JP3142096B2 - Optical drive method for optical disk device and optical disk device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optically driving an optical disk apparatus for optically recording and reproducing information, and an optical disk apparatus .

[0002]

2. Description of the Related Art In recent years, optical disk devices have been actively developed as means for recording and reproducing a large amount of data.

Hereinafter, an optical disk and an optical disk apparatus that perform tracking control by the SS (sample servo) method will be described with reference to the drawings.

FIG. 11 shows an example of a format of a conventional SS (sample servo) type phase change optical disk.
The entire circumference of the optical disk 111 is divided into a plurality of sectors 112. Each sector 112 has one address area 113
And a plurality of segments 114, and each segment 114 is divided into a servo area 115 and a recording area 116.

In the servo area 115, staggered wobble pits 118a and 118b and a clock pit 119 are formed. 117 is the center position of the track.
Reference numeral 1110 denotes a laser light spot. Light spot 11
When 10 is at the center of the track, the amount of reflected light returned at the staggered wobble pits 118a and 118b is equal.
A tracking signal can be created from the difference between the signals obtained from 118b.

The clock pit 119 is the light spot 1
The pits 110 are used to create timings for detecting the amount of reflected light when passing through the wobble pits 118a and 118b. Wobble pit 118a,
118b and the clock pit 119 are made in advance at the time of stamping.

FIG. 12 shows an example of a tracking signal detection circuit of a conventional phase change optical disk device. Light spot 1
The reproduction signal 121 obtained from the amount of reflected light when the light 110 passes is guided to the switch circuit 123. In the switch circuit 123, for example, the reproduced signal of the wobble pit 118a is guided to the sample and hold circuit 124a by the sample and hold circuit switching signal 122 generated from the reproduced signal of the clock pit 119, and the reproduced signal of the wobble pit 118b is sampled and held. It is led to the circuit 124b. The signals output from the sample and hold circuits 124a and 124b are input to a differential amplifier 125, and the tracking signal 126 is output by taking the difference between the sampled and held signals.

FIG. 13 shows a case where data is recorded in a conventional optical disk apparatus by using a servo area 115 and a recording area 116 of the optical disk 111 of FIG.
It shows the irradiation power of laser light for each area when 0 passes.

In a recording area 116, a recording power 131 necessary for changing a phase from a crystalline state to an amorphous state is used.
Then, recording is performed by modulating the laser with the binary value of the erasing power 132 (corresponding to data 1 and 0 information) necessary to change the phase from the amorphous state to the crystalline state.

In the servo area 115, the recording power 131
The laser is emitted with a reproduction power 133 having a smaller power than the power of the
10 detects the amount of reflected light when passing through the wobble pits 118a and 118b and the clock pit 119.

[0011]

However, the normal recording power 131 and the erasing power 132 are equal to the reproducing power 1.
Very large compared to 33. Generally, the recording power 131 is 15 mW to 20 mW, the erasing power 132 is about half of the recording power 131, and the reproducing power 133 is 1 mW to 2 m.
It is about W. Therefore, the region irradiated with the recording power 131 and the erasing power 132 and the region irradiated with the reproducing power 133 have significantly different thermal conditions of the phase change material.

Therefore, the above configuration has a problem that when repeated recording is performed, deterioration of the recording material starts from the beginning and end of the recording area where the thermal conditions change most rapidly on the optical disc 111.

For reference, a phase change optical disk
The mass transfer due to thermal expansion will be described. The phase-change type optical disk 111 is generally made of a glass or polycarbonate substrate, a recording film made of germanium, antimony, tellurium, etc., a dielectric protection film above and below the recording film for protecting the recording film, and a reflection film of gold or aluminum. , But the protective film absorbs less heat than the recording film. For this reason, it is considered that the recording film easily expands thermally due to heat absorption, but it is difficult to form the protective film. Therefore, when the recording film thermally expands, it is expected that the upper and lower protective films receive a force for preventing the thermal expansion of the recording film.

FIG. 14 shows this state. FIG. 14 (a)
Is a phase change optical disk 111 and its recording area 11
6 is a partial sectional view of FIG. The phase-change optical disk 111
A protective film 142 is formed on the surface of the substrate 148, a recording film 141 is formed on the surface of the protective film 142, and a protective film 142 is formed on the surface of the recording film 141.
42 is a disk-shaped optical recording medium having a reflective film 147 formed on the surface of the optical recording medium 42. FIG. 14B is an enlarged view of the recording film 141 and the protective film 142 in the cross section of the recording area 116 shown in FIG. 143 is a portion where the recording film 141 is thermally expanded. Reference numeral 145 denotes a position before the movement of the portion undergoing thermal expansion, and 146 denotes a position after the movement. 14
Reference numeral 4 denotes a force for preventing thermal expansion. In FIG. 14B, the force in the horizontal direction of the force 144 that hinders thermal expansion is on the right side in the drawing, so that the thermally expanded portion 143 moves to the right in the drawing when returning to its original size. .

As described above, when recording is repeatedly performed,
The recording film 141 due to a force 144 for preventing thermal expansion
Is slightly moved in the horizontal direction, and the deterioration starts when the amount of the recording film material is reduced by the movement .

The present invention has been made in view of the above-mentioned problems in the conventional optical disc degradation, and has been developed to provide an optical drive method and an optical disc apparatus for an optical disc apparatus capable of suppressing the deterioration of the recording material at the start and end of the recording area of the optical disc. It is intended to provide.

[0017]

[0018]

An optical disk apparatus according to the present invention.
Is an optical drive method for an optical disc apparatus that performs recording and reproduction on an optical disc having a recording area for storing data and a reproduction-only area on which control information such as control necessary for recording or reproducing the data is recorded. In the case of recording the data, all or a part of the read-only area is irradiated with light having a power larger than the power of light used for reproduction , and the irradiation is performed when the recording operation is started.
From a predetermined time before the start of recording, and / or
A method for driving an optical disk device, wherein the method is performed until a predetermined time elapses after completion of the operation.

An optical disk device according to the present invention is an optical disk for performing recording and reproduction on an optical disk having a recording area for recording data and a reproduction-only area on which control information such as control necessary for recording or reproducing the data is recorded. In the apparatus, when recording the data, the apparatus comprises light power changing means for changing the power of light for irradiating all or a part of the read-only area to light having a power larger than the power of light used for reproduction, and Optical power changing means for detecting an address from a reproduction signal obtained by reproducing the reproduction area; change signal output means for outputting a power change signal based on the detected address; It was based on the power change signal, and a power control means for controlling the power of light the irradiation, and before
The control of the power of the recording is performed at the time when the recording operation is started.
Performed before a predetermined time and / or the end of the recording operation
Thereafter, the optical disc apparatus is performed until a predetermined time has elapsed .

[0020]

[0021]

According to the present invention, when data is recorded, the optical power changing means changes the power of light for irradiating all or a part of the read-only area to light having a power larger than the power of light used for reproduction. When reproducing control information such as control necessary for recording data from the read-only area of the optical disk, the change is performed using the changed light.

[0022]

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments thereof.

FIG. 1 is a diagram showing the waveform of the irradiation power of laser light for each area in the optical disk device and the optical driving method of the optical disk device according to the first embodiment of the present invention. In FIG. 1, the optical disk has the same format as in FIG.
The servo area 115 and the recording area 116 are connected to the light spot 111.
It shows the irradiation power of laser light for each area when 0 passes.

First, in the recording area 116, data for recording binary data of a recording power 131 required to change the phase from the crystalline state to the amorphous state and an erasing power 132 required to change the phase from the amorphous state to the crystalline state. And modulates power by emitting laser.

On the other hand, in the servo area 115, a laser is emitted with a power higher than the reproducing power 133, for example, an erasing power 132, and the reflected light amount when the light spot 1110 passes through the wobble pits 118a, 118b and the clock pit 119 is measured. To detect.

As described above, when the servo area 115 is irradiated with the laser beam having the erasing power 132, the recording area 116 is irradiated.
It is possible to suppress a large change in the thermal condition between the servo region 115 and the servo region 115.

FIG. 2 is a block diagram of a tracking signal detection system of the phase change type optical disk apparatus of the above embodiment. That is, a gain switching circuit 21 that switches the gain of the reproduction signal 20 input from the servo area 115 in accordance with the gain switching signal 22 is provided in the tracking signal detection system circuit.
A tracking signal detection circuit 120 that outputs a tracking signal 126 is connected. The tracking signal detection circuit 120 outputs the sample-and-hold switching signal 12
2, a switch circuit 123 for switching an input signal according to
It comprises sample and hold circuits 124a and 124b that sample and hold the switched input signals, respectively, and a differential amplifier 125 that obtains the difference between the sampled and held signals and outputs a tracking signal 126.

As described above, the servo area 115 irradiates a laser beam with a power higher than the reproduction power 133 to obtain a servo signal as follows.

First, a reproduction signal 20 obtained from reflected light when the light spot 1110 passes is input to a gain switching circuit 21.

FIG. 3 is a block diagram showing an example of the gain switching circuit 21. The gain switching circuit 21 adjusts the level of the reproduction signal 20 from the servo area 115 at the time of recording and at the time of reproduction (the level is different from that at the time of reproduction because reproduction is performed using the erasing power 132 at the time of recording). And a circuit for switching the path.
Further, the amplifiers 35, 36 and the resistors 31, 32, 33, 3
4 constitutes an attenuator, and the gain switching signal 22
The switch circuit 37 switches.

At the time of reproduction, the contact 39 side of the switch circuit 37 is turned ON, and the reproduction signal 20 is directly output as the signal 310 through the contact 39.

On the other hand, during recording, the contact 38 side of the switch circuit 37 is turned on, attenuated by the amplifiers 35 and 36, and output as a signal 310 through the contact 38. The reason for switching the switch circuit 37 in this manner is that, as described above, since the servo area 115 is irradiated with a laser beam having a power higher than the reproduction power 133, for example, an erasing power 132, the amount of reflected light becomes larger than that during reproduction.

In this way, even if the power of the laser light to be irradiated is different between the reproduction and the reproduction, the light spot 1110 passes through the same position during the reproduction and the reproduction by the gain switching circuit 21. Sometimes a signal 310 of the same magnitude is obtained.

The signal 310 output from the gain switching circuit 21 is next input to the tracking signal detection circuit 120. In the tracking signal detection circuit 120, first, a signal 310 is input to a switch circuit 123, and a reproduction signal from a wobble pit 118 a is sampled and held by a sample and hold circuit switching signal 122 generated from a reproduction signal from a clock pit 119. The wobble pit 118 is led to the circuit 124a.
The reproduced signal from b is switched so as to be guided to the sample and hold circuit 124b.

Next, the sample and hold circuits 124a,
The output signal sampled and held at 24b is input to a differential amplifier 125, and a tracking signal 126 is obtained by calculating the difference between the inputs.

As described above, according to the present embodiment, by irradiating the servo area 115 with a laser beam having an erasing power of 132, the recording condition where the thermal condition has changed most rapidly on the optical disk when the conventional recording is repeatedly performed. Region 116
Of the recording material at the beginning and end of the recording can be suppressed.

Further, the tracking signal 126 has been described so far.
Although the description has been made by taking the example of the detection as an example, the focus area in the SS (sample servo) method and the address area in the SS (sample servo) method or the continuous groove method are generally irradiated with the laser beam of the reproduction power 133. Here, an arbitrary area (for example, an area formed with irregularities) other than the recording area to which the laser beam of the reproduction power 133 is irradiated during reproduction is referred to as a reproduction area (reproduction-only area).

In the above embodiment, it has been described that the reproduced signal 20 in the gain switching circuit 21 passes through the contact 39 as it is during reproduction, and is attenuated by the amplifiers 35 and 36 during recording to become a signal 310 from the contact 38 during recording. Instead of passing through the contact 39 as it is during recording, for example,
The same effect is obtained when the signal is amplified by the amplifiers 35 and 36 at the time of reproduction and becomes a signal 310 from the contact 38.

Further, in the above embodiment, the format of the optical disk has been described by taking the format shown in FIG. 11 as an example. However, the present invention is not limited to this, and is applicable to any rewritable optical disk having a recording area and a reproduction area adjacent to each other. Has the same effect.

FIG. 4 is a block diagram of an optical disk device according to a second embodiment of the present invention. In FIG.
Denotes an optical head for recording / reproducing on / from the optical disk 111;
Is a laser drive circuit for causing the laser of the optical head 40 to emit light. FIG. 6 shows a block diagram of the optical head 40 and the laser drive circuit 41.

In FIG. 6, reference numeral 68 denotes a laser provided on the optical head 40, and 69 denotes a light receiving element. In the laser drive circuit 41, reference numeral 65 denotes a current source for causing the laser 68 to emit light with the reproduction power 133, and reference numeral 66 denotes a current source for causing the laser 68 to emit light with the erasing power 132. At this time, the laser 68 emits light at an erasing power 132 by combining two currents flowing through the current sources 65 and 66. 67 is a laser 68
Is a current source for emitting light at the recording power 131.
At this time, the laser 68 emits light at the recording power 131 by combining three currents flowing through the current sources 65, 66, and 67.

Reference numeral 61 denotes a switch for controlling the current source 66. The switch 61 is turned on when the signal 22 rises. A switch 62 controls the current source 67. The switch 62 is turned on when the signal 411 rises.

In FIG. 4, reference numeral 42 denotes a reproducing circuit for reproducing the output from the optical head 40. The reproduction signal 20, which is the output of the reproduction circuit 42, is input to the gain switching circuit 21 as in the first embodiment, and has the same size when the light spot 1110 passes through the same position during reproduction during recording and during reproduction. Is obtained.

The signal 310 is the tracking signal detection circuit 1
20 and a tracking signal 126 is output. An address detection circuit 43 detects an address from the signal 310. A recording address detection circuit 44 detects an address of an area to be recorded.

Reference numeral 48 denotes a gain switching signal generation circuit. The gain switching signal generation circuit 48 includes, for example, AND circuits 45 and 46 and a set / reset flip-flop 47.

The address detection circuit 43 constitutes address detection means, the gain switching signal generation circuit 48 constitutes change signal output means, the laser drive circuit 41 constitutes power control means, and these address detection means , The change signal output means and the power control means constitute an optical power change means.

The gain switching signal generating circuit 48
The gain switching signal 2 is obtained from the output signal 49 of the address detection circuit 43 and the output signal 410 of the recording address detection circuit 44.
2 is output. This is shown in FIG.

FIG. 5 shows a timing chart for generating the gain switching signal 22 and the irradiation power of the laser beam for each area through which the light spot 1110 of the laser 68 passes. FIG. 5 shows a reduced number of recording areas 116 and servo areas 115 between the two address areas 113 in order to clarify the state of the laser beam irradiation power at the start of recording and at the end of recording.

In FIG. 5, reference numeral 49 denotes an address detection circuit 4.
3 is an output signal, and when an address is detected, a clock rises. Reference numeral 410 denotes an output signal of the recording address detection circuit 44. When an address to be recorded is detected, a clock is activated.

The gain switching signal 22, which is the output of the gain switching signal generating circuit 48, rises when the clock of the signal 49 and the clock of the signal 410 stand together, and then falls when only the clock of the signal 49 rises.

When the gain switching signal 22 rises, the switch of the switch circuit 37 of the gain switching circuit 21 is switched, and the switch 61 of the laser drive circuit 41 is turned on. When the recording signal 411 rises in the recording area 116 in this state, the switch 62 of the laser drive circuit 41 is turned on, and the laser 68 emits light with the recording power 131.

Reference numeral 55 denotes the irradiation power of the laser beam for each area through which the light spot 1110 of the laser 68 passes. Recording starts from the beginning of the recording area 116a. Recording area 11
At the beginning of 6a, the power rises from the reproduction power 133 to the erasing power 132 or the recording power 131 (depending on the state of the first recording signal 411 at the start of recording), and the laser 68 emits signals 22, 411 in the recording areas 116a, 116b, 116c and 116d. , And emits light at the erasing power 132 corresponding to the signal 22 in the address area 113b and the servo areas 115a and 115b.

The data recording ends at the end of the recording area 116d, but the laser beam continues to emit at the erasing power 132, and falls from the erasing power 132 to the reproducing power 133 in synchronization with the signal 22 at the end of the address area 113c. .
Therefore, the end of the recording area 116d and the address area 113c
Abrupt changes in the thermal conditions at the beginning of recording at the end of recording are suppressed.

As described above, in the optical disk apparatus of the present embodiment, the reproduction area (the servo area 115 in FIG.
a, 115b and the address areas 113b, 113c) are irradiated with a laser beam having an erasing power of 132, thereby suppressing a sudden change in thermal conditions at the beginning and end of the recording area, and at the end of the last recording area to be recorded. It is also possible to suppress a sudden change in the thermal condition at the start end of the adjacent reproduction area, and it is possible to further suppress deterioration of the optical disk.

Further, at the time of recording, when the light spot passes through the reproducing area, it is not necessary to reduce the power of the laser beam to be irradiated to the reproducing power 133.
It is only necessary to control the irradiation power with two values of the erasing power 132 and the erasing power 132, so that the recording circuit can be simplified.

In the above-described embodiment, the format of the optical disk has been described by taking the format shown in FIG. 11 as an example. However, the present invention is not limited to this, and it is applicable to any rewritable optical disk having a recording area and a reproduction area adjacent to each other. Has the same effect.

FIG. 7 is a block diagram of an optical disc device according to a third embodiment of the present invention. In FIG. 7, the configuration of the optical disk device of the present embodiment is different from that of the optical disk device of the second embodiment in that the address of the area to be recorded is replaced with the address of the area to be recorded instead of the recording address detection circuit 44 for detecting the address of the area to be recorded. An address detection circuit 71 immediately before recording for detecting the address immediately before the above, and a delay circuit 72 for delaying the gain switching signal for a predetermined time are used.

The gain switching signal generating circuit 48 outputs a signal 83 based on the output signal 49 of the address detecting circuit 43 and the output signal 82 of the immediately before recording address detecting circuit 71. The signal 83 is input to the delay circuit 72, delayed by a fixed time, and output as a gain switching signal 84.
This is shown in FIG.

FIG. 8 shows a timing chart for generating the gain switching signal 84 and the irradiation power of the laser beam for each area through which the light spot 1110 of the laser 68 passes. In FIG. 8, the numbers of the recording areas 116 and the servo areas 115 between the two address areas 113 are reduced in order to clarify the state of the irradiation power of the laser beam at the start of recording and at the end of recording.

In FIG. 8, reference numeral 49 denotes an address detection circuit 4.
3 is an output signal, and a clock rises every time an address is detected. Reference numeral 82 denotes an output signal of the address detection circuit 71 immediately before recording. When an address immediately before an address to be recorded is detected, a clock is raised. Reference numeral 83 denotes an output of the gain switching signal generating circuit 48, which rises when the clock of the signal 49 and the clock of the signal 82 stand together, and falls when the clock of the signal 49 only rises next.

The signal 83 is input to the delay circuit 72 and is delayed by a predetermined time to become a gain switching signal 84. The delay time at this time is set so that the gain switching signal 84 rises in the middle of the address area.

When the gain switching signal 84 rises,
The switch of the switch circuit 37 of the gain switching circuit 21 is switched, and the switch 61 of the laser drive circuit 41 is switched.
Is turned on, and the laser 68 emits light with the erasing power 132. When the recording signal 411 rises in the recording area 116 in this state, the switch 62 of the laser drive circuit 41 is turned on, and the laser 68 emits light with the recording power 131.

Reference numeral 85 denotes the irradiation power of the laser beam for each area through which the light spot 1110 of the laser 68 passes. Recording starts from the beginning of the recording area 116a, but the power of the laser beam rises from the reproducing power 133 to the erasing power 132 in the middle of the address area 113a in synchronization with the signal 84, and the laser 68 emits the recording areas 116a, 116b, 1
In 16c and 116d, light is emitted with two values of the recording power 131 and the erasing power 132 corresponding to the signals 84 and 411, and in the address area 113b and the servo areas 115a and 115b, light is emitted with the erasing power 132 corresponding to the signal 84.

The recording ends at the end of the recording area 116d, but the laser beam continues to emit at the erasing power 132, and the erasing power 1 is synchronized with the signal 84 in the middle of the address area 113c.
From 32, the reproduction power 133 falls.

Accordingly, the address area 113 at the start of recording is
There is no sudden change in the thermal conditions at the end of a and the beginning of the recording area 116a, and there is no sudden change in the thermal conditions at the end of the recording area 116d and the beginning of the address area 113c at the end of the recording operation.

As described above, in the optical disk apparatus of this embodiment, the recording area is irradiated with the laser beam of the erasing power 132 during recording, thereby suppressing a sudden change in the thermal condition at the start and end of the recording area, and It is possible to suppress a sudden change in thermal conditions at the end of the reproduction area immediately before the start of the recording operation and the beginning of the next recording area, and at the end of the last recording area to be recorded and the beginning of the next reproduction area. Thus, deterioration of the optical disk can be further suppressed.

In the above embodiment, the format of the optical disk has been described by taking the format shown in FIG. 11 as an example. However, the present invention is not limited to this, and is applicable to any rewritable optical disk having a recording area and a reproduction area adjacent to each other. Has the same effect.

In each of the above embodiments, the servo area 115 is irradiated with the laser beam at the erasing power 132. However, the present invention is not limited to this, and the laser beam with an arbitrary power higher than the reproducing power 133 is irradiated. You may do so.

In each of the above embodiments, the servo area 115 has been described as an example of the reproduction area. However, the present invention is not limited to this, and may be applied to an arbitrary reproduction area other than the recording area as described above.

In each of the above embodiments, the reproduction by the erasing power 132 at the time of recording is performed for the entire reproduction area and the entire period of each reproduction area. However, the present invention is not limited to this. Alternatively, reproduction may be performed by the erasing power 132 only during a part of the period near the start and end of the reproduction area.

FIG. 9 is a schematic diagram showing the conventional technique described with reference to the related art section.
Light related to the present invention solves the disadvantages of conventional optical discs
FIG. 3 is a diagram illustrating an example of a format of a disc . That is, the entire circumference of the optical disc 91 is divided into a plurality of sectors 92, and each sector 92 has one address area 113,
It is divided into a plurality of segments 94. Each segment 9
4 is divided into a servo area 95 and a recording area 116.

In the servo area 95, staggered wobble pits 118a and 118b and a clock pit 119 are formed in the same manner as in the conventional example, and pre-pits 96a and 96b irrelevant to servo information are formed at both ends of the servo area 95.
Are formed. These wobble pits 118a,
118b, clock pit 119, pre-pit 96a,
96b is made in advance at the time of stamping.
Reference numeral 117 denotes a center position of the track, and reference numeral 1110 denotes a light spot.

FIG. 10 is an enlarged cross-sectional view and a top view of a part of the optical disk near the prepits 96a and 96b. The recording area 116 is on the left side (on the drawing) of the pre-pit 96a and on the right side (on the drawing) of the pre-pit 96b. Right side of pre-pit 96a (on the drawing) and pre-pit 96b
(On the drawing) is a servo area 95.

First, when recording is repeatedly performed in the recording area 116, the recording film 141 repeats expansion and contraction due to heat. Since the protective film 142 has a smaller heat absorption than the recording film 141, it is difficult for the protective film 142 to thermally expand.
2 receives a force 101a or 101b from the protective film 142 that hinders thermal expansion.

Next, the force 1010a of the horizontal component of the force 101a that hinders thermal expansion is transmitted through the recording film and finally transmitted to the portion immediately to the left of the prepit 96a, and further attempts to move rightward. Is a barrier, and movement is suppressed.

Further, the force 1010b of the horizontal component of the force 101b that hinders thermal expansion is transmitted through the recording film and finally transmitted to the portion immediately to the right of the prepit 96b, and further attempts to move to the left. It acts as a barrier and restrains movement.

As described above, by providing the pre-pits 96a and 96b irrelevant to the servo information outside the recording area 116, the pre-pits 96a and 96b act as barriers to prevent the recording film material from being repeatedly recorded. Movement can be suppressed.

In the above example, circular pre-pits 96a and 96b are provided at the end of the servo area 95 to suppress the movement of the recording film material as the recording material. However, the present invention is not limited to this.
For example, it may have another shape such as a quadrangle, in other words, the protective film may be bent so as to suppress the movement of the recording material.

In the above example, the pre-pits 96a, 96
Although 6b is provided at the extreme end of the servo area 95, the present invention is not limited to this, and any location outside the recording area may be used as long as the movement of the recording material can be suppressed.

[0081]

As is apparent from the above description, in the present invention, when data is recorded, the power of light for irradiating all or a part of the read-only area is set to a power larger than the power of light used for reproduction. Since the light is changed to light, there is an advantage that deterioration of the recording material at the beginning and end of the recording area of the optical disk can be suppressed.

[0082]

[Brief description of the drawings]

FIG. 1 is a diagram showing a waveform of an irradiation power of a laser beam for each area in an optical disc device and an optical driving method thereof according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a tracking signal detection system of the optical disc device of the embodiment.

FIG. 3 is a block diagram of a gain switching circuit of the optical disc device of the embodiment.

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

FIG. 5 is a timing chart in the embodiment.

FIG. 6 is a block diagram of a laser drive circuit and an optical head of the optical disc device of the embodiment.

FIG. 7 is a block diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 8 is a timing chart in the embodiment.

FIG. 9 is a diagram showing an example of a format of an optical disc related to the present invention.

FIG. 10 is a diagram illustrating thermal expansion of a recording film of the same example .

FIG. 11 is a diagram showing an example of a format of a conventional optical disc.

FIG. 12 is a block diagram of a tracking signal detection circuit of a conventional optical disc device.

FIG. 13 is a diagram showing a waveform of irradiation power of laser light for each area in a conventional optical disc device.

FIG. 14A is a partial cross-sectional view of a conventional optical disk, and FIG. 14B is an enlarged view of the cross-section.

[Explanation of symbols]

 Reference Signs List 20 reproduction signal 21 gain switching circuit 22 gain switching signal 37 switch circuit 40 optical head 41 laser drive circuit 42 reproduction circuit 43 address detection circuit 44 recording address detection circuit 48 gain switching signal generation circuit 71 address detection circuit immediately before recording 72 delay circuit 91 optical disk 92 sector 94 segment 95 servo area 96 prepit 111 optical disk 112 sector 113 address area 114 segment 115 servo area 116 recording area 131 recording power 132 erasing power 133 reproduction power 141 recording film 142 protective film

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takashi Ishida 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In company

Claims (3)

(57) [Claims] 1. An optical drive method for an optical disk apparatus for performing recording and reproduction on an optical disk having a recording area for storing data and a reproduction-only area in which control information such as control necessary for recording or reproducing the data is recorded. In the case of recording the data, the entire or a part of the read-only area is irradiated with light having a power larger than the power of light used for reproduction, and the irradiation is performed for a predetermined time at a time when the recording operation is started. An optical drive method for an optical disk device, wherein the method is performed before and / or after a predetermined time elapses after the end of the recording operation. 2. The method according to claim 1, wherein the light having a power higher than the power of the light used for reproduction is an erasing power used for the recording operation. 3. An optical disc apparatus for recording / reproducing on / from an optical disc having a recording area for recording data and a reproduction-only area in which control information such as control necessary for recording or reproducing the data is recorded. When recording, the optical power changing means for changing the power of light for irradiating all or a part of the read-only area to light having a power larger than the power of light used for reproduction, and the optical power changing means, Address detection means for detecting an address from a reproduction signal obtained by reproducing the reproduction area; change signal output means for outputting a power change signal based on the detected address; Power control means for controlling the power of the irradiated light, and the control of the power of the light starts the recording operation. Performed from a predetermined time before the time, and /
Alternatively, the optical disc device is characterized in that the recording operation is performed until a predetermined time has elapsed after the end of the recording operation.