KR0157460B1 - High-speed searching apparatus - Google Patents

Abstract

The high-speed search method and apparatus thereof of the present invention include a frequency generator for detecting the rotational linear speed of the current track obtained from the spindle motor and a rotation speed of the spindle motor corresponding to the diameter of the disk, the recording medium. The controller controls the drive of the spindle motor by using the rotational linear speed of the current track and the rotational linear speed of the target track, and selectively outputs the spindle motor driving signal according to the conventional method and the spindle motor driving signal generated by the controller described above. A multiplexer is provided in the conventional optical pickup system to control the spindle motor to run at the rotational speed of the target track until the current track where the optical pickup is located matches the target track, and if the current track and the target track coincide with each other, Line speed control using comparison of bit clock and system clock synchronized with playback signal using phase locked loop The. Therefore, compared to the conventional method of executing the cruise speed control only when the optical pickup reaches the target track, the time required for the cruise speed control of the target track is reduced, thereby enabling high-speed search.

Description

High speed search method and device

1 is a block diagram showing a conventional compact disc player.

2 is a block diagram of a compact disc player with a fast search function according to an embodiment of the present invention.

3 is a conceptual diagram showing the relationship between the rotational speed of the spindle motor and the voltage applied to the spindle motor.

4 is a flow chart according to a preferred embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

31: system control unit 33: servo signal processing unit

34: ROM 35: D / A Converter

36: multiplexer 39: frequency generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed search method and apparatus thereof, and more particularly, to an elapsed time until an optical pickup approaches a target track and reads a signal on a disc driven by a constant linear velocity (CLV) method. The present invention relates to a high-speed search method and apparatus therefor for shortening.

In general, an optical pickup system that linearly moves an optical pickup in a radial direction of a disk driving in a constant velocity (CLV) method has a reproduction signal and a phase locked loop read out after reaching the target track position by the movement of the entire optical pickup. Phase Locked Loop circuit is used to generate a bit clock synchronized with the reproduction signal. Then, the signal recorded on the disk is accurately reproduced by controlling the rotation speed of the spindle motor which rotates the disk by using the system clock having the constant frequency and generated by the above-described bit clock and the system controller.

1 is a block diagram showing a conventional compact disc player.

The apparatus of FIG. 1 includes a spindle motor 7 for rotating the disk 8, an optical pickup 2 for reading out a signal from the disk 8, and a feeding for long-distance transfer of the optical pickup 2. A motor (4), an RF amplification unit (5) for amplifying and outputting an eight to fourteen modulation signal (EFM signal) read out through optical pickup, a tracking error and a focus error, and an RF A digital signal processor 6 which receives the output signal of the amplifier 5 and synchronizes and demodulates the signal, and receives a tracking error and a focus error from the first time of the RF amplifier 5. A servo signal processor (3) which receives the spindle motor control signal from the signal processor (6) and generates drive signals for the spindle motor (7), the feeding motor (4) and the optical pickup (2); The servo signal processor 3 receives the optical pickup transfer information from the servo signal processor 3 and outputs the optical pickup transfer control signal. And a system controller 1 for outputting a control signal for synchronizing and demodulating the EFM signal to the digital signal processor 6. The system controller 1 is connected to receive a subcode signal from the digital signal processor 6.

When the user selects a track other than the track currently being played in the playback mode, the operation of FIG. 1 apparatus is performed as follows.

The system controller 1 calculates a track aberration difference between the current track where the optical pickup 2 is located and the target track to be accessed and outputs it to the servo signal processor 3. The servo signal processing unit 3 drives the feeding motor 4 to transfer the optical pickup 2 to the target track. When the optical pickup 2 reaching the target track reads a signal from the target track and outputs the signal to the RF amplifier 5, the digital signal processor 6 uses the built-in phase locked loop (PLL) circuit to amplify the RF. A predetermined clock (hereinafter referred to as a bit clock) is generated in synchronization with the reproduction signal inputted through the section 5. When the bit clock is generated, the digital signal processor 6 compares the system clock output from the system controller 1 with the bit clock, and increases the rotational speed of the spindle motor 7 when the frequency of the bit clock is smaller than the system clock frequency. Outputs a control signal to the servo signal processor 3, and outputs a control signal to the servo signal processor 3 to reduce the rotational speed of the spindle motor 7 when the bit clock frequency is greater than the system clock frequency. .

When the rotation speed of the disk 8 is constant by the spindle motor control signal of the digital signal processing unit 3 for reducing the difference between the bit clock and the system clock, the digital signal processing unit 6 accurately corrects the signal recorded on the disk 8. Play it.

Such a conventional optical pickup system can record a signal on a disc-shaped disc and its disc-type disc by adjusting a difference between a bit clock and a system clock due to a reproduction signal read out through the optical pickup after reaching the target track. By matching the linear velocity at the time, it takes a lot of time to obtain the cruise velocity on the target track, which causes a problem that high-speed search is not achieved.

An object of the present invention for solving the above problems is to determine the rotational speed for each track of the disc-shaped disk according to the ship speed method in advance and then drive the spindle motor at the rotational speed corresponding to the target track to improve the ship speed of the target track. By providing a high-speed search method that can reduce the time required to accurately read the signal recorded on the disc-shaped disk.

Another object of the present invention is to provide a high-speed search method that implements the above method.

The object of the present invention is to provide a method for adjusting the rotational speed of a spindle motor to read a recording signal using optical pickup from a disk driven by the spindle motor in a constant speed method. Storing a target rotational speed of the spindle motor, setting a target track of a disk to be accessed by the optical pickup, driving the spindle motor at a target rotational speed corresponding to the target track, and optical pickup Determining whether the current track and the target track are identical, detecting the current rotational speed of the spindle motor and comparing it with the target rotational speed, until the current rotational speed and the target rotational speed match or the current track. Adjusting the driving voltage of the spindle motor until the target track coincides with the target track; When tracks are matched is obtained by the high-speed search method spindle motor comprising the step of driving the spindle motor at a rotational speed determined by the synchronous detection of the signal to be read out through an optical pick-up.

In addition, another object of the present invention is to provide an optical pickup apparatus for adjusting a rotational speed of a spindle motor for reading a recording signal from a disc driven by a constant speed (CLV) method, wherein the target of the spindle motor corresponding to the diameter of the disc is provided. Means for storing the rotational speed, means for detecting the current rotational speed of the spindle motor, digital signal processing means for receiving the signal read out from the disk and generating the spindle motor control signal, and tracking error output from the optical pickup. A servo signal processing means for generating an output number of tracks in which an optical pickup has moved and generating a first drive signal for driving a linear speed of the spindle motor in a target track by receiving the spindle motor control signal; and a spindle by the detection means. Spindle motor on target track by inputting current rotation speed of motor and target rotational speed read from storage means A system control means for generating a second drive signal for cruise line speed control and controlling the entire system; and receiving the first drive signal and the second drive signal, and if the current track where the optical pickup is located does not match the target track, And a multiplexer for outputting two drive signals to the spindle motor and outputting the first drive signal to the spindle motor when the current track matches the target track.

Hereinafter, with reference to the accompanying drawings an embodiment of the high-speed search method and apparatus of the present invention will be described in detail.

2 is a block diagram showing a compact disc player with a fast search function according to an embodiment of the present invention.

The apparatus of FIG. 2 generates a disk 38 for storing an EFM signal, a spindle motor 37 for rotating the disk 38, and a pulse signal FG corresponding to the rotational speed of the spindle motor 37. An RF pickup connected to the frequency generator 39, an optical pickup 32 for reading an EFM signal from the disk 38, and a signal output terminal of the optical pickup 32, and amplifying and outputting an EFM signal, a tracking error and a focus error. The digital signal processor 41 outputs a demodulated EFM signal, a spindle motor control signal (SPE), and a sub code (SUBCODE) by receiving the EFM signal from the RF unit 40 and the RF amplifier 40. And a tracking error and a focus error from the RF amplifier 40 to output driving signals of the feeding motor 42 and the optical pickup 32 and the number of tracks SENS moved by the optical pickup 32. The spindle motor drive signal SPVI, which is an analog voltage value, is generated by receiving the spindle motor control signal SPE from the digital signal processor 41. A servo signal processor 33, a ROM 34 storing voltage values for generating a rotational speed of the spindle motor 37 corresponding to the tracks of the disk 38, a system clock counter and a pulse signal (FG) counter And the number of tracks (SENS) at which the voltage value output from the ROM 34, the pulse signal FG from the frequency generator 39, and the optical pickup 38 from the servo signal processor 33 move. And digital / analog conversion of the spindle motor drive voltage (SPV2) output from the system controller (31) and the system controller (31) for outputting a selection control signal for adjusting the rotational speed of the spindle motor (37). The input signal from the D / A converter 35 and the servo signal processing unit 33 and the output signal from the D / A converter 35 are transferred to the spindle motor 37 in accordance with the control signal of the system controller 31. And an analog multiplexer (MUX) 36 for selective output. The above-described system controller 31 outputs the system generated from the built-in clock generator (not shown) to the digital signal processor 41 and outputs the sub code detected by the digital signal processor 41. It is connected to receive input.

3 is a conceptual diagram showing the relationship between the rotational speed of the spindle motor and the voltage (V) applied to the spindle motor. The rotational speed of the spindle motor is set in RPM (Revolution Per Minute), and the relationship thereof is displayed.

In general, the voltage applied to the spindle motor and the rotational speed of the spindle motor have a linear relationship as shown in FIG. 3, and the relation between the diameter of the compact disc rotating at the ship speed of 1.25m / sec and the rotational speed of the spindle motor is as follows. Table 1 is as follows.

FIG. 4 is a flow chart according to another preferred embodiment of the present invention, which describes the operation of the compact disc player until the target track to be accessed matches the current track where the optical pickup is located when transferring the optical pickup. It is a flowchart for doing so.

Referring to FIG. 4, the operation of the compact disc player of FIG. 2 will be described.

When the user enters a search mode for searching for a predetermined target track by inputting a command, the system controller 31 outputs a control signal for transferring the optical pickup 32 to the position of the target track to the servo signal processor 33. The voltage value corresponding to the rotational speed of the track is read from the ROM 34 and output to the D / A converter 35 (step 1). At the same time, the system controller 31 generates a selection signal SEL to control the multiplexer 36 to output a signal input to the predetermined input terminal S2. (Step 2) Then, the system controller 31 The built-in pulse signal counter and system clock counter not shown in the figure are initialized (step 3). The servo signal processor 33 drives the feeding motor 42 and the optical pickup 32 to transfer the optical pickup 32 to the target track. When the multiplexer 36 applies an analog voltage value output through the D / A converter 35 to the spindle motor 37, the spindle motor 37 rotates at a rotational speed corresponding to the input voltage value. Rotate The frequency generator 39 connected to the spindle motor 37 generates a pulse signal FG having a frequency corresponding to the rotational speed of the spindle motor 37 (step 4). When the servo signal processor 33 generates and outputs the number of tracks SENS of the optical pickup 32 using the tracking error output from the RF amplifier 40, the system controller 31 is transferred to the target track. It is determined whether the current track detected by the optical pickup 32 is matched (step 5), and the pulse signal FG and the system clock are counted using the pulse signal counter and the system clock counter. If the counted system clock does not reach a certain number of times, the system controller 31 determines whether the current track and the target track match (step 5) and determines whether the counted system clock has reached a certain number of times. Repeat step (step 6).

Thus, if it is determined by the number of moving packs SENS of the optical pickup 32 that the current track and the target track of the optical pickup 32 match, the system control unit 31 outputs the selection control signal SEL to the servo. The voltage value SPVI output from the signal processor 33 is controlled to be applied to the spindle motor 37 through the multiplexer 36 (step 7).

If the current track and the target track do not match and the counted system clock reaches a certain number of times, the system controller 31 calculates the rotational speed of the current spindle motor 37 using the counted system clock and the pulse signal FG. (Step 8), the system clock counter and the pulse signal counter are initialized again (step 9).

After performing step 9, the system controller 31 compares the calculated rotational speed of the spindle motor 37 with the rotational speed of the spindle motor 37 corresponding to the target track (step 10). If there is a match, the step of determining whether the current track and the target track match (step 5) is repeated. On the other hand, if the calculated rotational speed and the target rotational speed do not match, the system controller 31 determines whether the calculated rotational speed is larger than the target rotational speed (step 11). The system controller 31 reduces the drive voltage SPV2 of the spindle motor 37 and outputs it to the D / A converter 35 when the calculated rotation speed is larger than the target rotation speed (step 12), and vice versa. The drive voltage SPV2 of the motor 37 is increased and output (step 13). After performing steps 12 and 13, the system control unit 31 repeats from step 5.

Thus, when the current track and the target track coincide with the spindle motor 37 rotating at a speed suitable for the target track, the system control unit 31 generates the selection control signal SEL to perform the digital signal processing unit in the same manner as in the related art. The drive voltage SPV1 generated by the servo signal processing unit 33 is controlled to be outputted to the spindle motor 37 through the multiplexer 36 by the spindle motor control signal SPE obtained at 41. The servo signal processor 33 adjusts the optical pickup 32 to accurately travel on the target track by using a tracking error and a focus error input from the RF amplifier 40. The digital signal processing section 41 reproduces the synchronized EFM signal using the bit clock and the system clock obtained by the phase locked loop in the same manner as in the related art. The subcode output from the digital signal processor 41 is processed by the system controller 31 and used by the user to easily use the player.

The high-speed search method and apparatus of the present invention as described above are a ROM for storing the rotational speed of the spindle motor corresponding to the diameter of the disk and the frequency generator for detecting the rotational linear speed of the current track obtained from the spindle motor (ROM), a control unit for controlling the drive of the spindle motor by using the rotational linear speed of the current track and the rotational linear speed of the target track, and the spindle motor driving signal according to the conventional method and the spindle motor driving signal generated by the controller described above. In addition to the conventional optical pickup system, an optional multiplexer is provided to control the spindle motor to run at the rotational speed of the target track until the current track where the optical pickup is located matches the target track. As in the prior art, a phase locked loop is used to compare a bit clock and a system clock synchronized with a reproduction signal. Control ship speed. Therefore, compared to the conventional method of executing the cruise speed control only when the optical pickup reaches the target track, the time required for the cruise speed control of the target track is reduced, thereby enabling high-speed search.

Claims (5)

A device for adjusting the rotational speed of a spindle motor for reading a recording signal by using optical pickup from a disk driven by a CLV method by a spindle motor, the target rotational speed of the spindle motor corresponding to the diameter of the disk. Means for storing; Means for detecting a current rotational speed of the spindle motor; Digital signal processing means for receiving a signal read from the disk and generating a spindle motor control signal; Servo signal processing that receives the tracking error output from the optical pickup and generates and outputs the number of tracks that the optical pickup has moved, and receives the spindle motor control signal and generates the first drive signal for driving the linear speed of the spindle motor in the target track. Means; System control means for receiving the current rotational speed of the spindle motor by the detection means and the target rotational speed read out from the storage means to generate a second drive signal for driving the linear speed of the spindle motor in the target track and to control the entire system; ; When the current track where the optical pickup is located does not match the target track by receiving the first drive signal and the second drive signal, the second drive signal is output to the spindle motor, and the first drive signal when the current track matches the target track. High speed search apparatus comprising a multiplexer for outputting the spindle motor. The optical control apparatus of claim 1, wherein the system control means receives a current rotational speed and a target rotational speed of the spindle motor and compares the magnitude thereof with each other to adjust the driving voltage of the spindle motor. A selection signal generator for controlling the output signal of the multiplexer by determining whether the target track and the current track correspond to the number of tracks moved, and a voltage value corresponding to the target rotation speed at the time of search. And a selection unit for outputting the second driving signal and selecting and outputting the voltage value generated by the driving voltage adjusting unit as the second driving signal. The method of claim 2, wherein the driving voltage adjusting unit outputs the driving voltage is reduced when the current rotational speed of the spindle motor is greater than the target rotational speed, and increases the output voltage if the current rotational speed of the spindle motor is less than the target rotational speed. High speed search device. A method of adjusting the rotational speed of a spindle motor to read a recording signal using optical pickup from a disk driven by a constant speed method by a spindle motor, the method comprising: storing a target rotational speed of a spindle motor corresponding to tracks of the disk. Making a step; Setting a target track of a disc to be accessed by the optical pickup; Driving the spindle motor at a target rotational speed corresponding to the target track; Determining whether the current track where the optical pickup is located and the target track match; Detecting a current rotational speed of the spindle motor and comparing it with a target rotational speed; Adjusting the driving voltage of the spindle motor until the current rotational speed and the target rotational speed coincide or until the current track and the target track coincide; And driving the spindle motor at a rotational speed determined by the synchronous detection of a signal read through the optical pickup when the current track and the target track coincide in the determining step. The method of claim 4, wherein the step of adjusting the driving voltage is to reduce the spindle motor driving voltage when the current rotation speed of the spindle motor is greater than the target rotation speed, and to increase the spindle motor driving voltage when the current rotation speed is smaller than the target rotation speed. High speed search method characterized in that.