JP2005276404A - Optical disk device, method of controlling the same , and photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device where access can be accelerated, and to provide a photographing apparatus having an optical disk device like this. <P>SOLUTION: The fastest access possible in the range of the performance limit of a spindle motor 16 and an RF signal processing part 10 is realized by accessing in a CAV mode in an inner area of the optical disk 20 where the rotational speed of the spindle motor reaches a limit, and accessing by a CLV mode in an outer area of the optical disk 20 where the frequency band of an RF signal processing part 10 reaches a limit. Thus, the maximum performance of the spindle motor 16 and the RF signal processing part 10 is exhibited, so that access performance is improved markedly without improving the performance of them unnecessarily. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus and an imaging apparatus for recording image data taken on the optical disc apparatus.

  Conventionally, tape-type recording media such as magnetic tape and magneto-optical tape have been mainly used for recording large volumes of data. However, in recent years, in optical disks such as DVDs (digital versatile discs), tapes have been used. It has become possible to handle large volumes of data comparable to type recording media. For this reason, there are an increasing number of cases where optical disks are used for these purposes.

  With optical discs, it is possible to access a target address at high speed without performing winding and feeding operations as with tape-type recording media. Therefore, when performing random access, optical discs are compared to tape-type recording media. An order of magnitude faster access is possible.

  However, since the amount of data to be processed tends to increase more and more in an apparatus that processes image data, such as a photographing apparatus, an optical disk apparatus is required to have a performance for recording / reproducing a large amount of data at a higher speed. Yes.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical disc apparatus and an optical disc control method capable of further increasing the access speed, and a photographing apparatus having such an optical disc apparatus. is there.

  An optical disc apparatus according to a first aspect of the present invention is configured to rotate an optical disc at a constant angular velocity when accessing a rotation drive unit that rotationally drives the optical disc and an area from a central track to the first track of the optical disc. And a controller that controls the rotation drive unit so as to rotate the optical disk at a constant linear velocity when driving and accessing a region from the first track to the track on the peripheral edge of the optical disk.

  Preferably, the first track is determined in advance based on the rotation performance of the optical disc included in the rotation driving unit and the reading speed from the optical disc.

  Preferably, when the control unit accesses an area from the central track to the first track of the optical disc, the optical disc has a constant angular velocity corresponding to the rotational performance of the optical disc in the rotary drive unit. Is rotated so that the optical disk is rotationally driven at a constant linear velocity in accordance with the reading speed from the optical disk when the area from the first track to the peripheral track of the optical disk is accessed. Control the drive.

  An optical disk apparatus according to a second aspect of the present invention is an optical disk apparatus that irradiates light along an information track formed on an optical disk, and includes a rotation drive unit that rotationally drives the optical disk, and an irradiation position of the light. When the rotation drive unit is controlled so that the rotation speed of the optical disc is constant when the optical disc is in the central region from the first track of the optical disc, the irradiation position is in the peripheral region of the first track. In some cases, a control unit that controls the rotation driving unit so that the irradiation position moves on the information track at a constant speed.

  Preferably, the optical disc device according to the second aspect includes an optical pickup that converts reflected light from the optical disc into the electric signal and outputs the electric light, and a signal processing unit that processes an output signal of the optical pickup. The control unit controls the rotation driving unit so that the rotation speed becomes a predetermined upper limit rotation speed that can be driven by the rotation driving unit when the rotation speed of the optical disc is controlled to be constant. When the movement speed of the light irradiation position on the information track is controlled to be constant, the rotation is performed so that the frequency of the output signal of the optical pickup becomes a predetermined upper limit frequency that can be processed by the signal processing unit. Control the drive.

  An optical disc control method according to a third aspect of the present invention is an optical disc control method for controlling the rotation of an optical disc, and when accessing an area from the central track to the first track of the optical disc, the angular velocity is constant. When the optical disk is rotationally driven to access an area from the first track to the peripheral track of the optical disk, the optical disk is rotationally driven at a constant linear velocity.

  Preferably, in the optical disc control method according to the third aspect, the first track is determined based on the rotational performance of the optical disc included in the rotation driving unit of the optical disc and the reading speed from the optical disc.

  Preferably, when the area from the central track to the first track of the optical disc is accessed, the optical disc is rotationally driven at a constant angular velocity according to the rotational performance of the optical disc in the rotational drive portion of the optical disc. When accessing the area from the first track to the track on the peripheral edge of the optical disc, the optical disc is driven to rotate at a constant linear velocity corresponding to the reading speed from the optical disc.

  An imaging apparatus according to a third aspect of the present invention is an imaging apparatus having an optical disk device that records captured image data on an optical disk, the optical disk device including a rotation drive unit that rotationally drives the optical disk, and the optical disk. When accessing the area from the central track to the first track, the optical disk is rotated at a constant angular velocity, and when accessing the area from the first track to the peripheral edge track of the optical disk, A control unit that controls the rotation driving unit so as to rotate the optical disk at a constant linear velocity.

  According to the present invention, the speed control of the optical disk is appropriately switched between a mode with a constant rotational speed and a mode with a constant linear speed, thereby limiting the linear speed due to the limit of the performance of the rotary drive unit. And the access speed can be increased.

  Hereinafter, six embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
Attempts have been made to use randomly accessible optical disks for reproducing video signals instead of magnetic tapes. For example, video equipment using an optical disk for video players and video cameras has appeared. In recent years, miniaturization of optical discs and increase in storage capacity have been achieved, and the performance of optical discs has come to meet the above objectives.
As an optical disk drive system, a CLV (constant linear velocity) system that drives an optical disk at a constant linear velocity and a CAV (constant angular velocity) system that drives an optical disk at a constant angular velocity are known, both of which have advantages and disadvantages.
On the other hand, when an optical disk is used in a small video device such as a video camera, there are restrictions on the rotational performance of a spindle motor that drives the optical disk. As a result, for example, even if an optical disc formatted to be driven at a constant linear velocity is applied to the recording medium of a video camera, the entire area of the optical disc is accessed at a desired linear velocity due to the performance limitations of a small spindle motor. You may not be able to.
Therefore, as shown in FIG. 11 to be described later, the inventors of the present invention perform CAV driving to rotate the optical disk at a constant angular velocity from the central track of the optical disk to a predetermined track. For the area up to the track on the periphery of the optical disk, it is proposed to perform CLV driving in which the optical disk is rotated at a constant linear velocity.
Such a driving method is referred to as a limited CLV (LCLV) method.

The predetermined track corresponding to the boundary between the area driven by the CAV method and the area driven by the CLV method is determined in advance based on, for example, the rotational performance of the optical disk in the spindle motor and the reading speed from the optical disk.
Further, when accessing the area from the central track of the optical disk to a predetermined track, the optical disk is rotationally driven at a constant angular velocity corresponding to the rotational performance of the optical disk of the spindle motor, and the peripheral edge of the optical disk is driven from this predetermined track. When the area up to the track is accessed, the spindle motor is controlled so that the optical disk is rotationally driven at a constant linear velocity corresponding to the reading speed from the optical disk.
As a result, in the area driven by the CAV method, the optical disk is rotationally driven at the fastest angular velocity determined by the rotational performance of the spindle motor, and in the area driven by the CLV method, the fastest reading speed of the optical disk is achieved. The optical disk can be driven to rotate. That is, the rotational performance of the spindle motor and the processing performance of the signal processing system can be maximized.

  Note that various optical disks may be exchanged and mounted on video equipment such as a video camera. In the optical disk apparatus according to the embodiment of the present invention, the optical disk may be driven not only by the LCLV method but also by the CLV method or the CAV method.

<Second Embodiment>
FIG. 1 is a diagram showing an example of the configuration of an optical disc apparatus according to an embodiment of the present invention.
1 includes an interface unit 1, a FIFO unit 2, a data processing unit 3, a writing processing unit 4, an optical pickup 5, an RF signal processing unit 10, a reading processing unit 11, and skew detection. Unit 12, vibration detection unit 13, optical pickup drive unit 14, motor control unit 15, spindle motor 16, servo control unit 17, and system control unit 18.
In the example of FIG. 1, the optical pickup 5 includes a power control unit 6, a laser diode 7, an optical system 8, and a light detection unit 9.

In the above-described configuration, the motor 16 is an embodiment of the rotational drive unit of the present invention.
The system control unit 17 is an embodiment of the control unit of the present invention.
The optical pickup 5 is an embodiment of the optical pickup of the present invention.
A unit including the RF signal processing unit 10 and the read processing unit 11 is an embodiment of the signal processing unit of the present invention.

  Hereinafter, each of these components of the optical disc apparatus shown in FIG. 1 will be described.

The interface unit 1 performs processing for inputting write data to the optical disc 20 from an external device (not shown) and processing for outputting read data from the optical disc 20 to the external device. Also, a process of passing various commands input from the external device to the system control unit 18 and a process of passing a response message issued from the system control unit 18 to the external device are performed.
The interface unit 1 performs interface processing with the external device as described above in accordance with a general-purpose interface standard such as ATA (AT Attachment).

  The FIFO unit 2 temporarily stores write data input from the interface unit 1 to the data processing unit 3 and read data output from the data processing unit 3 to the interface unit 1.

The data processing unit 3 performs various data processing on write data and read data on the optical disc 20.
For example, the write data input from the interface unit 1 is subjected to a predetermined encoding process (such as an error correction encoding process) according to a predetermined recording format of the optical disk 20 and is written in the optical disk 20 Process to convert to. In addition, the read data input from the read processing unit 11 is subjected to a decoding process opposite to the above-described encoding process to perform a process of reproducing the data before writing.

  The write processing unit 4 generates a write pulse signal used for driving the laser diode 7 based on the write data processed by the data processing unit 3. The write processing unit 4 appropriately sets the amplitude and pulse width of the write pulse signal in accordance with the type of the optical disc 20 that is the write destination.

  The power control unit 6 detects the output power of the laser diode 7 fed back from the optical system 8, and changes the amount of light emitted from the laser diode 7 so that the detected power is equal to the output power indicated in the write pulse signal. Control.

  The laser diode 7 generates laser light having power according to the control of the power control unit 6.

The optical system 8 guides the laser light generated in the laser diode 7 and converges it on the light receiving surface of the optical disc 20. In addition, part of the laser light generated in the laser diode 7 is returned to the power control unit 6, and the reflected light from the optical disk 20 is guided to the light detection unit 9.
Note that the focus position of the optical system 8 with respect to the optical disk 20 changes according to the drive of the optical pickup drive unit 14.

The light detection unit 9 converts the reflected light from the optical disk 20 into an electrical signal.
In addition to the information recorded on the optical disc 20, the light detection unit 9 includes a deviation (tracking error) between the information track of the optical disc 20 and the irradiation position of the laser beam, and a deviation of the focus of the optical system 8 with respect to the optical disc 20 (focus). Error) and the like.
For example, it has a plurality of light detection elements arranged so that the intensity of the reflected light can be detected at a plurality of symmetrical positions on the surface on which the reflected light from the optical disc 20 is incident.

  The RF signal processing unit 10 performs RF signal processing such as amplification and binarization on the electrical signal converted by the light detection unit 9 to generate read data corresponding to the recording data of the optical disc 20.

  Further, the RF signal processing unit 10 generates a signal related to the tracking error and the focus error described above according to the output signal of the light detection unit 9 and outputs the signal to the servo control unit 17. For example, processing such as addition or subtraction is performed on the detection results of the above-described plurality of light detection elements included in the light detection unit 9 to generate signals related to tracking errors and focus errors. These signals are used for servo control in a servo control unit 17 described later.

In the present embodiment, as an example, it is assumed that wobbles are formed in the information track of the optical disc 20. The wobble is a periodic meandering shape provided on the side surface of the information track. Information on the clock signal used as a reference when performing access such as writing, information on the address on the information track, etc. It is embedded in the optical disc 20 as a wobble.
The RF signal processing unit 10 extracts a periodic signal component (wobble signal) corresponding to the wobble from the output signal of the light detection unit 9 and outputs it to the read processing unit 11.

  The read processing unit 11 performs various processes on signals read from the optical disc 20. For example, a process of reproducing the reference clock signal based on the wobble signal output from the RF signal processing unit 10, a process of demodulating the wobble signal and reproducing address information on the information track, and the like are performed.

  The skew detection unit 12 detects the inclination of the light receiving surface of the optical disc 20 with respect to the irradiation light from the optical pickup 5. The inclination of the optical disc 20 is caused, for example, when the outer peripheral portion of the optical disc 20 is shaken by an impact applied in a direction parallel to the rotation axis of the optical disc 20.

  The vibration detector 13 detects vibration generated in the optical disc apparatus. For example, an acceleration sensor is used to detect the vibration.

  The optical pickup driving unit 14 moves the irradiation position of the laser beam of the optical pickup with respect to the information track and the focus position of the optical system 8 according to the control of the servo control unit 17. For example, an actuator that slides the optical pickup 5 in a direction along the surface of the optical disc 20 or in a direction perpendicular to the surface is provided.

  The motor control unit 15 controls the spindle motor 16 so that the rotation speed of the optical disc 20 is maintained at the rotation speed specified by the system control unit 18.

  The spindle motor 16 rotationally drives the optical disc 20 according to the control of the motor control unit 15.

  The servo control unit 17 is generated by the RF signal processing unit 10 so that the laser beam of the optical pickup 5 is irradiated to the designated position on the information track of the optical disc 20 while the optical system 8 is in focus. The optical pickup driving unit 14 is servo-controlled in response to a tracking error signal and a focus error signal.

  In addition, the servo control unit 17 sets the optical pickup driving unit 14 so that the servo control described above works even when vibration is caused by an external impact according to the detection result of the skew detection unit 12 or the vibration detection unit 13. Control. When there is a risk of a collision between the optical pickup 5 and the optical disc 20, the optical pickup driving unit 14 is controlled so that the collision is avoided.

  Further, the servo control unit 17 locks servo control (tracking control) for irradiating a specified position on the information track with laser light and servo control (focus control) for focusing the optical system 8 on the information track. When it comes off, this is notified to the system control unit 18.

The system control unit 18 performs various processes related to the overall operation of the optical disc apparatus.
For example, in the acquisition of an instruction from an external device input via the interface unit 1, transmission of a message to the external device, monitoring of the amount of write data or read data stored in the FIFO unit 2, in the read processing unit 11 Acquisition of address information of the optical disc 20 to be reproduced, processing instructions in the data processing unit 3 and the servo control unit 17, and the like are performed.

  In addition, when the access to the optical disc 20 fails, the system control unit 18 performs a process of trying the failed access again. In this access retry, if an access failure factor such as a servo control failure or address information read failure repeatedly occurs in a predetermined vicinity on the optical disc 20, the access has failed due to a defect in the optical disc 20. Processing to determine is performed.

  If the system control unit 18 determines that access to the designated address on the optical disc 20 has failed due to a defect in the optical disc 20, the read processing unit 11 can read the address information. For example, the access destination is changed to an address separated by a predetermined address width (first address width) from the address that has failed to be accessed. On the other hand, when the read processing unit 11 cannot read the address information (for example, when the tracking control or the focus control is completely unlocked by the servo control unit 18), a predetermined reference position of the optical disc 20 (for example, the innermost portion of the optical disc 20). If access at this reference position is possible, a predetermined address width (second address width longer than the first address width) than the address that failed to access is checked. ) To change the access destination to an address separated by a).

  Next, the operation in the case of executing read access or write access (hereinafter abbreviated as R / W access) in the optical disc apparatus shown in FIG. 1 having the above-described configuration will be described.

  2 to 4 are flowcharts illustrating an example of the R / W access process.

  In executing the R / W access, the system control unit sets the following constants.

(External factor timeout time Ts)
The external factor timeout time Ts indicates the upper limit of the time during which access retry can be repeated when access fails due to external factors such as vibration. However, the starting point of the upper limit time is when an instruction for instructing execution of write or read access to the system control unit 18 is issued from the external device.

(Upper limit number of retries at the time of defect Nd)
The upper limit number Nd of retries at the time of a defect indicates an upper limit value of the number of retries when retrying due to a defect in the optical disc 20.

(Upper limit number of retries for internal error Ni)
The retry count upper limit value Ni at the time of a defect indicates the upper limit value of the retry count when retrying due to an internal factor of the optical disc apparatus.

(Timeout time Tt before seek start)
Shows the upper limit of time during which access retries can be repeated before seeking begins. The starting point of the upper limit time is the same as the external factor timeout time Ts.

(Internal factor timeout time Ti)
The upper limit of the time during which retry can be performed when access fails due to an internal factor of the optical disk device. The starting point of the upper limit time is the same as the external factor timeout time Ts.

  These constants are given to the system control unit 18 from the external device via the interface unit 1, for example.

  When an R / W access command is issued in the external device, the system control unit 18 starts measuring time in the internal timer from the time when the command is issued.

  First, the system control unit 18 compares the timer value with the external factor timeout time Ts (step ST100), and if the timer value exceeds the upper limit, terminates the access retry, Error processing is executed (step ST102). For example, a process of notifying an external device that an error due to an external factor such as an impact has occurred is performed.

If the timer value does not exceed the external factor timeout time Ts, the system control unit 18 checks whether a seek operation is possible (step ST104).
If the seek operation is not possible, it is checked whether or not the cause is due to an address read failure (step ST106). For example, it is examined whether the address information cannot be read because the tracking control and the focus control in the servo control unit 17 are completely unlocked. If such an error does not occur and the address can be read from the optical disc 20, the process returns to step ST100 and the R / W access process is executed again.

  On the other hand, when the address information cannot be read, the system control unit 18 compares the above-described timer value with the timeout time Tt before seek start (step ST108). If the timer value does not exceed this upper limit, the process returns to step ST100 and the R / W access process is executed again. If the timer value exceeds this upper limit value, a reference position stationary operation ST110 for checking whether or not access is possible at the reference position of the optical disc 20 is executed. Reference position stationary operation ST110 will be described in detail later with reference to FIGS.

  When it is determined in step ST104 that the seek operation is possible, the system control unit 18 starts the seek operation (step ST112). In the seek operation, by moving the irradiation position of the laser beam while jumping the information track in the radial direction of the optical disc 20, 1 is performed for the track (information track for one round) including the start target address of the R / W access. The address to be accessed is jumped to the previous track.

  Until such seek operation is completed, the system control unit 18 monitors whether or not the above-described timer value exceeds the external factor timeout time Ts (steps ST114 and ST118). If the seek operation does not end due to an impact or the like and the timer value exceeds the external factor timeout time Ts, the access retry is terminated and error processing similar to step ST102 is executed (step ST116).

  When the seek operation ends, the system control unit 18 determines whether or not the seek operation has failed (step ST120).

  When the seek operation fails, the system control unit 18 determines whether or not the failure is due to a small defect error (step ST122). Here, the small defect error means an access error caused by a relatively small range of defects on the optical disc. A small defect error includes a case in which the address information cannot be read at all due to the focus control and tracking control being unlocked in the servo control unit 17 or the like.

  When the predetermined access failure factor repeatedly occurs in a predetermined vicinity range on the optical disc 20, the system control unit 18 determines that the optical disk has a defect in the vicinity range. If the access failure factor is not a failure factor that is so serious that the address information cannot be read, it is determined that the optical disc 20 has a small defect. For example, an error in which the focus control or tracking control is temporarily unlocked in the servo control unit 17 or an error in which the clock signal reproduction processing in the reading processing unit 11 becomes temporarily defective is in a predetermined vicinity on the optical disc 20. If the error repeatedly occurs in the range, it is determined that the access (seek operation in this step) has failed due to a small defect on the optical disk 20.

  When it is determined that the seek operation has failed due to a small defect on the optical disc 20, the system control unit 18 executes predetermined error processing (step ST124). For example, the R / W access start target address is changed to a position separated by a predetermined address width (first address width) from the original address where the access failed, and the R / W access is executed again.

When it is determined that the seek operation has not failed due to a small defect, the system control unit 18 determines whether or not the address information can be read from the optical disc 20 (step ST126). For example, it is determined whether or not an error has occurred in the servo control unit 17 such that the servo control is completely unlocked. If the address information cannot be read due to such an error, the system control unit 18 executes a reference position stationary operation described later (step ST128).
On the other hand, if the address information can be read, it is estimated that the error is due to vibration, so the process returns to step ST100 and the R / W access process is executed again.

  If it is determined in step ST120 that the seek operation has been completed normally, the system control unit 18 performs control to advance the irradiation position of the laser light from the address after the seek operation toward the start target address of the R / W access. Do. Then, the occurrence of a predetermined error is monitored until the target address for starting the R / W access is reached. For example, the servo controller 17 monitors the occurrence of an error that causes the focus control or tracking control to be unlocked, or the occurrence of an error that causes the laser light irradiation position to deviate from the track immediately before the start target address (step ST130, ST132, ST134).

  When such an error occurs, the system control unit 18 determines whether the error has occurred due to an external factor such as an impact (step ST136). Details of this determination will be described later in detail with reference to FIG. If it is determined that the error is caused by an external factor such as an impact, the process returns to step ST100 and the R / W access process is executed again.

  On the other hand, when it is determined that an error has occurred due to a defect in the optical disk 20, the system control unit 18 determines the total number of times (D_Retry) that has been determined that the access has failed due to a defect in the optical disk 20 in the previous retry of access. Then, it is determined whether or not the above retry count upper limit value Nd is exceeded (step ST138). If this upper limit is not exceeded, 1 is added to the total number of times D_Retry, then the process returns to step ST100, and the R / W access process is executed again. If the total number of times D_Retry exceeds the upper limit value, the access retry operation is terminated and defect error processing (see FIG. 8) described later is performed (step ST140).

  If it is determined in step ST134 that the laser beam irradiation position has reached the start target address for R / W access, the system control unit 18 determines whether or not the R / W access can be started (step ST142). For example, it is checked whether or not there is a sufficient free area in the FIFO unit 2.

  When it is determined that the R / W access cannot be started, the system control unit 18 compares the above-described timer value with the internal factor timeout time Ti (step ST144). If the timer value does not exceed the internal factor timeout time Ti, the process returns to step ST100, and the R / W access process is executed again. If it exceeds, the predetermined error process is executed (step ST146). For example, processing for notifying an external device that the start of R / W access has failed due to an internal factor such as the FIFO unit 2 is performed.

  When determining in step ST142 that the R / W access can be started, the system control unit 18 starts the R / W access (step ST148). If no error occurs during access, the R / W access process is terminated.

  On the other hand, when an error occurs during access, the system control unit 18 determines whether or not the error is caused by light emission failure of the laser diode 7 or control failure of the power control unit 6 (step ST152).

  If it is determined that such an internal factor error has occurred, the system control unit 18 determines that the total number of times that the access has failed due to the internal factor error (I_Retry) is the above retry count upper limit Ni. It is determined whether or not it exceeds. If the upper limit is not exceeded, 1 is added to the total number of times I_Retry, then the process returns to step ST100 and the R / W access process is executed again. When the total number of times I_Retry exceeds the upper limit value, predetermined internal error processing is executed (step ST156). For example, processing for notifying an external device that the R / W access has failed due to an internal factor such as the laser diode 7 is performed.

  If it is determined in step ST152 that an error has not occurred due to an internal factor such as the laser diode 7, the system control unit 18 determines whether or not the error is due to a defect in the optical disc 20 (step ST158). ). Details of this determination will be described later, as in step ST136.

  If it is determined in step ST158 that the error is not due to a defect in the optical disc 20, the system control unit 18 returns to step ST100 and executes the R / W access process again.

  On the other hand, if it is determined that an error has occurred due to a defect in the optical disc 20, the system control unit 18 determines whether or not the total number of defect determinations D_Retry exceeds the above retry count upper limit Nd (step ST160). If this upper limit is not exceeded, 1 is added to the total number of times D_Retry, then the process returns to step ST100, and the R / W access process is executed again. If the total number of times D_Retry exceeds the upper limit value, the access retry operation is terminated and defect error processing (see FIG. 8) described later is performed (step ST162).

  The above is the description of the R / W access process shown in FIGS.

Next, details of the reference position stationary operation in steps ST110 and ST128 of FIG. 2 will be described.
5 and 6 are flowcharts showing an example of processing when the reference position stationary operation is executed.

  First, the system control unit 18 performs processing for stopping operations related to R / W access (step ST200), and confirms that light emission of the laser diode 7 is stopped (step ST202).

  After confirming that the operation related to the R / W access is stopped, the system control unit 18 moves the irradiation position of the laser beam to a predetermined reference position of the optical disc 20 (for example, the innermost area of the optical disc 20) and stops the operation. The process which performs is performed (step ST204).

FIG. 6 is a flowchart showing an example of processing in step ST204.
The system control unit 18 executes a command to move the laser light irradiation position to a predetermined reference position of the optical disc 20 (step ST300), and then confirms the response from the optical pickup unit 5 that informs the end of the movement (step ST300). Step ST302).

  Upon confirming the movement of the laser light irradiation position, the system control unit 18 checks whether or not the optical disk 20 can be accessed at this reference position (step ST206). For example, it is checked whether the address information can be read at the reference position. When the optical disk 20 cannot be accessed at the reference position, or when a signal indicating that the movement of the laser light irradiation position has failed is output from the optical pickup unit 5, the system control unit 18 performs predetermined internal error processing (for example, The process of notifying the external device that the reference position stationary operation has failed due to an internal factor is executed, and the reference position stationary operation is terminated (step ST208).

  If it is possible to read the address information at the reference position, the system control unit 18 executes the seek operation again to the position where an error has occurred before calling the reference position stationary operation (step ST210). Then, processing such as reading out address information at the seek position is executed to check whether or not the seek operation has been normally completed (step ST212). As a result of the confirmation, if the seek operation can be performed normally, a process for returning to the R / W access operation is executed, and the reference position stationary operation is terminated (step ST214).

  If it is determined in step ST212 that the seek operation has failed again, the system control unit 18 again moves the laser light irradiation position to the reference position shown in FIG. 6 (step ST216), and the optical disk 20 is moved to the reference position. It is checked whether or not access is possible (step ST218). If the optical disk 20 cannot be accessed at the reference position, the system control unit 18 executes a predetermined internal error process and ends the reference position stationary operation (step ST222).

  On the other hand, when it is possible to read the address information at the reference position, the system control unit 18 determines that a large defect error has occurred at the position determined to have failed the seek operation in step ST212, and the predetermined error has occurred. Processing is executed (step ST220).

  Here, the large defect error means an access error caused by a relatively wide range of defects on the optical disc. For example, if there is a large defect extending in the circumferential direction, the servo control unit 17 completely unlocks the servo control, or the read processing unit 11 cannot reproduce the clock signal from the wobble signal at all. Cannot be read. Such a case is included in the large defect error.

  When it is determined that a major defect has occurred on the optical disc 20, the system control unit 18 sets, for example, a start target address for R / W access to a predetermined address width (second address) from the original address at which access failed. Change to a position separated by (width) and execute the R / W access again. The second address width in this case is set longer than the first address width when it is determined that a small defect has occurred. That is, the width of the address to be changed is appropriately set according to the predicted defect size.

  The above is the description of the reference position stationary operation shown in FIGS.

Next, error factor determination processing in step ST136 of FIG. 3 and step ST158 of FIG. 4 will be described.
FIG. 7 is a flowchart showing an example of error cause determination processing for determining whether an access error is caused by a defect or vibration of the optical disc.

First, the system control unit 18 repeatedly causes a servo control failure of the servo control unit 17 (servo control lock is temporarily released, etc.) repeatedly in a predetermined vicinity range on the optical disc 20 during the access retry. It is determined whether or not (step ST400).
For example, whether or not the interval between the position on the optical disc 20 that caused the servo control failure in the previous access error and the position on the optical disc 20 that caused the servo control failure in the current access error is shorter than a predetermined distance. judge.
If it is determined that a servo control failure has repeatedly occurred in the vicinity, the system control unit 18 determines that an access error has occurred due to a defect in the optical disc, and ends the error cause determination process (step ST412). .

If it is determined in step ST400 that the servo control failure has not repeatedly occurred in the vicinity range, the system control unit 18 next determines whether or not the rotational speed control failure has occurred in the motor control unit 15 when the access fails. (Step ST402).
Since a defective rotation speed control cannot occur due to a defect in the optical disc 20, if the rotation failure control has occurred in the motor control unit 15 at the time of access failure, the system control unit 18 causes an access error due to vibration. The error cause determination process is terminated (step ST414).

If it is determined in step ST402 that there is no rotational speed control failure at the time of access failure, the system control unit 18 next performs a clock signal regeneration process failure (clock signal of the clock signal) of the read processing unit 11 in the access retry. It is determined whether or not the PLL circuit used for reproduction is unlocked repeatedly in a predetermined vicinity on the optical disc 20 (step ST404).
If it is determined that the failure in the clock signal reproduction process has repeatedly occurred in the vicinity range, the system control unit 18 determines that an access error has occurred due to a defect in the optical disc, and ends the error cause determination process (step S1). ST412).

If it is determined in step ST404 that the failure of the clock signal reproduction process has not repeatedly occurred in the vicinity range, the system control unit 18 next determines the inclination of the optical disc 20 detected by the skew detection unit 12 when access fails. It is determined whether or not the threshold value is exceeded (step ST406).
Since the inclination of the optical disk 20 cannot occur due to a defect in the optical disk 20, when an inclination exceeding a threshold is detected when access fails, the system control unit 18 determines that an access error has occurred due to vibration, The error cause determination process is terminated (step ST414).

If it is determined in step ST406 that an inclination exceeding the threshold is not detected at the time of access failure, the system control unit 18 next determines that the address information reproduction process of the read processing unit 11 is defective in the access retry. It is determined whether or not it repeatedly occurs in a predetermined vicinity range on 20 (step ST408).
If it is determined that the failure in the address information reproduction process has repeatedly occurred in the vicinity, the system control unit 18 determines that an access error has occurred due to a defect in the optical disc, and ends the error cause determination process (step S1). ST412).

If it is determined in step ST408 that the failure of the address information reproduction process has not repeatedly occurred in the vicinity range, the system control unit 18 next detects the vibration detected by the vibration detection unit 13 when the access fails. Is determined (step ST410).
Since vibration cannot occur due to a defect in the optical disc 20, when vibration exceeding a threshold is detected when access fails, the system control unit 18 determines that an access error has occurred due to vibration, and determines the cause of the error. The process ends (step ST414).

  On the other hand, if it is determined in step ST410 that vibration exceeding the threshold is not detected at the time of access failure, the system control unit 18 determines that an access error has occurred due to a defect in the optical disc, and causes error cause determination processing. Is terminated (step ST412).

  The above is the description of the error cause determination process shown in FIG.

Next, the defect error processing in step ST140 in FIG. 3 and step ST162 in FIG. 4 will be described.
FIG. 8 is a flowchart illustrating an example of defect error processing that is executed when the determination that access has failed due to a defect in the optical disc 20 is repeated more than the upper limit number of times.

  First, the system control unit 18 determines whether or not the address information can be read from the optical disc 20 (step ST500). For example, it is determined whether or not an error has occurred in the servo control unit 17 such that the servo control is completely unlocked. When such an error does not occur and the address information can be read, the system control unit 18 changes the access destination to an address separated by the first address width and executes the R / W access again. The defect error process is terminated (step ST502). In this case, the system control unit 18 estimates the defect of the optical disc 20 as the small defect described above, and sets the address change width.

  If it is determined in step ST500 that the address information cannot be read, the system control unit 18 searches for a readable address within a predetermined address range from the address that has failed to be accessed (step ST504). If there is a readable address within this address range, it is determined that the access destination is changed to this address and the R / W access is executed again, and the defect error processing is terminated (step ST506).

  If it is determined in step ST504 that there is no readable address within the predetermined address range, the system control unit 18 irradiates a laser beam to investigate whether access is possible at the reference position of the optical disc 20. Processing for moving the position to the reference position is performed (steps ST508, ST510, ST512, ST514). This process is the same as steps ST200, ST202, ST300, ST302 already described.

  Upon confirming the movement of the laser light irradiation position, the system control unit 18 checks whether or not the optical disk 20 can be accessed at this reference position (step ST516). For example, it is checked whether the address information can be read at the reference position. When the optical disk 20 cannot be accessed at the reference position, or when a signal indicating that the movement of the laser beam irradiation position has failed is output from the optical pickup unit 5, the system control unit 18 executes predetermined internal error processing. Then, the defect error process is terminated (step ST518).

  If the address information can be read at the reference position, the system control unit 18 determines to change the access destination to an address separated by the second address width and execute the R / W access again, and The error process is terminated (step ST520). In this case, the system control unit 18 estimates the defect of the optical disc 20 as the above-described large defect and sets the address change width.

As described above, according to the optical disk apparatus according to the present embodiment, in an access retry, a predetermined access failure factor such as a servo control defect or a clock signal reproduction process defect is present in a predetermined neighborhood range on the optical disk 20. If the error occurs repeatedly, it is determined that access has failed due to a defect in the optical disk.
Therefore, the access failure caused by the defect of the optical disc 20 can be clearly discriminated from the access failure caused by another cause. As a result, it is possible to perform appropriate processing for an access failure caused by a defect in the optical disc 20.

In the optical disk apparatus according to the present embodiment, when an access failure such as a servo control failure or a clock signal reproduction process failure does not repeatedly occur in the vicinity of the optical disk 20 during an access retry, an access failure occurs. If the vibration detected by the vibration detector 13 exceeds a predetermined threshold, it is determined that the access has failed due to the vibration, and if the detected vibration does not exceed the predetermined threshold, the optical disc It is determined that the access has failed due to 20 defects.
Therefore, it is possible to clearly discriminate between an access failure caused by a defect in the optical disc and an access failure caused by externally applied vibration. As a result, it is possible to reduce an erroneous determination of an access failure due to an optical disc defect and an access failure due to vibration, and appropriate error processing can be performed according to each failure cause.

Furthermore, in the optical disk device according to the present embodiment, when the determination that access has failed due to a defect in the optical disk is repeated beyond the upper limit Nd of retry times, the access retry is terminated and defect error processing is executed. Is done. When the determination that the access has failed due to vibration is repeated beyond the external factor timeout time Ts, the access retry is terminated and a predetermined error process by an external factor is executed.
Accordingly, it is possible to set different conditions for shifting to error processing depending on whether access fails due to a defect in the optical disk or access fails due to vibration.

  Normally, when access fails due to an optical disc defect, access is often not successful even after repeated access retries. In this case, if the number of retries is too large, useless processing time will be lengthened. . On the other hand, when access fails due to vibration, there is a high possibility that access will be possible after a certain time, so it is necessary to set a large number of retries. According to the present embodiment, it is possible to clearly distinguish between an access failure due to an optical disc defect and an access failure due to vibration, and to appropriately set an access retry time and an upper limit of the number of retries according to the determined cause of failure. Therefore, it is possible to perform appropriate error processing according to the cause of the failure while suppressing a wasteful processing time due to the retry.

In addition, according to the optical disc apparatus according to the present embodiment, it is possible to read the address information from the optical disc 20 when access to a designated address on the optical disc 20 fails due to a defect of the optical disc 20. For example, the access destination is changed to an address separated by the first address width from the address that failed to be accessed. On the other hand, if the address information cannot be read, it is checked whether or not access is possible at a predetermined reference position on the optical disc 20. As a result of this investigation, if access at the reference position is possible, the access destination is changed to an address separated by a second address width longer than the first address width from the address at which access failed.
Therefore, when the estimated size of the defect is estimated to be relatively large, the access destination is changed to a position farther away than when the estimated size is smaller than this, and access is skipped. It is possible to achieve successful access while suppressing an increase in storage area.

  In particular, when writing data to be transmitted in real time to an optical disk, it is desirable to resume writing as soon as possible because there is a possibility that overflow will occur in the FIFO unit 2 if the delay of the writing process due to access failure is prolonged. On the other hand, according to the above-described method of skipping the access destination to a position separated by a preset address width, writing can be resumed at a higher speed than the method of searching for accessible addresses endlessly. 2 overflow can be effectively avoided.

<Third Embodiment>
Next, a third embodiment of the present invention will be described.
The third embodiment is an embodiment related to determining whether or not the tracking error has increased beyond a certain limit.

  FIG. 9 is a diagram illustrating a configuration example of a portion related to tracking error determination in the optical disc device according to the present embodiment. 9 and 1 denote the same components. The configuration of the optical disc apparatus other than the portion shown in FIG. 9 is the same as that of the optical disc apparatus shown in FIG.

In the example of FIG. 9, the light detection unit 9 includes light detection elements 91 and 92. The RF signal processing unit 10 includes a differential amplification unit 101. The servo control unit 16 includes determination units 161, 162, and 163.
The unit including the determination units 161, 162, and 163 is an embodiment of the tracking error determination unit of the present invention.

  The photodetecting elements 91 and 92 convert the reflected light from the optical disk 20 incident from the optical system 8 into an electric signal. For example, as shown in FIG. 9, the photodetecting elements 91 and 92 are arranged symmetrically on a plane. When the central portion of the information track is irradiated with laser light, the output signal levels of the light detection elements 91 and 92 are substantially equal.

  The differential amplifier 101 amplifies and outputs the difference between the output signal levels of the photodetecting elements 91 and 92. The output signal TE of the differential amplifier 101 corresponds to a detected value of a deviation (tracking error) of the irradiation position of the laser beam with respect to the information track.

  When the magnitude of the output signal TE of the differential amplifier 101, that is, the magnitude of the tracking error detected by the differential amplifier 101 exceeds the threshold value THA over the time TA, the determination unit 161 detects the tracking error. It is determined that the size has reached the first error criterion.

  In the case where the vibration detected by the vibration detection unit 13 is greater than a predetermined threshold value, the determination unit 162 determines that the magnitude of the tracking error is the second when the signal TE exceeds the threshold value THB over time TB. It is determined that the error criterion is reached. However, the threshold value THB is larger than the threshold value THA, and the time TB is shorter than the time TA.

  The determination unit 163 determines that the tracking error is larger than a certain limit when the size of the tracking error reaches the first error determination criterion or the second error determination criterion in the determination unit 161 or 162. That is, a signal ERR_T indicating that a defect has occurred in tracking control is output.

  According to the configuration described above, when the vibration detected by the vibration detection unit 13 is smaller than the predetermined threshold value, it is determined whether or not the first error determination criterion is reached. When the vibration detected by the vibration detector 13 is larger than the predetermined threshold value, it is determined whether or not the second error determination criterion is reached in addition to the first error determination criterion.

FIG. 10 is a diagram illustrating waveform examples of the output signal TE of the differential amplifier 101 under various conditions.
FIG. 10A shows an example of the waveform of the signal TE when a strong impact is applied to the optical disc apparatus. In this case, the signal TE has a large peak with a relatively short time width.
FIG. 10B shows a waveform example of the signal TE when the optical disk 20 has a defect. In this case, the signal TE has a low peak for a long time compared to that at the time of impact.
FIG. 10C shows an example of the waveform of the signal TE when a fine defect has occurred in the optical disc 20. In this case, the signal TE lasts for a short time at a lower peak than at the time of impact.

  Of the cases shown in this waveform example, it is necessary to determine that the tracking error has exceeded a certain limit in the cases of FIGS. 10A and 10B. In the case of FIG. 10C, that is, when a fine defect has occurred in the optical disc 20, there is often no problem even if the access is continued as it is, so rather it is not determined that the tracking error has exceeded a certain limit. Is preferable.

  However, in the conventional optical disk apparatus, since the tracking error is generally determined based on one determination criterion, there is a problem that it is easy to confuse a case where a strong impact is applied and a case where a fine defect is generated. For example, assuming that the determination is made only with the first determination criterion (threshold value THA, time TA) in the waveform example of FIG. 10, the pulse width t2 of the signal in the cases of FIG. 10 (A) and FIG. 10 (C). , T4 are close to each other, so that it is difficult to distinguish them. In recent years, with the increase in the density of optical discs, the pulse width of fine defects has become smaller and approaches the pulse width at the time of strong impact, making it increasingly difficult to distinguish between the two.

  If the error determination standard is loosened so that a case where a fine defect has occurred is not determined as an error, a high-speed signal TE as shown in FIG. There is a risk that a delay will occur, causing problems such as overwriting of recorded contents. On the other hand, if the error determination criteria are stricter, the operation is interrupted due to error determination even in the case of a fine defect that can continue recording / reproduction.

On the other hand, according to the determination method of the optical disc apparatus according to the present embodiment described above, different determination criteria are used depending on whether the vibration detected by the vibration detection unit 13 exceeds a predetermined threshold value or not. .
That is, when the vibration detection unit 13 detects a certain level of vibration, both the first determination criterion (threshold value TA, time TA) and the second determination criterion (threshold value TB, time TB) are effective. Therefore, in addition to an error due to an optical disc defect (FIG. 10B), an error due to a strong impact (FIG. 10A) can be reliably determined.
On the other hand, when the vibration detection unit 13 does not detect a certain level of vibration, only the first determination criterion (threshold value TA, time TA) is effective, and thus a fine defect has occurred (FIG. 10C )) Can be prevented from being erroneously determined as an error.

  Therefore, according to the above-described optical disc apparatus according to the embodiment, an error caused by a strong impact can be reliably determined, so that reliability can be improved. In addition, since the number of cases in which a fine defect has occurred on the optical disc 20 is erroneously determined as an error, the recording / reproducing operation is less interrupted and the storage area that is unused due to the erroneous determination is reduced. As a result, waste of the storage area can be reduced.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described.
The fourth embodiment is an embodiment related to the control of the rotation speed of the optical disc.

  The optical disc apparatus according to the fourth embodiment has the same configuration as the optical disc apparatus shown in FIG. 1, for example. However, in connection with the control of the rotation speed of the optical disc 20, the system control unit 18 performs the following control.

In other words, the system control unit 18 instructs the motor control unit 15 so that the rotation speed of the optical disc 20 is constant when the laser-light irradiation position of the optical pickup 5 is in a region closer to the center than a predetermined track of the optical disc 20. Instruct the rotation speed. On the other hand, when the irradiation position of the laser beam is in the region on the peripheral side of the optical disc 20 from the predetermined track, the system control unit 18 moves the irradiation position on the information track of the optical disc 20 at a constant speed. The motor control unit 15 is instructed about the rotation speed.
As a result, when the distance from the center of the disk of the optical disk 20 to the laser-light irradiation position is shorter than a predetermined distance, the optical disk 20 is rotationally driven so that the rotation speed is constant. On the other hand, when the distance from the center of the disk is longer than a predetermined distance, the optical disc 20 is rotationally driven so that the speed of the irradiation position of the laser beam moving on the information track is constant.

FIG. 11 is a diagram illustrating an example of the relationship between the distance from the center of the optical disc 20 and the rotation speed of the optical disc 20.
As shown in FIG. 11, the system control unit 18 accesses the optical disc 20 in the CAV mode in which the rotation speed is kept constant when the irradiation position of the laser beam is in the range up to the distance R with respect to the center of the optical disc 20. I do. Further, at a position where the laser beam irradiation position is further than the distance R with respect to the center of the optical disk 20, the optical disk 20 is in the CLV mode which keeps the speed (linear velocity) of the laser beam irradiation position moving on the information track constant. Process to access.

In addition, the system control unit 18 sets the rotational speed in the CAV mode and the linear speed in the CLV mode as described below.
That is, when operating in the CAV mode in which the rotation speed of the optical disk is controlled to be constant, the motor control unit 15 is controlled so that the rotation speed of the optical disk 20 becomes a predetermined upper limit rotation speed that can be driven by the spindle motor 16. Specify the rotation speed.
When operating in the CLV mode in which the linear velocity is controlled to be constant, the motor control unit 15 is controlled so that the frequency of the output signal of the optical pickup 5 becomes a predetermined upper limit frequency that can be processed by the RF signal processing unit 10. Specify the rotation speed.

  Normally, the CLV mode has a higher speed when accessing a continuous area along the information track than the CAV mode. Therefore, the CLV mode is advantageous when accessing a continuous area at high speed. However, since the conventional optical disk apparatus operates in only one of the CLV mode and the CAV mode, it is necessary to sacrifice the access speed due to the performance limit of the rotational speed of the spindle motor.

  That is, in the CLV mode, it is necessary to rotate the optical disk at a higher speed toward the inner side of the optical disk, so that the linear velocity is limited by the performance limit of the rotational speed of the spindle motor. If the frequency of the RF signal from the optical pickup at this limited linear velocity is lower than the upper limit frequency that can be processed by the RF signal processing circuit, the performance of the inherent access speed can be sufficiently exhibited. There will be no.

On the other hand, according to the above-described optical disc apparatus according to the present embodiment, the area inside the optical disc 20 where the rotation speed of the spindle motor reaches the limit is accessed in the CAV mode, and the processing speed of the RF signal processing unit 10 is limited. By accessing in the CLV mode in the outer area of the optical disk 20 that reaches, it is possible to achieve access as fast as possible within the performance limits of the spindle motor 16 and the RF signal processing unit 10.
As a result, the maximum performance of the spindle motor 16 and the RF signal processing unit 10 can be exhibited, so that the access speed in the CAV mode and the data transfer rate in the CLV mode are greatly increased without wastefully improving these performances. Can be improved.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described.
The fifth embodiment relates to an increase in seek speed.

  The optical disc apparatus according to the present embodiment has the same configuration as the optical disc apparatus shown in FIG. 1, for example, and accesses an optical disc as described below.

  In other words, the optical disc to be accessed in this embodiment has information tracks formed in a spiral shape, and each information track is divided into a plurality of sections each assigned an address. In each section, information necessary for reproducing the assigned address is continuously recorded along the information track.

An optical disc having such a structure corresponds to, for example, an optical disc conforming to a standard called Blu-ray.
The information track of the Blu-ray disc is divided into 64 Kbyte sections called RUBs. One RUB is further divided into three sections, and one address information is recorded in each of the three sections.
The address information in the section is continuously recorded along the information track by a method of modulating the periodic shape of the wobble according to the address information. Therefore, in order to reproduce one piece of address information, it is necessary to trace a 1/3 partition of 1RUB.

  When moving the irradiation position of the laser beam in the circumferential direction of such an optical disk, the general optical disk apparatus moves the irradiation position in one predetermined direction along the information track. For example, the laser light irradiation position is not moved in the reverse direction during access. Therefore, when a seek operation for moving the irradiation position of the laser beam in the radial direction of the optical disk is performed, the following problem occurs.

FIG. 12 is a diagram illustrating an example of a seek operation in a general optical disc apparatus.
In FIG. 12, symbols 'T (n-1)', 'T (n)',... Each indicate a track, and symbols 'S (i)', 'S (i + 1)',. Indicates the compartment. Symbols “A1” to “A3” indicate addresses on the information track.
It is assumed that the optical disk apparatus moves the irradiation position of the laser light in one direction in the order of tracks T (n−1), T (n), T (n + 1),.

  In the example of FIG. 12A, the address A2 before the seek operation is located in the track T (n−1), and the access target address A1 is located in the track T (n + 1). When the seek operation is normally executed, the irradiation position of the laser beam moves to the address A3 of the track T (n) immediately before the track T (n + 1) of the access target address A1.

In a general optical disc apparatus, since the address jumps to the track immediately before the track where the access target address is located, for example, as shown in FIG. There is a case where it is included in a section S (i) immediately before the section S (i + 1) including the address A1. As described above, since it is necessary to perform tracing for one section in order to reproduce one address information, in this case, reproduction is performed first when tracing is performed from address A3 to address A1. The address information to be processed is the address information of the partition S (i + 1). When the address information of the section S (i + 1) is obtained, the optical disc apparatus can determine whether or not the seek operation has been performed correctly. At that time, the address A1 to be accessed has already been determined. The irradiation position has passed. Since it is not possible to trace in the reverse direction from this position, in this case, the optical disc apparatus once tries to access the address A1 by tracing again on the information track after returning to the track T (n).
That is, in a general optical disc apparatus, when performing a trace operation for acquiring address information of a partition, there is a case where the seek target address is passed, and in this case, the seek operation and the trace operation need not be repeated wastefully. There is a problem that must not be.

  On the other hand, in the system control unit 18 of the optical disc apparatus according to the present embodiment, when performing a seek operation for moving the irradiation position of the laser beam in the radial direction of the optical disc 20 toward the address to be accessed, the laser after the seek operation is performed. The number of tracks (number of tracks) of the information track jumping in the radial direction is determined so that the light irradiation position is included in at least two sections before the section to be accessed in the above-described order in one direction.

  For example, as shown in FIG. 13, the address A3 after the seek is included in a section S (i−1) that is two before the section S (i + 1) that includes the address A1 to be accessed. Therefore, when the trace operation is performed from the position after seek, the address information reproduced first is the address information of the section S (i). This address information can be acquired before the irradiation position of the laser beam reaches the address A1 to be accessed. Therefore, the system control unit 18 can access the address A1 without returning after confirming that the seek operation has been normally performed based on the acquired address information.

  The system control unit 18 may perform a process of detecting an address information read error after the seek operation. That is, after the seek operation is finished, a trace operation is performed to acquire the address information of two sections adjacent on the information track from the read processing unit 11, and according to the acquired two address information, the address information A read error may be detected. For example, the detection of the read error is performed by checking whether or not the addresses indicated by the acquired two pieces of address information are continuous.

When such address information read error detection is performed, it is necessary to set the irradiation position of the laser beam after seek in a section one before the case shown in FIG. 13 (FIG. 14).
That is, when performing the seek operation, the stem control unit 18 determines the number of tracks jumping in the radial direction so that the irradiation position of the laser beam after seek is included in the section at least three before the section to be accessed. . After moving the irradiation position of the laser beam according to this determination, the system control unit 18 performs a process of detecting the address information read error described above.

  For example, as shown in FIG. 14, the address A3 after the seek is included in a section S (i-2) that is three before the section S (i + 1) that includes the address A1 to be accessed. When the trace operation is performed from the address A3 after the seek, the address information of the sections S (i-1) and S (i) is obtained, and the section S (i + 1) of the address A1 is reached. Therefore, the system control unit 18 confirms that the seek operation has been normally performed based on the acquired two address information and that no address information read error has occurred. It becomes possible to access the address A1.

<Sixth Embodiment>
Next, a sixth embodiment of the present invention will be described.
FIG. 15 is a block diagram showing an example of the configuration of an imaging apparatus according to the sixth embodiment of the present invention.
The imaging apparatus illustrated in FIG. 15 includes an imaging unit 100, an image data processing unit 200, a display unit 300, and an optical disc device 400.

  The imaging unit 100 captures a moving image or a still image and generates the image data.

The image data processing unit 200 performs predetermined image processing such as encoding processing, filtering processing, and pixel number conversion processing on the image data output from the imaging unit 100 and records the image data on the optical disc device 400.
In addition, predetermined image processing such as decoding processing, filtering processing, and pixel number conversion processing is performed on the image data read from the optical disc apparatus 400 to generate an image signal to be supplied to the display unit 300.

  The display unit 300 displays an image corresponding to the image signal supplied from the image data processing unit 200.

  The optical disc apparatus 400 is one of the above-described optical disc apparatuses according to the first to fifth embodiments, and records and reproduces image data in accordance with an instruction from the image data processing unit 200.

According to the photographing apparatus having the above-described configuration, in the optical disc apparatus 400, it is possible to clearly discriminate between an access failure caused by a defect of the optical disc and an access failure caused by vibration applied from the outside. Therefore, it is possible to perform appropriate error processing according to the image data, so that the reliability of the image data recording operation can be improved.
In addition, even when access fails due to vibration or the like, the recording operation can be quickly restored, so that loss of image data generated in real time can be effectively prevented.
Since the tracking control failure caused by strong vibration or the like can be reliably detected, loss of image data can be prevented in this respect as well.
Since the rotation control mode of the optical disk in the optical disk apparatus 400 can be switched appropriately, image data can be recorded and reproduced at high speed.
Since there is no useless repetition of seek operation and trace operation in the optical disc apparatus 400, image data can be recorded and reproduced at high speed in this respect as well.

As mentioned above, although several embodiment of this invention was described, this invention is not limited only to these, A various change is possible.
For example, at least a part of the processing in the embodiment described above can be realized by a computer and a program. For example, the servo control unit and the system control unit may be realized by dedicated computers, or may be realized by the same computer.

It is a figure which shows an example of a structure of the optical disk apparatus based on embodiment of this invention. 6 is a first flowchart illustrating an example of processing in write access or read access. It is a 2nd flowchart which shows an example of the process in write access or read access. 12 is a third flowchart illustrating an example of processing in write access or read access. It is a 1st flowchart which shows an example of the process at the time of performing a reference position stationary operation. It is a 2nd flowchart which shows an example of the process at the time of performing a reference position stationary operation. It is a flowchart which shows an example of an error cause discrimination | determination process. It is a flowchart which shows an example of a defect error process. It is a figure which shows the structural example of the part which concerns on determination of a tracking error in the optical disk apparatus which concerns on 3rd Embodiment. , It is a figure which shows the example of a waveform of the detection signal of a tracking error in the case where a strong vibration is applied, or when the optical disk has a defect. It is a figure which shows an example of the relationship between the irradiation position of the laser beam from the center of an optical disk, and the rotational speed of an optical disk in the optical disk apparatus which concerns on 4th Embodiment. It is a figure which shows an example of the seek operation | movement in a general optical disk apparatus. It is a 1st figure which shows an example of the seek operation | movement in the optical disk apparatus which concerns on 5th Embodiment. It is the 2nd figure showing an example of the seek operation in the optical disc device concerning a 5th embodiment. It is a block diagram which shows an example of a structure of the imaging device which concerns on 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Interface part, 2 ... FIFO part, 3 ... Data processing part, 4 ... Write processing part, 5 ... Optical pick-up, 6 ... Power control part, 7 ... Laser diode, 8 ... Optical system, 9 ... Optical detection part, 10 DESCRIPTION OF SYMBOLS ... RF signal processing part, 11 ... Read-out processing part, 12 ... Skew detection part, 13 ... Vibration detection part, 14 ... Optical pick-up drive part, 15 ... Motor control part, 16 ... Spindle motor, 17 ... Servo control part, 18 ... System control unit, 91, 92... Photodetection element, 100... Imaging unit, 101... Differential amplification unit, 161 to 163 ... Determination unit, 200 ... Image data processing unit, 300 ... Display unit, 400.

Claims (9)

A rotational drive unit for rotationally driving the optical disc;
When accessing the area from the central track to the first track of the optical disk, rotating the optical disk at a constant angular velocity and accessing the area from the first track to the peripheral track of the optical disk A control unit for controlling the rotation driving unit so as to rotate the optical disk at a constant linear velocity;
An optical disc apparatus having The first track is determined in advance based on the rotation performance of the optical disc included in the rotation drive unit and the reading speed from the optical disc.
The optical disc apparatus according to claim 1. When the controller accesses the area from the central track to the first track of the optical disc, the controller rotates the optical disc at a constant angular velocity according to the rotational performance of the optical disc in the rotational drive unit, and When accessing the area from the first track to the peripheral track of the optical disc, the rotational drive unit is controlled so as to rotationally drive the optical disc at a constant linear velocity corresponding to the reading speed from the optical disc.
The optical disc apparatus according to claim 1. An optical disc apparatus for irradiating light along an information track formed on an optical disc,
A rotational drive unit for rotationally driving the optical disc;
When the irradiation position of the light is in a region closer to the center than the first track of the optical disk, the rotation driving unit is controlled so that the rotation speed of the optical disk is constant, and the irradiation position is set to the first track. A control unit that controls the rotation driving unit so that the irradiation position moves on the information track at a constant speed when in the more peripheral region;
An optical disc apparatus having An optical pickup that converts the reflected light from the optical disc with respect to the irradiation light into an electrical signal and outputs the electrical signal;
A signal processing unit for processing an output signal of the optical pickup;
Have
When controlling the rotation speed of the optical disc to be constant, the control section controls the rotation drive section so that the rotation speed becomes a predetermined upper limit rotation speed that can be driven by the rotation drive section, and the information track When the moving speed of the irradiation position of the light is controlled to be constant, the rotation driving unit is controlled so that the frequency of the output signal of the optical pickup becomes a predetermined upper limit frequency that can be processed by the signal processing unit. ,
The optical disc apparatus according to claim 4. An optical disc control method for controlling rotation of an optical disc,
When accessing the area from the central track to the first track of the optical disk, the optical disk is rotated at a constant angular velocity,
When accessing the area from the first track to the track on the periphery of the optical disc, the optical disc is rotated at a constant linear velocity.
Optical disk control method. The first track is determined based on the rotation performance of the optical disc included in the rotation drive unit of the optical disc and the reading speed from the optical disc.
The optical disk control method according to claim 6. When accessing the area from the central track to the first track of the optical disc, the optical disc is rotationally driven at a constant angular velocity according to the rotational performance of the optical disc in the rotational drive portion of the optical disc,
When accessing the area from the first track to the peripheral track of the optical disc, the optical disc is rotated at a constant linear velocity according to the reading speed from the optical disc.
The optical disk control method according to claim 6. An imaging apparatus having an optical disk device for recording captured image data on an optical disk,
The optical disc apparatus is
A rotational drive unit for rotationally driving the optical disc;
When accessing the area from the central track to the first track of the optical disk, rotating the optical disk at a constant angular velocity and accessing the area from the first track to the peripheral track of the optical disk A control unit that controls the rotation driving unit so as to rotate the optical disk at a constant linear velocity.
Shooting device.

Images