JPH08167282A - Theft preventing device for optical disk player - Google Patents

Abstract

PURPOSE: To prevent a theft, etc., in nonuse by sensing vibration from the outside from a result that a current occurring in an actuator coil of an optical pickup is compared with a prescribed value after detected and amplified, and issuing alarm. CONSTITUTION: A switch circuit 11 provided between the actuator coil 9 of the optical pickup and the drive circuit 10 for the coil 9 is set in a theft prevention circuit 12 side in nonuse of a player. Then, an amplifier circuit 13 amplifies the current occurring in the coil 9, and a comparator circuit 14 compares the output of the circuit 13 with the prescribed value, and it outputs a detection signal when the prescribed value or above. A latch circuit 15 latches the detection signal from the circuit 14 to impart it to an external output circuit 16, and the circuit 16 operates an external equipment 17 to issue the alarm. Thus, the coil 9 senses the vibration from the outside and issues the alarm is nonuse of the player, and the theft, etc., is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antitheft device for an optical disc player having an optical pickup.

[0002]

2. Description of the Related Art Conventionally, an optical disk player having an optical pickup has a structure in which an actuator section and a peripheral circuit in a pickup section are schematically shown in FIG. The actuator unit 1 includes an objective lens 3 for a laser diode that reads data on the optical disc 2.
Is composed of a focus actuator coil 4 that moves in the vertical direction Y to follow the data and a tracking actuator coil 5 that moves in the horizontal direction X. The peripheral circuit 6 includes the focus actuator coil 4
The focus actuator coil drive circuit 7 generates a coil current for driving the tracking actuator coil 5 and the tracking actuator coil drive circuit 8 generates a coil current for driving the tracking actuator coil 5.
The focus actuator coil drive circuit 7 is connected to the focus actuator coil 4,
The tracking actuator coil drive circuit 8 is connected to the tracking actuator coil 5.

[0003]

However, in such a conventional technique, the player has only the original function of the player, that is, the function of reproducing the data of the optical disc 2, No anti-theft measures were taken during use.

The present invention has been made by paying attention to such conventional technology and the present situation, and in order to prevent theft and the like when the optical disk player having an optical pickup is not used, vibration is prevented. It is an object of the present invention to provide an antitheft device that senses and issues an alarm.

[0005]

In order to achieve the above object, the present invention is directed to an anti-theft device for an optical disc player equipped with an optical pickup for reading information from an optical disc. The detection means for detecting by the current generated in the actuator coil of the optical pickup which behaves according to the above, the comparison means for comparing the output of the detection means with a predetermined value, and the alarm means for issuing an alarm by the output of the comparison means. It is characterized by that.

[0006]

That is, when vibration is externally applied to the player body when not in use, a current is generated in the actuator coil such as the focus actuator coil or the tracking actuator coil that behaves due to this vibration according to the framing law. By monitoring this current, the vibration applied from the outside is sensed, and if the level is above a predetermined value, it is judged as theft and an alarm is issued.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same reference numerals are used for the parts common to the conventional example and the embodiment, and the duplicated description will be omitted.

The antitheft device for an optical disk player of the present invention is constructed by directly using the actuator section 1 and the peripheral circuit 6 in the pickup section of the conventional optical disk player shown in FIG. Specifically, Fig. 2
As shown in the block diagram of FIG. 1, a switching circuit is provided between the actuator coil 9 such as the focus actuator coil 4 and the tracking actuator coil 5 and the actuator coil drive circuit 10 such as the focus actuator coil drive circuit 7 and the tracking actuator coil drive circuit 8. 11 is provided, and the antitheft circuit section 12 is provided so as to be selectively connectable to the actuator coil 9. The antitheft circuit section 12 is not activated during normal operation of the player and is activated only when not in use. It was done like this.

An anti-theft circuit section 1 is provided by the switching circuit 11.
When 2 is selected, when vibration is applied to the player body from the outside, a current is generated in the actuator coil 9 that behaves due to the vibration, and this current is amplified and detected by the amplification circuit 13 that is the detection means. To be done. The amplified current is then fed to the comparator circuit 1 which is a comparison means.
4 is compared with the predetermined value set in 4, and if it is equal to or larger than the predetermined value, a vibration detection signal is output. Note that this means the setting of the sensitivity, and it is also possible to set the gain in the amplifier circuit 13 described above. The vibration detection signal output from the comparator circuit 14 is latched by the next latch circuit 15 and continues to be output to the next external output circuit 16 until reset. Then, when the vibration detection signal is output to the external output circuit 16, the vibration detection signal is then output to the external device 17, which is the alarm means, and an alarm is issued. The external device 17 is provided with some kind of alarm device such as a crime prevention bell or buzzer in the player body, and can also be used as a vehicle horn or headlight. When used at home, various external devices such as a radio and a cassette player can be used. Things are available. The anti-theft circuit 12 and the external device 17 are provided with a backup battery so that they can operate even when the main power source is disconnected.

The anti-theft device for an optical disk player according to the present invention is configured as described above, so that the actuator section 1 and the peripheral circuit 6 in the pickup section of the conventional optical disk player can be used as they are, and the device can be protected from the outside in the case of theft. It is possible to detect an applied vibration and issue an alarm, so that theft or the like can be prevented.

Regarding the actual operation of the present invention, the operation is performed according to the flow shown in the flow chart of FIG. 2. First, in step S2, it is confirmed that the power source of the player is off, and then, The operation is started only when the Acc power supply is turned off in step S3. However, when the Acc power supply is turned off in step S3, the transition to the subsequent steps is delayed until a predetermined time elapses by the timer control in the next step S4. This is to prevent malfunctions due to vibrations such as door tightening of the vehicle when immediately moving to the next step and operating immediately after turning off the Acc power supply. Regarding the setting of this predetermined time, a predetermined value is stored in the memory of the microcomputer arbitrarily or appropriately, and is read out each time and controlled by a timer. It is also possible to turn on / off the operation of this device using a remote control (the use of the remote control makes it unnecessary to set a predetermined time).

Next, in step S6, it is confirmed whether or not the power source of the present device is turned on. If it is off, the process proceeds to the end of step S11, and if it is on, the process proceeds to the next step S7. . In this example,
The power supply for this device is a backup power supply. In step S7, it is monitored whether or not a vibration is applied from the outside, and if it is not applied, a jump is made before step S6 and a loop is formed in steps S6 and S7. When it is detected that vibration is applied, the process proceeds to the next step S8, and a vibration detection signal is output to the external output.

Then, in step S9, it is confirmed whether or not the reset is applied. If the reset is not applied, it is jumped before step S6, and it is monitored whether or not the external vibration is applied again. If reset is performed, the process proceeds to the next step S10 and Ac
c Check if the power is off, if it is off, jump to the step before step S6 to monitor if external vibration is applied again, and if it is on, move to the next step S11. And then it ends.

[0014]

The antitheft device for an optical disk player according to the present invention has the contents as described above, and the vibration applied from the outside by directly utilizing the actuator section and the peripheral circuit in the pickup section of the conventional optical disk player. It is possible to detect an alarm and issue an alarm to prevent theft and the like. In addition, when the device of the present invention is used in a vehicle, it is possible to prevent the vehicle itself from being stolen or the like by the above, and it is also used to detect an earthquake depending on the usage. It is possible.

[Brief description of drawings]

FIG. 1 is a block diagram of an anti-theft device for an optical disc player according to the present invention.

FIG. 2 is a flow chart of an anti-theft device for an optical disc player according to the present invention.

FIG. 3 is a schematic diagram showing an actuator unit and a peripheral circuit in a pickup unit of an optical disc player having a conventional optical pickup.

[Explanation of symbols]

 2 ... Optical disc 9 ... Actuator coil 13 ... Amplification circuit (detection means) 14 ... Comparator circuit (comparison means) 17 ... External device (alarm means)

Claims (1)

[Claims] 1. An anti-theft device for an optical disc player equipped with an optical pickup for reading information from an optical disc, wherein vibration externally applied to the player body is detected by a current generated in an actuator coil of the optical pickup which behaves due to the vibration. An anti-theft device for an optical disc player, comprising: detection means, comparison means for comparing the output of the detection means with a predetermined value, and alarm means for issuing an alarm according to the output of the comparison means.