Abstract:
A headrest provided with several loudspeakers which normally reproduce an ambiophonic sound experience. The headrest generally includes a central section provided with at least one loudspeaker, one side section provided with at least one loudspeaker and a second side section provided with at least one loudspeaker. The side sections are arranged on either side of the center section, and extend substantially perpendicularly towards the top relative to the center section. The headrest is arranged in a way so it can be connected to an audio signal source capable of generating several different audio signals.

Description:
REFERENCE TO PARENT APPLICATIONS 
       [0001]    This patent application claims priority from Canadian patent application n° 2,639,409, titled “Home theater cushion”, filed Sep. 9, 2008 at the Canadian Intellectual Property Office. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates essentially to the field of ambiophonics and “home theater” systems. The present invention also relates to the field of headrests and cushions which include loudspeakers. 
       BACKGROUND OF THE INVENTION 
       [0003]    The purpose of a home theatre system is to reproduce a sound environment similar to that of a movie theater, that is to say, to reproduce a sense of depth due to the way the sounds are emitted. There are a number of techniques to achieve this result. These techniques are based on the presence of several loudspeakers placed around the room. 
         [0004]    Notations such as “2.1”, “5.1”, “6.1”, “7.1” identify the number of loudspeakers used to reproduce the audio sequence. A “7.1” system, describes an eight channel sound reproduction system, of seven loudspeakers and bass and sub-bass loudspeaker commonly known as a “subwoofer” (the “.1”). The seven loudspeakers are arranged as follows: the two front loudspeakers are used to produce ambient sound and music, the center loudspeaker, placed front is used to produce dialogue, the two side loudspeakers and the two rear loudspeakers are used to produce ambiophonic sound effects (“surround sound”). Meanwhile, the subwoofer is used to produce bass and sub-bass sound. A Dolby™ Surround 7.1 system is an example of this type of home theater system. 
         [0005]    The home theater system normally includes an amplifier (Stereo, Dolby™ Digital, LC Concept, Digital Theater System (DTS), Sony Dynamic Digital Sound (SDDS), Dolby™ Pro Logic, Dolby™ Pro Logic 2, etc.). The image source may be, for example, a digital television satellite receiver, a digital terrestrial television (“DTT”) receiver, Video Cassette Player (VHS (Video Home System), SVHS (Super VHS) or digital hard disk drive, etc.), a CD player (Compact Disc), a DVD player (Digital Video Disc) (standard, Blu-ray, etc.) DIVX™ player, a multimedia personal computer or HTPC (Home Theater Personal Computer), a high definition movie player, game console, etc. 
         [0006]    Images can be displayed on an HDTV, plasma screen, LCD (Liquid Crystal Display) screen, video projector, rear projection screen, etc. 
         [0007]    Various technologies have been developed over the years to produce a home theater sound environment. 
         [0008]    Dolby™ Surround Prologic (“DPL”) processing technology was invented by Jim Fosgate then sold to Dolby™ Laboratories. This was the first processing technology to give real depth to the soundscape. Sound is split into four channels: front left, center, right front and two back surround speakers, one left and one right, the surround speakers are identical. 
         [0009]    The Dolby™ Digital (“DD”) processing technology was invented by Dolby™ Laboratories. This processing technology splits the sound into six channels (5+1): front left, center, front right, back left, back right and a channel for the sub-bass (to a subwoofer). The rear channels, or surrounds, are different and reproduce the entire sound spectrum. 
         [0010]    The Digital Theater System (“DTS”) technology from Digital Theater Systems Inc., distributes the sound via six channels (5+1) the same as Dolby™ Digital, but the sound is less compressed and digital processing is different. 
         [0011]    Dolby™ Surround Prologic I (“DPL-1”) is an improved version of Dolby™ Surround. Four channels are recreated from a stereo source. A center channel is added. DPL-I limits high frequencies in the surround channel to 9,000 hertz. 
         [0012]    Dolby™ Surround Prologic II (“DPL-II”) processing technology was invented by Jim Fosgate then sold to Dolby™ Laboratories. This processing technology uses the same principles as DD and DTS but with different signal processing (two channels only). 
         [0013]    Dolby™ Surround processing technology extracts three channels from two stereo channels: the front right, front left and rear surround channel are split across two loudspeakers which reproduce the same sound. 
         [0014]    Dolby™ Surround Prologic II technology provides two additional channels to Dolby™ Surround Prologic: two different surround channels and a subwoofer channel. In addition to this, the surround channels broadcast the entire bandwidth, with no limitation at high frequencies. 
         [0015]    Dolby™ Digital and DTS are developed by different laboratories and do not use the same algorithms or the same compression ratios. DTS uses a lower compression ratio than Dolby™ Digital. 
         [0016]    Other formats have emerged alongside high definition (HD) technology, such as Dolby™ Digital Plus and DTS HD. 
         [0017]    All the loudspeakers mentioned above serve a specific purpose. The two front loudspeakers reproduce the music and ambient sound, the center loudspeaker is for dialogue and the two surround (or lateral) loudspeakers give the effect of depth. 
         [0018]    When five loudspeakers and a subwoofer are used (in the “5.1” version), Dolby™ Laboratories suggest that the back loudspeakers (left and right) are directed towards the listening position. In theory, the subwoofer can be placed anywhere, as the sub-bass sound waves it produces cannot be located by the human ear. 
         [0019]    Technologies using seven loudspeakers and a subwoofer involve a doubling of the back center channel. These back center channels correspond to the two “back surround” outputs, the back left and right loudspeakers are simply the left and right “surround” positions. 
         [0020]    Despite technological advances in the field of home theater systems, the fact remains that these systems generally require a room of adequate size to be able to position the loudspeakers correctly, a room that is not always available. Moreover, for current home theater systems, it is usually necessary to adjust the sound to quite a high level to reproduce all sound effects. However, the noise level required can become annoying when the room in which the system is installed is close to the neighbors. A new system mitigating these disadvantages would therefore be useful. 
       SUMMARY OF THE INVENTION 
       [0021]    The present invention provides a headrest comprising a number of loudspeakers capable of reproducing a home theater environment. 
         [0022]    The ambiophonic headrest can be installed on a chair, a bed, or on a wall. 
         [0023]    The ambiophonic headrest includes at least three and preferably up to eight loudspeakers and a subwoofer or sub-bass loudspeaker. The headrest can reproduce a surround sound environment as generated by a stereo system, Dolby™ 5.1, Dolby™ 6.1 or Dolby™ 7.1 systems, or systems using multiple loudspeakers to produce a sound effect. 
         [0024]    The ambiophonic headrest can include more loudspeakers, or be adapted to a technology other than Dolby™ to reproduce a sound environment. 
         [0025]    The ambiophonic headrest allows the user to benefit fully from the capabilities of home theater systems without disturbing their neighbors. 
         [0026]    By preference the ambiophonic headrest is portable to allow its user to use it in different locations and/or with different systems (eg. home theater system, games console, computer, etc.). 
         [0027]    The features of the present invention which are considered new and inventive will be described in greater detail in the claims set out below. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0028]    The benefits, objectives and features of the present invention will be more easily observed by referring to the following detailed description to be made using diagrams in which: 
           [0029]      FIG. 1  is a representation of a Dolby™ Digital 5.1 system. 
           [0030]      FIG. 2  is a representation of a Dolby™ Digital 6.1 system. 
           [0031]      FIG. 3  is a representation of a Dolby™ Digital 7.1 system. 
           [0032]      FIG. 4A  is an extended schematic view of an ambiophonic headrest. 
           [0033]      FIG. 4B  is a top view showing the arrangement of the loudspeakers in the extensions of the ambiophonic headrest from  FIG. 4A . 
           [0034]      FIG. 5  is an isometric view of a first embodiment of the ambiophonic headrest. 
           [0035]      FIG. 6  is another isometric view of the embodiment shown in  FIG. 5 . 
           [0036]      FIG. 7  is a sectional view of the embodiment shown in  FIG. 5 . 
           [0037]      FIG. 8  is a top view of the embodiment shown in  FIG. 5 . 
           [0038]      FIG. 9  is an isometric view of the embodiment shown in  FIG. 5 , which has an upper piece installed. 
           [0039]      FIG. 10  is an isometric view of the embodiment shown in  FIG. 8 , the headrest loudspeakers are covered with a grill. 
           [0040]      FIG. 11A  is an isometric view of the embodiment shown in  FIG. 5 , with a strap. 
           [0041]      FIG. 11B  is an isometric view of the embodiment shown in  FIG. 5 , with a protective cover. 
           [0042]      FIG. 12  is an isometric view of a second embodiment of the ambiophonic headrest. 
           [0043]      FIG. 13  is a side view of a support for the ambiophonic headrest. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0044]    An ambiophonic headrest is described below. Although the invention will be described using examples of one or more preferred embodiments, it is important to understand that these preferred embodiments are used to illustrate the invention and not to limit its scope. 
         [0045]      FIGS. 1-3  show the loudspeaker arrangement for Dolby™ Digital 5.1, 6.1 and 7.1 installations respectively. The loudspeakers are positioned on either side of the listening position  102 . The user is sitting in front of the image produced by a television  150  (or other image projection system). The subwoofer  104  has no preferred position and is placed to the front left side for illustrative purposes. 
         [0046]    The installation of a 5.1 system shown in  FIG. 1  includes a front left loudspeaker  108 , a right front loudspeaker  110 , a center loudspeaker  106  placed at the front, a left side loudspeaker  112  and a right side loudspeaker  114 . 
         [0047]    Installation of a 6.1 system shown in  FIG. 2  includes the same loudspeakers as those of the 5.1 system with the addition of a back loudspeaker  116 . The installation of a 7.1 system also includes the same loudspeakers as those of the 5.1 system, with the addition of a back left loudspeaker  118  and a back right loudspeaker  120 . 
         [0048]    As shown in  FIGS. 4A ,  5 ,  6  and  8 , a preferred embodiment of the ambiophonic headrest  200  by preference includes eight loudspeakers, a back right loudspeaker  220 , a back left loudspeaker  218 , a right side loudspeaker  214 , a left side loudspeaker  212 , a front right loudspeaker  210 , a front left loudspeaker  208 , a center right loudspeaker  205 , a center left loudspeaker  207  and a subwoofer  204 . It should be noted that the signal normally intended for the center loudspeaker is split and sent to the center right  205  and left  207  loudspeakers. These center right and left loudspeakers  205  and  207  therefore reproduce the same audio signal. 
         [0049]    The headrest  200  normally includes a back panel, or central portion,  230  to support the user&#39;s head  202  and to which the right  220  and left  218  back loudspeakers and preferably the subwoofer  204  are fixed to. The headrest  200  includes an extension or right side section  232  and an extension or left side section  234  where the side, front and center loudspeakers are placed. The left  234  and right  232  extensions come out from the sides of the back panel  230  preferably at right angles but it is possible that these extensions can be at an angle smaller or greater than 90° from the back panel. The left  234  and right  232  extensions can be mounted on the back panel  230  or can be made as an integral part of the back panel  230 . 
         [0050]    When a user uses the headrest  200 , he rests its head on the central section  230 . The distance between the right  234  and left  232  extensions is generally arranged to receive the head of a user and leave a space between the head of the user and the internal walls of the left  234  and right  232  extensions (see  FIG. 4B ). 
         [0051]      FIGS. 4B and 7  show the preferred arrangement of loudspeakers in the left and right extensions. The loudspeakers are arranged symmetrically on both sides, the arrangement will be explained for one side only for purposes of simplification. As shown in the Figures, the loudspeakers placed in the right extension  232  are not all at the same level. In particular, the side right loudspeaker  214  is closer to the back panel  230 , which is lower than the center right loudspeaker  205  and the front right loudspeaker  210 . There is therefore a distance  244  between axes  240  and  242  through the center of the right loudspeakers  214  and the side right loudspeaker  205  and the front right loudspeaker  210 . 
         [0052]    The distance  244  between the loudspeakers is important to reproduce the effect of depth. As discussed in the description of  FIGS. 1 to 3 , the back loudspeakers are normally placed behind the listening position. On the headrest, side loudspeakers  212  and  214  are positioned laterally and behind the user&#39;s ears on the inner wall of extensions  232  and  234 . The direction of the sound produced by loudspeakers  212  and  214  is normally parallel to the direction of axes  240  and  242 . 
         [0053]    The front left loudspeakers  208  and  210  are positioned before the user&#39;s ears. The center right and left loudspeakers  205  and  207  are the same; they are arranged before the user  202  as in a home theater setup. As already mentioned, the center right and left loudspeakers  205  and  207 , both reproduce the sound usually produced by the center loudspeaker  106  (see  FIGS. 1-3 ). 
         [0054]    The back left loudspeakers  218  and  220  are located behind the user, on the back panel  230 . The sound is sent more or less perpendicular to the surface of the back panel  230 . 
         [0055]    The subwoofer (or bass and sub-bass loudspeaker)  204  is placed in the back panel  230 . It should be noted that the subwoofer  204  can be placed in a different position to the one shown, either on the back panel  230  or on the left  234  or right  232  extensions. However, the subwoofer  204  is preferably placed on the back panel  230  so as to be located behind the head of the user  202 . In doing so, the user  202  can feel the vibrations produced by the subwoofer  204 , adding an extra dimension to the listening and/or viewing experience. It should also be noted that subwoofer  204  may be placed more deeply into the back panel  230  than the back loudspeakers  218  and  220 . 
         [0056]    It should be noted that the loudspeakers can be arranged on a specific angle to change the direction of the sound. 
         [0057]    The back panel  230  and the right  232  and left  234  extensions are usually made of polymeric foam and are preferably coated with a polymeric or elastomeric membrane so as to contain the sound within the headrest  200 . Moreover, the loudspeakers are preferably covered with a grid  270 , shown in  FIG. 10 , or some similar form of protection to protect them during use. 
         [0058]    The ambiophonic headrest  200  in its entirety is preferably covered with a cover covering the back panel  230  and the right  232  and left  234  extensions. The cover is preferably removable and made of a washable material. 
         [0059]    As shown in  FIGS. 9 and 10 , the headrest can be provided with additional removable extensions such as the extension  260  mounted behind the central panel  230  between the left  232  and right  234  extensions. Extension  260  allows, among other things, better containment of the sound from the loudspeakers. Additional extensions such as extension  260  are typically attached to the headrest  200  by Velcro® strips or other means of attachment. 
         [0060]    The headrest can be suspended for storage or during use, from a wall hook using a strap  280  as shown in  FIG. 11  or from an adjustable stand  400  as illustrated in  FIG. 13 . Strap  280  may also allow the cushion to be fixed to the back of an armchair or a chair. A protective cover  282  attached to the back of the ambiophonic headrest  200  can be used to install it to a chair or armchair. 
         [0061]    The adjustable support  400  illustrated in  FIG. 13  normally includes a base  402  which is fixed to a telescopic support rod  404 . A pivoting arm  408  is mounted to the telescopic support rod  404  by a lockable hinge  406 . Arm  408  is provided with a plate  410  (or other means of support) at one end, which can support the headrest  200 . 
         [0062]    In general, back panel  230  is made of a material such as foam to provide comfort to the user when listening to a visual sequence. The material may be fairly rigid or be offered in a variety of hardnesses to meet the needs of different users. The padding can be made of polymeric foam. 
         [0063]    Extensions  232  and  234  may be made of the same material as the back panel if this adequately supports the loudspeakers and maintains the shape of the ambiophonic headrest  200 . The extensions may also be made of a stiffer material to keep the shape of the ambiophonic headrest. 
         [0064]    Although not shown in the Figures, the headrest  200  may be improved by the addition of a rigid skeleton where necessary to support the loudspeakers. 
         [0065]    Note that the ambiophonic headrest can be made in many shapes although they have not been illustrated in the present invention. For example, the headrest  300 , shown in  FIG. 12 , is egg-shaped. 
         [0066]    The person skilled in the art would understand that the loudspeakers  204  to  220  are adapted to be connected in a conventional manner, either by wires, or by a wireless interface (e.g. using a “Bluetooth” or “Wi-Fi” interface), to an audio signal source such as an amplifier connected to a DVD player or a digital receiver. Moreover, the person skilled in the art would understand that if only some of the loudspeakers are connected to an audio signal source, only some of the loudspeakers will produce sound. For example, if the preferred embodiment of the headrest  200  is connected to a Dolby™ 5.1 audio source, the side right  214  and left  212  loudspeakers will produce no sound. 
         [0067]    Finally, the person skilled in the art would understand that the loudspeakers should normally be chosen so that they can be integrated into the back panel  230  and to the extensions  232  and  234 . 
         [0068]    Although it has been described using one or more preferred embodiments, it should be understood that the present invention can be used, employed and/or embodied in a multitude of other forms. Therefore, the following claims should be interpreted to include these forms while remaining outside the limits set by prior art.