JPH10143867A - High-speed information recording method and device for optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high speed information recording method and device for optical disk capable of forming proper bits even at the time of the high speed recording of quadruple-speed or above. SOLUTION: A laser beam having a prescribed intensity higher than a normal intensity capable of forming a bit is irradiated on an optical disk 1 by increasing the energizing current to a laser diode 9 by a signal D in the prescribed time width of the leading part of a high level in a reference digital signal A and the irradiating of the laser beam to the optical disk 1 by stopping electric conduction to the laser diode 9 by a signal H in the prescribed time width of the leading part of a low level having a time width being three-times or four-times of a reference time width suceeding the high level. As a result, a sufficient heat value is applied on the recording layer of the optical disk 1 even at the leading part of a bit forming position and the forming position of the leading shape of the but is normally formed without being delayed and, moreover, the preheat due to the laser beam irradiated on the disk at the time of the high level immediately preceeding is reduced to eliminate the delay of the but rear end part formed at the time of the high level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention mainly relates to EFM (E
The present invention relates to an improvement in recording / reproducing characteristics in high-speed information recording on an optical information recording medium such as an optical disk using a "ight to fourteen modulation" method.

[0002]

2. Description of the Related Art In recent years, a technique for recording large-capacity information on an optical information recording medium, for example, an optical disk such as a WO disk has become popular. When recording, for example, an audio signal on an optical disc, a method of digitizing and recording the audio signal at the time of recording is generally performed in order to eliminate distortion, noise, and the like at the time of reproduction. In addition, a CIRC (Cross Interleaved Reed-Solomon Code) is applied to a digitized audio signal (hereinafter, referred to as a reference digital signal).
With the addition of parity for error correction,
Further, by modulating this by the EFM method, the reproduction characteristics are improved.

[0003] By performing the above-mentioned EFM modulation, nine time widths of 3 to 11 times the predetermined reference time width T are given as the high-level and low-level time widths of the reference digital signal. The optical disk is irradiated with laser light based on the reference digital signal, and pits including pit portions and non-pit portions are formed on the recording layer. For example, during the high-level period of the reference digital signal, the recording layer is irradiated with laser light having such an intensity that the recording layer can be altered to form a pit portion.

When pits are formed by irradiating the optical disk with laser light based on a reference digital signal to dissolve or alter the recording layer and form pits, when the optical disk is irradiated with laser light, the pits are formed on the recording layer. It takes time until heat is absorbed, and it takes time to radiate the heat stored in the recording layer when the laser beam irradiation is stopped. For this reason,
The lengths of the pits and non-pits actually formed on the recording layer may not correspond to the time width of the high or low level of the reference digital signal described above, and there is a problem that the reproduction characteristics are deteriorated. Was.

That is, at the start of laser beam irradiation, the integrated value of the laser output (the amount of heat applied to the optical disk) increases, and it takes time for heat to be absorbed by the recording layer. Is formed a little later than the tip of the reference digital signal.

Further, when the laser beam irradiation is stopped, the rear end of the pit portion is formed to extend rearward due to the amount of thermal energy absorbed in the recording layer and the transmission of thermal energy. This tendency is particularly prominent when the irradiation time of the laser light is long, that is, when the temperature of the optical disk rises in proportion to the time, so that the above-mentioned time width is particularly remarkable. As a result, the width of the rear portion of the pit portion is increased, and the reflectivity is lowered and the crosstalk between tracks is deteriorated.

[0007] Since the amount of heat energy is small when the time width is short, the rear end of the pit is rarely stretched, but may be too short as compared with other pits.

Accordingly, when the length of the pits is shifted by the thermal interference between the pits, the jitter increases, and when information is recorded at a low linear velocity, for example, a linear velocity of 1.2 m / s, the aforementioned thermal interference There is a problem that the recording / reproducing characteristics are deteriorated by the influence of the above.

In order to solve the above-mentioned problems, conventionally, the high-level or low-level time width of the reference digital signal is uniformly reduced, or a high-level or low-level time width of a specific time width is conventionally used. The recording signal is generated by irradiating the optical disc with high-intensity laser light by using the recording signal, and a pit having a length corresponding to the time width of the reference digital signal and a non-pit portion is formed. Had formed.

[0010]

However, in recent years,
There is a demand for high-speed recording and reproduction of information by rotating an optical disk at a high speed of 4 times or more. In such a high-speed information recording, the thermal effect cannot be completely removed even by using the above-described means. In addition, the recording and reproducing characteristics are low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for high-speed information recording on an optical disc capable of forming appropriate pits even during high-speed recording at quadruple speed or higher, in view of the above problems.

[0012]

According to the present invention, in order to achieve the above object, according to the present invention, a period for irradiating laser light having an intensity capable of forming a pit portion while corresponding to information to be recorded is provided. A first signal level and a second signal level indicating a period during which laser light of a lower intensity is irradiated or a period during which laser light irradiation is stopped.
Is based on a reference digital signal having a time series of an arithmetic series that is 3 to 11 times the predetermined reference time width, and has a predetermined intensity for an optical disc rotating at a rotation speed of 4 times or more. In the high-speed information recording method for an optical disc, which irradiates the light to form pits on the optical disc, the intensity of the reference digital signal in a predetermined time width of a leading portion of the first signal level is higher than a normal intensity capable of forming a pit. By irradiating the optical disc with a laser beam having a high predetermined intensity, and at a predetermined time width of a leading portion of a second signal level having a time width three to four times the reference time width following the first signal level, The irradiation of the optical disk with the laser beam is stopped, and the optical disk is irradiated with a low-intensity laser beam that cannot form a pit in a second signal level portion following the time width. Suggest information high-speed recording method of the optical disk to be.

According to the information high-speed recording method for an optical disk, when information is recorded at a high speed by forming pits on an optical disk rotating at a rotation speed of 4 times or more, the head of the first digital signal level of the reference digital signal is increased. In the predetermined time width of the portion, the optical disk is irradiated with laser light having a predetermined intensity higher than a normal intensity capable of forming a pit. As a result, a sufficient amount of heat is applied to the recording layer of the optical disk even at the tip of the pit formation position, and the pit tip shape formation position is formed normally without delay.

Further, in a predetermined time width of a leading portion of a second signal level having a time width three to four times a reference time width following the first signal level, irradiation of the optical disk with laser light is stopped. In the second signal level portion following the time width, the optical disk is irradiated with a low-intensity laser beam that cannot form a pit. As a result, the residual heat due to the laser beam applied to the optical disk at the immediately preceding first signal level is reduced, the delay at the rear end of the pit formed at the first signal level is removed, and the low intensity signal is transmitted. The wobble signal recorded on the optical disk can be read by the laser light.

According to a second aspect of the present invention, a first signal level corresponding to information to be recorded and indicating a period of irradiating a laser beam having an intensity capable of forming a pit portion, and a signal having an intensity lower than the first signal level. A second signal level indicating a laser light irradiation period or a laser light irradiation stop period, wherein the first and second signal levels are 3 to 11 times a predetermined reference time width.
Based on a reference digital signal having a time width forming a double arithmetic series, a laser beam having a predetermined intensity is irradiated on an optical disk rotating at a rotation speed of 4 times or more to form pits on the optical disk. An information high-speed recording apparatus for an optical disk, a first head detecting means for detecting a first part of the first signal level in the reference digital signal and outputting a first pulse signal having a predetermined time width; Second head detection means for detecting a head portion of a second signal level having a time width three to four times the reference time width following the signal level and outputting a second pulse signal having a predetermined time width; The first pulse signal coincides with the first signal level of the first reference digital signal, and the second pulse signal is three to four times the reference time width corresponding thereto. Timing adjustment means for outputting an adjustment reference digital signal, an adjustment first pulse signal, and an adjustment second pulse signal whose timing has been adjusted so as to coincide with a leading portion of a second signal level having an interval width And an adjustment reference digital signal, an adjustment first pulse signal, and an adjustment second pulse signal, and a laser having an intensity capable of forming a pit portion when the adjustment reference digital signal is at the first signal level. Irradiating light, irradiating a laser beam having an intensity higher than the intensity while the adjustment first pulse signal is being input, and irradiating the laser beam while inputting the adjustment second pulse signal. A high-speed information recording apparatus for an optical disk including a laser beam emitting unit for completely stopping irradiation is proposed.

According to the information high-speed recording apparatus for optical discs, when pits are formed on an optical disc rotating at a rotation speed of 4 times or more and information is recorded at high speed, the first head detecting means detects the reference digital signal. A head portion of the first signal level is detected, and a first pulse signal having a predetermined time width is output.

The second head detecting means detects the head of the second signal level having a time width three to four times the reference time width following the first signal level in the reference digital signal. Thus, a second pulse signal having a predetermined time width is output.

The reference pulse signal, the first pulse signal and the second pulse signal are matched by a timing adjusting means so that the first pulse signal matches the first signal level of the reference digital signal. As
And adjusting the timing so that the second pulse signal coincides with the head of the second signal level having a time width three to four times the reference time width corresponding to the second pulse signal. First pulse signal, adjustment second
Is output as a pulse signal.

Furthermore, when the adjustment reference digital signal is at the first signal level, the laser light emitting means irradiates laser light having an intensity capable of forming a pit portion, and inputs the adjustment first pulse signal. While the laser light intensity is increased during the operation, the laser light having an intensity higher than the intensity is irradiated, and the irradiation of the laser light is completely stopped while the adjustment second pulse signal is input. .

Thus, at the leading end of the first signal level, a laser beam having a predetermined intensity higher than the normal intensity at which pits can be formed is irradiated on the optical disk. Is added to the recording layer of the optical disk, the formation position of the pit tip shape is formed normally without delay, and at the beginning of the second signal level having a time width three to four times the reference time width. Since the laser beam irradiation to the optical disk is stopped, the residual heat due to the laser beam irradiated to the optical disk at the immediately preceding first signal level is reduced,
The delay at the rear end of the pit formed at the time of the first signal level is removed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a main part configuration diagram of an optical information recording apparatus according to a first embodiment of the present invention. In the figure, reference numeral 1 denotes an optical information recording medium optical disk. As is well known, during information recording, the optical disk 1 is rotated at a high speed of 4 times or more by a spindle motor or the like (not shown).

The optical information recording apparatus includes an EFM encoder 2, a shift register 3, a PnT detector 4, an L3T detector 5, an L4T detector 6, an OR circuit 7, a laser driver 8,
And a laser diode 9.

The EFM encoder 2 EFM modulates digital information to be recorded and outputs it as a reference digital signal (A). At this time, the output reference digital signal (A) is, as shown in the timing chart of FIG.
It is composed of high-level and low-level pulse trains having a time width of 3 to 11 times the reference time width T, and is output in synchronization with a clock signal (CP) having a cycle corresponding to the reference time width T.

The shift register 3 receives a clock signal (C
It operates in synchronization with P), receives the reference digital signal (A), and outputs a signal (B) (adjustment reference digital signal) delayed by 5 clocks (CP).

As shown in FIG. 3, the PnT detection unit 4
Type flip-flops 41 and 42, a NOT circuit 43, a two-input AND circuit 44 and a shift register 45, and the flip-flops 41 and 42 and the shift register 4
5 operates in synchronization with the clock signal (CP).

The reference digital signal (A) output from the EFM encoder 2 is input to the D input terminal of the flip-flop 41. The Q output terminal of the flip-flop 41 is connected to the D input terminal of the flip-flop 42 via a NOT circuit 43. Further, the signal (A41) and the signal (A42−) output from the respective Q output terminals of the flip-flops 41 and 42 are input to the AND circuit 44, logically ANDed, and output as the signal (C).
This signal (C) is delayed by four clocks (CP) by the shift register 45 and output as a signal (D).

That is, the PnT detection section 4 detects the high-level end of the reference digital signal (A) and detects the high-level pulse signal (D) (pulse of the adjustment signal) having a pulse width of one clock (CP). 1 pulse signal). At this time, the output timing of the signal (D) coincides with the high-level head of the signal (B).

As shown in FIG. 4, the L3T detector 5 includes a shift register 51, NOT circuits 52, 53, 54, a three-input AND circuit 55, two-input AND circuits 56, 57,
And the D-type flip-flop 58, and the shift register 51 and the flip-flop 58 operate in synchronization with the clock signal (CP).

The reference digital signal (A) output from the EFM encoder 2 is input to the shift register 51 as a signal (A−) inverted by the NOT circuit 52. The QA output terminal of the shift register 51 is a NOT circuit 5
3, and connected to a first input terminal of an AND circuit 55,
Each of the output terminals QB and QC of the shift register 51 is connected to the second and third input terminals of the AND circuit 55.

The QD output terminal of the shift register 51 is connected to one input terminal of the AND circuit 54, and the QE output terminal is connected to the other input terminal of the AND circuit 54 via the NOT circuit 54. Further, an AND circuit 5
Output terminals 5 and 56 are connected to two input terminals of an AND circuit 57.

As a result, the output signal (A51) of the NOT circuit 53 and the output terminals QB and Q of the shift register 51 are output.
The output signals of C and QD (A52-, A53-,
A54-) and the output signal (A55) of the NOT circuit 54 are ANDed to output a signal (E) from the AND circuit 57. This signal (E) is delayed by one clock (CP) by flip-flop 58 and output as signal (F).

That is, the L3T detection section 5 detects a low level having a time width three times the reference time width T (hereinafter referred to as 3T time width) in the reference digital signal (A), and detects one clock (CP). ) And outputs a high-level pulse signal (E) having a pulse width of At this time, the signal (E)
Is coincident with the beginning of the low level having a 3T time width in the signal (B) corresponding to the detected low level.

As shown in FIG. 5, the L4T detector 6 comprises a shift register 61, NOT circuits 62, 63, 64, three-input AND circuits 65, 66 and a two-input AND circuit 67. Clock signal (C
It operates in synchronization with P).

The reference digital signal (A) output from the EFM encoder 2 is input to the shift register 61 as a signal (A−) inverted by the NOT circuit 62. The QA output terminal of the shift register 61 is a NOT circuit 6
3, connected to the first input terminal of the AND circuit 65,
Each of the output terminals QB and QC of the shift register 61 is connected to the second and third input terminals of the AND circuit 65.

The output terminal Q of the shift register 51
D and QE are connected to first and second input terminals of an AND circuit 66, and a QF output terminal is connected to a third input terminal of the AND circuit 66 via a NOT circuit 64. Furthermore, AN
The output terminals of the D circuits 65 and 66 are connected to the AND circuit 6
7 are connected to two input terminals.

Thus, the output signal (A61) of the NOT circuit 63 and the output terminals QB, QB of the shift register 61
C, QD, and QE output signals (A62-, A6
3-, A64-, A65-) and the output signal (A66) of the NOT circuit 64 are ANDed with a signal (G).
7 is output.

That is, the L4T detecting section 6 detects a low level having a time width four times the reference time width T (hereinafter referred to as a 4T time width) in the reference digital signal (A), and detects one clock (CP). ) And outputs a high-level pulse signal (G) having a pulse width of At this time, the signal (G)
Is coincident with the beginning of the low level having a 4T time width in the signal (B) corresponding to the detected low level.

The signal (F) output from the L3T detector 5 and the signal (G) output from the L4T detector 6 are
The logical sum is output by the R circuit 7 and output as a signal (H) (adjustment second pulse signal).

As shown in FIG. 6, the laser driving unit 8
It comprises three current sources 81, 82, 83, three switching transistors 84, 85, 86, and resistors R1 to R6.

The current source 81 is connected to the emitter of the PNP transistor 84 via a resistor R1, and the collector is connected to the anode of the laser diode 9 via a resistor R2. Also, the base of the transistor 84
The signal (H) output from the OR circuit 7 is input. As a result, the transistor 84 is turned on in a normal state in which the base potential is at a low level, energizes the laser diode 9, and is turned off when the signal (H) input to the base is at a high level. Current source 81
Then, the power supply to the laser diode 9 is stopped.

The current source 82 is connected to the collector of the NPN transistor 85 via a resistor R3, and the emitter is connected to the anode of the laser diode 9 via a resistor R4. The base of the transistor 85 has
The signal (D) output from the PnT detection unit 4 is input. As a result, the transistor 85 is turned off in the normal state in which the base potential is at the low level, stops energizing the laser diode 9 from the current source 82, and the signal (D) input to the base goes to the high level. And the laser diode 9 is energized from the current source 82.

The collector of the NPN transistor 86 is connected to a current source 83 via a resistor R5, and the emitter is connected to the anode of the laser diode 9 via a resistor R6. The base of the transistor 86 has
The signal (B) output from the shift register 3 is input. As a result, the transistor 86 is turned off when the base potential is at the low level, and the current source 8 is turned off.
Then, the current supply to the laser diode 9 is stopped, and when the signal (B) input to the base becomes a high level, the laser diode 9 is turned on, and the current source 83 supplies power to the laser diode 9.

Next, the operation of the present embodiment having the above configuration will be described with reference to the timing chart shown in FIG. The reference digital signal (A) output from the EFM encoder 3 is delayed by 5 clocks (CP) by the shift register 3 and output as a timing-adjusted signal (B).
Transistor 86 is switched. Accordingly, when the signal (B) is at a high level, the transistor 86
, A current (I3) is supplied to the laser diode 9 from the current source 83.

When the signal (B) is at the low level, the transistor 86 is turned off, and the supply of current from the current source 83 to the laser diode 9 is stopped.

Further, since the signal (H) is normally at a low level, the transistor 84 is in an on state, whereby the current (I) is supplied from the current source 81 through the transistor 84.
1) is energized to the laser diode 9. The wobble signal can be reproduced from the optical disk by emitting the laser beam by the current (I1).

Here, as an optical disk, for example, a recording layer is formed by a cyanine dye on a substrate on which a tracking group is formed, and a gold reflective layer and a protective layer made of an ultraviolet curable resin are further formed on this recording layer. An optical disk on which is formed is used. Further, when the reference digital signal A (signal B) is at a high level, the optical disk is irradiated with high intensity laser light capable of forming a pit portion, and at a low level, a low intensity laser beam capable of forming a non-pit portion. Irradiating the laser beam to the optical disk or stopping the laser beam irradiation to form pits on the recording medium.

The signal (B) has a 3T time width or 4T
When a low level having a time width is output, a signal (H) is output at the beginning of the low level, and the transistor 84 is turned off. As a result, all the three transistors 84, 85 and 86 that control the energization of the laser diode 9 are turned off, and the laser irradiation from the laser diode 9 is completely stopped for the reference time width T.

As a result, the residual heat when the pit portion is formed in the optical disk shape by the high level immediately before the low level of the 3T and 4T time widths is reduced, and the thermal effect on the formation of the subsequent non-pit portion is eliminated. Non-pit portions having a 3T and 4T time width can be reliably formed.

When a high level is output to the signal (B), the signal (D) is output at the head thereof, and the transistor 85 is turned on. As a result, the current (I2) supplied from the current source 82 via the transistor 85 to the laser diode 9 and the current (I3) supplied from the current source 83 via the transistor 86 to the laser diode 9
Is added and the current is supplied, and the intensity of the laser light from the laser diode 9 is increased by a reference time width T as compared with the normal case.

As a result, when the pit portion is formed on the optical disk, the amount of heat applied at the tip of the pit increases, so that the tip of the pit is not formed with a delay, and the time width (length) of the pit is reduced. ) Can be appropriately formed.

Therefore, according to the present embodiment, the non-pit portion having a small time width (having a 3T and 4T time width) is not formed short, and the tip of the pit portion can be formed without delay. In information recording at a high speed of 4 times or more, an appropriate pit corresponding to the reference digital signal (A) can be formed. Thereby, in high-speed information recording, high recording / reproducing characteristics can always be maintained.

Next, a second embodiment of the present invention will be described. FIG. 8 is a main part configuration diagram of an optical information recording apparatus according to the second embodiment of the present invention. In the figure, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, the difference between the first embodiment and the second embodiment is that a time width correction circuit 12 including an LnT detection unit 11 and a CPU is provided, and the time width correction of the high level and the low level of the signal (B) is performed. Is to do.

That is, the LnT detection unit 11 receives the reference digital signal A, inverts the signal (A),
The reference digital signal A is obtained by the same circuit as that of the nT detection unit.
And detects the low-level tip of the
A high-level pulse signal (J) having a pulse width of 1 minute is output.

The time width correction circuit 12 includes a shift register 3, a PnT detection unit 4, an OR circuit 7, and an LnT detection unit 1.
1 are input, and the time width of the high level and the low level of the signal (B) is adjusted to generate the signal B ′, and the signal (B) is generated. The signal (D ′) and the signal (H ′) are output by adjusting the pulse widths and timings of the signal D and the signal H in accordance with (′).

The signals (B ′, D ′, H ′) output from the time width correction circuit 12 are the signals (B, B, H) of the first embodiment.
D, H) is input to the laser drive unit 8.

Next, the operation of the second embodiment having the above configuration will be described. The reference digital signal (A) output from the EFM encoder 3 is output as a signal (B) whose timing has been adjusted by delaying 5 clocks (CP) by the shift register 3, and this signal (B) is further subjected to a time width correction circuit. After the time width between the high level and the low level is adjusted by 12, the signal is output as a signal (B ′), and the transistor 86 of the laser driving unit 8 is switched by the signal (B ′). Thus, when the signal (B ′) is at the high level, the current (I3) is supplied from the current source 83 to the laser diode 9 via the transistor 86.

When the signal (B ') is at the low level, the transistor 86 is turned off, and the supply of the current from the current source 83 to the laser diode 9 is stopped.

Further, since the signal (H ') is normally at a low level, the transistor 84 is in an ON state, whereby the current (I) is supplied from the current source 81 through the transistor 84.
1) is energized to the laser diode 9. The wobble signal can be reproduced from the optical disk by emitting the laser beam by the current (I1).

Further, when the signal B 'is at a high level, a high intensity laser beam capable of forming a pit portion is irradiated on the optical disk, and when the signal B' is at a low level, a low intensity laser beam capable of forming a non-pit portion is provided. Light is irradiated to the optical disk or laser light irradiation is stopped to form pits on the recording medium.

The signal (B ') has a 3T time width or 4
When a low level having a T time width is output, a signal (H ′) is output at the beginning of the low level, and the transistor 84 is turned off. As a result, all the three transistors 84, 85 and 86 that control the energization of the laser diode 9 are turned off, and the laser irradiation from the laser diode 9 is completely stopped for the reference time width T.

As a result, the residual heat when the pit portion is formed on the optical disk by the high level immediately before the low level of the 3T and 4T time widths is alleviated, and the thermal effect on the formation of the subsequent non-pit portion is eliminated. Non-pit portions having a 3T and 4T time width can be reliably formed.

When a high level is output as the signal (B '), the signal (D') is output at the head thereof, and the transistor 85 is turned on. As a result, the current (I2) supplied from the current source 82 via the transistor 85 to the laser diode 9 and the current (I3) supplied from the current source 83 via the transistor 86 to the laser diode 9
Is added and the current is supplied, and the intensity of the laser light from the laser diode 9 is increased by a reference time width T as compared with the normal case.

As a result, when the pit portion is formed on the optical disk, the amount of heat applied at the tip portion of the pit portion increases, so that the tip portion of the pit portion is not formed with a delay, and the time width (length) of the pit portion is long. ) Can be appropriately formed.

Further, the time widths of both the high level of the signal (B ') for forming the pit portion and the low level of the signal (B') for forming the non-pit portion are adjusted. The length of the non-pit portion is appropriately formed.

Therefore, according to the present embodiment, the non-pit portion having a small time width (having a 3T and 4T time width) is not formed short, and the tip of the pit portion can be formed without delay. Since the pit length can be appropriately formed, an appropriate pit corresponding to the reference digital signal (A) can be formed in high-speed information recording at a quadruple speed or higher. Thereby, in high-speed information recording, high recording / reproducing characteristics can always be maintained.

In this embodiment, the time width (time width of the signal D) for increasing the intensity of the laser beam in forming the tip of the pit portion and the laser beam in forming the non-pit portion tip portion having the 3T and 4T time widths. Each of the time widths for completely stopping the injection (the time width of the signal H) is set to the reference time width (T), but is not limited thereto, and is desirably set appropriately according to the type of the optical disc. .

The circuit configuration and the like in the present embodiment are merely examples, and it goes without saying that the present invention is not limited to this.

[0068]

As described above, according to the first or second aspect of the present invention, when information is recorded at high speed by forming pits on an optical disk rotating at a rotation speed of 4 times or more, the reference digital signal is used. In the predetermined time width of the head of the first signal level in the signal, the optical disk is irradiated with a laser beam having a predetermined intensity higher than a normal intensity capable of forming a pit. Is added to the recording layer of the optical disk, and the formation position of the tip shape of the pit is formed normally without delay. Further, in a predetermined time width of a leading portion of the second signal level having a time width three to four times the reference time width following the first signal level, the laser beam irradiation to the optical disc is stopped, and In the portion of the second signal level following the width, a low intensity laser beam that cannot form a pit is applied to the optical disc, so that the residual heat by the laser beam applied to the optical disc at the immediately preceding first signal level is reduced. In addition, the delay at the rear end of the pit formed at the time of the first signal level is removed, and the wobble signal recorded on the optical disc by the low intensity laser light irradiation in the second half of the second signal level is reduced. Reading becomes possible. Therefore, it is possible to form an appropriate pit corresponding to the reference digital signal in information recording at a high speed of 4 times or more,
In high-speed information recording, high recording / reproducing characteristics can always be maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an optical information recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a reference digital signal according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing details of a PnT detection unit according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram illustrating details of an L3T detection unit according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating details of an L4T detection unit according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram showing details of a laser driving unit according to the first embodiment of the present invention.

FIG. 7 is a timing chart at the time of recording information according to the first embodiment of the present invention;

FIG. 8 is a main part configuration diagram of an optical information recording apparatus showing a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... EFM encoder, 3 ... Shift register, 4 ... PnT detection part, 11 ... LnT detection part, 12
... Time width correction circuits, 41, 42 D-type flip-flops, 43 NOT circuits, 44 AND circuits, 45 shift registers, 5 L3T detectors, 51 shift registers, 52, 53, 54 NOT circuits, 55 ... 3-input A
ND circuits, 56, 57... 2-input AND circuits 56, 5
7, 58... D-type flip-flop, 6.
61: shift register, 62, 63, 64: NOT circuit, 65, 66: 3-input AND circuit, 67: 2-input A
ND circuit, 7: OR circuit, 8: Laser drive unit, 81, 8
2, 83: current source, 84, 85, 86: switching transistor, R1 to R6: resistor, 9: laser diode.

Claims (2)

[Claims] 1. A first signal level corresponding to information to be recorded and representing a period of irradiation with laser light having an intensity capable of forming a pit portion, and laser light having an intensity lower than the first signal level. And a second signal level representing a laser light irradiation stop period, wherein the first and second signal levels are represented by an arithmetic series that is 3 to 11 times a predetermined reference time width. A high-speed information recording method for an optical disc which irradiates an optical disc rotating at a rotation speed of 4 times or more with laser light of a predetermined intensity based on a reference digital signal having a time width to form pits on the optical disc. Irradiating the optical disc with laser light having a predetermined intensity higher than a normal intensity capable of forming a pit in a predetermined time width of a head portion of the first signal level in the reference digital signal; At a predetermined time width of a leading portion of a second signal level having a time width three to four times the reference time width, the laser beam irradiation to the optical disc is stopped, and a second signal following the time width is stopped. A high-speed information recording method for an optical disc, characterized by irradiating the optical disc with a low-intensity laser beam that cannot form a pit in a level portion. 2. A first signal level corresponding to the information to be recorded and representing a period of irradiating a laser beam having an intensity capable of forming a pit portion, and a laser beam having an intensity lower than the first signal level. And a second signal level representing a laser light irradiation stop period, wherein the first and second signal levels are represented by an arithmetic series that is 3 to 11 times a predetermined reference time width. A high-speed information recording apparatus for an optical disc, which irradiates a laser beam having a predetermined intensity on an optical disc rotating at a rotation speed of 4 times or more based on a reference digital signal having a time width to form pits on the optical disc. First head detecting means for detecting a first part of the first signal level in the reference digital signal and outputting a first pulse signal having a predetermined time width; and a reference time following the first signal level. 3 of width Second head detecting means for detecting a head portion of a second signal level having a time width of 4 to 4 times and outputting a second pulse signal of a predetermined time width; and wherein the first pulse signal is the reference digital signal. The first of the signal
, And the second pulse signal coincides with the head of the second signal level having a time width three to four times the reference time width corresponding thereto. Adjusting means for outputting the adjustment reference digital signal, the adjustment first pulse signal, and the adjustment second pulse signal which have been subjected to the timing adjustment of these signals, and the adjustment reference digital signal, the adjustment first pulse signal and the adjustment reference digital signal. An adjustment second pulse signal is input, and when the adjustment reference digital signal is at the first signal level, a laser beam having an intensity capable of forming a pit portion is irradiated, and the adjustment first pulse signal is input. A laser light emitting unit that irradiates a laser beam having an intensity higher than the intensity while the laser beam is being irradiated, and completely stops the laser beam irradiation while the adjustment second pulse signal is being input. A high-speed information recording device for optical disks, comprising: