JPS5868331A - Dial locking device of car telephone - Google Patents

Abstract

PURPOSE:To prevent a car telephone from being used without permission by setting its mobile equipment in a dial locked state wherein incoming is allowed and outgoing is disallowed through simple switch operation. CONSTITUTION:When the dial lock DL switch 84 of a telephone set 8 is pressed, a CPU81 converts its signal into a signal DL, which is sent to the CPU71 of a control part 7. The CPU71 writes a flag DL in an RAM74, and a lamp 82 is flashed through a display part driving circuit 76 to display a state DL, thereby sending a tone signal from a tone oscillator 77 to a receiver 83. When a reset code is inputted from a dial switch 85 to reset the state DL, the CPU81 sends it to the CPU71, which compares it with the contents of an ROM73 stored with a reset code to reset the flag in the RAM74 when they are coincident, stopping the operations of the circuit 76 and oscillator 77. When the device is disconnected from the battery and connected again and the power switch is turned on, the state DL is set by a signal from a battery break detecting circuit 75, so the telephone set is prevented from being used without permission.

Description

[Detailed description of the invention] It is something to do.

Conventional car phone mobile units could make calls at any time as long as the power switch was turned on. Therefore, if someone else uses a car equipped with a mobile phone,
The drawback was that even if a car phone was used without permission, the owner of the car phone would not know at all, and the owner would be billed for the use of the car phone.

In addition, even if a mobile phone is removed from a car in which it is installed, stolen, and installed in another car, it can be used immediately as long as it is connected to the mobile phone and the power switch is turned on. There was also a drawback.

In order to eliminate these drawbacks, the present invention provides a simple switch operation on the mobile phone terminal.
Dial lock state where calls can be received but cannot be made (hereinafter referred to as
This is simply called the dial lock state. ], the dial lock state will not be released unless a specific release code is entered, thereby preventing unauthorized use by anyone other than the owner, and even if the device is once removed from the notebook and then reconnected. The dial is automatically locked to prevent unauthorized use after theft.The drawings will be described in detail below.

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a mobile phone.

In Fig. 1, 1 is an antenna, 2 is a main body of the mobile device consisting of an antenna duplexer 3, a receiver 4, a local oscillator 5, a transmitter 6, and a control unit 7, and 8 is a telephone. Usually, the antenna 1 is installed outside the vehicle. The mobile device main body 2 is installed in a trunk room or the like, and the telephone 8 is installed in a suitable place in a car. In such a device, radio waves emitted from the base station are received by an antenna 1, received by a receiver 4 via an antenna common equipment 3, demodulated here, and sent to an &lIn section 7 to determine the channel to be used. is extracted, and the local oscillator 5 outputs a clock with a frequency tuned to the used channel to the receiver 4 and transmitter 6, and communication is performed by the telephone 8 through the control section 7.

When making a call from the mobile device side, when the handset of the telephone 8 is picked up, the control unit 7 causes the transmitter 6 to send out a call request signal using the calling channel, and the radio wave is transmitted via the antenna duplexer 3. A radio wave is transmitted from the antenna 1 toward the base station, and a radio wave specifying the channel to be used is sent back from the base station, and communication is performed in the same manner as described above. In this way, in the mobile phone of a car, the control and operation of incoming and outgoing calls are performed by the control unit 7 and the telephone set 8.

FIG. 2 is a detailed configuration diagram of the control section 7 and the telephone 8 according to the present invention. In FIG. 2, reference numeral 71 denotes a control unit 7 that controls the calling operation and other related parts when there is a request for dial lock state or a request for release.
side central processing unit (hereinafter referred to as CPU), 72
73 is a read-only memory (hereinafter referred to as %ROM) in which the operation program of the CPU7L is written, and 73 is a read-only memory in which a unique release code for each mobile device is written, which is required when releasing the dial lock state. Only memory (hereinafter referred to as ROM), 74 is a random access memory (hereinafter referred to as RAM) that stores whether the dial is locked or not, and 75 is a power switch for the entire device (not shown). ), the battery disconnection detection circuit detects whether there has been a disconnection between the battery ('N, source) and the device before that, and 76 drives the Sanjuji display section that displays the dial lock status. 77 is a tone oscillator that generates a low frequency signal to notify the dial lock state; 81 is a dial lock switch described later; and a telephone 8 side that receives signals from the dial switch and sends them to 0PU 71 and controls each part. cPU, 82 is a display unit that displays the dial lock state, for example a lamp, 83 is a receiver, 84 is a dial lock switch that requests setting to the dial lock state, and 85 is used as a code input switch for inputting a Δ release code. It is a dial switch that can be used to operate the power switch 174 and the battery disconnection detection circuit 75.The power supply for the intestine 174 and the battery disconnection detection circuit 75 is always supplied directly from the power supply, so that the contents are retained regardless of whether the power switch is turned on or off. Power is supplied to the circuit through the power switch.

Next, a method of operating the mobile phone of the mobile phone configured as described above and the operation of each part will be explained.

When the dial lock switch 84 of the telephone 8 is pressed (here, a momentary push-button switch that returns to its original position when the finger is released) is pressed, the 0PU as a signal processing unit is activated.
81 converts this into a dial lock request signal and sends it to the CPU 71 of the control section 7. C! When the PU71 receives this signal, the battery-backed RAM
The dial lock 7 lug indicating that the dial is in the lock state is set in the dial lock 74, and the display drive circuit 76 is controlled to blink the lamp 82 of the telephone 8 to indicate that the dial is in the lock state, and the tone oscillator is 7
7, when the handset 8 goes off-hook, the handset 83 is made to send out a tone indicating that it is in the dial lock state. In the dial lock state, the 40PU 71 is programmed in the ROM 72 so that the handset is off-hook and the 40PU 71 does not make a call operation. However, incoming call operation is possible.

Whether the dial is locked or unlocked depends on the FLAM being locked.
74, its state will not change even if the power switch is turned off. Therefore, even if the power switch is turned off while the dial is locked, the next time the power switch is turned on, the dial will be locked again.

To release the dial and lock state, a release code is input from the dial switch 85.

0PU81 gave this a C! Send to PU71. CPU7
When 1 receives this, the decryption code is written)
The content is compared with the contents of the LOM 73, and if they match, the dial lock flag in the RAM 74 is reset, the operation of the display drive circuit 76 and the tone oscillator 77 is stopped, and the state is made ready for making and receiving calls. When the code input from the dial switch 85 is different from the contents of the ROM 73, the dial lock state is not released.

Here, a dedicated push-button switch is used as the dial lock switch, but the dial switch 85 can also be used as a dial lock switch. It is also possible to use the dial lock switch and the code input switch, and it does not matter what is used as the dial lock switch or the code input switch. The dial lock state can be confirmed by the blinking lamp 82 of the telephone 8 and the oscillation sound from the receiver 83 when the handset is taken off-hook, and a person who does not know the dial lock release code cannot release the code and cannot make a call.

When the entire device is disconnected from the battery, connected again, and the power switch is turned on, the CPU 71 detects the above fact using the battery disconnection detection circuit 75, and displays the state before the entire device was disconnected from the battery. υThe dial is locked regardless of whether the dial is locked or released.

As mentioned above, there is no way to unlock the dial lock status other than inputting the old unlock code, so even if the mobile device is stolen while the dial lock is unlocked, there is no risk of it being used. .

An example of a specific circuit configuration of the battery disconnection detection circuit 75 is shown in FIG. In FIG. 3, 75a is a differentiating circuit consisting of a capacitor C and a resistor R, 75b is a flip-flop, and the input of the differentiating circuit 75a is directly connected to the car battery 9 via the power line 10. The output 1-171) is sent to the set terminal of the 275b. -7 Rig flop 75b Q output is 0
It is detected by PU71, and when the power switch is turned on, 0PU71 determines that the battery has been disconnected if the Q output is at /% low level, and sends a reset pulse to the reset terminal of dial b, and when the Q output is at low level. If so, it is determined that the battery is not disconnected, and it is determined whether or not to lock the dial according to the contents stored in R and AM74.

Next, the actual operation according to the time chart in FIG. 4 will be explained. Assume that the battery 9 is initially disconnected from the entire mobile device. At time 11, when the battery 9 is connected to the mobile device, its voltage drives the flip-flop 75b and is input to the differentiating circuit 75a via the power line 10.

Here, it is differentiated and becomes a pulse through the flip-flop 75b.
Set. When you turn on the power switch at the 12th point, %
0PU71 checks the status of the Q output of 7f70f75b, but in this case, since it is at a high level, it determines that there has been a disconnection, sets it to a dial lock state, stores this in 1'LAM74, and Reset the Rituzo 75b. After that, by inputting the release code, the dial lock state is released.

When the -H power switch is turned off at time 13 and turned on again at time t4, the CPU 71 checks the state of the Q output of the 7 Ritsuo Flotso 75b as described above, but in this case, since it is at a low level, it is determined that the battery is not disconnected. RAM74
It is determined whether or not to enter the dial lock state according to the stored contents.

This device makes the signal configuration of the dial signal sent from the telephone 8 to the control unit 7 by pressing the dial switch 85 and the signal configuration of the dial lock request signal sent by pressing the dial lock switch 84 common. This facilitates the processing of the CPU 71 on the control unit 7 side. FIG. 5 shows an example of the signal structure of a dial signal and a dial lock request signal, in which a 1-bit start bit ST and consecutive bits A, B, C,
Each of the four bits of D is transmitted in synchronization with an externally applied clock. Table 1 below shows the bit configuration of the signal corresponding to each getane.

Table 1 represents the lower level of logic. That is, normally it is a high level, and a start is indicated by going low, and after the start bit ST, A, B, O, D
Identification is performed using 4 bits.

The code for canceling the dial lock state is registered in advance by the owner at the time of contract for the car phone and is written in 1'LOM73, but if this code is not written, that is, the contents of ROM73 are 'all O'. In this case, the dial lock state may be controlled so that the dial lock state is not established regardless of the operation of the dial lock switch 84 or the disconnection of the gun.

As explained above, according to the present invention, the control section that controls the call origination operation in the mobile device of a car phone is put into the dial lock state by operating the dial lock switch, and the dial lock state is released uniquely to each mobile device. Since the device is not unlocked without entering the code, unauthorized use by anyone other than the owner can be prevented without interfering with incoming calls, and there is no risk of being charged a high call fee that the user is not aware of. In addition, if the entire device is disconnected from its power source, Nonotsute IJ-, when it is reconnected, the dial will be locked regardless of the state before disconnection, so there is no possibility that the stolen mobile device will be used by someone else without permission. can be prevented. Further, since the dial signal and the dial lock request signal have the same signal structure, there is an advantage that signal processing in the central processing unit can be easily performed.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a schematic diagram of a mobile phone mobile phone, FIG. 2 is a detailed diagram of the control unit and the parts of the telephone according to the present invention, and FIG. FIG. 4 is a time chart showing the operation of the battery disconnection detection circuit, and FIG. 5 is a signal configuration diagram of a dial signal and a dial lock request signal. 71... Central processing unit (CPU), 73... ROM for encryption writing, 74... Random access memory, 7
5...Battery disconnection detection circuit, 84...Dial lock switch, 85...Dial switch (code input switch)

Claims (1)

[Scope of Claims] (υ A dial lock switch for setting a mobile device of a car phone to a dial lock state in which calls can be received but cannot be made; a first memory that stores whether or not the dial is locked; a second memory that stores a release code for releasing the dial lock state; a code input switch that inputs the code; A central processing unit that performs signal processing to enter the dial lock state by operating the dial lock switch, and releases the dial lock state only when the release code from the code input switch matches the release code in the second memory. A dial lock device for a car phone, comprising: (2) a dial lock switch for setting a dial lock state in which calls can be received and calls cannot be made, and a first memory to which a stain source is directly supplied and stores whether or not the dial lock state is in place; A second memory in which a release code for canceling the dial lock state is written, a code input switch for inputting the code, and a dial lock by operating the dial lock switch according to the state of the first memory. A dial lock device for a car phone, comprising: a central processing unit that performs signal processing on the dial lock state and releases the dial lock state only when the release code from the code input switch matches the release code in the second memory; When the power switch is turned on, there is a disconnection detection circuit that detects that the entire device has been disconnected from the battery before then, and the central processing unit is in the dial lock state according to the detection signal of the battery disconnection detection circuit. A dial lock device for a car phone, characterized in that it performs signal processing for a car phone. (3) A dial lock switch for setting a dial lock state in which calls can be received but cannot be made, a first memory that is directly supplied with power from a battery and stores whether or not the dial lock state is in place, and a dial lock state. a second memory in which a release code for releasing the code is written; a code input switch for inputting the code; and signal processing to enter the dial lock state by operating the dial lock switch according to the state of the first memory. and a central processing unit that releases the dial lock state only when the release code from the code input switch matches the release code stored in the second memory, A dial lock device for a car telephone, characterized in that a dial lock request signal sent to the central processing unit based on an operation and a dial signal based on an operation of a dial switch have a common signal configuration.