JPH01105620A - Electronic circuit device - Google Patents

Abstract

PURPOSE:To prevent an electronic circuit device from being stolen by making it not turn into a normal operating state by only supplying power, unless the same code as an identification code, stored in the electronic circuit device previously, is inputted, when it is detected that the input of power supply has been cut off. CONSTITUTION:The device is provided with a sound output inhibition circuit 8, a control input part 19 to be used for inputting the identification code, and the back-up power source 22 of the memory of the identification code, etc., stored in a control part 16. The control part 16 decides whether a voltage exists at INT shown in a figure, and if 'vehicle + B power source' is disconnected, the control part 16 holds a sound output inhibiting circuit at an inhibitation state, unless at the time of the switch-on of the power, supply, numerals corresponding to the identification code are inputted from the control input part 19 and are displayed on a display 21, and collation with the previously stored identification code is attained. Such the inhibitation state is canceled if the input correct within the range of the identification input mistake of more or less ten times, for instance, is inputted.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to electronic circuit devices, particularly electronic circuit devices including radios and recording/playback devices installed in passenger cars, for example, under special circumstances. The present invention relates to an electronic circuit device that can enter a normal operating state only when a password code matches when the power is turned on.

(Prior Art) Although the present invention is not limited thereto, there are cases where an electronic circuit device installed in a passenger car or the like is removed from the car and stolen. As a method for preventing such theft, there has conventionally been a method of mechanically locking the electronic circuit device to a dash board or the like. However, this method has drawbacks such as a complicated structure and high cost, and the dash board and the like can be destroyed and even stolen.

(Problems to be Solved by the Invention) As described above, even if a conventional electronic circuit device is stolen, it can operate normally if power is supplied again.
Mechanical locking methods had their limitations.

An object of the present invention is to provide an electronic circuit device that solves this problem, and in which a PIN code input into the code input means in response to power-on and a PIN code previously given in the electronic circuit device. An electronic circuit device that operates normally only when the code matches the code, and can be re-entered at least once or more times even if a mistake is made in entering the PIN code;
Moreover, it is an object of the present invention to provide an electronic circuit device in which inputting a password is necessary in case of theft but does not normally require inputting.

(Means for Solving the Problems) In order to achieve the above object, the electronic circuit device of the present invention has the following features:
A cutoff detection means for detecting whether or not a power supply input is cut off; and an operation state prohibition means for disabling a normal operating state of the electronic circuit device when the cutoff detection means detects that the stain deep input has been cut off. It is constructed such that a password is input by a code input means, and when the power is turned on, the password entered into the code input means and the password previously given in the Nariko circuit device are input. The codes are compared, and if they match, the prohibition process by the driving state prohibition circuit is canceled, and if they do not match, the code can be input again at least once or more times.

(Function) By detecting whether or not the power input is interrupted and whether or not the password code matches, the electronic circuit device will not operate normally if it is stolen. Additionally, the verification of the PIN code can be repeated multiple times, and if you make a mistake in entering the code, you can re-enter the code.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the processing mode of an embodiment of the control section shown in FIG. 1.

In FIG. 1, 1 is an antenna, 2 is a high frequency amplification circuit,
3 is a mixer circuit, 4 is a voltage controlled oscillator in a PLL circuit and corresponds to a local oscillator, 5 is an intermediate frequency amplifier circuit, 6 is a detection circuit, 7 is a stereo separation circuit, 8
9 is an output amplification circuit, 10.11 is a speaker, 12.13 is a magnetic head, and 14. is an audio output prohibition circuit prepared in the present invention, which corresponds to the operating state prohibition circuit according to the present invention. 15 are equalization amplifier circuits, 16
17 is a low-pass filter constituting the PLL circuit; 18 is a prescaler that extracts a tuned frequency when receiving FM; 1
Reference numeral 9 is a control input section which is used for inputting a pin code, etc., 20 is a display driver for Fi display, 21 is a display that displays, for example, the FM tuning frequency in numbers, and 22 is a memory backup power source. The vehicle +B power supply, which is used to secure the power supply for the memory for the password code etc. held in the control unit 16, represents the power supply of a passenger car or the like.

Assuming that the audio output prohibition circuit 8 is in the non-inhibited state in normal operating conditions, the broadcast waves from the antenna 1 are transmitted to the circuit elements 2, 3, 4, 5° 6.7.8 (non-inhibited) as is conventionally known. state) w 9 t 1o , 11 and output as audio output by the speaker 10.11.

In addition, the heads 12, 13,
The output from the amplifier 14.15 is output by the speaker 10.11 to the audio output inhibition circuit 8t- which is in the non-inhibited state.

Under normal operating conditions, it operates as described above, but for example, in a set for Europe, the FM tuning frequency when receiving FM is configured to be displayed as a 6-digit number on the display 21. . That is, when the output frequency of the voltage-controlled oscillator 4 is controlled by the control unit 16, the frequency that is in the tuning state at that time is picked up by the prescaler 18, and the control unit 16 controls the driver 20 to set the tuned frequency. It is configured to display numerically on the display 21.

In the case of the present invention, as an example, the display 21
Focusing on the existence of a tuned frequency light indicating function,
It is used to enter the PIN code mentioned above.

In other words, when the electronic circuit device is installed,
First, set to FM reception mode, select a specific tuned frequency on the display 21, and input numerical information corresponding to the tuned frequency into the control section 16 by key operation from the control input section 19. make it memorized. It should be noted that for inputting the personal identification code using the numerical display of the tuning frequency, for example, a number of about 680 υ can be given, which can be considered to be a number that does not cause any problem in practical use.

As mentioned above, assuming that the PIN code has been memorized once, for example, under special operating conditions as explained with reference to FIG. The control unit 16 keeps the audio output prohibition circuit shown in FIG. 1 in the prohibited state unless the code is correctly verified against the previously stored password. For example, if the password is entered incorrectly within the range of about 10 times, this prohibited state will be resolved if the password is entered correctly, but if the password is incorrectly entered more than 10 times, only a person with special authority can do so. Unless the reset circuit 23 activates the process known to the user, that is, the reset function by the reset circuit 23, the prohibited state will not be canceled and the power will be turned off or the like.

FIG. 2 shows an embodiment of processing related to password input in the control section.

When the power is turned on, in this state, if the PIN code is not stored in the device as described above, the illustrated route (4
), and the password code FO is stored in a form that corresponds to the predetermined tuning frequency as described above. At the time of memorization, l'-YESJ is displayed on the display 21, and the normal operating state is entered. That is, it is possible to operate it arbitrarily whether it is radio reception or recording/playback. If the power is turned off and then turned on again in this state, the following will occur. That is, this time, the route shown in Figure 2 (B
), and it is checked whether or not the "vehicle width 10B power supply" shown in FIG. 1 has been cut off under some circumstances.

That is, it is checked whether the electronic circuit device is being driven once it has been removed from the vehicle. Whether the mosquito repellent has been removed or not is determined by the bank up power supply 22 shown in Figure 1.
The control unit 16 receives energy from I as shown in the figure.
For example, whether or not there is voltage on the NT and whether the electronic circuit device is installed at a predetermined equipment position on the passenger car is determined by a switch or the like and stored. "
If the "vehicle 10B power supply" is not cut off, the vehicle can continue along the illustrated route (B) and enter the normal driving state.

However, if the "vehicle + B power supply" is disconnected,
For example, the operator displays a specific tuning frequency on the display 21 in the same way as above, and then presses the control input section 1.
From 9 onwards, it becomes necessary to give a verification instruction. In other words, proceed to step (C) shown in FIG. If the input code F and the previous password code F match, the normal operating state is entered. However, if there is a mismatch, the electronic circuit device is allowed to re-enter 10 times, and if the input is still incorrect, the electronic circuit device is put into an unusable state by, for example, turning off the power.

Note that storing the above-mentioned PIN code, determining that it is installed on the vehicle, verifying the PIN code, and generating control output for the driving state prohibition circuit can be easily performed by simply incorporating an extremely small processor. It is possible.

(Effects of the Invention) As explained above, according to the present invention, it is possible to detect whether or not the power supply input has been interrupted, and when it is detected that there has been an interruption, the password code given in advance to the electronic circuit device is Since the electronic circuit device does not enter the normal operating state unless the same code is entered through the code input means, even if it is stolen, it will not operate normally just by supplying power, so it is highly effective in preventing theft. . Furthermore, when installed in a vehicle, there is no need to enter a personal identification code each time, so it is not inconvenient to use. Additionally, even if you make a mistake in entering your PIN code, you can re-enter it a certain number of times, making it incredibly practical. Furthermore, the structure is simpler and less costly than mechanical locking methods.

[Brief explanation of the drawing]

FIG. 1 shows the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the processing mode of an embodiment of the control section shown in FIG. 1. In the figure, 8 is an operation state prohibition circuit, 16 is a control section,
19 is a control input section, 21 is a display, 22
represents memory backup power supply. Figure 2

Claims (1)

[Claims] In an electronic circuit device configured to shift to a normal operating state in response to power on, there is provided a cutoff detection means for detecting whether or not a power input has been cut off, and whether the power input has been cut off by the cutoff detection means. The device includes an operating state inhibiting means for disabling the normal operating state of the electronic circuit device when the electronic circuit device is detected, and is configured to input a PIN code by the code inputting means, and inputs the code in response to power-on. The PIN code inputted by the means is compared with the PIN code given in advance in the electronic circuit device, and if they match, the prohibition process by the driving state prohibition circuit is canceled, and if they do not match, the code input is at least An electronic circuit device characterized in that it is configured so that it can be redone one or more times.