Abstract:
Disclosed is a wireless surround sound speaker system wherein a transmitter broadcasts a variety of FM signals that correspond to the individual speaker channels commonly found in a surround sound system. Receivers, individually equipped with signal receiving, conditioning and amplification components, are configured to receive any one of the broadcast signals in a remote location and are used to drive a conventional loudspeaker in that location. Powered by wall socket or via DC battery packs, the receivers, used in conjunction with the transmitter, provide surround sound capabilities without the need for complex and difficult wiring.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to wireless speaker systems and more specifically to a wireless surround sound speaker system in which a transmitting unit transmits separate and distinct signals for all of the various output channels requisite of surround sound processing. 
     2. Description of the Related Art 
     Home theater entertainment systems are becoming increasingly sophisticated and complex. Typical surround sound systems incorporate at least five speakers: front right and left speakers, rear right and left speakers and a front center speaker, requiring that a number of loudspeakers be placed throughout the viewing room, on all sides of the listener/viewer, in order to achieve the desired audio effects. In fact, in some home theater systems, speakers are also placed throughout the entire house in order to broadcast music to every room when the theater effects are not in use. As a result, a multitude of speaker wires must be run throughout the room and the house to each speaker which can be extremely difficult to accomplish. Also, the fact that there is an individual channel associated with each of the surround sound speakers that makes attaching a speaker wire to the correct receiver output channel and speaker equally troublesome. Accordingly, there is a need for a means by which the surround sound speakers can be placed and used throughout a room, or even an entire home, while avoiding the burdens associated with wiring such speakers and adjusting their channel selection and equalization settings. The development of the present invention fulfills this need. To accomplish this, switchable receiving units are tuned to a desired transmitter output channel and include an integrated amplifier, signal biasing capabilities and a graphic equalizer for adjusting the tonal characteristics of the individual speaker to which it is connected, thereby allowing use of the present invention interchangeably with existing loudspeaker arrangements and adjusted at a remote location. 
     A search of the prior art did not disclose any patents that read directly on the claims of the instant invention. However, several references disclose wireless speaker systems in which FM or infrared signals are transmitted to speakers that are equipped with signal receiving and amplification electronics that are used to drive the loudspeakers. While many of these inventions touch upon the principles of surround sound processing and wireless signal transmission, none of these devices include any individualized channel selection or equalization features that allow the speakers to be used interchangeably and therefore neither anticipate nor disclose any embodiment that would preclude its novelty and the utilitarian functionality of the present invention: 
     U.S. Pat. No. 5,708,718, issued in the name of Ambourn et al.; 
     U.S. Pat. No. 5,666,658, issued in the name of Borchardt et al.; 
     U.S. Pat. No. 5,666,422, issued in the name of Harrison et al.; 
     U.S. Pat. No. 5,673,323, issued in the name of Schotz et al.; 
     U.S. Pat. No. 5,218,641, issued in the name of Abe et al.; 
     U.S. Pat. No. 4,899,388, issued in the name of Mlodzikowski et al.; and 
     U.S. Pat. No. 3,590,382, issued in the name of Kenney. 
     The &#39;718 patent, issued in the name of Ambourn et al., discloses a surround sound processor system in which an audio signal is decoded into in-phase and out-of-phase components. The in-phase signals are sent via FM transmitter to a receiver component that is connected to an amplifier that boosts the signal, driving the center channel loudspeaker(s). The out-of-phase signals are sent via FM transmitter to a receiver component that is connected to an amplifier that boosts the signal, driving the rear channel loudspeaker(s). This disclosure differs from the present invention in that the receiver/amplifier portions are not integrated into the speaker design which necessitates further wiring in the remote location. Furthermore, the &#39;718 invention requires the use of external wiring connections between the receiver/amplifier combination, making likely the occurrence of the problems to which the present invention is directed. 
     The &#39;658 patent, issued in the name of Borchardt et al., discloses a wireless signal transmission system wherein an audio signal is via FM transmission to a pair of wireless headphones. The disclosure neither discloses nor anticipates any surround sound applications utilizing loudspeakers with integrated signal receiving, amplification channel selection and graphic equalization capabilities. 
     The &#39;422 patent, issued in the name of Harrison et al., discloses a remote speaker arrangement for surround sound applications intended to eliminate the need for front channel speakers. The wireless rear speakers are used to create “phantom” front speakers by combining a bipolar rear speaker with a mono front speaker. This arrangement, however, requires that the speakers be wired to a combination receiver/amplifier in the remote location and therefore suffers from the drawbacks that the present invention solves. The disclosure neither discloses nor anticipates any surround sound applications utilizing loudspeakers with integrated signal receiving, amplification channel selection and graphic equalization capabilities. 
     The &#39;323 patent, issued in the name of Schotz et al., discloses an analog spread spectrum wireless speaker system intended to allow the user to place a pair of speakers at a remote location without the need to run speaker wires. The &#39;641 patent, issued in the name of Abe et al., discloses a wireless receiver for use with headphones or loudspeakers. The device consists of a transmitter that transmits infrared radiation signals, modulated by an audio signal, to an infrared receiver that translated the signal to an audio signal and amplifies it for use with headphones or loudspeakers at a remote location. These disclosures differ from the present invention in that the receiver/amplifier portions are not integrated into the speaker design which necessitates further wiring in the remote location. Furthermore, the disclosures neither disclose nor anticipate any surround sound applications utilizing loudspeakers with integrated signal receiving, amplification channel selection and graphic equalization capabilities. 
     U.S. Pat. No. 4,899,388, issued in the name of Mlodzikowski et al., discloses an infrared speaker system in which a pair of remotely located speakers are fit individually with an infrared receiver and an audio amplifier. An infrared transmitter connected to a stereo or the like converts both left and right channel audio signals to an infrared signal and sends them to the speakers. Each speaker receiver is equipped with a filter that selects the appropriate channel, left or right, converts it to an audio signal and amplifies it, driving the loudspeaker. The &#39;382 patent, issued in the name of Kenney, discloses a remote speaker system similar in nature to that of the &#39;388 disclosure, the main difference being that an infrared signal rather than an FM signal is used to transmit the audio signal. While these disclosures do anticipate individual reception and amplification components in each speaker, the speakers are still limited to a single, non-selectable channel. Furthermore, the disclosures neither disclose nor anticipate any surround sound applications utilizing loudspeakers with integrated signal receiving, amplification channel selection and graphic equalization capabilities. 
     While several features exhibited within these references may be incorporated into this invention, alone and in combination with other elements, the present invention is sufficiently different so as to make it distinguishable over the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention consists of a system uses a transmitting unit that emits a low level FM signal for each of the surround sound speaker channels. The transmitting unit incorporates surround sound processing circuitry that in which the user can select the desired effect to apply to the signals, from large concert hall to intimate club settings, along with conventional front-rear biasing, right-left biasing and graphic equalization capabilities. Individual receiving units, powered either by DC battery supply or conventional AC wall socket, are used to receive the transmitted signal and drive existing loudspeaker arrangements. The receiving unit includes electronic components that receive the respective speaker channel signal, convert it to an audio signal and amplifies it in order to drive the loudspeaker. Each receiving unit is fit with a channel selection switch that allows it to be configured to receive and amplify any of the surround sound channel signals transmitted by the transmitting unit. Furthermore, each receiving unit includes individual left-right biasing, front-rear biasing and graphic equalization and volume adjustment capabilities that can be enabled and used in the remote location, defeating the settings of the transmitting unit in the scenario where users in different locations or rooms are listening to the same selection. 
     It is therefore an object of the present invention to provide a wireless speaker system wherein a transmitting unit and a receiving unit allows the user to place speakers about a room or rooms without running speaker wires from stereo components to each individual speaker assembly. 
     It is another object of the present invention to provide a wireless speaker system in which each receiving unit is fully self sufficient, being powered either a battery powered DC supply or a power cord plugged into a conventional wall socket. 
     It is another object of the present invention to provide a wireless speaker system in which a transmitter unit transmits individual channel signals, in stereo or surround sound, on an FM frequency. 
     It is another object of the present invention to provide a wireless speaker system in which a transmitter unit includes the ability to adjust the settings for the left-right biasing, front-rear biasing, graphic equalization and volume of the transmitted signal(s). 
     It is another object of the present invention to provide a wireless speaker system in which the use of a receiver assembly allows for use of the wireless speaker system with existing loudspeaker arrangements. 
     It is another object of the present invention to provide a wireless speaker system in which each individual receiver assembly can be configured to receive any of the stereo or surround sound signals transmitted by the transmitter unit. 
     Finally, It is an object of the present invention to provide a wireless speaker system in which each receiver assembly allows the user to adjust the individual settings for the left-right biasing, front-rear biasing, graphic equalization and volume of the transmitted signal(s), defeating those of the transmitter unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
     FIG. 1 is a plan view of the wireless surround sound speaker system, according to the preferred embodiment of the present invention; 
     FIG. 2 is a front view of the transmitter component of the wireless surround sound speaker system, according to the preferred embodiment of the present invention; 
     FIG. 3 is an enlarged front view of the control panel of the receiver unit component of the wireless surround sound speaker system, according to the preferred embodiment of the present invention; 
     FIG. 4 is a front view of a conventional loudspeaker used in conjunction with the wireless surround sound speaker system, according to the preferred embodiment of the present invention; 
     FIG. 5 is a block diagram depicting the operation of the transmitter component of the wireless surround sound speaker system, according to the preferred embodiment of the present invention; and 
     FIG. 6 is a block diagram depicting the operation of the receiver unit component of the wireless surround sound speaker system, according to the preferred embodiment of the present invention. 
    
    
     LIST OF REFERENCE NUMBERS 
       10  Speaker System 
       11  Listener 
       12  Television 
       13  Transmitter 
       14  Receiver 
       15  Front-Left Speaker 
       16  Front Right-Speaker 
       17  Center Speaker 
       18  Rear-Left Speaker 
       19  Rear-Right Speaker 
       20  Transmitter Control Panel 
       21  Graphic Equalizer 
       22  Sliding Knobs 
       23  Balance Knob 
       24  Fader Knob 
       25  Volume Knob 
       26  Surround Sound Effects Buttons 
       27  Power Switch 
       30  Loudspeaker 
       31  Speaker 
       32  Receiver Control Panel 
       33  Air Port 
       34  Graphic Equalizer 
       35  Sliding Knobs 
       36  Balance Knob 
       37  Fader Knob 
       38  Volume Knob 
       39  Conditioning Selection Switch 
       40  Channel Selection Knob 
       41  Power Switch 
       42  Power Cord 
       43  Two-Prong Plug 
       50  Home Theater/Stereo System 
       51  Sound Signals 
       52  Left Channel 
       53  Right Channel 
       54  Surround Sound Processor 
       55  In-Phase Sound Signal 
       56  Front-Left Sound Signal 
       57  Front-Right Sound Signal 
       58  Out-Of-Phase Sound Signal 
       59  Rear-Left Sound Signal 
       60  Rear-Right Sound Signal 
       65  In-Phase Transmitter Signal 
       66  Out-Of-Phase Transmitter 
       67  In-Phase Broadcast Signal 
       68  Out-Of-Phase Broadcast Signal 
       70  Signal Level Conditioning Circuitry 
       71  Conditioned In-Phase Sound Signal 
       72  Conditioned Front-Left Sound Signal 
       73  Conditioned Front-Right Sound Signal 
       74  Conditioned Out-Of-Phase Sound Signal 
       75  Conditioned Rear-Left Sound Signal 
       76  Conditioned Rear-Right Sound Signal 
       80  Conditioned In-Phase Transmitter 
       81  Conditioned Out-Of-Phase Transmitter 
       82  Conditioned In-Phase Broadcast Signal 
       83  Conditioned Out-Of-Phase Broadcast Signal 
       90  Conditioned In-Phase Signal Receiver 
       91  Conditioned Out-Of-Phase Signal Receiver 
       92  Conditioned Signal Decoder 
       93  First Selected Conditioned Signal 
       100  In-Phase Signal Receiver 
       101  Out-Of-Phase Signal Receiver 
       102  Unconditioned Signal Decoder 
       103  Selected Signal 
       105  Signal Level Conditioning Circuitry 
       106  Second Selected Conditioned 
       110  Amplifier 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1. Description of the Preferred Embodiment 
     Referring now to FIG. 1, depicted is a plan view of the remote surround sound speaker system, hereinafter speaker system  10 . The speaker system  10  is depicted in this figure in a surround sound home theater application where the listener  11  is viewing a television  12  upon which a motion picture or other program where the listener  11  may desire surround sound effects. The transmitter  13  transmits wireless signals to several receivers  14  that, in turn, are used to drive a front-left speaker  15 , a front right-speaker  16 , a center speaker  17 , a rear-left speaker  18  and a rear-right speaker  19 , broadcasting the appropriate sounds via loudspeakers  30  required to create the desired surround sound effect. As will be described in further detail herein below, the individual receivers  14  are identical in construction and can be configured so as assume the configuration of any of the aforementioned position-specific speakers (front-left, front-right, etc.). Furthermore, each receiver  14  is capable of either remote or local signal level conditioning wherein graphic equalization, balance adjustment, fader adjustment, and volume adjustment are applied to the signal broadcast by the transmitter  13 . 
     Referring now to FIG. 2, depicted is the transmitter  13  that is used in conjunction with the speaker system  10 . The transmitter control panel  20  houses the various controls that allow the user to define the operation of the transmitter  13 . A graphic equalizer  21  allows for the adjustment of the tonal characteristics of the sound, on several bands, by use of individual sliding knobs  22 . A balance knob  23  allows for the adjustment of the sound between the right and left channels. A fader knob  24  allows for the adjustment of the sound between front and rear channels. A volume knob  25  allows for the adjustment of the playing volume. An array of surround sound effects buttons  26  allow for the selection of a variety of surround sound effects to be applied to the broadcast signal. Connected to a conventional home entertainment or stereo system (not shown), the user can select from a variety of effects including normal stereo, concert hall, jazz club, theater, rock and pop. A power switch  27  allows the transmitter  13  to be powered on and off. The function of the controls located on the transmitter control panel  20  as they relate to the operation of the transmitter  13  will be discussed in further detail herein below. 
     Referring now to FIGS. 3 and 4, depicted is a receiver  14  for use in conjunction with the speaker system  10  to drive existing loudspeakers  30  without the need to run speaker wires (not shown) from the home entertainment or stereo system to each loudspeaker  30 . The loudspeaker  30  supports at least one speaker  34  and an air port  33  and is connected to the receiver  14  via speaker wires (not shown). The receiver control panel  32  houses the various controls that allow the user to define the operation of the receiver  14 . A graphic equalizer  34  allows for the adjustment of the tonal characteristics of the sound, on several bands, by use of individual sliding knobs  35 . A balance knob  36  allows for the adjustment of the sound between the right and left channels. A fader knob  37  allows for the adjustment of the sound between front and rear channels. A volume knob  38  allows for the adjustment of the playing volume. A conditioning location selection switch, hereinafter conditioning selection switch  39  allows the user to select the location of the signal conditioning for that particular receiver  14 . A channel selection knob  40  allows for individual channel selection on a per speaker basis. A power switch  41  allows the receiver  14  to be powered on and off. A power cord  42  with a two-prong plug  43  allows the speaker assembly to be powered by a conventional wall socket (not shown) and the receiver  14  includes an optional battery power supply (not shown) that allows the receiver to operate in a completely wireless(not including speaker wires), re-chargeable manner. The function of the controls located on the receiver control panel  32  as they relate to the operation of the receiver  14  will be discussed in further detail herein below. 
     2. Operation of the Preferred Embodiment 
     In accordance with the preferred embodiment of the present invention and as shown in FIG. 5, the transmitter  13  used in conjunction with the speaker system  10  operates in the following manner. A home theater/stereo system  50  is used to feed sound signals  51 , consisting of a left channel  52  and right channel  53 , into the transmitter  13 . The sound signals  51  can be that generated by a variety of devices including a stereo receiver, CD player, cassette deck, video disc, DVD, etc. (Not shown). The sound signals  51  are first processed by a surround sound processor  54  in which the desired effect as defined by the user-selected surround sound effects buttons  26 . The surround sound processor  54  generates an in-phase sound signal  55  consisting of a front-left sound signal  56  and a front-right sound signal  57 , and an out-of-phase sound signal  58  consisting of a rear-left sound signal  59  and a rear-right sound signal  60 . The in-phase sound signal  55  and the out-of-phase sound signal  58  are fed to an in-phase transmitter  65  and an out-of-phase transmitter  66 , respectively. The in-phase transmitter  65  and out-of-phase transmitter  66  consist of FM transmitters used to transmit an in-phase broadcast signal  67  and an out-of-phase broadcast signal  68 . 
     The in-phase sound signal  55  and the out-of-phase sound signal  58  are also fed, in parallel, to signal level conditioning circuitry  70 , where the in-phase sound signal  55  and the out-of-phase sound signal  58  are further conditioned in terms of tonal characteristics of the sound, adjustment of the sound between the right and left channels, adjustment of the sound between front and rear channels and playing volume as defined by the user on the transmitter control panel  20  via the graphic equalizer  21 , balance knob  23 , fader knob  24  and volume knob  25 , respectively. The level conditioning circuitry  70  generates a conditioned in-phase sound signal  71  consisting of a conditioned front-left sound signal  72  and a conditioned front-right sound signal  73 , and a conditioned out-of-phase sound signal  74  consisting of a conditioned rear-left sound signal  75  and a conditioned rear-right sound signal  76 . The conditioned in-phase sound signal  71  and the conditioned out-of-phase sound signal  74  are fed to a conditioned in-phase transmitter  80  and a conditioned out-of phase transmitter  81 , respectively. The conditioned in-phase transmitter  80  and the conditioned out-of-phase transmitter  81  consist of FM transmitters used to transmit a conditioned in-phase broadcast signal  82  and a conditioned out-of-phase broadcast signal  83 . 
     In FIG. 6, the receiver  14  used in conjunction with the speaker system  10  operates in the following manner. The conditioned in-phase broadcast signal  82  and the conditioned out-of-phase broadcast signal  83  are received by a conditioned in-phase signal receiver  90  and a conditioned out-of-phase signal receiver  91 , respectively. The conditioned in-phase signal receiver  90  and conditioned out-of phase signal receiver  91  consist of FM receivers that retrieve the particular frequency generated by the conditioned in-phase transmitter  80  and the conditioned out-of-phase transmitter  81 , respectively. 
     Once received by the conditioned in-phase signal receiver  90  and the conditioned out-of-phase signal receiver  91 , the conditioned in-phase sound signal  71  and the conditioned out-of-phase sound signal  74  are sent to a conditioned signal decoder  92  wherein a single channel is selected, i.e. the conditioned front-left sound signal  72 , the conditioned front-right sound signal  73 , the conditioned rear-left sound signal  75 , the conditioned rear-right sound signal  76 , or a center signal (not shown), to be played by the particular receiver  14 . The center signal is a combination of both the conditioned front-left sound signal  72  and the conditioned front-right sound signal  73 , creating a monophonic signal. The selection is made by the user via the channel selection knob  40  located on the receiver control panel  32 . Thus, a first selected conditioned signal  93  is produced by the conditioned signal decoder  92 . 
     The in-phase broadcast signal  67  and an out-of-phase broadcast signal  68  are received by an in-phase signal receiver  100  and a out-of-phase signal receiver  101 , respectively. The in-phase signal receiver  100  and out-of-phase signal receiver  101  consist of FM receivers that retrieve the particular frequency generated by the in-phase transmitter  65  and an out-of-phase transmitter  66 , respectively. 
     Once received by the in-phase signal receiver  100  and the out-of-phase signal receiver  101 , the in-phase sound signal  55  and the out-of-phase sound signal  58  are sent to an unconditioned signal decoder  102  wherein a single channel is selected, i.e. the front-left sound signal  56 , the front-right sound signal  57 , the rear-left sound signal  59 , the rear-right sound signal  60 , or a center signal (not shown), to be played by the particular receiver  14 . The center signal is a combination of both the front-left sound signal  56  and the front-right sound signal  57 , creating a monophonic signal. The selection is made by the user via the channel selection knob  40  located on the receiver control panel  32 . Thus, a selected signal  103  is produced by the unconditioned signal decoder  102 . 
     The selected signal  103  is fed to signal level conditioning circuitry  105 , where it is further conditioned in terms of tonal characteristics of the sound, adjustment of the sound between the right and left channels, adjustment of the sound between front and rear channels and playing volume as defined by the user on the receiver control panel  32  via the graphic equalizer  34 , balance knob  36 , fader knob  37  and volume knob  38 , respectively. The level conditioning circuitry  105  generates a second selected conditioned signal  106 . 
     The first selected conditioned signal  93  and second selected conditioned signal  106  are connected to the conditioning selection switch  39 , allowing the user to select which signal is sent to an amplifier  110  that drives the loudspeaker  30 . In providing this selection capability, the user of the speaker system  10  can allow the transmitter  13  to condition the signal being listened to or can control it remotely in the location of the receiver  14 . 
     While the preferred embodiments of the invention have been shown, illustrated, and described, it will be apparent to those skilled in this field that various modifications may be made in these embodiments without departing from the spirit of the present invention. It is for this reason that the scope of the invention is set forth in and is to be limited only by the following claims.