JPH0766623B2 - Disc recording information reproducing apparatus having CLV adaptive spindle control function in track jump repeat reproducing mode - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a spindle control method in an information recording disk reproducing apparatus.

BACKGROUND ART Disc reproduction for reproducing an information recording disc (hereinafter, simply referred to as a disc) such as a video disc or a digital audio disc on which a video signal containing video information such as a so-called composite video signal or a digital audio signal compressed on a time axis is recorded. In addition to the normal sequential reproduction mode, the device has a special so-called scan operation that requires a jump operation for jumping the spot light for reading the recorded information on the disc from one track to another track which is one track pitch or more apart. It generally has a playback mode.

In this disc reproducing apparatus, the reproduction signal obtained from the pickup has a fluctuation component on the time axis due to uneven rotation of the spindle motor that rotationally drives the disc. A so-called spindle servo is performed in order to suppress this time axis fluctuation. In order to make this spindle servo, a reproduction synchronization signal such as a horizontal synchronization pulse is extracted from the reproduction video signal, and the phase difference between this reproduction synchronization signal and the reference synchronization signal generated in the device is detected. It has been conventionally practiced to control the rotational speed of a spindle motor so that the phase difference becomes small. Also, when performing a jump operation, the so-called tracking servo servo loop that controls the spot light to follow the recording track of the disc becomes open during the jump period, and the reproduction synchronization signal cannot be obtained. Conventionally, no control regarding the spindle servo has been performed during this period.

In such a disc reproducing apparatus, so-called CLV (Const
ant Linear Velocity) When playing a disc and performing a jump operation, in the CLV disc, the disc rotation speed changes according to the disc radial position of the pickup, so no control is performed during the tracking servo loop open period. In the conventional control method in which the servo pull-in is started after the loop is closed, it takes a considerably long time to stabilize the spindle servo system.

SUMMARY OF THE INVENTION Therefore, the present invention provides a spindle control method capable of shortening the pull-in time of a servo system after a jump operation in a disc on which information is recorded while changing the recording angular velocity, such as a CLV disc. With the goal.

A disc recording information reproducing apparatus having a CLV adaptive spindle control function in a track jump repetitive reproducing mode according to the present invention comprises a pickup for reading recorded information of a CLV type information recording disc at an information detection point, and the pickup in the radial direction of the disc. Moving means for moving, a tracking servo means for biasing the information detection point in a direction orthogonal to the recording track of the disc so that the information detection point follows the recording track of the disc based on the read output of the pickup, and reading of the pickup Disc recording information reproduction including a spindle servo loop that controls the rotation of a spindle motor that rotationally drives the disc in accordance with a phase and frequency error between a reproduction synchronization signal included in the output and a reference synchronization signal having a predetermined frequency and phase A device, The pickup position detecting means for detecting the position of the pickup in the radial direction of the disc, and the moving means for moving the pickup at a predetermined speed in the track jump repeat reproduction mode, and the tracking servo means for detecting the information. The spindle servo loop is opened only during the period from the point reaching the predetermined bias position to the predetermined return position to accelerate or decelerate the spindle motor according to the moving direction information of the pickup and detect the pickup position. Control means for controlling rotation so as to change the acceleration according to the position information detected by the means.

Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a spindle servo device according to the present invention. In the figure, a video disk 1 is rotationally driven by a spindle motor 2, and its recorded information is read by a pickup 3. The tracking servo circuit 4 positions the pickup 3 in the disk radial direction so as to follow a desired track. The tracking servo circuit 4 uses the pickup 3 in the special reproduction mode that requires a jump operation such as scanning.
The information reading spot light emitted from the device is controlled so as to jump in response to a command from a control circuit (not shown), and an information signal indicating the open / closed state of the servo loop, an information signal indicating the moving direction of the pickup 3, etc. Is output. As an example of the configuration, the one disclosed in Japanese Utility Model Publication No. 57-33435 is known.

The read information from the pickup 3 is demodulated by the demodulation circuit 5 and becomes a video signal. This video signal is supplied to the image reproducing system for reproduction processing, but since the configuration of this image reproducing system is well known, its explanation is omitted here. The reproduced video signal is also supplied to the sync separation circuit 6. The sync separation circuit 6 separates and extracts a reproduction sync signal such as a horizontal sync pulse included in the reproduction video signal. The extracted reproduction synchronization signal becomes one input of each of the phase error detection circuit 7 and the frequency error detection circuit 8, and is also supplied to the initialization signal generation circuit 9. On the other hand, the reference synchronization signal of a predetermined frequency generated from the reference synchronization generation circuit 10 is supplied to each of the other inputs of the phase error detection circuit 7 and the frequency error detection circuit 8.

The phase error detection circuit 7 detects a phase difference between the reference synchronization signal and the reproduction synchronization signal, generates a phase difference signal representing this phase difference, and inputs it to one input of the selection switch 12 via the equalizer circuit 11. On the other hand, the frequency error detection circuit 8 detects the frequency difference between the reference synchronization signal and the reproduction synchronization signal and generates a frequency difference signal representing this frequency difference. This frequency difference signal becomes the other input of the selection switch 12 via the equalizer circuit 13, and also becomes the input of the direct frequency lock detection circuit 14. The frequency lock detection circuit 14 detects that the frequency difference signal level is equal to or lower than a predetermined level, that is, the frequency difference between the reference synchronization signal and the reproduction synchronization signal is equal to or lower than a predetermined value, and generates a detection signal, and an initialization signal generation circuit. 9 and the selection switch 12.

The initialization signal generation circuit 9 generates a reset pulse having a pulse width of an interval from the generation time point of the detection output from the frequency lock detection circuit 14 to the generation time point of the reproduction synchronization signal generated next, and generates the reference synchronization generation. Reset (initialize) the circuit 10. The selection switch 12 outputs the phase difference signal from the phase error detection circuit 7 when the detection signal is generated from the frequency lock detection circuit 14 and the frequency difference signal from the frequency error detection circuit 8 when the detection signal is not generated. Select each and output. The phase difference signal or the frequency difference signal selected by the selection switch 12 becomes one input of the selection switch 15.

The open control circuit 16 generates a drive signal based on the position information of the pickup 3 in the disk radial direction and the movement direction information of the pickup 3 and inputs the drive signal to the other input of the selection switch 15. The position information of the pickup 3 in the radial direction of the disk can be obtained from the cycle of the FG pulse generated from the frequency generator (FG) 17 that works in conjunction with the spindle motor 2. That is, in the case of CLV disc reproduction, since the rotation speed of the disc 1 changes according to the disc radial position of the pickup 3, the disc radial position of the pickup 3 and the cycle of the FG pulse (the rotation number of the spindle motor 2) have a corresponding relationship. It is in translation. The movement direction information of the pickup 3 can be obtained from the jump direction (forward direction or reverse direction) information in the tracking servo circuit 4.

The open control circuit 16 generates a motor drive signal that keeps the disk linear velocity at the pickup position constant.
In order for the disc linear velocity at the pickup position to be constant when the pickup 3 moves in the disc radial direction, the angular acceleration α of the disc 1 must take the value of the following equation.

α == − v _l · v _r / r ² = −v _r · ω ² / v _l where ω = v _l / r dω / dr = −v _l / r ² dr / dt = v _r dω / dt = −v _l · v _r / r ² . Here, v _l is the disc linear velocity at the pickup position, vr is the moving velocity of the pickup 3, r is the disc radial position of the pickup 3, and ω is the angular velocity of the disc 1.

The torque T to be generated by the spindle motor 2 to have this angular acceleration α is obtained from the following equation.

T = Jα = −Jv _r ω ² / v _l Here, J is the inertia ratio of the rotating body of the spindle motor 2. ω is obtained from the cycle of the FG pulse. Where v _l
And J are constants, and v _r can be regarded as a constant which is determined by the tracking servo system and whose sign is inverted depending on the moving direction of the pickup 3. From this, the torque T
Is calculated by the following equation.

T = Kω ² (K: constant) Thus, in the open control circuit 16, the pickup 3
Tracking servo circuit 4 at a level according to the period of the FG pulse, which is the disk radial position information of
A drive signal having a polarity corresponding to the moving direction information from is generated. In other words, the spindle motor drive signal decelerates the spindle motor if the pickup 3 is in the forward direction and accelerates the spindle motor in the reverse direction, and if the disc radial position of the pickup 3 is closer to the inner circumference. The acceleration (including negative acceleration) in acceleration / deceleration is increased, and it is decreased when the acceleration is closer to the outer circumference. As the configuration of the open control circuit 16, for example, as shown in FIG. 5, after the FG pulse is converted into a voltage by the F / V converter 20 and the level is set by the level setting circuit 21, the tracking servo circuit 4 outputs the voltage. By determining the polarity in the polarity reversing circuit 22 according to the moving direction information
It is possible to obtain a drive signal that continuously changes according to the cycle of the FG pulse, but the present invention is not limited to this.
An appropriate level may be selected according to the pulse cycle.

The servo loop in the tracking servo circuit 4 is, for example, from a time point when an actuator (not shown) for biasing the spot light in the disk radial direction reaches a predetermined swing position (spot light is a predetermined bias position), to a neutral position (spot light is It remains open until it returns to the vicinity of the predetermined return position), and the tracking servo circuit 4 generates a control signal that is high level when the tracking servo loop is open and low level when the tracking servo loop is closed and is supplied to the selection switch 15. It The selection switch 15 selects the phase difference signal or the frequency difference signal supplied through the selection switch 12 when this control signal is at a low level, and selects the drive signal output from the open control circuit 16 when this control signal is at a high level, Motor drive circuit 18 for driving the motor 2
Supply to. The open / close timing of the tracking servo loop corresponds to the open / close timing of the spindle servo loop.

Next, the servo pull-in operation at the time of scanning in CLV disk reproduction by the spindle servo device of such a configuration,
A description will be given according to the flowchart of FIG. 2 with reference to the waveform chart of FIG. The waveform diagrams (A) to (F) of FIG.
Correspond to the output signals (A) to (F) of the respective parts in FIG.

First, when a slider (not shown) equipped with the pickup 3 is moved in the disc radial direction at a predetermined speed in response to a scan command, an actuator (not shown) built in the pickup 3 causes spot light to emit spot light to a recording track of the disc 1. In this state, the tracking servo loop is in the closed state and the frequency difference between the reference synchronization signal and the reproduction synchronization signal is below a predetermined value. Therefore, in the selection switches 12 and 15,
The phase difference signal output from the phase error detection circuit 7 is selected, and so-called phase control is performed to drive and control the spindle motor 3 according to this phase difference signal (step 1).

When the actuator of the pickup 3 reaches a predetermined swing position (spot light is a predetermined bias position), the tracking servo loop is opened (step 2), and the tracking servo circuit 4 generates a high level control signal (C). The selection switch 15 selects the drive signal (D) generated from the open control circuit 16 during the generation period of the control signal and supplies it to the spindle motor 2 via the motor drive circuit 18. As a result, so-called open control is performed to drive and control the spindle motor 2 based on the position information of the pickup 3 in the disc radial direction and the movement direction information of the pickup 3 (step 3). in this way,
By controlling the spindle motor 2 based on the position information and the moving direction information of the pickup 3 during the open period of the tracking servo loop, the rotation speed of the spindle motor 2 is preset to a value near the rotation speed when the tracking servo loop is closed. Since the setting is made, it is possible to easily and quickly pull in the spindle servo after the tracking servo loop is closed.

When the tracking servo loop is opened, the actuator returns to the vicinity of the neutral position (the spot light is a predetermined returning position) due to the restoring force of the elastic support body, and then the tracking servo loop is closed again. The spot light jumps a predetermined number of recording tracks during the open period of the tracking servo loop. When the tracking servo loop is closed again (step 4), a low level control signal (C) is generated from the tracking servo circuit 4, and the selection switch 15 selects the output of the selection switch 12 in response to this control signal. Will be done. In addition, the frequency is unlocked from the time the tracking servo loop is opened (the frequency difference between the reference sync signal and the playback sync signal is greater than the specified value).
Since the detection output (A) of the frequency lock detection circuit 14 is at a low level, the selection switch 12 selects the frequency difference signal (E) output from the frequency error detection circuit 8, and the selection switch 15 and the motor drive. It is supplied to the spindle motor 2 via the circuit 18. As a result, so-called frequency control is performed to drive and control the spindle motor 3 according to the frequency difference signal (step 5). When the frequency difference between the reference synchronization signal and the reproduction synchronization signal becomes equal to or less than the predetermined value by this frequency control, this is detected by the frequency lock detection circuit 14 (step 6). At this time, the initialization signal generation circuit 9 generates a reset pulse (B) to initialize the phase of the reference synchronization signal.

The initialization operation will be described in detail with reference to the waveform diagram of FIG.
Generating a reset pulse (c) having a pulse width t at an interval from the generation time point of the detection output (a) from 14 to the generation time point of the next reproduction synchronization signal (b) (rising edge of the pulse), The so-called reference synchronization signal phase is supplied to the reference synchronization generation circuit 10 to reset the reference synchronization signal (d) so that the phase of the reference synchronization signal matches the phase of the reproduction synchronization signal (so-called initialization of the phase of the reference synchronization signal). In addition, in FIG. 4D, a waveform when not reset is shown by a broken line.

Further, when the detection output (A) is generated from the frequency lock detection circuit 14, the selection switch 12 selects the phase difference signal (F), so that the phase control is performed again after the initialization of the phase of the reference synchronization signal. (Step 1). In this way, by initializing the phase of the reference synchronization signal and then shifting to the phase control, the phase of the reference synchronization signal and the phase of the reproduction synchronization signal have already matched, so it is possible to reliably pull in the phase. And it can be done quickly.

In the above embodiment, the description has been given of the case where the servo pull-in operation at the time of scanning in the CLV disk reproduction is performed by the hardware configuration, but the servo pull-in procedure shown in the flowchart of FIG. 2 is programmed in advance by using the microcomputer. However, it is also possible to execute the servo pull-in operation by software by a microcomputer.

As described above, according to the present invention, the spindle servo loop is opened and the spindle motor is moved in the pickup moving direction only until the information detection point reaches the predetermined return position after reaching the predetermined bias position. By accelerating or decelerating according to the information and controlling the rotation to change the acceleration according to the pickup position information, the rotation speed at the time of closing the spindle servo loop can be made approximately equal to the rotation speed corresponding to the playback start position. It is possible to shorten the pull-in time of the spindle servo in the mode in which the track jump operation such as time is repeated to intermittently read and reproduce the recorded information.

Moreover, according to the present invention, the spindle servo loop is interlocked with the ON / OFF of the tracking servo during the mode 1 so that the spindle servo loop is opened each time so that the linear velocity of the CLV disk is regulated. Therefore, for example, even if a mode operation stop command is forcibly issued by an interrupt in the middle of the mode, it is possible to immediately and smoothly shift to appropriate rotation control at the pickup position. In addition, since the spindle control by the reproduction synchronization signal and the rotation control by the detected pickup position information (the open control) are repeated until the end of the mode, at the end of the mode, the rotation control by the detected pickup position information is largely performed. It has an advantage that there is no control error.

[Brief description of drawings]

FIG. 1 is a block diagram showing a spindle servo device according to the present invention, FIG. 2 is a flowchart showing an execution procedure of a spindle control method according to the present invention, and FIG. 3 is a first diagram for explaining a spindle servo pull-in operation. Waveform diagram of each part of
FIG. 4 is a waveform diagram of each part in FIG. 1 for explaining the initialization operation of the reference synchronization signal, and FIG. 5 is a block diagram showing an example of the configuration of the open control circuit in FIG. Description of symbols of main parts 1 ... Disk, 2 ... Spindle motor 3 ... Pickup 4 ... Tracking servo circuit 7 ... Phase error detection circuit 8 ... Frequency error detection circuit 9 ... Initialization signal generation circuit 10 ... … Reference synchronization generation circuit 12,15 …… Selection switch 14 …… Frequency lock detection circuit 16 …… Open control circuit

Claims (3)

[Claims] 1. A pickup for reading information recorded on a CLV type information recording disc at an information detection point, and a moving means for moving the pickup in a radial direction of the disc.
Tracking servo means for biasing the information detection point in the direction orthogonal to the recording track so that the information detection point follows the recording track of the disc based on the reading output of the pickup, and the reproduction included in the reading output of the pickup. A disc recording information reproducing device including a spindle servo loop for controlling rotation of a spindle motor that rotationally drives the disc according to a phase error and a frequency error between a sync signal and a reference sync signal having a predetermined frequency and a phase, Pickup position detecting means for detecting the position of the pickup in the radial direction of the disc; and, in the track jump repeat reproduction mode, the moving means for moving the pickup at a predetermined speed, and the tracking servo means for detecting the information detecting point. Is predetermined The spindle servo loop is opened only after reaching the predetermined position until reaching the predetermined return position, to accelerate or decelerate the spindle motor according to the moving direction information of the pickup and to detect it by the pickup position detecting means. And a control means for controlling rotation so as to change the acceleration according to the generated position information, and a disc recording information reproducing device having a CLV adaptive spindle control function in a track jump repeat reproducing mode. 2. The pickup position detecting means obtains the position information by calculating from the rotational speed information of the spindle motor based on the relationship between the radial position of the disk and the recording angular velocity in the predetermined recording information. A disk recording information reproducing apparatus having a CLV adaptive spindle control function in the track jump repeat reproducing mode according to claim 1. 3. The disk recording information reproducing apparatus having a CLV adaptive spindle control function in the track jump repeat reproducing mode according to claim 1, wherein the moving direction information is obtained from the tracking servo means. .