# US 5,706,340 A · Telephone apparatus including circuit for producing dial data from serial key data

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- Number: US 5,706,340 A
- Document ID: US5706340A
- Status: Granted
- Kind: A
- Application number: 08/358,760
- Filed: 1994-12-19
- Granted: 1998-01-06
- Earliest claimed: 1993-12-22
- Assignees: Rohm Co., Ltd.
- Inventors: Mitsuro Saji
- Web page: https://patentgrep.com/patent/US5706340A

## CPC

- H04M 1/00: Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08)
- H04M 1/30: Devices which can set up and transmit only one digit at a time
- H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08)

## Abstract

A serial data generating circuit and a key input signal generating circuit are provided at a panel substrate side, and input key data are transmitted in series to a main substrate side of a telephone apparatus. The number of signal lines connected between the panel substrate and the main substrate are reduced. Further, on the main substrate side downstream of a selection circuit, a data converting and producing circuit which converts the serial input key data into parallel dial data is provided to permit switching of the signal source between a processor and the panel substrate to thereby enable a dial call origination even during a power failure condition.

## Claims

### Claim 1

A telephone apparatus comprising:
a keyboard including ten keys and symbol keys;
a serial data generating circuit which generates serial input data corresponding to inputted keys on said keyboard in response to clock pulses;
a key input signal generating circuit which generates a key input signal representing an input through a key in response to a signal from said keyboard;
a panel substrate provided with said serial data generating circuit and said key input signal generating circuit and disposed at the side of an operation panel;
a clock generating circuit which generates the clock pulses;
a processor which receives the clock pulses, the key input signal and the serial input data, and outputs serial key data and control signals in parallel with the serial key data, wherein said serial key data and said control signals are produced in response to the serial input data and the clock pulses, or in response to the serial input data and other pulses that are generated in response to the clock pulses;
either a dial pulse generating circuit or a dual tone multi frequency signal generating circuit;
a selection circuit which receives the clock pulses from said clock generating circuit, the key input signal or a signal corresponding the key input signal, the serial input data, and the parallel output signals from said processor; outputs, in parallel with each other, the parallel signals from said processor during normal operation; and outputs, in parallel with each other, the clock pulses from said clock generating circuit, the key input signal or the signal corresponding to the key input signal, and the serial input data during a power source interruption;
a data converting and producing circuit which produces dial data from the output signals received from said selection circuit;
a main substrate provided with said processor, either said dial pulse generating circuit or said dual tone multi frequency signal generating circuit, said selection circuit, and said data converting and producing circuit;
wiring through which the clock pulses, the key input signal, and the serial input data are inputted in parallel with each other to both said selection circuit and said processor; and
a power source circuit which supplies electric power from a telephone line to either said dial pulse generating circuit or said dual tone multi frequency signal generating circuit, said clock generating circuit, and said data converting and producing circuit on said main substrate and the panel substrate.

### Claim 2 (depends on 1)

A telephone apparatus according to claim 1, wherein one of the control signals corresponds to the key input signal, and said selection circuit receives, in parallel with each other, the parallel output signals from said processor at a first set of input terminals thereof, and further receives, in parallel with each other, the clock pulse from said clock generating circuit, the key input signal, and the serial input data at a second set of input terminals, and during normal operation outputs, in parallel with each other, the inputs at the first set of input terminals and during power source interruption outputs the inputs at the other set of input terminals.

### Claim 3 (depends on 2)

A telephone apparatus according to claim 2, further comprising a power source interruption detecting circuit which detects a power source interruption and sends out the detection signal to said selection circuit to switch the connection therein to the second set of input terminals, and an initiation circuit which initiates one of said dial pulse generating circuit and said dual tone multi frequency signal generating circuit, wherein said power source interruption detecting circuit, said initiation circuit, and said clock generating circuit are provided on said main substrate, said initiation circuit is initiated by said data converting and producing circuit; and a wiring through which the clock pulse from said clock generating circuit is transferred to said panel substrate.

### Claim 4 (depends on 2)

A telephone apparatus according to claim 2, further comprising a power source interruption detecting circuit which detects a power source interruption and sends out the detection signal to said selection circuit to switch the connection therein to the second set of input terminals, and an initiation circuit which initiates one of said dial pulse generating circuit and said dual tone multi frequency signal generating circuit, wherein said power source interruption detecting circuit, said initiation circuit, and said clock generating circuit are provided on said panel side substrate; and a wiring through which the clock pulse from said clock generating circuit is transferred to said main substrate.

### Claim 5 (depends on 1)

A telephone apparatus according to claim 1, further comprising a display device provided on said panel side substrate; and a wiring which is designed to send out an output data from said processor to said display device therethrough, provided between said main substrate and said panel side substrate.

### Claim 6 (depends on 5)

A telephone apparatus according to claim 5, further comprising a controller at said panel side substrate; wherein said processor is constituted primarily by a CPU, and wherein said CPU upon receipt of the key input signal sends out the clock pulse and a read control signal to control said controller, receives the serial input data in response to the clock pulse, and sends out the clock pulse and a write control signal to said panel side substrate to control the controller, and sends out display data for said display device to said panel side substrate.

### Claim 7 (depends on 6)

A telephone apparatus according to claim 6, further comprising a transit circuit which during the normal operating condition receives the key input signal and the serial input data from said panel side substrate, passes and sends out the key input signal and the serial input data to said CPU, receives the read control signal, receives the write control signal and the display data from said CPU, and passes and sends out the read control signal, the write control signal, and the display data to said panel side substrate, wherein said selection circuit sends out the signals passing through said transit circuit to said data converting and producing circuit during a power failure.