JP2006040413A - Optical disk device and its access control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably perform the high-speed access of the inter-layer movement of an optical disk. <P>SOLUTION: The address difference information of tracks before and after the inter-layer movement is obtained beforehand and held in an address difference value calculation circuit 19, and a focus drive signal level before and after the inter-layer movement at a prescribed position inside the optical disk is obtained beforehand and held in a focus drive signal level holding circuit 18. In an actual operation, a thread logic control signal generation circuit 20 obtains a target address after the inter-layer movement on the basis of the address difference information, and outputs thread drive signals. A jump operation control circuit 16 outputs drive information so as to perform tracking servo corresponding to the target address by position information or the like from a control circuit 17 and the thread drive signals and to perform corresponding focus servo by obtaining a target focus drive signal level at a request address after the inter-layer movement on the basis of the held focus drive signal level. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus and an access control method thereof, and more particularly to an access control method for simultaneously performing tracking servo and focus servo in an optical disc driver and an optical disc apparatus including an optical disc driver for executing the access control method.

  First, a playback control method for the optical disc apparatus will be described. In an optical disk device, a CD-DA (Compact Disc-Digital Audio), a CD-ROM (CD-Read Only Memory), a DVD-ROM (Digital Versatile Disc-ROM), a DVD-R / RW (DVD-Recordable / ReWritable), A recording surface on a disc such as a DVD + R / RW is irradiated with a laser beam from an optical pickup, and the reflected information is detected to read the recorded information.

  When reading information, the optical disc device performs servo control such as focus servo that keeps the distance between the recording surface of the disc and the optical pickup constant, and tracking servo that correctly traces the recorded rows (hereinafter referred to as tracks). Do. In addition, when tracing is performed on a track on the entire surface of the disk, tracing cannot be performed within the operating range of only the optical pickup, and therefore, control is performed to move the entire stage on which the optical pickup is mounted. This control is performed by a thread drive signal (hereinafter referred to as an SD signal).

  Focus servo is a servo that keeps the distance constant when the disk rotates in a state where the distance between the recording surface and the lens is not constant due to manufacturing accuracy of the recording surface, distortion of the disk, etc. (hereinafter referred to as surface blurring). . A specific servo method is to detect a focus error signal (referred to as FE signal) indicating the amount of laser beam defocus from the recording surface, and to change the vertical position of the optical pickup with respect to the recording surface. .

  In reproducing a disc having a plurality of recording surfaces (hereinafter, each recording surface is referred to as a layer), it is necessary to move between the recording surfaces (hereinafter referred to as movement between layers). In that case, the recording surface currently performing the focus servo is switched to the focus servo on another recording surface. This is called focus jump.

  In addition, when reading data in a non-continuous area in one layer, the tracking servo is temporarily stopped, and control is performed to jump over the track to the position where the next reproduction is performed. This is called track jump. At this time, every time a track is crossed, a tracking error signal (hereinafter referred to as a TE signal) indicating that the laser beam is off the track is generated. Therefore, the amount of movement in the layer can be known by counting the TE signal. Can do. In addition, when the track jumps, the operation of moving the entire light receiving unit in the direction perpendicular to the track in the layer is called a seek operation.

  The control based on the SD signal differs depending on the type of mechanical unit that is actually used and includes a spindle motor, a thread feed motor, and an optical pickup. If the mechanical unit is compatible with the stepping operation, the movement of the sled is determined by how many pulses from the distance on the disk to move and the distance moved by one pulse of the stepping control signal without counting the TE signal. If it outputs, it can be controlled by knowing whether it can move to the target position. In addition, an additional circuit is attached to the gear portion of the thread feed motor, a pulse signal is output every time the thread moves a certain distance (each time the gear advances), and the number of pulses of the generated signal is counted, thereby There is also a sled position sensor that performs movement control. As in these two examples, the one that performs thread movement without counting the number of tracks by the TE signal is called a thread logical movement control function, and description will be made based on this function.

  FIG. 9 is a block diagram showing a configuration of an optical disc apparatus that performs focus jump and track jump. The optical pickup 202 irradiates the optical disc 201 with the laser light 301 and generates a data signal 407 and an error signal 409 from the reflected light 302 of the laser light 301. The binarization circuit 204 outputs address data 411 based on the data signal 407. Further, the driver drive signal generation circuit 205 receives the error signal 409 and generates each drive signal (focus drive signal 403, tracking drive signal 404, spindle drive signal 405, and sled drive signal 406) for reading the disk data. I do. These drive signals are input to the driver 203.

  The driver 203 outputs an actuator control signal 402 and a thread control signal 408 to the optical pickup 202 and outputs a disk rotation control signal 401 to the optical disk 201 to control the optical disk 201. When performing a track jump or a focus jump, the control circuit 207 calculates the number of tracks that need to be moved from the address data 411 and the access target data, and jumps to specify a jump operation that matches the calculated number of tracks. The operation designation information 412 is output to the jump operation control circuit 206. In the jump operation control circuit 206, the drive signal designation information 410 is given to the driver drive signal generation circuit 205 in accordance with the jump operation designation information 412, and the driver drive signal generation circuit 205 previously described in accordance with the drive signal designation information 410. The jump operation is executed by controlling each drive signal.

  FIG. 10 is a flowchart relating to an access operation including inter-layer movement. When an access request including inter-layer movement is issued to the optical disc apparatus, the optical disc apparatus first determines whether the movement target address exists in layer 0 or layer 1 (step S101). Next, it is determined whether or not the layer of the target address matches the layer currently performing the tracking operation (step S102). If they do not match, the layer 0 to the layer 1 (or its On the contrary, a focus jump for moving between layers is executed (step S108), and the process returns to step S102. If they match (the operation ends normally), the currently read address information is acquired (step S103). The number of moving tracks from the acquired address to the requested target address is calculated (step S104), and an SD signal, which is a track jump control signal in accordance with the thread control method, is generated (step S105). This is performed (step S106). After executing the track jump, the address information is obtained again, and it is determined whether or not the target address has been reached (step S107), and the process returns to step S103 and repeats the track jump until the target address is reached.

  As described above, in the access control including the movement between layers, the two operations of the focus jump and the track jump are separately performed until the target address is reached. Therefore, there is a problem that it takes an access time to reach the target address. Therefore, for the purpose of speeding up access, a technique for simultaneously executing two operations of a focus jump and a track jump in parallel is disclosed in Patent Documents 1, 2, 3, and the like.

JP 2002-8252 A (FIGS. 1 and 2) Japanese Patent Laid-Open No. 9-219028 (FIGS. 1 and 2) JP-A-10-162373 (FIGS. 1 and 4)

  The conventional optical disc apparatus is configured to execute two operations of focus jump and track jump at the same time. However, when surface blurring is large, the operation of the focus drive signal (hereinafter referred to as FD signal) for driving the lens in the focus direction may be kept constant, and the operation may not be stable even if a focus jump is performed. There is a possibility that the access time increases and the playback operation after access becomes unstable. Furthermore, there is a problem that the surface blur becomes larger during the high-speed rotation of the disc, and the stability of the focus jump is also lowered.

  Accordingly, an object of the present invention is to provide an optical disc apparatus and its access control method that stably realize high-speed access including inter-layer movement, which is compatible with high-speed rotation of an optical disc.

  The optical disk apparatus according to the first aspect of the present invention that achieves the above object is an optical disk apparatus that performs tracking servo and focus servo in parallel when the optical disk moves between layers. This optical disc apparatus includes an address difference information holding unit that obtains and holds address difference information of a track before and after movement between layers on an optical disc in advance of an actual operation, and a focus drive signal level before and after movement between layers at a predetermined position in the optical disc. And a focus drive signal level holding unit that obtains and holds the above in advance prior to actual operation. Also, the address calculation unit that obtains the target address for the requested address of the track after movement between layers in the actual operation based on the address difference information held in the address difference information holding unit, and the focus drive signal level holding unit A level calculation unit that obtains a target focus drive signal level at a requested address after movement between layers in actual operation based on a focus drive signal level that is present. Tracking servo is performed corresponding to the target address obtained by the address calculating unit, and focus servo is performed corresponding to the target focus drive signal level obtained by the level calculating unit.

  An optical disc apparatus according to a second aspect of the present invention includes an address difference value calculation circuit that obtains and holds address difference information of a track before and after movement between layers on an optical disc in advance prior to actual operation, and a layer at a predetermined position in the optical disc. A focus drive signal level holding circuit that obtains and holds the focus drive signal level before and after the movement in advance prior to the actual operation. If the access request address is given in the actual operation, the target address for the track request address after the movement between layers in the actual operation is obtained based on the address difference information held in the address holding circuit difference value calculation circuit. A thread logic control signal generation circuit for outputting a thread driving signal. Further, the tracking servo corresponding to the target address is performed by the thread drive signal output from the thread logic control signal generation circuit, and in the actual operation based on the focus drive signal level held in the focus drive signal level holding circuit. A jump operation control circuit for obtaining a target focus drive signal level at a requested address after movement between layers and outputting drive information to a driver drive signal generation circuit so as to perform focus servo corresponding to the target focus drive signal level; and jump operation A driver drive signal generation circuit for controlling the optical disc driver to perform tracking servo and focus servo in parallel based on drive information output from the control circuit.

  In the optical disk device of the first development form, the predetermined position in the optical disk may include an outermost track position and an innermost track position of the optical disk.

  In the optical disk device of the second development form, the focus drive signal level holding circuit obtains the maximum value and the minimum value in the focus drive signal level obtained a predetermined number of times in accordance with the rotation of the disk, and obtains it from the maximum value and the minimum value. The jump operation control circuit may obtain the target focus drive signal level based on the average value.

  In the optical disk apparatus according to the third development form, the jump operation control circuit is configured to generate a target focus at a requested address from two average values obtained at the outermost track position, the intermediate track position, and the innermost track position of the optical disk. You may obtain | require by the calculation which interpolates a drive signal level.

  In the optical disk device of the fourth development form, the address difference value calculation circuit corrects the address change amount serving as a reference when moving between layers based on the rotation speed data of the disk in actual operation so as to obtain address difference information. It may be configured.

  In the optical disk device of the fifth development form, the thread logic control signal generation circuit predicts the predicted address value after the layer movement from the address difference information and the current position address data in the actual operation, and calculates the number of moving tracks from the predicted address value. It may be configured to obtain the target address.

  In the optical disk apparatus according to the sixth development form, the jump operation control circuit may correct the target focus drive signal level when a predetermined error signal cannot be detected when performing focus servo.

  The access control method of the optical disc apparatus according to the third aspect of the present invention is a method of performing tracking servo and focus servo in parallel when the optical disc moves between layers. In this method, the track address difference information before and after movement between layers on the optical disc is obtained and held in advance prior to the actual operation, and the focus drive signal level before and after movement between layers at a predetermined position in the optical disc is obtained prior to the actual operation. And obtaining and holding in advance. Further, a step of obtaining a target address for a track requested address after movement between layers in actual operation based on the held address difference information, and after movement between layers in actual operation based on the held focus drive signal level Determining a target focus drive signal level at the requested address. And a step of controlling the driving of the optical disc so that the tracking servo corresponding to the target address and the focus servo corresponding to the target focus drive signal level are performed in parallel.

  In the access control method for the optical disk device according to the first development mode, the predetermined position in the optical disk may include the outermost track position and the innermost track position of the optical disk.

  In the access control method of the optical disk apparatus of the second development form, in the step of obtaining and holding the focus drive signal level in advance prior to the actual operation, the maximum of the focus drive signal levels acquired a predetermined number of times according to the rotation of the disk In the step of obtaining the value and the minimum value and holding the average value obtained from the maximum value and the minimum value, and obtaining the target focus drive signal level, the target focus drive signal level may be obtained based on the average value. .

  In the access control method for the optical disc apparatus of the third development mode, in the step of obtaining the target focus drive signal level, two of the average values obtained at the outermost track position, the intermediate track position, and the innermost track position of the optical disc are obtained. You may obtain | require by the calculation which interpolates the target focus drive signal level in a request address from an average value.

  In the access control method for the optical disk apparatus according to the fourth development mode, in the step of obtaining the target address, the address change information which is corrected based on the rotational speed data of the disk in the actual operation is corrected based on the amount of change in address serving as a reference when moving between layers. May be obtained.

  In the access control method of the optical disk apparatus of the fifth development mode, in the step of obtaining the target address, the predicted address value after the layer movement is predicted from the address difference information and the current position address data in the actual operation, and moved from the predicted address value. The number of tracks may be obtained and used as a target address.

  In the access control method of the optical disk apparatus according to the sixth development mode, in the step of controlling the driving of the optical disk, if a predetermined error signal cannot be detected when performing the focus servo, the target focus drive signal level is corrected. May be.

  According to the present invention, the FD signal levels of different layers are stored in advance, and the close point is detected from the vicinity of the focus close point with reference to the stored value, so that the driving distance of the optical pickup can be reduced. In addition, by holding the predicted address position after layer movement in advance and referring to this, thread movement is performed before the movement between layers is completed, and the movement between layers and thread movement are performed almost simultaneously. The access time can be shortened. Therefore, high-speed access including inter-layer movement is stably realized.

  An optical disc apparatus according to an embodiment of the present invention includes an address difference value calculation circuit (19 in FIG. 1) that preliminarily obtains and holds track address difference information before and after movement between layers in an optical disc, A focus drive signal level holding circuit (18 in FIG. 1) that obtains and holds the focus drive signal level before and after the movement between layers at a predetermined position in advance before the actual operation; If an access request address is given in actual operation, the thread logic control signal generation circuit (20 in FIG. 1) adds the address difference information held in the address holding circuit difference value calculation circuit (19 in FIG. 1) to the address difference information. Based on this, the target address for the requested address of the track after movement between layers in the actual operation is obtained, and a thread drive signal is output. The jump operation control circuit (16 in FIG. 1) determines the target address based on the position information from the control circuit (17 in FIG. 1) and the thread drive signal output from the thread logic control signal generation circuit (20 in FIG. 1). The drive information is output to the driver drive signal generation circuit (15 in FIG. 1) so as to perform the tracking servo corresponding to. At the same time, the jump operation control circuit (16 in FIG. 1) uses the requested address after movement between layers in the actual operation based on the focus drive signal level held in the focus drive signal level holding circuit (18 in FIG. 1). A target focus drive signal level is obtained, and drive information is output to the driver drive signal generation circuit (15 in FIG. 1) so as to perform focus servo corresponding to the target focus drive signal level. The driver drive signal generation circuit (15 in FIG. 1) performs two controls of the tracking servo and the focus servo in parallel on the optical disk driver (13 in FIG. 1) based on the drive information.

  FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention. In FIG. 1, the optical disk 11, optical pickup 12, driver 13, binarization circuit 14, and driver drive signal generation circuit 15 are the optical disk 201, optical pickup 202, driver 203, binarization circuit 204, driver of FIG. This corresponds to the drive signal generation circuit 205, and a description thereof is omitted. The jump operation control circuit 16 and the control circuit 17 correspond to the jump operation control circuit 206 and the control circuit 207, respectively, but the control operation is different from the input / output of the control signal. In the following, the FD signal level holding circuit 18, the inter-layer movement address difference value calculation circuit 19, and the thread logic control signal generation circuit 20 that are newly added to FIG.

  First, the FD signal level holding circuit 18 will be described. FIG. 2 is a block diagram showing a configuration of the FD signal level holding circuit. In FIG. 2, the FD signal level holding circuit 18 includes a filter 30, a calculator 31, a buffer 32, and a timing generation unit 33. The filter 30 receives a focus error signal (FE signal) 113 in the error signal 109 output from the optical pickup 12 in a state where the focus servo is applied, and serves as a base for controlling the focal direction of the optical pickup. A drive signal (FD signal) 114 is generated and output to the computing unit 31. The timing generator 33 receives the disk rotation frequency signal (FG signal) 116 from the driver 13, counts the period of the FG signal 116, and outputs a data latch signal 117 to the calculator 31 for each disk rotation.

  The computing unit 31 receives the focus drive signal 114 and the data latch signal 117, acquires the level of the focus drive signal 114 based on the data latch signal 117 for an arbitrary designated number of times, and acquires the maximum value and minimum value of the acquired data. Is obtained and output to the buffer 32 as a focus drive signal maximum value / minimum value level (FDRVA signal) 115. In each of layer 0 and layer 1, the buffer 32 is located near the innermost circumference (data address A shown in FIG. 7), near the middle (data address B shown in FIG. 7), and near the outermost circumference (FIG. 7). The focus drive signal maximum value / minimum value level (FDRVA signal) 115 at each position acquired at three positions of the data address C) shown in FIG. The held data is output to the jump operation control circuit 16 as FD signal level data (FOLD signal) 118 including surface blur correction.

  Next, the address difference value calculation circuit 19 during movement between layers will be described. FIG. 3 is a block diagram showing a configuration of an address difference value calculation circuit during movement between layers. In FIG. 3, the inter-layer movement address difference value calculation circuit 19 includes selectors 40 and 46, frequency counters 41 and 43, a frequency comparator 42, an inter-layer address movement value calculation circuit 44, a buffer 45, a difference calculation circuit 47, a reference. A speed address movement value calculation circuit 48 is provided.

  The selector 40 receives the FG signal 116 from the driver 13 and outputs it to the frequency counter 43 as the reference speed FG signal 122 in a state where the optical pickup 12 properly follows the address data. The frequency counter 43 obtains the reference rotation speed data 123 by counting the input reference speed FG signal 122 and outputs it to the frequency comparator 42 and the reference speed address movement value calculation circuit 48.

  Furthermore, the operation when the focus jump is executed in this state and the access operation from layer 0 to layer 1 and from layer 1 to layer 0 (which layer information is retained is switched by the selector 46) is performed. The acquisition address data immediately before the start and the first address data (layer 0 address data 126 and layer 1 address data 127) that can be normally acquired after the operation is executed are output to the difference calculation circuit 47.

  The difference calculation circuit 47 calculates an address difference when the focus jump from layer 0 to layer 1 is performed and outputs the difference as address difference data (layer 0-1 address difference data 128) to the reference speed address movement value calculation circuit 48. . Further, when the focus jump from layer 1 to layer 0 is performed, the same calculation is performed as address difference data (layer 1-0 address difference data 129), which is output to the reference speed address movement value calculation circuit 48.

  When the focus jump is executed, the reference speed address movement value calculation circuit 48 calculates the amount of change in the address before and after the movement between layers, and the address at the time of movement between the reference layers in the reference rotation speed data 123 The amount of change is held in a buffer in the reference speed address movement value calculation circuit 48.

  On the other hand, at the time of access execution, the selector 40 takes in the FG signal 116 at the time of access execution and outputs it to the frequency counter 41 as the FG signal 119 at the time of access execution. The frequency counter 41 counts the access execution time FG signal 119 to acquire the access execution speed data 120 and outputs it to the frequency comparator 42. The frequency comparator 42 calculates the speed ratio data 121 between the reference speed and the speed at the time of access from the access execution speed data 120 and the reference speed data 123 and outputs it to the inter-layer address movement value calculation circuit 44. To do. The inter-layer address movement value calculation circuit 44 corrects the data of the reference address movement address change amount 130 output from the reference speed address movement value calculation circuit 48 based on the input speed ratio data 121, so that the inter-layer address movement at the time of access execution is corrected. The moving address change amount 124 is calculated and output to the buffer 45. The buffer 45 holds the inter-layer moving address change amount 124 and outputs it to the thread logic control signal generation circuit 20 as the address change value 125.

  Next, the thread logic control signal generation circuit 20 will be described. FIG. 4 is a block diagram showing the configuration of the thread logic control signal generation circuit. As shown in FIG. 4, the thread logic control signal generation circuit 20 includes a difference calculation circuit 50, a moving track number calculation circuit 51, and a thread operation control signal generation circuit 52. A control circuit (system controller) 17 for controlling the optical disk system outputs the current position address data 133 of the disk read from the disk 11 and read by the optical pickup 12 to the difference calculation circuit 50, so that the address data of the access target is obtained. The data 132 and the type information 131 of the disc to be used are output to the moving track number calculation circuit 51.

  The difference calculation circuit 50 receives the address change value 125 and the current position address data 133 output from the buffer 45 in FIG. 3, calculates the post-layer movement address prediction value 134, and outputs it to the moving track number calculation circuit 51. The moving track number calculating circuit 51 matches the disc pitch information, the disk radius, the sector frequency, the linear velocity, etc., recorded in the moving track number calculating circuit 51 with the disc type information 131 input from the control circuit 17. From the predicted address value 134 and the access target address data 132, the moving track number 135 from the address after the layer movement to the access target address is calculated from the address predicted value 134 and the access target address data 132. Output. The thread operation control signal generation circuit 52 generates a thread drive signal 136 from the input moving track number 135 and outputs it to the jump operation control circuit 16. It is assumed that the thread operation control signal generation circuit 52 generates the thread drive signal 136 in accordance with the mechanical unit actually used. That is, when the mechanical unit has a thread logical movement control function, the circuit configuration is adapted to the thread logical movement control function.

  The jump operation control circuit 16 outputs FD signal level data (FOLD signal) 118 output from the FD signal level holding circuit 18, jump operation designation information 112 output from the control circuit 17, and output from the thread logic control signal generation circuit 20. Thread drive signal 136 is input, drive signal designation information 110 is generated based on these input signals, and output to driver drive signal generation circuit 15. The driver drive signal generation circuit 15 generates various drive signals for servo control (focus drive signal 103, tracking drive signal 104, spindle drive signal 105, thread drive signal 106) from the error signal 109 and drive signal designation information 110. To the driver 13 to control access to the disk.

  Next, the operation of the optical disk apparatus configured as described above will be described. The thread logical movement control function will be described below assuming that a stepping operation is performed.

  In order to enable the functions of the present embodiment using the optical disk device according to the present embodiment, first, the optical disk device is operated so as to acquire necessary information immediately before the access operation permission state for the disk is entered. Let First, when adjusting a signal such as a focus error or a tracking error with respect to the disk, the FD signal level holding circuit 18 is in a state where the focus servo is applied at the layer 0 (data address A in FIG. 7). , B, C), the maximum value and the minimum value of the FD signal level are acquired and held in the buffer 32. When the data holding in layer 0 is completed, a focus jump is made to layer 1 and, similarly, in a state where focus servo is applied in layer 1, a predetermined location on the disk (data addresses A, B, The maximum value and the minimum value of each FD signal level in C) are held in the buffer 32. Further, as will be described later, an average value of the maximum value and the minimum value may be obtained and each average value at a predetermined location may be held.

  Next, the inter-layer movement address difference value calculation circuit 19 acquires the read address information in a state where the address information can be correctly acquired from the disk after the automatic adjustment operation of each signal to the disk is completed. When the acquisition is completed, a focus jump is executed to move between layers, and after the movement is completed, the first address information that has been successfully acquired is retained. In addition, by acquiring the FG signal 116 at the time of executing the movement between the layers and obtaining the disk rotation number, the movement address change amount 124 between layers when the focus jump is executed at a certain speed (reference speed) is obtained. To do. Thereafter, the movement between layers is performed again, and similar information (address information before and after execution of focus jump) is acquired. That is, the inter-layer movement address change amount 124 is obtained for both the case where the inter-layer movement from the layer 1 to the layer 0 and the case where the inter-layer movement from the layer 0 to the layer 1 is performed. Keep it.

  Servo in the operation at the time of an actual access request based on the FD signal levels of layer 0 and layer 1 held in the buffer 32 and the address difference value (inter-layer moving address change amount 124) held in the buffer 45 Control is performed. This control will be described below.

  When an access request including movement between layers is generated in the optical disk device, the current position address data 133 currently read from the control circuit 17, the target address data 132 of the access target, and the type of the disk that is being controlled ( Used disk information 131 indicating the disk type (CD, DVD, DVD + R, etc.) is input to the thread logic control signal generation circuit 20, and the access operation process is started. In the access operation process, focus control and thread control are executed simultaneously.

  First, the operation on the focus control side will be described. FIG. 5 is a flowchart showing the operation on the focus control side. When access control is started, the maximum value and minimum value of the FD signal level held in the buffer 32 are used, and the average value of the FD signal level near the target address is always output (signal hold) (step S11). .

  Here, a method of calculating the average value of the FD signal level will be described. In the calculation, the FD signal level is acquired at each of positions A, B, and C on the disc shown in FIG. Here, address A is the innermost area where data exists, that is, near the beginning of data in the disk, address B is near the middle of the area where data exists, and address C is the area where data exists. The outermost of the data, ie, near the end of the data in the disk.

  Assuming that the maximum value of the FD signal acquired at address A is FDmaxA and the minimum value is FDminA, the average value FDavA is FDavA = (FDminA + FDmaxA) / 2. When the maximum value of the FD signal acquired at address B is FDmaxB and the minimum value is FDminB, the average value FDavB is FDavB = (FDminB + FDmaxB) / 2. Further, if the maximum value of the FD signal acquired at address C is FDmaxC and the minimum value is FDminC, the average value FDavC is FDavC = (FDminC + FDmaxC) / 2.

  Now, assuming that the target address is T, the average value FDAve of the FD signal level near the target address T in accordance with the request address is calculated as follows.

  1. When the requested address is between address A and address B and (1-1) FDavA is larger than FDavB, the predicted change FDpreAB of the FD signal when the address changes by one sector is FDpreAB = (FDavA −FDavB) / (B−A), and based on this value, FDAve is obtained as FDAve = FDavA− {FDpreAB × (TA)}. (1-2) When FDavB is larger than FDavA, the change predicted value FDpreBA of the FD signal when the address changes by one sector is FDpreBA = (FDavB−FDavA) / (B−A), and FDAve is It is calculated as FDAve = FDavA + {FDpreBA × (T−A)}.

  2. If the requested address is between address B and address C: The FD signal change predicted values FDpreBC and FDpreCB when the address changes by one sector are calculated by the same procedure as described above, and FDAve is calculated. (2-1) When FDavB is larger than FDavC, FDpreBC = (FDavB−FDavC) / (C−B), and FDAve = FDavB− {FDpreBC × (T−B)} is obtained. (2-2) When FDavC is larger than FDavB, FDpreCB = (FDavC−FDavB) / (C−B), and FDAve = FDavB + {FDpreCB × (T−B)} is obtained.

  As described above, after outputting the average value of the FD signal level, the FE signal is monitored in the same manner as in the normal focus jump (step S12).

  During this time, since the sled is moving, the movement across the track on the disc is performed. At that time, the disc has surface blurring, and the level of the FE signal 113 constantly changes. become. As a condition for the end of the focus jump, as shown in FIG. 8, a level (FALV-H signal 151 or FALV-L signal 152) at which the S-shaped amplitude of the FE signal 113 is set is detected, and then the zero cross 150 is set. Is to detect. When the thread moves, the FE signal constantly changes due to surface blurring means that an S-shaped amplitude is generated. After detecting a certain setting level after moving the layer, detection of the zero cross of the FE signal. (Hereinafter referred to as a focus close point). Further, when detecting the focus close point, it can be determined which of the layer 0 and the layer 1 has been moved based on the detection direction of the S-shaped amplitude, so that it is understood that the target layer has been detected (step S13). ).

  If the target layer is detected in step S13, the FD signal hold output is stopped and switched to the normal focus servo follow-up operation (step S14), and the series of operations ends.

  On the other hand, if the target S-shaped amplitude cannot be detected for a specified number of times (can be arbitrarily specified from the control circuit), the level of the output FD signal is varied. As a variable rate, in the case of moving to layer 1, for example, 10% of the difference between the maximum value and the minimum value of the held FD signal level is added to the level of the currently output FD signal, In the case of moving to layer 0, for example, 10% of the difference between the maximum value and the minimum value is subtracted and an FD signal is output (step S15).

  The operation state on the thread side is determined at the timing of switching the FD signal output (step S16). If the operation on the thread side is not completed, the process returns to step S13 to detect the S-shape amplitude again, and the target layer Continue detection. When the operation on the thread side is completed, the focus jump operation is executed from the current output level, and the movement between layers is performed (step S17). It is determined whether or not the target layer has been reached (step S18). If it has not been reached, the process returns to step S17. Also in this case, since the focus jump operation is performed based on the held FD signal level, it is possible to perform a stable jump operation in consideration of surface blurring.

  Next, the thread-side control performed simultaneously with the focus operation described above will be described. FIG. 6 is a flowchart showing the operation on the thread control side.

  The thread logic control signal generation circuit 20 generates the thread drive signal 136 based on the address information input by the control circuit 17 and the inter-layer address difference information held in the inter-layer movement address difference value calculation circuit 19. Generate. In this case, the inter-layer movement address difference value calculation circuit 19 acquires the FG signal 116 at the time of access execution, corrects the inter-layer movement address change amount 124 held in the buffer 45, and addresses at the time of access execution. A change value 125 is calculated. This address change value 125 is input to the thread logic control signal generation circuit 20, and the moving track number 135 is calculated. In this operation example, the mechanical unit performs a stepping operation, and therefore generates a thread movement pulse signal based on the calculated number of movement tracks. Then, the sled is moved using the sled moving pulse signal (step S21). When the thread movement is completed (YES in step S22), it is determined whether or not the focus side control operation has been completed, and the control waits for the focus side control to end (step S23).

  After the control operation on the focus side is completed, the current address is acquired (step S24), it is determined whether or not the target address has been reached (step S25), and if the target address has been reached, The access operation is terminated. On the other hand, if the target address has not been reached, a track jump operation or the like is performed (step S26), and control is returned to step S25 to move to the target address.

  As described above, the disk access control of this embodiment holds the FD signal levels of layer 0 and layer 1 in advance, and detects the close point from the vicinity of the focus close point with reference to the value, so that the optical pickup The driving distance is small. In addition, since the address predicted position after the layer movement is held in advance and the thread movement can be executed before the movement between layers is completed by referring to this, by performing the movement between layers and the thread movement almost simultaneously, The access time can be shortened.

  As a modification of the embodiment of the present invention, the basic configuration is as described above, but each of the FD signal level holding circuit 18, the inter-layer movement address difference value calculation circuit 19, and the thread logic control signal generation circuit 20 includes: A configuration may be adopted in which data after execution of the access operation is input, and the stored data is corrected with the input value. That is, in this case, after the access control, it is necessary to acquire the data described above. With such a configuration, a learning function is added to this function, and the access time can be further shortened.

It is a block diagram which shows the structure of the optical disk apparatus based on the Example of this invention. It is a block diagram which shows the structure of a FD signal level holding circuit. It is a block diagram which shows the structure of the address difference value calculation circuit at the time of the movement between layers. It is a block diagram which shows the structure of a thread | sled logic control signal generation circuit. It is a flowchart showing operation | movement by the focus control side. It is a flowchart showing the operation | movement by the thread | sled control side. It is a figure showing the acquisition position of the focus drive signal level on a disc. It is a figure showing S character amplitude of a focus error signal. It is a block diagram which shows the structure of the optical disk apparatus which performs the conventional focus jump and track jump. It is a flowchart figure which concerns on the access operation containing the movement between the conventional layers.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Optical disk 12 Optical pick-up 13 Driver 14 Binary circuit 15 Driver drive signal generation circuit 16 Jump operation control circuit 17 Control circuit 18 FD signal level holding circuit 19 Inter-layer movement address difference value calculation circuit 20 Thread logic control signal generation circuit 30 Filter 31 Calculator 32, 45 Buffer 33 Timing generator 40, 46 Selector 41, 43 Frequency counter 42 Frequency comparator 44 Inter-layer address movement value calculation circuit 47 Difference calculation circuit 48 Reference speed address movement value calculation circuit 50 Difference calculation circuit 51 Number of moving tracks calculation circuit 52 Thread operation control signal generation circuit 101 Disk rotation control signal 102 Actuator control signal 103 Focus drive signal (FD signal)
104 Tracking drive signal (TD signal)
105 Spindle drive signal (MD signal)
106 Thread drive signal (SD signal)
107 Data signal 108 Thread control signal 109 Error signal 110 Drive signal designation information 111 Address data 112 Jump operation designation information 113 Focus error signal (FE signal)
114 Focus drive signal (FD signal)
115 Focus drive signal maximum / minimum level 116 Disc rotation frequency signal (FG signal)
117 Data latch signal 118 FD signal level data (FDLD signal)
119 Access execution FG signal 120 Access execution rotation speed data 121 Speed ratio data 122 Reference speed FG signal 123 Reference rotation speed data 124 Inter-layer movement address change 125 Address change value 126 Layer 0 address data 127 Layer 1 address data 128 Layer 0-1 address difference data 129 Layer 1-0 address difference data 130 Reference layer moving address change amount 131 Used disk information 132 Target address data 133 Current position address data 134 Post-moving address prediction value 135 Number of moving tracks 136 Thread drive Signal 150 Zero cross 151 FALV-H signal 152 FALV-L signal

Claims (15)

In an optical disc apparatus that performs tracking servo and focus servo in parallel when moving between layers of an optical disc,
An address difference information holding unit for obtaining and holding in advance the address difference information of the track before and after the movement between layers in the optical disc;
A focus drive signal level holding unit that obtains and holds in advance a focus drive signal level before and after the movement between layers at a predetermined position in the optical disc;
An address calculation unit for obtaining a target address for a request address of a track after movement between layers in the actual operation based on the address difference information held in the address difference information holding unit;
A level calculation unit for obtaining a target focus drive signal level at a request address after movement between layers in the actual operation based on the focus drive signal level held in the focus drive signal level holding unit;
With
The optical disk apparatus according to claim 1, wherein the tracking servo is performed corresponding to the target address obtained by the address calculating unit, and the focus servo is performed corresponding to the target focus drive signal level obtained by the level calculating unit. An address difference value calculation circuit for obtaining and holding address difference information of a track before and after movement between layers on an optical disc in advance of an actual operation;
A focus drive signal level holding circuit for preliminarily obtaining and holding a focus drive signal level before and after movement between layers at a predetermined position in the optical disc;
If an access request address is given in actual operation, a target address for the requested address of the track after movement between layers in actual operation is obtained based on the address difference information held in the address holding circuit difference value calculation circuit. A thread logic control signal generation circuit for outputting a thread driving signal;
Actual operation based on the focus drive signal level held in the focus drive signal level holding circuit so as to perform tracking servo corresponding to the target address by a thread drive signal output from the thread logic control signal generation circuit A jump operation control circuit that obtains a target focus drive signal level at the requested address after movement between layers in the memory and outputs drive information to a driver drive signal generation circuit so as to perform focus servo corresponding to the target focus drive signal level;
The driver drive signal generation circuit that controls the optical disc driver to perform the tracking servo and the focus servo in parallel based on the drive information output from the jump operation control circuit;
An optical disc apparatus comprising:   3. The optical disk apparatus according to claim 1, wherein the predetermined position in the optical disk includes an outermost track position and an innermost track position of the optical disk. The focus drive signal level holding circuit obtains the maximum value and the minimum value in the focus drive signal level acquired a predetermined number of times in accordance with the rotation of the disk, and holds the average value obtained from the maximum value and the minimum value. Composed of
3. The optical disc apparatus according to claim 2, wherein the jump operation control circuit obtains the target focus drive signal level based on the average value.   The jump operation control circuit sets the target focus drive signal level at the required address from two average values of the average values obtained at the outermost track position, the intermediate track position, and the innermost track position of the optical disc. 5. The optical disk apparatus according to claim 4, wherein the optical disk apparatus is obtained by calculation to insert.   The address difference value calculating circuit is configured to obtain the address difference information by correcting an address change amount serving as a reference when moving between layers based on the rotational speed data of the disk in the actual operation. The optical disk apparatus according to claim 2.   The thread logic control signal generation circuit predicts an address predicted value after layer movement from the address difference information and the current position address data in the actual operation, obtains the number of moving tracks from the address predicted value, and calculates the target address and The optical disc apparatus according to claim 2, wherein the optical disc apparatus is configured to do so.   3. The optical disc apparatus according to claim 2, wherein the jump operation control circuit corrects the target focus drive signal level when a predetermined error signal cannot be detected during the focus servo. An access control method for an optical disc apparatus that performs tracking servo and focus servo in parallel when moving between layers of an optical disc,
Obtaining and holding the address difference information of the track before and after the movement between layers in the optical disc prior to the actual operation;
Pre-determining and holding the focus drive signal level before and after the movement between layers at a predetermined position in the optical disc; and
Obtaining a target address for a request address of a track after movement between layers in actual operation based on the held address difference information;
Obtaining a target focus drive signal level at a request address after movement between layers in the actual operation based on the held focus drive signal level;
Controlling the driving of the optical disc to perform in parallel a tracking servo corresponding to the target address and a focus servo corresponding to the target focus drive signal level;
An access control method for an optical disc apparatus, comprising:   10. The access control method for an optical disk device according to claim 9, wherein the predetermined position in the optical disk includes an outermost track position and an innermost track position of the optical disk. In the step of obtaining and holding the focus drive signal level in advance prior to actual operation, the maximum value and the minimum value in the focus drive signal level acquired a predetermined number of times in accordance with the rotation of the disk are obtained, and the maximum value and the minimum value are obtained. A step of holding an average value obtained from the values,
10. The access control method for an optical disk device according to claim 9, wherein in the step of obtaining the target focus drive signal level, the target focus drive signal level is obtained based on the average value.   In the step of obtaining the target focus drive signal level, the target focus drive at the requested address is calculated from two average values of the average values obtained at the outermost track position, the intermediate track position and the innermost track position of the optical disc. 12. The access control method for an optical disk device according to claim 11, wherein the signal level is obtained by an operation for interpolating.   10. The address difference information is obtained by correcting an address change amount serving as a reference when moving between layers based on rotational speed data of the disk in the actual operation in the step of obtaining the target address. Access control method for an optical disc apparatus.   In the step of obtaining the target address, an address predicted value after layer movement is predicted from the address difference information and current position address data in the actual operation, and the number of moving tracks is determined from the address predicted value to be a target address. 10. The access control method for an optical disc apparatus according to claim 9, 10. The optical disk according to claim 9, wherein, in the step of controlling the driving of the optical disk, if a predetermined error signal cannot be detected when the focus servo is performed, the target focus drive signal level is corrected. Device access control method.

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