`(12) Patent Application Publication (10) Pub. No.: US 2009/0046869 A1
`
`
` Griffin, JR. et al. (43) Pub. Date: Feb. 19, 2009
`
`US 20090046869A1
`
`(54) WIRELESS AUDIO RECEIVERS
`
`Publication Classification
`
`(76)
`
`Inventors:
`
`Paul P. Griffin, JR., Nashville, TN
`(US); Joshua A. Sharpe-Stirewalt,
`
`(51)
`
`Int. Cl.
`(2006.01)
`H04R 1/10
`(52) US. Cl. .......................................................... 381/74
`
`Correspondence Address:
`HORNKOHL INTELLECTUAL PROPERTY
`
`LAW: P-L-L-C
`RC. BOX 210584
`NASHVILLE, TN 37221 (US)
`
`(21) Appl. NO':
`
`11/839546
`
`An audio system uses two frequencies to transmit a left and
`right audio signal to a pair of wireless earphones. Mono
`receivers in each of the earphones respectively receive the
`right or left audio signals and produce an audio output. The
`system includes a base that docks to the earphones such that
`they can be charged and configured to receive an audio output
`at the selected transmission frequency. The audio signal can
`be produced by the base or received from a portable electronic
`device to which the base is coupled. The base can also func-
`tion as an FM transmitter for the device and utilize the
`
`(22)
`
`Filed:
`
`Aug. 16, 2007
`
`device’s controls and display.
`
`52
`
`32
`
`34
`
`54
`
`
`
`LeftEarbud
`
`
`antenna
`
`
`
`TDA7040
`
`«2067099
`
`40
`
`(3007099
`
`TDA‘7040
`
`
`
`‘htEarb‘ud
`T
`42
`antenna
`
`
`“ ail
`
`
`
`BaseStation
`
`
`
`Dock interface
`. 44
`
`charging
`circuit
`
`30
` processor
`
`
`46
`
`30610
`50111128
`
`LCD
`screen
`
`Bose Exhibit 1053
`
`Bose v. Koss
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 1 0f 6
`
`US 2009/0046869 A1
`
`6" :
`
`17
`
`17
`
`8/5
`
`FIG.
`
`1
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 2 0f 6
`
`US 2009/0046869 A1
`
`52
`
`32
`
`34
`
`54
`
`
`
`LeftEarbud
`
`Y
`
`anienna
`
`RichtEarh’ud
`
`Y
`
`anienna
`
`42
`
`(3007099
`
`0
` 30
`
`, 44
`
`
`
`BaseStation
`
`audio
`source
`
`‘
`
`LCD
`screen ‘
`
`46
`
`FIG. 2
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 3 0f 6
`
`US 2009/0046869 A1
`
`“130
`
`1
`
`06
`
`122
`
`40
`
`8C}
`
`114
`
`Power
`Y
`
`Supp!
`
`Receiver
`
`I
`
`
`
`
`
`
`
`103
`
`1 32
`
`108
`
`124
`
`Power
`
`Suppiy I
`
`
`Receiver
`
`
` 103
`
`97
`
`88
`
`11
`
`6
`
`113
`
`118
`
`Verification
`
`System
`Memory
`
`III
`
`Display
`
`
`Microwntraller
`
`I PowerSuppiy
`I Deviael/O P011
`
`
`
`
`
`Accessory I/O Port
`
`98
`
`92
`
`82
`
`90
`
`Macrocomroller
`
`as I_II
`
`H
`
`120
`
`Verification
`System
`
`Power
`Suppiy
`
`Pass Through
`Connector
`
`Earphone
`Dock
`
`Earphone
`
`Dock I
`
`External Power
`,
`Suppiy Connectuon
`
`103
`
`a
`1"6
`
`123
`
`HG. 3
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 4 0f 6
`
`US 2009/0046869 A1
`
`156
`
`'1 54
`
`FIG. 47(0)
`
`
`
`FiG. Mb)
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 5 0f 6
`
`US 2009/0046869 A1
`
`
`
`
`
`Patent Application Publication
`
`Feb. 19, 2009 Sheet 6 0f 6
`
`US 2009/0046869 A1
`
`170
`
`HG. 5(a)
`
`
`
`'FIG. 5(b)
`
`
`
`US 2009/0046869 A1
`
`Feb. 19, 2009
`
`WIRELESS AUDIO RECEIVERS
`
`CROSS-REFERENCES TO RELATED
`APPLICATIONS
`
`[0001] Not Applicable
`
`STATEMENT REGARDING FEDERALLY
`SPONSORED RESEARCH OR DEVELOPMENT
`
`[0002] Not Applicable
`
`REFERENCE TO SEQUENCE LISTING OR
`COMPUTER PROGRAM LISTING APPENDIX
`
`[0003] Not Applicable
`
`BACKGROUND OF THE INVENTION
`
`[0004] Wireless headphones are known that allow a user to
`receive transmitted audio signals from a transmitter on an
`audio player. These headphones typically include a single
`receiver that receives the audio signal and produces an output
`signal that is provided to each of the headphones through an
`electrical connection. While these devices provide the ben-
`efits of wireless headphones, the headphones are larger and
`more comfortable than the popular, compact, wire connected
`ear buds. This is due to the fact that the circuitry used to
`implement the receiver in the headphones is bulky and has
`large power requirements. In addition, the formats, such as
`Bluetooth or Wi-Fi, typically used for wireless headphones
`require expensive, often proprietary, receiver circuitry. Prior
`art wireless headphones also lack the bandwidth to transmit
`true stereo audio from the head phones due to cost; and power
`limitations. Therefore, what is needed is an improved, inex-
`pensive device for providing an audio player with wireless
`headphones with high quality stereo audio reception.
`
`BRIEF SUMMARY OF THE INVENTION
`
`[0005] An embodiment of the present invention is directed
`toward a device for producing a stereo audio output. The
`device includes a first audio output having a receiver and a
`speaker and a second audio output having a receiver and a
`speaker. The audio outputs can be headphones, earphones or
`ear buds. The receivers are preferably mono receivers. A base
`station wirelessly transmits a left audio signal to the receiver
`in the first audio output in a first broadcast frequency range
`and a right audio signal to the receiver in the second audio
`output in a second broadcast frequency range. The first and
`second broadcast frequency ranges are preferably FM, broad-
`cast frequency bands that are user selectable. Alternatively,
`the device can be configured to search for two broadcast
`frequency ranges having an acceptable amount of noise and
`set the first and second broadcast frequency ranges to the
`identified acceptable broadcast frequency ranges. The base
`station further includes at least one dock for coupling to at
`least one of the first and second audio outputs such that a
`power supply in the at least one of the first and second audio
`outputs can be charged by a power supply of the base station.
`The base station is designed to be coupled to a media player
`such that an audio signal from the media player can be broad-
`cast to the first and second audio output. The base station
`includes a first transmitter for transmitting the left audio
`signal and a second transmitter for transmitting the right
`audio signal.
`
`[0006] Another embodiment of the present invention is
`directed toward a wireless audio system that includes a first
`earphone or headphone having a mono receiver and a speaker
`and a second earphone or headphone having a receiver and a
`speaker. A base transmits a right audio signal to the first
`earphone or headphone and a left audio signal to the second
`earphone or headphone. The base is adapted to be removably
`coupled to a portable electronic device such that an audio
`signal is received from the portable electronic device by the
`transmitter. The base includes a charger for charging the
`earphones or headphones and the power for the charger is
`received from the portable electronic device. The housing of
`the base is configured to physically couple to a housing ofthe
`portable electronic device. The user inputs of the portable
`electronic device can be used to control functions of the
`system.
`[0007] Yet another embodiment of the present invention is
`directed toward a method of wirelessly transmitting an audio
`signal from a base to a pair of receivers. The audio signal is
`received with the base from a portable electronic device
`coupled to the base. In accordance with the method, the audio
`signal is converted into a right audio transmission signal in a
`first frequency range and a left audio signal in a second
`frequency range. The right audio transmission signal is trans-
`mitted from the base to a first of the pair of receivers and the
`left audio transmission signal is transmitted from the base to
`a second of the pair of receivers. The base is configured to
`transmit the right and left audio signals at a first and second
`FM frequency selected by a user. A power supply of the
`receivers is charged with the base. The receivers are prefer-
`ably mono receivers.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWINGS
`
`FIG. 1 an illustration of an accessory constructed in
`[0008]
`accordance with an embodiment of the present invention
`coupled to a portable electronic device;
`[0009]
`FIG. 2 is a functional block diagram of a wireless
`transmitter and a pair of receivers constructed in accordance
`with an embodiment of the present invention;
`[0010]
`FIG. 3 is a functional block diagram of a wireless
`transmitter and a pair of receivers constructed in accordance
`with another embodiment of the present invention;
`[0011]
`FIGS. 4(a-d) are illustrations of a preferred pair of
`ear buds for use with an embodiment ofthe present invention;
`and
`
`FIGS. 5(a) and 5(b) are illustrations of a preferred
`[0012]
`method of docking an ear bud to a base station in accordance
`with an embodiment of the present invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`[0013] The present invention is directed toward an audio
`device, or an accessory for use with an audio device, which
`includes a pair ofwireless headphones, earphones or ear buds
`that, receive audio transmissions transmitted from the audio
`device. Referring now to FIG. 1, all illustration of an acces-
`sory 2 constructed in accordance with an embodiment of the
`present invention coupled to a portable electronic device 4 is
`shown. The accessory 2 has a transmitter that is designed to
`couple with the portable electronic device 4 such that audio
`signals received by the accessory 2 from the portable elec-
`tronic device 4 can be broadcast to a pair of wireless ear-
`phones 6 and 8 that are placed in the ears of a user. While any
`
`
`
`US 2009/0046869 A1
`
`Feb. 19, 2009
`
`transmission frequency can be used, each earphone 6 and 8 is
`preferably configured to receive a transmission from the
`accessory 2 transmitted at a different FM broadcast fre-
`quency. The FM transmit frequencies can be pre-selected as a
`commonly unused frequency band, such as 88.7 and 88.9, or
`selected manually by a user of the accessory 2. To manually
`set the reception frequencies, the user simply identifies two
`FM frequencies that are not currently being used by a local
`radio station. The user then enters the two selected frequen-
`cies using the inputs 16 and display 18 ofthe accessory 2. The
`accessory 2 can also be configured to automatically search the
`FM frequency bands to locate two unused frequencies for
`reception by the earphones 6 and 8. The accessory 2 scans
`every available FM frequency, records a signal level and
`selects the two lowest signal levels for use in broadcasting to
`the earphones 6 and 8. The earphones 6 and 8 can then be
`automatically configured to receive the selected frequencies
`by connecting the earphones to the docks 15 on the accessory
`and sending a control signal to receivers in the earphones that
`instruct them to tune to the selected transmission frequencies.
`Alternatively, the earphones 6 and 8 may be manually con-
`figured to receive the appropriate frequency by a user entering
`the frequency on an input of the earphones 6 and 8.
`[0014] The receivers in the earphones 6 and 8 are preferably
`mono receivers as discussed in, more detail herein. Mono
`receivers are smaller and less expensive, and require less
`power than stereo receivers. This makes mono receivers much
`better suited for use in wireless earphones, buds or head-
`phones that have limited power supplies. Also, the use of
`mono receivers allows each earphone to be constructed with
`an identical circuit, thereby, further reducing the production
`costs associated % with the earphones.
`[0015] The accessory 2 receives a right and left audio signal
`from the device 4 and transmits the right audio signal to one
`earphone 6 on a first transmission frequency and the left audio
`signal to the other earphone 8 on a second transmission fre-
`quency. The accessory 2 has an input/output connector such
`as a USB, 30 pin, audio jack, etc. that is used to electrically
`and physically couple the accessory 2 to a corresponding
`input/output connector on the device 4. The particular type of
`input/output connector selected for the accessory 2 depends
`upon the type of input/output connector 011 the device 4 for
`which the accessory 2 is designed. The accessory 2 also
`preferably has a housing 10 that is designed to be coupled
`with the portable electronic device 4 such that the accessory 2
`and the portable electronic device 4 function, and can be
`carried, as a single unit.
`[0016]
`In the embodiment of FIG. 1, user inputs 16 such as
`scan, up/down, etc. and a display 18 are provided on the
`accessory 2 housing itself. The user inputs 16 on the acces-
`sory 2 allow a user to select a broadcast frequency for broad-
`casting the audio signals received from the device 4 to each of
`the earphones 6 and 8. Unused frequencies are preferably
`selected by the user for transmission to the earphones to
`minimize any distortion in the signal. The accessory 2 can
`also be configured to instruct the device 4 to search for a clear
`transmission frequency if the device 4 is so equipped. The
`user inputs 16 are preferably a small number of soft buttons
`that can, be reconfigured to control the various functions,
`such as up, down, volume, mute, etc., of the accessory 2 such
`that the number of user inputs required by the accessory, and
`their associated costs, are minimized.
`[0017] The accessory also includes a set of earphone jacks
`or docks 15 that are adapted to receive the earphones 6 and 8.
`
`In the embodiment of FIG. 1, the docks 15 are jacks that are
`inserted into the audio channels of the earphones 6 and 8,
`which contain a mating jack covered by an ear adapter, to
`couple to the earphones 6 and 8 to the accessory 2. The
`earphone docks 15 provide charging power to the batteries in
`the earphones 6 and 8 such that the earphone batteries can be
`charged while they are coupled to the docks 15. The batteries
`are preferably small rechargeable lithium ion batteries but
`may be any type. A power switch 17 is provided on the
`earphones 6 and 8 such that they can be turned, off when not
`in use to conserve battery power. Alternatively, the earphones
`6 and 8 may be equipped with a sensor such as a capacitive,
`pressure or temperature sensor that automatically turns the
`earphones 6 and 8 on when they are placed in the ear and off
`when they are removed from the ear. In addition, control
`signals, such as the selected reception frequencies for the
`earphones 6 and 8, can be communicated from the accessory
`2 to the earphones 6 and 8 through connections in the docks
`15 when the ear phones are coupled to the docks 15.
`[0018] The accessory 2 can preferably write text to the
`portable electronic device’s display 12 and repurpose the
`controls 14 of the portable electronic device 4 to control
`functions of the accessory 2. In such an embodiment, the
`accessory 2 can tune to frequencies selected with the controls
`14 of the device 4. The accessory controls 16 or device con-
`trols 14 can be used to manipulate accessory generated menus
`displayed on a display screen 12 of the portable device 4. By
`selecting the proper menus, device 4 and accessory 2 func-
`tions, such as the volume, operating mode, display, etc., can
`be controlled through manipulation of the controls 14 or 16.
`Which particular controls to use to control which particular
`functions will be determinedbased upon the particular type of
`portable electronic device 4 for which the accessory 2 is
`designed or configured.
`[0019] The accessory 2 user inputs 16 may also include a
`voice activation system that allows a user to control the acces-
`sory 2 or device 4 through voice commands. In such an
`embodiment, the user inputs 16 include a microphone that
`detects the voice commands. Voice recognition software then
`interprets the output of the microphone into accessory 2 or
`device 4 commands.
`
`[0020] Referring now to FIG. 2, a functional block diagram
`of a cost effective embodiment of the present invention hav-
`ing relatively few components is shown. The embodiment
`consists of a base station 30 that can be coupled to a right 32
`and left 34 ear bud through a docking interface 44. The base
`station 30 can also be coupled to an external audio source
`through a device interface 70. The base station 30 wirelessly
`transmits audio signals received from the audio source to the
`ear buds 32 and 34. While the embodiment of FIG. 2 is
`
`described as being coupled to the audio source, the base
`station 30 can contain an internal audio source 31 that gener-
`ates the audio signals transferred to the ear buds 30 and 34 if
`desired. The base station 30 has user inputs 46 that can be
`used to select a transmission frequency for each of two trans-
`mitters 66 and 68. A processor 36 in the base station controls
`an LCD display screen 38 such that the selected transmission
`frequencies are displayed on the screen 38. The processor 36
`communicates the selected transmission frequencies to
`receivers 40 and 42 in the ear buds 32 and 34 when the ear
`
`buds are coupled to the base station through the docking
`interface 44. The docking interface 44 also allows a charging
`circuit, 60 to recharge batteries 62 and 64 in the ear buds 32
`and 34 when they are coupled to the docking station 44.
`
`
`
`US 2009/0046869 A1
`
`Feb. 19, 2009
`
`[0021] When the ear buds 32 and 34 are disconnected from
`the base station 30 and placed into the ears of a user, the
`processor 36 wirelessly transfers audio signals received
`through the device interface 70 to the receivers 40 and 42,
`CDC7099s in the embodiment shown in the ear buds 32 and
`34 through a pair of transmitters 66 and 68. The receivers 40
`and 42 provide their output to decoders 48 and 50 which in
`turn provide an output to speakers 52 and 54 in each ofthe ear
`buds 32 and 34. The left ear bud decoder 48 provides a left
`stereo output to its speaker 52 and the right ear bud decoder 50
`provides a right stereo output to its speaker 54.
`[0022] By utilizing separate transmission frequencies to
`transmit the left and right audio signals to each ofthe ear buds,
`the circuitry required to implement the receivers in the ear
`bids is minimized. In additions the power requirements, and
`thus the size of the required size of the power supplies, of the
`receivers are minimized such that the ear buds can be imple-
`mented as separate pieces that fit in the ears of a user. The use
`of separate transmission frequencies also provides increased
`bandwidth for the transmission and a corresponding increase
`in audio quality.
`[0023] The desired cost and complexity of the accessory
`will determine the level of functionality installed in any par-
`ticular embodiment. Referring now to FIG. 3, a functional
`block diagram of an accessory constructed in accordance
`with a more featured and complex embodiment of the present
`invention coupled to a portable electronic device is shown.
`The device 80 is coupled to the accessory 82 through a pair of
`mating interfaces 84 and 86. In the embodiment shown, the
`interfaces 84 and 86 between the device 80 and accessory 82
`include a digital data channel, an analog audio signal line and
`a power connection. The accessory 82 exchanges digital data
`with the portable electronic device 80 through the digital data
`channel. The various functions of the accessory 82 are con-
`trolled by a microcontroller 90 can communicate with the
`microcontroller 92 of the device 80 through the interfaces 84
`and 86 when the device 80 and accessory 82 are coupled
`together. By establishing digital communications between
`the controllers 90 and 92, the accessory 82 can exchange
`digital control information with the device 80. Thus, the
`accessory 82 can respond to manipulation of the user inputs
`96 of the portable device 80 and display information on the
`display 88 ofthe device 80 as discussed in more detail herein.
`The accessory 82 can also read data from and write data to the
`memory 97 of the device 80. The digital data exchanged
`between the accessory 82 and device 80 may also include a
`digital media file and meta data concerning the digital media
`file.
`
`[0024] The accessory 82 includes a pair of transmitters 98
`and 100 that transmit audio signals through antennas 103 to
`two receivers 102 and 104 in the earphones 106 and 108. The
`accessory 82 receives an analog or digital audio signal from
`the device 80 through the interfaces 84 and 86. The accessory
`82 then creates right and left audio radio broadcast frequency
`signals corresponding to the audio signal received from the
`device 80. The left and right audio signals are each transmit-
`ted through one ofthe transmitters 98 and 100 to the receivers
`102 and 104 at two selected frequencies. The transmit fre-
`quencies can be pre-selected and set at the factory, manually
`set by a user or automatically determined by the accessory 82.
`For example, the microcontroller 90 can be used to alter the
`transmit frequencies of the transmitters 98 and 100 in
`response to a user manipulating a user input 96 or 110 of the
`device or accessory. If the transmits frequencies are altered
`
`from a preset value, the earphones 106 and 108 can be recon-
`figured to receive at the selected frequencies when the dock
`connectors 122 and 124 of the earphones 106 and 108 are
`connected to the earphone docks 126 and 128 ofthe accessory
`82. This is preferably accomplished through a menu driven
`interface that uses the display 111 and inputs 110 of the
`accessory.
`
`[0025] The accessory 82, device 80 and earphones 106 and
`1 08 can be powered in a number of different manners depend-
`ing upon the parameters of the device to which the accessory
`is adapted to be coupled. The accessory 82 may be a parasitic
`device that takes its power from a power supply 116 of the
`portable electronic device 80 if the device power supply is
`capable of supplying the power required by the circuitry of
`the accessory 82. However, in alternate embodiments, the
`accessory 82 may contain an internal power source 118 for
`powering the accessory 82 and charging the portable elec-
`tronic device 80. An external power supply connection 120
`also can be coupled to the portable electronic device 80
`through the accessory 82 if desired. This allows the device 80
`to be charged while it is coupled to the accessory 82 and the
`accessory is functioning such that the accessory can be used
`while the device is being charged. In addition, the external
`power connection 120 provides the increased power required
`by the accessory without draining the power supply 1 1 6 ofthe
`device. The earphone docks 126 and 128 are used to supply
`power from the accessory 82 to the power supplies 130 and
`132 of the earphones 106 and 1080 when they are docked to
`the accessory 82.
`[0026] The accessory 82 can also preferably be selectively
`configured to transmit on a single FM channel such that a
`standard radio receiver call receive audio from the device 80
`
`if desired. An accessory 82 constructed in accordance with a
`preferred embodiment of the present invention also sends
`data to the portable electronic device 80 that instructs the
`portable electronic device to display the currently selected
`transmitter frequency or channel on the display screen 88 of
`the device 80. By utilizing the display 88 ofthe device 80, the
`cost of the components required to implement the accessory
`82 is minimized. In addition, the accessory 82 can preferably
`display menus on the screen on the device and allow a user to
`manipulate the menus through the use ofthe controls 96 ofthe
`portable electronic device 80 to control the functions of the
`accessory 82. Conversion codes and routines for converting
`device outputs into accessory inputs, or vice versa, can be
`stored in the accessory memory 99.
`[0027] A transmitting accessory 82 constructed in accor-
`dance with an embodiment of the present invention may also
`include an accessory verification system 113 that works with
`a device verification system 114 to verify that the accessory
`82 is being used by an approved portable electronic device 80
`or that the accessory 82 is an approved accessory for the
`device 80. The verification system 113 and 114 can use an
`identification resistor, a digital certificate, validation code or
`any other type of identification system or circuitry known in
`the art to verify that the device 80 and accessory 82 are
`produced by approved entities. Digital rights management
`software may also be included in the accessory 82 for use by
`the microcontroller 90 to verify the authenticity of any copy-
`righted material being transmitted from the device 80 by the
`accessory 82.
`[0028] An accessory 82 constructed in accordance with all
`embodiment ofthe present invention also preferably includes
`a pass through connector 112 that allows a second accessory
`
`
`
`US 2009/0046869 A1
`
`Feb. 19, 2009
`
`to couple to an output or input port ofthe electronic device 80
`through the accessory 82. For example, the accessory may
`have a USB port that allows an external device to be coupled
`through the accessory to the USB port of the device if the
`accessory covers the USB port of the device when it is
`coupled to the device. Alternatively, the pass through connec-
`tor 112 can be used to supply power to the device 80 through
`the accessory 82.
`[0029] Referring now to FIGS. 4(a) and 4(b), a preferred
`pair of ear buds 150 and 152 for use with an embodiment of
`the present invention is shown. Each ear bud 150 and 152
`includes an audio output end 154 having a soft tip for provid-
`ing audio to the ear of a user and a power switch 156 for
`turning the ear bud 011 and off. In addition, each ear bud has a
`removable clip 158 that can be removed and replaced with an
`ear piece 160. FIGS. 4(c) and 4(d), which is adapted to secure
`the ear buds 150 and 152 to the exterior ofan ear ofa user. The
`removable clips 158 and 160 allow a user to pick their pre-
`ferred method of securing the ear buds to their ears.
`[0030] Referring now to FIGS. 5(a) and 5(b), a preferred
`method of docking an ear bud to the base station in accor-
`dance with an embodiment of the present
`invention as
`described herein is shown. The dock consists of a male jack
`170 that is inserted into the audio channel 172 of the ear bud
`
`assembly 174. Once the jack 170 is inserted into the channel
`172, an electrical connection is established between the jack
`170 and the circuitry of the ear bud assembly 174. This
`electrical connection is used to charge and configure the ear
`bud assembly 174 as described above.
`[0031] Although there have been described particular
`embodiments of the present invention of new and useful
`WIRELESS AUDIO RECEIVERS, it is not intended that
`such references be construed as limitations upon the scope of
`this invention except as set forth in the following claims.
`What is claimed is:
`
`1. A device for producing a stereo audio output, said device
`comprising:
`a first audio output having a receiver and a speaker;
`a second audio output having a receiver and a speaker;
`a base station for wirelessly transmitting a left audio signal
`to said receiver in said first audio output in a fast broad-
`cast frequency range and a right audio signal to said
`receiver in said second audio output in a second broad-
`cast frequency range.
`2. The device of claim 1 wherein said first and, second
`broadcast frequency ranges are FM broadcast frequency
`bands.
`3. The device of claim 1 wherein said base station further
`
`comprises at least one dock for coupling to at least one of said
`first and second audio outputs such that a power supply in said
`at least one of said first and second audio outputs can be
`charged by a power supply of said base station.
`4. The device of claim 1 wherein said first and second audio
`outputs are headphones or earphones.
`5. The device of claim 1 wherein said base station is
`
`designed to be coupled to a media player such that an audio
`signal from said media player can be broadcast to said first
`and second audio output.
`
`6. The device of claim 1 wherein said base station further
`comprises a first transmitter for transmitting said left audio
`signal and a second transmitter for transmitting said right
`audio signal.
`7. The device of claim 1 wherein said receivers are mono
`radio receivers.
`8. The device of claim 1 wherein said device searches for
`two broadcast frequency ranges having an acceptable amount
`of noise and sets said first and second broadcast frequency
`ranges to said identified acceptable broadcast frequency
`ranges.
`9. A wireless audio system comprising:
`a first earphone or headphone having a mono receiver and
`a speaker;
`a second: earphone or headphone having a receiver and a
`speaker; and
`a base for transmitting a right audio signal to said first
`earphone or headphone and a left audio signal to said
`second earphone or headphone.
`10. The system of claim 9 wherein said base is adapted to
`be removably coupled to a portable electronic device such
`that an audio signal is received from said portable electronic
`device by said transmitter.
`11. The system of claim 10 wherein said base includes a
`charger for charging said earphones or headphones and said
`power rom said charger is received from said portable elec-
`tronic device.
`
`
`
`12. "he system of claim 9 wherein said base includes a
`charger for charging said earphones or headphones.
`13. The system of 10 wherein said base further comprises
`a housi 1g configured to physically couple to a housing of said
`portable electronic device.
`14. The system of claim 10 wherein user inputs of said
`portable electronic device can be used, to control functions of
`said system.
`15. A met hod of wirelessly transmitting an audio signal
`from a base to a pair of receivers; said method comprising the
`steps of:
`converting said audio signal into a right audio transmission
`signal in a first frequency range and a left audio signal in
`a second frequency range;
`transmitting said right audio transmission signal from said
`base to a first of said pair of receivers; and
`transmitting said left audio transmission signal from said
`base to a second of said pair of receivers.
`16. The method of claim 15 further comprising of config-
`uring said base to transmit said right and left audio signals at
`a first and second FM frequency selected by a user.
`17. The method of claim 15 further comprising further
`comprising the step ofcharging a power supply of saidreceiv-
`ers with said base.
`
`18. The method of claim 15 further comprising the step of
`receiving said audio signal with said base from a portable
`electronic device coupled to said base.
`19. The method of claim 15 wherein said receivers further
`
`comprise headphones or earphones.
`20. The method of claim 15 wherein said receivers are
`mono receivers.
`
`