Patent Publication Number: US-2007101372-A1

Title: Headrest mounted entertainment system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      The application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/732,788, filed Nov. 2, 2005, titled HEADREST ENTERTAINMENT SYSTEM, U.S. Provisional Application No. 60/740,540, filed Nov. 29, 2005, titled HEADREST ENTERTAINMENT SYSTEM, and U.S. Provisional Application No. 60/811,879, filed Jun. 6, 2006, titled HEADREST MOUNTED ENTERTAINMENT SYSTEM, the entire contents of each of which are hereby incorporated by reference herein and made a part of this specification 
    
    
     BACKGROUND OF THE INVENTION  
     Field of the Invention  
      This application relates to entertainment systems that can be mounted in a vehicle, such as an automobile, and more particularly relates to headrest-mounted entertainment systems for vehicles.  
     SUMMARY OF THE INVENTION  
      In one embodiment, a mobile media system is provided that comprises an entertainment system having a first cable coupled with a first plug. The first plug comprises a first interference surface. The mobile media system further comprises a second cable coupled with a second plug. The second plug comprises a second interference surface, and the first and second plugs are configured to couple with each other. The mobile media system further comprises a retention device that includes a body at least partially defining a cavity configured to accept the first and second plugs. The retention device further comprises a third interference surface configured to cooperate with the first interference surface to substantially prevent movement of the first plug relative to the second plug. The retention device further comprises a fourth interference surface configured to cooperate with the second interference surface to substantially prevent movement of the second plug relative to the first plug.  
      In another embodiment, a media system is provided that comprises an entertainment system configured to be mounted in a headrest of a vehicle. The entertainment system has a first cable coupled with a first connector. The media system further comprises a second cable coupled with a second connector, and the first and second connectors are configured to couple with each other. The media system further comprises a retainer configured to couple with the first and second connectors. The retainer substantially inhibits axial movement between the first and second connectors when coupled therewith.  
      In another embodiment a media system is provided that comprises an entertainment system configured to be mounted in a headrest of a vehicle. The entertainment system has a first cable coupled with a first connector. The media system further comprises a second cable coupled with a second connector, and the first and second connectors are configured to couple with each other. The media system further comprises a retainer configured to couple with the first and second connectors. The retainer substantially inhibits transverse movement between the first and second connectors when coupled therewith.  
      In another embodiment, a media system is provided that comprises an entertainment system configured to be mounted in a headrest of a vehicle. The entertainment system comprises a first cable coupled with a first connector. The media system further comprises a second cable coupled with a second connector, and the first and second connectors configured to couple with each other. The media system further comprises a retainer comprising a first interference surface and a second interference surface. The first and second interference surfaces are configured to substantially prevent axial movement of the first and second connectors relative to each other. The retainer further comprises at least a third interference surface configured to substantially prevent radial movement of the first and second connectors relative to each other. The retainer further comprises a fastener configured to permit the retainer to selectively couple with and decouple from the first and second connectors  
      In another embodiment, a mobile video system is provided. The system includes a motorized land vehicle and an entertainment system. The motorized land vehicle includes a passenger compartment and a seat that has a headrest. The seat is positioned in the passenger compartment. The entertainment system includes a component mounting frame that is configured to be positioned in the headrest, a signal source, a video monitor, and a cover. The signal source has an access aperture through which a non-volatile storage medium can be inserted. The signal source is capable of generating a signal based on data stored in the non-volatile storage medium. The signal source is coupled with the component mounting frame such that when the component mounting frame is positioned in the headrest, the access aperture is located adjacent an upper surface of the headrest. The video monitor is configured to reproduce at least a portion of the signal. The cover is pivotably mounted to the component mounting frame and has a first position in which the access aperture is exposed such that the non-volatile storage medium can be inserted therethrough and a second position in which the access aperture is blocked.  
      In another embodiment, a headrest entertainment assembly is provided that comprises a headrest and an entertainment system. The headrest has an upper surface, a lower surface, and a cavity. The entertainment system includes a component mounting frame, a signal source, a monitor, and a cover. The component mounting frame is configured to be positioned within the cavity of the headrest. The signal source has an access aperture through which a non-volatile storage medium can be inserted. The signal source is capable of generating a signal based on data stored in the non-volatile storage medium. The signal source is coupled with the component mounting frame such that the access aperture is adjacent the upper surface of the headrest when the component mounting frame is positioned in the cavity. The monitor is coupled with the component mounting frame and is configured to reproduce at least a portion of the signal. The cover is coupled with the mounting frame and has a first position in which the access aperture is exposed such that the non-volatile storage medium can be inserted through the access aperture and a second position in which the access aperture is blocked.  
      In another embodiment, a headrest entertainment system is provided that includes a frame, a DVD player, a monitor, and a cover. The frame is configured to be positioned within a vehicle headrest. The DVD player has a slot through which a digital video disc (“DVD”) can be inserted. The DVD player is coupled with the frame such that the slot is adjacent an upper surface of the headrest when the frame is positioned within the headrest. The monitor is coupled with the frame and configured to reproduce at least a video portion of the DVD. The cover has a first position in which the access aperture is exposed such that the DVD can be inserted through the slot and a second position in which the slot is blocked.  
      In another embodiment, a headrest entertainment system is provided that comprises a frame configured to be positioned within a vehicle headrest. The entertainment system further comprises a source coupled with the frame and configured to generate a signal to be reproduced within a vehicle. The signal includes a radio portion. The entertainment system further comprises a monitor coupled with the frame and configured to reproduce at least the video portion of the signal. The entertainment system further comprises a first aperture positioned on a first surface of the headrest and a second aperture positioned on a second surface of the headrest opposite the first surface. The entertainment system further comprises a fan coupled with the frame and positioned adjacent to at least one of the apertures.  
      In another embodiment, a headrest entertainment system is provided that comprises a vehicle headrest, a frame, a DVD player, a monitor, and a heat management system. The vehicle headrest has a cavity formed therein. The frame is configured to be positioned within the cavity of the vehicle headrest. The DVD player has a slot through which a digital video disc (“DVD”) can be inserted. The monitor is coupled with the frame and is configured to reproduce at least a video portion of a signal from the DVD. The heat management system includes a plurality of venting structures and a fan. The venting structures are formed adjacent to an external surface of the headrest. The fan is coupled with the frame and positioned adjacent to at least one of the venting structures.  
      In another embodiment, a mobile video system is provided that comprises a first entertainment system mountable in a first headrest of a vehicle. The first entertainment system comprises a first input having a structure and a first output having a structure. The mobile video system further comprises a second entertainment system mountable in a second headrest of a vehicle. The second entertainment system comprises a second input and a second output. The second input has a structure the same as the structure of the first input and the second output has a structure the same as the structure of the first output. The mobile video system further comprises an adapter configured to couple the first input with the second output and the second input with the first output.  
      In another embodiment, a media system is provided that comprises a first headrest-mountable entertainment system. The first headrest-mountable entertainment system comprises a first connector comprising a first input and a first output. The media system further comprises a second headrest-mountable entertainment system. The second headrest-mountable entertainment system comprises a second connector comprising a second input and a second output. The media system further comprises an adapter. The adapter comprises a third connector configured to couple with either the first or second connector and a fourth connector configured to couple with either the first or second connector. The adapter further comprises a first communication line coupled with the third and fourth connectors such that the first output is able to communicate with the second input or the second output is able to communicate with the first input. The adapter further comprises a second communication line coupled with the third and fourth connectors such that the first output is able to communicate with the second input or the second output is able to communicate with the first input. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other features, aspects and advantages of the present invention will be better understood with reference to preferred embodiments which are illustrated in the accompanying drawings. The illustrated embodiments are not intended to define the outer limits of the scope of the present invention.  
       FIG. 1  is a top perspective view of one embodiment of a headrest entertainment assembly that includes an entertainment system mounted in a headrest of a vehicle. Access to at least one component of the entertainment system can be limited by a cover, which is shown in a closed position.  
       FIG. 1A  is similar to  FIG. 1  showing another embodiment of a headrest entertainment assembly.  
       FIG. 2  is a top perspective view of the headrest entertainment assembly of  FIG. 1  showing the cover in an open position and showing a monitor of the entertainment system in a tilted position.  
       FIG. 3  is a top view of the headrest entertainment system of  FIG. 1  with the cover in an open position and the monitor in a tilted position.  
       FIG. 4  is a front plan view of the headrest entertainment system of  FIG. 1 .  
       FIG. 5  is a front perspective exploded view of the headrest entertainment assembly of  FIG. 1  with the entertainment system removed from the headrest.  
       FIG. 6  is a rear perspective exploded view of the entertainment system of  FIG. 1  with a monitor assembly removed therefrom.  
       FIG. 7  is a rear plan view of one embodiment of an entertainment system.  
       FIG. 7A  is an enlarged view of a portion of the entertainment system of  FIG. 7 .  
       FIG. 8  is a rear perspective exploded view of the entertainment system of  FIG. 7  with a portion of a cooling system shown removed therefrom.  
       FIG. 8A  is an enlarged view of a portion of  FIG. 8  showing the removed portion of a cooling system in greater detail.  
       FIG. 9  is a rear perspective exploded view of the entertainment system of  FIG. 7  showing a signal source removed therefrom.  
       FIG. 10  is a front perspective exploded view of the entertainment system of  FIG. 7  showing portion of a monitor assembly in a tilted position.  
       FIG. 11  is a perspective view of one embodiment of a portion of a mounting system.  
       FIG. 12  is a front perspective exploded view of one embodiment of a headrest entertainment system with one embodiment of a component mounting frame shown removed therefrom.  
       FIG. 13  is a perspective exploded view of one embodiment of a headrest with a portion of one embodiment of a mounting system shown removed therefrom.  
       FIG. 14  is a perspective view of one embodiment of a portion of a mounting system.  
       FIG. 15  is a plan view of one embodiment of a cooling fan.  
       FIG. 16  is a schematic illustration of one embodiment of a mobile video system having an adapter coupled with a first and second entertainment system.  
       FIG. 16A  is a front plan view of one embodiment of an adapter for coupling with a first and second entertainment system.  
       FIG. 16B  is a partial top plan view of the adapter of  FIG. 16A  showing coupler interfaces of two connectors.  
       FIG. 17  is a schematic illustration of one embodiment of an entertainment system.  
       FIG. 18  is a top plan view of one embodiment of an entertainment system connector and one embodiment of an adapter connector.  
       FIG. 19  is a front plan view of one embodiment of an entertainment system connector coupled with an adapter connector.  
       FIG. 20  is a schematic illustration of one embodiment of an adapter coupled with a power source.  
       FIG. 20A  is a partial perspective view of one embodiment of a noise suppressor coupled with electrical lines of an adapter.  
       FIG. 21  is a front perspective view of one embodiment of a retention device in a closed configuration and enclosing two coupled connectors.  
       FIG. 22  is a front perspective view of one embodiment of a retention device in an open configuration.  
       FIG. 23A  is a side elevation view of one embodiment of a retention device in a closed configuration.  
       FIG. 23B  is a side elevation view of another embodiment of a retention device in a closed configuration.  
       FIG. 24  is a top plan view of one embodiment of a retention device alongside two coupled connectors. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       FIG. 1  shows one embodiment of a headrest entertainment assembly  10 . The assembly  10  has a number of advantageous features. As discussed further below, the headrest entertainment assembly  10  and some variations thereof include a component cover that provides protection in connection with a signal source. Another feature of the assembly  10  and of some variations is a cooling system that keeps the components thereof from overheating. Further advantages of the assembly  10  and of some variations thereof reside in various inventive techniques for manufacturing the assembly  10 , which techniques provide advantages associated with inventory control. Also, some embodiments of the assembly  10  and techniques for producing the assembly result in enhanced safety features for passengers in a vehicle in which the assembly  10  is mounted.  
      The headrest entertainment assembly  10  includes a vehicle headrest  14  and an entertainment system  18 . Preferably the headrest entertainment assembly  10  is mounted in a vehicle, such as a car. As used herein “car” is a broad term and is used in its ordinary sense and refers, without limitation, to any personal land transportation vehicle, e.g., a passenger automobile, a truck, a van, a minivan, a sport-utility vehicle, and similar such vehicles. Certain features, aspects and advantages of the embodiments described herein can be used with other vehicles.  
      The headrest entertainment assembly  10  can be constructed by various preferred methods, which are discussed below. Broadly, in one method, the headrest  14  is formed about other portions of the headrest entertainment assembly  10  so as to provide an integral unit. In other methods, interchangeability of components is enhanced by making the headrest  14  separable from other components of the headrest entertainment assembly  10 .  
      Features of the vehicle headrest  14  are discussed below in connection with various embodiments. In one variation discussed below, the headrest  14  forms a portion of a seat of a vehicle and can be separately movable or adjustable relative to other portions of the seat. Although the headrest environment is preferred, in other embodiments entertainment systems comprising a sub-combination of the components of the assembly  10  can be deployed in an upper region of a seat, e.g., a seat back. The headrest  14  can take other suitable forms.  
      The headrest entertainment assembly  10  also includes a mounting system  22 . In one variation, the mounting system  22  includes at least one seat post  26  that extends between the headrest  14  and a seat back (not shown) to which the headrest  14  can be coupled. In the illustrated embodiment, the mounting system  22  includes two seat posts  26 . The seat posts  26  can be solid or hollow and can be configured to convey signals from or to the headrest entertainment assembly  10 . Preferably, where two or more seat posts  26  are provided at least one of the seat posts is hollow, having a passage extending therethrough in which at least a portion of a cable conveying the signal can be located. As discussed further below, in some embodiments the size of the passage can be enlarged by reducing the thickness of a wall of the seat posts  26 . As discussed further below, in some embodiments, the headrest entertainment assembly  10  includes a signal source mounted in the headrest  14 . In other embodiments, a signal source is not mounted in the headrest  14 , but is located elsewhere within the vehicle. In other embodiments, the headrest entertainment assembly  10  includes multiple signal sources, one or more of which can be mounted in the headrest and one or more of which can be located elsewhere in the vehicle. In other embodiments, multiple entertainment systems can be provided in multiple headrests. In other embodiments, multiple entertainment systems and multiple signal sources can be provided such as is described in U.S. Pat. No. 6,871,356, which is hereby expressly incorporated by reference herein.  
      The seat post  26  arrangement facilitates adjustability of the headrest entertainment assembly  10 . This adjustability can be combined with additional modes of adjustability, such as tilting of a monitor or other portion of the headrest entertainment assembly  10 , as discussed further below.  
      As discussed further below, the construction of the mounting system  22 , e.g., of the posts  26 , may be such that cables that interconnect a plurality of entertainment systems can be quickly and efficiently routed therethrough. As discussed further below, one way to facilitate quick routing of a signal cable through the post  26  is by increasing the inner cross-sectional size (e.g., diameter) of a hollow passage extending through the post  26 . As discussed further below, the inner cross-sectional size of a passage extending through the posts  26  can be increased by increasing the size (e.g., the inner and outer diameter) of the posts  26 . In some applications, the outer size of the posts  26  can not be increased because the size of a corresponding post hole in the seat back in which the post  26  is inserted is selected by car or seat manufacture and cannot easily be increased. In some situations, such as when the outer size of the posts  26  cannot easily be increased, the mounting system  22  can be configured to permit the wall thickness of the posts  26  to be decreased. By providing a fixed outer size and by reducing the thickness of the wall of the post  26 , the inner size of the passage in the post can be increased, making routing of signal cables easier. In some arrangements discussed further below, the mounting system  22  is configured to permit the wall thickness of the posts  26  to be decreased by providing a reinforced member that extends between two posts  26 . The mounting system  22  is discussed in more detail in connection with  FIG. 11 .  
      In one embodiment, the headrest  14  includes a forward-facing side  28  that includes a pad or a pillow  30  to cushion the head of an occupant in the seat with which the headrest is coupled. The pillow  30  may extend to any of a top, bottom, side-facing side  33 , and rear-facing side  32  of the headrest  14 , as shown in  FIG. 13 . Preferably, the pillow  30  is formed by blow-molding a foam material into a mold having a shape and design appropriate for the car in which the headrest  14  is to be used. For example, the headrest  14  can have the same outer shape and design as the factory headrest. The pad  30  can then be wrapped in a suitable material, such as a fabric, e.g., solid or perforated leather, or other suitable material. As discussed further below, in one technique, the pad  30  is blow molded directly onto a portion of the mounting system  22  such that the pad  30  and the mounting system  22  are integrally connected. In another technique, a pad  30  is blow molded as a separate component and is configured to receive at least a portion of the mounting system  22  during assembly such that the pad  30  and the mounting assembly  22  could be disassembled after shipment from the factory.  
      As discussed above, the pillow  30  provides cushioning for a person seated in the seat with which the headrest  14  is coupled, e.g., to minimize injury in the event of an accident. The headrest  14  preferably also includes a rear-facing side  32 . Preferably an entertainment system mounting cavity  34  is formed in the headrest  14 . In some embodiments, the entertainment system mounting cavity  34  is accessible from the rear-facing side  32 .  
      Access can be provided to the entertainment system mounting cavity  34  through a mounting cavity aperture  36 . Preferably the mounting cavity aperture  36  is shaped to receive the entertainment system  18 . In one embodiment, the aperture  36  is at least partially surrounded by a plurality of edges on the rear-facing side  32  of the headrest  14 . The aperture  36  can also be partly surrounded by at least one edge on a top surface  37  of the headrest  14 . In some arrangements, the headrest  14  includes an intermediate surface that extends between the top surface  37  and the rear-facing surface  32 . The intermediate surface can be curved or flat, e.g., radiused or beveled. Accordingly, the mounting cavity aperture  36  can be at least partly surrounded by one or more edges that extend between the top surface  37  and the rear-facing surface  32  of the headrest  14 . In other embodiments, the mounting cavity aperture.  36  can be at least partially surrounded by one or more edges located on a bottom surface of the headrest  14 .  
      As discussed below, in some embodiments, the entertainment system  18  is configured to be able to move when positioned in the mounting cavity aperture  36 . For example, in some embodiments, the entertainment system can pivot at least partially into and out of the entertainment system mounting cavity  34  through the mounting cavity aperture  36 .  
      In some embodiments, the headrest entertainment assembly  10  includes a cooling system to maintain the operating temperature of the components of the headrest entertainment assembly  10  in an acceptable range. Further details of the cooling system are discussed below. In one embodiment, the headrest  14  includes an opening or aperture  38  adjacent which at least a portion of the cooling system can be mounted. The aperture  38  is one configuration of a venting structure that can be incorporated to enhance cooling of the headrest entertainment assembly  10 . In some embodiments, at least one of a plurality of apertures  38  and other venting structures adjacent an external surface of the assembly  10  can be provided to enhance cooling. For example, as discussed below, a first aperture  38  can be provided on one surface and a second aperture  38  can be provided on a second surface that is opposite the first surface. This arrangement advantageously increases cross-flow from the first aperture to the second aperture. Cooling of the components of the headrest entertainment assembly  10  can be further enhanced by additional venting structures and by devices, e.g., one or more fans  40 , which increase flow across the components thereof. Features of various embodiments of cooling systems will be discussed in greater detail below.  
       FIG. 13  shows that in some embodiments, a plurality of openings  38  are provided for enhanced cooling of the entertainment system  18 . Also, although the openings  38  are located on side surfaces of the headrest  14 , these components can be located on other surfaces, such as on one or more of a top surface, a front surface, a rear surface, and a bottom surface. The side surfaces are advantageous locations for the openings  38  because they are exposed in all positions of the headrest  14  and are spaced from the entertainment system  18  and the surface facing the head of the person in the seat. In some arrangements, the top surface of the headrest  14  may be large enough to accommodate openings  38 . Wherever positioned, the openings  38  can be any desired shape, e.g., round, elongated. The openings  38  also can be relatively small or relatively large compared to the surface area of the side of the headrest  14  upon which they are located. For example, if a plurality of openings  38  are provided, the openings can be small compared to (in some cases, substantially smaller than) the surface area of the side of the headrest  14  upon which they are located. For example, the openings  38  can be less than about one-half the surface area of the side of the headrest  14  upon which they are located. In other embodiments, the opening(s)  38  can be relatively large, e.g., about one-half or more than, the surface area of the side of the headrest  14  upon which the openings are located. Also, although paired openings  38  are shown as having a similar configuration, e.g., size and shape, multiple openings  38  could be differently configured, e.g., one larger than and one smaller than one-half the surface area of the side upon which they are located.  
       FIG. 1  shows that an aperture cover  42  extends across the aperture  38  in one embodiment. The aperture cover  42  includes a plurality of discrete openings or venting holes  43  configured to permit air to pass into and out of the entertainment system mounting cavity  34 . Such airflow can be used to cool the entertainment system  18  or other components of the headrest entertainment assembly in thermal communication with the system  18 .  
       FIG. 1A  shows that in some embodiments, visible openings in the aperture cover  42  are not required. This arrangement can be used when other devices are provided to cool the entertainment system  18  such that airflow through the aperture cover  42  is not required. In some arrangements, the aperture cover  42  comprises a porous material membrane that appears solid, but permits airflow therethrough without visible openings. In other arrangements, the aperture cover  42  substantially blocks the aperture  38  where enhanced cooling is not needed, e.g., in entertainment systems that have components that emit low amounts of heat, tolerate greater heat levels, or are disposed in structures not sensitive to heat. In other arrangements, the aperture  38  is not provided. In certain of such arrangments, the material  39  that forms the side surface of the headrest  14  is itself perforated or porous, including structures similar to the venting holes  43  which may or may not be visible.  
       FIG. 13  shows that the headrest  14  can also include a seat mounting aperture  46  that can be located on a lower or bottom side of the headrest  14 . The seat mounting aperture  46  permits at least one component of the mounting system  22  to extend through the bottom side of the headrest  14  to an interior portion thereof. In one embodiment, the entertainment system mounting cavity  34  extends from the rear surface  32  of the headrest  14  to a location vertically above the seat mounting aperture  46 . This arrangement permits convenient assembly of the headrest  14  and the entertainment system  18  as discussed below. In some arrangements, a common cavity can be provided in which components of the mounting system  22  and of the entertainment system  18  can be positioned.  
       FIGS. 2-10  illustrate additional details of various embodiments of the a headrest entertainment assembly  10 .  
      In certain embodiments, the entertainment system  18  includes a signal source  78  and a monitor  200 . In other embodiments, the entertainment system  18  also includes a component cover  82 . In some embodiments, the entertainment system  18  further includes a monitor assembly  74 , which includes the monitor  200  and facilitates mounting of the monitor. As discussed below, the monitor assembly  74  provides one or more advantageous features, such as housing the monitor  200 , protecting the monitor from damage, locating associated components nearby, and enabling moving or pivoting of the monitor relative to the headrest  14 , as discussed further below.  
      In some embodiments, the entertainment system  18  also includes a component mounting frame  70  to which at least one of the monitor  200  and the signal source  78  are secured. In some arrangements, the mounting frame  70 , together with at least one component, provides a unitary construction. In one embodiment, the mounting frame  70  provides a rigid structure for mounting at least one component. In some arrangements, the mounting frame  70  is configured to be coupled with the monitor assembly  74  and the signal source  78 . As discussed further below, the mounting frame  70  also can be configured to be coupled with the cover  82  in some embodiments.  
      In one embodiment, the monitor assembly  74 , the signal source  78 , and the cover  82  are all coupled with the mounting frame  70  prior to insertion into the entertainment system mounting cavity  34 . Preassembling the monitor assembly  74 , the signal source  78 , and the cover  82  to the mounting frame  70  together is convenient for installation because an installer does not have to separately assemble these components, which can be easily damaged during the installation process if not handled carefully. Further details of techniques for assembling the headrest entertainment assembly  10  are discussed below.  
       FIG. 6  shows further details of one embodiment of the component mounting frame  70 . The component mounting frame  70  can include a monitor coupling portion  90  to which the monitor assembly  74  can be connected. Preferably, the monitor coupling portion  90  includes one or more hinge mounts  94 . Additional structures that can be combined with or incorporated into various embodiments of the assembly  10 , including structures for mounting the monitor assembly  74  to the mounting frame  70 , are discussed in U.S. Pat. No. 7,044,546, which is hereby expressly incorporated by reference herein. As discussed further below, the monitor coupling portion  90  preferably penmits at least a portion of the monitor assembly  74  to move into and out of the entertainment system mounting cavity  34 . In one embodiment, the monitor coupling portion  90  enables the monitor assembly  74  to pivot into and out of the entertainment system mounting cavity  34 . One arrangement provides a first elongated bracket  98  that includes a hinge mount  94 . The hinge mount  94  can include an aperture through which a fastener can be inserted. A second elongated bracket  102  can be coupled with the monitor assembly  74  and can be configured to pivot relative to the monitor assembly  74 . Preferably the elongate bracket  102  also includes a hinge mount having a similar configuration to the hinge mount  94 .  
      In one arrangement the monitor assembly  74  is coupled with the frame  70  by a hinge, which may comprise the bracket portions  98 ,  102 .  
      Coupling of the hinge mounts of the first and second elongate bracket portions  98 ,  102  can be facilitated by a suitable fastener, for example, a screw or bolt. In other arrangements, a detent arrangement can be relied upon, at least in part, to couple the first and second elongate portions  98 ,  102 . In some embodiments, means for securing the coupling of the first and second elongate portions, or of two portions of the coupling portion  90  can be provided. In one embodiment, the means includes a bonding grease that provides a tighter fit between the first and second elongate portions  98 ,  102 . Where provided, the bonding grease can take any suitable form. Preferably the bonding grease enables movement of the first and second elongate portions  98 ,  102  relative to each other upon application of a threshold force but prevents such movement upon forces less than the threshold force. Preferably, the securing means, e.g., the bonding grease, prevents the bracket portions  98 ,  102  from becoming separated from each other due to normal vibration that are induced in the monitor assembly  74  from the vehicle. In other embodiments, the securing means comprises a suitable adhesive which substantially prevents movement due to vibration or any other force.  
      When the first and second elongated brackets  98 ,  102  are coupled at the hinge mounts  94 , the monitor assembly  74  is able to pivot relative to the component mounting frame  70 . As shown in  FIGS. 5 and 6 , in one embodiment the component mounting frame  70  includes a plurality (e.g., two) monitor coupling portions  90 .  FIGS. 5 and 6  also show that in some embodiments a plurality of (e.g., two) hinges can be provided, such as by providing a second elongated bracket  102  on each side of the monitor assembly  74 . The illustrated arrangement permits the monitor assembly  74  to pivot about an axis A 1  extending through the second elongated brackets  102 . In particular, the monitor assembly  74  pivots about the axis A 1  at an end of the second elongated bracket  102  opposite an end that is coupled with the first elongate mounting bracket  98  in one embodiment.  
      As discussed further below, the pivoting of the monitor assembly  74  about the axis A 1  serves multiple functions. For example, pivoting enables the monitor  200  to be positioned in an orientation that is most comfortable for the user to view the video signal visible thereon. Pivoting also can enable convenient assembly, by providing an installation position in which the monitor assembly  74  is spaced from the frame  70  sufficiently to expose mounting structures, as discussed below.  
      The component mounting frame  70  preferably also includes a component cover mount portion  110 . The component cover mount portion  110  can comprise a bracket. In one embodiment, the component cover mount portion  110  is located behind (e.g., at a location further recessed from the surface  32  in the mounting cavity aperture  36  when the assembly  10  is assembled) the monitor coupling portion  90 . Preferably, the component cover mount portion  110  is located behind a front side of the component mounting frame  70 . In one embodiment, the component cover mount portion  110  extends to a location vertically above a component mounting area  114 . The component mounting area  114  provides a space or volume into which the signal source  78  can be positioned or mounted as discussed below. The component mounting area  114  can be partially or completely enclosed. In some embodiments, the component mounting area  114  is substantially exposed on a plurality of (e.g., on four) sides.  
       FIG. 2  shows that in one embodiment, the component cover mount portion  110  can include a movable mount  122  to which the cover  82  can be coupled. In one form, the movable mount  122  is a hinge. Preferably, the component cover mount portion  110  also includes a component access aperture  130 . The access aperture  130  provides access from a location outside the headrest entertainment assembly  10  to the component or signal source  78  located in the component mounting area  114 . As discussed further below, the signal source  78  is a DVD player in some embodiments. Accordingly, the component access aperture  130  can be configured as a slot through which a digital video disc (“DVD”) can be inserted. In one arrangement, the length of the slot is approximately equal to the width of the monitor  200 . In other embodiments, the signal source  78  can be any device that reads a form of media and produces a signal at least partially displayable on the monitor  200 . For example, the signal source  78  could also be a photo card reader, a MP 3  player, or other similar device.  
      The component mounting frame  70  also preferably includes one or more cooling system mounts  142 . One embodiment of the mounts  142  is shown in detail in  FIG. 9 . In one arrangement, the mount  142  comprises a pair of posts, each of which includes an elongated slot into which a component of the cooling system  86  can slide. The slots of the cooling system mounts  142  enable quick assembly of the cooling system  86  and the component mounting frame  70 . As shown in  FIG. 8 , the mounts  142  also can include holes formed at an end thereof spaced from the portion of the frame  70  adjacent the monitor assembly  74 . Preferably the holes in the mounts  142  are threaded to engage screws. In one assembly technique, as shown in  FIGS. 7A and 8A , a cooling fan  40  is positioned between the cooling system mounts  142 . The cooling fan  40  is secured in place with fasteners  49  that are advanced through threaded holes in the mounts  142 . In some embodiments, each fastener  49  comprises a flange of sufficient width to contact the cooling fan  40 . The flange applies a force to an upper surface of the cooling fan  40  which prevents the fan from sliding out of the mounts. In other embodiments, the fasteners are coupled with washers. In still other embodiments, the fasteners are coupled with a stiff, elongate piece that extends between the mounts  142  and contacts a top surface of the fan  40 . Each fastener may be secured to a hole in any suitable fashion, e.g., with threads, or a combination of threads and an adhesives whereby loosening of the fastener is minimized or prevented.  
      The component mounting frame  70  also preferably includes at least one off-set mount post  146 . In one embodiment, a plurality of (e.g., four) off-set mount post  146  is provided. In other embodiments, less than four (e.g., one, two, or three) off-set mount posts are provided adjacent an outer portion of the component mount area  114 . The off-set mount posts  146  are configured to couple with the mounting system  22 , as discussed further below. The off-set mount posts  146  can be configured as elongated structures enabling the component mounting frame  70  to be connected to or otherwise coupled with the mounting system  22 . Preferably, the off-set mount posts  146  are at least as long as, and preferably longer than the height or thickness of the signal source  78 . This arrangement provides sufficient clearance between the signal source  78  and the mounting system  22 .  
      The off-set mount posts  146  can be configured as conical structures. In one arrangement, the off-set mount posts  146  are elongated conical structures that have an aperture  147  formed at an end thereof spaced from the portion of the components mount frame  70  adjacent to the monitor assembly  74 . The aperture  147  in the off-set mount posts  146  preferably is configured for a connecting member (e.g., a screw) to be advanced therethrough to couple with the mounting system  22 , as discussed below. In another arrangement, the off-set mount posts  146  are elongated conical structures, with the aperture  147  formed at an end thereof spaced from the component mount frame  70 . In another arrangements the off-set mount posts  146  are hollow with an aperture  148  adjacent the portion of the components mount frame  70  adjacent to the monitor assembly  74 . As discussed further below, connecting members can be advanced through at least one of the apertures  147 ,  148  and received by the mounting system  22  to securely fasten the component mounting frame  70  to the mounting system  22 .  
      In one embodiment, the component mounting frame  70  also includes at least one signal source mounting portion  170 . In one embodiment, multiple signal source mounting portions  170  are provided. In one arrangement, four signal source mounting portions  170  are provided. In another arrangement, five signal source mounting portions  170  are provided. Signal source mounting portions  170  can be located adjacent an outer portion of the component mount area  114 . The one or more signal source mounting portions  170  are pegs that limit the movement of the signal source but do not coupled with the signal source  78 .  
      In other embodiments, the signal source mounting portions  170  include a bracket through which a fastening member (e.g., a screw or a bolt) can be inserted and to couple the signal source  78  with the component mounting frame  70 . In particular, a bracket can extend at least partially around the rear side of the component  78  (e.g., the side farthest from the portion of the component mounting frame adjacent to the monitor assembly  74 ) and be coupled thereto by at least one fastener (e.g., a screw). Preferably, in this arrangement, the bracket also includes a plurality of flanges that extend out to the signal source mounting post  170 . In some arrangements, connecting members can be advanced through these brackets and into threaded holes formed on exposed surfaces of the signal source mounting portions  170 .  
      The component mounting frame  70  is configured to facilitate other aspects and features of the entertainment system  18 . For example, the component mounting frame  70  can include a generally planar structure having one or more slots  172  formed therein. The slots  172  can be elongated and positioned close together. Also, a large number of slots  172  can be provided so as to reduce the weight of the component mounting frame  70 . In some arrangements, discussed below, the slots  172  function as vents directing heat generated by one or more components away from the entertainment system  18 . This feature is discussed more below in connection with an overall discussion of heat dissipation in the headrest entertainment assembly  10 .  
      In one embodiment, a monitor assembly cavity  182  is formed on a forward side of the component mounting frame  70 . The cavity  182  permits the monitor assembly  74  to be moved to a fully-closed position, which is a retracted position (shown in  FIG. 5 ). In a retracted position, the monitor assembly  74  may be positioned within the headrest  14 , e.g., at a location in front of the rear-facing side  32  thereof.  
      In one embodiment, the monitor  200  is one component of the monitor assembly  74 . The monitor  200  includes a display in one embodiment that can receive video signals from the signal source  78  and display images based on the video signals. In one embodiment, the display or monitor  200  is an active matrix TFT-LCD panel. Preferably, the monitor  200  is relatively thin, enabling the entertainment system  18  to be mounted in a standard headrest  14 . In one embodiment, the monitor  200  is a 7-inch TFT-LCD display. The monitor  200  can have a 16:9 widescreen format. The size of the monitor  200  can vary based on the size of the vehicle structure with which it is coupled, e.g., with the size of a headrest, within the scope of this application.  
      In one embodiment, the monitor  200  is mounted in a monitor housing  204 . The housing  204  provides various functions. For example, the monitor housing  204  enables users to handle the monitor assembly  74  without directly touching the monitor  200 . Also, the monitor housing  204  is able to absorb some shock to reduce the likelihood that normal interaction with occupants and objects in a vehicle will damage the monitor  200 . The monitor housing  204  also can host a plurality of controls  208 . The controls  208  can be conventional controls, such as would control the operation of the monitor  200  or an aspect of reproduction of the information from the signal source. In one arrangement, the controls  208  include a feature whereby transmission of a portion of the signal generated by the signal source (e.g., an audio component) is controlled, such as is described in U.S. patent application Ser. No. 10/361,744, filed on Feb. 7, 2003 and published as U.S. Patent Application Publication No. 2004/0080213 A1 on Apr. 29, 2004, the entire contents of which are hereby incorporated by reference herein.  
      The entertainment system  18  preferably also includes a locking device  212 . The locking device  212  can be mounted on the monitor assembly  74 , on the components mounting frame  20 , or a portion on each of the monitor assembly  74  and the components mounting frame  20 . In one embodiment, the locking device  212  includes a catch member  212   a  and an actuatable latch member  212   b . The catch member  212   a  can be located on the component mounting frame  20 , e.g., at least partially within the monitor assembly cavity  182 . The actuatable latch member  212   b  can be located on the monitor housing  204 , e.g., adjacent a lower edge thereof. The locking device  212  maintains the monitor  200  in a fully closed position (discussed further below) until the locking device  212  is unlocked, for example by actuating the movable latch  212   b . The locking device  212  also can take suitable, conventional forms.  
      In one embodiment, the monitor assembly  74  also includes a motion limiter device  220 . In one embodiment, the motion limiter device  220  includes a looped portion  221 A coupled at both ends with a mount fixture  222 B as shown in  FIG. 10 . The motion limiter device  220  can take other forms, e.g., as an S-hook, a chain, an elastic member, string, or other conventional coupler. The motion limiter device  220  can comprise an elongate member configured to be connected to the component mounting frame  70  at one end and to a mount portion  224  located on the monitor housing  204  at another end. For example, a post or other structure for coupling to one end of the motion limiter device  220  can be formed in the monitor assembly cavity  182 . In another arrangement, an aperture (e.g., a threaded hole) can be formed in the monitor assembly cavity  182  and the motion limiter device  220  can be coupled with the component mounting frame  70  via the aperture, e.g., with a fastener, an adhesive, a combination thereof, or other suitable means. In one embodiment, the mount portion  224  comprises a hook or other structure for coupling to an end of the motion limiter device  220 .  
      In one arrangement, the motion limiter  220  can be quickly disengaged to allow the monitor housing  204  to move to an assembly position, discussed below. This is facilitated in one arrangement by permanently affixing one end of the motion limiter  220  in the monitor assembly cavity  182  and looping the other end around a hook formed on the rear side of the monitor housing  204 .  
      As discussed above, the monitor assembly  74  is coupled with the mounting frame  70  in the preferred embodiment. In one arrangement, the monitor assembly  74  is configured to move relative to the component mounting frame  70 . Movement of the monitor assembly  74  can alter the orientation of the monitor  200 . The arrangement described above enables the monitor  200  of the monitor assembly  74  to move relative to the headrest  14  between a plurality of positions. For example in one embodiment, a fully-closed position is provided in which the monitor  200  is retracted into the monitor assembly cavity  182 . The fully-closed position is illustrated in  FIGS. 4 and 5 . Another position is illustrated in  FIGS. 1, 2 , and  3 , wherein the monitor  200  is tilted out such that a lower end thereof is spaced farther from the monitor assembly cavity  182  than is an upper portion of the monitor  200 .  
       FIG. 10  illustrates a third position in which the monitor  200  is in an installation position. In one embodiment, an installation position orients the monitor  200  at about a 90° angle relative to a plane that includes a base of the monitor assembly cavity  182 . This position advantageously provides access to the off-set mount posts  146 . For example, where the mounting component frame  70  is coupled with the mounting system  22 , discussed below, a fastening device can be inserted through a top portion of off-set mount post  146  (e.g., through the apertures  148 ). The top portion of the off-set mount post  146  corresponds to the base of the monitor assembly cavity  182  in one embodiment. Fastening devices can further be advanced to the bottom of the off-set mount posts  146  (e.g., through the apertures  147 ) and coupled with the mounting system  22 .  
      Preferably, the monitor assembly  74  is configured such that when the monitor  200  is positioned in an installation position, such as that shown in  FIG. 10 , the monitor  200  maintains its orientation relative to the base of the monitor assembly cavity  182 . Such an arrangement can be provided by configuring the monitor coupling portion  90  (e.g., the hinge mount(s)  94 ) such that the monitor  200  locks in place when in the installation position. In one arrangement, the motion limiter  220  can be a bracket or other compression member which holds the monitor  200  in the assembly orientation. One collapsible bracket arrangement is disclosed in U.S. Pat. No. 7,044,546, which is incorporated by reference above.  
      Preferably, the monitor assembly  74  also includes a plurality of apertures  222  formed in a rear surface thereof. The apertures in the rear surface of the monitor assembly  74  enable heat generated by the monitor  200  to be removed from the monitor assembly  74 . As discussed above, the component mounting frame  70  is configured to transfer such heat through apertures formed therein. The apertures  222  can be similar to the apertures  172 . In some embodiments, the configuration and position of the apertures  222  and the apertures  172  are the same so that heat can be efficiently vented from the monitor  200  and from the monitor assembly cavity  182 . Such heat can further be removed by way of a cooling system  86 , discussed below.  
       FIGS. 1 and 2  illustrate additional aspects of the cover  82 , described above. Preferably the cover  82  is configured to move relative to the component cover mount portion  110 . As discussed above, the movement can be by way of a movable mount  122  (e.g., a hinge). Preferably the cover  82  is configured to extend from the mount  122  to a location vertically over the component access aperture  130 . In one embodiment, the cover  82  extends from the mount  122  to a location vertically over the component access aperture  130  and over one or more control buttons  228  formed on or located adjacent the component cover mount portion  110 . The control buttons  228  can be associated with one or more components of the entertainment system  18 , e.g., one or more of the signal source  78  and the monitor  200 . For example, the control buttons  228  can control at least one aspect of at least one of an audio and a video component of a signal from the signal source  78 . In one embodiment, the cover  82  is configured to conform to a portion of the component cover mount portion  110  that is substantially parallel to a top surface of the headrest  14 . In another embodiment, the cover  82  is configured to conform to a portion of the component cover mount portion  110  that is substantially parallel to a transitional surface that extends between the top surface and the rear-facing surface  32  of the headrest  14 . The component cover  82  can be curved between a top and a transitional surface. Preferably the component cover  82  conforms to an outer surface of the headrest  14 .  
       FIG. 2  shows another feature of the cover  82 , which is provided in some embodiments. As discussed further below, the headrest entertainment assembly  10  includes a cooling system configured to efficiently extract heat generated by the components thereof from the headrest  14 . To this end, a cover  82  can be provided with one or more venting structures  230 . The venting structures  230  are configured to permit heat generated within the headrest, e.g., in the entertainment system mounting cavity  34 , to flow out to the outside of the headrest. In one embodiment, the venting structure  230  is provided with the plurality of perforations, which can be formed as an array of small holes. A substantial number of the holes in the array extend at least partially between a lower surface and an upper surface of the cover  82 . Accordingly, warm air adjacent the lower surface of the cover  82  can be more quickly transferred to the upper surface of the cover  82  and out of the headrest  14 . Although the venting structure  230  is shown in  FIG. 2  as a regular array of visible holes, the venting structure can be an irregular array, e.g., concentrated in a portion of the cover over a component that generates more heat.  
      The venting structure  230  can be configured to be substantially invisible to the naked eye of passengers in some arrangements. In one embodiment, the cover  82  is formed of a permeable material lacking visible holes but through which warm air can be quickly conveyed. Also, a cover  82  may include different numbers of holes in different regions based upon where greater heat is expected to be found. The function of the venting structures in combination with a cooling system will be discussed in greater detail below.  
      The cover  82  preferably has at least two positions. In a first position, the cover  82  is moved to conform to an upper surface  73  of the component mounting frame  70 . For example, the cover  82  can be moved to conform to, or to extend over or otherwise cover, the component cover mount portion  110 . In one embodiment, the cover  82  is moved to extend over the component access aperture  130 , which is a position sometimes referred to herein as the “closed position” of the cover  82 . The closed position advantageously limits access to the component access aperture  130 . In some arrangements, the top of the cover  82  is at an elevation below the top of the headrest  14 . In other arrangements, the top of the cover  82  is substantially flush with a top surface of the headrest  14 , which provides a sleek, continuous appearance as viewed from the front of the headrest  14 .  
      The cover  82  advantageously prevents foreign objects from extending or falling into the access aperture  130  when in the closed position. This feature can prevent such objects from becoming lodged in the signal source  78 . For example, a passengers sitting in the seat with which the headrest  14  is coupled may have long hair. Without the cover  82  in the closed position, the person&#39;s long hair could slip through the component access aperture  130  and into the signal source  78 . If the signal source  78  has moving parts and is operating, the person&#39;s might become wound around the moving parts. This could harm the person, the signal source, or both.  
       FIG. 2  shows that the cover  82  has at least one other position. In the second position, the cover  82  is moved away from the access aperture  130 . In this position, access is provided to the component access aperture  130  such that media (e.g., a DVD disc, photo card, etc.) can be inserted therethrough into the signal source  78 . The second position is sometimes referred to as an “open” position. The open position also is shown in more detail in the top view of  FIG. 3 . As shown in  FIG. 3 , the open position provides relatively unrestricted access to the component access aperture  130 .  
      As discussed above, in some embodiments the headrest entertainment assembly  10  is configured to efficiently remove heat from the entertainment system mounting cavity  34  of the headrest. The heat to be removed can be generated by components mounted therein, e.g., the monitor  200  and the signal source  78 . In one form, the headrest entertainment assembly  10  is configured for efficient removal of heat by including one or more openings  38  that provide fluid communication between the cavity  34  and the exterior of  
      In some embodiments, an airflow path is defined between a first aperture  38  that extends through an outer cover  41  of the headrest  14 , a second aperture  38 A that extends through the pillow  30 , and a third aperture  38 B that extends through an entertainment system mounting bracket  264 , as shown in  FIG. 12 . Further enhanced cooling can be provided by including the first, second, and third apertures  38 ,  38 A, and  38 B on both sides of the headrest entertainment assembly  10 . The outer cover  41  may comprise fabric, such as solid or perforated leather, or other suitable material. In some embodiments, the aperture cover  42  extends across the aperture  38 , as discussed above. The aperture cover  42  may be attached to the outer cover  41  by any suitable means, such as, for example, by stitching. In some arrangements, the aperture cover  42  and outer cover  41  form one unitary piece of material.  
      In certain embodiments, an opening in the pillow  30  aligns with the opening in the outer cover  41 . The opening in the pillow  30  may be formed by removing a portion of the pillow, such as by cutting out or punching out the portion. In some embodiments, the opening is formed during fabrication of the pillow. For example, the mold of a blow-molded pillow  30  may be shaped to provide for an opening in the pillow once the mold is removed.  
      In certain embodiments, an opening in the entertainment system mounting bracket  264  is aligned with the openings in the outer cover  41  and the pillow  30 . As discussed above, the off-set mounting posts  146  may be longer than the height or thickness of the signal source  78 . In such arrangements, when the mounting posts  146  are fastened to the entertainment system mounting bracket, a cavity is formed between the signal source  78  and the entertainment system mounting bracket  264 . In some embodiments, this cavity is in fluid communication with the airflow path defined through the apertures  38 ,  38 A, and  38 B, allowing heated air to escape from the cavity through the aperture.  
      In some embodiments, the openings in the entertainment system mounting bracket  264 , the outer cover  41 , and the pillow  30  may be offset from each other. In further embodiments, the airflow path is defined within a conduit, e.g., a tube, extending through the openings.  
      In various embodiments, as discussed above, a plurality of apertures  38  are provided to enhance cooling by creating cross-flow past heat-generating or past heat-sensitive components. As shown in  FIG. 12 , in some configurations, the apertures may extend through opposing sides of the outer cover  41 , the pillow  30 , and the entertainment system mounting bracket  264  of the headrest  14 . In some embodiments, a cavity is formed between the signal source  78  and the entertainment system mounting bracket  264 . The cavity may be in fluid communication with the plurality of apertures  38 , thereby allowing a cross-flow of air through the headrest  14 . While in some cases, a natural cross-flow is sufficient to remove unwanted heat from the headrest  14 , various embodiments provide further enhanced cooling by the structures discussed above. For example, in one embodiment, a cooling fan  40  is coupled with the cooling system mounts  142  as described above.  
       FIG. 15  illustrates one embodiment of a cooling fan  40 . The cooling fan  40  comprises a mounting bracket or housing  40 A and a plurality of blades  40 B. The housing  40 A defines a volume within which the plurality of blades  40 B can rotate. In certain embodiments, the housing  40 A comprises a perimeter portion  40 C extending around the periphery of the cooling fan  40  and a central portion  40 D that covers a junction (not shown) of the blades  40 B. The junction can be a rotatably mounted hub in one embodiment. In some embodiments, the perimeter portion  40 C and central portion  40 D are connected by one or more support members  40 E. The perimeter portion  40 C, central portion  40 D, and support members  40 E can define a plurality of openings  40 F through which air can flow.  
      In certain embodiments, the housing  40 A is sized to be inserted between the cooling system mounts  142 , as described above with respect to  FIGS. 7-9 . In some embodiments, the width of the housing  40 A is slightly less than the distance between the mounts  142  and the thickness of the housing is slightly less than the width of the elongated slots of the mounts, thereby ensuring a snug fit of the housing within the mounts. In some embodiments, the width of the housing  40 A is between about 25 millimeters and about 60 millimeters and the thickness is between about  5  millimeters and 15 millimeters. In one embodiment, the width of the housing  40 A is about 40 millimeters and the thickness is about 10.5 millimeters. As shown in  FIG. 15 , in some embodiments, the housing  40 A may be substantially square. In one such embodiment, the width and height of the housing  40 A are each about 40 millimeters and the thickness is about 10.5 millimeters.  
      In some embodiments, the housing  40 A comprises a plurality of openings  40 G,  40 H. The openings  40 G may provide an alternative means of mounting the cooling fan  40  to the component mounting frame  70 . In some configurations, fasteners are inserted through the openings  40 G to secure the housing  40 A to a portion of the component mounting frame  70 . In some embodiments, the openings  40 G,  40 H reduce the weight of the housing  40 A without compromising the structural integrity of the housing. The openings  40 G,  40 H may allow venting in addition to that provided by other openings  40 F of the housing  40 A.  
      The blades  40 B may meet at a common junction (not shown). In some embodiments, the junction is coupled with the central portion  40 D of the housing  40 A in a manner that allows rotation. In the embodiment depicted in  FIG. 15 , the axis of rotation is about a line extending perpendicularly through a plane defined by the perimeter portion  40 C. In some configurations, the blades  40 D rotate clockwise about the axis, and in others, the blades rotate counter-clockwise.  
      In some configurations, it is desirable that the housing  40 A and blades  40 B be substantially rigid and lightweight. The housing  40 A and the blades  40 B may comprise any suitable material, such as plastic.  
      In certain embodiments, the cooling fan  40  comprises a lead  401  for coupling with a power source (not shown). In some embodiments, the power source operates between about 9.5 Volts and about 15 Volts. The power source provides a direct current in some configurations. The cooling fan  40  can be powered by the car battery. In some embodiments, a battery dedicated to the headrest entertainment assembly  10  powers the cooling fan  40 .  
      The cooling fan  40  can be oriented or configured to force a cooling fluid, e.g., air, into the cavity  34  to enhance convective cooling of heat generating or heat sensitive components located therein. The cooling fan  40  can be oriented or configured to draw a cooling fluid, e.g., air, out of the cavity  34  to enhance convective cooling. Also, a plurality of fans  40  can be used, e.g., one to force air into an aperture  38  and another to draw air out through another opening, enhancing cooling.  
      The openings  38  can also be used in combination with other venting structures, such as the venting structures  230  discussed above. This arrangement permits cross-flow of air and allows hot air rising within the cavity  32  to escape therefrom. In another embodiment, the openings  38  and the venting structure  230  are combined with one or more fans.  
      As discussed above, further enhancement of the cooling system can be incorporated into one or more support structures located inside the cavity  34 . For example, the slots and apertures  172  and  222  are configured to permit air to move away from components that may be heat generators or heat sensitive, e.g., the monitor  200  or the signal source  78 . The slots  172  can be aligned with the apertures  222  to enhance this movement away from such components and into the stream of flow created by the at least one aperture  38 .  
      Additional cooling can be achieved forward of the entertainment system  18 . For example, in one embodiment, at least one component of the mounting system  22  includes perforations or a plurality of small holes  304  through which the movement of hot air can be enhanced. This arrangement fosters additional convective cooling on the forward side of the signal source  78  in the illustrated embodiment.  
      Various structures have been discussed above that facilitate the efficient removal of heat from the headrest entertainment assembly  10 . Efficient removal of heat is facilitated in some embodiments by providing enhanced flow within the headrest  14 , e.g., in the entertainment system mounting cavity  34 . In the figures, structures that enhance cooling, e.g., by heat transfer by convection, are further illustrates with arrows indicating airflow. Although arrowheads generally indicate the direction of airflow (e.g., from the tail of the arrow to the head), some structures permit airflow to be directed toward the head or toward the tail of the arrow shown.  
      With reference to  FIGS. 1, 2 ,  12 , and  13 , an arrow  234   a  indicates airflow through the aperture  38  (or apertures  38 ,  38 A,  38 B). In one arrangement, the airflow indicated by the arrow  234   a  is through the aperture  38  into the cavity  34 . In some applications where relatively little heat is generated or the electronics housed in the headrest  14  are resistant to heat-induced failure, such flow may be sufficient to cool the components. In other embodiments, the cooling fan  40  is mounted to the cooling system mounts  142  such that it is adjacent to the aperture  38 . In this arrangement, greater amounts of airflow can be directed into the cavity  34 , as indicated by the arrow  234   a . An arrow  234   b  indicates that airflow also can escape from or be forced out of the cavity  34  through another aperture  38  (or set of apertures  38 B,  38 A,  38 ), which can be located on an opposite side of the headrest  14 . This advantageously creates cross-flow, which is a greater amount of airflow than would be provided through the cavity  34  in the absence of the aperture  38  or another venting structure as described herein.  
      In most embodiments, cross-flow is enhanced by providing a plurality of pathways for airflow into and out of the cavity  34 . In the embodiment of  FIG. 13 , two apertures  38  are provided to enhance cross-flow through the cavity  34 . In another embodiment, the venting structures  230  are a second airflow pathway enabling air to escape from the headrest  14 , permitting a greater amount of airflow through the headrest.  FIGS. 1 and 2  illustrate that cross-flow is a broad term that includes the positioning of multiple venting structure or apertures on sides of the headrest  14  that are not directly across from each other. Cross-flow enhancing arrangements can be provided by providing at least two venting structures on any combination of the side, the top, or the bottom of the headrest  14 . In some embodiments, a plurality of venting structure are provided on the same side of the headrest  14 , e.g., one adjacent the fan  40  and one spaced therefrom.  
      As discussed above, the venting structures  230  are particularly beneficial in providing for egress of heat by convection from the cavity  34  because hot air will rise toward the top of the cavity. One system that provides particularly rapid cooling of the cavity  34  incorporates a plurality of apertures formed on surfaces of the headrest  14  and the venting structure  230  on a top surface of the assembly  10 , e.g., on the aperture cover  42 .  
      In some applications the assembly  10  includes a heat management system that incorporates external venting structures, e.g., at least one of the aperture(s)  38  and the venting structure  230 , and one or more internal structure configured to enhance heat transfer away from at least one heat generating component. For example, as discussed above, the heat management system can include heat transfer enhancing structures formed on electronic components or housings therefore, such as the apertures  222  formed in the monitor assembly  74 . The heat management system also can include heat transfer enhancing structures formed on structures that are partly or occasionally exposed to the external ambient, such as the slots  172  formed in the component mounting frame  70 . The heat management system also can include heat transfer enhancing structures formed on structures that are enclosed in or at least substantially entirely enclosed in the cavity  34 , e.g., the holes  304  formed in the entertainment system mounting bracket  264 .  
      By combining the venting structures and other heat transfer enhancing structures, more electronic devices can be packed into the confined space of the headrest  14 , whereby greater functionality and performance is provided to the assembly  10 .  
      The structures discussed herein for efficiently removing heat from the headrest entertainment assembly  10  provide several advantages. For example, by providing sufficient cooling, multiple components can be mounted within the cavity  34  while maintaining levels of heat that are acceptable to the passenger. Also, the level of heat in the cavity  34  is kept at an acceptable level to reduce component failure due to excessive heating. These and other features make the devices disclosed and claimed herein particularly advantageous.  
      As discussed above, the headrest entertainment assembly  10  also includes a mounting system  22  that facilitates installation of the entertainment system in the entertainment system mounting cavity  34  of the headrest  14 .  
      In one arrangement, the mounting system  22  includes one or more (e.g., two) seat post  26 , a pillow mounting bracket  260 , an entertainment system mounting bracket  264 , and an entertainment system mounting feature  268 . In one arrangement, as discussed above, the entertainment system mounting bracket  264  is perforated, e.g., with the plurality of small holes formed therein.  
      In one arrangement, the entertainment system mounting feature  268  comprises a plurality of posts, e.g., four posts, which extend through corresponding apertures in the entertainment system mounting bracket  264 . The posts  268  can be threaded to facilitate fastining of the perforated entertainment system mounting bracket  264  to the pillow mounting bracket  260 . In one arrangement, the pillow mounting bracket  260  includes a recess, which may be a substantially U-shaped recess, formed on an upper side of the pillow mounting bracket. To give the headrest  14  a more solid feel, a spacer member  276  may be positioned between the pillow  30  and the entertainment system mounting bracket  264 .  
      Further features of the pillow mounting bracket  260  increase the strength of the headrest entertainment assembly  10 , particularly of the headrest  14 . In one embodiment, as shown in  FIG. 13 , the pillow mounting bracket  260  includes a first plate-like portion  265 A and a second plate-like portion  265 B. To provide additional strength to the pillow mounting bracket  260 , at least one of the plate-like portions  265 A,  265 B is provided with one or more reinforcing members  266  to increase the strength of the portion of the plate-like portions  265 A,  265 B that resides between the posts  26 . In one arrangement, the reinforcing member  266  comprises an elongated depression or channel formed in at least one of the plate like portions  265 A,  265 B. The depression or channel increases the resistance of the plate-like portion to bending or creasing along a plane parallel to the posts in the event of a collision. This arrangement provides other advantages. For example, it can permit other components to be less bulky. For example, a thinner-walled post  26  could be used. As discussed below, providing a thinner walled post  26  increases clearance for routing cables, which makes assembly of the headrest entertainment assembly  10  much easier.  
       FIG. 14  shows an axis A 2  about which the pillow mounting bracket  260  can be rotated relative to the seat post  26 . The headrest  14  can thus be tilted relative to a seat with which it is coupled. In other embodiments, tilting about the axis A 2  is not required and is not provided.  
       FIGS. 12 and 13  illustrate a first stage of one method of assembling the headrest entertainment assembly  10 . In the first stage, the pillow  30  and other portions of the headrest  14  generally defining the cavity  34  are provided. The portion of the headrest  14  can be made in any suitable fashion, e.g., by molding. However, as discussed above, this portion of the headrest  14  is a separate, discrete portion of the headrest entertainment assembly  10 , e.g., it can be shipped, stored, and inventoried separately from the other components of the assembly  10 . As discussed above, this portion of the headrest  14  has a seat mounting aperture  46  through which a pillow mounting bracket  260  can be inserted.  FIG. 12  illustrates that in one embodiment, the pillow mounting bracket  260  is inserted through the aperture  46  until the U-shaped portion  274  engages the spacer member  276 .  
      In one technique, thereafter the entertainment system mounting bracket  264  is coupled with the pillow mounting bracket  260  in the cavity  34 .  FIGS. 5 and 12  illustrate that after the entertainment system mounting bracket  264  is coupled with the pillow mounting bracket  260 , the pillow mounting bracket is not able to be separated from the portion of the headrest  14  including the pillow  30 . This is one technique for assembling the mounting system  22  to the portion of the headrest  14  including the pillow  30 . In one embodiment, the entertainment system mounting bracket  264  includes a passage  308  for routing cables from the entertainment system  18 , as discussed below.  
      In some embodiments, techniques for quickly and efficiently assembling the headrest entertainment assembly  10  involve routing signal cables through the mounting system  22 . In particular, one advantageous technique routes signal cables through one or more mount posts  26 .  
      Further techniques for assembling the headrest entertainment assembly  10  are discussed above. In particular, the monitor assembly  74  can be coupled with the frame  70  as discussed above in connection with  FIGS. 6-9 . Thereafter, the monitor  200  can be tilted to an installation position, such as is shown in  FIG. 10 . Thereafter fasteners and the motion limiter  220  can be applied to couple the frame  70  to the mounting system  22 .  
       FIG. 16  schematically illustrates one embodiment of a video system  300  comprising multiple entertainment systems  18 . In certain embodiments, each entertainment system  18  is mounted in the headrest  14  of a vehicle. Each entertainment system  18  can be coupled with an entertainment system cable  310  capable of extending through the post  26  of the headrest  14 . In some embodiments, each entertainment system cable  310  comprises an entertainment system plug or connector  311  sized and configured to extend through the post  26 . In certain embodiments, each entertainment system connector  311  can be configured to couple with an adapter  312 . In some embodiments, the adapter  312  comprises adapter plugs or connectors  313  configured to couple with the entertainment system connectors  311 . The adapter  312  can further comprise one or more primary adapter cables  314  coupled with the adapter connectors  313 . In certain configurations, the one or more primary adapter cables  314  and an auxiliary adapter cable  318  extend from a junction  316 . In some embodiments, the adapter  312  is coupled with a power source  320 . In further embodiments, the adapter  312  is coupled with the power source  320  via a noise suppressor  325 .  
       FIG. 16A  illustrates one advantageous embodiment of the adapter  312 . In the illustrated embodiment, the adapter  312  comprises a single unit having a first branch  331 , a second branch  332 , and a third branch  333 . Each of the first and second branches  331 ,  332  includes a primary adapter cable  314  having the junction  316  at one end and an adapter connector  313  at another end. The third branch  333  includes a secondary adapter cable  318  having the junction  316  at one end and a heat shrink tube  340  at another end. As further described below, each of the primary and secondary adapter cables  314 ,  318  can include one or more branches of communication lines and/or electrical lines. In some embodiments, the junction  316  includes a heat shrink tube that tightly engages the primary and secondary adapter cables  314 ,  318 .  
      In the illustrated embodiment, one branch of a first electrical line  351  and one branch of a second electrical line  352  extend from the tube  340 , which in some embodiments, is a heat shrink tube. In certain embodiments, the first electrical line  351  comprises a fuse  355  and an interlocking connector  361  configured to couple with the noise suppressor  325 . In certain embodiments, the second electrical line  352  comprises an interlocking connector  362  configured to couple with the noise suppressor  325 . The noise suppressor  325  can be coupled with the power source  320 .  
      With reference to  FIG. 16B , in some embodiments, each adapter connector  313  includes a coupling interface  370  for coupling with an entertainment system connector  311 . In certain advantageous embodiments, the coupling interface  370  includes any suitable interface, such as a pin/sheath or a plug/socket interface, for creating a mechanical and electrical connection between an adapter connector  313  and an entertainment system connector  311 . In the illustrated embodiment, the coupling interface  370  of the adapter connector  313  comprises seven pins for coupling with an entertainment system connector having seven sheaths.  
      As described in further detail below, in certain embodiments, the adapter  312  allows entertainment systems  18  to be interconnected rapidly and efficiently. In some advantageous embodiments, the adapter  312  couples an output of a first entertainment system  18  with an input of a second entertainment system  18 , and couples an output of the second entertainment system  18  with an input of the first entertainment system  18 . In many embodiments, the entertainment system connectors  311  of the entertainment systems  18  have the same configuration, and the first branch  331  or the second branch  332  of the adapter  312  can be coupled with either the first or second entertainment system  18 . Accordingly, the first and second adapter branches  331 ,  332  can be interchangeable, which can greatly facilitate installation of multiple entertainment systems  18 . Additionally, the adapter can couple multiple entertainment systems  18  with a power source via a single set of electrical lines, which can also facilitate installation.  
      As schematically illustrated in  FIG. 17 , in certain embodiments, the entertainment system  18  comprises the signal source  78  and the monitor  200 . The signal source  78  is capable of producing a signal, at least a portion of which is displayable on the monitor  200 . In some embodiments, the signal source  78  is a device that reads a form of media and produces a signal at least partially displayable on the monitor  200 . For example, the signal source  78  can be a DVD player, a photo card reader, or an MP3 player.  
      In some configurations, the entertainment system  18  comprises an output  421  for communicating the signal produced by the signal source  78  to a device other than the monitor  200 . For example, via the output  421  of one entertainment system  18 , the signal from the signal source  78  can be communicated to a separate entertainment system  18 . In some embodiments, the monitor  200  of the entertainment system  18  comprises the output  421 . In other embodiments, the signal source  78  of the entertainment system  18  comprises the output  421 . In still other embodiments, a pin, plug, or other coupling device of the entertainment system connector  311  comprises the output  421 .  
      In some configurations, the entertainment system  18  comprises an input  423  for receiving a signal. In some arrangements, the signal received via the input  423  of one entertainment system  18  is generated by the signal source  78  of a separate entertainment system  18 . In some embodiments, the monitor  200  of the entertainment system  18  comprises the input  423 . In other embodiments, the signal source  78  of the entertainment system  18  comprises the input  423 . In still other embodiments, a pin, plug, or other coupling device of the entertainment system connector  311  comprises the input  423 . Accordingly, in some embodiments, a single connector  311  comprises the input  423  and the output  421  of the entertainment system  18 .  
      In certain embodiments, the monitor  200  of the entertainment system  18  is operable in more than one state. In some embodiments, the monitor  200  displays at least a portion of a signal communicated via the output  421  when in one state, and displays at least a portion of a signal received via the input  423  when in another state. For example, in some preferred embodiments, the video system  300  comprises two entertainment systems  18  generating separate signals. In a first state, the monitor  200  of the first entertainment system  18  displays at least a portion of a first signal generated by the first signal source  78  that is communicated via the output  421 , and in a second state, the monitor  200  displays at least a portion of a second signal generated by the second system  18  and obtained via the input  423 . In some embodiments, the entertainment system  18  comprises multiple inputs  423  and/or multiple outputs  421 . In certain of such embodiments, the monitor  200  can operate in multiple states, displaying the signal associated with each input  423  or output  421  of the entertainment system  18  in at least one separate state.  
      In some embodiments, the entertainment system  18  comprises one or more transmitters  425  for delivering audio informnation. In certain preferred embodiments, the transmitter  425  operates at infrared frequencies. In other embodiments, the transmitter  425  operates at radio frequencies. In some embodiments, the video system  300  comprises two entertainment systems  18 , each one comprising a transmitter  425 . In certain of such embodiments, the first entertainment system  18  is configured to generate a first video signal and a first audio signal, to deliver at least a portion of the first video signal via the first output  421 , to deliver at least a portion of the first audio signal via the first transmitter  425 , and/or to receive at least a portion of a second video signal via the first input  423 . In certain embodiments, the second entertainment system is configured to generate the second video signal and a second audio signal, to deliver at least a portion of the second video signal via the second output  421 , to deliver at least a portion of the second audio signal via the second transmitter  425  (preferably at a frequency different from that employed by the first transmitter  425 ), and/or to receive at least a portion of the first video signal via the second input  423 . By selecting among operating states, a user can access the first or second video signal via the monitor  200  of either system  18 . The user can also select the first or second audio signal via a receiver, such as a radio within the vehicle or a personal headset, by tuning to the transmitted frequency.  
      In certain embodiments, signals are communicated from and/or delivered to the entertainment system  18  via the entertainment system cable  310 . The entertainment system cable  310  can comprise one or more communication lines  430 , such as, for example, electrical wires, optical fibers, and/or any other suitable lines for communicating information. In certain embodiments, the input  423  and the output  421  of the entertainment system  18  are each coupled with a separate communication line  430 . Accordingly, in some embodiments the entertainment system cable  310  comprises one communication line  430  dedicated to the input  423  and another communication line  430  dedicated to the output  421  of the entertainment system  18 . In other embodiments, the entertainment system cable  310  comprises a separate communication line  430  for each of multiple inputs  423  and multiple outputs of the entertainment system  18 .  
      In some embodiments, the entertainment system cable  310  comprises one or more electrical lines  432  for delivering power to the entertainment system  18 . The electrical lines  432  can comprise electrical wires or any other suitable lines for transmitting power. The entertainment system cable  310  can also include one or more electrical lines  432  for electrically grounding the entertainment system  18 . For example, in some configurations, the entertainment system cable  310  comprises one electrical line  432  for coupling the system  18  with a ground of the power source  320  and comprises another electrical line  432  providing a common reference or common ground for the entertainment systems  18 .  
      As illustrated in  FIG. 18 , in certain embodiments, the entertainment system connector  311  comprises a coupling interface  433 . The coupling interface  433  can include any suitable interface, such as a pin/sheath or a plug/socket interface, for creating a connection with a coupling interface  370  of an adapter connector  313 . The connection can be a mechanical connection, a friction fit, or some other suitable connection. In some embodiments, the coupling interface  433  comprises a plurality of couplers  434 , which are sheaths in the illustrated embodiment. In certain arrangements, a separate coupler or sheath  434  is coupled with each communication line  430  or electrical line  432  of the entertainment system cable  310 . For example, in the illustrated embodiment, one sheath  434   a  is coupled with a communication line  430  dedicated to the output  421  of the entertainment system  18 , and another sheath  434   b  is coupled with a communication line  430  dedicated to the input  423  of the entertainment system  18 . In some preferred configurations, each sheath  434  is sized to contact an outer surface of a pin, as described below.  
      In certain embodiments, the entertainment system connector  311  is sized and configured to extend through the post  26  of the headrest  14 . As described above, the inner cross-sectional size (e.g., diameter) of a hollow passage extending through the post  26  can be increased to allow the passage therethrough of a larger entertainment system connector  311  comprising a greater number of sheaths  434 . In some situations, this can be accomplished by increasing the size (e.g., the inner and outer diameter) of the posts  26 . In other situations, the wall thickness of the posts  26  can be decreased. In the embodiment illustrated in  FIG. 18 , the entertainment system connector  311  comprises seven sheaths  434 . Other embodiments can comprise more or fewer sheaths  434 .  
      With continued reference to  FIG. 18 , in certain embodiments, an adapter connector  313  comprises a coupling interface  370  having a plurality of couplers  436 , which are pins in the illustrated embodiment, that are configured to cooperate with the sheaths  434 . As noted above, arrangements other than pin/sheath or plug/socket interfaces are possible for the coupling interfaces  370 ,  433 . In the illustrated embodiment, each of the couplers or pins  436   a - g  is sized and dimensioned to fit snugly within a corresponding sheath  434   a - g . In preferred embodiments, at least a portion of each pin  436  and each sheath  434  is capable of conducting electrical signals. The conducting portions of the pins  436  and sheaths  434  preferably contact one another when the entertainment system connector  311  and adapter connector  313  are coupled.  
      In other embodiments, the entertainment system connector  311  comprises pins  436  and the adapter connector comprises sheaths  434 . In still other embodiments, each connector  311 ,  313  comprises a combination of pins  436  and sheaths  434 . In some configurations, the connectors  311 ,  313  comprise complementary connection interface members configured to transmit optical signals, rather than electrical signals.  
      In certain embodiments, the connector  313  comprises a sleeve  435   a . In some embodiments, the pins  436  are housed within the sleeve  435   a  and do not extend beyond a rim  435   b  (also shown in  FIG. 19 ) of the sleeve  435   a . Accordingly, in some embodiments, the sleeve  435   a  can protect the pins  436  from being bent or otherwise damaged prior to coupling with the sheaths  434  of the connector  311 . In many embodiments, the connector  311  is sized and configured to fit snugly within the sleeve  435   a  when coupled with the connector  313 .  
      In certain embodiments, the entertainment system connector  311  and adapter connecter  313  can be joined only when the sheaths  434  and the pins  436  are properly aligned. As shown in the illustrated embodiment, the adapter connector  313  can comprise a ridge  437  that extends inwardly from the sleeve  435   a  of the connector  313 . In certain embodiments, the ridge  437  is sized and shaped to fit in a channel  438  of the entertainment system connector  311 . As illustrated in  FIG. 19 , the adapter connector  313  can comprise an indicator  439 , such as an imprinted or painted arrow, on an outer surface thereof for demonstrating the location of the ridge  437  on an inner surface thereof. In many embodiments, the indicator  439  permits proper connection of the entertainment system connector  311  and the adapter connector  313  without inspection of the inner surface of the adapter connector  313 , thereby facilitating the connection process.  
      As schematically illustrated in  FIG. 20 , in certain embodiments, the adapter connectors  313  are coupled with one or more primary adapter cables  314 . The primary adapter cables  314  can comprise communication lines  430 , electrical lines  432 , and/or branches thereof. As discussed below, in some embodiments, one end of one branch of a communication line  430  is coupled with one pin  436  of an adapter connector  313  and one end of another branch of the communication line  430  is coupled with one pin  436  of another adapter connector  313 . Similarly, one end of one branch of an electrical line  432  can be coupled with one pin  436  of an adapter connector  313  and one end of another branch of the electrical line  432  can be coupled with one pin  436  of another adapter connector  313 .  
      In certain preferred embodiments, the adapter  312  comprises two adapter connectors  313 . In some configurations, each adapter connector  313  comprises five or more pins  436 . In preferred embodiments, each adapter connector  313  comprises the same configuration of pins  436 . In the illustrated embodiment, one end of one branch of an electrical line  432   c  is coupled with the pin  436   c  of a first adapter connector  313 , and one end of another branch of the electrical line  432   c  is coupled with the pin  436   c  of a second adapter connector  313 . The electrical line  432   c  thereby couples both pins  436   c . Similarly, an electrical line  432   d  couples both pins  436   d , and another electrical line  432   e  couples both pins  436   e . Accordingly, the two adapter connectors  313  are interchangeable with respect to the pins  436   c - e  of each connector. As used herein the term interchangeable is a broad term used in its ordinary sense and includes, without limitation, the ability to use one connector in place of another connector.  
      In the illustrated embodiment, one communication line  430  couples the pin  436   a  of the first adapter connector  313  with the pin  436   b  of the second adapter connector  313 . Similarly, a second communication line  430  couples the pin  436   b  of the first adapter connector  313  with the pin  436   a  of the second adapter connector  313 . Accordingly, the two adapter connectors  313  are interchangeable with respect to the pins  436   a  and  436   b.    
      Advantageously, the inverted configuration of the pins  436   a,b  of the adapters facilitates the coupling of inputs  423  and outputs  421  of entertainment systems  18 . In certain embodiments, the video system  300  comprises two entertainment systems  18  having substantially similar entertainment system connectors  311 . Each entertainment system connector  311  has the same configuration of sheaths  434 , i.e., for each connector  311 , the sheath  434   a  is coupled with the output  421  of the entertainment system  18  and the sheath  434   b  is coupled with the input  423  of the entertainment system  18 , (see, e.g.,  FIGS. 17 and 18 ). Connection of the adapter  312  with the two entertainment system connectors  311  effectively couples the input  423  of one entertainment system  18  with the output  421  of the other entertainment system  18 , and vice versa.  
      In some embodiments, the adapter  312  comprises adapter connectors  313  each having seven pins  436 . In certain of such embodiments, the adapter connectors  313  are interchangeable. Certain of such embodiments resemble the illustrated five-pin adapter described above, but comprise two additional communication lines  430  running between the adapter connectors  313 . In certain embodiments, the seven-pin adapter  312  is used in a video system  300  comprising two entertainment systems  18 , each having two inputs  423  and two outputs  421 . The additional communication lines  430  can allow coupling of a second output  421  of the first entertainment system  18  with a second input  423  of the second entertainment system  18 , and allow coupling of a second input  423  of the first entertainment system with a second output  421  of the second entertainment system  18 .  
      The interchangeable nature of the adapter connectors  313  can advantageously reduce the time required to install video systems  300 , as no time is lost identifying which adapter connector  313  corresponds with the entertainment system connector  311  of a given entertainment system  18 . Furthermore, interchangeable adapter connectors  313  can reduce the risk of improper installation which, in addition to increasing the overall installation time of a video system  300 , could ultimately damage the video system  300 . Additionally, the adapter connectors  313  can allow interoperability among monitors  200  of different makes and models by providing a standard interface for coupling with the input  423  and output  421  of any monitor  200 .  
      The use of adapters  312  to route signals from one entertainment system  18  to another can also provide advantages over the use of a separate signal source selection unit, such as a device that accepts signals from entertainment systems  18 , DVD players, video game consoles, and/or other signal sources, and can allow a user to select among the various signals received by the unit. Signal source selection units can be expensive. Furthermore, such units can be costly to install, especially in the aftermarket where vehicles may not be configured to house signal source selection units. Additionally, some vehicles lack the required space for signal source selection units, or the units take up more space than desired by vehicle owners. The installation of such units can also be time-consuming. The use of adapters  312  can reduce or eliminate each of these problems.  
      With continued reference to  FIG. 20 , in certain embodiments, the secondary adapter cable  318  comprises an additional branch of the electrical line  432   d  and an additional branch of the electrical line  432   e . In some embodiments, the electrical lines  432   d  and  432   e  are coupled with with the power source  320 . The power source  320  can be an alternating current or direct current source. In some embodiments, the power source  320  comprises the power source of a vehicle. In other embodiments, the power source  320  is dedicated to the video system  300 . In some embodiments, the electrical line  432   d  is connected to the ground of the power source  320 . In other embodiments, the electrical line  432   d  is connected to some other suitable ground.  
      As illustrated in  FIG. 20A , in certain embodiments, the electrical lines  432   d  and  432   e  are coupled with the noise suppressor  325 . In some embodiments, the noise suppressor  325  comprises an input power lead  326 , an input ground lead  327 , an input accessory lead  328 , an output power lead  329  and an output ground lead  330 . In some embodiments, the electrical line  432   e  is coupled with the output power lead  329  and the electrical line  432   d  is coupled with the output ground lead  330 . In some embodiments, the each of the leads  329 ,  330  comprises a first interlocking connector  371  and each of the lines  432   d ,  432   e  comprises a second interlocking connector  372 . The first and second interlocking connectors  371 ,  372  can be configured to engage one another by friction fit or by some other suitable method. In some embodiments, the interlocking connectors  371 ,  372  are coupled via a fastener, such as a clip or a screw.  
      In some embodiments, the noise suppressor  325  is coupled with the power source of a vehicle. The input power lead  326  can be coupled with a power line of the vehicle, the input ground lead  327  can be grounded in a suitable manner, and the input accessory lead  328  can be coupled with the accessory power line of the vehicle. In many embodiments, the noise suppressor filters and/or reduces hum from the engine power line, thereby providing a smoother waveform to the output power lead  329  than is received from the input power lead  326 .  
      The input accessory lead  328  can serve a variety of functions. In one preferred embodiment, the input accessory lead  328  signals that a vehicle is being shut off, tripping circuitry within the noise suppressor  325  to reduce power output to the entertainment systems  18 . In some embodiments, the reduced power output causes one or more DVD players of the entertainment systems  18  to store playback information to memory prior to shutting down. In some embodiments, the input accessory lead  328  comprises a fuse  335 .  
      With reference again to  FIG. 20 , in some embodiments, the electrical line  432   c  couples pins  436   c  of the adapter  312 . Accordingly, in some preferred embodiments, the electrical line  432   c  provides a common ground among entertainment systems  18  coupled to the adapter  312 . In other embodiments, each entertainment system  18  is grounded separately.  
      In some embodiments, one or more secondary adapter cables  318  can comprise one or more branches of communication lines  430 . The communication lines  430  thus can be coupled at one end with a signal source, such as, for example, a signal source selection unit, a DVD player, a television tuner, etc. Branches of the one or more communication lines  430  can be routed through the primary adapter cables  314  and coupled with the adapter connectors  313 . The entertainment systems  18  can communicate with the communication lines  430 , thereby providing additional viewing and/or listening options to users of the systems  18 .  
      In certain embodiments, the junction  316  comprises a seal for joining the primary adapter cables  314  and the secondary adapter cable  318 . In some embodiments, the seal comprises a molded dielectric material, such as polyvinylchloride, that is heat sealed around the primary cables  314  and the secondary cable  318 .  
      As illustrated in  FIG. 21 , in some embodiments, a retainer or retention device  440  secures the entertainment system connector  311  (see, e.g.,  FIG. 24 ) and the adapter connector  313  (see, e.g.,  FIG. 24 ) in a coupled configuration. In certain embodiments, the retention device  440  is removable, providing ready access to the connectors  311 ,  313 . In some embodiments, the retention device  440  comprises a first housing member  441  and a second housing member  442  that substantially surround the entertainment system connector  311  and the adapter connector  313  when the connectors  311 ,  313  are coupled. In some embodiments, the retention device  440  substantially encloses and/or encapsulates the connectors  311 ,  313 . Accordingly, in some instances, the retention device  440  can protect the connectors  311 ,  313  from, for example, dust accumulation, humidity, and/or spilled liquids.  
      In some embodiments, as illustrated, an exterior surface of the retention device  440  is generally cylindrical when the device  440  is closed. The exterior surface can assume any shape, although generally cylindrical configurations are preferred for use with circularly symmetric cables  310 ,  314  and/or circularly symmetric connectors  311 ,  313 . In some embodiments, the retention device  440  comprises a single piece of material, such as molded plastic. In other embodiments, two or more pieces can be joined to form the device  440 .  
      In certain embodiments, the first and second housing members  441 ,  442  cooperate to form a cavity  463  (see, e.g.,  FIGS. 23A and 23B ). In many embodiments, the cavity is sized and configured to accept the connectors  311 ,  313 . In some embodiments, the cavity is sized and configured to only accept the connectors  311 ,  313  when the connectors are coupled with each other. For example, the cavity can comprise an axial length that is substantially equal to the axial length of the connectors  311 ,  313  in a coupled configuration.  
      In preferred embodiments, the retention device  440  comprises one or more releasable locks or fasteners  443  that allow the device  440  to be selectively opened and closed. In the illustrated embodiment, the device  440  comprises two fasteners  443 . Each fastener  443  comprises a clip extension  444  and a clip aperture  445  that cooperate to allow the selective opening and closing of the device  440 , as more fully described below. In various embodiments, the fastener  443  can comprise a clip, clasp, clamp, magnet, hook, hook-and-pile fabric, or other suitable mechanism for maintaining the device  440  in a closed state. In certain embodiments, the fastener  443  is integrally formed with the device  440 , and in other embodiments, it is secured to or around the device  440 .  
       FIG. 22  illustrates one embodiment of the retention device  440  in an open configuration. As shown, the clip extensions  444  are disengaged from the clip apertures  445 . In certain preferred embodiments, the retention device  440  comprises a hinge  446  that connects the first and second housing members  441 ,  442  and allows the housing members  441 ,  442  to move relative to one another. As illustrated, the hinge  446  can be integrally formed with the first and second housing members  441 ,  442 . In other arrangements, the hinge  446  comprises one or more pieces attached to the first and second housing members  441 ,  442 . In some configurations, one or more fasteners  443  are used in place of a hinge  446 .  
      In some arrangements, the first housing member  441  comprises one or more protrusions  447  and the second housing member  442  comprises one or more recesses  448 . The recesses  448  can be configured to accept the protrusions  447  when the device  440  is closed, thereby encouraging alignment of the first and second housing members  441 ,  442 . In the illustrated embodiment, the protrusions  447  are substantially cylindrical with rounded edges. The recesses  448  are also substantially cylindrical, having a diameter slightly larger than that of the protrusions  447 . The relative sizes of the protrusions  447  and recesses  448  can be altered to achieve a tighter or looser fit. A wide variety of arrangements are possible for the protrusions  447  and recesses  448 .  
      In the illustrated embodiment, the protrusions  447  and recesses  448  are spaced away from the hinge  446 . Additionally, one protrusion  447  and recess  448  pair is located adjacent a proximal end  452  of the device  440 , and another protrusion  447  and recess  448  pair is located adjacent a distal end  454  of the device  440 . As used herein, the terms proximal and distal refer to spatial orientation with respect to the entertainment system  18 . Other arrangements of protrusion  447  and recess  448  pairs are possible.  
      In some configurations, the first housing member  441  comprises one or more first extensions, inward projections, interference surfaces, or ridges  461  and the second housing member  442  comprises one or more second extensions, inward projections, interference surfaces, or ridges  462 . In certain configurations, the first and second ridges  461 ,  462  extend inward from a surface of the first and second housing members  441 ,  442 , respectively. As illustrated, in some configurations, the first and second ridges  461 ,  462  extend inward along an entire length of an interior surface of the first and second housing members  441 ,  442 , respectively. In certain configurations, the first and second ridges  461 ,  462  are substantially C-shaped, as shown. In some embodiments, the first and second ridges  461 ,  462  are substantially orthogonal to the surfaces of the housing members  441 ,  442  from which the ridges extend.  
       FIG. 23A  illustrates an end-on view of the distal end  454  of one embodiment of the retention device  440  in a closed configuration. In some embodiments, the first ridge  461  a cooperates with the second ridge  462   a  to define an opening  464   a  when the device  440  is closed. In certain configurations, the opening  464   a  is smaller in at least one dimension than a cross-section of the retention device  440 . For example, in the illustrated embodiment, the opening  464  is generally circular, and the diameter of the circular opening  464   a  is smaller than the diameter of the circular cross-section of an exterior surface  465  of the closed device  440 . Similarly, the first ridges  461   b - f  and the corresponding second ridges  462   b - f  (shown in  FIG. 22 ) of the illustrated embodiment define circular openings  464   b - f  (not shown) of varying diameters when the device  440  is closed. As described below, the diameter of each circular opening  464  so formed can assume various sizes depending on the purpose of the opening  464 .  
      As illustrated in  FIG. 23B , in some embodiments, the cross-section of the opening  464   a  partially defined by the first and second ridges  461   a ,  462   a  is noncircular. For example, in certain cylindrical configurations, the ridges  461   a  and  462   a  extend only along a partial length of a surface of the first and second housing members  441 ,  442 , respectively. In certain of such configurations, the opening  464   a  defined by the ridges  461   a  and  462   a  when the device  440  is closed has a measurement in one dimension equal to the diameter of the circular cross-section of an interior surface  466  of the closed device  440 , and a measurement in another dimension smaller than the cross-sectional diameter of the interior surface  466 . Various other opening configurations can be used, although circular openings are preferred for use with circularly symmetric cables and circularly symmetric connectors.  
      With continued reference to  FIGS. 23A and 23B , in certain embodiments, the clip extension  444  comprises an arm portion  466  and a tip portion  467 . The tip portion  467  can comprise a face  468  and a ledge  469 . In certain embodiments the face  467  is angled such that when the device  440  is being closed, the clip aperture  445  forces the tip portion  467  inward toward the device  440 . As a result, the arm portion  446  is bent, giving rise to a restoring force that eventually seats the ledge  469  under the clip aperture  445  when the device  440  is closed. A top surface of the ledge  469  abuts a bottom surface of the clip aperture  445 , thereby retaining the device  440  in a closed position. To open the device  440 , the tip portion  467  is depressed toward the device  440  until the top surface of the ledge  469  no longer contacts the bottom surface of the clip aperture  445 . In some instances, an upward force is applied to the tip portion  467  to encourage it through the clip aperture  445 . In other instances, the device  440  is biased toward opening such that no upward force need be applied to the tip portion  467  to encourage it through the clip aperture  445 .  
       FIG. 24  illustrates one embodiment of a retention device  440  in an open configuration located alongside a coupled adapter connector  313  and entertainment system connector  311 . As described above, in certain embodiments, the ridges  461  and  462  cooperate to form openings  464  when the device is closed. In general, the openings  464  can encourage alignment of the connectors  311 ,  313 . In some embodiments, the openings  464  are sized to allow the passage therethrough of a cable (e.g., the cable  310  or the cable  314 ), but prevent the passage therethrough of a connector (e.g., the entertainment system connector  311  or the adapter connector  313 ). In other embodiments, the openings  464  are sized to prevent the passage therethrough of the cable as well. For example, the openings  464  can be sized smaller than a thickness of the cable. In certain embodiments, the ridges  461 ,  462  comprise a material having a high coefficient of friction with respect to a casing of the cable to aid in preventing the movement of the cable. In some embodiments, the casing comprises rubber and the ridges  461 ,  462  comprise molded plastic. In some embodiments, the ridges  461  and  462  comprise a roughened or etched surface.  
      In certain embodiments, the adapter connector  313  comprises one or more extensions, projections, or interference surfaces  472  that extend outward from a center of the connector  313 . In the illustrated embodiment, the adapter connector  313  comprises two extensions  472   a ,  472   b . The extensions  472   a ,  472   b  comprise distal and proximal faces, respectively, of the adapter connector  313 . Each extension  472   a ,  472   b  extends substantially perpendicularly from an axial center of the connector  313 . In certain embodiments, the entertainment system connector comprises one or more extensions  474  that extend outward from a center of the connector  311 . In the illustrated embodiment, each extension  474   a ,  474   b , and  474   c  extends substantially perpendicularly from an axial center of the connector  311 .  
      In some embodiments, the opening  464   b  formed by the ridges  461   b  and  462   b  when the device  440  is closed is smaller in at least one dimension than the extension  472   a . In certain of such embodiments, the opening  464   d  formed by the ridges  461   d  and  462   d  is smaller in at least one dimension than the extension  474   a , and/or the opening  464   e  formed by the ridges  461   e  and  462   e  is smaller in at least one dimension than the extension  474   c . In such configurations, the ridges  461   b,d,e  and  462   b,d,e  can operate to prevent the separation of the coupled connectors  311 ,  313 . For example, in certain embodiments, as axial forces are applied to the cables  310 ,  314  in a manner that would separate the connectors  311 ,  313 , the extension  472   a  contacts one or more of the ridges  461   b  and  462   b . Similarly, the extension  474   c  contacts one or more of the ridges  461   e  and  462   e . Accordingly, the ridges  461   b,e  and  462   b,e  cooperate with the extensions  472   a  and  474   c  to prevent the connectors  311 ,  313  from moving away from each other, e.g., interference surfaces cooperate to prevent axial movement of the connectors  311 ,  313  relative to each other. In some embodiments, additional interference surfaces cooperate with each other to prevent relative movement between the connectors  311 ,  313 . For example, in some embodiments, the ridges  461   d  and  462   d  cooperate with the extension  474   a  to prevent the connector  311  from moving axially with respect to the connector  313 . In further embodiments, one or more of the openings  464   a,b,e,f  through which the cables  310 ,  314  can extend are smaller than the cables  310 ,  314 , which further serves to prevent separation of the connectors  311 ,  313 .  
      In some embodiments, the retention device  440  comprises one or more surfaces, or interference surfaces, configured to prevent the connectors  311 ,  313  from moving laterally relative to each other. In the illustrated embodiment, the device  440  comprises interior surfaces  481  and  482 . In some embodiments, the interior surfaces  481 ,  482  comprise one substantially continuous surface when the device  440  is closed. In some embodiments, the interior surfaces  481 ,  482  contact an exterior surface  483  of the connector  313  when the device is closed  440 . In certain of such embodiments, the interior surfaces  481 ,  482  cooperate with the exterior surface  483  to substantially prevent the connector  313  from moving in a transverse or lateral direction relative to the connector  311 . For the illustrated case of a circularly symmetrical connector  313 , the transverse or lateral direction can be, for example, any radial direction. In certain embodiments, contact between the interior surfaces  481 ,  482  and the exterior surface  483  along an axial length of the connector  311  maintains a longitudinal axis of the connector  311  aligned with a longitudinal axis of the device  440  and prevents radial movement of the connector  311  relative to the connector  313 . Similarly, in some embodiments, contact between interior surfaces  484 ,  485  and  486 ,  487  of the device  440  and exterior surfaces  488 ,  489  of portions of the connector  313 , respectively, maintains a longitudinal axis of the connector  313  aligned with a longitudinal axis of the device  440  and prevents radial movement of the connector  313  relative to the connector  311 .  
      In further embodiments, the retention device  440  can comprise interference surfaces, such as the surfaces  481 - 484 , that prevent rotational movement of the connectors  311 ,  313  relative to each other, such as by friction (as described below). In many embodiments, some interference surfaces of the device  440  are configured to prevent or inhibit multiple forms of relative movement between the connectors  311 ,  313 .  
      In some embodiments, an interior surface of the retention device  440  is smaller than an exterior surface of one or more of the connectors  311 ,  313 . In such embodiments, friction can arise between one or more of the connectors  311 ,  313  and the device  440  when the device  440  is closed, thereby helping to secure or securing the connectors  311 ,  313  in a coupled configuration. In certain of such embodiments, the interior surface of the device  440  is coated with a high-friction material, is roughened, or is etched, thereby increasing the friction. Furthermore, in such embodiments, the retention device  440  can be placed in tension when the device  440  is closed, thereby creating a bias towards being in an open configuration. As discussed above, such a bias can aid in opening the device  440  when the clip configuration of the illustrated embodiment is employed.  
      The retention device  440  can provide various advantages over conventional methods, such as the use of electrical tape, for securing connectors to one another. As discussed above, the retention device  440  can apply normal and frictional forces to the connectors  311 ,  313 . These forces can often be stronger than the forces supplied by electrical tape, thereby ensuring a more reliable coupling of the connectors. The use of a retention device  440  also facilitates replacement of an entertainment system  18 , if needed. Whereas removing electrical tape can be time consuming, removal of the retention device  440  is relatively quick.  
      Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics of any embodiment described above may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.  
      Similarly, it should be appreciated that in the above description of embodiments, various features of the inventions are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.