Note: Descriptions are shown in the official language in which they were submitted.
WO91/06158 PCT/CA90/0033~
` 2~7~39~
RECORDED MESSAGE DELIVERY SYSTEM
TECHNICAL FIELD
This invention relates to a recorded message
audio delivery system for use by an individual
listener.
BRCK~ROUND ART
The presentation of tourist and/or other
e~hibitions has always been a problem. Visitors to
e~hibitions of any type require information concerning
the e~hibits. Such information may be provided by
guide books, by written notices attached to each
e~hibit, verbally by guides accompanying a conducted
tour, verbally by a pre-recorded announcement either
individually made from e~uip~ent carried by the
visitor or centrally in the location of the e~hibit.
Generally verbal presentation i~ preferred since the
visitor's visual attention may then remain wholly on
the e~hibits.
There have been various difficulties in making a
satisfactory verbal presentationO Among these are the
fact that it is difficult to provide for simultaneous
presentations in different languages and that it has
been necessary for visitors to follow a set route
conforming to the sequencing of the presentation.
This may be true whether or not a guide person gives
the presentation or whether it is tape recorded.
If individually portable tape recording apparatus
is carried by each visitor, the problem of language
may be theoretically solved by providing the visitor
with apparatus whi~h delivers messages in the language
of his choice. However, this entails the provision of
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W091/06158 PCT/CA90/0033'~
2~7~3~2 2 -
a large amount of apparatus by the management of the
respective exhibition to allow for appropriate choice
of apparatus specific to a particular language.
While some e~hibitions are highly profitable
tourist attractions, a very large number are cultural
museums ("museums" is used here in its widest sense to
mean any place of study including buildings, display
grounds, gardens, battlefields or parts thereof, in
which are preserved or exhibited objects of permanent
interest). Often such museums are run by charitable
organizations or on low budget government funding. In
neither case is a large amount of money usually
available for investment in large` quantities of
e~pensive apparatus ..
With the e~pansion of the tourist industry, some
e~hibitions have bee~ using individually portable
message announcing systems which are operated to
remotely from transmitters in each of several regions
through which a visitor passes. The transmitters may
transmit, for example, o~ the AM broadcast band of
frequency or on the infrared wave band. Such devices
have improved the form o presentation somewhat in :~.
that Yisitors may proceed through the e~hibition of
their own speed and, to an e~tent, may choose their
route. However, it is still not possible for them to
choose to hear specific information about a particular
e~hibit, nor is it possible to program different
language versions of a tour altarnately on the same
device. Thus, in at least some of these systems, the
user is not able to choose the desired message, and
: the number of messages per area is typically limited
to one which covers the entire area including multiple
e~hibits. Such message may be too long for the
convenience of the user or may lack detailc
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w09l/06tsx PCT/CA9OtO0338
3 207~392
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Although it has not been possible for a listener to
choose to hear any one message in the language of his
pre selected choice, at least one attempt has been
made directed towards solving this problem. Suc~
attempt is believed to have involved the use of radio
frequency bands normally reserved for use by the
hearing impaired. The use of such bands, as with the
use of any other radio wave bands used, necessarily
limit the number of diff~rent ~requencies utilizable
for transmission of different messages from a
transmitter without interference. Nevertheless, an
attempt was made to provide a choice of a very f ew,
(believed less than four) different transmission
frequencies which the listener might tune. It is
believed that any practical embodiment of this concept
is not now available.
DI SCLOS~3RE OF THE INVENTION
.
The inventor in the present case approached the : :
pro~lem from a different angle than that taken by .
prior operators in the field.
The inventor took the view that multi-channel
propagation techniques might be used to overcome some
of the previous difficulties. The use of such
techni~ues presented i~mediate apparent difficulty due
to the possibility of interference with commercial
interests such as a radio. The inventor concluded
that conflict with commercial radio having rights to
certain frequencies might be avoided by the use of low
: power sufficient for use in localized regions but not
so great as to cause problems with radio broadcastin~
authorities. Problers of interference with the
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WO91iO6158 PCT/CA90/0033X
2~7D392
message transmission by high powered transmission from
commercial radio may be dealt with by blocking the
commercial transmission.
As an example, the inventor concluded that use of
the FM band should not be dismissed as impracticable
since it offered advantages in providing a large
number of frequencies to which reception might be
tuned.
The inventor, moreover, appreciated that the
increased cost in production of a large number of
discrete messages and provision of receivers having
tuners for listener selecting a message by entering a
number might be offset by the provision of receivers
which might each be programmed to receive messages in
only one language chosen by the listener and
reprogrammable to another language as required. If
each receiver is capable of such versatility the
actual cost of eguipment may be reduced to a minimum.
Still further the inventor appreciated that the
cost of the equipment might be reduced still further
by storing the messages for transmission in a storage
medium which does not need moving into di~ferent
positions to play the messages. Thus messages may
retrieved with negliqible wear and tear and negligible
risk of malfunction. Thus the inventor envisaged
storin~ the messages in digitized form on a computer
chip.
Accordingly there is provided a system for
delivery of prerecorded messages in response to
selection by a listener, comprising; recorded messages
stored in computer memory, different messages in one
language being associated with a message
identification datum and translations of any one
message being associated wîth the message
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WO 91/06158 PCr/CA90/0033~
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identification datum for said any one message; and
each translation of any one message being associated
with the message identification datum for said any one
message; a transmitter settable to transmit each ~ :
message in one language on separate non-interfering
frequencies in a locality cell and to transmit
translations of eaoh message on separate
non-interfering frequencies; at least one receiver
programmable to receive transmitted messages in one
language, and reprogrammable to receive transmitted
trans].ated messages in another language, by allocation
of a set of reception frequencies for ~he receiver
corresponding to the transmission frequencies for the . .
messages or for translated messages in said other
language; and manuall~ operable selection means to
select a receiver setting whereby a reception
frequency is manually selectable by the listener in
accordance with message identification indicia.
The power of the transmitter, for practical
purposes be sufficiently low as to avoid interference
by transmissions produced using the system of the
invention with commercial radio.
When an operator enters the identification
indicia or control panel of a receiver, the system
maps that number to the transmitter frequency which
contains the desired messa~e in the desired message in
the desired language. Two users, desiring the same
messag~e but in different languages, would enter the
same message number but would receive the respective
30 messages on two different frequencies. .
The inventor has also envisa~ed that the system .
may transmit:on a power low enough to allow, when a
large number of messa~es are involved, frequency to be : -
reused within the confines of the environment. . .
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~Q~392 - 6 - .
Thus an e~ample of aspects of the invention, in
operation might in~olve an art gallery to which the
visitors included diferent nationalities. A German
speaking visitor, a French speaking visitor and an
English speaking visitor will be referred by way of
e~ample ~ut it will be appreciated that many other
languages may be involved and the number of such
languages is mainly dictated by demand and e~pense.
Moreover, while an art galler~ is e~emplified the
system is utilizable for many other environments some
of which will be discussed briefly below.
The FM band is presently attractive for use in
the invention for regulatory and economic reasons. It
includ~s many other bands than the FM commercial
15 hroadcast band ~88.1 - 107.9 MHz). In the near
future, it is envisaged that it may be attractive to
produce systems above 1 GHz - eliminating many system
issues (interference, fre~uency reuse, number of
channels, etc.).
If the FM band is to be used, conflict with other
channels may be avoided by being a~le to use locally
unassigned channels, i.e. the system will not be
overpowered by local channels but may operate on an
out of town channel because it will be weak relative
to the immediate vicinity of the transmitter. Lower
power operation may limit the reception range of the
particular messa~e aiming to keep it within the
confines for the museum.
The visitors to the art gallery may be each
provided with an FM radio receiver, hereinafter
referred to as a "wand". In most environments, such . .
as the e~emplified art galler~ tour the wand would be
battery powered so that there are no trailing wires.
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W091/06158 PCT/CA90/00338
7 _ 2~0392
The wands are adapted to receive transmissions from an
FM transmitter operating at sufficiently low power so
as not to interfere with any commercial broadcasting
station and, in some countries, at sufficiently low
power so as not to contravene any regulations
concerning interference with commercial broadcasting.
Discrete prerecorded messages in each language,
in this e~ample in French, German and English, may be
stored in digitized form on a computer chip. This
form of storage may have at least two distinct
advantages over tape, or other recordings. First, in
receiving messages from the chip there are no moving
parts and negligible wear and tear on the system.
More importantly, it is easy to a~cess the chip or
retrieval of any message at any t;me.
The transmitter retrieves messages from the chip
and transmits retrieved messa~es on carefully selected
pre-chos~n non-interfering frequencies as will be
further discussed~
Each e~hibit in the gallery or other museum or
environment may be provided with a separate message in
each of the languages to be used and each eæhibit may
be identified to the Yisitor by an identification mark : .
which is conveniently a number. This identi~ication
mark may zlso be used to identify messages relating to
that eshibit and translations of that message language
of the message.
Each wand is programmable to any o~ the available
languages.
Thus the three visitors will be provided with
wands programmed for French, German and English. The
programming of each wand is changeable and may be
carried out on site. Conveniently, a unit is provided .
to carry out the funckions of battery charging and
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programming, so that a ~isitor may be provided with a
charged wand custom prog~ammed to receive the language
of his choice. However, it will be appreciated that
programming and charging are functionally separate
tasks and their provision within one unit is for
convenience only.
Once provided with a charged programmed wand the
visitors may wander at will among the e~hibits,
listening to information only when th~y wish it and
relating to the specific e~hibit or a small group of
e~hib ts in which they are interested. Moreover, the
information will be provided in a language which they
may understand.
Thus, if all three visitors are in a close group
inspecting say, e~hibit #6, each one of them may
activate a selector marked for #6 on his wand. Each
wand will receive a similar message but in a different
language and a message on separate non-interfering
frequenci~s.
The choice oE the non-interfering frequencies is
deliberately chosen as the transmitting frequencies
for similar messages in different languages at the
same location. The transmitting frequencies for
different messages in the same language should also be
non-in~erfering . From eshibit ~6 it is not necessary
to visit e~hibit #7. The visitor may go forward
seguentially or non-sequentially or retrace his tracks
to an earlier e~hibit which interested him.
To further e~plain the operation of the system,
possible variations of the above example will now be
considered, partiall~ in disclosure of the invention
and partially to e~plain the principles involved in
the choice of the fre~uencies chosen at the
transmitter and programmed at the receiver.
WO 91/06158 PCI/CA90/00338
- 9 2~3~2
If all three visitors have wands programmed to,
say English, and ea~h visitor chooses to inspect
different exhibits, say #5, #6 and #7 in close
proximity to one another, then each visitor will
activate a selector marked for e~hibits #5, ~6 and #7
respectively. Each visitor will hear only the message
for the particular e~hibit which he is inspecting -
since the frequeneies chosen for transmission are
chosen so as not to inter~ere with each other.
If an additional visitor is inspecting, say
exhibit #5 but is listening in, say, French, he will
activate the same selector on his wand as does the
visitor who is listening on his wand in English.
However, due to programming of the wands the visitor
who is listening in French will select a different
frequency from that selected by the visitor who is
listening in ~nglish. The use of FM frequencies is
important due to the number of available
non-interfering fre~uencies. Of course, when using
the FM band it is important that the low power
transmissions of the system do not inter~ere with any
commercial fre~uencies in use. This may be easily -
accompli~hed by limiting the power.
The reverse problem, i.e. potential interference
of the system transmissions by commercial radio, is
more difficult. The inventor has envisaged solving
this problem by means of blocking reception on the
frequency when interference occurs. Thus a system
transmission may be accompanied by an identi~ication
signal for the transmission. I~ a non-identified
transmission is detected reception may be hlocked.
This will have the e~fect of also blocking the system
transmission but it is believed this is less
objectionable than garbled transmission. The problem
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W091/06158 PCT/CA90/00338
-- 10 --
~7~392
may substantially be avoided by suitable choice of
frequencies.
The use of FM frequencies is that reception may
be less impeded by obstructions between the
transmitter and receiver than is the case when using
AM frequencies or infrared beams. In any case
infrared beams are obstructed by sunlight if used out
of doors. Moreover, the use of FM frequencies may
make it convenient to operate the system on a cellular
basis somewhat similar to the basis on which cellular
telephones opexate. As visitors move from one cell to
another frequencies ma~ be reus~d for different
messages. Since visitors may actuate selectors which
do not correspond to e2hibit indicia, it is wise to
block reception on any frequencies associate~ with
these selectors. Thus, if ~he wan~ is programmed to
receive messa~es on ~requencies 40, 45, 509, 55 and 60
but only four recorded messages coxrespondi~g to
e~hibits l, 2, 3 and 4 are available on requencies
40, 45, 50 and 55, reception may be blocked on
frequency 60. Alternately, programming means may be
provided to program frequencies of zero or the like to
correspond to all selector positions to which a
message frequency is not assigned.
The selectors of each wa~d are preferably
:stationary ~pressure sensitiYe seilectors to minimize
wear due to moving p~rts. The wand is conveniently
designed to include a contact portion ha~ing access
means for battery charging and for programming. The
plug portion may be plugged into a socket of
ch~rging/programming bank for storage and or .
: distribution. ~The chargingfprogramming bank may be
:located at any convenient location, but is
conveniently near to a visitor entry zone. It may be
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wos1/06158 PCT/CA90/0033X
7~9~
designed as a self-serve distribution point for wands
from which visitors select a wand when they enter and
deposit it when they leave. Supervision will be
necessary to supervise the appropriate programming of
wands. However, if no wand is located in a socket
marked for a desired language, it should cause very
little delay to take a wand from another socket and
reprogram it as desired.
BRIEF DESCRIPTION OF THE DRAWIN~S
An embodiment o the invention will now be
l0 described with reference to the drawings, in which: -
Figure l is a block diagram illustrating
the transmitter sub systems;
Figure 2 is a block diagram illustrating
the receiver sub systems; and
Figure 3 is a diagrammatic sketch ~f a
cellular layout. ~
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MODES FOR CARRYING OUT THE INVENTION
A transmitter used in a system embodying the
present in which may be of any suitable design and is
within the competence of anyone skilled in the art.
The transmitter may be an rf, infra-r~d, spread
spectrum or time division multiple2ed, transmitter
i.e. the transmitter may utilize any propagation media
capable cf supporting multiple channels example based
of standard rf FM transmission is broadcast band
should be recognized that system is not limited to the
method but can be applied to any multi-channel
propagation technique capable of supporting
multi-channel (voice or data) operation such as
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~ 091/061~8 PCT/CA90/0033X
2~70392 - 12 -
infrared, spread spectrum, tdma. Thus a conventional
FM transmitter, may be used such as one as depicted in
the block diagram of Figure l. Such a transmitter may
comprise an audio input lO, control circuits 14, a
synthesizer 15, for RF frequencies, a modulator 18, an
amplifier 20, and a power supply 26 and an output
antenna 24. Additionally, conventional filters, such
as input filters at the audio input lO, and an output
filter anterior matching means 22 may be provided.
Since more than one carrier frequency is required, a
transmitter channel selector is also provided. Each
such transmitter arranged to transmit or its selected
frequencies is arranged to transmit over a pre-chosen
region in accordance with the power supply. In the
previously us~d e~ample of the art gallery, if
e~hibits #4, #5, #6~ and #7 are grouped together a
single transmitter may be suitably locatad to transmit
messages on four non-int~rfering ~requencies in
English, to transmit translations in French or another
four non-interfering frequencies, and to transmit four
translations in German or yet another four
frequencies, or yet another four~ Such a region may
be regarded as a "cell" are with hereinaf~er be
referred to as such. It is to be emphasized that the
choice of languages of each translation and the number
of frequencies used per cell is merely a matter of
convenience.
An additional feature of the transmitter which is
of some importance as an optional feature of the
inventor is means 16 to provide for an end of message
signal. An oscillator is provided to generate an end
of message signal which is transmitted with the audio
signal. The end of message signal need not be in the
audio range. Its purpose is to provide a signal to
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- 13 - ~ 2~703~2
the recei~er to switch off after deliverin~ the
message a pre-determined number of times.
A further modification includes the provision of
means for the generator of a continuous tone for
inclusion of system identification message either tone
or data message transmitted at a level or at
modulation rate inaudible to the user to serve as a
system identifier. This may allow a receiver to
confirm that receive signal is being transmitted by
the system and that the message should be presented to
the user. It may also indicate an end of message
cycle before recycling.
Because the transmitters operate at such low
power, for e~ample 50 milliwatts, further transmitters
will be necessary if any significant region is to be
covercd. In theory it is possible~ when moving into
the adjacent region covered by a second transmittar,
to reuse the frequencies of the first transmit~er for
different message~ in the sec~nd region. In practice
if this is attempted, either reception near the
margins of the region may be unacceptably poor or
~here will be interference of transmissions between
the cells. If two different messa~es are transmitted
on the same frequency from two adjacent cells and then
coverage from each cell overlaps the other then
distortion will result at the transition boundary and
the user may receive the other message if they walk
into the adjacent cell. Thus, transmitters in
adjoining cells should preferably operate or different
frequencies. Moreover, if quality transmissions is to
be maintained within cells it may not always be
possible to re-use frequencies, even when a cell in
which it is desired to test frequencies is spaced from
the cell in which the frequencies are previously used
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WV91/06158 PCT/CA90/0033
2 ~ ~3 9 2 - 14 -
by a distance corresponding to another cell. However,
frequencies may usually be re-used when alternately
spaced and one suitable cell patte~n for such use is
shown in Figure 3. Figure 3 shows a pattern for
twelve (12) cells #l to #12.
Assuming that each consecutively numbered cell
~requencies are to be reused, no consecutively
numbered cells must adjoin one another. Thus cell ~2
must be spaced from each of cells #l and #3 by at
least one other cell~ When this spacing is observed
for all the twelve (12~ eonsecutively numbered cells,
a group of cells as surrounded by the solid black line
in Figure 3 may be formed. This group of cells may be
- repeated as often as desired in the same patter.
The spacing of one cell between cells in which
frequencies are re-used is to a practical minimum
requirement or reusing fre~uencies. It is, however,
preferred only to re-use frequencies in each group of
cells. Thus cell #l would always utiliæe the same
fre~uencies and each cell #l is well separated from
any other cell #l~ A similar situation e~ists for
sach other celI in the group.
A message storage unit may comprise digital voice
storage in solid state memory. Thus moving mechanical
parts and fragile storage media such as audio tape may
be avoided. The message storage unit may include the
system identification message either a tone or data
message transmitted at a level or modulation rate
inaudible to ~he user to serve as a system
identifier. This allows receiver to confirm that
receive signal is being transmitted by the system.
Receivers for receiving transmisxions from the
transmitters are also largely conventional and
comprise a power supply 30 which is preferably a
wosl/06158 PCT/CA90/0033X
2~7~3~2
- 15 -
rechargeable battery, control means 36 for the battery
with a switch 34, receiver control circuits 38, a
synthesizer 48 for the receiver frequency which is
frequency is changed through user intervention from
keyboard 40. Signal from the synthesizer 48 and from
the input from an antenna 44 and front end matching
and input filter means 45 is input to 16. The heart
46 of the receiver comprises conventional mixer and
intermediate ~requency amplification stages.
Downstream of the mi~er and the i.f. amplifier is a
detector 47 for loss of re~uency and for detecting
the end of message signal.
A display 42 may,be pro~ided on the receiver to
indicate onfoff condition and which keyboard selection
has been made.
An important feature of the receiver which is not
conventional is frequency selection means 50 which
activates appropriate control circuits 38 in response
to keying by the user of keyboard 4~ to cause the
local oscillator of synthesizer 48 to operate at the
appropriate frequency. The frequency selection means
50 is programmable and repr3grammable such that, for
one programming, certain keyings select corresponding
frequencies and, for other programmings, the same
keyings select other corresponding frequencies. Thus,
when programmed for one languages, user input of the
key~oard as indicated b~ indicia or the e~hibits will
only result in messages'in the one language. ~he ''
selection means 50 may be reprogrammed to a different
langua~e where desired. Conveniently access to the
selection means 50 for reprogramming is through any
sultable plug and socket access or other access.
The control means 40 and selection means 50
accept programming infor~ation, tsanslate a m~ssage
WO 91/061~X P~/CA90/0033~
2~70392
number to a programmed operating frequency, control
sub-systems (synthesi~er, charge indicator, etc.) for
proper operation and reception of message, and monitor
charger/programming inputs share common connection to
detect if receiver is in a charsing or programminy
unit. If the controller detects that the receiver is
being changed the controller erases programmed data
requiring the receiver to be reprogrammed. This
ensures receiver is properly programmed for user
language and prevents unauthorized reissue of r~ceiver
to a user without proper accounting u~e. The
controller may also verify program data and verify
transmitted system identification.
The selection means 50 may be any easily
reprogrammable firm ware, or e~ample an ~EPROM. A
program for the operation of the selection means 50 is
simple in concept. Thus, for example, if the keyboard
is a ten digit keyboard and selections of fre~uency
are possible for user keyings of 00 to 99, then:
if language A is selected then for example, for
20 any cell,
keying 01 selects frequency 26;
keying 02 selects frequency 36;
keying 03 selects frequency 46;
For cell 2,
keying Q4 selects frequency S6
keying 05 selects frequency 66
keying 06 selects frequency 76
For cell 3,
keying 07 selects frequency 86
keying 08 selects frequency 96
keying 09 selects frequency 16
if language B is selec~ed keying
suitably be: ~
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- 17 ~ 2~ ~ ~39 2
keying 01 selects frequency 13
keying 0~ selects frequency 27
keying 03 selects frequency 03 etc.
Since cells 1 and 2 are separated from each other
by at least one other cell the repetition of cell #2
frequencies in cell #l may not cause interference
problems. Evidently, numerous variations and
safeguards are possible.
A programmer may physically have one slot or
socket per language into which a wand may be inserted
for pro~ramming. The programmer may store channel set
for each language; accepts changes to sets from an
e~ternal computer or by installation of a memory
integrated circuit which contains channel data; detect
}5 that a wand has been placed into slot or socket, and
program the wand and verify programming by reading a
check sum sent by the receiver which is calculated
from the programmed data. At this point it is
discovered that the wand is not properly programmed
the programmer may provide an audible response to the
operator to indicate pro.gramming status - succ8ssful
or unsuccessful, track usage of the wand, inde~ an :~
internal counter per programm ng attempt, and inde~ an ~ -
internal counter by language.
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