JP2012221454A - Power supply circuit and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply circuit capable of suppressing destruction of a regulator when there is bad connection of an FFC, without providing a dedicated terminal for detecting a short circuit between a terminal for power supply and a ground terminal, at a connector to which the FFC can be connected.SOLUTION: The power supply circuit includes: a regulator; a power supply part for switching whether or not to supply power to the regulator according to a level of a control signal; and a connector to which an FFC (flexible flat cable) can be connected. The power supply circuit also includes a switching part for switching between a connection state and a cut-off state of an output side of the regulator and a signal line of the control signal. The connector has a terminal for power supply connected to the output side of the regulator; and a ground terminal. When the terminal for the power supply is short-circuited to the ground terminal, the switching part switches the output side of the regulator and the signal line to the connection state.

Description

  The present invention relates to a power supply circuit having a connector to which an FFC (flexible flat cable) can be connected.

  Conventionally, a power supply circuit is provided on a board of an electronic device such as a main board of an optical disk device or a mother board of a personal computer, and power is supplied from the power supply circuit to the outside via an FFC (flexible flat cable).

  However, when the connector of the FFC is obliquely inserted into the connector provided on the board and the power supply terminal of the connector provided on the board is short-circuited with the adjacent ground terminal, the components provided in the power circuit Could be destroyed.

  Therefore, for example, Patent Document 1 discloses the following power supply circuit. This power supply circuit has a DC / DC converter and a connector to which the FFC is connected, and a power supply terminal for supplying an output voltage of the DC / DC converter is provided on the connector. Further, a detection connection terminal is provided in the connector separately from the power supply terminal, and when the FFC is obliquely inserted into the connector, the detection connection terminal is connected to the detection connection terminal by short-circuiting with the ground terminal. The Low signal is input to the shutdown pin that is set to stop the operation of the DC / DC converter. Thereby, destruction of the DC / DC converter due to the FFC being obliquely inserted into the connector can be suppressed.

Japanese Patent Laid-Open No. 2008-112642 (FIG. 5 etc.)

  However, the power circuit disclosed in Patent Document 1 has a problem in that a special terminal called a detection connection terminal needs to be provided on the connector in addition to the power supply terminal.

  In view of the above problems, the present invention provides a regulator for a case where there is a defective connection of the FFC without providing a dedicated terminal for detecting a short circuit between the power supply terminal and the ground terminal in the connector to which the FFC can be connected. It is an object of the present invention to provide a power supply circuit capable of suppressing destruction and an optical disc apparatus including the same.

To achieve the above object, the present invention provides a regulator, a power supply unit that switches whether to supply power to the regulator according to the level of a control signal, a connector that can connect an FFC (flexible flat cable), A power supply circuit comprising:
A switching unit that switches between a connection state and a cutoff state between the output side of the regulator and the signal line of the control signal,
The connector has a power supply terminal connected to the output side of the regulator, and a ground terminal,
When the power supply terminal is short-circuited with the ground terminal, the switching unit is configured to switch the output side of the regulator and the signal line to a connected state.

  According to such a configuration, for example, even when the FFC is obliquely inserted into the connector and the power supply terminal is short-circuited to the ground terminal, the switching unit connects the output side of the regulator and the signal line of the control signal. Since the switching is performed, the power supply unit does not supply power to the regulator by the control signal. Therefore, without providing a dedicated terminal for detecting a short circuit between the power supply terminal and the ground terminal in the connector to which the FFC can be connected, it is possible to suppress the destruction of the regulator when the FFC is defectively connected.

  In the above configuration, the power supplied from the power supply terminal may be a power supply for components of the optical disc apparatus.

In any one of the above configurations, the power supply unit supplies power to the regulator when the control signal is at a high level, and does not supply power when the control signal is at a low level.
The switching unit may be a diode whose cathode is connected to the output side of the regulator and whose anode is connected to the signal line.

  According to such a configuration, when the power supply terminal is short-circuited with the ground terminal when the control signal is at the high level, the diode is turned on and the control signal is at the low level. Therefore, the power supply unit supplies power to the regulator. Stop supplying. Therefore, the operation of the regulator can be stopped instantaneously, and the destruction of the regulator can be further suppressed.

In the above configuration, the detection signal output from the anode is input to the microcomputer,
When the microcomputer detects that the detection signal is equal to or lower than a predetermined voltage, the microcomputer outputs the control signal at a low level and stops the power supply operation of at least one power supply circuit other than the power supply circuit. A configuration may be adopted in which a control signal is output to two power supply circuits.

  According to such a configuration, when the power supply terminal is short-circuited with the ground terminal when the control signal is at a high level, the diode is turned on, and the detection signal becomes a predetermined voltage or less. The microcomputer outputs a low level control signal and outputs a control signal to the at least one power supply circuit to stop the power supply operation of at least one power supply circuit other than the power supply circuit. As a result, the power supply operation of the power supply circuit is stopped and the power supply operation of at least one power supply circuit other than the power supply circuit is stopped. Therefore, for example, an operator who connects the FFC can notice a work failure.

  Further, the optical disc apparatus of the present invention is configured to include the power supply circuit having any one of the above configurations.

  According to the present invention, without providing a dedicated terminal for detecting a short circuit between the power supply terminal and the ground terminal in the connector to which the FFC can be connected, it is possible to suppress the destruction of the regulator when the FFC is defectively connected.

It is a schematic perspective view which shows the structure inside the chassis of the Blu-ray Disc apparatus which concerns on one Embodiment of this invention. It is a figure which shows schematic structure in the main board | substrate which concerns on one Embodiment of this invention. It is a figure which shows the circuit structure of the power supply circuit which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, an optical disk device, particularly a Blu-ray disc device will be described as an example.

  FIG. 1 is a schematic perspective view showing a configuration inside a chassis of a Blu-ray disc device according to an embodiment of the present invention. As shown in FIG. 1, a Blu-ray disc device according to an embodiment of the present invention includes a loader 1, a power supply board 2, and a main board 3 inside a chassis. A power supply board 2 and a main board 3 are arranged so as to sandwich the loader 1.

  The loader 1 is a device that mounts a Blu-ray disc inside and reads / writes data to / from the mounted Blu-ray disc. A tray for pulling in the Blu-ray disc from the outside, a tray motor for driving the tray, and a Blu-ray disc are fixed. Turntable, spindle motor that rotates the turntable, optical pickup that reads and writes data by irradiating the laser to the Blu-ray disc, and thread motor that drives the optical pickup in the radial direction of the Blu-ray disc (none of which are shown) Have.

  In addition, the optical pickup includes a laser diode capable of emitting a 405 nm band laser corresponding to a Blu-ray disc, an objective lens that focuses the laser on the recording surface of the Blu-ray disc, an actuator that drives the objective lens in the track direction and the focus direction, and a Blu-ray disc And a photodetector that performs photoelectric conversion by receiving the laser beam reflected by the laser beam, and other optical system components.

  The power supply board 2 is provided with an AC / DC power supply circuit (not shown) that converts an AC voltage 100V input from a power plug (not shown) into a DC voltage 11V. This AC / DC power supply circuit has a transformer and a rectifier circuit. The converted DC voltage 11V is sent to the main board 3 via a harness (not shown) passed through the lower part of the loader 1.

  As shown in FIG. 2, the main board 3 is provided with a microcomputer 50, a power supply circuit 100, and a plurality of power supply circuits 200 different from the power supply circuit 100. The power supply circuit 100 is a circuit that converts a DC voltage 11V sent from the power supply board 2 into a spindle motor power supply voltage 10V and a laser diode power supply voltage 8V, and a detailed configuration will be described later. The other power supply circuit 200 converts the DC voltage 11V sent from the power supply board 2 into a power supply voltage 5V, 3.3V, 1.5V, 1.1V, or the like. The microcomputer 50 controls each part of the device including the power supply circuit 100 and the power supply circuit 200.

  The main board 3 is provided with a connector 4 to which one end of the FFC 5 is connected. One end of the FFC 5 is connected to a control board (not shown) provided under the loader 1. Various power sources and various control signals can be sent to the loader 1 by the FFC 5.

  A detailed configuration of the power supply circuit 100 is shown in FIG. A power supply circuit 100 shown in FIG. 3 includes a MOSFET 10, a regulator 20, a transistor Tr, diodes Di1, Di2, resistors R1 to R9, capacitors C1, C2, and a connector 4.

  The MOSFET 10 is a package of a P-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), has a source terminal S, a gate terminal G, and drain terminals D1 to D4, and functions as a voltage follower.

  An input voltage Vin of DC 11V sent from the power supply substrate 2 is applied to one end of the resistor R1, and the source terminal S is connected to the other end. One end of the resistor R3 is connected to the gate terminal G, and a connection point between the resistor R1 and the source terminal S and a connection point between the gate terminal G and the resistor R3 are connected by the resistor R2.

  The transistor Tr is an NPN bipolar transistor. One end of a resistor R3 is connected to the collector of the transistor Tr, and the emitter of the transistor Tr is grounded. Further, a control signal S1 from the microcomputer 50 (FIG. 2) is input to the base of the transistor Tr via a line L1 (signal line).

  The drain terminals D1 to D4 of the MOSFET 10 are connected in common and connected to one end of the resistor R4. The resistor R4 and the resistor R5 are connected in series, and the power supply voltage Vo1 for the spindle motor is taken out from the connection point.

  The regulator 20 is a three-terminal regulator, and has an input terminal, an output terminal, and a voltage setting terminal. One end of the resistor R5, the cathode of the diode Di1 for preventing destruction of the regulator 20 and one end of the capacitor C1 for preventing oscillation are connected in common and connected to the input terminal of the regulator 20.

  The output terminal of the regulator 20, the anode of the diode Di1, one end of the resistor R6, one end of the oscillation preventing capacitor C2, and one end of the resistor R8 are connected in common and connected to one end of the resistor R9. The resistor R6 and the resistor R7 are connected in series, and the voltage setting terminal of the regulator 20 is connected to the connection point thereof. One end of the capacitor C1, one end of the resistor R7, and one end of the capacitor C2 are connected in common and grounded.

  The cathode of the diode Di2 is connected to one end of the resistor R8. One end of the line L2 and one end of the line L3 for outputting the detection signal S2 to the microcomputer 50 (FIG. 2) are connected in common and connected to the anode of the diode Di2. The other end of the line L2 is connected to the line L1.

  One end of the resistor R9 is connected to a power supply terminal T1 provided on the connector 4, and a power supply voltage Vo2 for a laser diode (component of the optical disk device) is output from the power supply terminal T1. A ground terminal T2 provided on the connector 4 adjacent to the power supply terminal T1 is grounded.

  When a high level control signal S1 is input from the microcomputer 50 to the base of the transistor Tr, the transistor Tr is turned on, and the gate voltage applied to the gate terminal G is at the low level, so that the MOSFET 10 is turned on and the drain terminal D1. DC voltage 10.5V is output from -D4. A power supply voltage Vo1 having a DC voltage of 10 V is taken out from the connection point between the resistors R4 and R5.

  Further, the regulator 20 converts an input voltage of about 10V applied to the input terminal into an output voltage of about 8V and outputs the output voltage from the output terminal. Then, a power supply voltage Vo2 that is a DC voltage of 8V is output from the power supply terminal T1. If the FFC 5 (FIG. 1) is normally connected to the connector 4 and the power supply terminal T1 is not short-circuited with the ground terminal T2, the diode Di2 is turned off.

  When the FFC 5 is obliquely inserted into the connector 4 and the power supply terminal T1 is short-circuited to the ground terminal T2, and the control signal S1 is at a high level, the power supply voltage Vo2 becomes low, so the diode Di2 is turned on. It becomes. Then, since the control signal S1 becomes a low level, the transistor Tr is turned off and the MOSFET 10 is turned off. As a result, the voltage output from the drain terminals D1 to D4 is stopped, the output of the power supply voltage Vo1 is stopped, and the regulator 20 stops its operation. Therefore, the operation of the regulator 20 can be stopped instantaneously to prevent the regulator 20 from being destroyed.

  Further, the microcomputer 50 monitors the detection signal S2 every several hundreds msec, and when detecting that the detection signal S2 is 2V (predetermined voltage) or less, the microcomputer 50 controls the control signal S1 and all the power supply circuits 200. The signal S3 (FIG. 2) is set to the Low level, and the power supply operation of the power supply circuit 100 and all the power supply circuits 200 is stopped. The power supply circuit 200 may be configured to switch whether to supply power in accordance with the control signal S3 using, for example, a transistor and a MOSFET, similarly to the power supply circuit 100.

  As described above, when the diode Di2 is turned on, the detection signal S2 becomes 2 V or less, so the microcomputer 50 detects this and stops the power supply operation of the power supply circuit 100 and all the power supply circuits 200.

  Here, the operation of the power supply circuit 100 in the assembly process of the Blu-ray disc device according to the embodiment of the present invention will be described.

  When the operator connects the FFC 5 to the connector 4 in the assembly process and then inserts a power plug (not shown) into the tap, the DC voltage 11V is supplied from the power board 2 to the main board 3 and the microcomputer 50 is activated. When activated, the microcomputer 50 outputs a high level control signal S1 to the base of the transistor Tr. If the FFC 5 is normally connected to the connector 4, the power supply voltage Vo1 and the power supply voltage Vo2 are normally output.

  However, when the FFC 5 is obliquely inserted with respect to the connector 4 and the power supply terminal T1 is short-circuited with the ground terminal T2, the diode Di2 is turned on, so that the control signal S1 becomes a low level and the operation of the regulator 20 The output of the power supply voltage Vo1 and the power supply voltage Vo2 is stopped. Further, since the diode Di2 is turned on, the detection signal S2 becomes 2V or less, and the microcomputer 50 detects this and stops the power supply operation of the power supply circuit 100 and all the power supply circuits 200. As a result, each part of the apparatus including the laser diode and the spindle motor becomes inoperable, so that the operator can notice the work failure.

  The worker who notices the work failure reconnects the FFC 5 to the connector 4 normally and inserts the power plug into the tap. Then, since the regulator 20 is not destroyed, the power supply voltage Vo2 is normally output together with the power supply voltage Vo1.

  Thus, according to the present invention, the connector 4 is not provided with a dedicated terminal for detecting a short circuit between the power supply terminal and the ground terminal, and even when the FFC 5 is obliquely inserted into the connector 4, the regulator is instantaneously provided. 20 operation can be stopped, and the destruction of the regulator 20 can be suppressed.

  Although one embodiment of the present invention has been described above, the embodiment can be variously modified within the scope of the gist of the present invention.

  For example, in the above embodiment, the Blu-ray disc device has been described as an example, but the present invention can naturally be applied to other optical disc devices such as a DVD device, and the present invention can be applied to a power supply circuit provided on a motherboard provided in a personal computer. It is also possible to do.

1 Loader 2 Power supply board 3 Main board 4 Connector 5 FFC
10 MOSFET (Power supply unit)
20 regulator 50 microcomputer 100 power supply circuit 200 power supply circuit Tr transistor S source terminal G gate terminal D1 to D4 drain terminal Di1 diode Di2 diode (switching unit)
R1-R9 Resistor C1, C2 Capacitor L1-L3 Line T1 Power supply terminal T2 Ground terminal Vin Input voltage Vo1, Vo2 Power supply voltage S1, S3 Control signal S2 Detection signal

Claims (5)

A power supply circuit comprising a regulator, a power supply unit that switches whether to supply power to the regulator according to the level of a control signal, and a connector that can be connected to an FFC (flexible flat cable),
A switching unit that switches between a connection state and a cutoff state between the output side of the regulator and the signal line of the control signal,
The connector has a power supply terminal connected to the output side of the regulator, and a ground terminal,
When the power supply terminal is short-circuited to the ground terminal, the switching unit switches the output side of the regulator and the signal line to a connected state.   The power supply circuit according to claim 1, wherein the power supplied from the power supply terminal is a power supply for components of an optical disc apparatus. The power supply unit supplies power to the regulator when the control signal is at a high level, and does not supply power when the control signal is at a low level.
The power supply circuit according to claim 1, wherein the switching unit is a diode having a cathode connected to an output side of the regulator and an anode connected to the signal line. The detection signal output from the anode is input to the microcomputer,
When the microcomputer detects that the detection signal is equal to or lower than a predetermined voltage, the microcomputer outputs the control signal at a low level and stops the power supply operation of at least one power supply circuit other than the power supply circuit. 4. The power supply circuit according to claim 3, wherein a control signal is output to one power supply circuit.   An optical disc apparatus comprising the power supply circuit according to claim 1.

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