CN1290097C - Optical read-write head control method when optical disc drive performs long-distance tracking - Google Patents

Abstract

The present invention is a method for controlling an optical head when an optical disc drive performs long-distance tracking. When the optical disc drive performs long-distance tracking, a signal is applied to the optical head to provide a bias voltage to overcome the inertia of the optical head, so that the optical head will not oscillate during the long-distance tracking process, thereby increasing the probability of successful locking operation of the optical disc drive.

Description

Optical read-write head control method when optical disc drive performs long-distance tracking

technical field

The invention relates to a control method of an optical disc drive, and in particular to a control method of an optical read-write head when the optical disc drive performs long-distance tracking.

Background technique

The optical disc is a storage medium capable of fast random access (Random Access). In order to meet the requirements, the optical disc drive must be able to use the Seeking Servo to accurately send the Sledge to the target position at the fastest speed at any time, and then the Tracking Servo will take over the optical drive. Track On operation of the read/write head.

For example, please refer to FIG. 1 , which shows a schematic diagram of a conventional optical read-write head performing rail-lock operation. Generally speaking, when the optical disk drive is performing long-distance tracking (Long Seek), the tracking servo system controls the trolley 26 to the target position, and then the tracking servo system performs the locking of the optical read-write head 24. And there is a movable range 27 on the pulley 26 to provide the optical read-write head 24 as the fine-tuning range of the optical read-write head 24 when the track is locked, track (Following), or short jump (short Seek). Generally speaking, when the optical read-write head is not under any control, the elastic element 25 will control the optical read-write head 24 to stay at the central position of the movable range 27 . In FIG. 1 , when the trolley 26 moves to the target position, the tracking servo system can control the optical head to lock the target track 23 on the optical disc 22 .

Please refer to FIG. 2 , which is a schematic diagram of signals applied to the carriage motor when the optical disc drive performs long-distance tracking. In order to speed up the access operation of the optical disk drive, the optical disk drive will apply a large force to drive the slider when performing long-distance tracking. When the slider is about to reach the target position, it will reduce the force applied to the slider to reduce the speed of the slider. For example, a pulley motor signal (Feed Motor Output, FMO) is used in the optical disc drive to apply a pulley motor to drive the pulley. In order to achieve fast access to the data on the optical disc, when the optical disc drive starts to perform long-distance tracking (t0-t1), the signal applied by the carriage motor must provide a large force to quickly drive the carriage; when the carriage is about to reach the target position (t1 ), the pulley motor application signal must gradually reduce the applied force. When the trolley reaches the target position, the optical read-write head can smoothly perform the rail locking operation because the speed of the trolley decreases.

Generally speaking, when the tackle motor drives the tackle to perform long-distance track-seeking in the initial stage, it is necessary to provide a larger applied force to the tackle. Since the optical read-write head is only connected with the trolley by an elastic element, when the trolley moves rapidly, the optical read-write head will oscillate back and forth within a movable range. When the trolley arrives at the target position, because the optical read-write head is still in an unstable state, the rail locking operation of the optical read-write head often fails.

In order to successfully realize the track-locking operation of the optical read-write head, generally speaking, the conventional optical read-write head will provide a central error output signal (Central Error Output, CEO) to confirm the position of the optical read-write head in the movable range. The center error output signal is the position signal of the optical head within the movable range. When the center error output signal is at the zero crossing point, it means that the optical read-write head is in the center of the movable range. Therefore, the actual position of the optical read-write head in the movable range can be determined according to the output value of the center error of the optical read-write head.

In the control chip of a conventional optical disc drive, an optical head application signal is provided, and the optical head application signal performs closed-loop control according to the center error output signal, that is, the output signal after the center servo control (Center Servo Control). Therefore, the signal applied by the optical pick-up head can maintain the optical pick-up head at the center position of the movable range during the operation of the long track.

However, in order to reduce the manufacturing cost of the optical pick-up head, a certain optical pick-up head will not have a center error output signal. Please refer to FIG. 3 , when the trolley moves in the direction of the arrow A of 26 , due to inertial factors, the optical read-write head 24 will deviate in the opposite direction of the direction A and generate oscillation. Because the control chip of the optical disc drive cannot perform closed-loop control according to the center error output signal. Therefore, as a result of the oscillation of the optical head in the movable range during the long-distance tracking operation, the track locking operation of the optical head will fail.

Contents of the invention

The object of the present invention is to provide a method for controlling the optical pickup when the optical disk drive performs long-distance tracking, so that the optical pickup does not exhibit unstable oscillation when the optical disk drive does not have central servo control.

The present invention proposes a method for controlling an optical read-write head when an optical disc drive performs long-distance tracking, including the following steps: determining the moving direction of the trolley; Make the optical read-write head move to the moving direction.

The present invention proposes a method for controlling an optical read-write head when an optical disc drive performs long-distance tracking, including the following steps: driving the trolley according to a signal applied by the trolley motor; to the optical read-write head, so that the pulley and the optical read-write head move in the same universal direction of motion.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings related to the present invention. However, the drawings are provided for reference and description, and are not intended to limit the present invention.

Description of drawings

What Fig. 1 represents is the schematic diagram that the conventional optical read-write head carries out the track lock operation;

FIG. 2 is a schematic diagram of the force curve applied by the carriage motor when the optical disc drive performs long-distance tracking;

Fig. 3 represents the relative position schematic diagram between the optical read-write head and the tackle when the tackle motor drives the tackle; and

FIG. 4 shows the control method of the optical read-write head when the optical disc drive performs long-distance tracking according to the present invention.

Description of figure number

22 CD-ROM 23 Target track

24 Optical read-write head 25 Elastic element

26 Pulley 27 Movable range

Detailed ways

In order to prevent the optical read-write head from oscillating back and forth within the movable range during the long-distance tracking process, and cause the optical read-write head to fail to lock the track. The invention provides a method for controlling an optical read-write head when an optical disc drive performs long-distance tracking. The invention is applied to an optical read-write head that does not have an output center error output signal.

When the optical disc drive drives the trolley to perform long-distance tracking operation, the control chip of the optical disc drive must first confirm the moving direction of the trolley, and use the signal applied by the optical read-write head on the control chip to provide a bias voltage to overcome the inertia of the optical read-write head And make the optical read-write head not to oscillate. That is to say, when controlling the pulley motor to apply force to the pulley, the optical read-write head is also used to apply a signal to apply force to the optical read-write head at the same time, so that the pulley and the optical read-write head have the same acceleration. Therefore, the optical read-write head can be greatly reduced. Unstable oscillation of the write head.

Please refer to FIG. 4 , which shows the control method of the optical head when long-distance tracking is performed in the present invention.

Step S1: When the optical disc drive performs long-distance tracking, determine the moving direction of the carriage according to the signal applied by the carriage motor; and

Step S2: Simultaneously drive the carriage and the optical read-write head with the signal applied by the carriage motor and the optical read-write head respectively.

According to an embodiment of the present invention, since the weights of the tackle and the optical read-write head are different, the size between the signal applied by the carriage motor and the signal applied by the optical read-write head can be determined according to the weight ratio. Therefore, the weight of the tackle and the optical read-write head Both heads can obtain the same acceleration, so that the optical read-write head does not oscillate.

Due to inertial factors, conventional optical read/write heads will deflect in the opposite direction of the moving direction and oscillate. However, the present invention provides an optical pick-up head to apply a signal to provide a reverse inertial bias voltage, so that the position of the optical pick-up head will be fixed at a specific position in the movable range during the long-distance tracking process of the optical disc drive. Unstable oscillations will occur. Therefore, when the optical disc drive enters the track-locking operation after finishing the long-distance track-seeking operation, since the optical read-write head has been stabilized, the track-locking operation can be realized smoothly.

Therefore, the advantage of the present invention proposes a method for controlling the optical pick-up head when the optical disc drive performs long-distance tracking. The inertia prevents the optical read-write head from oscillating during the long-distance track-seeking process, so the probability of successful track-locking operation of the optical disc drive can be improved.

In summary, although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications without departing from the spirit and scope of the present invention. movements and modifications, the scope of the invention is therefore that defined by the appended claims.

Claims (3)

1. An optical read-write head control method when an optical disc drive performs long-distance tracking, comprising the following steps: determining a direction of motion of a tackle; and When the carriage moves, an applied force in the same direction as the movement is provided to an optical pick-up head, so that the optical pick-up head moves toward the movement direction. 2. An optical read-write head control method when an optical disc drive performs long-distance tracking, comprising the following steps: actuating a trolley in response to a signal applied by a trolley motor; and When the slider moves, an optical pickup head is provided to apply a signal to apply a force to an optical pickup head at the same time, so that the slider and the optical pickup head move in the same moving direction. 3. The method as claimed in claim 2, wherein there is a fixed ratio between the signal applied by the carriage motor and the signal applied by the optical pick-up head.

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