JPH06333245A - Optical disk device - Google Patents

Abstract

PURPOSE:To surely control an actuator and to move an optical pick-up to a target position even when a position detecting means is omitted by switching the operation of a drive coil at a specified cycle on a moving mode, detecting the moving speed of the optical pick-up based on the terminal voltage of the drive coil and driving the drive coil based on the moving speed. CONSTITUTION:The contact point of a selection circuit 6 is switched based on a switching signal of a specified cycle S1 and the terminal voltage of a drive coil 12 is outputted to a switch circuit 8 via an amplifier circuit 7 for a specified period of time. From the circuit 8 it is inputted to an amplifier circuit 10 by a switching signal S2. At a phase compensation circuit 11, after a voltage differing from a specified instruction voltage from the circuit 10 is phase-compensated, it is outputted to amplifiers 4 and 5 via a selection circuit 3 at the time other than a tracking control. Thus, the coil 12 is driven so that the moving speed of an optical pick-up 2 is made to a specified one and the position detecting means is made unnecessary.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems (FIGS. 1 and 2) Action (FIGS. 1 and 2) Example (1) Configuration of Example (FIGS. 1 and 2) (Fig. 2) (2) Effect of the embodiment (3) Other embodiment Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device,
For example, the present invention can be applied to an optical disc device that moves a optical pickup in the radial direction of the optical disc to access a desired recording track.

[0003]

2. Description of the Related Art Conventionally, in this type of optical disc device, an optical pickup is movable in a radial direction of the optical disc by driving a predetermined linear actuator.

That is, this type of optical disc device has a predetermined guide rod extending in the radial direction of the optical disc, and slidably holds the optical pickup along the guide rod. Further, the optical disc device is configured such that a light emitting diode is mounted on the optical pickup and a light receiving element for position detection is arranged along the guide rod, whereby the light receiving element receives light from the light emitting diode and outputs the light. The position of the pick-up can be detected.

On the other hand, the linear actuator is formed by a linear motor adapted to generate a driving force according to an applied current. In the optical disc device, a drive signal is generated based on the position detection result of the optical pickup and the linear actuator is driven by this drive signal, whereby the optical pickup is moved in the radial direction of the optical disc.

As a result, in the optical disc device, it is possible to seek the optical pickup at a high speed with a predetermined acceleration / deceleration characteristic based on the position detection result of the optical pickup. Further, at the time of start-up, when the optical disc is ejected, etc., the optical pickup can be moved and held at predetermined positions on the inner and outer peripheral sides based on the result of detecting the position of the optical pickup.

[0007]

By the way, in the optical disc device of this type, if the position detecting means of such an optical pickup can be omitted, the structure of the spectral disc device can be simplified.

After the access to the optical disk is started once, the optical disk apparatus detects the change in the tracking error signal because the focus searching is performed and the state of the focusing tracking is formed. The moving speed and moving distance of the optical pickup can be detected. Therefore, in this case, even if the position detecting means of the optical pickup is omitted, the optical pickup can be sought to the desired recording track.

However, since the focusing tracking control is not performed immediately before the focus search such as immediately after loading the optical disk, in the optical disk device, when the position detecting means of the optical pickup is omitted, the optical pickup is detected. The position cannot be detected correctly, and in this case, an open loop drive circuit is eventually formed to drive the linear actuator. In this case, in the optical disc device, it becomes difficult to move the optical pickup smoothly, and when the optical disc device is held tilted, the optical pickup cannot be correctly moved to the target position. There may be cases.

The present invention has been made in consideration of the above points, and an optical disc device capable of reliably controlling the actuator to move the optical pickup to a predetermined target position even if the position detecting means is omitted. It is a proposal.

[0011]

In order to solve the above problems, in the present invention, the optical pickup 2 is held in close proximity to the disk-shaped recording medium rotating at a predetermined rotation speed, and the optical pickup 2 is driven. In the optical disk device 1 for recording desired data on the disk-shaped recording medium or for reproducing the data recorded on the disk-shaped recording medium based on the reproduction signal output from the optical pickup 2, a magnetic field that forms a predetermined magnetic field is generated. Drive coil 12 held in the circuit
An actuator that moves the optical pickup 2 in the radial direction of the disk-shaped recording medium in accordance with a driving current applied to the contact, and a contact mode at a predetermined cycle in a movement mode in which the focus control is stopped to move the optical pickup 2 to a predetermined position. And a selection circuit 6 that applies a predetermined drive signal to the drive coil for a predetermined period T2 and outputs the terminal voltage of the drive coil 12 for a subsequent predetermined period T1. A drive signal generation circuit 7, 8, 9, 10, 11 for generating a drive signal based on the output terminal voltage of the drive coil 12 is provided.

Further, in the second invention, when the optical disc is loaded, the mode is switched to the moving mode, and the optical pickup 2 is moved to a predetermined position on the inner peripheral side of the optical disc.

Further, in the third invention, when the optical disc is ejected, the mode is switched to the moving mode, and the optical pickup 2
Is moved to a predetermined position on the outer peripheral side of the optical disc.

Further, in the fourth aspect of the present invention, when the objective lens mounted on the optical pickup 2 is cleaned, it is switched to the moving mode, and the optical pickup is attached to the inner and outer peripheral sides of the cleaning disk loaded in place of the optical disk. 2 is moved in a predetermined cycle.

[0015]

In the movement mode in which the focus control is stopped and the optical pickup 2 is moved to a predetermined position, a predetermined drive signal is applied to the drive coil for a predetermined period T2, and the drive coil is continued for a predetermined period T1. A selection circuit 6 that outputs a terminal voltage of 12 and drive signal generation circuits 7, 8, 9, 10, 11 that generate a drive signal based on the terminal voltage of the drive coil 12 output from the selection circuit 6 are provided. According to this, the operation of the drive coil 12 can be switched in a time division manner to detect the moving speed of the optical pickup 2, and the optical pickup 2 can be moved based on the detection result.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Configuration of Embodiment In FIG. 1, reference numeral 1 denotes an optical disk device as a whole,
The optical pickup 2 is moved in the radial direction of the optical disk to access the desired recording track.

Here, the optical pickup 2 emits a light beam from a built-in laser diode, and the light beam is condensed on an optical disk by an objective lens. Further, the optical pickup is configured such that the reflected light of the light beam is condensed by the objective lens and is received by a predetermined light receiving element, whereby the optical disc device 1 receives the tracking error signal TE and the focus error signal based on the light receiving result. It is adapted to generate a cass error signal. As a result, the optical disk device can drive the objective lens up and down based on the focus error signal to perform focus control.

Further, the optical disc device 1 amplifies the tracking error signal TE with a predetermined gain to compensate the phase, and then,
The signal is output to the tracking actuator incorporated in the optical pickup 2, and the amplifier circuit 4 is also supplied via the selection circuit 3.
And 5 are output. The amplifier circuits 4 and 5 output an output signal to the drive coil 12 of the linear actuator via the selection circuit 6, whereby the optical disk device 1 causes the tracking actuator and the linear actuator based on the tracking error signal. The actuator can be driven to perform tracking control.

On the other hand, the optical disk device 1 switches the contact of the selection circuit 6 at a predetermined cycle when moving the optical pickup to a predetermined reference position, and when cleaning the optical pickup, and thereby moves the optical pickup. It is designed to be able to do. That is, in the drive coil 12 of the linear actuator, by being held in a magnetic circuit configured to generate a predetermined magnetic field,
When the connection between the amplifier circuits 4 and 5 is separated and maintained, the terminal voltage can be detected to detect the moving speed of the optical pickup.

As a result, if the optical pickup 2 is moved so that the terminal voltage exhibits a predetermined change, the optical pickup 1 can be moved to a predetermined target position in the optical disc device 1. At this time, the drive coil 12
Operation is switched in time division, and the detection of this moving speed and the operation of driving the optical pickup 2 are the same.
If it is executed by using, the configuration of the spectral disk device 1 can be simplified.

Therefore, in this embodiment, the optical disk device 1 has a predetermined switching signal S1 as shown in FIG.
Based on the above, the contacts of the selection circuit 6 are switched in a predetermined cycle, and the terminal voltage of the drive coil 12 is output to the amplifier circuit 7 for a predetermined period T1 (FIG. 2 (A)). The amplifier circuit 7 inputs the terminal voltage of the drive coil 12 to the inverting input terminal and the non-inverting input terminal, amplifies it with a predetermined gain, and outputs it to the switch circuit 8.

The switch circuit 8 forms a sample and hold circuit together with the sample and hold capacitor 9, and switches to the ON state during the period T2 immediately before the period T1 ends based on the switching signal S2. The output signal of is sample-held in the sample-hold capacitor 9. In this embodiment, the optical disc device 1 switches the contacts of the selection circuit 6 in the period T1 and then
The period until the output signal of the amplifier circuit 7 is sample-held is sufficiently secured, and the counter electromotive voltage generated by stopping the driving of the drive coil 12 is sufficiently suppressed, and then the terminal voltage of the drive coil 12 is changed. It is designed to be able to hold a sample.

The amplifier circuit 10 has a sample-hold voltage of the sample-hold capacitor 9 and a predetermined instruction voltage S.
While the error voltage with respect to 3 is detected, the phase compensation circuit 11
Phase-compensates this error voltage, and then outputs it to the amplifier circuits 4 and 5 via the selection circuit 3.

In this way, the selection circuit 3 switches the contact between the tracking control and the time other than the tracking control, and outputs the tracking error signal to the amplifier circuits 4 and 5 during the tracking control, while the tracking control is performed. At times other than time, the output signal of the phase compensation circuit 11 is output to the amplifier circuits 4 and 5. As a result, during the subsequent period T3, the selection circuit 3 switches the contacts so as to output the output signals of the amplifier circuits 4 and 5 to the drive coil 12, whereby the optical disk device 1 uses the drive coil 12 and the period T1. During the subsequent period T3, the drive coil 12 is driven so that the moving speed becomes a predetermined speed based on the moving speed detection result of the optical pickup 2 detected during the period.

As a result, the optical disc device 1 can reliably control the linear actuator and move the pickup to a predetermined target position even if the position detecting means is omitted. That is, the optical disc device 1 moves the optical pickup 2 to a predetermined position on the inner circumference side of the optical disc when the optical disc is loaded and when the light amount is initialized and the irradiation of the light beam is stopped and controlled. Is started and a focus search is performed, whereby the light beam is irradiated to a preset test area and the light amount of the light beam is set.

Further, when confirming the operation of the laser drive system, the optical disc apparatus 1 similarly moves the optical pickup to the inner peripheral side of the optical disc, and confirms the operation by using this test area. That is, in the case of initializing the light quantity in this way, it is difficult to use the data area. Therefore, the light quantity of the light beam cannot be set to the light quantity at the time of reproduction. , There is a feature that cannot perform focus control by performing focus search.

Accordingly, in the optical disc device 1,
By switching the operation of the drive coil 12 in a time division manner, the optical pickup can be surely moved to the test area even if the position detecting means is omitted.

On the other hand, when the optical disc is ejected, the optical disc device 1 applies the same method to move the optical pickup 2 to a predetermined position on the outer peripheral side of the optical disc.
That is, in this case, in the optical disc device 1, the focus control is stopped and controlled to hold the objective lens at a position separated from the optical disc.

Therefore, in this case as well, there is a feature that the position and the moving speed of the optical pickup cannot be detected with reference to the tracking error signal. In this case, in the optical disc device 1, the operation of the drive coil 12 is time-divided. By switching, the optical pickup can be surely moved to the predetermined position on the outer peripheral side even if the position detecting means is omitted.

Further, the optical disk device 1 switches the polarity of the instruction voltage S3 in a predetermined cycle during cleaning of the optical pickup, thereby gently vibrating the optical pickup in this switching cycle. That is, at the time of cleaning the optical pickup, in the optical disk device 1, a cleaning disk having surface flocked is loaded in place of the normal optical disk, and the objective lens is cleaned with this flocking.

As a result, in the optical disc device, focus control cannot be performed in this case as well, whereby the operation of the drive coil 12 can be switched in a time division manner to surely vibrate the optical pickup.

On the other hand, the optical disk device 1 counts the change in the tracking error signal when the desired recording track is accessed after the normal operation mode is started, and thus the moving speed of the optical pickup is increased. And the moving distance is detected. Further, in this case, the optical disk device 1 obtains a difference signal between the moving speed detection result and a predetermined profile signal, and outputs the difference signal to the amplifier circuits 4 and 5 instead of the output signal of the phase compensation circuit 11.

(2) Effects of the Embodiments According to the above configuration, the operation of the drive coil 12 is switched in a time division manner, and the drive coil 12 is driven based on the moving speed of the optical pickup 2 detected by the drive coil 12. As a result, the optical pickup can be reliably moved to a desired position even if the position detecting means is omitted.

(3) Other Embodiments In the above embodiments, the case where the terminal voltage of the drive coil is processed by the analog signal has been described, but the present invention is not limited to this, and the digital signal processing may be performed. Good. That is, the drive coil 1 obtained via the amplifier circuit 7
The terminal voltage of 2 is converted into a digital signal by the analog digital conversion circuit and then output to the arithmetic processing circuit.

As a result, in the optical disc device, the arithmetic processing circuit generates a drive signal for the drive coil 12 so as to exhibit a predetermined change, and drives the drive coil 12 through a predetermined amplifier circuit. By doing so, tracking control can be performed at the same time by using this arithmetic processing circuit, and a drive signal of this kind can be easily generated.

Furthermore, in the above-described embodiment, the case where the contact of the selection circuit 6 is switched to switch the operation of the drive coil 12 in a time division manner has been described, but the present invention is not limited to this, and the amplification for driving the drive coil 12 is described. By applying an amplifier circuit having an enable terminal as a circuit, the voltage of the enable terminal can be switched to stop and control the operation of the amplifier circuit, and the amplifier circuit can also serve as the selection circuit 6.

Further, in the above-mentioned embodiment, the case where the linear actuator is used to move the optical pickup has been described. However, the present invention is not limited to this, and the optical pickup can be moved using various actuators. It can be widely applied in cases.

[0039]

As described above, according to the present invention, in the movement mode in which the focus control is stopped and the optical pickup is moved to a predetermined position, the operation of the drive coil is switched at a predetermined cycle, and the terminal voltage of the drive coil is changed. By detecting the moving speed of the optical pickup based on the above, and driving the drive coil based on the detection result, the actuator can be reliably controlled to move the optical pickup to a predetermined target position even if the position detection means is omitted. It is possible to obtain an optical disk device that can be operated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an optical disk device according to an embodiment of the present invention.

FIG. 2 is a signal waveform diagram for explaining the operation.

[Explanation of symbols]

1 ... Optical disk device, 2 ... Optical pickup, 3,6
…… Selection circuit 4, 5, 7, 10 …… Amplification circuit, 8 ……
Switch circuit, 9 ... Sample and hold capacitor, 1
2 ... Drive coil.

Claims (4)

[Claims] 1. An optical pick-up is held in close proximity to a disk-shaped recording medium rotating at a predetermined rotation speed, and the optical pick-up is driven to record desired data on the disk-shaped recording medium. In an optical disk device that reproduces data recorded on the disk-shaped recording medium based on a reproduction signal output from the optical pickup, the drive current applied to the drive coil is held by a magnetic circuit that forms a predetermined magnetic field. Accordingly, in the actuator for moving the optical pickup in the radial direction of the disk-shaped recording medium, and in the movement mode for stopping the focus control to move the optical pickup to a predetermined position, the contacts are switched at a predetermined cycle to set a predetermined period. A predetermined drive signal to the drive coil during the An optical disk, comprising: a selection circuit that outputs a voltage; and a drive signal generation circuit that generates the drive signal based on the terminal voltage of the drive coil output from the selection circuit in the movement mode. apparatus. 2. The optical disk according to claim 1, wherein, when the optical disk is loaded, the optical disk is switched to the moving mode and the optical pickup is moved to a predetermined position on the inner peripheral side of the optical disk. apparatus. 3. The optical disk is switched to the moving mode when the optical disk is ejected, and the optical pickup is moved to a predetermined position on the outer peripheral side of the optical disk.
Alternatively, the optical disk device according to claim 2. 4. When cleaning an objective lens mounted on the optical pickup, the optical pickup is switched to the moving mode and the cleaning pickup mounted in place of the optical disk is provided with the optical pickup at a predetermined cycle. The optical disk device according to claim 1, 2 or 3, wherein the optical disk device is movable by.