JPH02299945A - Burglar preventing device for audio device mounted on car - Google Patents

Abstract

PURPOSE:To improve a burglar preventing effect by a method wherein during disconnection of a backup source, input of a memory code is demanded, when the inputted code does not coincide with a set code, an audio device is brought into a motion prohibiting state, and the reinput of a code can not be effected unless otherwise the procedure of given control is taken. CONSTITUTION:When a power source is turned ON, it is discriminated by a control block 1 whether a backup source is connected. When the backup source is disconnected even once, display is all left lighted OFF, and a state to demand input of a memory code is produced. For example, preset channel selection keys M1 - M6 for radio are used as a code input means. When a memory code (four digits) is inputted, it is compared with a set memory code. When the two codes coincide with each other, a display device 5 is brought into normal radio display, and a radio and a cassette can be used. Meanwhile, during erroneous input, receipt of reinput of a code is prohibited, but when input of four digits is completed, reinput is practicable by pressing an ST key for a given time (approximate three seconds).

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention includes a code setting section for anti-theft, a code input section, and a comparison control means for comparing the input code and the set code. The present invention relates to an anti-theft device for in-vehicle audio equipment.

B. Conventional technology Conventional anti-theft devices for in-vehicle audio equipment use a microcomputer, store a password in its built-in or external memory, and operate the audio equipment for the first time after theft is detected. The system involved manually entering a PIN code, and when a match was made, each function of the sound device was activated.

Japanese Patent Application Laid-open No. 104434/1983 discloses such an anti-theft device for in-vehicle audio equipment.

C1 Problems to be Solved by the Invention In the above-mentioned prior art, if the PIN code is entered incorrectly, it is allowed to be re-entered several times, and if the PIN code is incorrectly entered, the code entry is not accepted for a certain period of time. The attempt was made to prevent unauthorized users who do not know the correct PIN code from accidentally entering the correct PIN code. However, with this method, you can enter the code repeatedly if you take the time, so the correct pin code will be revealed before long.

D6 OBJECT OF THE INVENTION An object of the present invention is to provide an anti-theft device that allows only a user who knows the correct password code to re-enter the code.

E6 Means for Solving Problems The present invention provides an anti-theft code input means, an anti-theft code setting means, detects that the backup power supply is turned off, and outputs the code only when the power supply is closed after the detection. A backup power supply detection means for requesting an input, an operation prohibition means for prohibiting normal operation of the audio equipment when the code input is requested, and a comparison between the input code and the code set by the code setting means, and comparing both of them. a comparison control means that cancels the operation prohibition state only when the input code and the setting code match, and a comparison control means that prohibits re-input of the code when the input code and the setting code do not match as a result of the comparison, and a predetermined operation means. The present invention is characterized by comprising: a code input prohibiting means for detecting a predetermined operation different from a normal operation and allowing re-input of the code.

When the F6 action code input key is pressed by mistake, re-input of the code is permitted by performing a predetermined operation different from the normal operation of the specific operation means announced together with the correct password.

G. EXAMPLES The present invention will be explained in more detail below using examples with reference to the drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a block diagram showing the configuration of an anti-theft device for in-vehicle audio equipment according to the present invention, in which 1 is a control block;
is an operation key matrix, 3 is a diode switch, 4 is a battery, 5 is a display, 6 is a cassette block, 7 is a tuner block, 8 is an audio signal switch, 9 is L
Represents ED.

The apparatus shown in FIG. 1 operates as follows.

When the power is turned on, the control block 1 determines whether the backup power source is connected or not, and if the backup power source is continuously connected while the power is turned off, the control block 1 does not require the input of the PIN code. , it becomes normal radio or tape operation.

If the backup power supply is disconnected even once, all displays remain smokeless, the radio does not operate, and the audio signal switch 8 is forcibly switched to the radio side, so no audio is output, and the control block 1 will ask you to enter your PIN code.

Here, the password is 4 digits, and is set as a combination of numbers 1 to 6, for example, to use the M1 to M6 keys, which are radio preset channel selection keys, as code input means. Each 4-digit PIN code is determined by a diode switch. For example, if only D0 in the figure is connected and D~D are not connected, the PIN code is '
2431'.

When entering the password, the digits and numerical values are determined in sequence depending on the order in which the M1 to M6 keys are pressed. To enter the above password manually, press the M2 → M4 → M3 → M1 keys in sequence. At this time, the display 5 shows 2 #, % 4', % 3g.
, % 1 g, will light up in sequence. The control block 1 compares the password code set by the diode switch 3 with the input code, and in the above case, since they match, the display 5 changes to a normal radio display and the radio or cassette tape function is enabled. Become.

If the code is entered incorrectly, the code entry will not be accepted even if the M1 to M6 keys are operated again.

However, by pressing the ST key (stereo/monaural switching key) for 3 seconds or more after completing the four-finger input, the four-digit display disappears and re-input is possible.

The original owner of the device is notified along with the correct PIN code that re-entry is possible by special operations on specific keys other than the M1 to M6 keys, so the original owner cannot enter the code incorrectly. You can re-enter it even if you do.

However, other people do not know how to re-enter the code, and since it is a special operation, it is unlikely that they will notice it by accident, so if the code is entered incorrectly the first time, it is impossible for the device to operate normally.

Further, in order to notify that the device has an anti-theft function, by pressing the ST key while the power is off, the LED 9 at the rear of the display 5 flashes.

To cancel this blinking, press the ST key for 2 seconds or more.

Although the case where the ST key is used has been described above, the operation key is not limited to the ST key.

Of course, any other key may be used as long as it is unrelated to the operation currently being executed.

Which key is used depends on the microcomputer program.

FIG. 2 is a flowchart summarizing the above-mentioned operation. In the "initial setting", the display and control signals are initialized. In "Backup?", it is determined whether the backup power supply was continuously connected when the power switch was turned on, and "Password capture from the diode" is performed.
The password code is determined by turning on/off the diode switch. Furthermore, in the "Password match?" field, the value entered manually at "Password input" is compared with the password input from the diode switch.

If there is a mismatch, did you press the next rST key for more than 3 seconds? '', it is checked whether a special re-input operation has been performed, and unless it is performed, it will not return to ``Password Manually''.

The effects of the above embodiments include the following.

i) Since the PIN code is entered using the M1 to M6 keys on which numbers are displayed, there is no need to search for keys when entering a multi-digit code. Furthermore, since the numerical values and order of the operated keys are recognized as the numerical values and digits of the PIN code, the time and effort required to enter the code can be reduced.

ii) As mentioned above, since the existing numeric keys are also used for input, there is no need to newly provide numeric keys for code input.

1ii) Since a diode switch is used as the PIN code setting means, the PIN code will not be lost when the power is turned off. Furthermore, it is much cheaper than conventional memory holding batteries and non-volatile memories, which are means for holding codes when the power is turned off.

■) Displaying the fact that the device has an anti-theft function reduces the desire to steal and is highly likely to prevent theft from occurring.

As explained in detail about the H1 invention, if the present invention is selected, even if a person makes a mistake in inputting a password, a person who knows the correct password can perform an operation to permit re-input. On the other hand, since a person who does not know the correct PIN code is unlikely to accidentally discover the re-entering operation, the correct PIN code itself can be protected, improving the anti-theft effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the anti-theft device for vehicle-mounted audio equipment according to the present invention, and FIG. 2 is a flowchart for explaining the operation of the anti-theft device for vehicle-mounted audio equipment according to the present invention. 1......Control block, 2......
...Operation key matrix, 3...Diode switch, 4...Battery, 5...
・・・・・・Display unit, 6・・・・・・Cassette block, 7・・・・・・Tuner block, 8
......Audio signal switch, 9...
...LED.

Claims (1)

[Claims] An anti-theft code input means, an anti-theft code setting means, and a backup power source that detects that the backup power source is turned off and requests code input only when the power source is closed after the detection. a detecting means; an operation inhibiting means for prohibiting the normal operation of the audio equipment when the code input is requested; the input code is compared with the code set by the code setting means, and the above is executed only when the two match. Comparison control means for canceling the operation prohibited state, and prohibiting the re-input of the code when the input code and the setting code do not match as a result of the above comparison, which is different from the normal operation of the predetermined operation means. A theft prevention device for an in-vehicle audio device, comprising: code input prohibition means that detects a predetermined operation and allows code input again.