JPH02223024A - Method for controlling optical disk drive device - Google Patents

Abstract

PURPOSE:To eliminate the degradation of a recording medium caused by light beam and to shorten a period from the start of optical disk rotation to arrival at a normal rotating speed by making the value of a light beam output smaller than that of an output at the time of recording or reproducing when the leading-in operation of focus control is started. CONSTITUTION:When the rotating speed of an optical disk is a rotating speed V1 lower than a normal rotating speed V0 at the time of the recording or reproducing of optical information, the output of the light beam is set to an output I1 smaller than a light beam output I0 to execute the recording or reproducing and the leading-in operation of focus servo is started. When the rotating speed of the optical disk reaches the V0 and the output of the light beam reaches the I0, the optical information are recorded or reproduced after the leading-in operation of the servo is completed. Accordingly, the influence of the light beam to be given to the recording medium can be reduced and the fixed area of the rotating speed needed for the execution of the leading-in operation is eliminated. Then, the period from the start of the optical disk rotation to the arrival at the normal rotating speed can be shortened.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method of controlling an optical disc drive device for recording and reproducing an optical disc, and in particular, when a writable type optical disc is used, smooth focusing is achieved. The present invention relates to a method of controlling an optical disc drive device.

(Prior Art) In general, information recording media such as optical disks have warpage, waviness, etc. due to distortion during manufacturing and changes over time, and surface runout occurs when the information recording medium rotates. For this reason, the optical information reproducing apparatus includes a focus servo system that corrects and adjusts the distance between the information recording medium and the lens and always creates a focused state.

However, in writable optical discs, which have been attracting attention in recent years, due to the properties of the materials that make up the recording medium, if they are irradiated with a light beam for a long time in a focused state, even in the playback mode where the laser output is lower than in the record mode. There is a risk that the surface of this material will deteriorate. In particular, if the focus servo pull-in operation is started when the optical disk rotates at a low speed immediately after the rotation of the optical disk starts, the pull-in operation is fine, but the light beam spot in the focused state is relatively long between the paths of the optical disk and the track. If the recording material is sensitive, the low recording area may be severely damaged.

On the other hand, the rotation of the optical disk is at a steady rotation speed (for example, 180
If you start the focus servo pull-in operation after reaching 0 rpm), there is no risk of material surface deterioration, but the disturbance frequency to the focus servo circuit will increase due to the effects of surface runout of the disk, making this pull-in operation difficult. Become.

Taking these circumstances into consideration, the rotational speed of the optical disk is once set to a predetermined speed V1 that has not reached the above-mentioned steady rotational speed but is not low speed, and in this state, the focus servo pull-in operation is performed, and after that, the steady rotation A technique for increasing the rotational speed to speed Vo is known (Japanese Patent Application Laid-Open No. 82-15423).
Publication No. 4).

(Problem to be Solved by the Invention) However, in the above prior art, the predetermined speed V
1 cannot be set to a very low speed and it takes time to pull in the focus servo, so it is necessary to provide a certain amount of time (rotation speed - tail region) as the focus servo pull-in period. Therefore, a problem arises in that it takes a long time from the start of rotation of the optical disk until the steady rotation speed is reached.

The present invention has been made to solve these problems, and provides an optical disk drive device that can shorten the period from the start of rotation of an optical disk to a steady rotation speed without causing deterioration of the recording medium due to the light beam. The purpose of this invention is to provide a control method for

(Means for Solving the Problems) The method for controlling an optical disc drive device of the present invention is such that the rotational speed of the optical disc is set to a rotational speed ■l that is slower than the steady rotational speed V0 at which optical information is recorded or reproduced. At this time, the optical beam output is set to 11, which is smaller than the optical beam output IO necessary for recording or reproducing the optical information, and the focus servo pull-in operation is started. The rotational speed and the output of the light beam are increased gradually or all at once, and the rotational speed of the optical disk reaches the VO, the output of the light beam reaches the IO, and the retracting operation of the servo is completed. It is characterized by recording or reproducing halo information.

(Function) According to the above configuration, the rotational speed of the optical disk is set to vl, which is smaller than the steady rotational speed vo, and the output of the light beam is set to ! , the focus servo pull-in operation is started with Ii smaller than . That is,
Since the output of the light beam at the start of the focus servo pull-in operation is set to 11, which is smaller than the output used in the prior art, the influence of the light beam on the recording medium can be reduced, and therefore the above-mentioned pull-in operation It is possible to set the optical disc rotational speed at the start to a speed V1 that is lower than the steady rotational speed vo, and further lower than the rotational speed at the start of the retracting operation in the prior art. If the retracting operation can be started at such a small rotational speed (1), the retracting operation will be simple, and therefore the rotational speed-tail region required to perform the retracting operation in the prior art will be unnecessary or extremely This makes it possible to shorten the period from the start of rotation of the optical disc to the steady rotation speed.

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

FIG. 1 shows an example of an optical disk drive device for implementing the method of the present invention. That is, this device 1
A controller 2 receives a predetermined operation start command signal, and in response to the input of the command signal, sends a predetermined command signal to each part of the device based on a predetermined program, and a pickup section based on the command signal from the controller 2. 3, a laser driver 4 that sends out a predetermined laser drive current, and a speed that drives a spindle motor 6 on which a writable optical disk 5 is mounted at a rotation speed of a predetermined pattern based on command signals from the controller 2. It consists of a control circuit 7. Further, as shown in FIG. 2, this device is designed so that as the rotational speed of the optical disc 5 increases, the optical output from the semiconductor laser light source provided in the pickup section 3 increases. The laser driver 4 is configured to change the laser drive current output to the pickup section 3 based on the speed signal from the speed control circuit 7. Further, the spindle motor 6 is provided with a rotational speed detection section 8 coaxially with the motor 6, and a rotational speed detection signal from the detection section 8 is fed back to the speed control circuit 7 to perform spindle control. It is now possible to

Incidentally, in such an optical disc drive device 1, focus control is performed to focus a laser beam from a semiconductor laser light source attached to the pickup section 3 onto the optical disc 5. The timing to start this pull-in operation for focus control is such that if the rotation speed is too low, it will have a large influence on the recording medium of the optical disc 5, and if the timing is set at a steady rotation speed (for example, 1800 rpm).
), it is extremely difficult to pull in the retracting operation when the rotation speed is as high as The focus control pull-in operation was started by setting the output Io during playback. However, if the output of the laser beam is IO, its level is large, so in order to prevent the recording medium of the optical disc 5 from deteriorating, the rotational speed v2 cannot be made too low. Therefore, since the focus control pull-in operation requires a certain period of time, the pull-in operation period is a predetermined constant rotational speed period (t3- in Fig. 3 is the period numbered).
Therefore, the period from the start of rotation of the optical disk until reaching the steady rotation speed (0 in Fig. 3) is provided.
-t5 period) was long.

Therefore, in this embodiment, the pressure of the laser beam at the start of the pull-in operation for focus control is set to an output of 11, which is considerably smaller than the output IO during reproduction, so that the rotational speed V1 at the start of the pull-in operation is lower than that in the prior art. (2) It is possible to set it smaller than 2. This makes it possible to easily complete the above-mentioned retracting operation, and the predetermined rotational speed constant period (t3-t in Fig. 3) in the prior art.
Since the period 4) becomes unnecessary, it is possible to shorten the start-up period (period 0-t2 in FIG. 2) until the optical disc 5 reaches steady rotation. In this embodiment, the rotational speed of the optical disc 5 and the beam output from the laser light source increase linearly while the retracting operation for focus control is being performed and even after the retracting operation is completed. Continuing, at time t2, the rotational speed is the steady rotational speed V. In addition, when the beam output reaches the steady output IO during reproduction, each beam output is controlled to maintain that level.

After this, an operation for reproducing the optical disc will be performed.

Note that during the period in which the rotational speed and laser beam output increase, the focus servo circuit and tracking servo circuit built into the controller 2 perform compensation control that can compensate for the effects of changes in the laser beam output. will be carried out.

In the above-described embodiments, focus control when reproducing optical information has been described, but focus control when recording optical information can be similarly applied.

Furthermore, the optical disk drive device for carrying out the method of the present invention is not limited to the configuration shown in FIG.

Note that the pattern for increasing the output of the laser beam and the rotational speed of the optical disk is not limited to the one shown in FIG. 2, and various other patterns can be used. It may also be a pattern in which the value is maintained at and then increases.

(Effects of the Invention) As explained above, according to the method for controlling an optical disc drive device of the present invention, the light beam output when starting the pull-in operation for focus control is set to a value smaller than the output during recording or reproduction, Accordingly, the rotational speed of the optical disc at this time is also set to a value smaller than the steady rotational speed, so
The retracting operation described above is facilitated, and there is no need to provide a constant rotational speed period for retracting operation as in the conventional technology, so there is no deterioration of the recording medium due to the light beam, from the start of the optical disk rotation until the steady rotational speed is reached. This makes it possible to shorten the period of time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an apparatus for carrying out the method of the present invention, and FIG. 2 shows a pattern of changes in the output of the laser beam and the rotational speed of the optical disk, which are controlled by the method according to the embodiment of the present invention. Graph, FIG. 3 is a graph showing a pattern of changes in laser beam output and optical disk rotation speed controlled using a conventional method. 1... Optical disc drive device 2... Controller 4... Laser driver 6... Spindle motor 3... Pick up section 5... Optical disc 7... Speed control circuit Figure 1

Claims (1)

[Scope of Claims] A control method for an optical disc drive device that records or reproduces optical information after irradiating a light beam onto the optical disc while rotating the optical disc and pulling in a focus servo of the light beam. , when the rotational speed of the optical disc is a rotational speed V_1 slower than the steady rotational speed V_0 at which optical information is recorded or reproduced, the output of the light beam is used to record or reproduce the optical information. Required light beam output I
The focus servo pull-in operation is started by setting the output I_1 smaller than _0, and then the rotational speed of the optical disc and the output of the light beam are increased so that the rotational speed of the optical disc reaches the V_0 and this light A method for controlling an optical disk drive apparatus, characterized in that the optical information is recorded or reproduced after each beam output reaches the I_0 and the servo pull-in operation is completed.