JPH1040563A - Optical disc apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect an optical disc apparatus from damage and improve safe operation thereof by a method wherein a fuse surely blows for an over-current during normal-operation but does not blow for a surge current. SOLUTION: The optical disc apparatus comprises a power supply connecting means having the function to record, reproduce, erase and initialize the data on an optical disc using the light beam emitted from a semiconductor laser provided as a light source in order to realize connection with a power source supplied from external side. In this case, a current breaking means 3 is also provided for cutting off the supply of current to the optical disc apparatus 1 when a current flowing in the optical disc apparatus has an irregular value and a filter circuit 4 for eliminating noise of current supplied from the external circuit is inserted between the power supply connecting means and the current breaking means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device such as a CD-R drive and a CD-E drive,
The present invention relates to a file drive device such as a CD-ROM drive and an MO disk drive. In particular, when an overcurrent occurs in a circuit system inside the optical disk device, a connection between a power supply unit supplied from the outside and an internal portion of the optical disk device. The present invention relates to a protection function in which the current can be reliably shut off with the circuit system described above and the optical disk device is prevented from being damaged or the like, thereby improving safety.

[0002]

2. Description of the Related Art Normally, in an electronic device, a fuse or the like is provided between an external power supply unit and a device main body as a current cutoff means so as not to damage the device due to an overcurrent caused by an accident. Has been inserted. For example, a fuse functions to prevent the optical disk device from being damaged by an overcurrent caused by an accident and to enhance safety by preventing smoke or fire from occurring in advance. . Specifically, there is known a means for detecting a blown fuse caused by an overcurrent in the facsimile apparatus (for example, Japanese Utility Model Application Laid-Open No. 2-1456).
No. 7). In general, after the fuse,
In order to remove noise and the like superimposed on the power supply, a filter including an inductance and a capacitor is provided.

FIG. 5 shows a conventional optical disk device.
FIG. 3 is a functional block diagram illustrating an example of a configuration of a main part in a connection portion with the external power supply unit. In the figure, 1 is an optical disk device, 2 is a power connector, 3 is a fuse, 4 is a filter, 5 is an external power supply unit, L is an inductance, C is a capacitor, and VCC and GND are connection lines between the external power supply unit 5 and VCC. Show.

[0004] As shown in FIG.
A power supply connector 2 is provided at the power supply connection portion, and a current is supplied from the external power supply unit 5 through the connection lines VCC and GND. Inside the optical disc device 1, a security fuse 3 blown by an overcurrent and an inductance L
And a capacitor C, to which a filter 4 for removing current noise is connected. In this case,
A surge current is generated to charge the capacitor C of the filter 4. This surge current changes depending on the output impedance of the external power supply unit 5 actually connected and the rise time thereof.

FIG. 6 is a functional block diagram showing a state in which an external power supply unit is connected to the optical disk device. In the figure, 6 is an optical disk device, 7 is a first power supply unit, and 8 is a second power supply unit.

[0006] As shown in FIG.
In contrast, there are a case where a current is supplied from the first power supply unit 7 and a case where a current is supplied from the second power supply unit 8. In this case, the first and second power supply units 7, 8
Output impedance and rise time are different,
The amount of current output after the power is turned on also differs. This state will be described with reference to FIG.

FIG. 7 is a time chart for explaining the state of the current supplied from the two power supply units shown in FIG. 6 to the optical disk device. In the figure, the horizontal axis represents time, the vertical axis represents the power supply voltage and the current value output from the power supply, and the solid line A shows the characteristics of the power supply unit 7 and the broken line B shows the characteristics of the power supply unit 8.

The power supply voltage supplied from one power supply unit 7 rises sharply after the power is turned on, as indicated by the solid line A in FIG. 7, and the power supply voltage supplied from the other power supply unit 8 is B As shown by the broken line, it is assumed that it has a characteristic of rising more gradually than the solid line A. In this case, the current value supplied from each power source changes as shown by the solid line A below and the broken line B below. In other words, the current output from the power supply unit 7 which rises rapidly after the power is turned on, as indicated by the solid line A,
It increases and then decreases to an almost constant value. On the other hand, the current output from the power supply unit 8 that gradually rises, as indicated by the broken line B,
It increases slowly and its maximum value is smaller than the solid line A.

[0009] The current output from the power supply unit of either characteristic becomes a constant value consumed by the circuit system inside the optical disk device. As described above, the output current varies depending on the output impedance and the rise time of the power supply unit. Therefore, for example, in one power supply unit A, the fuse 3 is not blown by the surge current, but in the other power supply unit B, the fuse 3 is blown by the surge current. In addition, various experiments and the like have been performed on the amount of current at which the fuse blows. However, even if the amount of current flowing through the fuse is the same, the fuse is not blown or not depending on the time of current flow. Is known.

[0010]

As described in the prior art, due to the difference in output impedance and rise time of a power supply unit, in a certain power supply unit, a fuse does not blow due to a surge current. ,
In the case of another power supply unit, there is a problem that the fuse is blown by the surge current. In other words, if the fuse inserted to protect the optical disk device against an overcurrent caused by an accident during normal operation and to enhance safety is blown by the surge current at power-on, the optical disk device itself However, there is an inconvenience that the optical disk device does not function at all even if there is no abnormality in the power supply. According to the present invention, such inconveniences are solved, and the fuse is reliably blown against an overcurrent during normal operation, and the fuse is not blown against a surge current, so that the optical disk device is not damaged. And to improve safety.

[0011]

According to the first aspect of the present invention, there is provided a function for recording, reproducing, erasing, initializing, etc., data on an optical disk by light emitted from a semiconductor laser as a light source. In an optical disk device having a power supply connection unit connected to a supplied power, a current interrupting unit for interrupting current supply to the optical disk device when a current flowing through the optical disk device has an abnormal value; A filter circuit for removing noise of a current supplied from the outside is inserted between them.

According to a second aspect of the present invention, in the optical disk apparatus similar to the first aspect, when the current flowing through the optical disk apparatus has an abnormal value, the current interrupting means interrupts the current supply to the optical disk apparatus and the current interrupting means. A current path, a current path not passing through the current interrupting means, a current path switching means for switching between a current path passing through the current interrupting means and a current path not passing through the current interrupting means, and monitoring a voltage supplied to the optical disk apparatus. A voltage monitoring means is provided, and switching between a current path side not passing through the current interruption means and a current path side passing through the current interruption means is controlled by a detection output of the voltage monitoring means.

According to a third aspect of the present invention, in the optical disk device similar to the first aspect, when an electric current flowing through the optical disk device has an abnormal value, current interrupting means for interrupting current supply to the optical disk device, and a diode are provided. At least one or more diodes are connected in parallel with the current cutoff means, with the power supply connection side as a cathode.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment This first embodiment corresponds to the first aspect of the present invention. In the first embodiment, in order to absorb a surge current generated when the power is turned on, a filter circuit is arranged on the input side of the power supply unit, and a security fuse which is blown by an overcurrent is connected to a subsequent stage. It has features.

FIG. 1 is a functional block diagram showing an example of a first embodiment of a main part configuration of a connection portion to an external power supply unit in the optical disk device of the present invention. Reference numerals in the figure are the same as those in FIG.

FIG. 1 shows only a main part of a connection portion with an external power supply unit shown in FIG. 5 as a conventional example. The difference between the two is that the order of arrangement of the fuse 3 and the filter 4 connected to the connection line VCC side of the power supply connector 2 is different. That is, in FIG. 5 described above, a security fuse 3 blown by an overcurrent, an inductance L and a capacitor C are provided on the connection line VCC side of the power supply connector 2 that receives the current supplied from the external power supply unit 5. Then, a filter 4 for removing current noise is connected. On the other hand, in FIG. 1, a filter 4 also composed of an inductance L and a capacitor C is connected, and a security fuse 3 blown by an overcurrent is connected in series at a subsequent stage. Therefore, a current is supplied to the circuit system of the optical disk device via the fuse 3. With this connection, the surge current generated when the power is turned on is absorbed by the filter 4 at the preceding stage, so that an overcurrent that cuts the fuse 3 does not flow.

As described above, in the first embodiment, the fuse 3 and the filter 4 similar to the conventional one are used,
By merely changing the connection (arrangement) order, the fuse is reliably blown against an overcurrent during normal operation, and the fuse is not blown against a surge current.
That is, by changing the connection order of the filter 4 and the fuse 3, the surge current generated when the power is turned on is absorbed by the filter circuit (the filter 4), so that the fuse (3) is blown by the surge current. There is no. On the other hand, when an overcurrent flows due to an accident during normal operation, the fuse is blown. Therefore, it is possible to prevent the optical disk device from being damaged, and in the normal operation, the overcurrent is cut off by cutting the fuse, so that an optical disk device with high safety can be obtained.

Second Embodiment This second embodiment corresponds to the second aspect of the present invention. In the second embodiment, the fuse is reliably blown against an overcurrent during a normal operation and is not blown against a surge current when the power is turned on. The feature is that a current path is separately provided.

FIG. 2 is a functional block diagram showing an example of the second embodiment of the optical disk device according to the present invention in a main configuration of a connection portion with an external power supply unit. The reference numerals in the figure are the same as those in FIG. 5, 11 is a switch circuit, 12 is a CPU, 13 is a voltage monitoring circuit, and 14 is an added current path.

In the optical disk device shown in FIG. 2, the fuse 3 connected to the power supply connector 2 on the side of the connection line VCC is connected.
The arrangement order of the filter 4 and the filter 4 is the same as that shown in FIG. The difference is that a switch circuit 11 is provided between the connection line VCC of the power supply connector 2 and the fuse 3 to form another circuit (current path 14) in parallel with the fuse 3 so that a certain threshold level can be obtained when the power is turned on. When a voltage exceeding the threshold voltage is generated, the current path 14 is switched to the newly added current path 14 so that a surge current does not flow through the fuse 3. Specifically, the voltage on the output side of the filter 4 is monitored by the voltage monitoring circuit 13, and when a voltage equal to or higher than a preset threshold level is detected, the CPU 12 is notified to that effect. CP
U12 recognizes that the power has been turned on by this notification, and outputs a switch control signal to the switch circuit 11 to switch the switch circuit 11 connected to the fuse 3 to the current path 14 side. In this case, since the capacitor (C in FIG. 5) of the filter 4 has already been charged, no surge current occurs.

With this configuration, even if a surge current occurs when the power is turned on, the surge current passes through another path (current path 14) that does not pass through a fuse, and is thereafter absorbed by the filter circuit. After that, since the path is switched to the path via the fuse, there is no problem that the fuse is blown by the surge current when the power is turned on.
On the other hand, when an overcurrent flows due to an accident during normal operation, the fuse is blown, so that there is no risk of damaging the optical disk device, and safety is improved.
As described above, in the second embodiment, when the power is turned on, another current path that does not pass through the fuse is formed. Therefore, the problem that the fuse is blown by the surge current when the power is turned on occurs. do not do.

Third Embodiment This third embodiment corresponds to the third aspect of the present invention. In the third embodiment, the surge current generated at the time of power-on is short-circuited by a diode connected in parallel with the fuse, thereby avoiding the disadvantage that the fuse is blown by the surge current at the time of power-on. It has features.

FIG. 3 is a functional block diagram showing an example of a third embodiment of the optical disk device of the present invention in a main configuration of a connection portion to an external power supply unit. The reference numerals in the figure are the same as those in FIG. 1, and 15 indicates a diode.

In the optical disk device shown in FIG. 3, a diode 15 is added in parallel with the fuse 3 of the optical disk device shown in FIG. Generally, the resistance of a fuse is on the order of several hundred milliohms, which is smaller than the resistance of a diode. Therefore, when the power is turned on, the current supplied via the power supply connector 2 initially flows through the fuse 3, but the voltage drop generated in the fuse 3 due to the increase in the amount of surge current is connected in parallel. When the forward voltage of the diode 15 is exceeded, the surge current flows on the diode 15 side. This surge current is filtered by the filter 4 at the subsequent stage and supplied to the circuit system of the optical disk device.

When the surge current disappears with the lapse of time, the voltage drop generated in the fuse 3 also decreases. When the voltage drops below the forward voltage of the diode 15, the diode 15 is turned off. As a result, during normal operation,
The diode 15 is off, and a current flows to the filter 4 via the fuse 3.

FIG. 4 is a time chart for explaining the operation of the optical disk apparatus shown in FIG. 3 from the time when the power is turned on until the fuse is blown due to an accident. In the figure, the horizontal axis is time, the vertical axis is current, A is a current supplied from VCC, B is a current flowing through the fuse 3, and C is a diode 15
Shows the current that flows through.

As shown by the waveform A in FIG. 4, when a surge current is generated by turning on the power, a large current flows through the fuse 3 as shown by the waveform B. When the voltage due to the voltage drop exceeds the forward voltage of the diode 15, a current flows through the diode 15 as shown by the waveform C. Thereafter, when the surge current disappears, the voltage drop due to the fuse 3 also decreases, and the diode 1
When the forward voltage falls below 5, the diode 15 is turned off. In this state, as shown by the waveform B, a current flows only through the fuse 3 and a normal drive current is supplied to the circuit system of the optical disk device via the filter 4 at the subsequent stage. In this state, if an overcurrent flows through the optical disk device for some reason, a large current flows through the fuse 3 for a long time. When an overcurrent flows for a certain time or more, the fuse 3 is blown and the current supplied from VCC is cut off as shown in A.

Here, assuming that the resistance value of the fuse 3 is R, the forward voltage of the diode 15 is Vf, and the amount of overcurrent generated by an accidental accident of the optical disk device is I, the relationship of Vf> R × I is established. Thus, if each constant is set, if an overcurrent occurs in the optical disk device due to an accident,
Since the fuse 3 is blown by the current, the optical disk device can be protected. As described above, in the third embodiment, when a surge current occurs when the power is turned on, a voltage drop occurs in the fuse in accordance with the amount of the current, but the voltage drops in the diode connected in parallel with the fuse. When the forward voltage is exceeded, the surge current passes through the diode side, so that the fuse is not blown by the surge current. Further, when an overcurrent flows due to an accident during normal operation, the fuse is naturally blown, so that there is no risk of damaging the optical disk device and safety is improved.

[0029]

According to the first aspect of the present invention, the optical disk apparatus has a function of recording, reproducing, erasing, initializing, etc., data on the optical disk by light emitted from a semiconductor laser as a light source, and is supplied from outside. In an optical disk device having a power supply connection portion for connecting to a power supply, when an electric current flowing through the optical disk device has an abnormal value, a current interrupting means for interrupting a current supply to the optical disk device, and In addition, a filter circuit for removing noise of a current supplied from the outside is inserted. The surge current generated when the power is turned on is absorbed by the filter circuit, so that the fuse is not blown by the surge current, and when an overcurrent flows due to an accident during normal operation. , The fuse is blown. As a result, there is no possibility that the optical disk device is damaged, and the safety is improved.

According to the optical disk device of the second aspect, the first aspect
When the current flowing through the optical disk device is an abnormal value, the current interrupting means interrupts the current supply to the optical disk device, the current path passes through the current interrupting means, and the current path does not pass through the current interrupting means. A current path switching means for switching between a current path passing through the current interrupting means and a current path not passing through the current interrupting means; and a voltage monitoring means for monitoring a voltage supplied to the optical disk device. The output controls the switching between the side of the current path that does not pass through the current interrupting means and the side of the current path that passes through the current interrupting means. Therefore, even if a surge current occurs when the power is turned on, the surge current passes through another path that does not pass through the fuse, and is thereafter absorbed by the filter circuit. Then, since the path is switched to the path via the fuse, the fuse is not blown by the surge current when the power is turned on. Therefore, the same effect as that of the optical disk device of the first aspect can be obtained.

According to the optical disk device of the third aspect, the first aspect
When the current flowing through the optical disk device is an abnormal value, a current interrupting means for interrupting the current supply to the optical disk device and a diode are provided, and the power supply connection side is connected to the cathode in parallel with the current interrupting device. At least one or more diodes are connected. Therefore, if a surge current occurs when the power is turned on, a voltage drop will occur in the fuse in accordance with the amount of current, but if the voltage exceeds the forward voltage of the diode connected in parallel with the fuse, the surge current will drop to the diode side. Therefore, the fuse is not blown by the surge current. When an overcurrent flows due to an accident during normal operation, the fuse is naturally blown. Therefore, the same effect as that of the optical disk device of the first aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an example of a first embodiment of a main part configuration of a connection portion to an external power supply unit in an optical disc device of the present invention.

FIG. 2 is a functional block diagram showing an example of a second embodiment of a main part configuration of a connection portion to an external power supply unit in the optical disc device of the present invention.

FIG. 3 is a functional block diagram showing an example of a third embodiment of a main part configuration of a connection portion with an external power supply unit in the optical disc device of the present invention.

FIG. 4 is a time chart for explaining an operation of the optical disk device shown in FIG. 3 from power-on to a blow of a fuse due to an accident.

FIG. 5 is a functional block diagram showing an example of a configuration of a main part of a connection portion of a conventional optical disk device with an external power supply unit.

FIG. 6 is a functional block diagram showing a state in which an external power supply unit is connected to the optical disc device.

FIG. 7 is a time chart for explaining a state of a current supplied from the two power supply units shown in FIG. 6 to the optical disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk apparatus 2 Power supply connector 3 Fuse 4 Filter 5 External power supply unit 11 Switch circuit 12 CPU 13 Voltage monitoring circuit 14 Added current path 15 Diode

Claims (3)

[Claims] 1. A power supply connecting section for recording, reproducing, erasing, initializing, etc. data on an optical disk by emitting light from a semiconductor laser as a light source, and connecting to a power supply supplied from outside. An optical disk device comprising: a current interrupting unit that interrupts a current supply to the optical disk device when a current flowing through the optical disk device has an abnormal value; and an externally supplied current between the power supply connection unit and the current interrupting unit. An optical disc device comprising a filter circuit for removing current noise. 2. A recording medium having a function of recording, reproducing, erasing, initializing, etc., data on an optical disk by emitting light from a semiconductor laser as a light source, and having a power supply connection supplied from outside. In the optical disk device, when a current flowing through the optical disk device is an abnormal value, a current interrupting unit that interrupts a current supply to the optical disk device; a current path passing through the current interrupting unit; and a current path not passing through the current interrupting unit. A current path switching means for switching between a current path passing through the current interrupting means and a current path not passing through the current interrupting means; and voltage monitoring means for monitoring a voltage supplied to the optical disk device. Controlling the switching between the current path side not passing through the current interruption means and the current path side passing through the current interruption means by the detection output of the monitoring means. Characteristic optical disk device. 3. An optical disk has a function of recording, reproducing, erasing, initializing, etc., data on an optical disk by light emitted from a semiconductor laser as a light source, and has a power supply unit supplied from outside. An optical disk device, comprising: a current interrupting unit that interrupts a current supply to the optical disk device when a current flowing through the optical disk device is an abnormal value; and a diode. The power supply connection unit is connected to a cathode in parallel with the current interrupting unit. An optical disk device, wherein at least one or more diodes are connected.