JP3276767B2 - Disc player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk player for reproducing an optical disk such as a compact disk (hereinafter, simply referred to as a CD).

[0002]

2. Description of the Related Art In recent years, such a disk player has been connected to a center unit for inputting various commands such as volume control and the like, and is configured to reproduce information recorded on the CD.
Players are widespread.

Now, such a CD player will be described with reference to FIG. FIG. 1 is a block diagram schematically showing a general CD player.

[0004] In the CD player of FIG.
A turntable 11 on which a CD inserted in the player is placed, a spindle motor 12 for rotating and driving the CD placed on the turntable 11, and a signal reading unit 13 for reading information and the like recorded on the CD A predetermined signal processing is performed on the information and the like read by the signal reading unit 13 to obtain a digital reproduction signal, and a read control signal component from the signal reading unit 13 and a drive control signal And a digital filter and a D / A for converting the digital reproduction signal into L-channel and R-channel analog reproduction signals while performing acoustic correction on the digital reproduction signal. The converter 15 removes unnecessary high-frequency components contained in the analog reproduced signal, and outputs the L channel and the R channel. A low-pass filter (hereinafter simply referred to as an LPF) 16 for supplying an audio signal of the channel to a main amplifier (not shown), and a feed motor for moving the signal reading section in the disk radial direction by a control signal from the signal processing section 14. A sled drive circuit 17 for generating a drive signal for driving a sled motor (hereinafter, referred to as a sled motor), a focus drive circuit 18 for generating a drive signal for driving a focus movable unit according to a control signal from the signal processing unit 14, A tracking drive circuit 19 for generating a drive signal for driving the tracking movable unit according to a control signal from the signal processing unit 14, and a spindle drive circuit for generating a drive signal for driving the spindle motor 12 according to a control signal from the signal processing unit 14 2
0 and a CPU 21 for controlling the entire CD player.

Although not shown, the signal reading section 13 irradiates a laser beam onto a disc surface of a CD via an optical component such as an objective lens, reflects the laser beam, and reflects information recorded on the disc from the laser beam. An optical pickup for reading is provided.

The optical pickup has a built-in focus movable portion and a tracking movable portion for adjusting the focus and tracking of the laser light to be irradiated. Further the signal on the disk read by the optical pickup, the focusing direction of the error amount signals necessary to control the focus moving unit (hereinafter, simply referred to as a focus error signal) and a tracking movable part and the thread movable portion Torraku tracking direction error quantity signals necessary to control (hereinafter,
A tracking error signal), a track presence / absence detection signal (hereinafter simply referred to as a mirror signal) for detecting the presence / absence of a track by detecting a mirror portion between tracks on the disk surface, a frame synchronization signal and a subcode And an RF amplifier that outputs an RF signal as a read signal.

The tracking movable section has a tracking coil for finely adjusting the objective lens within a movable limit range in the radial direction of the disk. When the tracking servo is ON, the track of the disk is controlled based on a tracking control signal. While performing a tracking operation for reading information recorded on the track while following the above, during a large-scale track jump such as a music selection operation, the tracking servo is turned off by stopping the tracking operation, and the tracking operation is stopped. supplies a drive signal to the coil, is adapted to move the front Symbol objective lens in a predetermined direction by supplying a drive signal also to the sled motor as required.

When the voltage is applied to the tracking coil, the objective lens moves within the movable limit range in the jump direction or the reverse direction, and supports the objective lens when no voltage is applied to the tracking coil. The lens support returns to a position near the center of the movable limit range by a spring return action. Further, when the objective lens is located near the center, the signal reading unit 13 can obtain a sufficient RF signal due to the optical characteristics. However, at the movable limit position, a sufficient RF signal is obtained due to the optical characteristics.
The signal may not be obtained.

The signal processing unit 14 includes the signal reading unit 13
It is an IC that processes various signals such as a reproduced signal, a focus error signal, a tracking error signal, a frame synchronization signal, and a subcode, which has a servo function and a digital signal processing function. The focus drive circuit 18, the tracking drive circuit 19, and the spindle drive circuit 20 are controlled. Note that the signal processing unit 14 is provided with a read detection signal (hereinafter simply referred to as GFS) for notifying whether or not a predetermined read signal such as the frame synchronization signal or the subcode is read.
(Referred to as a signal) to the CPU 21.

Next, the operation of the CD player for performing a large-scale track jump (2N track jumps) will be described with reference to FIGS. FIG. 3 is a flowchart showing the processing operation of the CPU 21 in a large-scale track jump. FIG. 4 is a timing chart showing the processing operation.

In FIG. 3, when performing a large-scale track jump of 2N tracks, the tracking servo and the thread servo are turned off (step S3).
1) An acceleration signal for accelerating the objective lens in the jump direction is supplied to the tracking coil of the tracking servo, and a sled acceleration signal for moving the sled motor in the jump direction is supplied (step S32).

It is determined whether or not the number of tracks jumped by the moving signal reading unit 13 has reached N (step S33). If the number of the jumped tracks has reached N, the supply of the acceleration signal to the tracking coil is stopped (Step S34), and a deceleration signal for decelerating the objective lens being accelerated is sent to the tracking coil (Step S34). Step S35). During the supply of the deceleration signal to the tracking coil, the cycle of detecting the mirror signal gradually increases because the acceleration of the objective lens is decelerating.

Next, it is determined whether or not the detection cycle of the mirror signal is equal to or longer than a predetermined cycle (step S36). If the detection period of the mirror signal is equal to or longer than a predetermined period, that is, if the speed of the objective lens is sufficiently low,
The supply of the deceleration signal to the tracking coil is stopped (step S37), the tracking servo is turned on to perform the tracking operation (step S38), and the sled acceleration signal to the sled motor after a predetermined time T1 (see FIG. 4) has elapsed. Stop the supply (Step S3
9) and turn on the thread servo (step S4)
0), the large-scale track jump is completed, and the flow shifts to a disk reproducing operation.

The operation of the CD player in the signal monitoring process during disc reproduction will be described with reference to FIG. FIG. 5 is a flowchart showing the processing operation of the CPU 21 in the signal monitoring processing.

The signal monitoring process is to periodically monitor the reading state of a frame synchronization signal, subcode, etc. of the signal reading unit 13 with respect to the optical pickup through the signal processing unit 14 during reproduction of a disk. is there.

In FIG. 5, it is determined whether or not the current focusing state is good (step S51). If the focusing state is good, a timer for a predetermined time, for example, 3 seconds is set (step S52), and the GFS signal obtained from the signal processing unit 14 is at a low level, that is, the reading state of the frame synchronization signal and the like by the optical pickup. Is determined to be defective (step S5).
3). If the GFS signal is low level, step S5
It is determined whether or not the timer set in 2 has timed out (step S54). If the timer has expired, the focus servo and the tracking servo are turned off, that is, the process shifts to a stop process for stopping the reading operation of the signal reading unit 13 (step S55), and the operation of the player is stopped.

If the GFS signal is not low in step S53, it is determined that the reading of the frame synchronization signal and the like by the optical pickup is good, and the normal reproduction process is performed (step S56). The process moves to S51.

If the focusing state is not good in step S51, a focus pull-in process for adjusting the objective lens and the like to improve the focusing state is performed (step S57), and the process proceeds to step S51.

If the timer has not expired in step S54, the flow shifts to step S53. In the signal monitoring process, the tracking state is also monitored in addition to the focusing state.

Therefore, according to the signal monitoring process, the reading state of the frame synchronization signal or the like is periodically monitored, and the optical pickup is driven within a predetermined time even if the focusing state is good. If the reading of the optical pickup is not successful, the reading operation of the signal reading unit 13 is stopped, so that various adverse effects due to erroneous reading of the optical pickup, for example, runaway of the spindle motor 12 and the sled motor can be prevented. .

[0021]

According to the above-mentioned conventional disk player, a large-scale track jump is performed on a disk having a defect portion such as a scratch on a track surface, and a deceleration signal is supplied to a tracking coil. When the light passes through the defect portion, the detection period of the mirror signal by the optical pickup becomes apparently longer.
Although the acceleration of the objective lens of the optical pickup is not sufficiently decelerated, the supply of the deceleration signal to the tracking coil is stopped, and the tracking servo is turned on.

Then, when the tracking servo is turned on, the tracking operation is started. However, since the acceleration of the objective lens is not sufficiently reduced, only the objective lens moves and is not located near the center position. The CPU 21 is stopped near the movable limit position, and the output of the RF signal is not sufficient due to the optical characteristics of the optical pickup near the movable limit position despite the good focusing and tracking conditions. The movement of the signal reading unit 13 is stopped by determining that the reading of the synchronization signal or the like is defective and turning off the thread servo in order to avoid runaway of the thread.

However, since the movement of the main body of the signal reading unit 13 is stopped, this state, that is, the state in which the objective lens is stabilized near the movable limit position, continues, and the CPU 21 performs the signal monitoring process. Has a problem that the reading operation of the signal reading unit 13 is stopped after a predetermined time (see step S55 in FIG. 5), and the operability is not good.

The present invention has been made in view of the above problems, and has as its object the operability of recovering from an unreadable state even when a large-scale track jump has passed a defect portion of a disc. An object of the present invention is to provide an excellent disc player.

[0025]

In order to achieve the above object, a disk player according to the present invention is a disk player for reading information recorded on a track of a disk by accessing an arbitrary track by a track jump. Reading means for reading information recorded on a track of the disc, and a reading means for moving the reading means in a radial direction of the disc, having a lens support portion for supporting a lens of the optical pickup by utilizing a spring return action. A moving means, a cycle detecting means for detecting an inter-track cycle, and a tracking servo turned off to supply a predetermined acceleration signal to the tracking driving means, and to provide the deceleration signal to the tracking driving means at a predetermined timing instead of the acceleration signal. When the inter-track cycle is equal to or longer than a predetermined cycle, the supply of the deceleration signal is stopped and Tsu and a track jump control means for performing a track jump by causing the King servo set to ON, the track jump control means, when and off Okashingu state and the tracking state after the end of the track jump are both good, the reading When a predetermined reading signal cannot be obtained from the means, the tracking servo is turned off for a predetermined time without turning off the focus servo.

[0026]

With this configuration, for example, when a large-scale track jump is performed on a disk having a defect portion and the objective lens stops near the movable limit position and a predetermined read signal cannot be obtained from the reading unit, By turning off the tracking servo for a predetermined time, the objective lens is returned to the center position by the elastic force of the lens supporting portion that supports the objective lens, so that a sufficient predetermined read signal is obtained by the reading means. In addition, the operability can be improved by solving a situation in which the reading operation of the reading unit is stopped unnecessarily as in the related art.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a disc player according to the present invention will be described with reference to the drawings. Although the description will be made using the CD player of FIG. 1 described in the related art, the description of the configuration and operation will be omitted because they are duplicated.

CD to which the disc player of the present invention is applied
As a feature of the player, the CPU 21 performs the following processing operation in parallel with the signal monitoring processing.
The reading means is a signal reading section 13, the moving means is a thread servo, and the control means and the cycle detecting means are a CP.
It corresponds to U21.

FIG. 2 is a flowchart showing the processing operation of the CPU 21 in the CD player to which the disc player of the present invention is applied.

For example, as described above, when a CD player makes a large-scale track jump on a disk having a defect portion and passes through the defect portion while a deceleration signal is being supplied to the tracking coil, the CD signal is output. Stop supply and set tracking servo to O
N. At this time, it is assumed that the objective lens of the optical pickup has stopped near the movable limit position because it has not been sufficiently decelerated, and the thread servo has been turned off due to a reading error such as a frame synchronization signal. .

At the time of the tracking operation when the tracking servo is ON, the CPU 21 outputs a low-level GFS signal such that a frame synchronization signal or the like cannot be read because the objective lens is stopped near the movable limit position. Then, while performing the signal monitoring process shown in FIG. 5, the process proceeds to the process described below.

In FIG. 2, it is determined whether or not the GFS signal is at a low level (step S11). If the GFS signal is at the low level, it is determined whether or not the time of the GFS error timer set in step S21 described later has expired (step S12). The GFS error timer is such that the tracking servo is turned off when the GFS signal is at a low level for the time set in step S21.

If the GFS error timer has expired, it is determined whether the tracking servo is off (step S13). It should be noted that whether or not the tracking servo is being turned off is determined by a flag set in step S15 described later.

If the tracking servo is not off, the tracking servo is turned off (step S14), a flag for notifying that the tracking servo is turned off is set (step S15), and the motor is stopped near the movable limit position. A timer for returning the middle objective lens to the vicinity of the center position is set (step S1).
6). The method of returning the objective lens to the vicinity of the center position within the movable range is to turn off the tracking servo,
By turning off the voltage applied to the tracking coil, the operation is performed by the spring return action of the lens supporting portion that supports the objective lens.

Next, the CD control function is stopped so as not to receive a command from the center unit (step S17), and the process proceeds to a main routine (not shown).

If the GFS signal is not low in step S11, the flow shifts to a main routine (not shown). If the GFS error timer has not timed out in step S12, the main routine (not shown) is executed. Move to routine.

If the tracking servo is OFF in step S13, it is determined whether the timer set in step S16 has expired (step S18). If the timer has expired, the tracking servo is turned on (step S19), a flag indicating that the tracking servo is being turned off is cleared (step S20), and the GF is cleared.
The S error timer is set to a predetermined time, for example, 200 msec (step S21), and the process shifts to a main routine (not shown).

If the timer has not expired in step S18, the flow shifts to a main routine (not shown).

Therefore, according to the CD player of the above embodiment, for example, a large-scale track jump is performed on a disk having a defect portion, and the optical pickup passes through the defect portion while a deceleration signal is being supplied to the tracking coil. In this case, turn off the tracking servo that performs the tracking operation after stopping the supply of the deceleration signal.
However, if a low-level GFS signal is detected by the signal monitoring processing at that time, the tracking servo is turned off for a predetermined time and the voltage applied to the tracking coil is turned off, so that the tracking servo is stopped near the movable limit position. The tracking servo was turned on after returning the middle objective lens to its center position using the spring return action of the lens support of the optical pickup.
The optical pickup can obtain a sufficient RF signal with the objective lens at the center position, and the operability is improved because the reading operation of the signal reading unit 13 is not stopped unnecessarily as in the related art. be able to.

In the above embodiment, the tracking servo is turned off and the objective lens is returned to the vicinity of the center position. However, in addition to the tracking servo, the spindle motor is turned off and then the objective lens is moved to the center position. If it is returned near the position, it is possible to cope with abnormal rotation of the disk.

[0041]

According to the disk player of the present invention configured as described above, for example, a large-scale track jump is performed on a disk having a defect portion, and the defect portion causes the inter-track period to be longer than a predetermined period. Even if this happens, when a predetermined read signal cannot be obtained from the reading means, the tracking servo is turned off for a predetermined time, so that a sufficient predetermined read signal can be obtained by the reading means, The operability can be improved by overcoming the conventional situation in which the reading operation of the reading unit is stopped unnecessarily.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of a general CD player to which a disc player of the present invention is applied.

FIG. 2 is a flowchart showing a processing operation in a CPU of a CD player to which the disc player of the present invention is applied.

FIG. 3 is a flowchart showing a processing operation of a CPU at the time of a large-scale track jump in the related art.

FIG. 4 is a timing chart showing a processing operation at the time of a large-scale track jump in the related art.

FIG. 5 is a diagram illustrating a CPU in signal monitoring processing according to the related art;
5 is a flowchart showing the processing operation of the first embodiment.

[Explanation of symbols]

 13 signal reading section (reading means) 21 CPU (control means, cycle detecting means)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 7/085 G11B 7/09 G11B 7/095

Claims (1)

(57) [Claims] 1. A disc player for reading information recorded on a track of a disc by accessing an arbitrary track by a track jump, and supporting a lens of an optical pickup by utilizing a spring return action. Reading means for reading information recorded on tracks of the disk, a moving means for moving the reading means in a radial direction of the disk, a cycle detecting means for detecting an inter-track cycle, and a tracking servo. OFF, a predetermined acceleration signal is supplied to the tracking driving means, and a deceleration signal is supplied to the tracking driving means at a predetermined timing instead of the acceleration signal. To stop track supply and turn on the tracking servo to perform a track jump. And a Kkujanpu control unit, the track jump control means, when and off Okashingu state and the tracking state after the end of the track jump are both good when no predetermined reading signal is obtained from said reading means The tracking servo is turned on for a predetermined time O without turning off the focus servo.
A disc player characterized by being an FF.