JPH03135145A - Telephone set - Google Patents

Abstract

PURPOSE:To store the storage content by storing the storage content of a volatile memory into a nonvolatile memory when a voltage detected by a means detecting a backup power supply voltage reaches a specified value or below. CONSTITUTION:When a power failure lasts for a long time, the battery voltage is gradually decreased. That is, when the voltage is decreased to a voltage required to save the content of a RAM 6 onto a cassette tape, a voltage detection circuit 9e gives an ON command to a switch 9d, and a CPU 7 and a recording and reproducing circuit 3 are energized. Then the storage content is saved from the RAM 6 to the cassette tape in the circuit 3 by the control of the CPU 7 and then the storage content is stored semi-permanently even when a battery 9c is consumed out. On the other hand, when the power failure is recovered, the CPU 7 checks an output of the circuit 9e and confirms based thereon the save of the storage content from the RAM 6 to the cassette tape.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a telephone that semi-permanently retains the contents of volatile memory without increasing the capacity of the memory backup power supply. Regarding.

(Prior art) For example, in a telephone that can record an answering machine, a volatile semiconductor memory with a backup power source and a recording/reproducing circuit using magnetic tape are used in combination to record and reproduce voices, etc. .

If a power outage occurs in the regular power source (eg, commercial power source AC 100 V), the contents of the volatile semiconductor memory are retained by a backup power source such as a supercapacitor, a secondary battery, or a secondary battery.

However, in answering machines that use a backup power source to retain the stored content in non-volatile memory, if the regular power supply goes out for an extended period of time, the backup power supply voltage may drop and the stored content may be lost, or the stored content may be lost. If an attempt is made to increase the memory retention time as much as possible, the capacity of the backup power source must be increased, resulting in problems such as an increase in cost and a decrease in the smoothness factor.

(Problem to be Solved by the Invention) As mentioned above, in a telephone that uses a backup power source to retain the stored contents of volatile memory, if the regular power supply is out of service for a long time, the backup power supply voltage decreases and the stored contents are lost. Or, if you try to increase the memory retention time to avoid this, you have to increase the capacity of the backup power supply, which leads to increased costs and a decrease in the smoothness factor. .

This invention was made to solve the above-mentioned problems, and its purpose is to be able to semi-permanently retain the contents of volatile memory without increasing the capacity of the backup power supply. The aim is to provide a telephone that is designed to

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a telephone equipped with a volatile memory having a backup power source and a recording/playback circuit using a non-volatile memory. A detection means for detecting voltage, and when the voltage value detected by this detection means becomes less than a specified value,
The present invention is characterized by comprising means for storing the storage contents of the volatile memory in the nonvolatile memory.

(Function) According to this configuration, the storage contents of the nonvolatile memory are retained by the backup power supply in the event of a short power outage, as in the past, while the backup power supply is unable to supply power in the event of a long power outage. Before stopping, the stored contents are saved to non-volatile memory and are retained permanently thereafter.

(Embodiment) FIG. 1 is a block diagram showing the configuration of an embodiment of an answering machine to which the present invention is applied.

In the figure, an operation unit (referred to as OPE in the figure) 1 is composed of a numeric keypad or the like, and is used for inputting commands necessary for executing various functions provided in the telephone.

A display device (denoted as DISP in the figure) 2 is used to provide guidance on the state and operation of the answering machine during message recording or answering machine playback, which will be described later.

A recording and reproducing circuit (denoted as RECORD in the figure) 3 uses a cassette type magnetic tape as a recording medium to record and reproduce messages, voice mails, speed dials, and the like.

The wired line interface (LINE and memory in the diagram) 4 is
It provides an interface between the answering machine and a wired line (denoted as LIL2 in the figure).

A handset (denoted as HANDSET in the figure) 5 has a built-in handset.

The RAM 6, which is a volatile semiconductor memory, stores message contents, answering machine contents, speed dials, various data, and the like.

The CPU 7 includes the above-mentioned operation section 11 display 2. Recording and playback circuit 3. This is to centrally control the wired line interface 4 and the like.

Each of these elements 1 to 7 is connected to a regular power source (denoted as PS in the diagram).
8 is supplied with power, and RAM 6 and CPU
7 is a backup power supply (denoted as BACKPS in the diagram)
9 is possible.

Next, the general operation of this answering machine will be explained.

During a normal call, so-called 2-wire/4-wire conversion is performed by the action of the wired line interface 4, and then a call is made via the handset 5. Note that amplification by the speaker 10 is also possible if necessary.

When operating as an answering machine, the voice input as a message from the handset 5 is stored on a cassette tape in the recording/reproducing circuit 3 or in the RAM 6 via the wired line interface 4.

When there is an incoming call on the wired line (LIL2), the wired line interface 4 notifies the CPU 7 of this fact, and in response, the CPU 7 instructs the wired line interface 4 to close the line. Transfer already stored messages to cassette tape or RAM
6 and send it to the other party.

After sending the message, the other party's voice is recorded on a cassette tape or RAM 6, and when a certain period of time has elapsed or the conversation is ended, the recording is stopped and the contents are stored until a reproduction command is issued.

The display section 2 displays the status of the answering machine and provides operating instructions when recording a message or playing back the answering machine.
Correspondingly, the operator manually inputs a corresponding command from the operation unit 1.

Next, the backup operation of the RAM 6, which is the main part of the present invention, will be explained with reference to FIG.

In general, backup power sources include those that use a supercapacitor and those that use negative or secondary batteries, but in this example, a secondary battery is used.

As shown in the figure, this backup power supply 9 is connected to the common power supply voltage Vcc via a diode 9a and a resistor 9f.
The secondary battery 9c is charged with the voltage Vcc and starts supplying power to the RAM 6 when the voltage Vcc becomes equal to or less than the forward drop voltage Vf of the diode 9b.The output voltage of this secondary battery 9C is monitored, and when this becomes equal to or less than a specified value, the switch 9d is activated. The voltage detection circuit 9e turns on the voltage detection circuit 9e.

The output of the secondary battery obtained via the switch 9d is supplied to the recording/playback circuit 3, and is also supplied to the voltage detection circuit 9e.
The detection output is supplied to the CPU 7.

Here, the detection voltage of the voltage detection circuit 9e is set in accordance with the remaining battery level required to save the contents of the RAM 6 to the cassette tape in the recording/playback circuit 3, as shown in FIG. There is.

In other words, when the power outage becomes long, the battery voltage gradually decreases, and when the remaining capacity reaches the shaded area in Figure 3, that is, the voltage of the capacity required to store the contents of RAM 6 on a cassette tape. , switch 9 from voltage detection circuit 9e
An on command is issued to d, and power is supplied to the CPU 7 and the recording/reproducing circuit 3.

Then, under the control of the CPU 7, the stored contents are saved from the RAM 6 to the cassette tape in the recording and reproducing circuit 3, and thereafter, the stored contents are retained semi-permanently even after the battery 9c is exhausted.

It should be noted that if the power outage is for a short time, the battery voltage will not reach below the specified value, and in this case, the stored contents will be retained in the RAM 6 as in the past.

On the other hand, when the power outage is restored, the voltage detection circuit 9 in the CPU 7
Check the output of e, and based on this check the output of RAM6 during power outage
Check whether the memory contents have been saved to the cassette tape.

Here, if the stored contents have been saved, the CPU 7 restores the stored contents from the cassette tape to the RAM 6.

According to the above embodiment, when the power outage is short, the RAM
The stored contents of RAM 6 are retained by battery 9c, whereas if the power outage is for a long time, the stored contents of RAM 6 are evacuated to a cassette tape in recording/reproducing circuit 3 and retained semi-permanently.

Therefore, the battery 9c only needs to be capable of backing up short-term power outages, and does not require a large capacity battery.

Furthermore, when a long-term power outage is restored, the saved data in the cassette tape is automatically returned to the RAM 6.

Therefore, even when a long-term power outage is restored, the answering machine can resume operation in exactly the same way as when a short-term power outage is restored.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the contents of the volatile memory can be retained semi-permanently without increasing the capacity of the backup power supply.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an answering machine to which the present invention is applied, FIG. 2 is a diagram showing an example of a backup power supply, and FIG. 3 is a diagram showing the attenuation characteristics of battery voltage. DESCRIPTION OF SYMBOLS 1... Operation unit, 2... Display unit, 3... Recording/playback circuit, 4... Wired line interface circuit, 5... Handset, 6... RAM, 7... CPU, 8・・・
・Common power supply, 9...Backup power supply, 9e...
Voltage detection circuit, 10... speaker. Figure 2 (℃ Voltage Figure 3

Claims (1)

[Scope of Claims] A telephone equipped with a volatile memory having a backup power supply and a recording/playback circuit using a nonvolatile memory, comprising: a detection means for detecting the backup power supply voltage; and a voltage value detected by the detection means. 1. A telephone set comprising: means for storing the stored contents of the volatile memory in the non-volatile memory when the value of the volatile memory becomes less than a predetermined value.