JP4220487B2 - Optical disc apparatus, optical disc apparatus control method, and control program - Google Patents

Description

  The present invention relates to an optical disc apparatus for recording / reproducing an optical optical disc, and more particularly, to an optical disc apparatus improved in disc rotation control, a control method thereof, and a control program.

  In an optical disc apparatus that records and reproduces an optical disc such as a CD or a DVD, the recording surface is irradiated with a laser beam via an optical pickup including an objective lens, and the reflected light is converted into an electric signal. Reading the recorded signal. The optical pickup is provided so that it can move in the focus direction (up and down) and tracking direction (left and right) according to the current flowing through the coil of the actuator, but keeps the focus on the recording surface during playback. Need to be.

  For this reason, in such an optical disk apparatus, the reflected light from the recording surface received by the objective lens and dispersed by the beam splitter is guided to a photodiode called a detector, and this detector generates a current that flows according to the amount of reflected light. Accordingly, focus servo for finely adjusting the position of the objective lens is performed. For example, using the fact that the main spot does not draw a perfect circle if the focus is not achieved, based on the difference in the light quantity of a predetermined pair of sections among the light quantities divided into four parts with the center of the main spot as a reference Thus, this is detected as a focus error signal, and control is performed so that the current flows through the coil at a voltage corresponding to this so that the optical pickup moves in a direction to cancel the error.

  Such an operation in the focus servo is generally called a focus pull-in operation, but the focus pull-in operation can be performed only within a range where the focus error signal can be detected, that is, within a small range before and after the focus position. . For this reason, in such a disk device, the objective lens is moved up and down, referred to as focus search, and the focus servo is turned on when a focus error signal is obtained.

  By the way, in the optical disk apparatus as described above, the information extracted by the reflected light includes a synchronization signal for keeping the rotation of the disk constant. Based on this synchronization signal, the motor is accelerated. The disk rotation is controlled by decelerating.

  For example, when the rotation of the disk is stopped, a process as shown in FIG. 7 is performed. That is, when the disk is rotating, rotational braking is started by applying a voltage for rotating the motor in the reverse direction (step 701). In the meantime, the state of rotation such as whether the rotation is stable or in focus is monitored by the synchronization signal (steps 702 and 703). If the rotation is not stable and the focus is not achieved, a predetermined time is waited (step 704), and braking is stopped (step 706). The braking is also stopped (step 706) when the rotation has decreased to a predetermined state (step 705). After braking is stopped, a predetermined inertial rotation period is provided and the rotation stop is completed.

  The relationship between the disc rotation control and the focus pull-in operation is as follows. That is, the disk rotation is slightly accelerated in advance when the focus is pulled in. If the pull-in is not successful, the disk rotation may be further accelerated before the next pull-in. After the focus pull-in is completed, the rotation servo operates to stabilize the rotation within a predetermined range and take out information.

As described above, as a technique for accelerating at the time of focus pull-in, there is one described in Patent Document 1.
Japanese Patent Publication No. 7-34287

  However, in the optical disc apparatus as described above, information cannot be appropriately extracted from the reflected light when the focus pull-in is not completed. In addition, when the rotation of the disk is slow and the rotation servo does not work, a synchronization signal cannot be obtained. Therefore, it is impossible to detect how fast the rotation is, and it is not possible to properly determine when to stop the rotation braking. For this reason, if normal rotational braking is applied in such a case, there is a possibility of over-braking and the disk rotating in the reverse direction, or taking out the disk from the apparatus while rotating without sufficient braking, and damaging the disk.

  In order to cope with this, it is conceivable that the brake is rotated by inertia and gradually brought into the stop without performing active braking, but it takes time to stop. In particular, when the disk is scratched or dirty, or when the apparatus is exposed to vibration, the focus cannot be pulled in easily, and even if it is desired to stop the rotation, it cannot be stopped immediately.

  The present invention has been proposed to solve the above-described problems of the prior art, and its purpose is to prevent overbraking and insufficient braking, and to reliably rotate the disc in a short time. It is an object of the present invention to provide an optical disc apparatus that can be stopped, a control method thereof, and a control program.

In order to solve the above problems, the invention of claim 1 is directed to a motor driving unit that drives a motor that rotates a disk, and a rotation control unit that controls acceleration and braking of the disk by controlling the motor driving unit. A pickup driving unit that drives an optical pickup that outputs a signal based on the reflected light of the disc, a signal detection unit that detects a signal from the optical pickup, and a light including a focus pull-in operation by controlling the pickup driving unit In an optical disc apparatus having a pickup control unit that controls the operation of the pickup, in the focus pull-in operation, an acceleration time integration unit that integrates the time for accelerating the rotation of the disc, and before the rotation state where the signal of the disc can be detected When stopping the disc, the amount of braking is determined by the acceleration time integration unit. A braking amount calculation unit for calculating, based on the accumulated time Te, the focus pull-in operation, and a coasting time integrator for integrating the rotation time of the disk due to inertia after the acceleration, the braking amount calculation unit, the The inertia time accumulated by the inertia time accumulation unit is discounted from the braking time when the disk is stopped .

According to a third aspect of the present invention, there is provided a method for controlling an optical disc apparatus in which a computer or an electronic circuit controls acceleration and braking of a motor for rotating a disc and controls an operation of an optical pickup including a focus pull-in operation. circuit, in the focus pull-in operation, integrates the time to accelerate the rotation of the disk, based on the integrated time, and calculates the braking amount at the time of stopping the disk before a signal detectable rotational state of the disc In the focus pull-in operation, the rotation time of the disk due to inertia after acceleration is integrated, and the integrated inertia time is discounted from the braking time when the disk is stopped .

According to a fifth aspect of the present invention, there is provided a control program for an optical disc apparatus that causes a computer to control acceleration and braking of a motor that rotates a disc and to control the operation of an optical pickup including a focus pull-in operation. In operation, the time for accelerating the rotation of the disk is accumulated, and based on the accumulated time, the braking amount when the disk is stopped before the rotation state where the disk signal can be detected is calculated, and the accumulated inertia The time is discounted from the braking time when the disk is stopped .

In the above aspect , even when the synchronization signal cannot be obtained due to the case where the focus cannot be retracted, etc., when stopping the disk, the braking is performed based on the acceleration time accumulated during the focus retract operation. Overbraking and insufficient braking are prevented, and the disc can be stopped reliably in a short time.

Further, since the rotation time due to inertia is discounted, braking based on accurate braking time can be performed.

According to a second aspect of the present invention, in the optical disk player of the first aspect , the optical disk player has an inertia time storage unit that stores a predetermined inertia time applied in the focus pull-in operation. In the focus pull-in operation, the rotation of the disk due to the inertia after acceleration is performed. It has an inertia frequency measurement unit that counts the number of inertias generated, and the time accumulated by the inertia time integration unit is obtained by multiplying the inertia time by the inertia frequency. In addition, this invention can also be grasped | ascertained as the control method of an optical disk apparatus, and the program for control of an optical disk apparatus as described in Claim 4 and 6.
In above-described embodiment, if the pre-inertia time can be assumed, in the coasting time, by utilizing a simple calculation that obtained by multiplying the inertia of times, it can be calculated braking amount.

  According to the present invention as described above, an optical disc device capable of preventing over-braking and insufficient braking and stopping the disc rotation in a short time, a control method therefor, and a control program are provided. be able to.

  Hereinafter, an embodiment (this embodiment) to which the present invention is applied will be specifically described with reference to the drawings. In this embodiment, the spindle motor and the optical pickup are controlled by operating the microcomputer and its peripheral circuits in accordance with a program for realizing the function of each unit described below. Various implementation modes can be changed. Therefore, in the following description, a virtual circuit block that realizes each function of the present invention is used. Further, the signal processing method, the program for realizing the signal processing method by a computer, and the recording medium on which the signal processing method is recorded according to the present embodiment are also one aspect of the present invention.

[Constitution]
In the present embodiment, as shown in FIG. 1, the disk D mounted on the turntable 1 is rotated by the spindle motor 2, and the reflected laser beam is detected while the optical pickup 3 is scanned by the feed mechanism. This is an optical disk device that records and reproduces information on the recording surface of the disk D. Although not shown, the optical pickup 3 includes a laser diode, an objective lens, an actuator, a detector, a cylindrical lens, a collimator lens, a beam splitter, and the like. Since these members and a feed mechanism for scanning the members can apply any known technique, description thereof is omitted.

  Further, the present embodiment includes a pickup driving unit 4, an amplifier unit 5, a motor driving unit 6, a signal processing unit 7, and the like. The pickup driving unit 4 is a driver that drives the actuator of the optical pickup 3 with a driving voltage. The amplifier unit 5 is means for amplifying a signal read by the optical pickup 3 and inputting the amplified signal to the signal processing unit 7. The motor driving unit 6 is a driver that drives the spindle motor 2. The pickup driving unit 4 and the motor driving unit 6 are controlled by signals from the signal processing unit 7.

  The signal processing unit 7 includes a signal detection unit 71, a pickup control unit 72, a rotation control unit 73, a time measurement unit 74, a number measurement unit 75, a setting storage unit 76, an integration unit 77, a braking amount calculation unit 78, and the like. Yes. The signal detection unit 71 is means for detecting various signals from the optical pickup 3. The pickup control unit 72 is a means for controlling a focus pull-in operation, various servos, and the like based on a signal from the signal detection unit 71 and the like. The rotation control unit 73 is a means for controlling acceleration, braking, rotation servo, and the like based on a signal from the signal detection unit 71, a braking amount from the braking amount calculation unit 78, and the like.

  In the present embodiment, “acceleration” and “braking” refer to applying a predetermined voltage to the spindle motor 2 for a predetermined time, and “acceleration” is intended to promote forward rotation of the spindle motor 2. “Brake” refers to applying a voltage for rotating the spindle motor 2 rotating in the forward direction in the reverse direction. In addition, “acceleration time” and “braking time” refer to the time during which the voltage is applied, and “inertia time” refers to the time during which the disc is rotating due to inertia after acceleration.

  The time measuring unit 74 is means for measuring the acceleration time and the inertia time using a built-in timer. The number measuring unit 75 is a means for counting the number of accelerations or the number of times that inertia rotation has occurred (the number of inertias). The setting storage unit 76 is a means for storing various settings for control. In particular, in the present embodiment, a predetermined acceleration time, inertia time, upper limit of focus trial time, calculation result, and the like are included. The accumulating unit 77 calculates a cumulative value of acceleration time or inertia time based on the time measured by the time measuring unit 74, the number of times measured by the number measuring unit 75, and information stored in the setting storage unit 76. It is. The braking amount calculating unit 78 is a unit that calculates the braking amount of the spindle motor 2 based on the integrated value integrated by the integrating unit 77.

  The signal processing unit 7 processes a data signal detected from the optical disk by the optical pickup 3 and processes a reproduction signal to be output as audio data, image data, etc., in order to process a signal conversion unit, a signal amplification unit, and an error correction unit. However, since any known technique can be applied to these, description thereof is omitted.

[Action]
The operation of the present embodiment having the above configuration will be described with reference to the flowcharts of FIGS.
[Control by accumulating acceleration time]
First, control based on acceleration time integration will be described with reference to FIGS. That is, acceleration and acceleration time measurement processing are performed according to instructions from the rotation control unit 73 (step 201). As shown in FIG. 3, the motor driving unit 6 applies (accelerates) the voltage for driving the spindle motor 2 and then stops supplying the voltage (step 301), and the voltage application time (acceleration time) is set to the time. The measurement is performed by the measurement unit 74 measuring (step 302) and the integration unit 77 integrating the acceleration time (step 303). As described above, when the voltage supply is stopped after the voltage is applied to the spindle motor 2, the disk D on the turntable 1 rotates by inertia after the rotation starts.

  In response to an instruction from the pickup control unit 72, the pickup driving unit 4 causes the optical pickup 3 to perform a focus pull-in operation on the disk D that rotates with inertia (step 202). When the focus cannot be retracted (step 203), the braking amount calculation unit 78 calculates a braking amount (braking time) based on the accumulated acceleration time (step 204).

  Based on the calculated braking amount, a braking process is performed in accordance with an instruction from the rotation control unit 73 (step 205). As shown in FIG. 4, the motor drive unit 6 applies (brakes) a voltage that reversely drives the spindle motor 2 (step 401), and when the braking time has elapsed (step 402), the voltage supply is stopped. (Step 403).

  On the other hand, when the focus can be pulled in (step 203), the rotation control unit 73 instructs the rotation for reading the disc information, and the rotation for that starts (step 206). Then, after CLV (Constant Linear Velocity) servo (step 207), disk information is read.

[Control by counting acceleration times]
First, control by accumulating acceleration time will be described with reference to FIGS. That is, in accordance with an instruction from the rotation control unit 73, acceleration and acceleration count processing are performed (step 501). As shown in FIG. 6, the voltage applied by the motor driving unit 6 to drive the spindle motor 2 is applied (accelerated) for a predetermined time set in the setting storage unit 76, and then the voltage supply is stopped (step 601). This is done by counting the number of times the voltage is applied (the number of accelerations) by the number measuring unit 75 (step 602). As described above, when the voltage supply is stopped after the voltage is applied to the spindle motor 2, the disk D on the turntable 1 rotates by inertia after the rotation starts.

  In response to an instruction from the pickup control unit 72, the pickup driving unit 4 causes the optical pickup 3 to perform a focus pull-in operation on the disk D rotating with inertia (step 502). If focus pull-in cannot be performed (step 503), if the focus trial time set in the setting storage unit 76 has not been exceeded from the start of the focus pull-in operation (step 504), acceleration and acceleration count processing are performed again (step 504). Step 501).

  When the focus trial time is exceeded (step 504), the accumulating unit 77 calculates the accumulated acceleration time by accumulating the count number to the preset acceleration time, and the braking amount calculating unit 78 A braking amount (braking time) is calculated based on the accumulated acceleration time (step 505).

  Based on the calculated braking amount, a braking process is performed in accordance with an instruction from the rotation control unit 73 (step 506). As in FIG. 4, the motor drive unit 6 applies (brakes) a voltage that reversely drives the spindle motor 2 (step 401), and when the braking time has elapsed (step 402), the voltage supply is stopped (step 402). Step 403).

  On the other hand, when the focus can be pulled in (step 503), the disk information is read after starting the disk rotation (step 507), after the CLV servo (step 508), as described above.

[Control with inertia time taken into account]
Furthermore, the control which considered the inertia time is demonstrated. That is, when performing the acceleration processing (steps 301 and 601), the time measuring unit 74 measures the inertial rotation time after the voltage application is stopped, and the accumulating unit 77 accumulates the time. When the braking amount is calculated by the braking amount calculation unit 78 (steps 204 and 505), the inertia time integration is subtracted from the acceleration time integration value, and this is used as the braking amount. The integrated value of the inertia time can also be obtained by multiplying the inertia time preset in the setting storage unit 76 by the number of accelerations (or the number of inertia rotations) counted by the number measuring unit 75.

[effect]
According to the present embodiment as described above, even if the focus cannot be pulled in by the optical pickup 3 and a synchronization signal or the like cannot be obtained, the spindle motor is based on the accumulated acceleration time during the focus pull-in operation. 2 can be braked, so that overbraking and insufficient braking are prevented. Therefore, the disk is not rotated backward and the disk is not damaged during removal. In addition, since the disk D rotating by inertia is not left to be stopped, but actively braked, the disk can be reliably stopped in a short time.

  In addition, when the braking amount is calculated based on the multiplication result of the count number and the set value, the arithmetic processing can be simplified and the speed can be increased. Furthermore, when the braking amount is calculated by subtracting the rotation time due to inertia, overbraking can be prevented more reliably.

[Other Embodiments]
The present invention is not limited to the above embodiment. For example, the braking amount calculation by the braking amount calculation unit may be performed by directly using the integration result by the integration unit as the braking time, or may be finely adjusted by applying an appropriate coefficient (parameter). The time measured by the time measuring unit and the integrated value by the integrating unit may also be finely adjusted by a coefficient. When performing the above-mentioned focus pull-in operation, the upper limit of the number of accelerations is determined in advance, an integrated value determined by multiplying the upper limit value and the acceleration time is set in advance, and when the count number reaches the upper limit value, The value may be a braking amount. This further simplifies the calculation of the braking amount.

  Various hardware configuration modes are possible, such as realization by so-called chips and their peripheral circuits that realize the functions exemplified above, or realization by a system LSI that integrates multiple functions. It is not limited to the embodiment. Furthermore, the optical disc player that is the subject of the present invention can be applied to all types of optical recording media. It may be a reproduction-only one or a recordable / reproducible one. Therefore, the applied voltage, acceleration time, inertia time, acceleration count, inertia count, focus trial time, integrated value, and braking amount can be freely set according to the type of disc that can be used.

1 is a functional block diagram showing an embodiment of an optical disc device of the present invention. It is a flowchart which shows the control processing by integration | accumulation of the acceleration time in embodiment of FIG. It is a flowchart which shows the acceleration and acceleration time measurement process of FIG. It is a flowchart which shows the braking process of FIG. It is explanatory drawing which shows the control processing by the count of the frequency | count of acceleration in embodiment of FIG. It is a flowchart which shows the acceleration of FIG. 5, and an acceleration time measurement process. It is a flowchart which shows the disk rotation stop process in the conventional optical disk apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Turntable 2 ... Spindle motor 3 ... Optical pick-up 4 ... Pick-up drive part 5 ... Amplifier part 6 ... Motor drive part 7 ... Signal processing part 71 ... Signal detection part 72 ... Pick-up control part 73 ... Rotation control part 74 ... Time measurement Unit 75 ... Counting unit 76 ... Setting storage unit 77 ... Integration unit 78 ... Braking amount calculation unit D ... Disc

Claims (6)

A motor driving unit that drives a motor that rotates a disk, a rotation control unit that controls acceleration and braking of the disk by controlling the motor driving unit, and an optical pickup that outputs a signal based on the reflected light of the disk is driven. In an optical disc apparatus having a pickup drive unit, a signal detection unit that detects a signal from an optical pickup, and a pickup control unit that controls the operation of the optical pickup including a focus pull-in operation by controlling the pickup drive unit ,
In the focus pull-in operation, an acceleration time integration unit that integrates the time for accelerating the rotation of the disk,
A braking amount calculating unit that calculates the braking amount based on the time accumulated by the acceleration time integrating unit when the disk is stopped before the rotation state in which the disk signal can be detected;
In the focus pull-in operation, having an inertia time integration unit that integrates the disc rotation time due to inertia after acceleration,
The optical disk apparatus characterized in that the braking amount calculation unit discounts the inertia time accumulated by the inertia time accumulation unit from the braking time when the disk is stopped . An inertia time storage unit for storing a predetermined inertia time applied in the focus pull-in operation;
In the focus pull-in operation, it has a inertia number measurement unit that counts the number of inertias that caused the rotation of the disk due to inertia after acceleration,
The inertia time is integrated by time integrating unit, the inertia time, the optical disk apparatus according to claim 1, characterized in that it is obtained by multiplying the inertia times. In a control method of an optical disc apparatus in which a computer or an electronic circuit controls acceleration and braking of a motor that rotates a disc and controls the operation of an optical pickup including a focus pull-in operation.
The computer or electronic circuit is
In the focus pull-in operation, integrate the time to accelerate the disk rotation,
Based on the accumulated time, calculate the amount of braking when stopping the disk before it reaches the rotation state where the signal of the disk can be detected ,
In the focus pull-in operation, the disc rotation time due to inertia after acceleration is integrated,
A method of controlling an optical disc apparatus, wherein the accumulated inertia time is discounted from a braking time when the disc is stopped . Memorize the predetermined inertial time applied in the focus pull-in operation,
  In the focus pull-in operation, count the number of inertias that caused the disc rotation due to inertia after acceleration,
  4. The method of controlling an optical disc apparatus according to claim 3, wherein the accumulated time is obtained by multiplying the inertia time by the inertia count. In a control program for an optical disc apparatus that causes a computer to control acceleration and braking of a motor that rotates a disc and to control the operation of an optical pickup including a focus pull-in operation,
In the computer,
In the focus pull-in operation, integrate the time to accelerate the disk rotation,
Based on the accumulated time, let's calculate the amount of braking when stopping the disk before entering the rotation state where the signal of the disk can be detected ,
A program for controlling an optical disk device, wherein the accumulated inertia time is discounted from a braking time when the disk is stopped . Store the predetermined inertial time applied in the focus pull-in operation,
  In the focus pull-in operation, the number of inertias that caused the disc to rotate due to inertia after acceleration is counted.
  6. The program for controlling an optical disc apparatus according to claim 5, wherein the accumulated time is obtained by multiplying the inertia time by the inertia count.

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