JPH1027287A - Security device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify circuit constitution and to lower a cost by providing a means for turning an audio equipment to an unusable state when the audio equipment is disconnected from a power source and then connected again and turning the audio equipment in the unusable state to a usable state. SOLUTION: In a state where a CD 19 is loaded inside a CD player 11, in the case that the backup power source of the CD 10 with a radio is tentatively detached from a battery B and connected to the battery B again, a security operation is made to act. To put it concretely, a microcomputer 15 detects the change of the connection state of the backup power source from the storage state of a RAM 17 and executes the security operation at the time of detecting the storage loss state of the RAM 17. When the security operation is executed, the CD 10 with the radio becomes unoperatable. In order to cancel the unoperatable state, by a prescribed cancelling operation set beforehand, the unoperatable state is cancelled and the operation of the CD 10 with the radio is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to audio equipment,
In particular, the present invention relates to a security device for preventing the in-vehicle audio device from being stolen.

[0002]

2. Description of the Related Art Audio equipment, especially audio equipment mounted on vehicles for export, is susceptible to theft. For this reason, a security function using a security code (personal identification number) is often employed to prevent theft of the equipment. In this security function, a user of an audio device manually inputs an arbitrary security code from numeric keys or the like of the device, and the device side transmits the security code to an EEPROM (Electrically Erasabl).
e Programmable Read Only Memory). Then, the backup power supply terminal of the device (a terminal directly connected to the battery, which supplies power to a predetermined necessary part of the device (such as a memory or a microcomputer) without using an accessory switch switched by an ignition key) is once disconnected from the battery. In this case, the device is activated and cannot be used unless the password input when the battery is reconnected matches the password stored in the memory.

That is, when an audio device is stolen from a vehicle, the device is first detached from the vehicle and then attached to another vehicle again. This means that the device's backup power terminal and battery are disconnected and reconnected. A change in the connection state between the backup power supply terminal and the battery is detected by a change in the power supply, and when this state is detected, the above-described security function is executed,
The device will not start unless the correct PIN is entered. Therefore, even if the user removes the device from the car, the device cannot be started unless the user of the device knows the correct password. Then, the fact that the device has such a function is displayed on an automobile or a device. In other words, an indication such as "there is a security function and it is useless to carry away" is displayed on the vehicle or the device, thereby reducing the willingness of the person attempting to steal theft and attempting to prevent theft.

[0004]

However, in the conventional security device, the user uses a dedicated EEPROM to store the personal identification number in the memory, and determines whether or not to activate the security function. It was determined by whether or not it was recorded. For this reason, an EEPROM is required, which causes a cost increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a security device which is inexpensive and does not unnecessarily disable the equipment.

[0006]

SUMMARY OF THE INVENTION The present invention solves such a problem. In a security device for preventing theft of an audio device having a reproducing function of reproducing a storage medium, the storage medium is provided with the audio device. Detecting means for detecting that the storage medium is loaded, and detecting means for detecting that the storage medium is loaded when the audio device is connected again after being disconnected from a power source. It is characterized by comprising security operation means for disabling the device, and security releasing means for enabling the audio device disabled by the security operation means.

Further, the security operation means makes the audio device unusable when the power-off time is a predetermined time or more. The state of the power-off time is determined based on the storage content of a memory in which the storage content is held by an auxiliary battery provided in the audio device.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a compact disc player with a radio receiver for car (CD with radio) will be described as an example, but other cassette tapes, MD (mini disc), DAT (digital audio tape), DCC
The present invention can be applied to an audio device having a reproducing function of reproducing a storage medium such as a (digital compact cassette). Also, in an audio device equipped with a microprocessor (microcomputer), it can be easily applied without adding much hardware configuration.

FIG. 1 shows an audio apparatus (compact disc player with radio receiver) showing an embodiment of the present invention.
FIG. The CD with radio 10 is a CD (compact disk) player 11, a radio receiver 12, an amplifier 13, a speaker 14, a microprocessor (microcomputer).
15, a ROM 16, a RAM 17, a switch group 18, and the like. The CD player 11 reads information on a compact disk (CD) 19 as a storage medium, reproduces an audio signal, and reads lead-in information. Also, the CD player 11 includes the CD 19.
A sensor 20 is provided as detection means for detecting that the device is loaded inside the device by an optical sensor or the like. The radio receiver 12 receives a radio broadcast. The amplifier 13 amplifies audio signals from the CD player 11 and the radio receiver 12 and outputs the amplified signals from the speaker 14. The microcomputer 15 controls the CD player 11, the radio receiver 12, and the amplifier 13 and controls security-related operations.

The ROM 16 stores a program for processing performed by the microcomputer 15, a personal identification number for releasing a security state, and the like. The RAM 17 is used for arithmetic processing and the like, but the stored contents are lost when the power supply is completely cut off. Therefore, by monitoring the stored contents of the RAM 17, the removal from the power supply (battery) can be detected. Accessory power is supplied from a battery B to each component of the radio-equipped CD 10 via an ignition switch IGSW. An operation power supply terminal 21 of the microcomputer 15 has an ignition switch IGSW
The battery B is connected via a power supply terminal 22 and an ignition switch IGS
It is directly connected to the battery B without going through W.

The switch group 18 is composed of control switches such as preset switches and seek switches for music selection and channel selection for operating the CD player 11 and the radio receiver 12, and is usually provided on the front of the equipment and has a password. It is also used for entering numbers. CD with radio
An auxiliary power supply 23 is formed and built in the discharge power supply 10 using a discharge current of a capacitor. The auxiliary power supply 23 is formed so that the storage contents of the RAM 17 are retained for a predetermined time even when the backup power supply is disconnected from the battery B.

Next, a security operation in an audio device according to an embodiment of the present invention will be described. When the audio device is disconnected from the vehicle in the security mode (with the CD 19 loaded), and then re-attached to another vehicle, the security operation operates. That is, C
When the backup power supply of the radio-equipped CD 10 is once removed from the battery B and connected to the battery B again in a state where the CD 19 is loaded in the D player 11, the security operation is performed. Specifically, the microcomputer 15 detects the connection state of the backup power supply, that is, a change in the connection state of the backup power supply from the storage state of the RAM 17, and executes the security operation when the storage loss state of the RAM 17 is detected. For example, the microcomputer 15 writes a predetermined value to a specific address of the RAM 17 while the power is on, and checks the specific address of the RAM 17 when the power is turned on, and if the stored value of the specific address is a predetermined value. It is determined that the power supply has not been removed. When this security operation is performed, the radio CD 10 becomes inoperable. That is, the microcomputer 15 does not accept various switch operations except for a special operation set in advance.

In order to release the inoperable state, the inoperable state is released by a predetermined release operation set in advance, and the operation of the CD 10 with radio can be performed. Specifically, the backup power supply of the radio-equipped CD 10 is once removed from the battery B, and the security mode is set (the CD player 11).
In the case where the CD 19 is loaded in the CD), even if the ignition switch IGSW is turned on and the start-up operation (start-up switch ON) is performed, the radio-equipped CD 10 cannot be operated.
A display to the effect that the operation is impossible due to the security function operation is displayed on a display unit (not shown). Then, a display prompting the input of a predetermined release operation set in advance is performed, and when the predetermined release operation is performed, the security function is released, that is, a display indicating that the radio-equipped CD 10 is in an operable state is performed. After that, the normal operation (operation of the CD with radio 10) is performed.

[0014] The predetermined canceling operation set in advance is a simple password (sign) input operation.
For example, operation of the operation buttons of the CD player 11 and the radio receiver 12 such as double-pressing of the seek-up switch button and the third button of the preset switch, or triple-pressing of the seek-down switch button and the first and second buttons of the preset switch. It can be realized by a combination of order and time.

Next, the processing performed by the microcomputer 15 to realize these operations will be described. FIG. 2 is a flowchart illustrating a processing operation performed by the microcomputer. The radio-equipped CD10 is mounted on a car or the like, and the accessory switch of the car or the like is turned on (ignition switch IGSW
This process is started when the
Move to step S1. In step S1, the CD with radio
It is determined whether or not a power switch (not shown) is turned on. If the power switch is turned on, the process proceeds to step S2. If the power switch is not turned on, the state of the power switch is turned on until the power switch is turned on. Monitor. In step S2, it is determined whether or not the battery B has been removed. If the battery B has been removed, the process proceeds to step S3, and if not, the process proceeds to step S4.

This determination can be made by monitoring the value of a specific address of the RAM 17 in which a predetermined value is stored unless the power is turned off. In a normal maintenance operation, battery replacement, fuse replacement, and the like, the power supply is shut off for a short time, and the storage contents of the RAM 17 are retained by the auxiliary power supply 23. Therefore, it is not determined that the battery B has been removed due to theft or the like. .

In step S3, it is determined whether or not a CD 19 exists in the CD player 11. If a CD 19 exists, the process proceeds to step S5, and if not, the process proceeds to step S4. In step S4, the radio-attached CD 10 is set to the normal operation, and the process ends. In step S5, the security function is turned on, that is, the operation of the radio-equipped CD 10 is disabled, and the process proceeds to step S6. That is, step S
The CD is stored in the CD player 11 by the processing of 2, S3 and S5.
When the backup power supply is turned off once, the security function works and the CD with radio
Operation of 10 becomes impossible. In addition, normal maintenance,
For example, for 5 to 10 minutes such as when replacing the battery,
3, the content stored in the RAM 17 is retained, and the security function does not operate.

In step S6, it is determined whether or not an operation for releasing the security function has been performed. If the operation has been performed, the process proceeds to step S7. If not, the process returns to step S5 to continue the security function. The release operation of the security function is constituted by, for example, a combination of a switch operation sequence and a time such as a continuous push of the seek-up switch button and the third button of the preset switch for 10 seconds. Then, in step S7, the security mode is released and the mode is returned to the normal mode (the radio-equipped CD 10 can be operated), and this processing ends.

As described in detail above, in the present embodiment, the CD player 11 is removed from the car and stealed again after a lapse of a predetermined period of time, assuming that the CD 19 is loaded in the CD player 11. When installed on another car, security works and CD with radio
10 becomes inoperable. Then, by inputting a simple password, the security operation is released, and the operation of the radio-equipped CD 10 becomes possible. When the vehicle owner does not want to activate the security function, the security function can be prohibited by a simple operation of loading the CD 19.
In addition, the security mode is not set in normal maintenance such as battery replacement, and unnecessary security functions do not operate, and there is no need to perform unnecessary release operations or the like.

[0020]

As described in detail above, according to the present invention, the E for storing the security code without impairing the function of selecting whether to activate the security function.
Since the EPROM can be omitted, the circuit configuration can be simplified and the cost can be reduced.

In addition, since the security mode is not set when the power is turned off for a short time, such as when the battery is replaced, the security operation is not unnecessarily activated during normal maintenance work, and the troublesome release operation of security is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an audio device showing one embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing operation of a microcomputer.

[Explanation of symbols]

10 ··· Compact disc player with radio receiver (CD with radio) 11 ··· Compact disc player (CD player) 12 ··· Radio receiver 13 ··· Amplifier 14 ··· Speaker 15 ··· Microprocessor (microcomputer) 16 ··· ROM 17 ··· RAM 18 ··· Switch group 19 ··· Compact disk (CD) 20 ··· Sensor 21 ··· B Power supply terminal 22 Backup power supply terminal 23 Auxiliary power supply

Claims (3)

[Claims] 1. A security device for preventing theft of an audio device having a reproduction function of reproducing a storage medium, wherein: a detection unit for detecting that the storage medium is loaded in the audio device; and the audio device. Security operating means for disabling the audio device when the detection means detects that the storage medium has been loaded, when the power supply is disconnected and then reconnected, and A security device, comprising: a security canceling unit for setting an unusable audio device to an usable state. 2. The security device according to claim 1, wherein the security operation unit disables the audio device when a power-off time is equal to or longer than a predetermined time. 3. The security device according to claim 2, wherein the state of the power-off time is determined based on the storage content of a memory in which the storage content is held by an auxiliary battery provided in the audio device. .