United States Patent [191
[11]
Patent Number:
I 5,003,576
Helferich
[45]
Date of Patent:
Mar. 26, 1991
[54]
ANALOG/DIGITAL VOICE STORAGE
4,181,893
CELLULAR TELEPHONE
[75] Inventor:
'
Richard J. Helferich, 154 Donegal
Ave., Newbury Park, Calif.
FOREIGN PATENT DOCUMENTS
Assignees: Richard J. Helferich, Newbury Park;
0294961 12/1986 Japan ................................. .. 379/201
Martin A. Schwartz, Tarzana, both of.
0046044 2/ 1988 Japan ................................... .. 379/88
Cahf' ; a part "must
OTHER PUBLICATIONS
[21] Appl' NO‘: 338’290
[22] Filed:
Apr, 149 1989
Z. H. Meiksin and Philip C. Thackray, Electronic De
sign with Off-The-Shelf Integrated Circuits, Parker
Publishing Company, Inc., 1980, pp. 170-172.
The Engineering Staff of Analog Devices, Inc.,
Related US Application Data
[63]
Cordill .
(Llst continued on next page‘)
91320-3420
[73]
V1980 Ehmke -
4,233,500 11/1980
Continuation-impart of Ser. No. 110,002, Oct. 19, 1987,
igzégg-l-gaglgllocggnl‘iiséclg ?glgbook’ Jun‘ 1972’ pp.
abandoned, and Ser. No. 110,201, Oct. 19, 1987, Pat.
Ad
No. 77,496, Jul. 24, 1987, Pat. No. 4,905,003,
mun1cat1ons, Radio Communications Report, vol. 6, No.
No. 4,864,301, each is a continuation-in-part of Ser.
’.
1,
.
,,
.
‘.b
vFrn§emem fol: Shmwa’ dlsm “ted byVICM com“
8, Apr. 15, 1987, p. 28; Mobile and Pager, pp. 37-38.
[51]
Int. Cl.5 .................... .. H04M 1/65; H04M 11/00
[52]
US. Cl. ...................................... .. 379/88; 379/56-
379/63’
[58]
Field of Search ..................... .. 379/58, 59, 63, 62,
379/88
[56]
References Cited
Us. PATENT DOCUMENTS
$2512‘: '
'
Attorney, Agent, or Firm-Knobbe, Martens, Olson &
Bear
[57]
ABSTRACT
An analog-to-digital voice storage cellular telephone
phone comprises call answering circuitry which is acti~
3’437’76O 4/1969 Kawgashh‘na et aL _
’
.
for recording voice messages while the user is away
from the cellular telephone unit. In a preferred embodi=
ment, the analog-to-digital voice storage cellular tele=
3’073'896 V1963 Jame? -
1
_
Prim’? Dimmer-Thomas W- Brown
vated after a predetermined number of rings. Detection
3,466,392
9/1969
Calfee et al. .
circuitry
waits
to detect a SAT
signal
durin s a
_
_
_
,
3,470,472
3,651,413
3,654,560
3,659,043
3,662,380
9/1969
3/1972
4/1972
4/ 1972
5/1972
Suzuki et a1_ _
Wycoff .
Cath et a]. .
ZUCI'PHS 6! a1- cal'glle '
penod of time. Once the SAT s1gnal is detected a prere
corded outgoing message is transmitted to the caller.
The voice storage cellular telephone records incoming
voice messages which are retrieved and replayed by
users at their convenience. If the SAT signal is not
ls'lcllml‘iloilzlet al' '
3’740’488 ‘V1973 Lgltslildeetaél'
detected, call terminating circuitry immediately termi
nates call. In accordance with one aspect, voice mes»
3:7831384
sages may be recorded at the central cellular station in
V1974 wycoff .
‘ '
3,999,311 9/1975 Adler _
3,936,610 2/1976 Schiffman .
4/1976
3,958,235
5/1976 Duffy .
4,042,906
8/1977
reset
real time, subsequently transmitted to the voice storage
cellular telephone at a high speed and reproduced at
3,947,832 3/1976 Rosggn BI 21- - 1
3,950,607
P
Sout wort
normal speed to reduce air transmission time and cost.
eta. .
Ezell .
4,124,773 11/ 1978 Elkins ................................ .. 379/101
I .5
10 Claims, 16 Drawing Sheets
j l4
POWER
r I6
a
mono
SUPPLY
RECEIVER
‘2)
rneoueucv
5'6"“-
A9
x'
0500061
enamel} usssma
20V
ccnvsnrsa
swrrcmus,
(2:1) RESET Ann
CONTROL
/0 /Z’4
22-7
24 I
"EMORY
sumo
AMPLIFIER
/7
5,003,576
Page 2
U.S. PATENT DOCUMENTS
4,518,827
5/ 1985 Sagara ................................. .. 379/88
4,549,047 10/1985 Brian et a1.
2/1986
4,602,129
4,640,991
7/1986 Matthews et a1. .
2/1987 Matthews et a1. .
4,652,857
4,673,916
4,695,825
4,731,811
3/1987
6/1987
9/1987
3/1988
Dubus ................................. .. 379/58
340/825.44
4,742,560
5/1988
Arai . . . . . . . . . . . . .
455/38
4,763,207
8/1988 Podolak et a1. .
Armstrong ............................ .. 369/7
4,772,873
9/1988
4,264,898 4/1981 Barman et a1. .
4,356,519 10/1982 Cogdell, Jr. .
4,371,752 2/1983
4,408,099 10/1983
4,443,787 4/1984
4,468,813 8/1984
Matthews et a1. .................. ..
Ishii ................ ..
Denk et a]. ......................... ..
Burke et a1. ........................ ..
4,479,124
Rodriguez et al.
10/1984
379/88
4,573,140
4,495,647
1/1985 Burke et a1.
4,499,567
2/ 1985
379/88
379/57
341/11
455/38
Szeto ............. ..
364/900
379/88
379/88
Meiksin ............................... .. 381/31
Kitamura et a1. .
Bloy et a1. .
Duncan . . . . . . . . .
. . . .. 455/ 33
360/32
. . . . . . ..
341/ 110
U.S. Patent
POWER
SUPPLY
Mar. 26, 1991
sheet 1 of 16
‘5,003,576
AUDIO
DECODER
RECEIVER
FREQUENCY
ENABLEU MESSAGE
Y
/8'\_.
SIGNAL
CONVERTER
swrrcnms,
RESET AND
CONTROL
l0
22
241
MEMORY
FIG. I
CONTRO L LOGI C
CONTROL LOGIC
AUDIO
AMPLIFIER
US. Patent
Mar. 26, 1991
Sheet 2 of 16
‘5,003,576
US. Patent
Mar. 26, 1991
Sheet 7 of 16
/5
5,003,576
l5
5
TRANSMITTER
/
MESSAGE
RECEIVER
DECODING
MESSAGE MODULATION
RAM
II
/+
I
PLAYBACK
/7
s
CONTROL
TERMINAL
AMPLIFIER
i
FIG: 8
US. Patent
Mar. 26, 1991
Sheet 8 of 16
5,003,576
GS
>
\.36528 m2Eu3a0o2m
Ohsum12mmM0 0
m.ml
US. Patent
Mar. 26, 1991
mwri-Es?
Sheet 9 of 16
5,003,576
A
m23O0:u8w23E
D
1%
mwo
Aw
mZwu
%\
US. Patent
Mar. 26, 1991
Sheet 13 of 16
mum
u.lI
_I I
v
¢
Q
-_
_r
.u
5%\G9GEM3%_N\m,\
w
_
u
_
_
3
n
n
_
_
.
n
u
w
_
y
_
m
o
9n
_d
_
B
d
_
P
M
mdn
w
n
"
_
$58“a
_
_
_
A
s"
u5_o:032,»:
I}-\QR
_
_.l|
5,003,576
US. Patent
%\m.
Mar. 26, 1991
Sheet 14 of 16
5,003,576
US. Patent
I_III02.50
3.5 :
Mar. 26, 1991
I IV.
Sheet 15 of 16
5,003,576
US. Patent
Mar. 26, 1991
Sheet 16 0f 16
5,003,576
1
5,003,576
2
phone and to record a message for later playback. Al
ANALOG/DIGITAL VOICE STORAGE CELLULAR
TELEPHONE
though answering machines are readily available for
single-line use and their price is becoming more and
CROSS-REFERENCE TO RELATED
APPLICATIONS
able as part of the telephone circuitry itself. Most of the
existing answering machines are bulky and require a
substantial amount of desktop space. Furthermore, an»
swering machines are not readily available for multi
line business phones and com-line, cellular or mobile
more reasonable, such devices are normally not avail
This application is a continuation-in-part of copend
ing applications Ser. No. 110,002, ?led 10-19-87 now
abandoned, and Ser. No. 110,201, now issued as US.
Pat. No. 4,864,301, ?led on Oct. 19, 1987, each of which
recording.
is a continuation-in-part of copending application Ser.
No. 07/077,496, now issued as U.S. Pat. No. 4,905,003,
Also in the area of telephone communications, the
advent of cellular telephones has revolutionized mobile
?led July 24, 1987, entitled “ANALOG/DIGITAL
communications and has created a need for enhanced
DATA STORAGE SYSTEM.”
FIELD OF THE INVENTION
The present invention relates generally to the ?eld of
communication systems, and more particularly to a
capabilities. Cellular telephones utilize sophisticated
cellular technology and are faced with growing de
mand. Ongoing research in this area concentrates on
providing additional conveniences and reducing costs.
For example, presently, when a particular cellular user
is away from his or her unit, a general recording from
system for the conversion of analog signals to digital
signals for digital storage and for the retrieval and re 20 the central cellular station or site informs the caller that
conversion to analog format of such signals for play
the particular user cannot be reached at the time. Thus,
back. Most speci?cally the present invention relates to
the caller has to take the initiative of calling again,
an analog-to-digital voice storage cellular telephone,
which can result in several unavailing and frustrating
wherein messages are recorded when a user is away
attempts.
25
from the unit.
Most existing cellular telephones incorporate the
capability of indicating to users if they received any
BACKGROUND OF THE INVENTION
calls during their absence by some sort of an indicator.
This feature is sometimes useful and reassuring, espe
systems and radio-operated systems by which a message
cially when the user is expecting an important tele
can be left for an individual who is not able to be con 30
phone call from a particular person while away from
tacted directly for one reason or another. For example,
the unit. However, this feature is inadequate and does
many paging systems operate with a large complex
not solve the problem since it does not identify the
central processing facility in which messages are
caller, record the number at which the caller may be
queued and transmitted, normally in digital form, to
reached,
nor indicate the total number of callers and
subscribers, along with the subscriber’s address code.
their messages. Although answering machines for this
The subscriber to the service carries a paging unit
purpose are available for standard telephones, such
which is preprogrammed to activate upon receiving a
capabilities are not available with cellular telephones.
message which is preceded by the address code for that
Reducing costs is also another high priority since cellu
paging unit. The pager then normally emits an audible
lar
telephones are relatively expensive because calls are
sound to alert the subscriber that a message is being
typically billed on a per-minute basis.
received and recorded for him. The message is placed in
Yet another form of message service is the so-called
the pager memory and the message is retrieved in the
voice storage retrieval system (VMS) in which a voice
form of a written message, normally on an LED or
message can be left at a central message storage facility,
LCD display screen. Although such systems are ef?
and the subscriber, by use of a speci?c code, can access
cient and require very little air time in order to send the
The prior art is replete with various types of paging
digital message, the messages transmitted are necessar
ily of limited duration and are normally of the type
which require the subscriber to go to the nearest tele
phone and call the message originator. In addition,
the memory at the central computer to retrieve the
message. These systems are expensive to operate in
view of the necessity of powerful computers at the
central system facility to process and store the messages
unless the transmitted messages are strictly numeric, 50 and, in addition, can be inconvenient to use since the
subscriber must be at a telephone in order to receive the
message. In addition, messages may not be timely re
ceived because the addressee inadvertently fails to
check for messages.
systems of this type require expensive computerized
In the area of two-way radio communication, such as
55
central message facilities.
in the case of police and ?re communications, emer
Other paging systems are available which utilize a
i.e., telephone numbers and the like, alphanumeric mes
sages require a special terminal in order to input the
alphanumeric message to be transmitted, and paging
transmitter which transmits in analog form an audio
message preceded by an address code which is received
by a preprogrammed receiver. The message is played
immediately upon receipt, and, in some units, the mes
sage can be recorded on a tape cassette for replay. Pag
ers of this type are normally relatively bulky and re
quire substantially high power requirements to drive
gency communications and the like where the addressee
may be away from the mobile unit from time to time,
many systems employ the use of hand-held receivers,
i.e., walkie-talkies, which may be patched into the mo
bile receiver for the receipt of incoming messages while
the operator is away from the unit. Such devices are
expensive and, in many cases, would be totally unneces
sary if a reliable, inexpensive message storage system
the mechanical portions of the tape recorder.
In the area of telephone communications, typically 65 were available at the mobile unit. Some systems are
available answering machines have one or more tape
cassettes for playing a message to the caller to indicate
that the called party is not available to answer the
available which are similar to the telephone answering
machines for transmitting a prerecorded message and
for recording incoming messages when the operator is
3
5,003,576
not at the mobile unit. These systems have been found
4
to be bulky, unreliable and in?exible in connection with
radio communications.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is
A more sophisticated system has been promulgated in
provided an analog-to-digital data storage system
U.S. Pat. Nos. 4,468,813 to Burke, et al. and U.S. Pat.
No. 4,495,647 to Burke, et al. This system requires a
base unit which sends a command program packet in
digital form to the mobile unit which is programmed to
respond to the command program for receiving the
message in analog form. The command packet includes
numerous command codes, transmission of which re=
quire signi?cant air time. Responsive to the command
which is readily adapted for use in communication sys
tems such as paging systems, telephones, multi-line tele
phones, cellular telephones, intercom, message alarm
systems, telemetry systems, two-way radios and the
like, by which analog signals, including voice messages
and data transmission, can be received, converted to
digital format and stored in memory in digital format
for retrieval, reconversion to analog form and playback
as desired. In addition, the system permits suf?cient
program, the mobile unit converts the message to digital
form for storage and responsive to a termination com
mand sent in digital form by the base unit, the mobile
unit recording system is deactivated. The operator at
the mobile unit can then replay the digital message in
analog form. The system as disclosed in the aforemen
memory for dictation of messages for later playback or
transmission. The data storage system is easily installed
on existing telephone and radio equipment at low cost
and operates with very low power requirements. The
data storage system is adapted to be activated by any
conventional analog or digital address code such as, for
tioned U.S. patents requires a sophisticated encoding
example, digital code, tone, dual-tone multi-frequency
system at the base transmitter which is capable of gener
ating a command program packet and the termination
code signal. Furthermore, the base transmitter must be
(DTMF) or may even be voice activated (VOX). No
specially modi?ed transmitter is required for use with
the system of the present invention. In addition, the
means for deactivating the circuitry after receipt of a
capable of transmitting the command packet in the form
described in the aforementioned patents. The mobile 25 message is contained within the data storage system
itself and, except for an address code (which is pre
unit must be capable of receiving, decoding and trans
ferred but not critical), the necessity of transmitting a
mitting the command program packet back to the base
packet
of command data to control the reception and
unit. The mobile unit utilized in such systems requires
recording of the message at the receiving unit and a
two separate power supplies which would render the
termination code at the end of a message to deactivate
device unsuitable for portable hand-held receivers, such
the receiving unit is eliminated.
as pagers and the like.
In accordance with the present invention, the analog
In the communications ?eld, particularly in radio
to-digital data storage system includes receiver means
communications, transmission time is desirably main
tained at a minimum. In radio communication, the avail~
able channels are crowded and there is great competi
tion for air time. For this reason most paging systems
involve the transmission of messages in digital format
because the digital format requires less time to transmit.
for receiving an incoming signal carrying an analog
component from a suitable transmitter. The analog sig
nal is preferably preceded by a designated address code
which is speci?c to a particular data memory system.
The system further includes enable means activated by
the incoming signal to emit an enable signal (logic high)
The messages received, however, are limited to short 40 to activate the system circuitry, as will be hereinafter
written messages which are displayed on a small LED
or LCD display screen and the messages are normally
limited to the type that require the subscriber to go to a
described and illustrated. The enable means may com
prise a decoder which has been programmed to recog
nize an address code speci?ed to a particular receiver or
group of receivers. The enable means may also be acti
telephone and call the message originator. In addition to
the limited message capability of such systems, the 45 vated by the incoming signal without an address code,
such as in the case of a VOX circuit, to emit the enable
transmitting components are expensive, normally re
signal. The system also includes conversion means for
quiring centralized computer message facilities to trans
converting the incoming analog data to digital format
mit the digital data and to store the analog messages for
and memory means for storing the converted digital
the subscribers.
data. The conversion means further includes circuitry
Accordingly, it would be highly desirable to provide
for reconverting a digital signal to analog format. Con
a system for transmitting analog messages directly to a
trol means are provided for activating the conversion
remote unit in which the analog messages are transmit
means and the digital memory storage means responsive
ted at a high rate of speed to conserve air time and are
to the enable signal from the decoder means. In the
received and recorded at the remote unit for playback
at a slower rate of speed to return the message to its
audible condition. As a corollary, it would also be desir
able to transmit certain analog data at a slow rate of
speed and to play the message back at a higher rate of
speed, again to return it to its audible format. Such a
transmission procedure is bene?cially carried out in the
transmission of music and other high ?delity analog
data over telephone lines which normally adversely
affect the ?delity of the data being transmitted. In such
a case it would be desirable to transmit the data at a 65
slow rate of speed thereby to retain the ?delity and to
play it back at its normal rate of speed without loss of
?delity.
preferred embodiment, the control means also acts to
deactivate the conversion means and memory means at
the completion of the message or after a predetermined
period of time. Switching means are included for acti
vating the conversion means and the memory means for
playback in analog format of any stored messages. The
system further includes switching means for manually
activating the record and the playback modes, and am
pli?er means for listening to incoming analog signals
and playback of stored messages.
The system of the present invention is readily adapt
able for use with wire communication systems such as
single and multi-line telephone systems, intercom sys
tems, and for radio communication. Thus, the system of