JP2005141878A - Optical pickup feed device in optical pickup device, optical pickup feeding method and program thereof, and information recording medium thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup feeding device, in which stepped-out sound caused by the fact that an optical pickup is pressed against a stopper in the optical disk device is reduced and power consumption at the time of movement of the optical pickup is reduced, and to provide an optical pickup feeding method and a program thereof, and an information recording medium. <P>SOLUTION: In the optical pickup feed device for reading information from the optical disk in the optical disk device, the device is provided with a drive voltage control means (a drive current supply means 8, a drive waveform generating means 9, a control part 10, a gain (waveform amplitude) switching means 11, a fundamental waveform generating means 12, and a nonvolatile memory 13) for controlling the drive voltage of a stepping motor 4 moving the optical pickup 1, the drive voltage control means controls so that drive voltage of the stepping motor is dropped during movement at uniform speed or movement at reduced speed, after the optical pickup starts movement, and finishes acceleration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical pickup feeding device, an optical pickup feeding method, a program thereof, and a readable information recording medium on which the program is recorded in an optical disc apparatus used for a CD-ROM drive or the like.

  In the optical disc apparatus, for the purpose of cost reduction, an optical disc apparatus that does not include an optical pickup position detection means using a photo interrupter or a push switch has been commercialized.

  In the optical disk device, when the position information of the optical pickup is required without detecting (or when the position information cannot be detected), such as when the power is turned on or when the optical disk is inserted, There is. In this case, positional information of the optical pickup is obtained by sufficiently moving the optical pickup in the inner or outer peripheral direction and stopping the movement by pressing against the innermost or outermost stopper.

  For example, in the case of the optical disc apparatus that uses a stepping motor for the optical pickup feeding device, the stepping motor rotates by a predetermined step angle with respect to one pulse of the driving waveform, so that open loop control is easy. Displacement detection means such as an encoder is not required.

  However, when the power is turned on or when the disc is inserted, the optical pickup feeding mechanism using the stepping motor does not have the displacement detection means, and therefore cannot detect whether the optical pickup is pressed against the stopper.

Therefore, in Patent Document 1, as one of the solution means, the optical pickup is sent by sending the optical pickup for a predetermined time (number of steps) so as to move to the position where it is pressed against the stopper regardless of the position of the optical pickup. A method for detecting the position of the optical pickup by moving the optical pickup to a predetermined position after the operation is disclosed is disclosed.
Japanese Patent Laid-Open No. 11-306701

  However, in the movement of the optical pickup for detecting the position of the optical pickup, the optical pickup causes a step-out in a state where it is pressed against the inner or outer stopper, and the step-out sound generated at this time is noisy. There is.

  In view of the above-described problems, the present invention provides a control for lowering the driving voltage of the stepping motor within a range in which the stepping motor does not step out after the optical pickup finishes accelerating and reaches a constant speed during movement of the optical pickup. Means are provided.

  The present invention provides an optical disk apparatus in which step-out noise generated when the optical pickup is pressed against a stopper is reduced by providing control means for lowering the driving voltage of the stepping motor, and power consumption during movement of the optical pickup is reduced. It is an object of the present invention to provide an optical pickup feeding device, an optical pickup feeding method, a program thereof, and a readable information recording medium on which the program is recorded.

  The invention according to claim 1 comprises a stepping motor for moving an optical pickup for reading information from an optical disc, and a drive voltage control means for controlling the drive voltage of the stepping motor, and the optical pickup moves. The drive voltage control means is an optical pickup feeding device that controls to switch the drive voltage of the stepping motor at the time of constant speed movement or decelerated movement after starting acceleration and ending acceleration. The drive voltage control means comprises, for example, a drive current supply means, a drive waveform generation means, a control unit, a gain (waveform amplitude) switching means, a basic waveform generation means, and a nonvolatile memory in the embodiments described below. Is done.

  According to a second aspect of the present invention, the drive voltage control means controls the drive voltage of the stepping motor to be lowered within a range in which the stepping motor does not step out at a moving speed after the optical pickup finishes accelerating. An optical pickup feeding device according to claim 1 is provided.

  According to a third aspect of the present invention, the drive voltage control means has a drive voltage value lower than the drive voltage value of the stepping motor during the acceleration movement of the optical pickup, in a range where the stepping motor does not step out. Investigating in advance, recording the drive voltage value in a nonvolatile memory, and referring to the drive voltage value recorded in the nonvolatile memory when switching the drive voltage, the drive voltage of the stepping motor is the same as the drive voltage value The optical pickup feeding device according to claim 1 or 2 is controlled so as to be

  The drive voltage control means for controlling the drive voltage of the stepping motor for moving the optical pickup for reading information from the optical disk is the first aspect of the invention, wherein the optical pickup starts moving and finishes accelerating. The optical pickup feeding method includes a step of controlling to switch the driving voltage of the stepping motor during constant speed movement or decelerated movement.

  According to a fifth aspect of the invention, the drive voltage control means controls the drive voltage of the stepping motor to be lowered within a range in which the stepping motor does not step out at a moving speed after the optical pickup finishes accelerating. 5. The optical pickup feeding method according to claim 4, further comprising a step.

  According to a sixth aspect of the present invention, the drive voltage control means has a drive voltage value lower than the drive voltage value of the stepping motor during the acceleration movement of the optical pickup in a range where the stepping motor does not step out. The step of investigating in advance, the step of recording the drive voltage value in the nonvolatile memory by the drive voltage control means, and the drive voltage value recorded in the nonvolatile memory by the drive voltage control means when switching the drive voltage The optical pickup feeding method according to claim 4, further comprising: a step of referring to the step of controlling the stepping motor so that the driving voltage of the stepping motor is equal to the driving voltage value. It is characterized by that.

  The invention described in claim 7 is a readable information recording medium in which a program for causing a computer to execute the method described in claims 4 to 6 is recorded.

  The invention described in claim 8 is a program for causing a computer to execute the method described in claims 4 to 6.

  According to the present invention, in the pickup feeding device in the optical disc apparatus, by providing the control means for lowering the driving voltage of the stepping motor, the step-out sound generated when the pickup is pressed against the stopper is reduced, and the pickup movement Power consumption can be reduced.

  One embodiment of an optical pickup feeding device in an optical disk apparatus according to the present invention is provided with a driving voltage control means for controlling a driving voltage of a stepping motor that moves an optical pickup that reads information from an optical disk, and the optical pickup moves. The drive voltage control means controls the drive voltage of the stepping motor to be lowered during constant speed movement or deceleration movement after starting acceleration and ending acceleration. As a result, it is possible to reduce the step-out sound generated when the optical pickup is pressed against the stopper, and to reduce the power consumption when the pickup is moved.

  A schematic configuration and operation of an optical disk drive of this embodiment applied to the present invention will be described with reference to the accompanying drawings. FIG. 6 is a schematic block diagram of the optical disk drive of the present embodiment. FIG. 6 is a schematic block diagram of a recording / reproducing optical disc drive, but it may be a reproducing drive in which a recording compensation circuit is omitted.

  The optical disk drive of this embodiment shown in FIG. 6 includes a disk motor 21, an optical pickup sending means 22, an optical pickup 23, a recording compensation means 24, an RF signal processing means 25, a modulation / demodulation means 26, a signal input section 27, a signal output. The unit 28, the servo 29, the CPU 30, the ROM 31, and the RAM 32 are included.

  As shown in FIG. 6, the signal input unit 27 and the signal output unit 28 are connected to an audio circuit, an image compression / expansion circuit, or an interface for connection with a computer depending on the purpose of use of the signal.

  The recording compensation unit 24 includes a laser modulation by a recording signal, and the RF signal processing unit 25 includes a circuit such as a waveform shaping of a read signal. The servo 29 detects a tracking error signal, an error component of the focus error signal, and the like from the read signal and feeds back to the optical pickup 23 and the disk motor 21 for control. Although not shown in the figure, the servo 29 is mainly composed of a focus servo, a tracking servo, an optical pickup feed servo, and the like.

  For the optical pickup feeding means 22, a feed screw method, a rack and pinion method, a linear motor method, and the like are known. The CPU 30 controls the entire apparatus according to programs stored in the ROM 31 and RAM 32. The RAM 31 temporarily stores data necessary for control.

  Normally, a tracking error signal is used for the optical pickup feed servo of the servo 29 shown in FIG. In a normal reproduction or recording operation, when the tracking error signal becomes a certain value or more, an electric current is passed to an optical pickup feed motor not shown in FIG. Rotate. The entire optical pickup 23 moves in the radial direction of the disk 20 by the rotation of the motor.

  The current to the optical pickup feed motor is controlled by the CPU 30 so as to stop flowing when the tracking error signal becomes smaller than a certain value, and stops the rotation of the optical pickup feed motor.

  On the other hand, at the time of access, under the control of the CPU 30, the optical pickup feed servo loop is not used, but a current is passed through the optical pickup feed motor, and the optical pickup 23 is moved from the inner circumference to the outer circumference of the disk 20 or in the opposite direction. It is moved with.

  By counting the number of steps of the optical pickup feeding motor during the movement of the optical pickup 23, the optical pickup 23 can access up to the target destination. When the optical pickup 23 reaches near the destination, the CPU 30 turns on the optical pickup feed servo loop to operate the servo and reproduce the signal.

  Then, the CPU 30 calculates the deviation of the optical pickup 23 from the target moving position, and again performs feed by counting the number of tracks, returns feed, or track jump, and accesses the optical pickup 23 to the target moving position.

  Next, detailed contents of the optical pickup feeding apparatus of the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing a driving voltage waveform of the optical pickup of the present embodiment. FIG. 2 is a block diagram showing the configuration of the optical pickup feeding apparatus according to this embodiment. FIG. 3 is a diagram showing the change over time of the moving speed of the optical pickup of the present embodiment. FIG. 4 is a diagram showing drive voltage waveforms of the present embodiment and the conventional optical pickup.

  As shown in FIG. 2, the optical pickup feeding apparatus of this embodiment includes an optical pickup 1, a guide shaft 2, a stopper 3, a stepping motor 4, a tooth 5, a screw shaft 6, a spindle motor 7, and a drive current supply means 8. , Drive waveform generation means 9, control section 10, gain (waveform amplitude) switching means 11, basic waveform generation means 12, and nonvolatile memory 13.

  The pickup 1 for reading information from the optical disk shown in FIG. 2 is driven by a stepping motor 4 through a tooth 5 attached to the pickup 1 and a screw shaft 6 meshing with the tooth 5 in the radial direction of the disk. Move along the guide shaft 2. The pickup 1 also has a stopper 3 that prevents the pickup 1 from moving more than necessary.

  When the pickup 1 is moved for the purpose of seeking or the like, the drive waveform generation means 9 that has received the information of the movement distance (number of steps) from the control unit 10 outputs a drive voltage waveform according to the profile stored in the nonvolatile memory 13. The drive current supply means 8 is configured to be able to perform PWM drive, and supplies drive current to the stepping motor 4 based on the drive waveform. As a result, the stepping motor 4 is driven.

  By the way, in the optical disk apparatus having the above-described configuration that does not have a means for detecting a position without reading information on the optical disk, the position of the optical pickup 1 is not used when the power is turned on or the disk is inserted. In order to obtain information, the control unit 4 issues a command to send the stepping motor 4 by the number of steps sufficiently pressed against the stopper 3 regardless of the position of the optical pickup 1.

  In the present embodiment, the drive waveform generating means 9 drives the optical pickup 1 as shown in FIG. 4 after the acceleration section in the speed profile of the optical pickup 1 illustrated in FIG. Change the amplitude of the voltage waveform to a smaller value. In the case of two-phase excitation driving, the driving voltage waveform is a waveform in which the phases of the A phase and the B phase are shifted by a quarter cycle as shown in FIG.

  When the optical pickup 1 is moved for the purpose of position detection described above, the basic waveform generating means 12 shown in FIG. 2 performs a pulse rate (speed) according to the profile recorded in the nonvolatile memory 13 when the optical pickup 1 is accelerated or decelerated. ). The basic waveform generator 12 maintains a pulse rate when the optical pickup 1 moves at a constant speed, and generates a drive waveform having a constant amplitude.

  Further, the gain switching means 11 switches a predetermined gain (amplitude of the drive waveform) recorded in the nonvolatile memory 13 after entering the constant velocity section in the movement of the optical pickup 1 shown in FIG. As the gain value, a value at which the stepping motor 4 does not step out at a pulse rate at a constant speed, which is a gain switching interval, is selected in advance and recorded in a nonvolatile memory.

  Next, the contents of the optical pickup feeding process in the optical pickup feeding apparatus of this embodiment will be described mainly with reference to FIG. FIG. 5 is a flowchart for explaining the contents of the optical pickup feeding process in the optical pickup feeding apparatus of this embodiment. This process is a process executed by the CPU (control unit 10: FIG. 2) in accordance with a program stored in the ROM 31 (nonvolatile memory 13: FIG. 2) shown in FIG.

  This process starts after the power is turned on or the disk is inserted. As shown in FIG. 5, first, in step S1, the CPU assigns 0 to the loop counter variable m. Next, in step S2, it is determined whether or not the loop counter variable m matches n + 1. That is, the variable m is between 0 and n, which is the acceleration interval of the optical pickup. If the CPU determines that the variable m matches n + 1, the CPU determines that the acceleration section of the optical pickup has ended, and proceeds to the process of step S5.

  Next, in step 3, the CPU issues a command to the basic waveform generating means 12 shown in FIG. 2 so as to output a pulse having a period t (m). As a result, the basic waveform generating means 12 drives the stepping motor 4 with the drive voltage waveform as shown in FIG. 4 during the acceleration period of the optical pickup via the drive current supply means 8. As the value of m in the acceleration interval increases, the cycle t (m) is decreased.

  In step 4, the CPU increments the loop counter m by 1.

  In step 5, when this process is reached, the acceleration section ends and becomes a constant speed section, so the CPU gives a command to the gain switching means 11 shown in FIG. 2 to lower the gain to a predetermined value.

  In step 6, the CPU determines whether or not the period t (m) matches P + 1. That is, the variable m is a constant velocity interval between n + 1 and p. If it is determined that the variable m is equal to p + 1, the CPU determines that the constant velocity section of the optical pickup is completed, and the process proceeds to step 9.

  In step 7, the CPU issues a command to the basic waveform generating means 12 to output a pulse having a period t (m). As a result, the basic waveform generating means 12 has a constant period t (m) through the drive current supply means 8 during the constant velocity section.

  In step 8, the CPU increments the loop counter m by 1.

  When this process is reached, the constant velocity section ends and becomes a deceleration section, so the CPU gives a command to the gain switching means 11 to return the gain to the original value. Note that when performing control that does not return the gain to the original value, the process of step 9 may be passed through.

  In step 10, the CPU determines whether or not the variable m matches r + 1. That is, when the variable m is between p + 1 and r, it is a deceleration zone. If it is determined that the variable m coincides with r + 1, the CPU determines that the deceleration section has ended, and the process ends. If there is no problem in this process, the pickup 1 comes into contact with the stopper 3 before the end of the process, and the initial position is determined.

  In step 11, the CPU issues a command to the basic waveform generating means 12 to output a pulse having a period t (m). As a result, the basic waveform generating means 12 drives the stepping motor 4 with the drive voltage waveform as shown in FIG. 4 during the deceleration zone via the drive current supply means 8. As the value of m in the deceleration zone increases, the period t (m) is increased.

  In step 12, the CPU increments the loop counter m by 1.

  As described above, in this embodiment, the optical pickup feeding apparatus to which the present invention is applied has been described. However, in accordance with the spirit of the present invention, the apparatus configuration, control conditions, etc. of the optical pickup feeding apparatus to which the present invention is applied can be changed as appropriate. it can.

It is a figure which shows the drive voltage waveform of the optical pick-up of a present Example. It is a block diagram of the configuration of the optical pickup feeding device of the present embodiment. It is a figure which shows the time change of the moving speed of the optical pick-up of a present Example. It is a figure which shows the drive voltage waveform of a present Example and the conventional optical pick-up. It is a figure which shows the flowchart for demonstrating the content of the optical pick-up sending process in the optical pick-up sending apparatus of a present Example. 1 is a block diagram of a schematic configuration of an optical disk drive of an embodiment to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up 2 Guide shaft 3 Stopper 4 Stepping motor 5 Teeth 6 Screw shaft 7 Spindle motor 8 Drive current supply means 9 Drive waveform generation means 10 Control part 11 Gain (waveform amplitude) switching means 12 Basic waveform generation means 13 Non-volatile memory 20 Disc 21 Disc Motor 22 Optical Pickup Feed Unit 23 Optical Pickup 24 Recording Compensation Unit 25 RF Signal Processing Unit 26 Modulation Demodulation Unit 27 Signal Input Unit 28 Signal Output Unit 29 Servo 30 CPU
31 ROM
32 RAM

Claims (8)

A stepping motor that moves an optical pickup for reading information from the optical disc;
Drive voltage control means for controlling the drive voltage of the stepping motor,
The optical pickup feeding device, wherein the drive voltage control means controls to switch the drive voltage of the stepping motor at the time of constant speed movement or deceleration movement after the optical pickup starts moving and finishes accelerating. .   2. The drive voltage control means controls to lower the drive voltage of the stepping motor within a range in which the stepping motor does not step out at a moving speed after the optical pickup finishes accelerating. The optical pickup feeding device as described.   The drive voltage control means investigates in advance a drive voltage value lower than the drive voltage value of the stepping motor in the range where the stepping motor does not step out and during the accelerated movement of the optical pickup, and the drive voltage A value is recorded in a nonvolatile memory, and when the drive voltage is switched, the drive voltage value recorded in the nonvolatile memory is referred to and controlled so that the drive voltage of the stepping motor becomes the same as the drive voltage value. The optical pickup feeder according to claim 1 or 2.   The drive voltage control means for controlling the drive voltage of the stepping motor that moves the optical pickup for reading information from the optical disc is the constant speed movement or the decelerated movement after the optical pickup starts moving and finishes accelerating. An optical pickup feeding method comprising the step of controlling to switch the driving voltage of the stepping motor.   The drive voltage control means includes a step of controlling the drive voltage of the stepping motor to be lowered within a range where the stepping motor does not step out at a moving speed after the optical pickup finishes accelerating. The optical pickup feeding method according to claim 4. The drive voltage control means is a range in which the stepping motor does not step out, and in advance investigates a drive voltage value lower than the drive voltage value of the stepping motor during acceleration movement of the optical pickup;
The drive voltage control means recording the drive voltage value in a nonvolatile memory;
The drive voltage control means referring to the drive voltage value recorded in a nonvolatile memory when the drive voltage is switched;
6. The optical pickup feeding method according to claim 4, wherein the driving voltage control means includes a step of controlling the driving voltage of the stepping motor to be the same as the driving voltage value.   A readable information recording medium on which a program for causing a computer to execute the method according to claim 4 is recorded.   A program for causing a computer to execute the method according to claim 4.

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