the middle of the face  301  and its center is located along the front portion&#39;s  107  longitudinal axis. The left and right wide angle lenslets  230   a,b  extend through the face  301  on the optical aperture&#39;s  106  left and right sides, respectively, with the optical aperture&#39;s  106  center and the centers of the wide angle lenslets  230  being collinear. The narrow angle lenslets  231   a,b  are circular and respectively extend through the face  301  above the wide angle lenslets  230   a,b . Relative to the center of the optical aperture  106 , the centers of the left wide and narrow angle lenslets  230   a , 231   a  and of the right wide and narrow angle lenslets  230   b , 231   b  are respectively offset by approximately 45°. 
         [0053]    Attached to a rear side of the front portion  107  is a PCB  502 , which is visible in the rear elevation view of  FIG. 5  and on which the current drivers  222 , IR emitters  228 , IREDs  224 , and lenslets  230 , 231  are mounted. The lenslets  230 , 231  are mounted to the PCB  502  on top of the IREDs  224 . The SoC  202 , memory  205 , lens driver, and imager are mounted on other PCBs (not shown) located elsewhere in the camera housing  104 . As discussed in further detail below, the PCB  502  is mounted to the front portion  107  so that it is parallel with the face  301 . While in the present embodiment the lenslets  230 , 231  are directly connected to the PCB  502 , in alternative embodiments (not depicted) the lenslets  230 , 231  may be mounted, for example, directly to the housing  104  and be only indirectly connected to the PCB  502 . 
         [0054]      FIG. 6A  is a rear elevation view of the front portion  107  and the lenslets  230 , 231 . Visible in  FIG. 6  on the rear side of the front portion  107  are left and right IR blocking walls  602   a,b  (collectively , “blocking walls”  602 ).  FIG. 6B  is a rear elevation view of the front portion  107  in isolation (i.e. with the lenslets  230 , 231  removed) to reveal left and right wide angle lenslet apertures  606   a,b  and left and right narrow angle lenslet apertures  608   a,b  through which the lenslets  230   a,b  and  23   a,b , respectfully, extend when they are in place. 
         [0055]    The right blocking wall  602   b  comprises a rectangular portion that circumscribes the right wide angle lenslet aperture  606   b  (and, in  FIG. 6A , the right wide angle lenslet  230   b ) and a circular portion that circumscribes the right narrow angle lenslet aperture  608   b  (and, in  FIG. 6A , the left wide angle lenslet  230   a ) (the rectangular portion is the “right wide angle lenslet blocking wall” and the circular portion is the “right narrow angle lenslet blocking wall”). The right wide angle and narrow angle lenslet blocking walls merge and directly contact each other in an area between the right lenslet apertures  606   b , 608   b.  The left blocking wall  602   a  comprises a rectangular portion that circumscribes the left wide angle lenslet aperture  606   a  (and, in  FIG. 6A , the left wide angle lenslet  230   a ) and a circular portion that circumscribes the left narrow angle lenslet aperture  608   a  (and, in  FIG. 6A , the left narrow angle lenslet  231   a ) (the rectangular portion is the “left wide angle lenslet blocking wall” and the circular portion is the “left narrow angle lenslet blocking wall”). The left wide angle and narrow angle lenslet blocking walls merge and directly contact each other in an area between the left wide and narrow angle lenslet apertures  606   a , 608   a.  The blocking walls  602  are made of an opaque material, which in the depicted embodiment is aluminum, but which in other embodiments may be another opaque material such as an opaque plastic or steel. In the depicted embodiment the blocking walls  602  extend to meet the PCB&#39;s  502  surface when the PCB  502  is mounted to the front portion  107 . To prevent light leakage, the blocking walls  602  and the rear side of the face  301  abut against each other. For example, the blocking walls  602  and the face  301  in the depicted embodiment are made from a single piece of die-cast metal. In alternative embodiments (not depicted), the blocking walls  602  and the face  301  may be formed from separate pieces of metal but be welded together along the blocking walls&#39;  602  edges, the blocking walls  602  and face  301  may be adhered together, or the blocking walls  602  and face  301  may be pressed together and held in place using screws or other fasteners. Regardless, the intersection between the blocking walls  602  and the face  301  is optically non-transmissive to prevent light from the IREDs  224  from escaping from between them. 
         [0056]    Also extending from the rear of the face  301  are four threaded columns  604 , each with a height identical to that of the blocking walls  602  and having an interior threaded to receive one of four fasteners in the form of screws  504  used to secure the PCB  502  to the face  301 . To mount the PCB  502  to the face  301 , the PCB  502  is positioned so that screw holes extending through the PCB  502  are aligned with the threaded columns  604  and the PCB  502  is then screwed to the face  301 . As the columns  604  are the same height as the blocking walls  604 , screwing the PCB  502  tightly against the columns  604  also, ideally, eliminates any gaps between the PCB  502  and the blocking walls  604 . 
         [0057]    The intersection between the blocking walls  602  and the PCB  502  is illustrated in  FIG. 7 , which is a cross-section taken along line  7 - 7  of  FIG. 4 .  FIG. 7  shows the wide and narrow angle lenslets  230   b , 231   b  and the portions of the blocking wall  602   b  that circumscribe these lenslets  230   b , 231   b  as the shaded areas above and below the these lenslets  230   b , 231   b . The PCB  502  is screwed against the columns  604  and accordingly abuts against the blocking walls  602 , which prevents light from escaping between the blocking walls  602  and the PCB  502 . In alternative embodiments (not depicted), the exposed edges of the blocking walls  602  are covered in a compressible material such as a soft rubber to compensate for any irregularities in the shape of the walls  602  so that the walls  602  and the PCB  502  may remain optically sealed. As light from the IREDs  224  cannot pass through the blocking walls  602  nor, ideally, escape between the blocking walls  602  and either the face  301  or the PCB  502 , internal reflections are mitigated. 
         [0058]    Without the need to shield the imager  218  from internal reflections, the camera  101  can be manufactured without a lens chamber.  FIG. 8A  shows a sectional view of a prior art camera taken along a midline and looking towards the left side of that prior art camera, showing airflow within the camera, such as past the zoom lens  220 . A portion of the lens chamber L that is present to prevent internal reflections from interfering with image acquisition is shown blocking airflow within the camera, which is represented by the arrows.  FIG. 8B  shows an analogous, simplified sectional view of the camera  101  without the lens chamber L, which use of the blocking walls  602  (previously shown) permit. Air is able to flow in the area formerly occupied by the lens chamber L near the optical aperture  106 , thus inhibiting condensation. In another embodiment (not shown), the camera  101  also comprises a fan to further promote circulation. 
         [0059]    The camera  101  shown in  FIG. 8B  permits air from the camera&#39;s  101  environment to enter the camera  101 . In an alternative embodiment (not depicted), the camera housing  104  may be gaseously sealed to prevent air from the environment from entering the camera  101 , which can help prevent condensation that would otherwise result from humid environmental air entering the camera&#39;s  101  interior. In embodiments in which the camera  101  is sealed, a fan may or may not be present within the camera to promote air circulation. 
         [0060]    It is contemplated that any part of any aspect or embodiment discussed in this specification can be implemented or combined with any part of any other aspect or embodiment discussed in this specification. 
         [0061]    While particular embodiments have been described in the foregoing, it is to be understood that other embodiments are possible and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to the foregoing embodiments, not shown, are possible.