JP4495683B2 - Rotation control device, rotation control method, and information processing device - Google Patents

Description

  The present invention relates to a technical field such as a rotation control device that controls the rotational drive of a disk-shaped recording medium, a rotation control method thereof, and an information processing device.

  A disk-shaped storage medium (hereinafter also referred to as a disk) is used as a recording medium for audio signals and video signals to record information by forming pit rows provided on the surface as tracks. Therefore, when reproducing the recording medium, such a pit row is detected by an optical pickup and converted into an electric signal to reproduce an audio signal or a video signal recorded on the disc.

  At the time of reproducing recorded information, the disk is rotated at a high speed by, for example, a spindle motor, and the rotation speed of the spindle motor is accurately controlled by a rotation speed control circuit or the like. In addition, in order to accurately detect the pit row, control servo processing for the focus servo, tracking servo, and the like is performed on the optical pickup.

  In order to control the rotation of the disk, it is known to drive the disk at a constant linear velocity by using a constant linear velocity (CLV) method. Such disk rotational driving with a constant linear velocity provides advantages such as no change in error rate because information can be read from the disk at a constant rate.

  However, the center of the disk is different for each disk, and the deviation of the center is called the eccentricity. For example, as shown in FIG. 5A, when the disc 5 is deviated from the original center C1 of the hole 51 by an eccentric amount E, when reproducing such a disc 5, the shaft of the spindle motor is used. Coincides with the center C2 of the hole 51. When the disk 5 is rotated in this state, the distance from the center C2 to the arbitrary track 52 becomes the minimum L2 at the point A and the maximum L1 at the point B.

When the tracking servo is applied, the pickup lens (not shown) always operates to trace on the track 52. When the rotational speed of the disk 5 is DA, the speed VA at which the point A passes through the lens can be expressed by (Expression 1).
VA = 2π * L2 / (60 / DA) (Formula 1)

Next, as shown in FIG. 5B, after the pickup reads the point A, the disk 5 rotates 180 °, and when the point B is read, the pickup is shifted in the outer circumferential direction by X = L1-L2. Must be. At this time, if the rotational speed of the disk 5 is DB, the speed VB at which the point B passes through the lens can be expressed by (Expression 2).
VB = 2π * (L2 + X) / (60 / DB) (Formula 2)

  However, since the CLV control is based on the condition that the linear velocity is constant, the control must always be performed so that VA = VB. In other words, 2π * L2 / (60 / DA) = 2π * (L2 + X) / (60 / DB) to DB = DA * (L2 + 2E) / L2, when point A passes through the lens and point B is the lens. It is known that the number of rotations of the disk 5 must be changed when passing through.

As shown in Patent Document 1, a signal recording / reproducing apparatus that performs mechanical adjustment so as to cancel the above-described eccentricity is known. In this signal recording / reproducing apparatus, a configuration is adopted in which the eccentric amount and the eccentric direction of a track are detected, and the disc is aligned based on the detected eccentric amount and eccentric direction.
Japanese Patent Laid-Open No. 10-11888

  However, since the signal recording / reproducing apparatus described above performs mechanical adjustment so as to cancel out the eccentricity, it is necessary to provide an alignment mechanism in the configuration, and there is a problem that the cost of parts increases. In addition, since the alignment mechanism is provided, there is a problem that the thickness direction of the apparatus increases and it is difficult to reduce the size of the apparatus. The problem to be solved by the present invention includes the above-described problem as an example.

  Therefore, in view of the above-described problems, an object of the present invention is to provide a rotation control device, a rotation control method, and an information processing device that can cancel the eccentricity of a disk-shaped recording medium with a simple configuration.

In order to solve the above-mentioned problems, the rotation control device according to claim 1, wherein the rotation control device according to the present invention rotationally drives a disk-shaped recording medium, and a drive signal for making the rotational driving of the disk-shaped recording medium constant at a linear velocity. And a drive control means for controlling the drive of the rotation drive means, wherein an eccentricity amount detection means for detecting an eccentricity amount of the disc-shaped recording medium and the eccentricity amount detection means detect A legitimacy judging means for judging the legitimacy of the eccentricity, and a gain of the rotation driving means for rotating the disc-shaped recording medium at a constant linear velocity by canceling the eccentricity detected by the eccentricity detecting means. possess a gain specifying unit for specifying, and a gain adjusting means for outputting to said rotation driving means to adjust the drive signal of the drive control means on the basis of the gain the gain specifying means has specified a Serial gain specifying means, in response to said determination that there is no legitimate justification decision means, and specifying a fixed gain predetermined and the gain.

In order to solve the above-mentioned problems, the rotation control method according to claim 3, wherein the rotation driving means for rotating the disk-shaped recording medium is a drive signal for rotating the disk-shaped recording medium at a constant linear velocity. In the rotation control method controlled by the above, the eccentricity detection process for detecting the eccentricity of the disc-shaped recording medium, the correctness determination process for determining the correctness of the detected eccentricity, and the detected eccentricity a gain specific process to cancel the core volume to identify the gain of said rotation driving means for rotationally driving the disc-shaped recording medium at a constant linear velocity, output to the rotary drive means to adjust the drive signal based on the gain has a gain adjustment step of the said gain specific process, the eccentric amount of the detected in response to determining not valid, identifies the fixed gain predetermined and the gain And features.

  An information processing apparatus according to claim 4 made in accordance with the present invention to solve the above problems, the rotation control apparatus according to claim 1 or 2, and reading means for reading information recorded on the disk-shaped recording medium, And information processing means for processing the information read by the reading means so as to be output.

  The best mode of a rotation control device, a rotation control method, and an information processing device according to the present invention will be described below with reference to the drawing of FIG. FIG. 1 is a configuration diagram showing an example of a basic configuration of a rotation control device and an information processing device according to the present invention.

  In FIG. 1, the rotation control device 2 includes a rotation drive unit 20 that rotates the disk-shaped recording medium 5, and a drive signal that drives the rotation of the disk-shaped recording medium 5 at a constant linear velocity. In the rotation control device 2 having drive control means 32 for controlling drive, an eccentricity detection means 31 for detecting the eccentricity of the disc-shaped recording medium 5 and an eccentricity detected by the eccentricity detection means 31. The drive control based on the gain specified by the gain specifying means 33a, the gain specifying means 33a for specifying the gain of the rotation drive means 20 for canceling the lead amount and rotating the disk-shaped recording medium 5 at a constant linear velocity. Gain adjusting means 32 for adjusting the drive signal of the means 32 and outputting it to the rotational drive means 20.

  According to this rotation control device 2, when the eccentric amount of the disc-shaped recording medium 5 is detected by the eccentric amount detecting means 31, the eccentric amount is canceled and the disc-shaped recording medium 5 is rotationally driven at a constant linear velocity. The gain of the rotation driving means 20 that is to be specified is specified by the gain specifying means 33a. Then, the gain adjustment means 32 adjusts the drive signal of the drive control means 32 based on the gain and outputs it to the rotation drive means 20. Then, the disc-shaped recording medium 5 is rotationally driven at a constant linear velocity by canceling the eccentricity by the rotational driving means 20.

  The rotation control method is a rotation control method in which the rotation driving means 20 for rotating the disk-shaped recording medium 5 is controlled by a drive signal for making the rotation driving of the disk-shaped recording medium 5 constant in linear velocity. The eccentricity of the recording medium 5 is detected, the detected eccentricity is canceled, the gain of the rotational driving means 20 for rotationally driving the disc-shaped recording medium 5 at a constant linear velocity is specified, and based on the gain Then, the rotational driving means 20 is controlled by adjusting the driving signal.

  According to this rotation control method, when the amount of eccentricity of the disc-shaped recording medium 5 is detected, the gain of the rotational driving means 20 that cancels the amount of eccentricity and rotationally drives the disc-shaped recording medium 5 at a constant linear velocity is specified. The drive signal of the drive control means 32 is adjusted based on the gain and output to the rotation drive means 20.

  According to the rotation control device 2 and the rotation control method described above, when the eccentricity of the disk-shaped recording medium 5 to be rotated is detected, the eccentricity is canceled and the disk-shaped recording medium 5 is rotated at a constant linear velocity. Since the gain of the rotational driving means 20 for driving is specified and the drive signal is adjusted by the gain to control the rotational driving means 20, the detected eccentricity of the disk-shaped recording medium 5 is obtained. Since the gain can be set accordingly, any disk-shaped recording medium 5 can be rotated at a constant linear velocity. Therefore, since the electrical gain is only adjusted according to the amount of eccentricity, there is no need to provide new components, mechanisms, or the like in the configuration, so that the eccentricity of the disc-shaped recording medium 5 is canceled without increasing the cost. be able to.

  Further, the rotation control device 2 has a legitimacy judging means 33b for judging the legitimacy of the eccentric amount detected by the eccentric quantity detecting means, and responds to the judgment that the legitimacy judging means 33b is not legitimate. Thus, the gain specifying means 33a specifies a predetermined fixed gain as the gain.

  According to the rotation control device 2, the validity of the eccentricity detected by the eccentricity detection means 31 is determined by the validity determination means. If it is determined to be valid, the gain according to the eccentricity is specified by the gain specifying means 33a as described above. On the other hand, when it is determined that it is not valid, a predetermined fixed gain is specified as a gain by the gain specifying means 33a.

  The correctness of the eccentricity detected in this way is determined, and when the eccentricity is not valid, a predetermined fixed gain is specified as the gain, so that an abnormal gain is specified. Therefore, abnormal rotation driving of the disk-shaped recording medium 5 can be prevented.

  Further, the information processing apparatus 1 includes the rotation control device 2 according to claim 1, the reading unit 10 that reads information recorded on the disk-shaped recording medium 5, and the information that the reading unit 10 reads. Information processing means 40 for processing so as to be outputable.

  According to this information processing apparatus 1, the disk-shaped recording medium 5 is rotationally driven by the rotation control device 2 in a state where the eccentricity is canceled out. When information is read from the rotating disk-shaped recording medium 5 by the reading means 10, the information processing means 40 processes the information so that it can be output from an output means such as a speaker or a display device.

  As described above, the rotation control device 2 rotationally drives the disk-shaped recording medium 5 so that the eccentricity of the disk-shaped recording medium 5 is canceled and the linear velocity becomes constant. Thus, the information can be read constantly, and the error rate can be reliably prevented from changing. Therefore, since the control of the reading unit 10 can be simplified, the processing load is reduced and stable information processing can be performed.

  Next, embodiments of the rotation control device and the information processing device described above will be described below with reference to the drawings of FIGS. In addition, the same code | symbol is attached | subjected and demonstrated to the part which is the same as that of what was demonstrated in the basic structure shown in FIG. 1 mentioned above.

  In FIG. 2, the information processing apparatus 1 acquires information recorded on a disk-shaped recording medium 5 mounted at a predetermined position and processes the information so that it can be output. The information processing apparatus 1 includes a reading unit 10 serving as a reading unit, a rotation driving unit 20 serving as a rotation driving unit, a control unit 30, and an information processing unit 40 serving as an information processing unit. .

  As the disk-shaped recording medium 5 (hereinafter also referred to as a disk), for example, CD-DA (Compact Disk-Digital Audio), CD-ROM (Compact Disk-Read Only Memory), DVD-ROM (Digital Versatile Disc-Read). Only Memory), DVD-R (Digital Versatile Disc-Recordable), DVD-RW (Digital Versatile Disc-ReWritable), MD (MiniDisc), MO (Magneto-OpticalD), MO (Magneto-OpticalD). Note that the present invention is not limited to these, and any recording medium such as a disk-shaped recording medium on which information can be recorded and a disk-shaped recording medium on which information is recorded can be targeted.

  The reading unit 10 reads information recorded on the disk-shaped recording medium 5. The reading unit 10 includes an optical pickup 11, a feed motor (not shown), and a reading driver 12. The optical pickup 11 is located in the vicinity of the disc-shaped recording medium 5 mounted at a predetermined position, and the information recording surface on which information is recorded on the disc-shaped recording medium 5 is irradiated with laser light from the information recording surface. Information is acquired as an electrical signal by receiving reflected light that is reflected and photoelectrically converting the reflected light. The feed motor moves the optical pickup 11 parallel to the information recording surface of the disc-shaped recording medium 5 and along the radial direction thereof. The reading driver 12 drives a focus actuator and a tracking actuator (not shown) provided on the optical pickup 11 to adjust the focal distance from the information recording surface of the light emitted from the optical pickup 11 and the irradiation position on the information recording surface. .

  The rotation drive unit 20 drives the disk-shaped recording medium 5 mounted at a predetermined position of the information processing apparatus 1 to rotate at a constant linear velocity. The rotation drive unit 20 includes a holding unit (not shown), a spindle motor 21, and a spindle driver 22. The holding means holds the disk-shaped recording medium 5 in a rotatable manner. The spindle motor 21 is connected to the holding means and rotationally drives the holding means. The spindle driver 22 drives the spindle motor 21 so as to rotationally drive the disc-shaped recording medium 5 at a constant linear velocity with a variable rotational velocity.

  The rotation control unit 30 controls the rotation driving state of the disk-shaped recording medium 5 by the rotation driving unit 20. The rotation control unit 30 includes an eccentricity amount detection unit 31 that is an eccentricity amount detection unit, a signal processing unit 32 as a drive control unit, a calculation unit 33, and a gain adjustment unit 34 as a gain adjustment unit. Have.

  The eccentricity detection unit 31 detects the eccentricity of the disk-shaped recording medium 5 that is rotationally driven. For example, when the information is read from the disk-shaped recording medium 5 that is rotationally driven by the optical pickup 11, this eccentricity amount is a driving voltage level that is obtained from the driving voltage value that the reading driver 12 applies to the tracking actuator and the sensitivity of the tracking actuator. Detected by reading. When the disk-shaped recording medium 5 is rotated at a constant linear velocity, the tracking actuator drive voltage level varies due to the eccentricity of the disk-shaped recording medium 5. That is, when the eccentricity of the disk-shaped recording medium 5 that is driven to rotate varies, it is necessary to control the driving of the optical pickup 11 in the tracking direction so as to follow the eccentricity.

  The signal processing unit 32 performs tracking servo control based on information obtained from the optical pickup 11, but when the disk-shaped recording medium 5 is decentered, the amount of reflected light reflected from the information recording surface is reduced. The tracking actuator sensitivity decreases. Then, tracking servo control is performed to adjust the irradiation position, and the drive voltage value applied to the tracking actuator is varied. Depending on the magnitude of the eccentricity, the drive voltage value applied to the tracking actuator of the reading driver 12 varies. That is, the amount of eccentricity of the disc-shaped recording medium 5 can be detected by monitoring the variation in the drive voltage level obtained from the sensitivity of the tracking actuator and the drive voltage value applied to the tracking actuator. The eccentricity detection unit 31 outputs the drive voltage level to the computing unit 33 as eccentricity information.

  The signal processing unit 32 is connected to the spindle driver 22, the calculation unit 33, and the information processing unit 40 via the optical pickup 11, the reading driver 12, and the gain adjustment unit 34. The signal processing unit 32 recognizes the driving states of the focus actuator and tracking actuator of the optical pickup 11 and controls the reading driver 12 to control the driving of the focus actuator and tracking actuator. Further, the signal processing unit 32 controls the spindle driver 22 (spindle servo control) so as to rotate the disk-shaped recording medium 5 at a constant linear velocity.

  Further, the signal processing unit 32 acquires an electrical signal output from the optical pickup 11 and performs predetermined signal processing, and outputs the information subjected to the signal processing to the information processing unit 40. The circuit configuration of the signal processing unit 32 is, for example, a PLL (Phase Locked Loop) circuit and the like, and has a simple circuit configuration that rotates the disk-shaped recording medium 5 at a constant linear velocity.

  The calculation unit 33 controls the entire information processing apparatus 1. The calculation unit 33 controls the signal processing unit 32 to control the spindle driver 22 to rotate the disk-shaped recording medium 5 at a constant linear velocity (hereinafter referred to as linear velocity processing). To explain).

  The calculation unit 33 uses a known microprocessor unit (MPU), DSP (Digital Signal Processor), or the like. And the calculating part 33 has memorize | stored the various programs for functioning as a gain specific | specification means and a validity determination means in a claim in the internal memory which is not shown in figure.

  The calculator 33 executes the gain setting process shown in FIG. 3 at an arbitrary timing. Note that the timing is executed when the disc-shaped recording medium 5 is loaded, when information is reproduced, and the like.

  When the gain setting process is executed, 0 is set to a counter n that counts the number of times the eccentricity is detected in step S11. In step S12 (validity determination means), it is determined whether or not the counter n is smaller than a predetermined determination threshold value X. If it is determined that the value is smaller than the determination threshold X (Y in S12), the process proceeds to step S13.

  In step S13, as described above, the eccentricity detected by the eccentricity detection unit 31 is captured and stored in the built-in memory. In step S14, the eccentricity a is within a predetermined eccentricity detection range. By determining whether or not there is, it is determined whether or not the eccentricity a is normal. If it is determined that the eccentricity is normal (Y in S14), the process proceeds to step S15 because the eccentricity a is within the eccentricity detection range.

  In step S15 (gain specifying means), an optimum gain is specified for the eccentricity a of the loaded disk-shaped recording medium 5. For example, the calculation unit 33 stores a gain specifying table corresponding to the eccentricity range range and the gain with respect to the eccentricity a shown in FIG. The gain identification table includes the gain G1 when each eccentricity range range is greater than the eccentricity a1 and equal to or less than the eccentricity a2, and the gain G2 when the eccentricity a2 is greater than the eccentricity a2 and equal to or less than the eccentricity a3. The gain G3 is greater than the eccentric amount a4 and less than the eccentric amount a4, and the gain G4 is greater than the eccentric amount a4 and less than the eccentric amount a5. That is, the eccentric amount range section of the eccentric amount a is specified, and the gains G1 to G4 corresponding to the range section are specified as the gain G.

  In step S <b> 16, a gain change request for the specified gain G is output to the gain adjustment unit 34, so that the gain adjustment unit 34 changes the gain and the process ends.

  If it is determined in step S14 that the eccentricity a is not normal, that is, abnormal (N in S14), the current counter n is incremented in step S17, and the calculation result is assigned to the counter n (n = N + 1), the process returns to step S12 to repeat a series of processes.

  If it is determined in step S12 that the value is not smaller than the determination threshold value X, that is, the value of the counter n is larger than the determination threshold value X (N in S12), the eccentricity amount is not valid (abnormal). In step S18, the fixed gain G0 is specified as the gain G. Thereafter, the process proceeds to step S16 described above, and the gain adjustment unit 34 is changed to the fixed gain, and the process is terminated.

  In this embodiment, the case where the gain is specified using the gain specifying table will be described. However, the present invention is not limited to this, and the optimum is based on the eccentricity and gain conversion formula. Various embodiments such as calculating and specifying the gain can be made.

  Further, when specifying the gain from the eccentricity and gain conversion formula, the determination of the correctness for the eccentricity a in the flowchart of FIG. 3 is canceled, and the correctness of the gain G specified by the conversion formula is determined. I will respond.

  The gain adjustment unit 34 is connected to the signal processing unit 32, the calculation unit 33, and the spindle driver 22. The gain adjustment unit 34 has a gain switching circuit (not shown), and the gain switching circuit switches the circuit stepwise so that the gain according to the gain change request from the calculation unit 33 is obtained as described above. It has a configuration that can be performed. Then, the drive signal from the signal processing unit 32 to the spindle motor 21 is adjusted by the gain and output to the spindle motor 21, so that the spindle motor 21 cancels the eccentricity a and the linear velocity is constant and the disc-shaped recording medium 5. Is driven to rotate.

  In the present embodiment, the case where the gain adjusting unit 34 is interposed between the signal processing unit 32 and the spindle driver 22 has been described. However, the gain adjusting unit 34 is incorporated in the signal processing unit 32 and the spindle driver 22 and various other embodiments. can do.

  The information processing unit 40 is connected to the signal processing unit 32 and the calculation unit 33. The information processing means 40 acquires an electrical signal corresponding to the information from the optical pickup 11 acquired by the signal processing unit 32 and processes it appropriately. For example, the electrical signal read and converted by the optical pickup 11 is decoded into image data or music data and output to output means such as a speaker or a display device connected to the information processing unit 40. The recorded information is processed so as to be reproducible. Information processed by the information processing unit 40 is appropriately output to output means.

  Next, the operation (action) of the information processing apparatus 1 described above will be described.

  When the disc-shaped recording medium 5 is mounted at a predetermined position, the information processing apparatus 1 detects a decentering amount a of the disc-shaped recording medium 5 by the decentering amount detection unit 31 and obtains a gain for canceling the decentering amount. The gain is specified in the calculation unit 33 and the gain is set in the gain adjustment unit 34. Then, a signal indicating that linear velocity processing is performed is supplied from the arithmetic unit 33 to the signal processing unit 32, and the signal processing unit 32 drives the spindle motor 21 to rotate the disk-shaped recording medium 5 at a constant linear velocity. Is output. The drive signal is gain-adjusted by the gain adjustment unit 34 and output to the spindle driver 22, and the spindle motor 21 is driven by the spindle driver 22. At this time, since the drive signal is adjusted with the gain specified according to the eccentricity a of the disk-shaped recording medium 5, the linear velocity of the disk-shaped recording medium 5 is kept constant with the eccentricity a canceled. The rotation is controlled.

  Then, by driving the spindle motor 21, information is read by the optical pickup 11 from the disc-shaped recording medium 5 that is rotationally driven at a constant linear velocity, and is appropriately processed by the information processing hand 40, and output means (not shown) To playback and processing.

  According to the information processing apparatus 1 described above, when the amount of eccentricity of the disk-shaped recording medium 5 to be rotationally driven is detected, the amount of eccentricity is canceled and the disk-shaped recording medium 5 is rotationally driven at a constant linear velocity. Since the gain of the rotary drive unit 20 is specified and the drive signal is adjusted by the gain to control the drive of the rotary drive unit 20, the gain is set according to the detected eccentricity of the disk-shaped recording medium 5. Therefore, any disk-shaped recording medium 5 can be rotated at a constant linear velocity. Therefore, since the electrical gain is only adjusted according to the amount of eccentricity, there is no need to provide new components, mechanisms, or the like in the configuration, so that the eccentricity of the disc-shaped recording medium 5 is canceled without increasing the cost. be able to.

  In addition, the correctness of the detected eccentricity is judged, and when the eccentricity is not valid, a predetermined fixed gain is specified as the gain, thereby preventing an abnormal gain from being specified. Therefore, the abnormal rotation drive of the disk-shaped recording medium 5 can be prevented.

  In this way, the information processing apparatus 1 rotationally drives the disc-shaped recording medium 5 so that the eccentricity of the disc-shaped recording medium 5 is canceled and the linear velocity is constant. Thus, the information can be read constantly, and the error rate can be reliably prevented from changing. Therefore, since the control of the reading unit 10 can be simplified, the processing load is reduced and stable information processing can be performed.

  In the above-described embodiment, the case where the rotation control device is realized by the rotation driving unit 20, the signal processing unit 32, and the calculation unit 33 of the information processing device 1 has been described. However, the present invention is not limited to this. Various embodiments such as realization as a separate device from the information processing apparatus 1 can be adopted.

  In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

It is a block diagram which shows an example of the basic composition of the rotation control apparatus and information processing apparatus which concern on this invention. It is a block diagram which shows an example of a structure of the information processing apparatus incorporating a rotation control apparatus. It is a flowchart which shows an example of the gain setting process which the calculating part in FIG. 2 performs. It is a figure for demonstrating an example of the table which shows the relationship between eccentricity amount range division and a gain. It is a figure for demonstrating the eccentric amount of a disk-shaped recording medium, (a) shows the state which the pickup is reading the A point, (b) shows the state rotated 180 degrees from the state of (a), respectively. Yes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information processing apparatus 2 Rotation control apparatus 5 Disc-shaped recording medium 10 Reading means 20 Rotation drive means (rotation drive part)
31 Eccentricity detection means (eccentricity detection unit)
32 Drive control means (signal processing unit)
33a Gain specifying means (calculation unit)
33b Validity determination means (calculation unit)
34 Gain adjusting means (gain adjusting unit)
40 Information processing means (information processing section)

Claims (4)

A rotation control device comprising: a rotation drive unit that rotationally drives the disk-shaped recording medium; and a drive control unit that controls the drive of the rotation drive unit with a drive signal that makes the rotation drive of the disk-shaped recording medium constant in linear velocity. In
An eccentricity detecting means for detecting the eccentricity of the disc-shaped recording medium;
Correctness determination means for determining the correctness of the eccentricity detected by the eccentricity detection means;
A gain specifying means for specifying the gain of the rotation driving means for rotating the disk-shaped recording medium at a constant linear velocity by canceling the eccentricity detected by the eccentricity detecting means;
Gain adjusting means for adjusting the drive signal of the drive control means based on the gain specified by the gain specifying means and outputting the adjusted signal to the rotation driving means;
I have a,
The rotation control device characterized in that the gain specifying means specifies a predetermined fixed gain as the gain in response to the determination that the validity determining means is not valid . The legitimacy determination means determines the legitimacy of the eccentricity by determining whether the eccentricity detected by the eccentricity detection means is within a predetermined eccentricity detection range. The rotation control device according to claim 1. In the rotation control method for controlling the rotation driving means for rotating the disk-shaped recording medium with a drive signal for making the rotation driving of the disk-shaped recording medium a constant linear velocity,
An eccentricity detection process for detecting the eccentricity of the disc-shaped recording medium ;
A legitimacy judging process for judging legitimacy of the detected eccentricity amount;
A gain specifying step of canceling the detected eccentricity and specifying the gain of the rotational drive means for rotationally driving the disc-shaped recording medium at a constant linear velocity ;
A gain adjusting process for adjusting the drive signal based on the gain and outputting the adjusted drive signal to the rotation driving means ;
Have
The rotation control method characterized in that, in the gain specifying step, a predetermined fixed gain is specified as the gain in response to the determination that the detected eccentricity is not valid . The rotation control device according to claim 1 or 2,
Reading means for reading information recorded on the disk-shaped recording medium;
Information processing means for processing the information read by the reading means so as to be output;
An information processing apparatus comprising:

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