JP2008262657A - Device and method for recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure recording stability, for example, during recording by an optical disk camcorder. <P>SOLUTION: The device (1) for recording includes focus error signal generation means (50, 54 and so forth) for generating focus error signals corresponding to the focus state of an optical beam on an optical disk, and spindle drive signal generation means (40, 41 and so forth) for generating spindle drive signals corresponding to a rotational speed of the optical disk. This device 1 further includes a control means (30) for controlling a recording operation of the device to deal with gyro effects generated during recording based on a spindle drive signal generated in addition to or in place of the focus error signal thus generated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a recording apparatus and a recording method such as an optical disc camcorder and an optical disc drive that use an optical disc such as a DVD-R (Digital Versatile Disk-Recordable) as a recording medium.

  In this type of recording apparatus, data received via the host interface is converted into a signal for recording on an optical disk inside the drive, and recorded as a digital signal on a disk track by an optical pickup. Here, it is known that when the optical disk is distorted due to the gyro effect during recording, the positional relationship between the pickup and the disk changes, resulting in recording quality (see FIG. 3).

  Among such positional changes, a technique has been proposed in which a rotation mechanism is provided between the camcorder housing and the optical disk including the spindle in order to reduce the change in the angle between the disk and the pickup called skew and realize stable recording. Yes. For example, according to Patent Document 1, the drive chassis is rotatably supported around at least one predetermined rotation axis. According to Patent Document 2, a base plate assembly on which an optical disk is mounted is supported so as to be swingable with respect to a camcorder body via a horizontal rotation support shaft. According to Patent Document 3, the optical pickup is provided vertically below the rotation axis of the optical disc in the actual use state. According to these technologies, it is possible to suppress the occurrence of the gyro effect by making it difficult for the posture change of the housing to be transmitted to the optical disc, or to reduce the distortion of the optical disc in the direction that is predicted to occur most frequently. Is possible.

  However, layout restrictions such as the need for a space for tilting the disk in the housing impede downsizing. Moreover, in patent document 1, when the frequency of the attitude | position change added to a housing | casing is outside the corresponding frequency of a rotation mechanism, there is no effect. In addition, in both Patent Documents 1 and 2, since the gyro effect suddenly appears at the moment when the posture change is outside the swingable range, the distortion change of the optical disc at that time may be further increased. On the other hand, in Patent Document 3, the skew in the radial direction of the optical disc can be reduced with respect to the posture change in the direction in which the occurrence frequency is highest, but the skew in the tangential direction remains.

  In practice, the moment applied to the optical disk by the gyro effect distorts the entire disk in a complicated manner due to the elasticity of the optical disk and the center of the optical disk being fixed to the spindle. As a result, not only the occurrence of skew, but also the positional relationship between the pickup and the optical disc in the focus direction changes, and the normal focus servo cannot fully compress the residual error of the focus position. Such a change in residual error changes the condition of the optical pulse required for recording, and an optical disc recorded under normal conditions under this circumstance cannot avoid the deterioration of the recorded signal quality. The same phenomenon occurs when a notebook personal computer with a built-in optical drive is lifted and moved, or the attitude of a portable type optical drive is changed. In these devices, it is more difficult than a camcorder to secure a space for the drive to move its posture.

  Therefore, it is conceivable to set the servo gain high so that the control position is not affected even if the optical disc is distorted. However, when the servo gain is constantly set high, various kinds of crosstalk leaking into the focus signal causes an increase in trace sound and an unnecessary increase in actuator drive current. Especially in applications such as camcorders, unnecessary sound may be recorded due to an increase in trace sound, and an increase in actuator current may cause damage to the pickup due to heat generated in the coil, leading to a decrease in battery operating time. There is sex.

  Therefore, the period during which the servo gain is set high should be limited to only the period during which the recording quality is likely to deteriorate due to the gyro effect. For example, according to Patent Document 4, the servo gain characteristic of the driving means for rotationally driving the optical disc is set higher when used in the dynamic state than when used in the static state. According to Patent Document 5, when the phase of the spindle motor is controlled by a phase servo corresponding to the phase difference between the waveform of the frequency corresponding to the rotation speed of the spindle motor and a preset reference waveform, there is a disturbance. The phase servo gain is set high so that the rotation fluctuation of the spindle servo is suppressed. However, what is to be solved in these documents is that the rotational speed of the spindle changes due to the gyro effect, and as a result, the timing at which the pickup section traces a specific position on the disk shifts. This is a servo that changes the servo characteristics of the spindle itself depending on the error signal status in a closed servo system called a servo, and is not related to other servo systems such as focus servo. It cannot prevent the deterioration of quality.

Japanese Unexamined Patent Publication No. 2000-21146 JP 2001-101675 A JP 2001-101855 A JP 2001-118320 A Japanese Patent Laid-Open No. 10-172231

  The present invention has been made in view of, for example, the above-described problems, and it is assumed that the focus positional relationship between the optical disk and the pickup has changed due to the gyro effect without a layout limitation and a steady increase in power consumption. Another object of the present invention is to provide a recording apparatus and a recording method capable of continuing recording while maintaining sufficient recording quality.

In order to solve the above problems, a recording apparatus according to claim 1 of the present invention
A recording apparatus comprising: a focus actuator driving unit that focuses a light beam at a predetermined position of an optical disc; and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc,
A focus error signal generating means for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
Spindle drive signal generating means for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
In addition to or instead of the generated focus error signal, control means for controlling a recording operation in the recording apparatus based on the generated spindle drive signal to cope with a gyro effect generated during recording is further provided. .

In order to solve the above problem, a recording method according to claim 6 of the present invention
A recording method using a recording apparatus that includes a focus actuator driving unit that focuses a light beam at a predetermined position of an optical disc and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc. And
A focus error signal generating step for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
A spindle drive signal generating step for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
A control step of controlling a recording operation in the recording apparatus in response to a gyro effect generated during recording based on the generated spindle drive signal in addition to or instead of the generated focus error signal.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, a recording apparatus and a recording method according to an embodiment of the present invention as the best mode for carrying out the invention will be described in order.

(Embodiment of recording apparatus)
(1)
In order to solve the above-described problem, the recording apparatus according to this embodiment
A recording apparatus comprising: a focus actuator driving unit that focuses a light beam at a predetermined position of an optical disc; and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc,
A focus error signal generating means for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
Spindle drive signal generating means for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
In addition to or instead of the generated focus error signal, control means for controlling a recording operation in the recording apparatus based on the generated spindle drive signal to cope with a gyro effect generated during recording is further provided. .

  According to the present embodiment, when optically recording desired data on an optical disc, even when a gyro effect occurs, recording can be continued without causing deterioration in recording quality.

  First, at the time of recording, a light beam is focused on a predetermined position of the optical disk, for example, a recording layer, by a focus actuator driving means having an objective lens on an optical pickup, for example. Further, the optical disk is driven to rotate by a spindle driving means having a spindle motor, for example.

  Meanwhile, a focus error signal corresponding to the focus state of the light beam on the optical disc is generated regularly or irregularly by a focus error signal generating means including an optical detector, an amplifier, and the like. On the other hand, a spindle drive signal corresponding to the rotational speed of the optical disk is generated by a spindle drive signal generating means including an optical detector, an amplifier, and the like.

  Here, as described above, for example, when the recording apparatus changes its posture in the pan direction or the roll direction while the optical disk is rotated at a high speed, a gyro effect may occur, and the recording quality may be deteriorated due to the gyro effect.

  Therefore, the occurrence of the gyro effect is detected based on the spindle drive signal generated as described above in addition to or instead of the focus error signal generated as described above. In order to cope with the generated gyro effect, the recording operation in the recording apparatus is controlled by control means such as a controller. For example, the gain of various servos including the focus servo is increased or decreased, or the recording operation is interrupted. Thus, “controlling the recording operation” is a broad concept including not only changing various parameters defining the recording operation by the recording apparatus but also controlling various operations constituting the recording operation. is there.

  As a result, even if the focus position relationship between the optical disk and the pickup changes due to the gyro effect, the recording is continued with sufficient recording quality without any restrictions on the layout or constant increase in power consumption. It becomes possible.

In particular, according to the research of the present inventor, when the gyro effect occurs, the spindle drive signal is different from the focus error signal, and the level is increased regardless of the direction of the gyro moment. That is, as long as the gyro effect occurs, the spindle drive signal changes to the same polarity, so that the threshold value determination becomes relatively easy. Furthermore, if the threshold value is determined for the focus error signal, the determination accuracy can be improved.
(2)
In one aspect of the recording apparatus according to the present embodiment,
The control means changes a focus servo characteristic in the focus actuator driving means depending on whether or not the level of the generated spindle drive signal exceeds a predetermined first threshold value.

According to this aspect, when the level of the generated spindle drive signal exceeds the predetermined first threshold value, for example, the focus gain in the focus actuator driving unit is increased by a predetermined amount. On the other hand, when the first threshold value is not exceeded, the normal gain may be restored. Alternatively, the target value of the focus servo may be changed. Here, the “first threshold value” indicates that the gyro effect is exerted on the optical disc so that a decrease in recording quality cannot be ignored in practical use with respect to a spindle drive signal level in a steady state where there is no gyro effect at a predetermined rotational speed. As a lower limit value of the level of the spindle drive signal estimated to be present, this is a value offset by a value determined in advance by experiment or simulation. This threshold value may be changed as appropriate according to the recording state of the recording apparatus. Note that the description of “changing the focus servo characteristics” is not intended to prevent changing other servo characteristics such as the spindle servo characteristics. Further, this aspect is effective not only in the recording apparatus but also in the reproducing apparatus.
(3)
Thus, in the aspect of determining the threshold value of the spindle drive signal,
The control means includes
The level of the generated spindle drive signal exceeds a predetermined first threshold, and
When the level of the generated focus error signal exceeds a predetermined second threshold,
You may make it perform the interruption process which interrupts the recording by the said recording device.

According to this aspect, the occurrence of the gyro effect is more accurately estimated based on the focus error signal as well as the spindle drive signal. When the focus servo characteristic is changed and the influence of the gyro effect cannot be endured, the recording by the recording apparatus is interrupted. Thereby, it is possible to avoid a decrease in recording quality. The “second threshold value” is a lower limit value of the focus error signal level at which it is estimated that the gyro effect is exerted on the optical disc so that the deterioration in recording quality cannot be ignored in practice. It is a predetermined value. In the focus error signal, the effect of the gyro effect does not necessarily appear as an increase in level, so in addition to or instead of threshold determination, the threshold code, the frequency of the signal, and other signal fluctuation modes are also considered. Thus, the occurrence of the gyro effect may be estimated.
(4)
In the aspect of performing the interruption process in this way,
The control means may perform the interruption process after recording the desired data to be recorded up to the recording unit boundary of the optical disc.

According to this aspect, even if the occurrence of the gyro effect is estimated, the focus servo is not lost, so the recording is not interrupted halfway and the recording is performed up to the boundary of the recording unit such as the error correction block of the optical disc. Let it continue. This avoids unnecessary error correction at the recording interruption portion. If there is no room in the data buffer, recording may be resumed.
(5)
In the aspect in which the threshold determination of the spindle drive signal is performed as described above,
In detecting the level of the generated spindle drive signal,
Band limiting means for performing band limitation on the generated spindle drive signal;
It is preferable to further include an upper end holding unit that extracts an upper end envelope of the signal level subjected to the band limitation for each rotation period of the optical disc.

According to this aspect, the band in which the spindle drive signal is not related to the influence of the gyro effect is limited by the band limiting unit such as the low pass filter, and then the upper end envelope is extracted by the upper end holding unit such as the peak hold circuit. As a result, the fluctuation component synchronized with the rotation period of the disk can be eliminated, so that the accuracy of the threshold determination is improved. In addition, compared with the case where the component synchronized with the rotation period of the disk is restricted only by the band limiting means, the detection delay of the signal change is reduced, which is preferable in practice.
(6)
In the aspect of performing the threshold determination as described above,
Measuring means for measuring the level of the focus error signal and the spindle drive signal in a steady state (in other words, not affected by the gyro effect) over a period of one rotation period or more of the optical disc;
You may further provide the setting means which sets at least one among the said 1st threshold value and the said 2nd threshold value based on the level of the said steady state measured.

According to this aspect, considering that both the focus error signal and the spindle drive signal have a component synchronized with the rotation of the optical disc (hereinafter also referred to as “rotation synchronization component”), the first threshold value and the second threshold value At least one of them can be suitably set.
(7)
In an aspect further comprising this measuring means and setting means,
The measuring unit may measure the level of the focus error signal in the steady state in a state where the focus servo characteristic in the focus actuator driving unit is changed.

According to this aspect, the comparison between the level of the focus error signal and the second threshold as described above is performed in a state where the focus servo characteristic is changed by the control means, for example, in a state where the focus servo gain is increased. However, the second threshold value corresponding to this state can be set in advance. Conversely, when measuring the level of the focus error signal in the steady state, it is of course possible to set the threshold value in consideration of the gain increase without increasing the servo gain.
(8)
In an aspect further comprising this measuring means and setting means,
The setting means may set at least one of the first threshold value and the second threshold value so as to be larger than a component synchronized with the rotation of the optical disc included in the focus error signal and the spindle drive signal. .

According to this aspect, the threshold value can be set to a level that does not erroneously detect the rotation synchronization component of the optical disc. Incidentally, the rotation synchronization component appearing in the focus error signal is mainly due to the disk shake component. The rotation synchronization component appearing in the spindle drive signal is mainly an imbalance component of the disk.
(9)
In an aspect further comprising this measuring means and setting means,
Specifying means for specifying a correspondence relationship between a periodic increase / decrease of the focus error signal and the spindle drive signal measured in the steady state and a rotation angle of the optical disc;
Threshold adjustment means for increasing or decreasing the set first or second threshold value in synchronization with the rotation of the optical disc based on the specified correspondence relationship may be further provided.

  According to this aspect, since the correspondence between the periodic increase / decrease of each signal in the steady state and the rotation angle of the optical disc is kept substantially constant, by increasing / decreasing each threshold value in synchronization with the rotation, it becomes much smaller. The change can be detected, thereby improving the accuracy of detecting the gyro effect.

(Embodiment of recording method)
(10)
In order to solve the above problems, the recording method of the present embodiment
A recording method in a recording apparatus that includes a focus actuator driving unit that focuses a light beam on a predetermined position of an optical disc and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc. And
A focus error signal generating step for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
A spindle drive signal generating step for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
A control step of controlling a recording operation in the recording apparatus in response to a gyro effect generated during recording based on the generated spindle drive signal in addition to or instead of the generated focus error signal.

  According to the recording method of the present embodiment, as in the case of the recording apparatus of the present embodiment described above, the focus of the optical disc and the pickup can be achieved by the gyro effect without a layout limitation and a steady increase in power consumption. Even if the positional relationship changes, it is possible to continue recording while maintaining sufficient recording quality.

  Note that the recording method of the present embodiment can also adopt various aspects similar to the various aspects of the recording apparatus of the present embodiment described above.

  The operation and other advantages of the present embodiment will be clarified from the examples described below.

  Embodiments of the present invention will be described below with reference to the drawings.

(1-1) Configuration First, the configuration of the recording apparatus 1 according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a block diagram conceptually showing the basic structure of a recording apparatus 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the recording apparatus 1 is, for example, an optical disk drive built in a portable type or an optical disk camcorder. The recording apparatus 1 has a host interface 31 that exchanges data and commands with the outside. Data to be recorded sent from a host (not shown) is once stored in the data buffer 32. During recording, the encoder 33 sequentially takes in the data stored in the data buffer 32 and encodes it in a predetermined format according to the optical disk 100 to be recorded. The encoded data is sent to an LDD (laser diode driver) 11 on the pickup 10, and the LDD 11 drives the LD (laser diode) 12 with a pulse width and power suitable for recording, so that a light beam is emitted. The emitted light beam is guided to the objective lens 15 through the optical system 13 such as a polarizing plate and a half mirror, and is focused on a recording layer (not shown) on the optical disc 100 by the objective lens 15, so Data recording is performed by thermal or optical modification.

  The pickup 10 further includes an actuator 16 that drives the objective lens 15 in a predetermined direction in order to focus the light from the LD 12 onto the recording layer of the optical disc 100 and an optical detector 17 that detects the light reflected by the optical disc 100.

  The optical disc 100 is fixed to the spindle shaft 72 by a clamper 712 and a turntable 711 and is rotated at a predetermined number of rotations by a spindle motor 70. The spindle motor 70 is controlled so that rough rotation speed information is obtained by its own FG (Frequency Generator) at the initial stage of rotation control, and this rotation speed becomes constant.

  The reproduction signal corresponding to the reflected light from the optical disc 100 detected by the optical detector 17 includes a rotation synchronization signal at the time of recording and reproduction. The amplification circuit 40 amplifies the signal, and the rotation synchronization signal detection / rotation control circuit 41 which is a specific example of the “spindle drive signal generation means” of the present invention detects the rotation synchronization signal from the amplified signal, A spindle error signal is generated so that the frequency and phase of the rotation synchronization signal become a predetermined frequency and a predetermined phase. The spindle driver 42 which is a specific example of the “spindle driving means” of the present invention generates a spindle drive signal SPD corresponding to the spindle driver 42, thereby controlling the rotational speed of the spindle motor 70.

  On the other hand, the reflected light from the optical disc 100 detected by the optical detector 17 also includes information on the focus state of the light beam on the optical disc 100, which is a specific example of the “focus error signal generating means” of the present invention. A focus error signal FE is generated by calculation in an amplifier circuit 50. The gain switching circuit 51 switches the servo gain according to the type of the optical disc 100, the current double speed, and the like. The focus error signal FE is amplified according to the servo gain, and after the frequency characteristics are optimized by the focus servo filter 52, the focus error signal FE is sent to the actuator driver 53. Based on this signal, the actuator driver 53 which is a specific example of the “focus actuator driving means” of the present invention drives the actuator 16 on the pickup 10 and adjusts the distance between the objective lens 15 and the optical disc 100 to perform focusing. Maintain state.

  The shock sensor 60 is provided in the recording apparatus 1, detects a short-time impact applied to the recording apparatus 1, generates a shock detection signal, and sends it to the controller 30. Such a sensor normally detects an impulse impact and tries to protect the operation at the time of a collision, and is a type that cannot detect a posture change with a relatively long change time such as chasing a subject. Therefore, the presence or absence of the shock sensor 60 does not affect the present invention, and it can be said that the present invention is effective for a device in which the shock sensor 60 is mounted. Of course, instead of monitoring the spindle drive signal SPD using a sensor that can detect a change in posture with a long change time, it is possible to determine the gyro effect based on its output and apply the recording interruption sequence described below. However, such a sensor is usually more expensive than the present embodiment.

  The controller 30 is a specific example of the “control means” of the present invention, and controls the entire operation of the recording apparatus 1. The controller 30 stops and sets the rotation speed of the spindle motor 70, manages the state of the spindle motor 70, and operates the encoder 33. Start / end and selection of encoding method, characteristic setting of actuator 16 focus servo, tracking servo, traverse servo, etc., detection of servo deviation, command exchange with host via host interface 31, and operation status of recording apparatus 1 as a result Set up, etc.

  Particularly in the configuration of the present embodiment, in addition to the components of the recording apparatus 1, a filter 54 that performs band limitation on the focus error signal FE, and a second threshold value that is output from the filter 54 to the controller 30 is set. And a comparator 56 for determining whether or not it exceeds. Thereby, it is possible to determine whether or not the band-limited focus error signal FE is within the second threshold.

  In addition, the band is limited to the spindle drive signal SPD, and the low-pass filter 43, which is a specific example of the “band-limiting unit” of the present invention, The envelope is extracted and a peak hold circuit 44, which is a specific example of the “upper end holding means” of the present invention, and whether or not the output from the peak hold circuit 44 exceeds a first threshold value instructed to the controller 30 is determined. And a comparator 46. As a result, it is possible to determine whether or not the band-limited spindle drive signal SPD is within the first threshold.

  As can be seen from the above, by detecting the convergence of the gyro effect based on these judgment results and controlling the recording operation, even if the focus position relationship between the optical disk and the pickup changes due to the gyro effect, sufficient recording quality can be obtained. It is possible to continue recording while keeping

  Next, the relationship between the moving direction of the recording apparatus 1 and the gyro effect according to the embodiment will be described with reference to FIGS. Here, FIG. 2 is a schematic diagram illustrating a relationship between the pickup of the recording apparatus 1 and the optical disc when the attitude of the recording apparatus 1 is not changed according to the embodiment (the upper diagram is a perspective view of the recording apparatus 1). (The figure below shows the side view of the recording apparatus 1 as seen from the B1 direction.) FIG. 3 is a schematic diagram illustrating a relationship between the moving direction of the recording apparatus 1 and the gyro effect when the posture is changed in the roll direction according to the embodiment (the upper figure is a perspective view of the recording apparatus 1, The lower figures show side views of the recording apparatus 1 as viewed from the B1 direction).

  2 and 3, the three axes of the A1-A2 axis, the B1-B2 axis, and the C1-C2 axis are orthogonal to each other, and the rotation axis of the optical disc 100, that is, the direction along the spindle shaft 72 is defined as the A1-A2 axis. . The rotation around the A1-A2 axis is also called the rotation in the tilt direction, the rotation around the B1-B2 axis is also called the rotation in the pan direction, and the rotation around the C1-C2 axis is also called the rotation in the roll direction. During shooting by an optical disk camcorder as an example of the recording apparatus 1, the optical disk 100 is fixed to the spindle shaft 72 by the clamper 712 and the turntable 711, and writing is performed by rotating around the A1-A2 axis.

  Here, as shown in FIG. 2, if the posture of the recording apparatus 1 is not changed in the pan direction or the roll direction, the optical disk 100 is not distorted by the gyro effect, and the frictional resistance against the rotation of the spindle motor 70 is substantially constant. .

  However, as shown in FIG. 3, when a change in posture in the pan direction or roll direction is applied to the recording apparatus 1, the optical disc 100 is distorted by the gyro effect. Specifically, with respect to the rotation in the pan direction around the B1-B2 axis, a torque T = Ia × Wa × Wb called a gyro moment force around the C1-C2 axis and the roll direction around the C1-C2 axis on the other hand For rotation, it is known that torque T = Ia × Wa × Wc is generated around the B1-B2 axis (Ia: moment of inertia around the rotation axis A1-A2, Wa: around the A1-A2 axis) Angular velocity, Wb: angular velocity around the B1-B2 axis, Wc: angular velocity around the C1-C2 axis). The spindle shaft 72 that supports the optical disc 100 changes its orientation together with the housing, whereas the optical disc 100 itself tends to tilt in the direction of another arrow AR1 due to the action of the gyro moment, so that the optical disc 100 itself is temporarily Is distorted (see FIG. 3).

  Further, when the optical disc 100 receives a gyro moment in the direction of the arrow AR1, the spindle shaft 72 receives a force for tilting in the direction of the arrow AR2. As a result, the pressing force between the spindle shaft 72 and the shaft bearing 73 in the direction of the arrow AR3 increases, so that the frictional resistance against the rotation of the spindle motor 70 also increases. Even in this state, the spindle servo for maintaining a constant rotational speed works, and the rotation synchronization signal detection / rotation control circuit 41 increases the spindle drive signal SPD. Therefore, the spindle drive signal SPD affected by the gyro effect increases regardless of the rotation direction. A signal diagram showing the focus error signal FE and the spindle drive signal SPD when the recording apparatus 1 that is actually operating according to the embodiment is moved in various directions will be described with reference to FIG.

FIG. 4 shows, from above, a focus error signal FE and a spindle drive signal SPD at the time of the following attitude change.
-When the posture changes in the pan direction, when the posture changes in the opposite pan direction,
・ When changing posture in the roll direction, when changing posture in the opposite direction of the roll,
-When the posture changes in the tilt direction, and when the posture changes in the opposite direction of the tilt.

  As can be seen from FIG. 4, the focus servo disturbance occurs due to the gyro effect during the two operations of the posture change in the pan direction and the reverse direction of the pan, and the posture change in the roll direction and the reverse direction of the roll. is there. In either case, an increase in the residual amount of the focus error signal FE due to the gyro effect and a temporary increase in the spindle drive signal SPD are observed. When the gyro effect is observed in this way, the focus servo gain may be selectively increased so that the focus servo residual error can be further compressed.

  Further, the posture change in the tilt direction and the reverse direction of the tilt does not cause a gyro effect and has almost no influence on the focus error, so there is no need to increase the focus servo gain. However, the fact that the posture change is continuing means that when the posture change ends, that is, when the posture change in the tilt direction ends, it is also predicted that an impact in the pan direction or the roll direction will occur. . Therefore, it is also effective to increase the focus servo gain from the preventive viewpoint of improving the impact resistance at the end of posture change.

  Here, the polarity of the focus error signal FE is reversed depending on the rotation direction, that is, the pan direction and the pan reverse direction even in the same pan movement. On the other hand, the spindle drive signal SPD is characterized by changing to the same polarity in both directions.

  This feature will be described with reference to FIGS. Here, FIG. 5 is a signal diagram illustrating a change state of the focus error signal FE when affected by the gyro effect according to the embodiment. FIG. 6 is a signal diagram illustrating a change in the spindle drive signal SPD when affected by the gyro effect according to the embodiment.

  As shown in FIG. 5, the focus error signal FE when affected by the gyro effect behaves in various ways, and the polarity due to the effect of the gyro effect is not uniform. Therefore, in order to detect the occurrence of the gyro effect by observing the focus error signal FE, it is necessary to set a threshold corresponding to various behaviors or to set a determination criterion different from the threshold.

On the other hand, as shown in FIG. 6, the spindle drive signal SPD when affected by the gyro effect changes to the same polarity. Therefore, in order to detect the occurrence of the gyro effect by observing the spindle drive signal SPD, there is an advantage that it is possible to set only the threshold value on the increase side of the spindle drive signal SPD.

  More specifically, the focus error signal FE is a signal representing the focus target value deviation itself, and its monitoring is effective for improving the recording quality. However, although it is possible to detect the effect of the gyro effect in general, when the optical disc 100 is out of focus, there is a change in the residual component due to the out-of-plane, so the threshold value must be set so as not to cover the change. On the other hand, the influence due to the gyro effect may show a behavior that cancels the surface blur component of the focus error signal, and as a result, it may appear rather stable. That is, it is desirable to determine the gyro effect using not only the focus error signal FE but also other signals (here, the spindle drive signal SPD).

  Therefore, by observing the spindle drive signal SPD in addition to or instead of the focus error signal FE, it is expected to suitably detect from the start of the movement of the recording apparatus 1 main body to the convergence of the gyro effect.

  Here, in observing the spindle drive signal SPD, the peak hold circuit 44 may be used. This advantage will be described with reference to FIG.

FIG. 7 is a signal diagram illustrating how the spindle drive signal SPD changes in each part for explaining the advantages of the peak hold circuit 44 according to the embodiment. Specifically, FIGS. 7A to 7D show the following signals, respectively.
FIG. 7A shows the original spindle drive signal SPD output from the spindle driver 42,
FIG. 7B shows a gyro effect detection signal in which a high frequency component is removed from the spindle drive signal SPD by the low-pass filter 43,
FIG. 7C shows a gyro effect detection signal in which the upper envelope is extracted by the peak hold circuit 44,
FIG. 7D shows a gyro effect detection signal when the eccentric component of the spindle drive signal SPD is reduced only by the low-pass filter 43 without using the peak hold circuit 44.

  Here, the gyro effect detection signal obtained in FIG. 7D needs to pass only a sufficiently low band in order to sufficiently reduce the eccentric component of the spindle drive signal SPD. The output is also slow to reflect signal changes due to the gyro effect. For this reason, compared with the gyro effect detection signal obtained in FIG. 7C, the reaction in FIG. 7D is slower, and no change reaching the threshold appears at the beginning of the gyro effect. That is, a detection delay as shown in FIG. Therefore, as shown in FIG. 7C, it is preferable to compare the maximum value of the spindle drive signal SPD from which the upper envelope is extracted with the threshold value (first threshold value).

  Subsequently, the basic operation of the recording apparatus 1 based on the above configuration will be described below.

(1-2) Operation FIG. 8 is a flowchart illustrating the basic operation of the recording apparatus 1 according to the embodiment.

  When a drive as an example of the recording apparatus 1 is turned on or the optical disk 100 is inserted into the recording apparatus 1 in a standby state, the recording apparatus 1 determines the type of the current optical disk 100 and the state of various servos. Start a general startup sequence that makes various automatic adjustments as appropriate.

  Wait until the start-up is completed and the recording apparatus 1 is in a steady state and is stabilized (step S1). When it is determined that the state of the recording apparatus 1 is steady and stable (step S1: Yes), the controller 30 starts monitoring the shock sensor 60 and various servo states (step S2). Specifically, the shock sensor 60 does not detect a predetermined shock or more regularly or irregularly, or the various servos are disconnected and cannot be controlled, or the predetermined limit is not exceeded. Is determined (step S21). If it is determined that there is no shock or servo detachment (step S21: Yes), the operation state of the recording apparatus 1 continues to monitor the shock sensor 60 and various servo states. On the other hand, when it is determined that there is a shock or servo failure (step S21: No), it is determined whether or not the recording apparatus 1 is recording (step S22). Here, if the recording is not in progress (step S22: No), adjustment of the drive state is performed so as to prevent the servo disturbance following the shock, and the return processing for adjusting again the servo that has been removed is performed. On the other hand, if recording is in progress (step S22: Yes), in order to avoid causing the medium to change in an unexpected part on the optical disc 100 by removing the servo while the recording power is output, the recording power is reduced. The emission is immediately stopped (step S23). This operation must be stopped immediately because it is impossible to control which part of the optical disk 100 will change when the servo is released, so there is a possibility of destroying already recorded data, This is because the medium of the portion that should not be recorded is changed, and the medium no longer reacts even if recording is normally performed later. Note that the processing for this shock and servo detachment is a known processing belonging to normal drive operation, and is not essential to the present plan. In addition, when a shock and a servo detachment are detected, recording stop and return processing are preferentially performed regardless of the main processing state of the present plan.

  Returning to the main processing again, the focus error signal FE generated based on the reflected light detected by the photodetector 17 and the spindle drive signal SPD for maintaining the rotation of the optical disc 100 at a predetermined speed during recording in a steady state. The level is measured (step S3). At this time, since any signal has a component synchronized with the rotation of the optical disc 100, it is desirable to perform measurement over a period of one rotation period or more of the optical disc 100. In addition, since the focus servo gain is already increased at the time when the focus error signal FE is actually compared with the second threshold, the focus servo gain is temporarily increased even during level measurement. It is desirable to measure. Note that the servo gain may not be increased at the time of measurement, and the threshold may be set in consideration of the gain change in the threshold determination step. The controller 30 sets a first threshold value of the spindle drive signal SPD and a second threshold value of the focus error signal FE. These threshold values need to be set to a level that does not erroneously detect them in consideration of components synchronized with the rotation of the optical disc 100 included in the signal. The rotation synchronization component that appears in the focus error signal FE is mainly due to the surface blur component of the optical disc 100, and the rotation synchronization component that appears in the spindle drive signal SPD is mainly an imbalance component of the optical disc 100. For this reason, the relationship between the periodic increase / decrease of the signal in the steady state and the rotation angle of the optical disc 100 is kept constant. Therefore, if the threshold value is increased / decreased in synchronization with the rotation, a more minute change can be detected. It is possible (step S4). Then, the comparator 46 determines whether or not the spindle drive signal SPD is larger than the first threshold (step S5). Here, when it is not determined that it is larger than the first threshold value (step S5: No), it is considered that the effect of the gyro effect is hardly received, so there is no need to increase or decrease the focus gain. Make a decision. On the other hand, when it is determined that the spindle drive signal SPD is larger than the first threshold value (step S5: Yes), the controller 30 controls the gain switching circuit 51 in order to suppress an increase in the residual error of the focus servo due to the gyro effect. To increase the gain of the focus servo (step S6).

  Next, it is determined whether or not the focus error signal FE is larger than a second threshold value (step S7). Here, when it is not determined that the focus error signal FE is larger than the second threshold value (step S7: No), it is still determined whether or not the spindle drive signal SPD is larger than the first threshold value (step S8). If the spindle drive signal SPD is smaller than the first threshold value at this time (step S8: No), it is considered that the influence due to the gyro effect has already disappeared, so the controller 30 operates the gain switching circuit 51 to focus. The servo gain is reduced (step S9). On the other hand, when it is determined that the spindle drive signal SPD is still larger than the first threshold (step S8: Yes), the influence of the gyro effect continues, and in order to suppress the residual error of the focus servo due to this, the focus servo The gain is kept up.

  On the other hand, when it is determined in step S7 that the focus error signal FE is larger than the second threshold (step S7: Yes), it is determined whether or not the recording apparatus 1 is recording (step S31). Here, when it is not determined that recording is in progress (step S31: No), there is no need to interrupt recording in the first place, so that the focus gain remains increased and the focus error signal FE is waited to become smaller than the second threshold ( Step S7).

  On the other hand, if it is determined that recording is in progress (step S31: Yes), the residual error of the focus servo has increased despite the fact that the gain has already been increased. Therefore, the recording is temporarily interrupted as follows. First, the controller 30 determines whether the data buffer 32 has a margin (step S32). If it is determined that there is a margin (step S32: Yes), the data sent from the host side is accumulated in the data buffer 32 even after the recording is interrupted, and waits for the effect of the gyro effect to subside. It is thought that there is room to record. Therefore, it waits until the recording unit boundary is reached (step S33). At this time, the residual error of the focus servo has increased, but this does not necessarily result in a read error. On the other hand, if the recording is interrupted when the recording unit boundary has not been reached (step S33: No), a modulation discontinuity occurs at the interruption point, resulting in a reading error, resulting in a recording unit. The recording should be interrupted after waiting for the boundary. In addition, since the servo is not off during the period of waiting for the recording unit boundary, the recording continues at the correct position on the optical disc 100, and therefore it is not necessary to stop the recording immediately. On the other hand, if it is determined that there is no room in the data buffer 32 (step S32: No), there is no room for waiting for data sent from the host, so recording is continued. In general, a device such as a camcorder is designed so that the data rate that the drive can record on a medium is sufficiently higher than the rate of data to be recorded sent from the host side. This is because data loss occurs if there is no margin in the operation on the drive side, and in particular, in the case of a camcorder, it is impossible to reproduce the lost data, that is, real-time video. When recording data from a personal computer or the like on the optical disc 100, since the original data is stored in the personal computer, the drive side notifies the host side that there is no room in the data buffer, and data transfer is performed. The interruption is generally performed. Therefore, even if there is some margin in the data buffer 32, the data transfer can be interrupted by notifying the host that there is no margin. For this reason, even if there is no margin in the data buffer 32, if recording is performed for a while, the free capacity of the data buffer 32 increases and it is determined that there is a sufficient margin (step S32: Yes). Thereafter, the recording unit boundary may be interrupted (step S33: Yes) and the recording may be interrupted (step S34).

  In the recording interruption state, the recording resumption condition is waited. As a first step, it is determined whether or not the spindle drive signal SPD is larger than the first threshold value (step S35). Here, when it is determined that the value is larger than the first threshold (step S35: Yes), it is considered that the influence due to the gyro effect that has led to the recording interruption still continues. However, even though the camcorder main body is recording, the recording apparatus 1 has stopped recording, so that data continues to be accumulated in the data buffer 32 and there is gradually no room. Therefore, it is examined whether or not the data buffer 32 still has a margin (step S36). If there is no margin (step S36: No), the recording is resumed under the condition at the time when the recording is interrupted (step S37). If there is still room in the data buffer 32 (step S36: Yes), the process returns to step S35 and waits for the disturbance to settle while interrupting the recording.

  On the other hand, when it is not determined that the spindle drive signal SPD is larger than the first threshold value (step S35: No), there is a high possibility that the influence due to the gyro effect is reduced. As a precaution, it is determined whether or not the focus error signal FE is larger than the second threshold value (step S38). If it is determined that the focus error signal FE is larger than the second threshold value (step S38: Yes), the spindle drive signal SPD has temporarily become smaller than the first threshold value or the gyro effect itself has subsided. Since there is a high possibility that the focus is disturbed due to the reverberation, the process proceeds to step S36 described above, and the recording interrupted state is maintained as long as the data buffer 32 has a margin. On the other hand, when it is not determined that it is larger than the second threshold value (step S38: No), it is considered that the disturbance has settled and is hardly affected by the gyro effect, so the controller 30 operates the gain switching circuit 51. Thus, the gain of the focus servo is reduced (step S39). Then, recording is resumed (step S40).

  According to the configuration and operation shown in the present embodiment, the optical disk is distorted due to the gyro effect, and the positional relationship between the pickup and the optical disk in the focus direction is changed. As a result, the defocus amount may increase and the recording quality may deteriorate. Even in some cases, it is possible to properly estimate the occurrence of the gyro effect and to suppress the increase in the defocus amount by increasing the gain of the focus servo as appropriate, and even if the defocus amount increases, the recording is interrupted. This makes it possible to minimize the recording of inferior quality. Further, since no special mechanical structure is required to perform this operation, there is no restriction on the size of the camcorder or the optical disk drive.

  As described above, even if the focus position relationship between the optical disk and the pickup changes due to the gyro effect without restricting the layout and steadily increasing the power consumption, the recording continues with sufficient recording quality. It is possible to provide a recording apparatus and a recording method that can be used.

  In the above description, when the spindle drive signal SPD is monitored and it is detected that there is an influence of the gyro effect, control is performed only for the gain of the focus servo, but in addition to this, other servo gains are changed. It may be. Further, in addition to or in place of the increase / decrease of the focus servo gain, it is possible to modify the skew adjustment mechanism based on the polarity of the focus error signal FE when the influence of the gyro effect is detected. In this case, if the disc center has a fixed height by a spindle but there is a focus error that causes the disc to move away from the pickup at the pickup position, it is determined that the disc itself is warped upward.

  It should be noted that the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or philosophy of the invention that can be read from the claims and the entire specification. Apparatuses and methods and computer programs are also included in the technical scope of the present invention.

1 is a block diagram conceptually showing the basic structure of a recording apparatus 1 according to an embodiment of the present invention. It is a schematic diagram which shows the relationship between the pick-up of the recording device 1 when the attitude | position of a drive is not changing based on an Example, and an optical disk. FIG. 6 is a schematic diagram illustrating a relationship between a moving direction of the recording apparatus 1 and a gyro effect when the posture is changed in the roll direction according to the embodiment. FIG. 6 is a signal diagram illustrating a focus error signal FE and a spindle drive signal SPD when the recording apparatus 1 that is actually operating according to the embodiment is moved in various directions. It is a signal diagram which shows the mode of the change of the focus error signal FE at the time of receiving the influence of the gyro effect based on an Example. It is a signal diagram which shows the mode of the spindle drive signal SPD at the time of receiving the influence of the gyro effect based on an Example. It is a signal diagram which shows the mode of the change of the detection signal obtained from the spindle drive signal SPD in each part for demonstrating the advantage of the peak hold circuit 44 based on an Example. 3 is a flowchart showing a basic operation of the recording apparatus 1 according to the embodiment of the present invention.

Explanation of symbols

1 recording device,
100 optical disc,
10 Pickup,
11 LDD (laser diode driver),
12 LD (laser diode),
13 optical system,
15 objective lens,
16 Actuator 17 Optical detector 30 Controller 31 Host interface
32 data buffers,
33 Encoder,
DESCRIPTION OF SYMBOLS 40 Amplifier circuit 41 Rotation synchronous signal detection / rotation control circuit 42 Spindle driver 43 Low pass filter 44 Peak hold circuit 50 Amplifier circuit 51 Gain switching circuit 54 Filter 56 Comparator 60 Shock sensor 70 Spindle motor 712 Clamper 711 Turntable 72 Spindle shaft

Claims (10)

A recording apparatus comprising: a focus actuator driving unit that focuses a light beam at a predetermined position of an optical disc; and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc,
A focus error signal generating means for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
Spindle drive signal generating means for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
Control means for controlling a recording operation in the recording apparatus to cope with a gyro effect generated at the time of recording based on the generated spindle drive signal in addition to or instead of the generated focus error signal. A recording apparatus. 2. The control device according to claim 1, wherein the control unit changes a focus servo characteristic in the focus actuator driving unit according to whether or not a level of the generated spindle drive signal exceeds a predetermined first threshold value. The recording device described. The control means includes
The level of the generated spindle drive signal exceeds a predetermined first threshold, and
When the level of the generated focus error signal exceeds a predetermined second threshold,
The recording apparatus according to claim 2, wherein interruption processing for interrupting recording by the recording apparatus is performed. The recording apparatus according to claim 3, wherein the control unit performs the interruption process after recording the desired data to be recorded up to a recording unit boundary of the optical disc. In detecting the level of the generated spindle drive signal,
Band limiting means for performing band limitation on the generated spindle drive signal;
5. The recording according to claim 2, further comprising an upper end holding unit that extracts an upper end envelope of the signal level subjected to the band limitation for each rotation period of the optical disc. apparatus. Measuring means for measuring the steady state levels of the focus error signal and the spindle drive signal over a period of one rotation period or more of the optical disc;
6. The apparatus according to claim 2, further comprising a setting unit configured to set at least one of the first threshold value and the second threshold value based on the measured steady state level. The recording device described. The recording apparatus according to claim 6, wherein the measurement unit measures the level of the focus error signal in the steady state in a state where a focus servo characteristic in the focus actuator driving unit is changed. The setting means sets the first threshold value and the second threshold value so as to be larger than a component synchronized with the rotation of the optical disc included in the focus error signal and the spindle drive signal measured in the steady state. The recording apparatus according to claim 6, wherein at least one of them is set. Specifying means for specifying a correspondence relationship between a periodic increase / decrease of the focus error signal and the spindle drive signal measured in the steady state and a rotation angle of the optical disc;
The threshold adjustment means for increasing or decreasing the set first or second threshold in synchronization with the rotation of the optical disk based on the specified correspondence relationship, further comprising: A recording apparatus according to claim 1. A recording method in a recording apparatus that includes a focus actuator driving unit that focuses a light beam on a predetermined position of an optical disc and a spindle driving unit that rotationally drives the optical disc, and optically records desired data on the optical disc. And
A focus error signal generating step for generating a focus error signal corresponding to a focus state of the light beam on the optical disc;
A spindle drive signal generating step for generating a spindle drive signal corresponding to the rotational speed of the optical disc;
A control step of controlling a recording operation in the recording apparatus to cope with a gyro effect generated at the time of recording based on the generated spindle drive signal in addition to or instead of the generated focus error signal. A recording method characterized by the above.

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