JP4340220B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disc apparatus, and more particularly to a technique for ensuring the reliability and safety of use of an optical pickup.

  2. Description of the Related Art Conventionally, in an optical disc apparatus, as a technique for preventing erroneous emission of a laser diode, as shown in FIG. 4, two trays (not shown) for carrying in or out an optical disc (not shown) are connected in series. Are detected by the switches (detection switches) 16 and 17 ', and the recording signal generator 12 and the laser drive circuit 7 are controlled by the microcomputer 15 based on the detection results, and the outputs of the laser diodes are turned on / off. The power supply to 6 is turned on / off to cause the laser diode 6 to perform a light emission operation or to stop the light emission. That is, in the state where the tray is inserted in the apparatus main body, the two switches 16 and 17 ′ turn on the output from the recording signal generation unit 12 and the laser drive circuit 7 to supply power to the laser diode 6. The laser diode 6 is caused to emit light. On the other hand, when the tray is pulled out from the apparatus main body, the two switches 16 and 17 'turn off the output from the recording signal generator 12 and the laser drive circuit 7 to cut off the power supply to the laser diode 6. The laser diode 6 is prevented from emitting light.

  Further, as a technique related to the present invention and described in the patent document, for example, Japanese Patent Application Laid-Open No. 2004-280934 (Patent Document 1), Japanese Patent Application Laid-Open No. 5-135397 (Patent Document 2), There are some which are described in Japanese Unexamined Patent Publication No. 2002-74720 (Patent Document 3). Japanese Patent Application Laid-Open No. 2004-280934 discloses that when a tray (drawer) or a drawer portion is pulled out, the laser light source (equivalent to a laser diode) is prevented from being turned on without affecting the circuit elements in the apparatus. When the drawer unit is not stored in a predetermined position of the cabinet, a low level signal is output from the storage detection switch to the CPU, and based on this, the CPU sends a low level signal to the driving transistor. Based on this, a configuration is described in which the voltage supplied from the power source to the driver IC and the processing amplifier is cut off, and Japanese Patent Application Laid-Open No. 5-135397 discloses that an optical disc apparatus has a laser beam leaked during maintenance and human In order to prevent damage to the device under a simple, small, and low-cost device configuration, Only when the rotation speed is reached and a synchronization signal is generated, a laser emission command is issued to the laser drive circuit (laser drive circuit) so that laser light (laser light) is emitted. A configuration in which light is not emitted is described. Further, Japanese Patent Laid-Open No. 2002-74720 discloses that a part of a signal line formed on the rotation mechanism unit is cut off in order to reliably stop the function of the optical head when the tray is out. The signal line element corresponding to the cut portion is provided on the lower surface of the tray, and the signal on the rotation mechanism unit is only when the tray is at a predetermined position in the apparatus main body and the rotation mechanism unit is at a predetermined lifted position. A configuration is described in which a circuit is formed so that the signal line element on the lower surface of the tray is connected to the line cutting portion, and the optical head is driven.

JP 2004-280934 A Japanese Patent Laid-Open No. 5-135397 JP 2002-74720 A

  In any of the above prior arts, when static electricity is applied to the optical pickup, an overvoltage due to the static electricity is applied to the laser diode, so that the laser diode may be destroyed. Also, when a driving signal is output from the laser driving circuit, even if it is due to a malfunction, the driving signal is supplied to the laser diode, and the laser diode emits light (erroneous light emission). become. In particular, in the case of an optical disc apparatus configured such that the objective lens of the optical pickup is located outside the apparatus main body when the tray is pulled out from the apparatus main body, the objective lens is exposed at the position. Therefore, when the laser diode emits light in this state, the laser light is emitted from the exposed objective lens, and may enter the eyes of the user or the like to impair health.

In view of the above-described prior art, the problem of the present invention is that in the optical disk apparatus, even when static electricity is applied to the optical pickup, the laser diode is prevented from being destroyed and the tray is pulled out from the apparatus main body. In the state, even if a driving signal is output from the laser driving circuit, the laser diode does not emit light erroneously.
An object of the present invention is to solve such problems and to provide a technique capable of ensuring reliability and safety in an optical disc apparatus.

In order to solve the above problems, in the present invention, in the optical disc apparatus, a detection switch is connected in parallel to the laser diode, and the detection switch detects that the tray is in a position pulled out of the apparatus body. , when in said position, a structure for short-circuiting the laser diode detection switch becomes conductive.

  According to the present invention, even when static electricity is applied to the optical pickup in the optical disc apparatus, the laser diode can be protected from destruction due to the overvoltage of the static electricity. In addition, when the tray is pulled out from the main unit, the laser diode can be prevented from emitting light even if a drive signal is output from the laser drive circuit due to malfunction of the device. The safety of the device can be ensured.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1-3 is explanatory drawing of the Example of this invention. FIG. 1 is a structural example diagram of an optical disk device as an embodiment of the present invention, FIG. 2 is a perspective view of the optical disk device of FIG. 1, and FIG. 3 is a drive structural example diagram of a laser diode.

  In FIG. 1, 1 is an optical disk device, 2 is an optical disk, 3 is a spindle motor for rotationally driving the optical disk 2, 4 is irradiated with laser light on the optical disk 1, and information is recorded on the optical disk 2, An optical pickup that reads recorded information from the optical disk 2, 5 is an objective lens in the optical pickup 4, 6 is a laser diode that generates laser light, 7 is a laser drive circuit that drives the laser diode 6, 8 is a light receiving unit that receives laser light from the objective lens 5 and converts it into an electrical signal, 9 is an actuator that changes the position and orientation of the objective lens, and 10 is an optical pickup 4 in the radial direction of the optical disc 2 (disc radial direction). The movement / guide mechanism section 10a that is moved while being guided to the rear is guided as a drive source for the movement / guide mechanism section 10. A slide motor for rotating a screw (not shown), 11 a motor drive circuit for driving the spindle motor 3 and the slide motor 10a, 12 a recording signal forming unit for forming a recording signal, and 13 a light receiving unit 8 A reproduction / error signal processing unit 14 that forms a reproduction signal by demodulation processing or the like based on an output signal from the signal, or forms a corresponding signal by detecting a recording error or reproduction error, drives the actuator 9. A focus / tracking control unit for generating a focus control signal and a tracking control signal, 15 is a microcomputer as a control means for controlling the entire optical disk apparatus, and 16 is connected in series to the laser diode 6 to carry in the optical disk 2 or A tray (not shown) for carrying out is a predetermined position (first position) in the apparatus main body. For example, detection switches A and 17 as first detection switches for detecting that the spindle motor 3 is inserted at a rotatable position are connected in parallel to the laser diode 6 and the tray is in a position other than the first position. Position (second position) For example, the detection switches B and 30 serving as second detection switches that are detected to be in a position of being pulled out (discharged) from the inside of the apparatus main body, It is a turntable to be mounted for.

  In the above configuration, at the time of recording or reproduction, the optical disc 2 is carried (inserted) into the main body of the optical disc apparatus 1 by the tray, separated from the tray at the first position which is a predetermined position, and a turntable (not shown). It is mounted on the spindle motor 3 so that it can be rotated by the spindle motor 3, and the detection switch A16 is (or has reached) the tray at a predetermined position (first position) in the apparatus main body. Is detected. Based on the detection result, the microcomputer 15 forms and outputs a control signal for operating the laser driving circuit 7 and a control signal for operating the recording signal generating unit 12. At this time, the detection switch B17 is in a non-conductive state. The laser driving circuit 7 outputs a driving signal for driving the laser diode 6 and supplies the driving signal to the laser diode 6. At the time of recording, a driving signal corresponding to the recording signal from the recording signal generator 12 is formed and output. The laser diode 6 is driven by the driving signal and generates (emits) laser light having a predetermined intensity. The laser beam is applied to the recording surface of the optical disc 2 through the objective lens 5 to perform recording or reproducing operation.

  On the other hand, for example, when recording or reproduction is completed or when recording or reproduction is newly performed, the tray is at a position other than the first position, such as a position where the tray is pulled out (discharged) from the inside of the apparatus main body. When it is in the second position, the detection switch B17 detects that the tray is in the position and becomes conductive. Since the detection switch B17 is connected in parallel to the laser diode 6, the laser diode 6 is short-circuited by conduction. At this time, the detection switch A16 is in a non-conductive state, for example, and the microcomputer 15 does not form a control signal for operating the laser drive circuit 7 or a control signal for operating the recording signal generation unit 12. When the tray is at the position (second position), even if, for some reason, the microcomputer 15 or the laser drive circuit 7 malfunctions and a drive signal is output from the laser drive circuit 7, the drive signal is , Flows through the detection switch B17 in the conductive state, and is not supplied to the laser diode 6. For this reason, the laser diode 6 does not emit laser light. In addition, when the tray is in the position (second position), static electricity is applied to the optical pickup by a charged user's tentacle or the like, and an overvoltage due to the static electricity is generated at both ends of the laser diode 6. The overvoltage is reduced by the conductive detection switch B17. For this reason, the laser diode 6 is not destroyed by the overvoltage.

Hereinafter, the same reference numerals as those in FIG. 1 are used for the components of the apparatus configuration in FIG. 1 used in the description of FIGS.
FIG. 2 is a perspective view of the optical disc apparatus 1 of FIG. 1 and shows a state where the tray is being pulled out from the apparatus main body. In this optical disk apparatus, the optical pickup 4, the spindle motor 3, the movement / guide mechanism unit 10 and the like are moved and displaced together with the tray.

  In FIG. 2, 20 is a tray, 21 is a rail member engaged with the side edge of the tray 20, 41 is a top case that covers the optical disk mounting side of the apparatus, 42 is a bottom case that covers the apparatus together with the top case 41, 50 is a hole provided in the top case 41 side so that the front-end | tip part of the turntable 30 may not contact | abut. The other symbols in FIG. 2 indicate the same components as in FIG. In this configuration, it is assumed that the detection switch A16 (FIG. 1) and the detection switch B17 (FIG. 1) are mounted on the base side of a chassis or the like to which the top case 41 and the bottom case 42 are fixed. It shall be actuated by inserting / ejecting (drawing out) the main body. When the tray 20 is pulled out from the apparatus main body, the objective lens 5 (FIG. 1) in the optical pickup 4 is also exposed to the outside. In this state, when the laser diode 6 (FIG. 1) in the optical pickup 4 emits light, there is a possibility that the laser light by the light emission may enter the eyes of the user and harm the health of the user. As described with reference to FIG. 1, the conduction state of the detection switch B <b> 17 does not cause the laser diode 6 to emit light when the tray 20 is ejected (drawn), and there is no risk of harming the health of the user.

FIG. 3 is a drive configuration example diagram of the laser diode 6.
In FIG. 3, a detection switch A16 as a first detection switch detects that the tray 20 (FIG. 2) is inserted at a predetermined position (first position) in the apparatus main body. A detection switch B17 as a second detection switch is connected in parallel to the laser diode 6 and when the tray 20 is at a position (second position) other than the first position, such as a position pulled out from the apparatus main body. When the tray is in this position, it becomes conductive. The microcomputer 15 forms a control signal based on the detection result of the detection switch A16 or the detection result of the detection switch B17, and controls the operation of the recording signal generation unit 12 and the laser drive circuit 7. When the tray 20 is at a predetermined position (first position) in the apparatus main body, the detection switch B17 is turned off so that a driving signal from the laser driving circuit 7 is supplied to the laser diode 6. To do. On the other hand, when the tray 20 is in the position (second position) pulled out from the apparatus main body as shown in FIG. 2, the detection switch B17 is in a conductive state, and the detection switch A16 is in a non-conductive state, for example. Therefore, the microcomputer 15 prevents the control signal for operating the laser drive circuit 7 and the control signal for operating the recording signal generation unit 12 from being formed. When the detection switch B17 is turned on, the laser diode 6 is short-circuited by the detection switch B17. For this reason, for example, even when the microcomputer 15 or the laser drive circuit 7 malfunctions and a drive signal is output from the laser drive circuit 7, the drive signal is not supplied to the laser diode 6, and the laser diode 6 Even when, for example, static electricity is applied to the optical pickup 4 by the charged tentacles of the user and an overvoltage due to the static electricity is generated at both ends of the laser diode 6, the overvoltage is detected by the detection switch B17. As a result, the laser diode 6 is protected from destruction.

  The detection switch A16 detects the position of the tray 20 when the tray 20 (FIG. 2) is inserted into a predetermined position (first position) in the apparatus main body and becomes non-conductive. Alternatively, when the tray 20 is at the position (second position) pulled out from the inside of the apparatus main body, it may be in a conductive state. However, in the conductive state, the microcomputer 15 prevents the control signal for operating the laser drive circuit 7 and the control signal for operating the recording signal generation unit 12 from being formed.

According to the above embodiment, when the tray 20 is at the position (second position) pulled out from the inside of the apparatus main body, the laser diode 6 is short-circuited by the detection switch B17. Even when 7 malfunctions, the laser diode 6 can be prevented from emitting laser light, and can be prevented from being destroyed by overvoltage due to static electricity. As a result, it is possible to ensure safety and improve reliability in the optical disc apparatus.

  In the above-described embodiment, the detection switch A16 and the detection switch B17 are attached to the base portion side to which the top case 41 and the bottom case 42 are fixed. One or both of the switches 16 and 17 may be configured to be attached to a member that moves together with the tray 20. Further, each of the detection switch A16 and the detection switch B17 does not need to be one switch, and may be composed of a plurality of switches. Further, both the detection switches may be mechanical switches or electronic switches using transistors or the like.

1 is a configuration example diagram of an optical disc apparatus as an embodiment of the present invention. FIG. 2 is a perspective view of the optical disc apparatus of FIG. 1. FIG. 2 is a drive configuration example diagram of a laser diode in the optical disc apparatus of FIG. 1. It is a drive structural example figure of the laser diode in the conventional optical disk apparatus.

Explanation of symbols

1 ... Optical disk device,
2 ... Optical disc,
3 ... Spindle motor,
4 ... Optical pickup,
5 ... Objective lens,
6 ... Laser diode,
7 ... Laser drive circuit,
8: Light receiving part,
9 ... Actuator,
10: Movement / guide mechanism,
10a ... slide motor,
11 ... Motor drive circuit,
12: Recording signal forming section,
13: Reproduction / error signal processing unit,
14 Focus / tracking control unit,
15 ... Microcomputer,
16: Detection switch A,
17: Detection switch B,
30 ... Turntable,
20 ... Tray,
21 ... Rail member,
41 ... Top case,
42 ... Bottom case,
50 ... hole.

Claims (3)

An optical disc apparatus for recording or reproducing information on an optical disc using an optical pickup,
A laser diode that generates laser light in the optical pickup;
A laser driving circuit for driving the laser diode;
A first detection switch for detecting that a tray for loading or unloading the optical disc is inserted at a predetermined first position in the apparatus main body;
Is connected in parallel to the laser diode, the tray detects that the second position other than the first position, Ri Do a conduction state when it is detected that is in the second position, the tray A second detection switch that is in a non-conductive state when is in the first position ;
Control means for forming and outputting a control signal for operating the laser drive circuit based on at least a detection result by the first detection switch;
And when the tray is in the first position, a driving signal is supplied from the laser driving circuit to the laser diode by the non-conduction of the second detection switch so that the laser diode can emit light. When the tray is in the second position, the laser diode is short-circuited to be in a non-light emitting state by the conduction of the second detection switch. Optical disk device.   The optical disc apparatus according to claim 1, wherein the first and second detection switches and the laser diode are provided on different substrates.   2. The optical disc apparatus according to claim 1, wherein the optical pickup is moved and displaced together with the tray, and when the tray is in the second position, the objective lens position is outside the apparatus main body.

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