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Patent 1227865 Summary

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Claims and Abstract availability

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(12) Patent: (11) CA 1227865
(21) Application Number: 464236
(54) English Title: MUSIC DELIVERY SYSTEM
(54) French Title: SYSTEME DISTRIBUTEUR DE MUSIQUE ENREGISTREE
Status: Expired
Bibliographic Data
(52) Canadian Patent Classification (CPC):
  • 350/27
  • 363/6
(51) International Patent Classification (IPC):
  • H04H 60/93 (2009.01)
  • H04H 20/76 (2009.01)
  • H04J 1/00 (2006.01)
(72) Inventors :
  • JONES, MARKLEY L. (United States of America)
  • EDWARDS, LEE (United States of America)
  • BORDELON, JOHN H. (United States of America)
(73) Owners :
  • MUSIC LOVERS'JUKEBOX, INC. (Afghanistan)
(71) Applicants :
(74) Agent: GOWLING WLG (CANADA) LLP
(74) Associate agent:
(45) Issued: 1987-10-06
(22) Filed Date: 1984-09-28
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
538,573 United States of America 1983-10-03

Abstracts

English Abstract




MUSIC DELIVERY SYSTEM
ABSTRACT OF THE DISCLOSURE
A music delivery system permitting a
subscriber to select from among a plurality of
available music selections, particular selections
that the subscriber wishes to hear at any time.
The plurality of music selections are "played" at
a central "jukebox" facility. They are frequency
multiplexed onto one or more communication
channels that are typically used to carry video
information, such as a cable television channel.
The video channel information is distributed to
individual subscribers either via unused channels
of a cable television system, by direct broadcast
at commercial television frequencies, by direct
satellite transmission to a subscriber, or by some
other means. A subscriber uses a converter box to
demultiplex and thereby select a desired musical
selection for demodulation. Demodulation can take
place in the subscriber's television or in some
other apparatus. Music selections are selected in
a similar fashion to the manner in which particu-
lar channels of a cable television system are
selected for video viewing. Each music selection
is on an audio sub-channel of a video channel. The
music on the sub-channels is continuously played
in such a way that any specific selection can be
chosen at any time.


Claims

Note: Claims are shown in the official language in which they were submitted.




The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:

1. A method for making substantially simultaneous-
ly available to a subscriber a plurality of audio entertainment
selections and permitting the subscriber to choose a particu-
lar selection for listening comprising the steps of:
storing said plurality of audio entertainment
selections on laser-readable recording/playback medium;
reading said medium and substantially
simultaneously generating a plurality of electrical signals
one corresponding to each of said plurality of audio enter-
tainment selections;
frequency multiplexing the plurality of
electrical signals to form a composite signal including
information of each of said plurality of audio selections;
transmitting the frequency multiplexed
composite signal to said subscriber;
demultiplexing, from the composite signal, the
electrical signal corresponding to said particular audio
entertainment selection; and
transducing the demultiplexed signal into
said particular audio entertainment selection.

2. A method according to claim 1 wherein said
step of transmitting comprises the step of transmitting the
composite signal over a cable.

3. A method according to claim 2 wherein said
transmitting step comprises the step of transmitting over
a coaxial cable.

4. A method according to claim 1 wherein said
step of demultiplexing comprises the steps of selectively

21



frequency converting a portion of said composite signal
corresponding to said particular audio entertainment
selection to a predetermined intermediate frequency; and
wherein said step of transducing comprises
the step of demodulating the converted portion at said
intermediate frequency to provide said particular audio
entertainment selection.

5. A method according to claim 4 wherein said
step of demodulating comprises the step of demodulating
using audio circuits of a television receiver.

6. An arrangement for making substantially
simultaneously available to a subscriber a plurality of
audio entertainment selections and permitting the subscriber
to select a particular selection for listening, comprising:
means for storing said plurality of audio
entertainment selections on a laser-readable recording/
playback-medium;
means for reading said medium and substantially
simultaneously generating a plurality of electrical signals
one corresponding to each of said plurality of audio
entertainment selections;
means for frequency multiplexing the plurality
of electrical signals to form a composite signal including
information of each said plurality of audio selections;
means for transmitting the frequency multi-
plexed composite signal to said subscriber;
means for demultiplexing, from the composite
signal, the electrical signal corresponding to said particular
audio entertainment selection; and
means for transducing the demultiplexed signal
into said one audio selection.
22



7. An arrangement according to claim 6 wherein
said transmitting means comprises means for transmitting the
composite signal over a cable.

8. An arrangement according to claim 7 wherein
said transmitting means comprises means for transmitting over
a coaxial cable.

9. An arrangement according to claim 8 wherein
said demultiplexing means comprises means for selectively
frequency converting a portion of said composite signal
corresponding to said particular desired audio entertainment
selection to a predetermined intermediate frequency; and
wherein said transducing means comprises a
television receiver audio circuit for demodulating said
particular audio entertainment selection.

10. A method according to claim 4 wherein the
demodulating step comprises the step of demodulating with an
FM broadcast receiver.

11. An arrangement according to claim 9 wherein
said demodulating means comprises an FM broadcast receiver.
23

Description

Note: Descriptions are shown in the official language in which they were submitted.


7~365

MUSIC DELIVERY SYSTEM

BACKGROUND OF THE INVENTION

This invention relates in general to
music delivery systems. More specifically, the
invention relates to "jukebox" type systems
whereby a user can select and hear a particular
musical selection whenever desired. In essence,
the present invention provides a system for
bringing jukebox music directly to a subscriber.
The subscriber can select a particular one or
series of pieces of audio entertainment to be
"played" in the subscriber's home at any time.
The traditional jukebox is a unit
including a plurality of records. A user can
select, by the manipulation of switches, a
particular record to be played. That record is
played and all those within earshot of the jukebox
- speakers listen to the record which has been
selected. An improved version of the traditional
I jukebox can be found in many restaurants. A
separate selector box and speaker are placed at
each table in the restaurant. The jukebox is
wired to each selector box so that a record can be
selected by a patron at any table. Of course,
only one record at a time is played and the music
is delivered directly to the speaker at the table.
A music lover is able to bring into the
home particular audio entertainment that he or she
wishes to hear by buying records and playing them
on a home high-fidelity stereo system.
Unfortunately this requires buying each record to
be played. This can get quite expensive. An
alternative is for the music lover to listen to

;~27~36~

the radio. The problem with this is that one can
only listen to the particular music selected by
the disc jockey. There is no way to hear
particular songs when the listener wishes to hear
them without buying a record or a cassette tape.

SUMMARY OF THE INVENTION

The present invention provides a music
lover with an alternative to buying and collecting
records while providing the ability to select for
listening any one of a plurality of selections at
any time. A subscriber simply manipulates a
keyboard to select a particular song or sequence
of songs desired. within about 30 seconds or
less, the subscriber's first choice begins to
play.
In its preferred embodiment, the music
delivery system delivers music via a cable TV
system already serving the subscriber. For the
cable TV subscriber, it provides an active music
retrieval system that allows choices from a
monthly updated list of a plurality (such as 200)
of music selections. These may, for example,
range from top 40 hits to golden oldies to jazz to
country-western to classical to gospel.
when subscribers wish to hear a musical
selection, they simply refer to a monthly cable
guide which lists all available songs. Each
selection is numbered. The subscriber simply keys
in that number on a converter box and within
approximately 30 seconds, the selection begins to
play.

3 ~:27~3~S

In one embodiment, the system utilizes
the sound system built into a television set. If
the subscriber is satisfied with such a sound
system, the selected music can simply be "played"
through the television. In an alternative
embodiment, music selected can be played over an
existing stereo system or an optional
amplifier/speaker arrangement provided as a
peripheral device.
The subscriber receives music from a
central library through the same cable that
provides cable television service to the
subscriber's home, business or other location. A
significant advantage of the music delivery system
according to the present invention is that it
utilizes an existing cable TV system without the
need to rewire countless homes.
Typically, a television cable system
brings a cable to the subscriber's home. This
cable carries 30 or more video information
channels, each channel being about 6 MHz in
bandwidth. The subscriber is provided with a
converter box which selectively converts a desired
channel to a particular unused video broadcast
channel in the area such as, for example, channel
3. The subscriber tunes the television to channel
3 and leaves it there. As different cable video
channels are desired or viewing, they are
converted to channel 3. Conversion usually takes
place in a converter box having a plurality of
switches for selecting a desired cable channel.
Most cable television systems have a number of
channels which are unused or which can be made
vacant for use by the music delivery system.

3L2~78~S;

The music delivery system according to
the present invention frequency multiplexes
approximately 75 to 200 audio channels into a 6
MHz bandwidth video channel so that 75 to 200
different audio "sub-channels" can be Somali-
tonsil transmitted via a single video
channel. In one embodiment, a particular audio
selection is played continuously (over and over
again) on a given audio sub-channel. To hear a
desired selection, the particular sub-channel on
which that selection plays is demultiplexed by
converting it to a predetermined frequency such
as, for example, the sound intermediate frequency
(IF.) of a television. A particular video
channel of a cable system carrying the audio sub-
channels can be selected on the subscriber's
already existing video converter box. An
additional converter box can be used to tune to
the particular audio sub-channel carrying the
music selection desired.
From the subscriber's point of view, the
system works like an active retrieval library of
approximately 200 selections. The selections can
be routinely updated such as, for example, on a
monthly basis or more often whenever a new "hit"
occurs. The musical selections are played at a
central jukebox facility using either a plurality
of conventional turntables or any other type of
reproduction system that can produce electrical
signals from prerecorded records. In the
preferred embodiment, a laser disc player or
players are used to play back from optically
readable discs.

5 Lowe

The heart of the laser system is a
semiconductor laser that shines a beam of coherent
light onto a rapidly spinning optically readable
disc on which a music selection has been
encoded. The laser beam "reads" the coded disc
and converts it into an electrical signal.
In one embodiment, the audio signal for
each different audio selection is generated by a
separate audio playback unit, such as a laser disc
lo audio playback unit. The audio signals are then
multiplexed into a single video channel or a small
number of video channels. With a laser disc
- system, a plurality of read-out beams can be used
for each record that is being continuously played.
Thus, the same musical selection can be placed on
a plurality of different audio sub-channels of a
video channel, each sub-channel having a different
"phase" with respect to the others. Thus, if a 3
minute song is played repeatedly on six different
audio sub-channels with equally spaced starting
times, one would never be more than a half a
minute from the beginning of the musical selection
desired.
The audio signals for 200 (more or less)
such audio channels could be generated, as in the
example above, by 200 compact audio disc playback
units, each playing a different song with its own
laser beam. However, in a preferred embodiment,
the system will use a more practical technique
which uses only one playback unit. As many as 200
audio channels could be recorded, with specially
designed recording equipment, on a single video-
type laser disc because it has the full bandwidth
of a video channel. This disc could then be
played back at the cable heat with a playback unit

6 ~2'78~i

similar to conventional video disc playback units.
All of the audio channels recorded on the disc
could then be played back by a single laser beam
and can be transmuted through a single video cable
channel simultaneously. All of the audio channels
would thus be available at the subscriber's
location at the same time.
The preferred embodiment will be a laser
video disc system; but instead of just one laser
"reading" each disc, a plurality of such lasers
will be employed, so that if the average song
lasts three minutes and six lasers are used, the
beginning of any given song will never be more
than approximately 30 seconds away. From one disc
containing 200 musical selections, six lasers
could be used to generate signals for 1200 audio
channels. Each of the 200 musical selections
would be carried on six of these 1200 channels but
with starts at 30-second intervals. By trays-
milting the 1200 audio channels, which are equivalent to six video channels, through six
channels of the cable, the system would have the
capability of delivering any of the 200 selections
-- from the beginning of the selection, within
approximately 30 seconds -- to the system in the
subscriber's home. Start and stop signals can be
incorporated into the system so that the user's
musical choice automatically switches to the audio
sub-channel carrying the next beginning of the
selection desired.
The subscriber's audio converter box
could include a microprocessor based system having
a memory so that one could program a sequence of
desired musical selections, including repeat plays
of a single song or a variety of songs in a


. ..

7 ~22~ s

predetermined order. The converter box would
respond to the microprocessor based system by
tuning to each particular appropriate audio sub-
channel in the order programmed by the user.
One video cable channel having a
bandwidth of 6 MHz can contain a number of
different audio sub-channels, the number being a
function of the signal format used for the audio
information. If each sub-channel is of the
standard TV FM sound signal format, 75 different
sub-channels can be formed in each video channel.
It is possible to increase the number of audio
sub-channels if a different signal format is
used. any different signal format requires that
the selected sub-channel signal be demodulated
with the resulting audio being impressed onto an
FM carrier with the standard TV FM sound signal
format so that it can be demodulated in the user's
television if the television is to be used as the
playback instrument.
In addition to the TV FM sound signal
format, there are several signal formats that can
be used, each of which has its own advantages and
disadvantages. With some there is a slight
depredation in audio quality either through a
decrease in the maximum audio frequency that can
be transmitted or in poorer signal to noise
performance or both. With appropriate selection
of signal format, it is possible to obtain about
200 audio sub-channels for each video channel.
For 200 audio sub-channels, the total signal width
(audio information) plus some guard band to
protect against mutual interference must be no
more than 30 kHz.

8 zz~s

One alternative format is that of an I
signal with limited high frequency audio response.
Using a modulation index of 1.67 (the same as that
for the standard TV FM signal) and constraining
the signal width to 30 kHz, a maximum audio
frequency of 5600 Ho can be used. This
corresponds roughly to AM broadcast quality and
may be considered too low a fidelity.
A second possible audio sub-channel
format is simple amplitude modulation. With a
bandwidth of 30 kHz, a maximum audio frequency of
15 kHz is theoretically possible, but because of
the absence of capture effect enjoyed by FM
systems, which reduces adjacent channel
interference, a maximum audio frequency of less
than 15 oh but not less than 12 kHz, is more
realistic. This quality is not far from that of
TV FM sound. Besides somewhat reduced high
frequency audio response, some increase in noise
and signal distortion can be expected.
Of these two formats, the second, the AM
system, is presently conceived as being
preferable.
The subscriber is provided with an audio
sub-channel converter which can be provided either
as part of the home subscriber's video converter
box supplied by the cable television operator or
as a separate unit. A separate unit is presently
conceived as being the most desirable arrangement.
Advantage may be taken of the fact that, in most
cable systems, the channel selected by the
subscriber's video converter box is converted to
channel 3. The subscriber's television set
remains tuned to channel 3 at all times. The
additional converter box for the jukebox system

9 365

could be designed for installation between the
television and an existing video cable converter
box supplied by the subscriber's cable television
operator. The desired video channel (carrying
many audio sub-channels) is selected on the
existing video converter box, with the desired
musical selections then being selected by the
additional audio sub-channel converter. Only one
design would thus be necessary for the audio sub-
channel converter, a decided economic advantage.
The "jukebox" concept claimed herein isn't limited to cable television systems. Rather,
it is applicable to any system by which a
traditional "video" channel of approximately 6 MHz
bandwidth can be delivered to a subscriber. For
example, some subscribers now receive television
pictures by direct transmission from a satellite
which transmits hundreds of video channels. One
or more of such channels could be dedicated for
"jukebox" service. An earth satellite receiver
from which a subscriber obtains video entertain-
mint could be fitted with an audio sub-channel
converter box so that jukebox selections can be
transmitted to the subscriber via the same
satellite-to-earth link.
Some television subscribers now receive
pay television transmissions from a traditional
broadcast station. These transmissions are
scrambled and the subscriber is given a decoding
box to unscramble the transmission before it is
coupled to the subscriber's television. In a
similar fashion, a video channel filled with audio
sub-channel music selections could be scrambled
and broadcast over the air in the same manner that
commercial television is broadcast. Subscribers

1 o 1~2786~;

could be given appropriate decoding apparatus and
converter boxes so that they could select the
desired music selections transmitted "over the
air".
Applicants' invention includes both a
method of delivering entertainment and various
apparatuses for providing subscriber jukebox
service. In effect, applicants' inventive method
comprises the steps of: generating electrical
signals corresponding to a plurality of different
pieces of audio information; frequency multi-
flexing the signals to form a composite signal
corresponding to said plurality of pieces of audio
information; transmitting the composite signal to
a subscriber; demultiplexing a particular one of
said plurality of pieces of audio information; and
transducing the particular desired piece of audio
information into an audio signal.
The generating step could include playing
records in the traditional manner, using one or
more laser beams to read an optically readable
audio disc containing a musical selection, playing
cassette tapes, or some other technique. The
frequency multiplexing could include the
multiplexing onto traditional cable television
frequencies, earth satellite transmission
frequencies, commercial television broadcast
frequencies, or other such arrangements. The
transmitting step could include the transmission
of frequency multiplexed signals over cables, over
the airwaves, etc. The demultiplexing would be
provided by an audio sub-channel converter box so
that the subscriber could select particular sub-
channels to be demultiplexed and demodulated. The
transducing could be through the television's

11 Lo 365i

audio system, the subscriber's stereo, or other
devices suitable for this purpose.
For the traditional television audio EM
format, there is provided a converter box for
selecting a particular audio sub-channel
including: means for receiving a video channel
input from a cable; means for generating a
synthesized local oscillator having a user
controllable frequency; means for mixing the cable
input with the synthesized local oscillator to
produce an intermediate frequency signal
containing the desired music selection; an output
channel video carrier oscillator; and means for
impressing the selected audio signal onto the
I output channel video carrier for coupling to the
subscriber's television.
For the AM signal format, there is
provided a converter box including: means for
synthesizing a local oscillator frequency for
converting a desired audio sub-channel to a first
intermediate frequency; means for converting the
selected audio at the first intermediate frequency
to a second intermediate frequency; means for
demodulating the audio at said second intermediate
frequency; means for modulating the demodulated
audio into an FM sound signal in television
format; and means for impressing the FM modulated
signal onto an output channel video carrier for
coupling to a subscriber's television.

DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a schematic diagram
illustrating the general concept of the present
invention;

12 7~365

FIGURE 2 is a block diagram of an audio
sub-channel converter for use with a television
audio signal format; and
FIGURE 3 is a block diagram of an audio
sub-channel converter for use with an AM format.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

General Concept
A plurality of musical selections are
"played" at a central "jukebox" facility 110.
Electrical signals are generated for each such
selection. Facility 110 can include either a
video bandwidth laser disc player or a plurality
of record players, laser disc players, cassette
tapes, or the like. The signals for individual
music selections are transmitted to a distributor
112. Distributor 112 can be either a cable
television operator, a satellite operator, a
commercial broadcast operator, or the like.
If distributor 112 is a cable operator,
the music selections are multiplexed onto one or
more cable television channels and distributed via
cable 114 to individual subscriber televisions
116. If distributor 112 is a satellite operator
or commercial television broadcaster, the video
channel information can be broadcast over the air
as represented by arrow 118 to either a master
antenna system symbolized by antenna 120, for
distribution to televisions 122 or broadcast
directly to individual TV subscribers as
symbolized by arrow 124 and televisions 126.

8~5
13

Constraints of Television Receiver
The sound channels of modern television
receivers accept a frequency modulated (FM) signal
having a peak carrier deviation of + 25 kHz.
Audio frequency response it 50 Ho to 15 kHz with a
high frequency reemphasis time constant network of
s being used to equalize noise performance
between high and low audio frequencies. FM signal
amplification and detection are done at an IF
frequency of 4.5 MHz, corresponding to the
frequency difference between the frequency
modulated aural carrier and the AM (vestigial side
band) modulated video (picture) carrier. The TV
set depends upon the presence of the visual
carrier to heterodyne the aural carrier down to
4.5 MHz through the action of the mixer stage in
the TV set. Therefore the TV set must be provided
not only with an appropriate FM sound carrier on
some TV channel, but with an appropriate visual
carrier as well, and they must be separated by 4.5
MHz. The visual carrier need not, of course, be
modulated with any picture information. It does,
however, perform an additional, and in this case,
desirable function of darkening the screen of the
TV set, which would otherwise be illuminated by
noise or snow.

Cable Channel Capabilities
The presently contemplated preferred
manner for transmitting music selections to
individual subscribers is via a cable television
system. Other transmission schemes include the
use of an "over the air" broadcast channel, direct
reception of a satellite communication channel,
etc. This portion of the description discusses

14 I

the constraints of a cable television system used
as the transmission medium to a subscriber.
Each individual television channel used
in CAT system is 6 MHz in bandwidth. Almost all
of this is filled with information. The signal
format and frequency assignments are the same or
similar to the channels used for broadcasting but,
on cable, additional channels are used. These lie
in frequency bands other than those allocated for
broadcasting, and, indeed, in bands occupied by
other broadcasting or communication services.
Because of the closed nature of the cable system,
mutual interference is not ordinarily encountered
if the cable system is installed and maintained to
high technical standards.
One or more of these channels could be
used for "jukebox" service. These would probably
be channels that are vacant on a particular cable
system already in place. The chosen channel
should be filled with as many frequency modulated
signals as is possible without mutual inter-
furriness, all spaced on contiguous sub-channels.
For simplicity, each signal should have
the same characteristics as that normally received
on a singular basis by the subscriber's TV set.
Thus, the modulating frequency range, peak carrier
deviation and reemphasis time constants should be
the same as for the FM audio signal in any To
broadcast. Given the peak deviation value of 25
kHz and maximum modulating frequency of 15 kHz, a
minimum spacing of 80 kHz is desirable. This is
based upon a common criterion that the spectrum
occupied by an FM signal is approximately twice
the sum of the peak carrier deviation and the
highest modulating frequency. This criterion is

~7~36~;

reflected in the choice of channel spacing for
standard FM broadcasting. The calculated value of
channel width is 180 kHz, and a spacing of 200 kHz
is used. If 80 kHz spacing is used for the
proposed service, then 75 possible music select
lions can be transmitted, assuming no two are
alike.

The Subscriber's Converter Box for an FM System
Different signal formats require
different subscriber converter box arrangements.
The first such format and converter box arrange-
mint described is for an FM system.
This discussion assumes the use of a
single 6 MHz cable channel containing 75 FM
signals (75 different music selections). The
signals transmitted on the cable are highly
accurate in frequency, i.e., having an error of
only + l kHz.
Referring now to FIGURE 2 there is shown
a block diagram for the subscriber's converter
box, referred to generally by reference numeral
200. An incoming signal from the subscriber's
cable television cable first passes through a band
pass filter 202 to reduce out-of-channel signals
and feed through of the converter's local oscil-
later to the cable system. The signal is mixed in
a mixer 204 with a local oscillator signal from a
synthesized local oscillator 206 and heterodyned
down to 4.5 MHz. A band pass filter 208 at 4.5
MHz allows only the desired signal to pass. The
bandwidth of filter 208 should be about 80-100
kHz. Oscillator 206 tunes in 80 kHz steps, and
must be accurate to within 1 or 2 kHz.
Therefore, it is preferably an indirect

16
J~2~86~;
synthesizer. Tuning of oscillator 206 is under
control of a selection and control unit 210
responsive to user command.
The 4.5 MHz signal from filter 208 is
used in two ways. It is detected, that is
converted to audio, to provide start and stop
tones needed by selection and control unit 210.
The signal from filter 208 is amplified by an
amplifier 212 which is coupled to a limiter 214.
Limiter 214 is coupled to an FM detector 216 which
provides the start and stop tones to selection and
control unit 210. The 4.5 MHz signal is also
- coupled to a AM modulator which produces as an
output an unmodulated video carrier and an FM
modulated carrier 4.5 MHz higher in frequency.
The AM modulation function is performed by a mixer
218. This is the total signal needed for output
to the TV set. An output channel video carrier
oscillator 220 driving the AM modulator must be
near (+ 250 kHz) to the proper video carrier
frequency for the channel to which the TV set is
tuned.
It is desirable to suppress any audio
output from the TV set when selection and control
unit 210 so dictates. This will occur between
music selections. There are two ways in which
this can be done. In no case must the I
modulated carrier be removed, its audio modulation
must be suppressed. This may be accomplished by
substituting a steady 4.5 MHz carrier, derived
from a crystal oscillator 222 for the 4.5 MHz FM
signal derived as described above or by detection
of the FM signal, suppression of the detected
audio between selections and demodulation onto a
4.5 MHz carrier. The last method is more direct,

36~
but the first is superior from the standpoint of
preventing sound distortion that could result in a
detection and demodulation process A mute
control signal is provided by selection and
5 control unit ~10 to a switch 224. Switch 224
selects, responsive to the presence or absence of
the mute control signal, the input to mixer 218 as
either the 4.5 MHz oscillation from oscillator 222
or the 4.5 MHz signal carrying music selected from
filter 208.
At the output of mixer 218 there is I
provided an output channel band pass filter 226
- which provides a filtered output signal from
converter 200 to the subscriber's television.
If desirer the audio signal that has
been demodulated can be coupled to the
subscriber's stereo or other amplifier/speaker
arrangement instead of being put into TV sound
format to be "played" through the television.

The Subscriber's Converter Box for an AM System
Referring now to FIGURE 3 there is shown
a block diagram of a subscriber converter box
suitable for use with an AM signal format
(presently preferred). The AM converter box is
referred to generally by reference numeral 300.
Using an AM format, a total signal
bandwidth of 30 kHz can provide a theoretical
maximum audio frequency of 15 kHz. In practice
the maximum audio frequency is somewhat
degraded. Because of the absence of the capture
effect enjoyed by FM systems, which reduces
adjacent channel interference, a maximum audio
frequency of less than 15 kHz, but probably no

18 eye

less than 12 kHz is more realistic. This provides
a sound quality not far from that of TV FM sound.
The converter box 300 block diagram of
FIGURE 3 assumes an input from a video cable
selector van television channel 3 (60-66 MHz).
Converter 300 is basically a low sense-
tivity AM receiver. Two frequency conversions are
used to attain adequate image rejection and
adjacent channel rejection. IF frequencies are
chosen to be standard frequencies for which
components are readily available The muting
function described in the FIGURE 2 embodiment is
still used, but the muting tones are now at
subduable frequencies. The 4.5 MHz VCO (voltage
controlled oscillator) may require stabilization
within a small phase lock loop to meet the + 1 kHz
tolerance discussed in the FM format section of
this description.
The channel 3 input signal is coupled
through a channel 3 band pass filter 302 and mixed
in a mixer 304 with a signal from a synthesized
local oscillator 306. The frequency of the output
of oscillator 306 is controlled by a selection and
control unit 308 which is responsive to user
command.
As in the case of FM converter box 200,
selection and control unit 308 is responsive to
start and stop tones and provides a mute control
signal. Mixer 304 provides a first conversion by
mixing the desired music selection to 10.7 MHz (a
standard IF frequency) where it is filtered by a
band pass jilter 310. A second conversion is
provided by mixing the output of filter 310 in a
mixer 312 with a signal from an oscillator 314
operating at 11.155 MHz. This provides an output

19 I S

at mixer 312 at ~55 kHz which is another standard
IF frequency. The 455 k~z output of mixer 312 is
filtered by a filter 316 and coupled to an AM
detector and muting unit 318. Selected audio from
AM detector 318 is coupled to a 4.5 MHz voltage
controlled oscillator 320 which provides an FM
sound signal in television format. This
television format FM sound signal is mixed in a
mixer 322 with a signal from an output channel
video carrier oscillator 324 which provides a
carrier for a television channel to be tuned by
the subscriber. The output of mixer 322 is
filtered by an output channel band pass filter 326
for coupling to the subscriber's television.
If desired, the audio signal that has
been demodulated can be coupled to the
subscriber's stereo, or optional amplifier/speaker
arrangement, instead of being put into TV sound
format to be "played" through the television.

Alternatives
It is possible to use more than one cable
video channel, if they are available, to increase
the number of music selections from which to
- choose. An extra channel might be used to
broadcast picture information giving current
information on the selections available. The
attending sound would be chosen from one of the
sub channels available on an adjacent 6 MHz channel
and heterodyned onto the correct frequency for the
sound carrier accompanying the picture.
There can be provided some means of
alerting the listener's converter box that a
particular selection has ended or is about to
begin. This is desirable to ensure that when a

~L227~6~;
selection is made it will be played from the
beginning, and when ended will not be played again
if another selection has been made. One means of
achieving this action is the use of two different
subduable tones, as discussed above. One, a
"start" tone, would be present just before a
selection, while the other, a "stop" tone, would
occur in a short burst immediately after the
termination of a selection. This would signal the
converter box to retune to the next selection
desired, or to search for whichever selection of a
number of chosen selections first occurs. Since
the normal range of frequencies used for tote-
vision sound is 50 Ho to 15 kHz, as previously
stated, the signal tones must be below 50 Ho.
Another option, of course, is to use tones well
above 15 kHz, an equally effective solution.
The concepts of the present invention can
be applied to other delivery systems such as, for
example, direct broadcast from a ground-based
transmitter, satellite transmission direct to a
subscriber, etc. or some combination of trays-
mission schemes.
While the invention has been described in
connection with what is presently considered to
be the most practical and preferred embodiments,
it is to be understood that the invention is not
to be limited to the disclosed embodiments but on
the contrary, is intended to cover various
modifications and equivalent arrangements included
within the spirit and scope of the appended claims
which scope is to be accorded the broadest
interpretation so as to encompass all such
modifications and equivalent structures.

Representative Drawing

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Administrative Status

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Administrative Status

Title Date
Forecasted Issue Date 1987-10-06
(22) Filed 1984-09-28
(45) Issued 1987-10-06
Expired 2004-10-06

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Application Fee $0.00 1984-09-28
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
MUSIC LOVERS'JUKEBOX, INC.
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Drawings 1993-07-27 3 66
Claims 1993-07-27 3 101
Abstract 1993-07-27 1 32
Cover Page 1993-07-27 1 15
Description 1993-07-27 20 734