JP3813826B2 - Optical disk drive apparatus, optical disk apparatus and method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk drive apparatus and an optical disk recording / reproducing apparatus, and more particularly to improvement of focus servo control.
[0002]
[Prior art]
Recently, an optical disc recording / reproducing apparatus that records and reproduces data on an optical disc such as a DVD (Digital Versatile Disc) or a CD (Compact Disc) has been developed and widely spread. In such an optical disc recording / reproducing apparatus, a signal recording layer of an optical disc is irradiated with a laser beam, reflected light from the signal recording layer is received, and recorded information on the optical disc is reproduced based on the reflected light. . Such an optical disc apparatus is provided with a pickup having an actuator that moves the focal point of the laser beam to the signal recording layer of the optical disc by moving the objective lens to the optical disc and moving in the focus direction. Yes.
[0003]
The actuator has a drive coil in the focus direction and a drive coil in the track direction, and the tracking error signal and the focus error signal are based on the signals reproduced from the reflected light from the signal recording layer in order to servo-control each of them. Generated. When these tracking error signal and focus error signal are respectively supplied to the track servo amplifier and the focus servo amplifier via the RF amplifier, the tracking error signal and the focus error signal correspond to the required drive amounts of the focus direction drive coil and the track direction drive coil. A signal is determined and supplied to the track actuator driver and the focus actuator driver. As a result, each drive coil is appropriately shifted according to the drive current from each driver, so that the error in the track direction and the error in the focus direction are eliminated, and servo control in each direction of the actuator is established.
[0004]
[Problems to be solved by the invention]
However, when the pickup seeks over a plurality of tracks in the optical disc apparatus, the tracking error signal component flows into the focus servo control system, and the focus servo control system tries to suppress the leakage component. Occurs. Thereby, there is a problem that problems such as increase in power consumption and generation of noise occur.
[0005]
The present invention uses an optical disc drive apparatus having a focus servo control function that reduces power consumption and noise by suppressing a leak component to a focus servo control system of a tracking error signal when seeking an optical disc apparatus, and the same An object is to provide an optical disk device.
[0006]
[Means for Solving the Problems]
The present invention relates to a disk reproducing apparatus for reproducing data recorded on the basis of reflected light received by rotating an optical disk having a plurality of tracks at a predetermined speed and irradiating the signal recording layer with a laser beam.
A rotating means for rotating the optical disc at a predetermined number of revolutions;
Irradiating means for irradiating a predetermined area of the optical disc rotated by the rotating means via an actuator provided in a pickup; and
Generating means for receiving reflected light by irradiation of the irradiating means and generating a tracking error signal and a focus error signal according to the received light;
Moving means for seek-moving the pickup across a plurality of tracks on the optical disc in accordance with a given command;
Track control means for servo-controlling the actuator in the track direction based on the tracking error signal generated by the generation means;
A focus control unit that servo-controls the actuator in a focus direction based on a tracking error signal and a focus error signal generated by the generation unit when the moving unit performs seek movement of the pickup; The means obtains the value of the focus signal by a value obtained by dividing the value of the focus signal by the value of the tracking error signal generated by the generating means when the moving means performs the seek movement of the pickup, and based on the product of this value and a predetermined value Focus control means for servo-controlling the actuator in the focus direction;
Receiving means for receiving the reflected light of the laser beam irradiated by the irradiation means via the actuator controlled in operation by the track control means and the focus control means, detecting data based on the reflected light, and reproducing it. An optical disc reproducing apparatus characterized by the above.
[0007]
According to the present invention, the focus control means is a product of a value obtained by dividing the value of the tracking error signal generated by the generation means by the value of the focus signal when the movement means performs the seek movement of the pickup. Based on the above, the optical disk drive is characterized in that it is means for servo-controlling the actuator in the focus direction.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of an optical disk device according to the present invention, and FIG. 2 is a cross-sectional view showing the structure of an example of an optical pickup device of the optical disk device according to the present invention.
[0009]
In the optical disk apparatus according to the present invention, in FIG. 1, a signal read from the disk D driven by the disk motor 1 by the optical pickup 2 is supplied to the RF amplifiers 3-1 to 3. The RF amplifier 3-1 supplies the RF signal amplified from the output of the optical pickup 2 to the demodulator 5 of the signal processing unit 4. Further, the RF amplifier 3-2 extracts the focus error signal FE, and the RF amplifier 3-3 extracts the tracking error signal TE and supplies them to the tracking servo amplifier 21 and the focus servo amplifier 22, respectively. It should be noted here that the tracking error signal, which is a feature of the present invention, is also supplied to the focus servo amplifier. This suppresses the tracking error signal from leaking into the focus servo system control during a seek operation described later. Further, the control signal supplied from the tracking servo amplifier 21 is supplied to the tracking actuator driver 23, and the control signal supplied from the focus servo amplifier is output to the focus actuator driver 24. The outputs of the drivers 23 and 24 are returned to the pickup 2 and supplied to a drive coil 40 in the track direction and a drive coil 41 in the focus direction, which will be described later, to drive them and perform servo control.
[0010]
The signal processing unit 4 includes a demodulation unit 5 and a modulation unit 6. Under the control of the control unit by the CPU 13, the RAM 11, and the ROM 12, the demodulation unit 5 is detected by the optical pickup 2 and appropriately detected by the RF amplifier 3-1. The signal supplied after amplification is demodulated into a reproducible signal form, and this is supplied to a processing device such as an external host computer via the I / F 8. The modulation unit 6 included in the signal processing unit 4 modulates, for example, a signal given from the external host computer 10 or the like via the I / F 8 into a signal form that can be recorded on the optical disc D. The modulated signal is reflected on a laser beam generated from a semiconductor laser 35 (to be described later) of the pickup 2 via the RF amplifier 3-1, and is irradiated onto a predetermined area of the optical disk, and is reproduced as reproducible information to the predetermined area. To be recorded.
[0011]
Further, the seek servo control unit 7 performs servo control when the pickup is seek-operated by the feed motor 25 over a plurality of tracks on the optical disc D under the control of the control unit including the CPU 13, the RAM 11, and the ROM 12. Therefore, the drive current is supplied to the feed motor 25. Further, under the control of the control unit by the CPU 13, the RAM 11, and the ROM 12, the optical disk D is rotated at a rotation speed corresponding to the given optical disk D by servo control by the disk motor driver 27.
[0012]
The control unit makes an operation determination by the CPU 13 according to the operation program stored in the RAM 11 and the ROM 12, and controls the entire processing operation with reference to information from each unit.
[0013]
The I / F 8 performs communication control related to the interface such as transmission and reception of various operation commands and data with the host computer 10. The operation command is exchanged between the control unit and the host computer 10 via the I / F 8. However, the optical disk apparatus may be operated by an operation panel (not shown), and is not necessarily limited to this form.
[0014]
Further, in FIG. 2, the pickup device 2 has an actuator 39 for holding the objective lens. The actuator 39 is provided with a drive coil 40 for the actuator in the track direction and a drive coil 41 for the actuator in the focus direction. Servo control is enabled by supplying drive currents from the tracking actuator driver 23 and the focus actuator driver 24, respectively.
[0015]
The pickup device 2 performs both irradiation and light reception by the action of the beam splitter 37 and the like. Laser light irradiation from the semiconductor laser 35 according to the control of the control unit passes through the beam splitter 37, is condensed by the objective lens via the quarter-wave plate 38 and the like, and is irradiated onto a predetermined region of the optical disc D. Further, the reflected light from the optical disk D is expanded by the objective lens, separated to the condensing lens 34 side by the beam splitter 37, and further supplied to the two photodiodes 31 and 32 by the reflecting mirror 33. One photodiode 31 generates a tracking error signal by a comparator (not shown) and supplies the tracking error signal to the tracking servo amplifier 21 and the focus servo amplifier 22. In the other photodiode 32, a focus error signal is generated by a comparator (not shown), supplied to the focus servo amplifier 21, and simultaneously supplied to the RF amplifier 3-1 for generation of a reproduction signal.
[0016]
Such an optical disc apparatus according to the present invention detects the storage information stored in the storage area on the optical disc as described above, reproduces it, and performs the modulation operation based on the given signal, and then performs the modulation operation. The focus servo control operation, which is a feature of the present invention, will be described below with reference to the drawings. FIG. 3 is a graph for explaining an example of the relationship between the focus control and the tracking error signal of the optical disk apparatus according to the present invention. FIG. 4 is a graph showing the relationship between the focus control and the tracking error signal of the optical disk apparatus when the present invention is not used. It is a graph explaining an example of a relationship.
[0017]
In the focus servo control of the optical disc apparatus according to the present invention, the servo control operation is performed in consideration of not only the focus error signal FE but also the tracking error signal TE only during the period of the seek operation. Therefore, the tracking error signal TE is further supplied from the RF amplifier 3-2, and the focus error signal FE is further supplied from the RF amplifier 3-3. Further, the seek servo control unit 7 supplies a seek control signal as to whether or not the seek operation is being performed. Is done. Thus, during normal operation, focus servo control is performed based on only the focus error signal FE as usual, and when seek operation is performed, focus servo control is performed based on both the focus error signal FE and the tracking error signal TE. Is done.
[0018]
At this time, the control amount of the focus servo control is determined by the following method as an example.
1. In a state where only the focus servo is operated, a component that is synchronized with the track error signal and is higher than the focus servo band is extracted, and this amplitude is defined as Fcross.
2. Assuming that the amplitude of the tracking error signal at that time is TEmax, the compensation amount is set to 1/4 * Fcross / TEmax to 3/4 * Fcross / TEmax.
[0019]
By performing the focus servo control with such a compensation amount, it is possible to eliminate the component of the tracking error signal during the seek operation, and to reduce the power consumption during the seek and prevent noise.
[0020]
In this way, in order to eliminate the tracking error signal component during the seek operation, if the focus error control element is incorporated into the focus error control system during the seek operation and the focus control is performed, the method and value are not limited to those described above. The effect can be expected.
[0021]
In FIG. 3, (a) shows the waveform of the tracking error, and (b) shows the waveform of the focus signal before processing. It can be seen that the focus servo control is affected by the tracking error. By applying this processing to the above, it is possible to improve to a state where the influence of the tracking error as shown in (c) is eliminated. (D) is a graph which shows the focus electric current by the focus servo control which performed the process which this invention provides.
[0022]
4A is a graph showing the waveform of the tracking error signal, FIG. 4B is a graph showing the focus error, and FIG. 4C is a graph showing the focus error when the seek operation is performed when the focus control of the present invention is not performed. It is a graph showing the focus current, and it can be seen that the influence of the tracking error signal appears in the focus servo control during the seek operation.
[0023]
Those skilled in the art can implement the present invention through the various embodiments described above. However, various modifications of these embodiments will be readily apparent to those skilled in the art, and the broad principles disclosed can be applied to various embodiments without inventive ability. is there. Thus, it goes without saying that the present invention covers a wide range that does not contradict the disclosed principle and novel features, and is not limited to the above-described embodiments.
[0024]
【The invention's effect】
As described above, according to the present invention, the focus control is performed in consideration of the tracking error signal during the seek operation, thereby suppressing the influence of the tracking error signal and preventing the increase in power consumption and stable focus servo control. Can be implemented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of an optical disc apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing a structure of an example of an optical pickup device of an optical disk device according to the present invention.
FIG. 3 is a graph illustrating an example of a relationship between focus control and a tracking error signal in the optical disc apparatus according to the present invention.
FIG. 4 is a graph illustrating an example of a relationship between focus control and a tracking error signal of an optical disc apparatus when the present invention is not used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Disc motor 2 ... Optical pick-up 3 ... RF amplifier 4 ... Signal processing device 5 ... Demodulator 6 ... Modulator 7 ... Seek Servo control unit 8 ... I / F
10 .... Host computer 11 .... RAM
12. ROM
13 ... CPU
21 ... Phase compensation servo amplifier 22 ... Focus servo amplifier 23 ... Actuator driver 24 ... Actuator driver 25 ... Feed motor 26 ... Feed motor driver 27 ... ... Disc motor driver 39... Actuator 40... Track direction actuator drive coil 41... Focus direction actuator drive coil

Claims (4)

In an optical disc driving apparatus for rotating an optical disc having a plurality of tracks at a predetermined speed, irradiating the signal recording layer with a laser beam and receiving the reflected light,
A rotating means for rotating the optical disc at a predetermined number of revolutions;
Irradiating means for irradiating a predetermined area of the optical disc rotated by the rotating means via an actuator provided in a pickup; and
Generating means for receiving reflected light by irradiation of the irradiating means and generating a tracking error signal and a focus error signal according to the received light;
Moving means for seek-moving the pickup across a plurality of tracks on the optical disc in accordance with a given command;
Track control means for servo-controlling the actuator in the track direction based on the tracking error signal generated by the generation means;
When the actuator is servo-controlled in the focus direction and the moving means performs seek movement of the pickup, a value obtained by dividing the value of the focus signal generated by the generating means by the value of the tracking error signal generated by the generating means An optical disc driving apparatus comprising: a focus control unit which is obtained and obtained based on a product of this value and a predetermined value . In a disk reproducing apparatus that rotates an optical disk having a plurality of tracks at a predetermined speed, reproduces data recorded based on reflected light received by irradiating a laser beam to the signal recording layer,
A rotating means for rotating the optical disc at a predetermined number of revolutions;
Irradiating means for irradiating a predetermined area of the optical disc rotated by the rotating means via an actuator provided in a pickup; and
Generating means for receiving reflected light by irradiation of the irradiating means and generating a tracking error signal and a focus error signal according to the received light;
Moving means for seek-moving the pickup across a plurality of tracks on the optical disc in accordance with a given command;
Track control means for servo-controlling the actuator in the track direction based on the tracking error signal generated by the generation means;
When the actuator is servo-controlled in the focus direction and the moving means performs seek movement of the pickup, a value obtained by dividing the value of the focus signal generated by the generating means by the value of the tracking error signal generated by the generating means A focus control means that is determined on the basis of a product of this value and a predetermined value;
Receiving means for receiving the reflected light of the laser beam irradiated by the irradiation means via the actuator controlled in operation by the track control means and the focus control means, detecting data based on the reflected light, and reproducing it. An optical disc reproducing apparatus characterized by the above. In an optical disc driving method for rotating an optical disc having a plurality of tracks at a predetermined speed, irradiating the signal recording layer with a laser beam and receiving the reflected light,
An irradiation step of irradiating a predetermined area of the optical disc rotated by a rotating means via an actuator provided in the pickup;
Receiving reflected light from the irradiation in the irradiation step, and generating a tracking error signal and a focus error signal in response thereto; and
A moving step of seeking and moving the pickup across a plurality of tracks on the optical disc in accordance with a given command;
A track control step of servo-controlling the actuator in the track direction based on the tracking error signal generated by the generation step;
The actuator servos the focus direction, when said moving means performs a seek movement of the pickup, obtains a value obtained by dividing the value of the focus signal wherein the generating the value of the generated Tracking Nguera signal, this value and a predetermined An optical disk driving method comprising a focus control step performed based on a product with a value . In an optical disk reproducing method of rotating an optical disk having a plurality of tracks at a predetermined speed and reproducing recorded data based on reflected light received by irradiating the signal recording layer with a laser beam,
An irradiation step of irradiating a predetermined region of the optical disc rotated by a rotating means via an actuator provided in a pickup;
Receiving reflected light from the irradiation in the irradiation step, and generating a tracking error signal and a focus error signal in response thereto; and
A moving step of seeking and moving the pickup across a plurality of tracks on the optical disc in accordance with a given command;
A track control step for servo-controlling the actuator in the track direction based on the tracking error signal generated in the generation step;
When the actuator is servo-controlled in the focus direction and the moving means performs seek movement of the pickup, a value obtained by dividing the value of the generated focus signal by the value of the generated tracking error signal is obtained, and this value and a predetermined value A focus control step based on the product of the value;
A reproducing step of receiving the reflected light of the laser beam irradiated in the irradiation step via the actuator controlled in operation by the track control step and the focus control step, detecting data based on the reflected light, and reproducing it; An optical disc reproducing method characterized by the above.

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