JPH10106123A - Spindle control device for disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible good spindle control by preventing outputting of a count value more than a prescribed value to a decoder and preventing supplying of a contingent reproducing synchronizing signal in shortening a clear releasing period with a noise mixed clear input signal. SOLUTION: Read address signals ID1 and ID2 are supplied as trigger inputs to retriggerable monostable multivibrator MMVs 71 and 72, and high level signals are generated in outputs only in a prescribed time. When the trigger input is again performed during the above generating period, this generating period of the high level signal is further extended from a point of this input time. Output signals of the MMVs 71 and 72 are supplied via an OR gate 73 to a clear input CLR of a counter 74. When noise is mixed in a push-pull signal, high level duration of the clear input signal CLR to be supplied to the counter 74 does not last long, and hence clear releasing is shortly finished. Consequently, since the count value Q more than the prescribed value is never transferred to the decoder 75, the contingent reproducing synchronizing signal SYNC is not supplied to a frequency phase comparator 80 at all.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spindle control device for a disk player.

[0002]

2. Description of the Related Art A spindle control system having a basic configuration shown in FIG. 1 has been conventionally used as a technique for rotating an optically readable disk-shaped recording medium by CAV (Constant Angle Velocity). . In FIG. 1, a recording signal of a disk 1 is read by an optical pickup (not shown) while being rotated and driven by a spindle motor 2. The spindle motor 2 includes a unit that generates a pulse wave signal (FG pulse) having a frequency corresponding to the motor rotation speed, and supplies the generated FG pulse to the error generation circuit 3. The error generation circuit 3 is supplied with a reference clock having a predetermined frequency corresponding to the target motor rotation speed, detects an error relating to the frequency and phase between this clock and the FG pulse, and generates an error signal corresponding to the detection error. It is supplied to a drive circuit 6 via a pulse width modulation (PWM) device 4 and a low-pass filter (LPF) 5. Thus, the drive circuit 6 supplies the spindle motor 2 with a rotation drive signal corresponding to the error signal subjected to the PWM and from which only the low-frequency component is extracted, so that the error detected by the error generation circuit 3 becomes zero. Therefore, the spindle motor 2 is controlled so as to approach the target motor rotation speed and maintain the target motor rotation speed.

[0003] This technique is based on the actual rotation state of the motor 2, and the rotation of the disk 1 can be controlled by CAV irrespective of the read signal obtained from the disk 1. On the other hand, the disk 1 is moved to CLV (constant linear velocity).
: Constant Linear Velocity), it is necessary to rotate the drive in accordance with the read signal (or read position). In order to realize such rotation drive, usually,
A configuration is provided in which a synchronization signal synchronized with the data signal in the read signal is extracted from the frequency component of the read signal of the disk, and the rotation speed of the spindle motor is controlled so that the synchronization signal has a predetermined frequency.

On the other hand, when such a synchronization signal cannot be obtained, for example, at the initial stage of the rotation drive of the spindle motor or when the reading pickup is moved at a high speed, the next falling edge from the rising edge of the data signal in the reading signal. It is known that the maximum value of the interval to the edge (maximum inversion interval) is detected and spindle control is performed so that the maximum inversion interval becomes a predetermined value. This technology is
No. 71,269. Also, in this publication, in order to improve the deficiency of the spindle control based on the maximum inversion interval, instead of the maximum inversion interval, the interval from the rising edge of the data signal to the next rising edge and the next falling edge from the falling edge. A configuration is disclosed in which a maximum value or a minimum value (maximum period or minimum period) is detected among intervals to an edge, and spindle control is performed so that the maximum or minimum period becomes a predetermined value.

Today, digital video discs (hereinafter, referred to as digital video discs)
A high-density recording type disc called DVD) is being put to practical use. This DVD has various recording formats and reading formats, and one of them is a DVD-RAM (DVD-Random A) as an information rewritable disc.
ccess Memory). DVD
In a non-recorded state where no data is written or a partially recorded state where only a small amount of data is written to a so-called RAM type disk such as a RAM, there is no data signal to be detected because there is no data signal to be detected. Alternatively, because of the shortage, neither the maximum inversion interval nor the maximum / minimum period as described above can be detected. Therefore, according to the technique described in the above publication, it is impossible to control the rotation of the disk based on the read signal for the unrecorded / partially recorded RAM type disk.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been applied to a disk-shaped recording medium, particularly to an unrecorded / partially recorded RAM type disk.
An object of the present invention is to provide a spindle control device capable of performing good spindle control based on the read signal.

[0007]

According to the present invention, there is provided a spindle control apparatus for obtaining a read signal from a disk having an ID area in which a recording position information signal is preformatted at a predetermined time interval at a predetermined time interval. A spindle control device for a player, comprising: optical reading means for irradiating the disk with a light beam and receiving return light passing through a recording surface of the disk; and a time for the ID area based on a light reception output of the optical reading means. ID detecting means for generating a detection signal when detecting that the length is equal to or longer than a predetermined length, reference signal generating means for generating a reference signal, and a frequency and phase difference between the detection signal and the reference signal. Error generating means for generating a corresponding error signal; and driving means for rotating and driving the disk at a rotation speed corresponding to the error signal. It is characterized.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. First, an example of a recording format of a disk to be driven by the spindle control system according to the present invention will be described. FIG. 2 shows a recording format on the recording surface of the disk, and adopts a land / groove (L / G) recording method for recording data in both the groove portion (groove) 1G and the groove portion (land) 1L of the guide groove. Have been. Tracks formed by grooves 1G are hatched in the figure, and tracks formed by lands 1L are not provided. In this example, such land and groove track are connected for each rotation of the disk, and a single spiral land / groove (SS-L / G: Single Spiral-
Land / Groove) recording method is adopted. SS-L /
Regarding the G recording method, the IEICE Technical Report of IEI by Nakane et al. From the Institute of Electronics, Information and Communication Engineers.
CE. MR95-88, CPM95-126 (1996-02) "Single spiral-land groove recording access method" may be referred to.

The spiral track is divided into sectors (or blocks), and the recording position on the disk, such as the physical position of the succeeding or preceding sector on the disk, the sector number, or the position, is substantially defined at the dividing point. There are provided ID areas S0 to S7 for preformatting address information (hereinafter, referred to as ID), which is shown in a typical manner. These ID areas are arranged at equal intervals at the rotation angle of the disk as shown in the figure, and are formed at the same time length at a predetermined recording / reading rate.

The details of the ID area are shown in FIG. In FIG. 3, an ID region S0 corresponding to a coupling position between a groove and a land ID and an ID region S1 corresponding to a coupling position between a groove and a land are typically and schematically shown. The ID areas S0 and S1 are composed of a part for recording an ID and a part for not recording the ID, both of which are in the groove / land width and in the reading direction.
It has a length that divides the area into two, and is arranged in a staggered manner with a half track offset in the radial direction of the disc with respect to the track formed by the groove and the land.

The ID recording section is formed, for example, in a groove shape, and a pit row as a mark bearing a corresponding ID is formed on the main surface thereof. The ID non-recording portion has a mirror surface, and its height is, for example, equal to the surface of the land. ID
In the area S0, an ID recording portion which is first deviated by a half track toward the inner circumference of the disk is present on the virtual track T1 extending from the groove to the land along the reading direction, and then an ID recording portion which is deviated by a half track toward the outer circumference of the disk. On the virtual track T2 extending from the land to the groove along the reading direction, first, an ID recording portion which is deviated by half a track toward the outer periphery of the disk, and then an ID recording portion which is deviated by a half track toward the inner periphery of the disk. Present. On the other hand, the ID area S1 presents an ID recording portion on the virtual track T3 extending from groove to groove along the reading direction, first having a half track offset toward the outer circumference of the disk, and then having a half track offset toward the inner circumference of the disk. On the virtual track T4 extending from the land to the land along the reading direction, an ID recording portion which is first deviated by a half track toward the inner peripheral side of the disk and then is deviated by a half track toward the outer peripheral side of the disk. An ID recording unit is shown.

FIG. 4 shows a schematic configuration of a reading system in a disk player including a spindle control device according to an embodiment of the present invention. In FIG. 4, the optical pickup irradiates a disk with a light beam by a light source (not shown),
It has a photodetector 21 for receiving return light reflected or transmitted from the recording surface. This detector 21
The light-receiving surface is equally divided into four by two straight lines orthogonal to each other, and four independent light-receiving regions are defined. One of the divided straight lines 2L is set along the direction of the tangent T of the recording track of the disk. ing. Therefore, the four light receiving regions are divided into the light receiving regions 2a and 2b and the light receiving regions 2c and 2d, which are symmetric with each other, by the one dividing line 2L. The light receiving areas 2a and 2b individually perform photoelectric conversion according to the light receiving amount and the light receiving state, and supply the converted outputs to the adder 31, respectively.
The photoelectric conversion is individually performed in accordance with the light receiving amount and the light receiving state, and the converted output is supplied to the adder 32. Both outputs of the adder 31 and the adder 32 are further supplied to an adder 33, which generates a sum signal corresponding to the amount of received light and the state of light reception in all the light receiving areas, and as a read information signal (RF). The data is supplied to the data demodulator 40. The data demodulator 40 performs waveform equalization and A / D conversion on the read information signal.
(Analog / digital) conversion, and RLL (Run
The reproduction data is generated by performing predetermined demodulation such as cancellation of length limited coding, and is transferred to a data processing system or an information reproduction system (not shown).

The output signals of the adders 31 and 32 are also supplied to a subtractor 34. As a result, the output of the subtractor 34 outputs a so-called push-pull signal (P) corresponding to the difference between the light receiving outputs of the pair of light receiving regions symmetrical to the dividing line 2L.
P) is obtained. This push-pull signal is supplied to non-inverting inputs of differential amplifiers 51 and 52 as comparators. The inverting inputs of the differential amplifiers 51 and 52 have threshold values TH1,
Signals corresponding to TH2 are individually supplied. Differential amplifier 5
1 and 52 perform a level comparison between the corresponding threshold value and the push-pull signal, and supply signals corresponding to the comparison result to the address demodulator 60 as read address signals ID1 and ID2. The address demodulator 60 performs a predetermined demodulation on the read address signal to generate a reproduction address, and transfers this to an address processing system and a system control system (not shown).

Next, the details of a spindle control system according to an embodiment of the present invention will be described with reference to FIG. In FIG. 5, read address signals ID1 and ID2 are retrigable monostable multivibrators (MMV) 71 and 72.
Supplied as a trigger input. MMV71, 72,
In response to these trigger inputs, a high-level signal is generated at the output for a predetermined time. If a trigger input occurs again during the high-level generation period, the high-level signal generation period is extended again from that point by a predetermined time. It works as follows. MMV
Output signals of 71 and 72 are supplied to a clear input CLR of a counter 74 via an OR gate 73. Counter 7
4 sends the count output Q to the decoder 75, and the decoder 75 generates a detection signal, that is, a reproduction synchronization signal SYNC when the count output Q reaches a predetermined count value. The reproduction synchronization signal SYNC is supplied to the frequency / phase comparator 80
The frequency / phase comparator 80 detects an error related to the frequency and phase between the reference signal from the reference signal generation system and the reproduction synchronization signal SYNC, and outputs a rotation drive signal corresponding to the detected error to the spindle. Supply to motor 2.

The reference signal generation system includes a crystal oscillator 91, a first frequency divider 92, and a second frequency divider 93. The oscillation output signal of the crystal oscillator 91 is divided by a frequency divider 92 into 1 /
The frequency is divided into N (N is 1 or more real number), and the divided output signal is supplied to the clock input CK of the counter 74. The output signal of the frequency divider 92 is also supplied to a frequency divider 93, where it is frequency-divided to 1 / M (M is a real number equal to or greater than 1). The signals are supplied to a frequency / phase comparator 80 to be compared.

FIG. 6 shows the operation waveforms of the respective components of this configuration. The push-pull signal PP indicates the amount of deviation of the reading point (the irradiation position of the reading light beam spot on the disk recording) from the center of the land / groove track. Therefore, the push-pull signal PP is equivalent to a so-called tracking error signal.

When the reading point scans the virtual track T1 (see FIG. 3), the push-pull signal PP outputs the ID assigned to the virtual track as shown in FIG.
It has a wavy level having peaks and valleys corresponding to the pit rows formed in the recording section. The push-pull signal PP exhibits a wave train having a DC level more positive than the reference level by the preceding ID recording unit scanned by the reading point, and then by the subsequent ID recording unit scanned by the reading point. The wave train has a DC level of a negative polarity than the level.

The comparator 51 (see FIG. 4) has a threshold value TH1 sufficiently larger than the reference level of the push-pull signal PP.
And the comparator 52 generates a high-level signal when the level of the push-pull signal PP is higher than the threshold, and the comparator 52 inputs the threshold TH2 sufficiently lower than the reference level of the push-pull signal PP. And the push-pull signal P
When the level of P is smaller than the threshold, a low level signal is generated. Therefore, the push-pull signal PP
As shown in FIG. 6, the continuous wave trains of the preceding and succeeding ID recording units have rectangular read address signals ID.
1 and ID2.

Such read address signals ID1, ID
2 triggers the MMVs 71 and 72, respectively, by the rising or falling edge of the rectangular wave. As a result, a signal M1 exhibiting a high level is generated from the output of the MMV 71 from the first rising edge of the read address signal ID1 to a point in time after a lapse of a predetermined time from the last rising edge. A signal M2 exhibiting a high level is generated from the first falling edge of the signal ID2 to a point after a predetermined time has elapsed from the last falling edge. These signals M1 and M2 together become the clear input signal CLR of the counter 74 via the OR gate 73. Therefore, the clear input signal CLR corresponds to the scanning period of the ID recording section at the pickup information reading point.

Since the counter 74 performs a clear operation when the clear input is at a low level, the clear (reset) is released by a high-level clear input by the signals M1 and M2.
The count operation is enabled. Therefore, the counter 74
While the signals M1 and M2 are at the high level, the counting of the relatively high frequency clock signal (clock pulse) from the frequency divider 92 is continued. With this operation, the counter 74 increases the count value Q and outputs it to the decoder 75. The decoder 75 has a predetermined value QTH whose count value Q is relatively high.
If it becomes larger, the output is set to a high level and the reproduction synchronization signal SYNC is supplied to the frequency phase comparator 80. The frequency / phase comparator 80 generates a rotation drive signal based on the reproduction synchronization signal thus generated and the reference signal from the frequency divider 93, and supplies this to the spindle motor 2.

The spindle control according to the present embodiment as described above prevents a malfunction caused by noise generated in the push-pull signal PP. That is, as shown in FIG. 6, when noise is added to the push-pull signal PP, the clear input signal CLR supplied to the counter 74 is supplied.
The high level duration of the
Clearing ends in a short time. Therefore, the counter 74 does not transfer the count value Q larger than the predetermined value QTH to the decoder 75, so that the accidental reproduction synchronization signal SYNC is not supplied to the frequency phase comparator 80.

FIG. 7 shows a spindle control system according to another embodiment of the present invention, and the same parts as those in FIGS. 4 and 5 are denoted by the same reference numerals. 7, two input signals of the OR gate 73 for obtaining the clear input signal CLR of the counter 74 are generated by a configuration different from that of FIG. This configuration includes an upper peak hold circuit 76 and a lower peak (bottom) hold circuit 77 to which the push-pull signal PP is input, and an inverter 78 for inverting the phase of the output signal of the lower peak hold circuit 77.

The upper peak hold circuit 76 detects a positive polarity peak from the reference level in the push-pull signal PP and generates a signal corresponding to the detected level. The continuous wave train of signal PP is converted to a hold output signal UPH having a waveform having a high level for the duration of the wave train, as shown in FIG. The lower peak hold circuit 77 detects a negative polarity peak from the reference level in the push-pull signal PP and generates a signal corresponding to the detected level. The continuous wave train of signal PP is converted to a hold output signal LPH having a waveform having a low level for the duration of the wave train, as shown in FIG.

An inverted signal of the low peak hold output signal LPH is input to the OR gate 73 as a high level significant signal. Therefore, these signals UPH and LPH are equivalent to signals M1 and M2 shown in FIG.
4, the same clear input signal CLR can be supplied, and the same countermeasures against noise can be taken. Although the push-pull signal PP is used in the embodiments of FIGS. 5 and 7, the clear input signal CLR of the counter 74 may be generated using the read information signal RF (see FIG. 4) as follows. .

FIG. 9 shows the configuration of a spindle control system according to a third embodiment of the present invention, in which parts identical to those in FIGS. 4 and 5 are denoted by the same reference numerals. In FIG. 9, a differential amplifier 79 and a retriggerable monostable multivibrator (MMV) 7A are provided to obtain a clear input signal CLR (1) of the counter 74. The differential amplifier 79 has the read information signal RF as a non-inverting input, and a signal corresponding to a predetermined threshold value TH as an inverting input.
As a comparison means, a signal I corresponding to the level comparison result of both inputs
D is supplied to the MMV 7A. The MMV 7A is equivalent to the MMV 71 in FIG. 5, uses the signal ID from the differential amplifier 79 as a trigger input, and supplies its output signal to the counter 74 as a clear input signal CLR (1).

As shown in FIG. 10, the read information signal RF exhibits a continuous wave train of the same polarity by the preceding and succeeding ID recording units. This wave train exhibits a high level when it is larger than the threshold value and a low level otherwise when the differential amplifier 79 has a threshold value TH corresponding to a standard center level of the wave sequence. It is converted into a rectangular wave-shaped composite read address signal ID. Since the composite read address signal ID sequentially triggers the MMV 7A by the rising edge of each rectangular wave, a clear input that exhibits a high level from the beginning to the end of the rectangular wave train of the composite read address signal ID is output from the MMV 7A. Signal CLR
(1) is generated. The thus-obtained clear input signal CLR (1) is the same as that shown in FIG. 6, and the same countermeasures against noise are taken.

FIG. 11 shows a fourth embodiment as another mode for obtaining the clear input signal CLR using the read information signal RF. In FIG. 11, the same reference numerals are given to the same parts as those in FIGS. 4 and 5, while the configuration in which the clear input signal CLR (2) is generated by the upper peak hold circuit 7B is shown. The upper peak hold circuit 7B corresponds to the upper peak hold circuit 76 in FIG.
As shown in FIG. 10, the clear input is performed while a wave train is generated by the preceding and succeeding ID recording units of the read information signal RF (while the peaks come in rapid succession). The signal CLR (2) is set to a high level. The clear input signal CLR thus obtained
(2) is the same as that shown in FIG. 6, and the same countermeasures against noise are taken.

Although two MMVs are used in the embodiment shown in FIG. 5, a single MMV can generate the clear input signal CLR. Fig. 1 shows the configuration.
2, wherein the read address signals ID1 and ID2 are input to an exclusive OR gate 7C, and a composite read address signal ID as shown in FIG. 13 is generated from the gate. According to this, a signal equivalent to the clear input signal described above can be obtained from the output of the MMV 7A having the composite read address signal ID as a trigger input.

It should be noted that the ID area S
Although the case where the scanning point scans 0 has been described, other I
Even when the reading point scans the D area, the reproduction synchronization signal SYNC is obtained in the same manner except for the detailed operation. In each of the above embodiments, the preformatted ID information is obtained from the read signal, and the read error signal is used to generate the rotation error signal in the spindle control. Therefore, the disk is in an unrecorded or partially recorded state. In other words, even if marks of a sufficient data amount are not recorded in each sector of the land and the groove, the spindle control based on the read signal can always be performed in a good condition.

In the above embodiment, FIGS.
Although the spindle control is performed based on the data of the recording format as shown in the above, the present invention can be applied to other formats. That is, if the disc-shaped recording medium has an ID area in which the predetermined information indicating the recording position is preformatted and formed at predetermined time intervals at a predetermined time length, the ID is determined based on the read signal.
A detection signal (reproduction synchronization signal) is generated when it is detected that the time length of the region is equal to or longer than a predetermined length, and based on an error corresponding to the frequency and phase difference between the detection signal and the reference signal. The effect peculiar to the present invention can be obtained by controlling the spindle. Therefore a specific DVD
-Not limited to RAM.

In addition, although the above embodiment has been described in a limited manner, it can be appropriately modified within a range that can be designed by those skilled in the art.

[0032]

As described above in detail, the spindle control device according to the present invention can perform excellent spindle control on an unrecorded / partially recorded RAM type disk based on the read signal. .

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a conventional spindle control system that drives a CAV type disk to rotate.

FIG. 2 is a schematic diagram showing a recording format of a disk to be rotationally driven by a spindle control system according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a detailed form of an ID area in the recording format of FIG. 2;

FIG. 4 is a partial schematic block diagram showing a reading system of a disk player to which the spindle control system according to one embodiment of the present invention is applied;

FIG. 5 is a block diagram showing a detailed configuration of a spindle control system according to an embodiment of the present invention.

FIG. 6 is a view showing operation waveforms of respective parts in the spindle control system of FIG. 5;

FIG. 7 is a block diagram showing a detailed configuration of a spindle control system according to a second embodiment of the present invention.

FIG. 8 is a diagram showing operation waveforms of respective parts in the spindle control system of FIG. 7;

FIG. 9 is a block diagram showing a detailed configuration of a spindle control system according to a third embodiment of the present invention.

FIG. 10 is a view showing operation waveforms of respective parts in the spindle control system of FIGS. 9 and 11;

FIG. 11 is a block diagram showing a detailed configuration of a spindle control system according to a fourth embodiment of the present invention.

FIG. 12 is a block diagram showing a detailed configuration of a spindle control system according to a fifth embodiment of the present invention.

FIG. 13 is a view showing operation waveforms of respective parts in the spindle control system of FIG. 12;

[Explanation of symbols]

2 Spindle motor 21 Photodetector 31, 32, 33 Adder 34 Subtractor 40 Data demodulator 51, 52 Differential amplifier 60 Address demodulator 71, 72, 7A Retriggerable monostable multivibrator 73 OR gate 74 Counter 75 Decoder 75, 76B Upper peak Hold circuit 77 Lower peak hold circuit 78 Inverter 79 Differential amplifier 7C Exclusive OR gate 80 Frequency phase comparator 91 Crystal oscillator 92, 93 Divider

Claims (6)

[Claims] 1. A spindle control device for a disk player for obtaining a read signal from a disk having an ID area in which a recording position information signal is preformatted and formed at a predetermined time interval at a predetermined time interval. An optical reading unit that irradiates a light beam and receives return light passing through the recording surface of the disk; and detects that a time length of the ID area is equal to or longer than a predetermined length based on a light receiving output of the optical reading unit. ID detection means for generating a detection signal when the detection signal, reference signal generation means for generating a reference signal, error generation means for generating an error signal according to the frequency and phase difference between the detection signal and the reference signal, A drive unit for rotating the disk at a rotation speed according to the error signal. 2. The disk according to claim 1, wherein an information signal is recorded for each sector on a land track and a groove track, and the ID area is arranged at a sector boundary position between these tracks. Item 2. The spindle control device according to Item 1. 3. The ID area has an ID recording section in which the recording position information signal is recorded so as to be deviated in the radial direction of the disk by substantially a half track with respect to the land-shaped track and the groove-shaped track. 3. The spindle control device according to claim 2, wherein: 4. The ID recording section according to claim 3, wherein the ID recording section has a length substantially bisecting the ID area in a track direction and a width substantially equal to the land-shaped track or the groove-shaped track. Spindle control device. 5. The spindle control device according to claim 4, wherein the ID recording units are arranged in a staggered manner on a recording surface of the disk. 6. The spindle control device according to claim 1, wherein the reference signal has a frequency corresponding to a target rotation speed of the disk.