JPS63104221A - Optical disk driver - Google Patents

Abstract

PURPOSE:To prevent the destruction of recorded information by stopping the radiation of a laser light beam by a head until the next access request is received when it is detected that the duration time of the idle state exceeds a limit value thereby suppressing the reduction in a mean access speed. CONSTITUTION:Since an output signal 30 of an idle state detection circuit 26 goes to an L level in case of the idle state, a timer 28 is operated. If the operating time of the timer 28 exceeds a prescribed time, an output signal 31 of the timer 28 changes to an H level, resulting that an FF32 is changed to the set state and an output signal 33 goes to an H level. As a result, a control section 20 stops the operation of a laser light source 14 to stop the radiation f the laser light beam. When the access request comes, the signal 31 goes to an L level and the signal 30 goes to an H level, the FF32 is set and the signal 33 goes to an L level. The control section 20 controls a light source 14 to as to bring the intensity of the radiated laser light beam to be a prescribed intensity for information recording or reproduction.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical disc drive.

[Prior Art] In a conventional optical disc drive (optical disc drive), information is recorded based on the intensity of a laser beam irradiated onto an optical disc during an idle state, that is, a state in which neither information is reproduced nor recorded. It is made to be sufficiently weaker than during playback.

[Problem to be Solved] The intensity of the laser beam in the idle state is sufficiently weaker than that during information reproduction (naturally, than when information is recorded).

However, if the idle state continues for a long time, the same track on the optical disk is repeatedly irradiated with a laser beam, and as a result, the surface temperature of that track gradually increases. It has been found that when the duration of the idle state exceeds a certain limit, problems occur such as the recorded information of the track is destroyed or meaningless information is recorded.

In order to prevent the destruction of recorded information or the recording of meaningless information in such an idle state, the intensity of the laser beam in the idle state may be further weakened. However, if the intensity of the laser beam in the idle state is increased too much, when an access request is received later, the laser beam will be increased to a predetermined intensity that enables recording and regeneration to make access possible. This increases the time it takes to access the network, leading to a decrease in average access speed. Therefore, conventionally, there is a limit to reducing the intensity of a laser beam in an idle state.

[Object of the Invention] Therefore, an object of the present invention is to provide an optical disk drive device that prevents destruction of recorded information or erroneous recording of information in an idle state while minimizing a decrease in average access speed. be.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a means for monitoring the duration of an idle state in an optical disk drive, and a means for monitoring the duration of an idle state when the duration exceeds a limit value in an optical disk drive. means for stopping irradiation of the laser beam by the head until the next access request is received when the access request is detected.

[Operation When the co-idle state exceeds the limit value, that is, if the laser beam continues to be irradiated, the information recorded on the optical disc will be destroyed, the laser beam irradiation is stopped. Therefore, destruction of recorded information on the optical disc can be prevented.

Also, when the laser light beam irradiation is stopped (actually, the drive of the laser light source is turned off), it takes a considerable amount of time to increase the intensity of the laser light beam to a level that allows information to be reproduced or recorded. A long time will be required. However, instead of unconditionally stopping the laser beam irradiation in the idle state, the laser beam irradiation is stopped when the duration of the idle state exceeds a limit value that may cause the destruction of recorded information. The frequency of this is very low. Therefore, such a decrease in the average access speed due to the stoppage of irradiation of the laser beam hardly poses a problem.

On the contrary, since there is no need to worry about the destruction of recorded information due to continued idle state, it is possible to make the irradiation laser beam stronger than before until the idle state reaches the limit time, and the laser light beam can be increased by that amount. There is also the possibility that the average access speed can be increased by significantly shortening the verification time.

[Example 1] An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing a simplified functional configuration of an embodiment according to the present invention.

In this figure, lO is the head, and the optical disk 12
Laser light source 1 for irradiating a laser light beam onto the surface of
4 and a light receiving element 16 for detecting the reflected light of the laser beam from the surface of the optical disk 12.

Reference numeral 18 denotes a head access control section comprising a mechanism and a control circuit for moving and positioning the head 10 in the radial direction of the optical disk 12. This head access control section 1
8 is controlled by the control unit 20.

A head control section 22 includes a drive circuit for the laser light source 14, an amplification circuit for a detection signal (read information signal) from the light receiving element 16, and the like. Between the head control section 22 and the control section 20, read information signals, write information signals, control signals for the laser light source 14 in an idle state, which will be described later, and the like are exchanged.

24 is a bus for exchanging signals with a host computer (not shown).

25 is an idle state duration monitoring section. The idle state duration monitoring section 25 includes an idle state detection circuit 26 that detects an idle state based on the presence or absence of an address signal on the bus 24, and a timer 28.

During access, the output signal 3 of the idle state detection circuit 25
0 is maintained at H level, but in the idle state, the output signal 30 becomes L level. The timer 28 outputs the output signal 30
It is activated when the signal becomes L level, and when the operating time exceeds a predetermined time, the output signal 31 is set to H level. Furthermore, when the signal 30 becomes H level, the timer 28 is reset and stopped 1-
Then, the output signal 31 becomes L level.

32 is a flip-flop for controlling the operation stop of the laser light source 14. A signal 31 is applied to the set input of this flip-flop 32, and a signal 30 is applied to the reset input.
is given. The output signal 33 of the flip-flop 32 is given to the control unit 20 as a laser beam irradiation stop instruction signal.

Next, operations related to controlling the intensity of the irradiated laser beam in the idle state will be described.

In the idle state, the control unit 20 controls the driving conditions of the laser light source 14 through the head control unit 20 so that the intensity of the irradiated laser beam becomes a predetermined level weaker than that during information reading.

At this time, the output signal 30 of the idle state detection circuit 26 is L.
Since the level is reached, the timer 28 operates. Note that since the flip-flop 32 is reset every time an access request is made, it is in a reset state at this point.

If an access request is received before the operating time of the timer 28 reaches a predetermined time, the signal 30 goes high and the timer 28 stops, so its output signal 31 remains at the low level. Further, the control section 20 controls the driving conditions of the laser light source 14 so that the intensity of the laser light beam reaches a predetermined intensity necessary for reading information.

On the other hand, when the timer 28 operates in an idle state and the operating time exceeds a predetermined time, that is, when the duration of the idle state exceeds a predetermined time (limit value), the timer 28 starts operating.
The output signal 31 changes to H level, thereby changing the flip-flop 32 to the set state, and the output signal 33 changes to H level.

As a result, the control unit 20 stops the operation of the laser light source 14 L:, and stops the irradiation of the laser light beam L:.

In this manner, when the idle state exceeds the limit time, the irradiation of the laser beam is stopped from that point on.

Therefore, the recorded information on the optical disc 12 will not be destroyed or meaningless information will not be recorded during the idle state.

After that, when there is a stable access, the output signal 31 of the timer 31 becomes L level, and the idle state P! Detection circuit 2
Since the output signal 30 of 6 becomes H level, the flip-flop 32 becomes a reset state, and its output signal 33 becomes L level.
level.

The control unit 20 immediately controls the laser light source 14 so that the intensity of the irradiated laser beam reaches a predetermined intensity for recording or reproducing information from the time of the access request, but until the intensity reaches the predetermined intensity, Access operations are made to wait.

As described above, once the irradiation of the laser beam is stopped, a relatively long time is required until the intensity of the irradiated laser beam is returned to a predetermined intensity for reproducing or recording information. However, since the frequency of being in an idle state for such a long period of time that the laser beam irradiation is stopped is low, a decrease in the average access speed due to the waiting time is not a problem.

Rather, since it is possible to set the intensity of the laser beam in the idle state higher than in the conventional case, the access speed can be improved.

Although one embodiment has been described above, the present invention is not limited thereto, and can be implemented with various modifications within the scope of the invention.

[Effects of the Invention] 2 As explained above, the present invention provides means for monitoring the duration of an idle state, and when it is detected by this means that the duration exceeds a limit value, the next access is The head has means for stopping the laser beam irradiation by the head until a request is received, and if the idle state exceeds a limit value, that is, if the laser beam continues to be irradiated, the information recorded on the optical disk may be destroyed. In such a case, since the irradiation of the laser beam is stopped, destruction of recorded information on the optical disc can be prevented.

Since the frequency of stopping the laser beam irradiation is quite low, a decrease in the average access speed due to the stopping of the laser beam irradiation hardly poses a problem.

On the contrary, since there is no need to worry about the destruction of recorded information due to continued idle state, it is possible to make the irradiation laser beam stronger than before until the idle state reaches the limit time, and the laser light beam can be increased by that amount. It may also be possible to shorten the time required for startup and increase average access speeds.

As described above, according to the present invention, it is possible to realize an optical disk drive device that prevents destruction of recorded information in an idle state without causing a decrease in average access speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a simplified configuration of an embodiment of an optical disk drive 8A according to the present invention. 10...Head, 12...Optical disk, 14...
Laser light source, 16... Light receiving element, 20... Head control unit, 20... Control unit, 25... Idle state duration monitoring cap, 32... Flip-flop.

Claims (1)

[Claims] (1) In an optical disk drive device that irradiates an optical disk with a laser beam using a head and reads recorded information from the reflected light, there is a means for monitoring the duration of an idle state, and a means for monitoring the duration of an idle state when the duration exceeds a limit value. 1. An optical disk drive apparatus comprising: means for stopping irradiation of a laser beam by the head when a next access request is detected.