JP2005149537A - Disk reproduction drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk reproduction drive which improves its reliability by protecting the optical pickup against physical vibrations applied from the outside. <P>SOLUTION: The disk reproduction drive 6, when not reproducing a disk, makes on/off control according to the control signals SB1-SB4 from a system controller or the like and turns on only the transistors Q1 and Q3 or Q2 and Q4 of the output stage of a driver circuit 2 connected across the focusing coil and/or the tracking coil 1 of the optical pickup 8. Then it short-circuits the focusing coil and/or the tracking coil 1 to damp their motions by utilizing their counter-electromotive force generated by their electromagnetic induction when physically vibrated from the outside. Thus the vibrations of the optical pickup 8 are suppressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to protection means for protecting an optical pickup unit in a disk reproducing apparatus such as an MD, CD, CD-R, CD-RW, DVD, DVD-RAM from physical vibration due to disturbance.

  Unlike a home-use disc player, a vehicle-mounted disc player always receives considerably intense physical vibrations while the car is running even when the disc is not activated.

  In this regard, the playback unit installed in the disk playback device for in-vehicle audio equipment uses the tracking servo, focus servo, etc. to control the position of the optical pickup while the disk is running (during playback). Although there is no problem with protecting the optical pickup from mechanical vibration, when the disc is not activated (during non-playback), the optical pickup is moved to the inner peripheral end of the disc or played back. It is often held stationary at the stop position.

  For this reason, if physical vibrations due to disturbances (such as running of a car) continue to be applied to an in-vehicle disk reproducing device for a long time, disconnection due to metal fatigue may occur in the optical pickup unit.

  In order to improve the reliability of such in-vehicle audio equipment with respect to physical vibration, the standards for reliability tests against vibrations required by automobile manufacturers have become increasingly strict, and the optical pickup section of the currently used disk playback devices has become more strict. The current situation is that it is becoming unable to withstand.

  As one of the current vibration countermeasures, it is adopted to make the spring that supports the lens of the optical pickup section thick so that it can withstand vibration, but this countermeasure requires energy for control and improves the performance of the disk. It requires a lot of energy to produce and is difficult to design.

  In addition, as another vibration countermeasure, there is a countermeasure to prevent the metal fatigue as much as possible by devising the structure of the fulcrum of the spring supporting the lens of the optical pickup unit, but a sufficient improvement effect can be obtained. Not.

  In [Patent Document 1] below, the overall shape of the actuator part in the optical pickup part can be reduced in thickness and weight, and the temperature rise of the focus coil and tracking coil (hereinafter also collectively referred to as drive coil) and the actuator. With respect to the problem of providing a collision prevention device for an optical pickup unit that does not shorten the product life due to deformation of the member for supporting the unit and does not require a complicated configuration such as acceleration detection means, 4 discloses a technique of “a collision prevention device for an optical pickup unit” configured as described above.

  That is, in FIG. 4, an optical pickup unit 8 that is driven during activation and reproduction of a disk D has a magnet unit 11 fixed to its base, and an actuator unit 9 disposed inside the magnetic forming unit. The actuator portion 9 is held via a flexible support portion 13 that is cantilevered by a support portion 12, a lens 10 is attached to the center portion, and a drive coil 9a is provided around the actuator portion 9. As a circuit connected to the optical pickup unit 8, a control circuit unit a is configured by adding a “detection unit” and a new “control unit” to the conventional focus servo control circuit. When the actuator unit 9 is not driven for reproduction, a “detection means” that detects a back electromotive signal generated in the actuator unit 9 when the actuator unit 9 is driven by disturbance due to external vibration or the like; “Control means” for supplying a control signal to the actuator unit 9 so as to cancel the disturbance component detected by the “means”.

JP 2002-15445 A

  However, “detection means” for detecting a back electromotive signal generated in the actuator unit 9 with respect to the conventional focus servo control circuit described in [Patent Document 1], and a disturbance component detected by the “detection means” The control circuit unit a to which a new “control means” for supplying a control signal to the actuator unit 9 so as to cancel out the vibration is great as a vibration suppression effect, but the A / D conversion unit 16, the analog processing unit 15, Interpolation processing unit 18, waveform calculation unit 19, D / A conversion unit 20 and the like are required, and the circuit configuration is complicated, and the control itself is also complicated. As a result, even if the actuator unit 9 remains the same, a means for detecting and controlling physical vibration due to the disturbance is newly added and complicated, and an increase in cost is inevitable.

  In addition, a new problem may occur that pulse noise generated by the control operation jumps into the radio tuner circuit and the radio performance deteriorates.

  At present, other measures have been taken to reduce the vibration of the actuator section 9, and it is not so much a problem.

  The present invention has been made in view of the above circumstances, and has an extremely simple configuration, but effectively physical when the disk is not activated with respect to the optical pickup unit of the disk reproducing apparatus (during non-reproduction). It is an object of the present invention to provide a disk reproducing apparatus that is provided with a vibration suppressing means that suppresses and protects vibration, thereby preventing disconnection due to metal fatigue of the optical pickup portion and improving reliability.

The present invention
(1) In the disk reproducing apparatus, the optical pickup includes a mechanical shorting means for short-circuiting both terminals of the focus coil and / or the tracking coil of the optical pickup unit when the disk of the digital recording medium is not activated. Vibration suppression means for generating a braking force against the physical vibration received by the optical pickup unit by back electromotive force of electromagnetic induction generated in the focus coil and / or tracking coil by the physical vibration received by the unit. The above-described problem is achieved by providing a disc reproducing apparatus.
(2) In the disc reproducing apparatus, when the disc of the digital recording medium is not activated, the optical pickup unit is provided with electrical shorting means for short-circuiting the focus coil and / or tracking coil of the optical pickup unit. A disk comprising vibration suppression means for generating a braking force against physical vibration received by the optical pickup unit by back electromotive force of electromagnetic induction generated in the focus coil and / or tracking coil by physical vibration. By providing a playback device, the above-mentioned problem is achieved when a disc is not being played back.

  The disk reproducing apparatus according to the present invention is an electromagnetic induction generated in the coil itself by a mechanical short circuit or an electrical short circuit of the focus coil or tracking coil of the optical pickup unit when the disk is not activated as described above. Because it has vibration suppression means due to back electromotive force, it can prevent disconnection caused by metal fatigue due to physical vibration of the optical pickup part without changing the design of the optical pickup part and with a very simple configuration, and it is reliable. It has an excellent effect of improving.

  In particular, for an in-vehicle disk reproducing apparatus, a remarkable effect can be obtained in improving reliability by suppressing vibration.

  Embodiments of a disk reproducing apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a circuit diagram for explaining a first embodiment of a disk reproducing apparatus according to the present invention, and FIG. 2 is a plan view of the inside of the disk reproducing apparatus for explaining the first embodiment. is there. FIG. 3 is a circuit diagram for explaining a second embodiment of the disk reproducing apparatus according to the present invention.

  The greatest feature of the present invention is that when a disc such as a CD is not activated (during non-reproduction), at least one of a focus coil or a tracking coil that is a drive coil of an optical pickup unit, preferably both ends of both coils The child is put into a state equivalent to a short circuit or short circuit (referred to collectively as a short circuit), and a counter electromotive force generated by electromagnetic induction in the coil itself due to physical vibration due to a disturbance with respect to the vibration direction. The configuration is such that the braking force is always generated in the reverse direction to brake the vibration of the optical pickup unit. Since the points other than the circuit relating to the drive coil of the optical pickup section are the same as those of the conventional disk reproducing apparatus, the means for bringing the focus coil and / or tracking coil related to the present invention into a short state will be described.

Examples of means for shorting the focus coil and / or tracking coil include mechanical short-circuit means and electrical short-circuit means.
(Embodiment example of mechanical short-circuit means)
In FIG. 1 or FIG. 2, the disk reproducing device 7 includes both terminals of the focus coil and / or the tracking coil 1 of the optical pickup unit 8 during non-reproduction when a disk of a digital recording medium, for example, a compact disk (CD) is not activated. Mechanical short-circuiting means for turning on the switch SW1 inserted therebetween to make it short-circuited, and the reverse of the electromagnetic induction generated in the focus coil and / or the tracking coil 1 by the physical vibration received by the optical pickup unit 8 It is a structure provided with the vibration suppression means which generate | occur | produces the brake (braking force) to the direction opposite to the vibration direction with respect to the physical vibration which the said optical pick-up part 8 receives with an electromotive force.

For example, as shown in FIG. 2, the mechanism of the mechanical shorting means that switches the switch SW1 from OFF to ON to short-circuit the disk of the optical pickup unit 8 when the reproduction state is changed to the non-reproduction state. The switch SW1 can be mechanically turned on by bringing a part (switch contact portion) 8a of the optical pickup into contact with the switch SW1 such as a toggle switch when moving to the peripheral side, and the optical pickup unit is activated by starting the disk. It can be realized that the switch SW1 is turned OFF when the 8 is separated. 2 is a feed gear of the pickup unit 8, 3 is a pickup unit feed motor, and 2 in FIG. 1 is a driver circuit of the optical pickup unit 8.
(Embodiment example of electrical shorting means)
In FIG. 3, the disk reproducing device 6 is a bridge circuit at the output stage of the driver circuit 2 in the broken line frame as means for electrically shorting the focus coil and / or the tracking coil 1 of the optical pickup unit 8 during non-reproduction. It controls ON / OFF of output transistors (power MOSFETs, etc.) Q1 to Q4 that are configured.

  That is, a control signal from a system controller or the like not shown in the non-reproducing state of the disc so that only the output transistors Q1 and Q3 connected to both terminals of the focus coil or tracking coil 1 are turned on or only Q2 and Q4 are turned on. SB1 to SB4 are used for ON / OFF control, the coil 1 is short-circuited electrically, and the coil 1 is braked by the counter electromotive force generated by the electromagnetic induction of the coil itself due to the physical vibration of the coil 1. .

  The electrical shorting means is easily realized by software only by adding the program of the system controller that controls the driver circuit of the optical pickup unit 8, and therefore, compared with the mechanical shorting means that requires the addition of the switch SW1. This is advantageous in terms of cost. Further, since braking is applied regardless of the stop position of the optical pickup unit 8, there is an advantage that versatility is enhanced.

  As described above, the disk reproducing apparatus according to the present invention makes both the focus coil and tracking coil terminals of the optical pickup section short-circuited or equivalent to a short circuit when a disk such as a CD is not used, thereby causing physical vibration due to disturbance. By using the back electromotive force generated in the coil itself, the physical vibration is braked to protect the optical pickup portion from physical vibration, so that metal fatigue of the optical pickup portion is reduced.

  In addition, as a reminder, the description of the above embodiment has been made with an in-vehicle CD playback device that receives severe physical vibrations during traveling, but a disc playback device other than a CD is also within the range of the present invention. In addition, the vibration suppression means of the optical pickup unit against physical vibration due to disturbance according to the present invention is also effective in a portable disk reproducing apparatus that receives physical vibration when moving during non-reproduction. Needless to say.

1 is a circuit diagram for explaining a first embodiment of a disk reproducing apparatus according to the present invention; FIG. 1 is a plan view of the inside of a disc playback apparatus for explaining a first embodiment. FIG. It is a circuit diagram for demonstrating 2nd Embodiment of the disc reproducing | regenerating apparatus based on this invention. It is a circuit diagram for demonstrating the collision prevention apparatus of the optical pick-up part which is a well-known technique.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Focus coil and / or tracking coil 2 Driver circuit 3 Pickup part feed motor 4 Pickup part feed gear 6, 7 Disc reproducing apparatus 8 Optical pickup part 8a Part of optical pickup (switch contact part)
SW1 switches Q1, Q2, Q3, Q4 Output transistors SB1 to SB4 Control signal

Claims (2)

In a disc player,
Mechanical short means for short-circuiting both terminals of the focus coil and / or tracking coil of the optical pickup unit when the disk of the digital recording medium is not activated, and the physical vibration received by the optical pickup unit A disk reproducing apparatus comprising vibration suppression means for generating a braking force against physical vibration received by the optical pickup unit by a back electromotive force of electromagnetic induction generated in a focus coil and / or a tracking coil. In a disc player,
Electrical shorting means for short-circuiting both terminals of the focus coil and / or tracking coil of the optical pickup unit when the disk of the digital recording medium is not activated, and the physical vibration received by the optical pickup unit A disk reproducing apparatus comprising vibration suppression means for generating a braking force against physical vibration received by the optical pickup unit by a back electromotive force of electromagnetic induction generated in a focus coil and / or a tracking coil.

Images