WO1991012685A1

WO1991012685A1 - Multiple called-party telephone and answering machine system

Info

Publication number: WO1991012685A1
Application number: PCT/US1991/001009
Authority: WO
Inventors: Siew Khoon Lee; Ee Theow Lau
Original assignee: Siew Khoon Lee
Priority date: 1990-02-15
Filing date: 1991-02-14
Publication date: 1991-08-22

Abstract

A telephone and answering machine system for identifying the called party. The system stores codes identifying potential called parties, and associates each stored party code with a unique signal. The system prompts (via 15') for and decodes called party codes and issues the corresponding unique signal. The system can be further programmed to direct telephone calls to predetermined called parties to an integrally controlled answering machine (192) for the recording of messages. The system maintains an identification of each message that is recorded and the corresponding called party. Finally, the system provides for the selective play-back of recorded messages chosen based on a called party code given in conjunction with the command to play-back pending recorded messages.

Description

Multiple Called-Party Telephone and Answering Machine System

This application is a continuation-in-part of Serial Number 07/481,50?, filed February 15, 1990.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to telephony. More particularly, it relates to a telephone ringer which identifies the called party before the telephone is answered and provides a multiple called party answering machine function.

Description of the Related Art A standard telephone ringer provides an audible signal which indicates only that a caller has dialed the number of the given recipient telephone. This provides no information about, nor selectivity over, the identities of the caller nor the called party. Prior improvements in ringer technology have dealt only with identifying the caller, and excluding certain callers through "call blocking". The usual method, as disclosed in U.S. Patent No. 4,266,098 to Novak, is to assign each caller his or her own identifying code, which must be entered to connect his or her call. Calls from persons not entering a valid identifying code are not connected to the called party's telephone. To uniquely identify the sources of incoming calls, which may come from any of a very large number of a person's acquaintances, it is necessary to issue vast numbers of identifying codes. Thus, the prior improvements serve to provide the called party with information as to the identity of the caller, as well as to prevent unwanted calls.

However, it is also desirable to have information about the person whom the caller is calling, as the caller may wish to speak only with a given individual at a residence or business.

SUMMARY OF THE INVENTION Therefore, a general purpose of the present invention is to provide an integrated telephone and answering machine system for identifying called parties, for uniquely signalling the called party of the presence of a call, and for prompting for and recording a message where the called party is absent.

The system of the present invention stores codes identifying potential called parties, and associates each stored party code with a unique signal. The system prompts for and decodes called party codes and issues the corresponding unique signal. In a preferred embodiment of the present invention, the unique signal is a voice synthesized audible message. If no party code is entered or the code is not recognized as valid, the ringer issues a simulated telephone ringing sound rather than a voice synthesized audible message. The message identifies to whom the caller wishes to speak, so that non-called persons need not bother to answer the call; other persons need not physically go to the apparatus to determine the desired called party's identity.

The apparatus also provides means for keeping a list of potential called parties who are temporarily absent or otherwise unable to take calls. The system is programmable to direct telephone calls to predetermined called parties, typically absent called parties, to an integrally controlled answering machine for the recording of messages. The system maintains an identification of each message that is recorded and the corresponding called party. Finally, the system provides for the selective play-back of recorded messages chosen based on a called party code given in conjunction with the command to play-back pending recorded messages. Thus, an advantage of the present invention is that it allows for the selective, unique announcement of incoming telephone calls to parties who wish to receive telephone call .

Another advantage of the present invention is that it provides a mechanism for prompting for and recording messages directed to called parties that are absent.

A further advantage of the present invention is that it allows for the generic ring-through of calls to un-identifiable called parties, blocking of such calls, or for prompting for the recording of a message. Yet another advantage of the present invention is that it allows messages recorded for specific called parties to be played back with out the play back of messages left for other called parties.

BRIEF DESCRIPTION OF THE DRAWINGS These and other advantages and features of the present invention will become apparent when considered in conjunction with the following detailed description of the present invention and the drawings, wherein like reference numerals designate like parts throughout the figures thereof, and wherein:

FIG. 1 is a block schematic of the apparatus of the present invention; FIG. 2 is a circuit schematic of the detection module of the present invention;

FIG. 3 is a circuit schematic of the answer module of the present invention;

FIG. 4 is a heuristic flow chart diagram illustrating software state changes in the main operation of the present invention;

FIG. 5 is a heuristic flow chart diagram illustrating operation of the timer interrupt routine of the ringer software which issues the audio signals; FIG. 6 is a block schematic of the apparatus of the present invention;

FIG. 7 graphically illustrates a portion of a tape and a sequence of messages and tones recorded thereon; and FIG. 8 is a heuristic flow chart diagram illustrating the preferred software state changes in the operation of the present invention in capturing a message for an absent party.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Structure

The components of the apparatus of the present invention may be understood with reference to Fig. 1. The apparatus is a ringer 10, for connecting a telephone 102 to a telephone exchange 101 and for intercepting an incoming telephone call from the exchange 101. Lines 21 and 22 couple the ringer 10 to the exchange 101, and lines 21 and 23 couple the ringer 10 to the telephone 102. In the preferred embodiment, the ringer 10 is a separate module from the telephone 102, but could be built into the telephone^' 102 or a conventional telephone answering machine, within the scope of this disclosure.

A. Micro-controller

The ringer 10 is driven by a micro-controller 13, which executes routines to provide all logic functions of the ringer 10. A suitable micro-controller 13 is that sold by Motorola Corp. under part number "MC68HC05". Within the micro-controller 13 are memory 17 for storing melodies, and memory 16 for storing party codes and passwords. In one embodiment, the melody memory 17 stores ten different melodies and the memory 16 stores ten different party codes (one for each numerical key '0' through '9' on a conventional telephone keypad), and one password for each party code, but other compliments are obviously feasible. The micro-controller 13 also includes memory 19 for storing a list of absent-party codes, and a counter 18 for timing operations of the ringer 10.

The micro-controller 13 is coupled serially through a resistor 41 and a capacitor 43 to line 21, on which the ringer 10 sends signals 205 to the exchange 101. The micro-controller 13 is coupled to a switch bank 20, which contains manually user-setable switches for controlling various logical functions of the ringer 10. In one embodiment, the switch bank 20 contains four switches. The first switch 121, when set on, puts the ringer 10 into a programmable state for assigning passwords and for entering party codes into the absent-party list. The second switch 122, when set, enables the ringer 10 to screen incoming calls via a password protocol. The third switch 123, when set, puts the ringer into its normal operational mode of playing a melody in response to entry by a caller of a valid party code. The fourth switch 124 disables the ringer 10 and couples the telephone 102 directly to the exchange 101.

The ringer 10 also includes a fifth switch (not shown) which, when set, causes the ringer to play a fixed melody every time a call arrives when the ringer is switched on and the telephone is not off-hook, regardless of the entry by the caller of any party code which would otherwise trigger the selection of a given melody from the plurality of stored melodies. This feature is intended for use in an office or other setting where multiple telephones are operated in close proximity. By setting each ringer to play a different melody, the office personnel can determine which phone is being called even without being near that phone. Each extension's ringer may be set to play a different melody, so personnel will not tush to their phones if a call is for someone else. In the preferred embodiment, the fifth switch is a logical switch within the software controlling the ringer 10.

B. Detection Module

The ringer 10 has a detection module 11 which detects an incoming ringing signal 202 from the exchange 101, and detects the on-hook or off-hook status of the telephone 102. As shown in Figs. 1 and 2, the micro-controller 13 is coupled to the detection module 11 by input lines 27 and 28, which the micro-controller 13 interrogates, enabling the micro-controller 13 to perform logic functions according to the arrival of an incoming ringing signal 202 and according to the on-hook or off-hook status of the telephone 102. The detection module 11 has transistors 51 and 52, which have collector leads coupled, via pull-up resistors, to the ringer's power source 44 (VCC), and emitter leads coupled to the ringer's power reference or ground 70 (VSS). The base leads of the transistors 51 and 52 are coupled to lines 22 and 23, respectively. Line 22 is coupled to the exchange 101, and line 23 couples the detection module 11 to the conventional receiver hook switch (not shown) inside the telephone 102.

The micro-controller 13 is also coupled to the detection module 11 by output line 29. In a manner determined by its logic functions, the micro-controller 13 sends a signal 209 to the detection module 11 on line 29 to cause the detection module 11 to couple line 22 to line 23, in order to connect the telephone 102 to the exchange 101. The detector module 11 is coupled to the answer module 12 by lines 24 and 30 to facilitate on- hook detection.

c Answer Module

The details of the answer module 12 can be understood with reference to Figs. 1 and 3. The micro-controller 13 is coupled to the answer module 12 by output line 26. According to the signal 206 from the micro-controller 13 on line 26, the answer module 12 can be directed to answer the incoming call on lines 21 and 22. The answer module 12 is also connected to the detection module 11 by line 24 to detect placement of the telephone 102 on-hook, and by line 30, which couples the solid state relays 53 and 56.

When the micro-controller 13 detects ringing via the detection module 11, it sends a low logic signal 206 on line 26 to enable the solid-state relay 56 and an opto-coupler 57. Activation of the relay 56 presents an off-hook condition to the telephone exchange 101 on line 21 through line 22, maintaining an active connection to the exchange 101. Submodule 12-1 provides a high impedance AC load and a low impedance DC load. Line 24 is connected to line 21 to enable on-hook detection. Line 26 may be set high by the micro-controller 13 to switch off the DC load on the telephone line 22. D. Melody Module

The micro-controller 13 is coupled to a melody module 15 via digital output lines 33 and 34, which carry the melody signals 203 from the micro-controller 13 to the melody module 15. In one embodiment, melody module 15 may be a conventional piezoelectric transducer, which converts the melody signals 203 into audible sounds. An alternate embodiment of the melody module 15 includes a conventional amplifier and speaker.

E. DTMF Module

The micro-controller 13 is coupled to a dual tone modulated frequency (DTMF) module 14 on bus 35. A suitable DTMF module 14 is available from Silicon Systems, Inc., under Part No. "SSI 204". The DTMF module 14 is coupled to line 21 across the resistor 42 and the capacitor 43, to detect dual tone frequencies from the local telephone 102 or from a remote telephone on the exchange 101. Dual tone signals are generated by the keys of a conventional touch-tone telephone. The DTMF module 14 decodes any arriving dual tone signal and provides the micro-controller module 13, on bus 35, with a signal 235 indicating the binary coded value of the key pressed to generate the dual tone signals. In one embodiment, bus 35 may be a parallel five-line digital bus.

F . Message Reorder Module

The micro-controller 13, as shown in Fig. 6, is provided with an electrical interface suitable for controlling a conventional cassette tape recording system including conventional record, play, fast forward, reverse and erase controls and further including a motor 194, enabled via signal on line 198 from the micro-controller 13, to drive a conventional cassette tape gear unit 192. Micro-controller 13 also controls a solenoid 196 via control signal provided on line 400 for selecting the mode of operation of the gear unit 192. Cassette tape reels 190 are, in turn, driven by the gear unit 192 for driving a tape 188 engaged with a record/playback head 186. The micro-controller 13 receives a number of signals for controlling the operation of the message recorder module. These signals include a mode signal 150 which indicates whether the tape 188 is in contact with the record/playback head 186, an end-of-tape signal 152 derived from the operation of gear unit 192 and signifying an end-of-tape condition, and rewind and fast forward control signals 154, 156 for managing conventional aspects of the operation of the message recorder module. The micro-controller 13 preferably controls a voice synthesizer control unit 15' via a number of message selection control signals and operation enable control signals provided via lines 158. The message output by the voice synthesizer 15' is provided on a line 160 that is coupled through a capacitor 43' to the phone line 21 to allow the calling party to receive messages.. This message may be also routed through an analog switch 170 to an output amplifier 178 via line 176. The amplified message is driven on line 180 to a external speaker 182 so that the message may be heard locally. An output line of the micro-controller 13 is coupled through a resistor 41 to a node 162 that is further coupled through a resistor 166 to ground. By digitally switching the state of the output line from the micro-controller 13, a very simple digital-to- analog conversion of the signal is accomplished. This pseudo analog signal is coupled to through a capacitor 43 onto the phone line 21 and through a resistor 164 to an input of an analog circuitry unit 404. The signal generated by the micro-controller 13 may simulate a busy signal for provision back to the calling party where the called party code is invalid, for example.

The signal generated by the micro-controller 13, in a preferred embodiment of the present invention, also includes a constant frequency tone in the range of 300 to 750 Hz, though preferably fixed at 500 Hz. This tone is provided to the input of the analog circuitry unit 404 for transfer onto the tape 188 as a marker delimiting messages recorded ©n the tape 188. The analog circuitry unit 404 incorporates the conventional analog circuitry necessary to implement a record and playback function, receiving an input signal originating with either the phone line 21 or micro¬ controller 13 and providing an output signal on line 406. A bidirectional line 184 couples the record/playback head 186 to the analog circuitry unit 404. Thus, the input signal may be recorded onto the tape 188, while a playback signal from the tape 188 can be output onto the line 406, through an analog switch 410 and to an amplifier 178 so as to be audibly reproduced by the speaker 182. The analog switch 410 and 170 may be independently controlled via control signals provided on line 174 from the micro-controller 13.

Finally, a tone detection circuit 412 is coupled via a line 172 to the output of the analog circuitry unit 404. The tone detector unit 412 is tuned to detect a constant audio signal that corresponds to the preferred 500 Hz signal recorded on the tape 188 during normal record mode and persisting for a duration in excess of 0.25 to 4 seconds, preferably set for a period of 2 seconds. The tone detector unit 412 is also capable of detecting the constant audio signal that corresponds to the 500 Hz tone when the tape 188 is in fast reverse or fast forward mode. That is, the tone detector is tuned to also detect any constant frequency in a range of 500 to 2000 Hz. Thus, the tone detector 412 is easily capable of distinguishing the preferred 500 Hz tone during both ordinary playback and during fast forward and reverse operation. Human speech, by its inherent nature, will not produce a fixed tone for any duration approaching that necessary to trigger the tone detector unit 412.

Fig. 7 provides a graphic illustration of a segment 440 of the tape 188 provided with multiple messages 442, 444, 446, 448 delimited by end-of-message markers 450_x, 450_x+1, 450_x+2, 450_x+3. On initializing a new tape 188, an initial message marker 450 is placed on the tape. Thereafter, messages are recorded sequentially with an appended end-of-message marker 450. The playback of selected messages is accomplished by having the micro-controller 13 store, in internal RAM, a list of the called party identification code associated with each message 442, 444, 446, 448 for at least those messages that have not been previously retrieved. Micro-controller 13, when requested to playback messages directed to a specific called party that have not been previously retrieved, directs operation of the message recording module to rewind the tape 188 counting back the end-of-message markers 450 until the appropriate message, 442 for example (marker 450_x) , is reached. The message 442 can then be played back at normal speed and, upon detection of the end-of- message marker 450_x+1, micro-controller 13 can determine to playback the next message 444, skip forward to the message 446, or fast forward to the last end-of-message flag 450 by counting forward the remaining number of end-of-message markers 450. In this manner, a single tape 188 can be utilized to store any number of messages directed to any number of called parties, limited as a practical matter to the available amount of RAM, recording tape, and the delay to seek to any particular message on the tape 188. In a preferred embodiment of the present invention the micro-controller 13 tracks messages for four independent called parties.

ii. Operation

A. incoming Telephone Call

1. Rinσinσ

The operation, of the ringer 10 upon the arrival of an incoming telephone call can be best understood with reference to Figs. 1 and 2. The incoming call has an AC ringing signal 202 which is intercepted by the detection module 11. The ringing signal 202 will alternately turn on the transistors 51 and 52 by alternately forcing line 22 higher than line 23 and vice versa.

However, if the telephone 102 is off-hook, one transistor 51 or 52 will be turned on and will remain in the on state. The micro-controller 13 polls lines 27 and 28 to detect ringing and to detect the off-hook status of the telephone 102. If lines 27 and 28 carry opposite signals 207 and 208 and alternate, ringing is determined to be present. However, if lines 27 and 28 carry opposite signals and do not alternate, the micro-controller 13 determines that the telephone is off-hook. The particular conventional wiring scheme employed by the telephone exchange 101 and the telephone 102 will determine which exactly one transistor 51 or 52 is turned on by the off-hook condition of the telephone 102. However, the micro-controller 13 merely compares the signals 207 and 208 on lines 27 and 28, and does not depend upon either particular transistor 51 or 52 to indicate off-hook. This allows the ringer 10 to be used in a variety of countries without modification.

When ringing or off-hook occurs, the micro-controller 13 is reset. After being reset by an incoming ringing signal 202, the micro-controller 13 continuously polls lines 27 and 28 to wait for an off-hook condition. However, if the reset was caused by an off-hook condition, the micro-controller 13 continuously polls lines 27 and 28 to wait for an on-hook condition. After either form of reset, the resistor 47 prevents additional resets from occurring until the micro-controller 13 performs a stop-mode routine.

2. Answering

If ringing is detected, micro-controller 13 will send a signal 206 to the answer module 12, by switching line 26 low. This serves as an answer-back signal to the telephone exchange 101, to signal the exchange 101 to terminate the ringing signal 202.

3. input of Party Code The micro-controller 13 sends a prompting signal 205 through the resistor 41 and the capacitor 43, to line 21, indicating that the caller is to provide a party code. In one embodiment, the prompting signal 205 is a musical melody, but in other embodiments it can be a simple tone or a digitized voice message. The caller may then provide a party code 201, which, in one mode, is the DTMF tones generated by a single key press of a touch-tone telephone, wherein a party code of "1" indicates that the caller wishes to speak to party number 1, party code "2" indicates party number 2, and so forth.

4. Party Code Provided If the caller provides a party code 201, the party code 201 is received by the DTMF module 14, which decodes the dual analog frequencies generated at the key press of the party code 201, and converts them to a digital party code 235 which is sent to the micro-controller 13 on bus 35 as a binary coded digit. The micro-controller 13 compares the digital party code 235 to each of the party codes stored in the party code memory 16. In one mode, the party codes are stored as embedded logic within the logic of the micro-controller software, so that no physically separate memory is required to store the stored party codes and so that lookup of a party code received from the caller merely involves checking whether the received party code is between "0" and "9" inclusive. If the digital party code matches one of the stored party codes, the micro-controller 13 looks up the matching party code in the absent-party list memory 19. a. Invalid or Absent Requested Party

Three states may exist at this point. If 1) the digital party code did not match any stored party code, then a simulated "ringing signal" sound will be generated. Preferably, the "ringing signal" sound is sufficiently distinctive to alert other persons at the called party's location that the calling party has not correctly entered a party code, but still desires to speak with someone at the called party's location.

If 2) there was a match, but the matching party code was found in the absent-party list, no called- party melody will be played and, in the one embodiment, the micro-controller 13 will send to the caller a signal 215 indicating that the call cannot be connected. In this embodiment, the signal 215 may be a simulated "busy signal" sound. However, in the presently preferred embodiment of the present invention, where an invalid party code was entered, the signal 2IS is a simulated ringing signal that is audiable at the called party location. Where the called party is absent, the signal 215 provided to the caller will indicate that the called party is absent and that the calling party may leave a message by responding with an appropriate signal. In the preferred embodiment of the present invention, the signal represents the key press of the pound (#) key, whereupon the micro-controller 13 directs the operation of the message recording module to begin recording. The micro-controller 13 terminates the recording of a message, after determining that the originating phone has been placed on-hook, by first recording a fixed frequency tone, preferably 500 Hz, for a predetermined period of time, preferably 2 seconds in duration. Operation of the motor 194 is then halted.

b. Valid and Non-absent Requested Party However, if 3) the digital party code matched a stored party code which was not found in the absent party list, the micro-controller 13 looks in the party code memory 16 to determine which melody in the melody memory 17 is associated with that party code. The micro-controller 13 generates signals 203 according to that melody. The signals 203 are presented at two digital output pins of the micro-controller 13, and are provided on lines 33 and 34 to the melody module 15, which converts the signals 203 into an audible melody to alert the called party. The generation of the signals 203 can best be understood with reference to Figs- 1 and 5. Melodies are generated by variably switching the binary value of each line 33 and 34 of the micro-controller's output port at the desired frequencies. Micro-controller 13 creates the AC frequency signals 203 which represent the desired melody, by toggling lines 33 and 34 from high to low and low to high at given intervals of time, such that during melody play, lines 33 and 34 will, at any given instant, carry opposite binary values. This is accomplished by controlling the Timer Interrupt Routine 314.

A counter 18 within the micro-controller 13 marks the intervals of time by counting down from specified numbers. When the counter 18 reaches the end of the count, an interrupt occurs and the Timer Interrupt Routine 314 is invoked. The Timer Interrupt Routine 314 toggles the lines 33 and 34, and primes the next interrupt by loading the appropriate value into the counter 18. Higher values take longer to count, and thus correspond to longer periods between toggling of lines 33 and 34, and therefore represent lower output melody frequencies.

After priming the counter 18, Timer Interrupt Routine 314 also provides a five-millisecond window for the software to use before returning to the location of the interrupt. The software uses this window to perform various housekeeping tasks while the Timer Interrupt Routine 314 generates the next frequency to be required in the melody. When the melody ends, both lines 33 and 34 are switched off, so the melody module 15 will not see a voltage difference across lines 33 and 34.

5. Party Code Not Provided As will be understood with reference to Figs. 1 and 2, if no party code is provided within a given amount of time, the micro-controller 13 generates a signal 203 on lines 33 and 34. Melody module 15 converts this signal 203 into an audible signal to alert all parties of the arrival of an incoming telephone call not directed to any given party. In one mode, the audible signal simulates the ringing sound of a conventional telephone. This audible signal alerts all persons present that the caller has not entered a party code. The persons may deduce that the caller is not familiar enough with them to know how the ringer 10 operates, and may choose to answer or ignore the call. In a preferred embodiment, this audible signal may be muted to minimize disturbances of persons present at the called location and to be distinguishable from the ringing of standard telephones.

6. Called Party Answers Telephone If a valid, non-absent party code is entered by the caller, a voice message or melody will be played as described above. When the called party hears his or her message or melody, he or she may lift the telephone receiver. The hook switch of the telephone 102 will then provide the off-hook signal on line 23. As soon as the micro-controller 13 detects the off-hook condition via the detection module 11, the micro-controller 13 issues a signal 209 on line 29, to enable the solid-state relay 53. Enabled solid-state relay 53 couples line 22 to line 23, thereby connecting the telephone 102 to the exchange 101. The micro-controller 13 will switch off the melody signals 203 on lines 33 and 34, to terminate any playing melody. Once the solid-state relay 53 is enabled, both the transistors 51 and 52 will switch off, terminating the detect signals 207 and 208. Line 24 will carry a high voltage (48 volts) from the exchange 101 through the zener diodes 54 and 55 when the telephone 102 is placed back on-hook, then one transistor 51 or 52 will turn on again, signalling the micro-controller 13, which then switches off the solid-state relay 53 and lowers line 26, and returns to a stop-mode state.

B. Outgoing Telephone Call

When the telephone 102 is picked up, or taken off-hook, in the absence of any incoming ringing signal 202, the off-hook signal on line 23 will turn on one transistor 51 or 52, which signals the micro-controller 13 of an off-hook condition. This resets the micro-controller 13, which will, after polling lines 27 and 28 and detecting the off-hook condition, switch line 29 low to enable the solid-state relay 53, to connect the telephone 102 to the exchange 101. The micro-controller 13 will then continuously poll the detection module 11 on lines 27 and 28, to wait for on-hook at the end of the call. When the receiver returns on-hook, the micro-controller 13 returns to its stop-mode state.

III. Operation of the Micro-controller Software Routines A. Incoming Call l. R nging Fig. 4, together with Fig. 1, illustrates the operational state changes of the ringer of the present invention. An incoming call will reset the micro-controller, which jumps immediately to an Initiation Routine 301. The Initiation Routine 301 clears and presets the various memories, timers, counters, and I/O registers internal to the icro-controller. Execution then jumps to a Detection Routine 302 to determine whether the reset was caused by an incoming call's ringing or by an off-hook telephone. 2. Answering If ringing is detected by the Detection Routine 302, execution branches to a Ring Answer Routine 303, where the ringer answers the call. After the call has been answered, execution branches to a DTMF Detection Routine 304. 3. Input of Party Code

The DTMF Detection Routine 304, when executed, prompts the caller for a party code, then waits for one to be sent. A Timer Routine 306 runs in parallel with the DTMF Detection Routine 304, and determines the amount of time the DTMF Detection Routine 304 will wait for a party code.

4. Party Code Provided a. Invalid or Absent Requested Party If a party code is detected within the time allowed, the DTMF Detection Routine 304 compares the received party code to the stored party codes to determine whether it is a valid party code. However, if the second switch 122 is set on, the caller must enter the password associated with the party code, rather than the party code itself, to provide an added level of protection from unwanted calls. This has the added affect of greatly ensuring that callers that do not know a valid party password are identified by the ringing sound only, and not incorrectly as a result of a random keyed party code. If the party code or password is valid, the DTMF Detection Routine 304 compares the party code (or that associated with the password) to the stored absent-party codes to determine whether the requested party is absent.

If the party code or password is either invalid or is indicated as being that of an absent party, a Melody Play Routine 305 is invoked to issue a message informing the caller that his party code was invalid or his requested party is absent. In one preferred embodiment, this signal may be a simulated "ringing signal" for invalid party codes audible at the called location.

In the preferred embodiment, a digitized voice message is issued when the called party is recognized as absent. As shown in Fig. 8, a Message Prompt Routine 475 is executed to issue a message asking whether the calling party desires to have a message and, if so, to press the pound (#) key. The DTMF module 14 will recognize this keypress, if issued, and execution will continue with a Message Record Routine 476. In all other instances, the Stop Mode Routine is then executed. The micro-controller 13, in executing the Message Record Routine 476, engages the tape 188 in conventional record mode and then polls the status of the on-hook signal on lines 27, 28. When an on-hook condition is recognized, the micro-processor 13 produces an end-of-message marker signal that is recorded onto the tape 188.

Execution then continues at a Stop Mode Routine 307. In all instances discussed herein, Stop Mode Routine 307 disconnects the call, if not already disconnected, and takes the micro-controller into a low power consumption mode, or "sleep state". b. Valid and Non-absent Requested Party

However, if a valid party code or password is entered, and is not found in the absent party list by the DTMF Detection Routine 304, the Melody Play Routine 305 is invoked to issue the message or play the melody associated with the requested party. The Timer Routine

306 is executed in parallel with the Melody Play Routine

305, as well. If the Timer Routine 306 determines that a given amount of time has expired without the called party answering the call, execution branches to the Stop

Mode Routine 307.

5. Party Code Not Provided If the Timer Routine 306 determines that a given amount of time has passed without the caller providing a party code, the Melody Play Routine 305 is invoked to play a signal, preferably a simulated "ringing signal, indicating the arrival of a call Without a called party code.

The Timer Routine 306 is executed in parallel with the Melody Play Routine 306, to determine whether a given amount of time has expired without the called party answering the call. If the time expires without the call being answered by anyone, execution branches to the Stop Mode Routine 307. 6. Called Party Answers Telephone

However, if a valid, non-absent party was requested, and the receiver is lifted before the allotted time expires, execution branches to the Off-hook Routine 308 which connects the telephone to the exchange and waits for the receiver to be returned on-hook at the end of the call. When the telephone is hung up, execution passes to an On-hook Routine 312. The On-hook Routine 312 determines the amount of time the telephone is on-hook. If the telephone remains on-hook for more than a moment, the On-Hook Routine 312 passes execution to the Stop Mode Routine 307.

However, if the telephone is quickly taken back off-hook, the On-hook Routine 312 places the call on "hold" and execution is passed to the Off-hook Routine 308, which invokes a second DTMF Detection Routine 311. The second DTMF Detection Routine 311 waits to detect the entry of a party code, which may be a keypress of a numeric key at the local telephone. When the key is pressed, the second DTMF Detection Routine 311 passes execution back to the Off-hook Routine 308 with an indication of which key was pressed.

The Off-hook Routine 308 invokes a second Melody Play Routine 309 to play the melody indicated by the numeric key pressed. In this manner, a call may be "transferred" to a different called party. Execution then continues at the Off-hook Routine 308, as described above for a normally answered call. A second timer routine (not shown) runs in parallel with the second Melody Play Routine 309, in case the new, transferred party does not answer the call, similar to the parallel execution of the first Melody Play and Timer Routines 305 and 306.

B. Outgoing Call

After a reset and execution of the Initiation Routine 301, if the Detection Routine 302 detects an off-hook condition, execution branches to the Off-hook Routine 308, which subsequently passes control to a Dial -25-

Control Routine 313 for dialing. After dialing is complete and the call is connected, execution branches back to the Off-hook Routine 308 to await the end of the call, and execution continues as described above for incoming calls.

C. Ringer Programming

In order to perform programming of the ringer 10, the first switch 121 of Fig. 1 must be manually placed in the "set" position. Programming is needed for entering password codes and for placing party codes in the absent-party list. In one embodiment, no programming is necessary for setting the stored party codes nor for associating them with the stored melodies, since the logic software within the micro-processor 13 sets the ten possible party codes and ten stored melodies to correspond to single keypresses of the ten numerical keys ('0' to '9' ) of the conventional touch-tone telephone, respectively. The press of the '1' key as a party code will, therefore, result in the ringer playing melody number 1; party code '2' results in melody 2; and so forth.

The ringer 10 will store one password code for each party code. In one embodiment, each password code consists of one to four digits generated by numerical keypresses. The password codes are not fixed by the micro-controller's logic software, but are set and changed by the users of the ringer 10. When the first switch 121 is set, execution cycles between the Off-Hook Routine 308 and the Memory Input Routine 310 of Fig. 4. In the preferred embodiment, the ringer 10 issues one beep at each keypress during programming, to inform the programmer that the keypress was accepted. upon successful completion of a programming instruction, the ringer 10 beeps twice, and upon detection of a programming error, the ringer 10 beeps three times.

The seguence of the star key ('*'), followed by one to four numerical keys, the star key again, and finally another single numerical key, is used to program a password for a given party code, as illustrated in Table 1:

TABLE 1: Password Programming Keys fieSV.lt

*123*1 Melody 1 and party code 1 are assigned the password "123". *4567*2 Melody 2 and party code 2 are assigned the password "4567". *0000*1 Melody 1 and party code 1 now have no assigned password. Code 0000 is used to delete any prior entry.

The absent-party codes are programmed in a somewhat similar manner, using the pound key ('#') instead of the star key, as illustrated in Table 2:

TABLE 2: Absent-Party Code Programming

Keys Resul

#1#7 Party code 1 is placed in location

7 of the absent-party list. #2#7 No result, as location 7 of the absent-party list is already occupied by party code 1. The ringer beeps three times to indicate the programming error, . and party code 2 is not placed in the absent-party list.

#4#8 Party code 4 is placed in location

8 of the absent-party list. #0000#7 The party code in location 7 is removed from the absent-party list. Code 0000 is used to clear a location in the absent-party list, regardless of which party code may have been there, if any.

The ringer 10 may be set to play a fixed melody. Location 1 in the absent-party list is a software "switch", reserved for storing a party code selecting the fixed melody, as shown in Fig. 3:

TABLE 3: Fixed Melody Programming

Keys Result

#4#1 The ringer is set to play melody 4. #0000#1 The software "switch" is cleared. No melody is fixed, and the ringer operates normally.

If location 1 of the absent-party list is not cleared to '0000', an incoming or transferred call to the ringer's extension will result in the playing of the melody whose party code is stored in location 1.

Remote play back of recorded messages can be accomplished by entering a star ('*' ) and then the password of the called party whose messages are to be replayed. The micro-processor 13 directs the rewind of the tape 188 to the first message that has not be replayed for the selected called party. The messages for that called party are then replayed, skipping all other messages. Once the last message has been replayed, the microprocessor issues a tone to the caller to signify the end of the messages. The tape is then fast forwarded to the last occurrence of a end-of- message marker. While the invention has been described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes may be made in the form and detail thereof, without departing from the scope and spirit of this disclosure.

Claims

CLAIMS We claim:

1. An apparatus for identifying a called party out of a plurality of callable parties located in a first area by a calling party located in a second area, said apparatus comprising: a) means for transmitting voice and control signals bidirectionally from said second area to said first area, said transmitting including first and second terminal receiver means, respectively coupled to said transmitting means in said first and second areas, for originating and receiving voice and control signals; b) receiving means, coupled to said transmitting means, for receiving said control signals directed to said receiver means located in said first area, said receiving means including, i) input means for receiving a called party identifying control signal, ii) means, responsive to said called party identifying control signal, for selecting an identifying signal out of a plurality of identifying signals, and

• iii) means for providing said identifying signal, independent of the operation of said transmitting means in transmitting voice and control signals, in said first area.

2. The apparatus of Claim 1 wherein said receiving means further includes: means for prompting said calling party for said called party identifying control signal.

3. The apparatus of Claim 2 wherein: said means for transmitting in said second area comprises a telephone; said means for prompting comprises means for providing to said telephone in said second area an audio signal audible to said calling party.

4. The apparatus of Claim 1 wherein: each said identifying signal comprises a unique audio melody; and said means for providing said identifying signals comprises means for making the melodies audible to any of said callable parties present in said first area.

5. The apparatus of Claim 4 wherein said apparatus further comprises: digital memory for storing a logical representation of said melodies,^• a digital micro-controller having digital output ports coupled to said means for making the melodies audible, and including logic for toggling data values at said output ports to control said means for making according to the stored logical representation of a given melody.

6. The apparatus of Claim 1 wherein: said called party identifying control signal comprises a dual tone modulated frequency signal such as is generated by a touch-tone telephone keypress; and -31- said input means comprises a means for accepting and decoding dual tone modulated frequencies and generating therefrom a decoded signal representing said dual tone modulated frequencies.

7. The apparatus of Claim 6 wherein: said means for selecting comprises a digital micro-controller coupled to receive said decoded signal from said means for decoding, said micro-controller being responsive to said decoded signal to, i) select a given identifying signal from said plurality; according to a value of said decoded signal, and ii) operate said means for providing said identifying signal in accordance with the given selected identifying signal.

8. An apparatus for use in receiving a telephone call from a caller to a called party, said apparatus comprising: first means for storing a plurality of party codes, and for storing a plurality of signals, and for associating each stored party code with a unique stored signal; second means for detecting and answering said telephone call; -' third means, coupled to said second means for detecting, for accepting a party code from said caller; fourth means, coupled to said third means for accepting and to said first means for storing, for i) comparing said accepted party code to said stored party codes, for ii) indicating a condition responsive to said comparing, said condition being a match condition if said accepted party code matches any stored party code or a non-match condition if said accepted party code does not match any stored party code, and for iii) identifying, upon a match condition, which stored party code matches said accepted party code; and fifth means, responsive to said fourth means for comparing, for issuing, upon a match condition, the given unique stored signal which is associated with the identified party code.

9. The apparatus of Claim 8, wherein each said unique stored signal comprises: an audio melody.

10. The apparatus of Claim 8, wherein each said party code comprises: dual tone modulated frequencies such as are generated by a touch-tone telephone keypress.

11. The apparatus of Claim 8, wherein: said first means for storing further comprises means for keeping a list of absent-party codes; said fourth means for comparing further being responsive to said means for keeping, such that if said accepted party code matches an absent-party code in said liεt, said condition indicated by said means for comparing will be an absence condition; and said fifth means for issuing does not issue said given unique stored signal in response to said absence condition.

12. The apparatus of Claim 11 wherein: said apparatus issues to said caller, in response to said absence condition, a signal indicating said absence condition.

13. The apparatus of Claim 12, wherein: said signal indicating said absence condition is a simulated busy signal.

14. A method of receiving a telephone call from a caller to a called party at a terminal telephone, said method comprising the steps of: storing a plurality of party codes; storing a plurality of signals; uniquely associating each stored party code with one stored signal; detecting and answering said call; accepting a party code from said caller; comparing said party code to said stored party codes; indicating a condition responsive to said comparing step, said condition being a match condition if said party code matches any stored party code or a non-match condition if said party code does not match any stored party code; identifying, upon a match condition, which stored party code matches said party code; and issuing, upon a match condition, the given unique stored signal which is associated with the identified party code.

15. The method of Claim 14, wherein each said stored signal comprises: an audio melody.

16. The method of Claim 14, wherein each said party code comprises: a touch-tone telephone keypress.

17. The method of Claim 14, wherein: said step of storing said party codes further comprises the step of keeping a list of absent-party codes; said comparing step further comprises looking up said party code in said list and indicating whether said party code is in said list; and said issuing step is further conditional upon said looking up step indicating that said party code is not in said list.

18. A ringer apparatus for answering a telephone call from a caller's telephone, said call having a ringing signal (202) and arriving on a telephone exchange, and for forwarding said call to a terminal telephone (102) having on-hook and off-hook states, said terminal telephone having a hook switch providing an off-hook signal in response to said off-hook state, said ringer apparatus comprising: first means (21,22) for coupling said apparatus to said exchange; second means (21,23) for coupling said apparatus to said terminal telephone; detection means (11), coupled to said first and second means for coupling, for detecting said ringing signal and for providing in response thereto a ring detect signal (207,208), and for detecting said off-hook signal and for providing in response thereto an off-hook detect signal (207,208); first storage means (16) for storing a plurality of party codes; second storage means (17) for storing a plurality of audio signals; controller means (13), coupled to said detection means and said second means for coupling, for controlling logical operation of said ringer apparatus, and for issuing, responsive to said ring-detect signal, an answer signal (206), and for uniquely associating each party code stored in said first storage means with one signal stored in said second storage means; answer means (12), coupled to said first means for coupling and to said controller means, for establishing a connection of said ringer apparatus to said exchange, responsive to said answer signal; means (14), coupled to said second means for coupling and to said controller means, for receiving a party signal (201) from said caller, and for sending a party code (235) to said controller means indicating a value of said party signal; comparator means, within said controller means, for matching said party code against said stored party codes, and responsive to said matching, for indicating a match condition if said party code matches any party code and a non-match condition if said party code does not match any party code, said match condition including identification of which party code matches said stored party code; signalling means (13,15), responsive to said match condition, for issuing the signal which said controller means uniquely associates with the party code identified by said match condition.

19. The ringer apparatus of Claim 18, wherein: said ringer apparatus further comprises means (19) for keeping a list of absent-party codes; said comparator means further being for matching said party code against said list of absent-party codes; and upon said party code matching any absent-party code in said list, said comparator means indicating an absent condition and not a match condition, said signalling means not issuing signals in response to absent condition indication.

20. The ringer apparatus of Claim 18, wherein: said answer means further provides a prompting signal to said caller to prompt said caller to provide said party signal.

21. The ringer apparatus of Claim 18, wherein said off-hook signal is a DC signal, and said ringing signal is an AC signal, said ringer apparatus being connected to a power supply (VCC) and a power reference (VSS), wherein said detection means comprises: first (27) and second (28) logic output ports; first (51) and second (52) transistor means for providing digital logic, said first and second transistor means each having an emitter lead coupled to said power reference, and a collector lead coupled to said power supply; said collector leads of said first and second transistors further being coupled to said first and second logic output ports, respectively; said first transistor means further having a base lead coupled to said exchange to receive said AC signal and coupled to said emitter lead of said second transistor, such that alternating half-cycles of said AC signal generate alternating opposite logic signals at said output ports; said second transistor further having a base lead coupled to said telephone to receive said DC signal to provide said second logic signal at said second output port only, whereby said DC signal generates non-alternating opposite logic signals at said output ports; said alternating opposite logic signals comprise said ring detect signal; and said non-alternating opposite logic signals comprise said off-hook detect signal.

22. A detection apparatus (11), for use with, and coupling to, a telephone which provides a DC signal indicating the on-hook or off-hook condition of a handset of said telephone, and for use with, and coupling to, a telephone exchange which provides an AC ringing signal indicating an incoming telephone call, said detection apparatus comprising: a VCC power supply and a VSS power reference; first (27) and second (28) logic output ports; first (51) and second (52) transistor means for providing digital logic, said first and second transistor means each having an emitter lead coupled to said VSS power reference, and a collector lead coupled to said VCC power supply; said collector leads of said first and second transistors further being coupled to said first and second logic output ports, respectively, whereby each said output port carries a first logic signal if the respective transistor to which it is coupled is off; said first transistor means further having a base lead coupled to said exchange to receive said AC ringing signal and coupled to said emitter lead of said second transistor, such that, i) a high half-cycle of said AC ringing signal will turn said first transistor on and said second transistor off, to provide said first logic signal and a second logic signal at said second and first output ports, respectively, said second logic signal being logically opposite of said first logic signal, ii) a low half-cycle-of said AC ringing signal will turn said firsJ» transistor off and said second transistor on, to provide said first and second logic signals at said first and second output ports, respectively, iii) alternating half-cycles of said AC ringing signal thereby generating alternating opposite logic signals at said output ports; and said second transistor further having a base lead coupled to said telephone to receive said DC signal, such that said DC signal will turn said second transistor on without turning said first transistor on, to provide said second logic signal at said second output port only, whereby said DC signal generates non-alternating opposite logic signals at said output ports.

23. An apparatus providing for the controlled delivery of a telephone call message from a calling party to a called party, said apparatus comprising: a) means for intercepting telephone calls; b) means for announcing called parties; c) means for recording messages; d) means for controlling said intercepting means, said announcing means, and said recording means, said controlling means enabling„the interception of a telephone call by ξ,said intercepting means, said controlling means including means for determining an identification of the called party and determining whether said identification corresponds to an absent called party, said controlling means controlling said announcing means for announcing the called party corresponding to said identification, said controlling means including means for coupling said recording means to said intercepting means for the transfer of a telephone call message to said recording means, said controlling means controlling the operation of said recording means to enable the recording of said telephone call message provided by the calling party.

24. The apparatus of Claim 23 wherein said controlling means includes means for providing a delimiting signal to said recording means for recording at the conclusion of said telephone call message, said controlling means being coupled to receive a signal from said intercepting means for determining the conclusion of said telephone call message.

25. The apparatus of Claim 24 wherein said recording means includes tape means for sequentially recording messages, head means for recording and play back of messages and delimiting signals and means for fast forwarding and reversing the relative location of said head means with respect to messages recorded on said tape means, wherein said controlling means includes means for storing said identification with respect to said telephone call message and the number of messages sequentially recorded by said recording means on said tape means relative to the sequential recorded location of said telephone call message, and wherein said controlling means includes means for detecting the occurrence of said delimiting signal during the fast forwarding and reversing of said head means with respect to messages recorded on said tape means.