JPH11345420A - Focus jump control method and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move to optimum timing even when an optimum jump pulse condition is shifted by adjusting so as to arrive at a target recording layer and so that a speed becomes zero just when a deceleration pulse is ended. SOLUTION: At a data reproducing time, control is applied by a focus control means 7 so that a focus error signal becomes '0', and its output is converted to thrust in the focal direction of an objective lens by a focus drive means 8 and a focus actuator 4, and a feedback control system is constituted, and the objective lens 3 is position controlled. Further, when a focus is moved to another recording layer, a servo controller 11 switches a focus jump control means 9 provided in the inside to a focus control means 7 with a switch 10 to make the focus jump to the target recording layer. Then, the focus jump control means 9 uses a RAM secured in a learning table 13 in the servo controller 11 to learn a wait time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus jump control method for controlling the movement of a laser focus between adjacent recording layers in a layer direction in order to read a plurality of layers of data from one side in an optical disk reproducing apparatus such as a DVD. And an optical disc device therefor.

[0002]

2. Description of the Related Art A focus error signal (hereinafter, referred to as an FE signal) in a two-layer disc is outputted in a form in which an S-shaped waveform is continuous for two periods as shown in FIG. In FIG. 7, points L0 and L1, which are the centers of the two S-characters, indicate the recording surfaces of the respective layers. In the conventional technology, the basic processing for the focus jump is that the focus servo is turned off.
F, an acceleration pulse is applied, a point near the intermediate point is detected, a deceleration pulse is applied, and the focus servo is turned on again. However, unlike the track jump in the track direction, in the focus jump, there are problems such as variations in the interlayer distance and interference of the S-shape of each layer to prevent a clean sine waveform, and the speed becomes zero in the target layer. Such a stable focus jump cannot be performed. For this reason, Japanese Patent Publication No. Hei 8-171731, Japanese Patent Publication No. Hei 9-506
Incorporation of the processing described in Japanese Patent Publication No. 30 has been taken to increase the stability.

An example of a conventional focus jump will be described with reference to FIG. In FIG. 8, when jumping from the L0 point to the L1 point, the jump processing is performed in the following flow from the state where the focus servo is applied at the L0 point. (1) Focus servo OFF (2) Apply acceleration pulse (V1) to point A where FE signal crosses LVL2. (3) Turn off the acceleration pulse. (4) Measure and store the acceleration pulse time at this time.
(T1) (5) After detecting the point B where the FE signal intersects with the LVL1, generate a deceleration pulse that produces twice the acceleration of the acceleration pulse. (6) Apply the pulse assuming that the application time of the deceleration pulse is T1 / 2. And turn on the servo. With such control, the brake pulse (deceleration pulse)
Is completed, the speed of the objective lens becomes 0. Therefore, if the robot has just reached the point L1, a stable jump can be made. Conversely, like that, LVL
1 level needs to be set.

[0004]

However, in the FE signal of the multi-layer optical disk, the reflected light of the layers interferes with each other, so that noise or signal disturbance occurs at the midpoint between the two S-shaped signals, and a clean signal is secured. Can not. Therefore, when detecting the timing of issuing the brake pulse, the level cannot be accurately detected, and a problem arises in that the servo cannot be retracted. Also, circuit offset, local substrate thickness of disk,
A problem arises in that the balance and shape of the FE waveform vary depending on the location of the disk due to variations in the interlayer distance and reflectivity, and similarly, an optimal jump pulse cannot be generated, resulting in an unstable jump.

In such a case, conventionally, it is necessary to adjust the volume or the like so as not to generate an offset so as to correct the circuit, or to improve the characteristics of the pickup so as not to be affected by the disk. Significant increases in time, effort and cost occur. Alternatively, even if the jump pulse is not optimal to some extent, control such as forcibly increasing the gain of the servo is performed, and the current is allowed to flow as much as the power supply voltage allows to secure the pull-in performance. However, the reduction in the sensitivity of the actuator of the pickup due to the miniaturization of the device and the situation in which the power supply voltage must be reduced overlapped, and the maximum acceleration generated by the actuator was reduced, so the servo loop gain was forcibly pulled in. However, there is a problem that the dynamic range is narrow and the possibility of failing in the pull-in is high.

The present invention relates to a case where the balance or waveform shape of the FE signal is distorted due to such a local change in the characteristics of the disk or a variation in the characteristics of the pickup, and when the maximum acceleration generated by the actuator is small. However, it is an object of the present invention to provide a focus jump control method and an optical disk device that can perform a focus jump stably.

[0007]

In order to achieve the above object, an optical disk apparatus of the present invention measures the level of a focus error signal at the end of a deceleration pulse and determines whether the jump timing is optimal based on the value. Judgment is made, and the result is the time from the acceleration pulse to the deceleration pulse, the pulse height of the acceleration pulse and the deceleration pulse, or the application time of the acceleration pulse and the deceleration pulse, or the acceleration pulse in the next focus jump Change the constants related to the focus jump, such as the application start condition of the deceleration pulse or the end condition of the acceleration pulse and the deceleration pulse. When the speed of the objective lens at the end of the deceleration pulse becomes zero, the laser focus is In order to reach the first layer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a focus actuator for moving a laser focus between adjacent recording layers in a layer direction in order to read data of a plurality of layers from one side. On the other hand, in the focus jump control method in which the acceleration pulse and then the deceleration pulse are added, the level of the focus error signal is stored at the end of the deceleration pulse, and the constant relating to the focus jump in the next focus jump is changed according to the value, and the jump is performed. This is a focus jump control method characterized by performing an operation.At the end of the deceleration pulse, the target jumps to the target recording layer and adjusts so that the speed becomes zero. Even if the optimal jump pulse condition is deviated due to the distortion of the S-shaped waveform due to the interference of It can be shifted to the optimum timing by monitoring the level of the focus error signal immediately after pulse.

According to a second aspect of the present invention, when a laser focus is moved between adjacent recording layers in a layer direction in order to read data of a plurality of layers from one side, an acceleration pulse is applied to a focus actuator. Next, in the focus jump control method of adding the deceleration pulse, the level of the focus error signal is stored at the end of the deceleration pulse, and the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump is corrected based on the value. This is a focus jump control method characterized in that it is used for the next focus jump, and a brake pulse is issued even if noise or disturbance generated at an intermediate point of an S-shaped waveform caused by interference between respective layers of a multilayer disc is large. Keep your timing in time so you won't be affected Further, even if the interlayer distance fluctuates and deviates from the optimal timing for issuing a brake pulse, the timing for issuing a deceleration pulse can be corrected so that an optimal jump can be made while repeating the jump operation. .

The invention according to claim 3 of the present invention is characterized in that the wait time T from the end of the acceleration pulse to the start of the deceleration pulse is T
w has different values for the case of a focus jump from the recording layer A to the adjacent recording layer B and the case of the focus jump from the recording layer B to the recording layer A, and is characterized by being separately corrected. 3. The focus jump control method according to claim 2, wherein an optimal deceleration pulse timing can be separately learned when a focus jump is performed from the L0 layer to the L1 layer and when a focus jump is performed from the L1 layer to the L0 layer. Therefore, even when the FE signal is offset due to variations in pickup characteristics or circuit offset, no special measures for improving the characteristics are required, and the gain during servo pull-in and the maximum generated acceleration of the actuator are limited. Therefore, a stable focus jump operation can be ensured.

According to a fourth aspect of the present invention, a wait time T from the end of the acceleration pulse to the start of the deceleration pulse is obtained.
4. The wireless communication system according to claim 2, wherein w has a different value for each zone divided into an arbitrary number in the radial direction of the disk, and uses Tw by switching and changing Tw for each zone where focus jump is performed. It is a focus jump control method described, and for each zone arbitrarily divided in the radial direction of the disk, it is possible to learn the optimal timing of the deceleration pulse at the time of the focus jump, so that the local interlayer distance variation of the disk, Substrate thickness fluctuation and reflectivity fluctuation occur,
Even if the waveform shape of the FE signal changes depending on the position of the pickup, a stable focus jump operation can be secured.

According to a fifth aspect of the present invention, in the focus jump operation, depending on whether the focus jump is successful or unsuccessful, the wait from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump is determined. 5. The focus jump control method according to claim 2, wherein the correction value of the time Tw has a difference, and the correction value in the case of failure is made larger than the correction value in the case of success. When the jump operation fails, the Tw value to be corrected at a time is increased compared to when the jump operation is successful. Therefore, even when the disc is reproduced when the shape of the S-shaped waveform is large and deviates from the standard value. Focus jumps can be made quickly and stably, and the correction value when successful can be set to a small value. It is possible to suppress the transition to unstable state.

According to a sixth aspect of the present invention, there is provided a rotation driving means for rotating an optical disk on which information is recorded on a plurality of layers, and a light beam from a light source is focused to focus on a recording layer of the disk. An objective lens to be connected, a focus actuator for displacing the objective lens in a disk focus direction in accordance with a command, an optical pickup including a light source, an objective lens, a focus actuator, and a detection unit for receiving reflected light from the disk; Optical pickup moving means for moving the pickup in the radial direction of the disk, focus error signal generating means for generating a focus error signal from a read signal, and focus control means for performing a focus position control based on the focus error signal and outputting a drive instruction signal And a drive instruction signal from the focus control means A focus driving means for supplying a current to the focus actuator, a focus jump control means for outputting an acceleration pulse and a deceleration pulse to the focus driving means for moving the focus of the beam from the recording layer A to the adjacent recording layer B; The focus jump control means stores the level of the focus error signal at the end of the deceleration pulse, and corrects the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump based on the value. An optical disc device characterized by being used for the next focus jump, and the timing of issuing a brake pulse is controlled by time even if noise or disturbance generated at an intermediate point of an S-shaped waveform caused by interference between respective layers of a multilayer disc is large. Unaffected to manage with Further, even if the interlayer distance fluctuates and deviates from the optimal timing for issuing a brake pulse, the timing for issuing a deceleration pulse can be corrected so that an optimal jump can be made while repeating the jump operation. .

According to a seventh aspect of the present invention, a wait time T from the end of the acceleration pulse to the start of the deceleration pulse is obtained.
w has different values for the case of a focus jump from the recording layer A to the adjacent recording layer B and the case of the focus jump from the recording layer B to the recording layer A, and is characterized by being separately corrected. 7. The optical disc device according to claim 6, wherein an optimal deceleration pulse timing can be separately learned in a case where the focus jumps from the L0 layer to the L1 layer and in a case where the focus jumps from the L1 layer to the L0 layer. Even when the FE signal is offset due to variations in pickup characteristics or circuit offset, no special measures are required to improve the characteristics, and there is no restriction on the gain at the time of servo pull-in or the maximum acceleration generated by the actuator. Thus, a stable focus jump operation can be secured.

The invention according to claim 8 of the present invention is characterized in that the wait time T from the end of the acceleration pulse to the start of the deceleration pulse is T
8. A system according to claim 6, wherein w has a different value for each zone divided into an arbitrary number in the radial direction of the disk, and uses Tw by switching and changing Tw for each zone where focus jump is performed. An optical disk device according to claim 1,
Since the optimal timing of the deceleration pulse at the time of a focus jump can be learned for each zone arbitrarily divided in the radial direction of the disc, local variations in interlayer distance, variations in substrate thickness, and variations in reflectivity can be learned. As a result, even if the waveform shape of the FE signal changes depending on the position of the pickup, a stable focus jump operation can be secured.

According to a ninth aspect of the present invention, in the focus jump operation, when the focus jump is successful or unsuccessful, the wait from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump is determined. 9. The optical disc device according to claim 6, wherein a correction value for the time Tw is made different, and a correction value for a failure is made larger than a correction value for a success. If the operation fails, the Tw is corrected at once compared to the case where the jump operation is successful.
Since the value of is increased, even when the disc is reproduced with the shape of the S-shaped waveform greatly deviating from the standard value, the focus jump can be performed quickly and stably, and the correction value upon success can be set to a small value. It is possible to suppress a transition to an unstable state when a mistake is made in one learning.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows a configuration of an optical disk apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes an optical disk having two recording layers, an A layer and a B layer,
Is a rotation driving means for rotating the optical disk 1, 3 is an objective lens for converging a light beam from a light source to focus on a recording layer of the disk, and 4 is a focus for displacing the objective lens 3 in a disk focus direction according to a command. An actuator 5 includes a light source, an objective lens 3, a focus actuator 4, and an optical pickup including a detection unit that receives reflected light from the disk 1. 12 denotes an optical pickup moving unit that moves the optical pickup 5 in a radial direction of the disk 1. 6 is a focus error signal generating means for generating a focus error signal from the read signal, 7 is a focus control means for performing a focus position control based on the focus error signal and outputting a drive instruction signal, and 8 is a drive instruction signal from the focus control means 7 To supply current to the focus actuator 4 The focus driving means 9 is a focus jump control means for outputting an acceleration pulse and a deceleration pulse to the focus driving means 8 in order to move the focal point of the beam from the recording layer A to the adjacent recording layer B. , A servo controller including the focus jump control means 9.

Next, the operation of the present embodiment will be described. The optical disk 1 is mounted on the rotation driving means 2 and rotates at a predetermined rotation speed. The data on the optical disc 1 is obtained by collecting laser light output from a laser diode (not shown) mounted on the optical pickup 5 onto a data surface of the optical disc 1 via an optical element (not shown) and an objective lens 3. Be lighted. The optical pickup 5 can be moved in the radial direction of the optical disc 1 by the optical pickup moving means 12. The laser reflected light from the optical disk 1 is focused on a photodetector (not shown) on the optical pickup 5 with information on the unevenness of the data surface. The light collected by the photodetector is converted into an electric signal, and a focus error signal (FE signal), which is an error signal for controlling the focus direction, is generated in the FE signal generation unit 6. The FE signal is input to the servo controller 11, and at the time of data reproduction, the focus control unit 7
Control is performed so that the FE signal becomes “0”, and the output is converted into a thrust in the focus direction of the objective lens by the focus driving means 8 and the focus actuator 4 to form a feedback control system, thereby forming the objective lens. 3 is performed. Further, when the focus is moved to another recording layer, the servo controller 11 switches the focus jump control means 9 provided therein to the focus control means 7 with the switch 10 to cause the focus jump to the target recording layer. The focus jump control means 9 controls the R which is secured in the learning table 13 in the servo controller.
Learning of the wait time Tw is performed using AM.

FIGS. 2 and 3 show a focus jump operation in the present embodiment, FIG. 2 shows a process at the time of a focus jump, and FIG. 3 shows signals during the focus jump operation. The processing at the time of the focus jump will be described using these. First, the focus servo is turned off at the point L0 where the servo is currently applied.
Then, a predetermined acceleration pulse (V1) is applied to the focus actuator 4 (S2). The acceleration pulse is FE
The signal is output until the signal exceeds the comparison level LVL2, and then turned off. The acceleration pulse application time (T1) during this period is measured by a timer and stored (S4 to S4).
7). After the acceleration pulse is output, mask weight 1
During the period, LVL2 is not detected to prevent erroneous detection due to noise.

After the acceleration pulse is stopped and a time Tw has elapsed, a deceleration pulse is applied to the focus actuator (S8). The pulse at this time is the acceleration pulse (V1) 2
The application time is set to T1 / 2. The relationship between the acceleration pulse and the deceleration pulse may be set as long as the relationship of pulse height × time is equal between acceleration and deceleration. After applying the deceleration pulse and after a certain time (mask weight 2),
The level of the FE signal is monitored, and it is determined whether the FE has exceeded the destination during the pulse (S9 to S12). If the deceleration pulse time exceeds T1 / 2 (S1
4) If the destination point is exceeded, the flag FEOVER
Is set to 1 (S13). The mask weight 2 is provided to prevent erroneous detection of the FEOVER flag check due to FE noise.

At the end of the deceleration pulse, the value (FEb) of the FE signal at that time is stored (S15), and the focus servo is turned on (S16). The jump operation is completed above, but after that, use it for the next focus jump,
The wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse is corrected (S17 to S21). The correction method is as follows: (1) When FEOVER = 1 (S19) Tw (Next) = Tw (Current) −dW (2) When FEOVER = 0 and FEb> LVL3 (S21) Tw (Next) = Tw (Current) + DW (3) Other (S20) Tw (Next) = Tw (Current) dW is the amount of time to be corrected in one jump, and sets a value suitable for the system. In (1), it is determined that the deceleration pulse is emitted late, in (2), it is determined that the deceleration pulse is early, and in (3), it is determined that the deceleration pulse is emitted at an appropriate timing. Tw in the direction to correct it
To change. At the time of the next jump, jump is performed using the corrected Tw.

As described above, according to the first embodiment, the timing at which the brake pulse is issued is managed in terms of time even if the noise or disturbance generated at the midpoint of the S-shaped waveform caused by the interference between the respective layers of the multilayer disc is large. To be able to perform the optimal jump while repeating the jump operation, even if it is not affected by the The timing of issuing a pulse can be modified.

(Embodiment 2) FIG. 4 shows Embodiment 2 of the present invention. The table of Tw managed in the servo controller 11 jumps from the L0 layer to the L1 layer, Indicates that the data is separately stored when jumping to the L0 layer. Other configurations are the same as those of the first embodiment shown in FIG.

As described above, according to the second embodiment, L
Focus jump from layer 0 to layer L1 and L1
Since the optimum deceleration pulse timing can be separately learned when a focus jump is performed from the layer to the L0 layer, measures are taken to improve the characteristics even when the FE signal is offset due to pickup characteristics variation or circuit offset. Is not particularly required, and a stable focus jump operation can be ensured without being limited by the gain at the time of servo pull-in or the maximum generated acceleration of the actuator.

(Embodiment 3) FIG. 5 shows Embodiment 3 of the present invention, in which a Tw table managed in the servo controller 11 is divided into zones arbitrarily divided in the disk radial direction. It is stored separately for each case and when jumping from the L0 layer to the L1 layer and when jumping from the L1 to the L0 layer. Other configurations are the same as those of the first embodiment shown in FIG.

As described above, according to the third embodiment, the optimum timing of the deceleration pulse at the time of the focus jump can be learned for each zone arbitrarily divided in the radial direction of the disk. A stable focus jump operation can be ensured even if local interlayer distance variation, substrate thickness variation, and reflectance variation occur, and the FE signal waveform shape changes depending on the position of the pickup.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention, in which processing (S22, S23) is added to the flowchart shown in FIG. In the present embodiment, the correction value dW managed in the servo controller 11 differs depending on the result of success / failure of the focus jump, and the correction value dW_NG when the focus jump fails is determined when the focus jump succeeds. Is larger than the correction value dW_OK. In this example, dW_NG = dW_OK * 3.

As described above, according to the fourth embodiment, when the jump operation has failed, the Tw value to be corrected at one time is larger than when the jump operation has succeeded. Even when playing a disc with a large deviation from the standard value, the focus jump can be performed quickly and stably, and the correction value when succeeded can be set to a small value. It is possible to suppress the transition to a proper state.

In each of the above embodiments, the method of correcting the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse at the time of the focus jump has been described. Conditions to make the pulse height of the pulse variable, to make the application time of the acceleration pulse and the deceleration pulse variable, to make the application time ratio of the acceleration pulse and the deceleration pulse variable, or to start the application of the acceleration pulse and the deceleration pulse Is variable, or the conditions for terminating the application of the acceleration pulse and the deceleration pulse are variable, whereby the same control can be performed.

[0030]

As apparent from the above embodiment, the present invention measures the level of the focus error signal at the end of the deceleration pulse, and determines whether the jump timing is optimal based on the measured value. According to the result, in the next focus jump, the time from the acceleration pulse to the deceleration pulse, or the pulse height of the acceleration pulse and the deceleration pulse, or the application time of the acceleration pulse and the deceleration pulse,
Alternatively, change the constants related to focus jump, such as the application start condition of acceleration pulse and deceleration pulse, or the end condition of acceleration pulse and deceleration pulse, and focus the laser when the speed of the objective lens at the end of deceleration pulse becomes zero. Is moved gradually so that it just reaches the target layer. In the case where the balance or waveform shape of the FE signal is distorted due to local characteristic change of the disk or characteristic variation of the pickup, and Even when the maximum acceleration generated by the actuator is small, the focus jump can be stably performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of a focus jump process according to the first embodiment of the present invention;

FIG. 3 is a waveform diagram of a focus jump operation according to the first embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of an optical disk device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an optical disk device according to a third embodiment of the present invention.

FIG. 6 is a flowchart of focus jump processing according to Embodiment 4 of the present invention.

FIG. 7 is a focus error signal waveform diagram of a two-layer disc.

FIG. 8 is a waveform diagram of a focus jump operation in a conventional optical disc device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Rotation drive means 3 Objective lens 4 Focus actuator 5 Optical pickup 6 FE signal generation means 7 Focus control means 8 Focus drive means 9 Focus jump means 10 Switch 11 Servo controller 12 Optical pickup moving means 13 Learning table

Claims (9)

[Claims] 1. A focus jump control method for applying an acceleration pulse and then a deceleration pulse to a focus actuator when a laser focus is moved between adjacent recording layers in a layer direction in order to read data of a plurality of layers from one surface. A focus error signal level is stored at the end of the deceleration pulse, a constant relating to the focus jump in the next focus jump is changed according to the value, and a jump operation is performed. 2. A focus jump control method for applying an acceleration pulse and then a deceleration pulse to a focus actuator when a laser focus is moved between adjacent recording layers in a layer direction in order to read data of a plurality of layers from one side. The level of the focus error signal is stored at the end of the deceleration pulse, and the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse at the time of the next focus jump is corrected based on the value and used for the next focus jump. And a focus jump control method. 3. The wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse depends on whether a focus jump from the recording layer A to the adjacent recording layer B or a focus jump from the recording layer B to the recording layer A. 3. The method according to claim 2, wherein the values have different values and are modified separately.
The described focus jump control method. 4. The wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse has a different value for each zone divided into an arbitrary number in the radial direction of the disk, and is a zone where a correction is performed and a focus jump is performed. 4. The focus jump control method according to claim 2, wherein Tw is switched for each use. 5. In the focus jump operation,
A difference is made between the correction value of the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump between the case where the focus jump is successful and the case where the focus jump is unsuccessful. 5. The focus jump control method according to claim 2, wherein the correction value in the case is made larger. 6. A rotation driving means for rotating an optical disc having information recorded on a plurality of layers, an objective lens for converging a light beam from a light source to focus on a recording layer of the disc, and a command for the objective lens. A focus actuator for displacing the optical pickup in the disk focus direction, an optical pickup including the light source, the objective lens, the focus actuator and detection means for receiving reflected light from the disk, and light for moving the optical pickup in a radial direction of the disk. Pickup moving means, a focus error signal generating means for generating a focus error signal from the read signal, a focus control means for performing a focus position control based on the focus error signal and outputting a drive instruction signal,
A focus driving means for supplying a current to the focus actuator according to a driving instruction signal from the focus control means, and an acceleration pulse and a deceleration for the focus driving means for moving the focus of the beam from the recording layer A to the adjacent recording layer B. Focus jump control means for outputting a pulse, wherein the focus jump control means stores the level of the focus error signal at the end of the deceleration pulse, and stores the level of the focus error signal from the end of the acceleration pulse in the next focus jump to the deceleration pulse. An optical disc device wherein a wait time Tw until start is corrected and used for the next focus jump. 7. The wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse varies depending on whether a focus jump from the recording layer A to the adjacent recording layer B or a focus jump from the recording layer B to the recording layer A. 7. A method according to claim 6, wherein the values have different values and are modified separately.
An optical disk device as described in the above. 8. The wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse has a different value for each zone divided into an arbitrary number in the radial direction of the disk, and is a zone in which correction is performed and focus jump is performed. 8. The optical disk device according to claim 6, wherein Tw is switched for each use. 9. In the focus jump operation,
A difference is made between the correction value of the wait time Tw from the end of the acceleration pulse to the start of the deceleration pulse in the next focus jump between the case where the focus jump is successful and the case where the focus jump is unsuccessful. 9. The optical disk device according to claim 6, wherein the correction value in the case is made larger.