JP2702018B2 - Optical information recording method and device therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention mainly relates to EFM (Eight
The present invention relates to a method and apparatus for recording information on an optical information recording medium such as an optical disk using a 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 a pit portion is formed on the recording layer. For example, laser light having an intensity capable of forming a pit portion is irradiated during a high level period of the reference digital signal.

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, as shown in FIG. 2, at the start of laser light irradiation, the integrated value of the laser output increases and it takes time for heat to be absorbed by the recording layer. The leading end is formed slightly later than the leading end of the reference digital signal A.

Further, when the laser beam irradiation is stopped, the rear end of the pit Pa is formed rearward by the amount of heat energy absorbed in the recording layer and the transmission of the heat energy. This tendency is observed when the irradiation time of laser light is long.
That is, since the temperature of the optical disk rises in proportion to time,
This is particularly noticeable when the time width is large. In this case, the shape of the pit Pa becomes a tear shape, the width of the rear portion of the pit becomes wide, the reflectance decreases, and the crosstalk between tracks deteriorates. Invite.

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

Accordingly, there has been a problem that the deviation of the length of the pits Pa caused by thermal interference between the pits Pa causes an increase in jitter and a deterioration in recording / reproducing characteristics.

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

[0010]

However, even if the above-mentioned means were used, the thermal effect could not be completely removed, and the recording / reproducing characteristics were low. This is because the time width of the high level or the low level of the reference digital signal was uniformly corrected, and the influence of thermal interference between the pit portions was not considered. As a result, the lengths of the pit portion and the non-pit portion having a short length do not correspond to the time width of the high level and the low level of the reference digital signal. In particular, the length of a pit portion and a non-pit portion corresponding to a minimum time width following a short pit portion and a non-pit portion, that is, a time width three times the reference time width (hereinafter referred to as a 3T time width) is a reference. It does not correspond to the time width of the digital signal.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an optical information recording method and apparatus for recording information in consideration of the influence of thermal interference during recording.

[0012]

According to claim 1 of the present invention,
A first signal level corresponding to the information to be recorded and representing a period of irradiating laser light having an intensity capable of forming a pit portion, and a period or a laser beam of irradiating laser light having an intensity lower than the first signal level. A second signal level indicating a period during which the light is stopped, and wherein the first and second signal levels have a time width forming an arithmetic series that is an integral multiple of a predetermined reference time width. In the optical information recording method of forming a pit by irradiating the optical information recording medium with laser light of a predetermined intensity on the basis of the reference digital signal, a step of reproducing the information after tentatively recorded information using laser light intensity different to the test area of the information recording medium, repeated multiple times, Le - with determining the proper light intensity the said Record laser light with proper light intensity Detecting the reflected light intensity of the reproduction laser light from the pits formed as a test using as, reproducing the information recorded on the optical information recording medium as a digital signal based on the reflected light intensity; A high-level or low-level time width of the reproduced digital signal is detected, and a time included in the reference time width centered on a comparison time width of a time width of a predetermined length or less from the time width. After extracting the width, the time width is compared with the comparison target time width, and based on the comparison result, at least the high level or the low level of the reproduction digital signal is set so that these time widths become equal. An increase / decrease value of the time width of the signal level of the reference digital signal corresponding to and having the time width of the comparison target is obtained, and at the time of information recording, the increase / decrease value is used and the reference The time width of the signal level of the digital signal to generate a recording signal corrected, Le to the optical information recording medium by the recording signal - is irradiated with laser light to propose an optical information recording method for forming pits.

According to a second aspect of the present invention, a first signal level corresponding to information to be recorded and representing a period of irradiating laser light having an intensity capable of forming a pit portion and a laser having an intensity lower than the first signal level. A second signal level representing a period during which laser light is irradiated or a period during which laser light irradiation is stopped, wherein the first and second signal levels have a time width that is an integral multiple of a predetermined reference time width. Based on the reference digital signal, the optical information recording medium is irradiated with laser light of a predetermined intensity to form a pit, and the intensity of light reflected from the optical information recording medium is detected in an optical information recording apparatus. Light intensity detecting means, signal reproducing means for reproducing information recorded on the optical information recording medium as a digital signal based on the detection result of the light intensity detecting means, and high level of the digital signal reproduced by the signal reproducing means. level Or a time width detecting means for detecting a low-level time width, and from the time widths detected by the time width detecting means, the reference time centered around a time width to be compared having a time width equal to or less than a predetermined length. A time width extracting means for extracting a time width included in the time width; a time width comparing means for comparing the time width extracted by the time width extracting means with the comparison target time width; and a signal reproduced by the signal reproducing means. Di
The time width of the digital signal is an integral multiple of the reference time width.
Thus, a correction value selection table in which correction values obtained by experiments are set in advance for correcting the time width of the reference digital signal, and a comparison result between the correction value selection table and the time width comparison means. On the basis of the time width extracting means,
The extracted time width is not equal to the comparison target time width.
In so that at least the reproduction high level or b digital signal - and corresponding to the level, and the correction time width selecting means for determining the increase or decrease value of the time width of the signal level of the reference digital signal having the comparison target time width, Recording signal generating means for generating a recording signal in which the time width of each signal level in the reference digital signal is corrected using the increase / decrease value selected by the correction time width selecting means; An optical information recording device provided with a laser drive control means for controlling the drive of the laser is proposed.

[0014]

According to the first aspect of the present invention, before formal recording of information, information is experimentally recorded on a test area of an optical information recording medium using a plurality of different laser beam intensities based on a reference digital signal. a step of reproducing the information after recording is repeated multiple times, Le - obtaining a proper light intensity of the. further,
The reflected light intensity of the reproducing laser light from the pit formed experimentally using the laser light having the proper light intensity as the recording light is detected, and the optical information recording medium is recorded on the optical information recording medium based on the reflected light intensity. The recorded information is reproduced as a digital signal, a high-level or low-level time width of the reproduced digital signal is detected, and a time width to be compared with a time width of a predetermined length or less from the time width is detected. , And extracts a time width included in the reference time width. Thereafter, the time width is compared with the time width to be compared, and based on the comparison result, at least the high level or low level of the reproduced digital signal is set so that the time widths become equal.
An increase / decrease value of the time width of the signal level of the reference digital signal corresponding to the level and having the comparison target time width is obtained. At the time of formal recording of information, a recording signal in which the time width of the signal level of the reference digital signal is corrected using the increase / decrease value is generated, and the optical information recording medium is irradiated with laser light by the recording signal. Pits are formed.

According to the present invention, when test recording and reproduction of information on the optical information recording medium is performed, the intensity of the reflected light from the optical information recording medium is detected by the light intensity detecting means. Based on the detection result, the information recorded on the optical information recording medium is reproduced as a digital signal by the signal reproducing means. Further, a time width detecting circuit detects a high-level or low-level time width of the digital signal reproduced by the signal reproducing means, and from the time width, the time width extracting means detects a time width equal to or less than a predetermined length. The time width included in the reference time width is extracted with the comparison target time width of the time width as the center. Further, the time width extracted by the time width extracting means is compared with the comparison target time width by the time width comparing means, and based on the correction value selection table in which the correction value obtained in advance is set and the comparison result. The correction time width selection means allows the time width extraction means
The extracted time width is equal to the comparison target time width
Thus, an increase / decrease value of the time width of the signal level of the reference digital signal corresponding to at least the high level or the low level of the reproduction digital signal and having the comparison target time width is obtained. Thereafter, when formal information recording is performed, the recording signal generation means corrects the time width of each signal level in the reference digital signal by using the increase / decrease value selected by the correction time width selection means. A signal is generated, and the driving of the laser is controlled by the laser driving control means based on the recording signal, and a pit is formed on the optical information recording medium.

[0016]

FIG. 1 is a block diagram of an optical information recording apparatus showing one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an optical information recording medium optical disk. As is well known, during information recording, the optical disk 1 is rotated by a spindle motor or the like (not shown).

Further, the optical information recording device includes a signal conversion unit 2,
Time width detection unit 3, main control unit 5, display unit 6, switch unit 7
And a recording unit 8.

The signal conversion unit 2 includes an optical pickup 21, R
F amplifier 22, AC coupling 23, inverter 24, 1
The circuit comprises an analog switch 25 having two contacts and a comparator 26. The optical pickup 21 is
The optical disk 1 is composed of a laser diode, a phototransistor, and the like. The optical disk 1 is irradiated with laser light, receives reflected light from the optical disk 1, and outputs a voltage proportional to the light intensity. The RF amplifier 22 outputs a signal RF obtained by amplifying the output signal of the optical pickup 21. This signal RF is AC
After being converted into a signal RF1 by the coupling 23, the signal RF1 is input to the inverter 24 and the first contact 25a of the analog switch 25.

The inverter 24 inputs a signal RF2 obtained by inverting the polarity of the input signal RF1 to a second contact 25b of the analog switch 25. Contact piece 2 of analog switch 25
5c is connected to the first or second contact 25a, 25b by a switching signal SEL from the main control unit 5, and the signal RF1 or the signal RF2 output from the contact piece 25c is
The data is input to the comparator 26. The comparator 26 is
The input signal RF1 or RF2 is compared with a predetermined threshold voltage, converted into a digital signal RD having a TTL level voltage, for example, and output.

The time width detector 3 includes a D-type flip-flop 31, a NOT circuit 32, a 16-bit counter 33,
It is constituted by latch circuits 34 and 35, comparison circuits 36 and 37, and a three-input AND circuit 38, detects a high-level time width in the signal RD, and sets the detected time width in advance by the main control unit 5. The data of this time width is output when it is within the predetermined allowable range.

That is, the signal RD output from the comparator 26 is input to the data input terminal D of the flip-flop 31, and the clock signal C is input to the clock input terminal CLK.
K has been entered. The clock signal CK has, for example, a cycle of １ ／ of the reference time width T of the reference digital signal A described above. The signal RD1 output from the data output terminal Q of the flip-flop 31
Are the enable terminal E and the clear terminal C of the counter 33.
The signal LR is input to the first input terminal of the AND circuit 38, and is input to the latch circuit 34 as a signal RD2 inverted by the NOT circuit 32.

Clock signal input terminal CL of counter 33
The clock signal CK is input to K, the counter 33 performs a counting operation while the signal RD1 is at a high level, and the signal RD
When 1 goes low , it is cleared and operation stops.
16-bit data DA1 output from the counter 33
Are input to the latch circuit 34. Latch circuit 34
Latches the input data DA1 at the rising edge of the signal RD2 and outputs the latched data DA2 to the latch circuit 35 and the comparison circuits 36 and 37.

The comparison circuit 36 has a 16-bit data D set in advance by the main control unit 5 via the data bus DB.
A11 is compared with data DA2, and when the value of data DA2 is smaller than the value of data DA11, output signal WD is set to high level. Further, the comparison circuit 37 is provided in advance by the main control unit 5.
Compares the 16-bit data DA12 set via the data bus DB with the data DA2, and outputs the data DA2
Is higher than the value of the data DA12, the output signal WU is set to the high level. These signals WD and WU are ANDed with the signal RD by the AND circuit 38, and the output signal WI of the AND circuit 38 is set to the high level when the signals WD, WU and the signal RD are both at the high level, and is input to the latch circuit 35. Is done. The latch circuit 35 inputs data DA when the signal WI changes from low level to high level.
2 and outputs the latched data DA3 to the main controller 5.

Thus, the time width detector 3 outputs the value of the time width only when the high level time width of the signal RD is larger than the data DA12 and smaller than the data DA11. It is output to the main control unit 5 as DA3.

The main control unit 5 is constituted by a CPU or the like, controls the display of the display unit 6, and controls the driving of each unit based on the switch operation of the switch unit 7. Also,
The main control unit 5 outputs the signal WI and the output data of the latch circuit 35.
The data DA3 is read, based on which the arithmetic processing described later is performed, and the correction data DAT is output to a recording signal generation circuit described later. The switch unit 7 includes a recording switch and a data switch.
And a momentary switch such as a switch for selecting a switch and a reset switch.

The recording section 8 comprises an EFM encoder 81, a recording signal generation circuit 82, a laser drive control circuit 83, and a laser diode 84. The EFM encoder 81 EFM-modulates the digital information to be recorded and outputs it as a reference digital signal A to a recording signal generation circuit 82. The recording signal generation circuit 82 controls the time of the high level and low level of the reference digital signal A. The width is corrected and output to the laser drive control circuit 83 as a signal E. Ray
When the signal E is at a high level, the drive control circuit 83
A predetermined current is passed through the diode 84 to emit high-intensity laser light capable of forming a pit portion in the recording layer of the optical disk. When the recording signal E is at a low level, the laser
Either a current for emitting laser light of low light intensity capable of forming a non-pit portion in the diode 84 is supplied, or power supply to the laser diode 84 is stopped.

The recording signal generation circuit 82 includes a reference digital signal A corresponding to information to be recorded on the optical disc 1.
And a clock signal CP synchronized therewith, to generate a recording signal E in which the reference digital signal A is corrected based on the correction data DAT, and to use the recording signal E via the laser drive control circuit 83. Then, the laser diode 84 is driven to record information on the optical disk 1. Here, the clock signal CP has a period equal to the reference time width T. As the optical disc 1, for example, a recording layer is formed of a cyanine dye on a substrate on which a tracking group is formed. An optical disk is used in which a gold reflective layer and a protective layer made of an ultraviolet-curable resin are formed on the optical disk. Further, when the reference digital signal A 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 reference digital signal A is at a low level, a low intensity laser beam capable of forming a non-pit portion is irradiated. Irradiate the optical disk or
The setting is made so that the irradiation of the light is stopped to form pits on the optical disc 1.

As shown in FIG. 3, the recording signal generation circuit 82 includes a rear-end pulse generation circuit 100, a plurality of delay circuits 201 to 20.
8, a voltage control circuit 300 and a signal synthesis circuit 400. The rear-end pulse generation circuit 100 detects the high-level and low-level time widths of the reference digital signal A based on the clock signal CP, and the high-level time width is 3 to 6 times the reference time width T. At this time, positive pulse signals P3 to P6 of the reference time width T are output corresponding to each time width, and the low-level time width is 3 to 6 of the reference time width T.
When the time is double, positive pulse signals L3 to L6 of the reference time width T are output corresponding to each time width. Hereinafter, a time width that is n times the reference time width T is referred to as an nT time width.

The rear-end pulse generation circuit 100 includes a shift register 111, NOT circuits 112 to 118, a four-input AND
The shift register 111 has a clock input terminal CLK to which a clock signal CP is input, and a serial data input terminal AB to which a reference digital signal A is input.

The output terminal Qa of the shift register 111 is A
Connected to the first input terminals of the ND circuits 123 to 126, respectively,
To 122 are respectively connected to the first input terminals.
The output terminal Qb of the shift register 111 is connected to an AND circuit 119.
To 122, the second input terminals and the signal combining circuit 40.
0 and AND circuit 113 via a NOT circuit 113.
Each of the circuits 123 to 126 is connected to a second input terminal. The output terminal Qd of the shift register 111 is AND
Connected to the third input terminal of the circuit 119 and NOT
It is connected to the third input terminal of the AND circuit 123 via the circuit 114. The output terminal Qe of the shift register 111 is
The third input terminal of the AND circuit 120 and the AND circuit 123
Of the NOT circuit 115
Are connected to the fourth input terminal of the AND circuit 119 and the third input terminal of the AND circuit 124 via the. The output terminal Qf of the shift register 111 is connected to the third input terminal of the AND circuit 121 and the fourth input terminal of the AND circuit 124, and the fourth input terminal of the AND circuit 120 via the NOT circuit 116. It is connected to the third input terminal of the AND circuit 125. The output terminal Qg of the shift register 111 is
A fourth input terminal of the AND circuit 121 is connected to a third input terminal of the AND circuit 122 and a fourth input terminal of the AND circuit 125 via a NOT circuit 117.
126 is connected to the third input terminal. The output terminal Qh of the shift register 111 is connected to the fourth input terminal of the AND circuit 126 and is connected to the
It is connected to the fourth input terminal of the D circuit 122.

As a result, the high-level time width of the reference digital signal A becomes three times, four times, five times, six times the reference time width T.
At the time of double, pulse signals P3, P4, P5, and P6 are output from AND circuits 119, 120, 121, and 122, respectively. When the low-level time width of the reference digital signal A is 3, 4, 5, or 6 times the reference time width T, the pulse signals L3, L4, L5 from the AND circuits 123, 124, 125, 126 are output.
L6 is output.

As shown in FIG. 4, each of the delay circuits 201 to 208 includes NPN transistors 211, 212, NOT,
Circuits 213 and 214, diodes 215, resistors R1 to R3, and a capacitor C1. A predetermined positive voltage + V1, for example, + 5V is applied to the collector of transistor 211, and the base is connected via resistor R1. AND circuits 119 to 12
6 output terminals. Further, a capacitor C1 is connected between the emitter and the collector of the transistor 211, and the emitter is the collector of the transistor 212, the cathode of the diode 215 and the NO.
It is connected to the input terminal of the T circuit 213. Diode 21
5 is grounded, and the output terminal of NOT circuit 213 is connected to the input terminal of NOT circuit 214. A predetermined negative voltage -V2, for example, -5 V is applied to the emitter of the transistor 212 via the resistor R2, and the base is connected to one end of the resistor R3. Further, predetermined voltages vh3 to vh6 and vl3 to v16 described later are applied to the other end of the resistor R3 by the voltage control circuit 300.

As a result, in the delay circuits 201 to 208, the delay circuit 201 to 208
The on / off state of the transistor 211 is switched by the pulse signals P3 to P6 and L3 to L6 input to the
The rear ends of P6, L3 to L6 are predetermined times th3 to th6, t
Positive pulse signals Pd3 to Pd delayed by l3 to t6
d6, Ld3 to Ld6 are output.

That is, as shown in FIG. 5, the pulse signal P3
When the base voltage Vb of the transistor 211 becomes high level, the transistor 211 is turned on.
Is turned on, the capacitor C1 is discharged,
The input voltage Vin of the NOT circuit 213 becomes the voltage + V1, and N
The output voltage Vout of the OT circuit 214 goes high. When the base voltage Vb of the transistor 211 goes low, the transistor 211 is turned off, and the capacitor C1 is connected to the base voltage of the transistor 212 and the resistor R3.
, A current based on the resistance value flows, and charging of the capacitor C1 is started. Thus, the input voltage V of the NOT circuit 213
in gradually decreases as the charging of the capacitor C1 progresses, and when it becomes lower than the threshold voltage of the NOT circuit 213, NO
The output voltage Vout of the T circuit 214 goes low.

The voltage control circuit 300 is composed of, for example, a register for holding the correction data DAT input from the main control unit 5, a plurality of resistors, analog switches, and the like. Each delay is controlled based on the correction data DAT. The values of the control voltages vh3 to vh6 and vl3 to v16 output to the circuits 201 to 208 are changed.

The signal synthesizing circuit 400 has a three-input OR circuit 40.
1 to 403, 3-input AND circuits 404, 405, 2-input AN
It comprises a D circuit 406, a two-input NOR circuit 407, and two-input OR circuits 408 and 409. The first input terminal of the OR circuit 401 is grounded, and the second and third input terminals are connected to the output terminals of the NOT circuits 214 of the delay circuits 201 and 202, respectively. The first input terminal of the OR circuit 402 is grounded, and each of the second and third input terminals is connected to the delay circuit 203,
It is connected to the output terminal of a NOT circuit 214 at 204.

The first input terminal of the OR circuit 403 is
It is connected to the output terminal Qb of the shift register 111 of the rear-end pulse generation circuit 100 via AND circuits 404 and 405 connected in series. That is, all three input terminals of the AND circuit 404 are connected to the output terminal Qb of the shift register 111,
The output terminal of the AND circuit 404 is connected to three input terminals of the AND circuit 405, and the output terminal of the AND circuit 405 is connected to the first input terminal of the OR circuit 403. OR
The second and third input terminals of the circuit 403 are OR circuits, respectively.
The output terminals of the OR circuit 403 are connected to the first input terminal of the AND circuit 406. A second input terminal of the AND circuit 406 is connected to a NOR circuit 407.
, And two input terminals of a NOR circuit 407 are connected to output terminals of ORD circuits 408 and 409, respectively. The two input terminals of the OR circuit 408 are connected to the output terminals of the NOT circuits 214 of the delay circuits 205 and 206, respectively, and the two input terminals of the OR circuit 409 are connected to the delay circuits 207 and 207.
208 are connected to output terminals of NOT circuits 214, respectively. Further, the output terminal of the AND circuit 406 is connected to a laser diode 84 via a laser drive control circuit 83.

The resistance value of the resistor and the capacitance of the capacitor C1 in each of the above-described delay circuits 201 to 208 are set to appropriate values determined in advance by experiments and the like.

Next, the operation of the present embodiment having the above-described structure will be described with reference to timing charts shown in FIGS. 6 to 9, flow charts shown in FIGS. 10 to 13, and setting data shown in FIG. The description will be made based on the control voltage selection table shown in FIG. In the signal conversion unit 2, the time width detection unit 3 and the main control unit 5, the time width in the reproduced signal based on the pit portion and the non-pit portion formed on the optical disc 1 on a test basis is larger than the time width in the reference digital signal A. Then, based on the detection result, a correction value for the time width of the high level and the low level of the reference digital signal A at the time of recording information on the optical disc 1 is selected.

In this embodiment, the high-level and low-level time widths of the reference digital signal A corresponding to the pit portion and the non-pit portion having a small time width in which the influence of thermal interference is relatively likely to appear are corrected. Actually, the high-level and low-level time widths having a time width 3 to 6 times the reference time width T are corrected.

When selecting a correction value, the light intensity of the laser which is optimal for forming pits on the optical disk 1 is determined in advance, and the reproduction signal from the pits formed on the optical disk 1 is determined based on the optimum light intensity. When recording information with a recording signal generated based on the correction value, the intensity of the laser light is set to the optimum light intensity.
The time width detector 3 and the main controller 5 operate as follows.

A non-pit portion Pb having a predetermined time width, for example, 4
When detecting a shift of the high-level time width in the reproduction signal RF corresponding to the non-pit portion Pb having the T time width, the main control unit 5 switches the analog switch 25 by the switching signal SEL to the comparator 26. The signal RF1 is input and the comparison circuit 36 is connected via the data bus DB.
The data DA11 of the upper limit of the 4T time width is given to the comparator 37, and the data DA12 of the lower limit of the 4T time width is given to the comparator 37.
Are set, and the detection process is started.

As a result, as shown in the timing chart of FIG. 6, the output signal RF of the RF amplifier 22 is AC-coupled and input to the comparator 26. In this case, in the signal RF1, the reflected light intensity from the non-pit portion Pb is set to a positive voltage, and the reflected light intensity from the pit portion Pa is set to a negative voltage.

On the other hand, the count value DA1 of the counter 33 is latched by the latch circuit 34 at the falling edge of the signal RD1 transitioning from the high level to the low level, and the latched data DA2 becomes the next falling edge of the signal RD1. Held until The data DA2 output from the latch circuit 34 is compared with the upper limit value DA11 and the lower limit value DA12 of the 4T time width by the comparing circuits 36 and 37, and the value of the data DA2 is compared with the upper limit value DA11 and the lower limit value DA12. Within the range and the signal R
When D1 is at a high level, the signal WI is at a high level. The data DA2 is latched by the latch circuit 35 at the rise of the signal WI. Therefore, only the data DA2 having a time width within the allowable range of the 4T time width is latched by the latch circuit 3.
5, the data DA3 output from the latch circuit 35 is read by the main controller 5.

When detecting a shift in the low-level time width in the reproduction signal RF corresponding to the pit portion Pa having a predetermined time width, for example, the pit portion Pa having a 5T time width,
The main control unit 5 switches the analog switch 25 by the switching signal SEL, and sends the signal RF2 to the comparator 26.
And the comparison circuit 3 via the data bus DB.
6, the data DA11 of the upper limit of the 5T time width, and the comparator 37 for the data DA11 of the lower limit of the 5T time width.
12 is set and the detection process is started.

As a result, as shown in the timing chart of FIG. 7, the output signal RF of the RF amplifier 22 is AC-coupled, inverted, and input to the comparator 26. In this case, in the signal RF2, the non-pit portion Pb
The reflected light intensity from the pit portion Pa is set to a negative voltage, and the reflected light intensity from the pit portion Pa is set to a positive voltage. The subsequent operation is the same as described above.

The permissible range and the center value for each of the above described 3T to 6T time widths are set in advance to those shown in FIG. For example, the allowable range of the 3T time width is a range of 2.5T or more and smaller than 3.5T, and the center value is 3.0.
When converted to the count value of the counter 33, the data DA11 is 27 in decimal and the data DA112 is 19 in decimal, and these values are set when each time width is detected. .

Next, the processing operation of the main control unit 5 will be described with reference to the flowcharts shown in FIGS. The main control unit 5 constantly monitors whether the data selection switch, the recording switch, or the reset switch is turned on (S).
1, S2, S3), when the data selection switch is turned on, the variable n is set to 3, the variable CN is set to 0, and the variable NH3 is set.
To NH6 and NL3 to NL6 are set to 0 (S
4, S5, S6), the analog switch 25 is switched by the switching signal SEL, and the signal R is sent to the comparator 26.
F1 is input (S7). Thereby, the non-pit portion Pb
Can be detected.

Next, the main controller 5 compares the window data DA11 and DA12 for detecting the nT time width with the comparators 36 and 37.
(S8), it is determined whether the pulse signal WI has been input from the time width detection unit 3 (S8).
9). As a result of this determination, when the pulse signal WI is input, the main control unit 5 outputs the output data DA3 of the latch circuit 35.
Is read (S10), and the value of this data DA3 is stored in a variable NL.
In addition to adding to n (S11), 1 is added to the variable CN (S12), and it is determined whether or not the variable CN exceeds a predetermined constant K, for example, 100 (S13). As a result of this judgment,
If the variable CN does not exceed the constant K, the process shifts to the processing of S9, and if it does, it is determined whether or not the variable n is equal to 6 (S14). If the result of this determination is that the variable n is not equal to 6, 1 is added to the variable n (S15), and at the same time, the variable CN is set to 0 (S16), and the process proceeds to the process of S8. When the variable n is equal to 6, the variable n is set to 3
The variable CN is set to 0 (S17, S18), and the analog switch 25 is switched by the switching signal SEL.
Is switched to input the signal RF2 to the comparator 26 (S19). Thereby, the time width of the reproduction signal corresponding to the pit Pa can be detected.

Next, the main control unit 5 compares the window data DA11 and DA12 for detecting the nT time width with the comparators 36 and 37.
(S20), it is determined whether or not the pulse signal WI is input from the time width detection unit 3 (S2).
1). As a result of this determination, when the pulse signal WI is input, the main control unit 5 outputs the output data DA3 of the latch circuit 35.
Is read (S22), and the value of this data DA3 is
In addition to adding to n (S23), 1 is added to the variable CN (S24), and it is determined whether or not the variable CN exceeds a predetermined constant K (S25). As a result of this determination, if the variable CN does not exceed the constant K, the process shifts to the process of S21, and if it exceeds, it is determined whether or not the variable n is equal to 6 (S2).
6). If the result of this determination is that the variable n is not equal to 6, one is added to the variable n (S28) and the variable CN is added.
Is set to 0 (S29), and the routine goes to the process of S8. When the variable n is equal to 6, the variables NL3 to NL
A value obtained by dividing each of L6, NH3 to NH6 by a constant K is calculated, and a corresponding variable ML3 to ML6, MH3 to M
H6 is set for each (S30). Thereby, the reproduction signal RF corresponding to the non-pit portion Pb and the pit portion Pa
Is calculated for each time width of the high level and the low level.

Thereafter, the main control unit 5 obtains a correction value for each time width of the high level and the low level of the reference digital signal. That is, the main control unit 5 determines whether or not the value of the variable MH3 is equal to or greater than the count value 23 of the counter 33 corresponding to the time width three times the reference time width T (S31), and
Is greater than or equal to 23, it is determined whether the value of the variable ML3 is greater than or equal to 23 (S32). As a result of this determination, when the value of the variable ML3 is 23 or more, the correction values tl3, t for the low-level and high-level time widths having a time width three times the reference time width T of the reference digital signal A are obtained.
h3 is set to 0 (S33), and S42 described later is set.
Move to the processing of.

As a result of the determination in S32, when the value of the variable ML3 is less than 23, the main control unit 5 has a 3T time width in the reference digital signal A by subtracting the value of the variable ML3 from 23. Correction value tl for low level
3, the correction value th3 for the high level having a 3T time width is set to 0 (S34), and the process proceeds to S42 described later.

If the result of the determination in S31 is that the value of the variable MH3 is less than 23, it is determined whether or not the value of the variable ML3 is 23 or more (S35). As a result of this determination, when the value of the variable ML3 is 23 or more, the main control unit 5
The value obtained by subtracting the value of the variable MH3 from the above is set as a correction value th3 for a high-level time width having a 3T time width in the reference digital signal A, and a correction value tl3 for a low level having a 3T time width is set to 0 (S36). Then, the processing shifts to the processing of S42 described later.

As a result of the determination in S35, the variable ML
When the value of 3 is less than 23, the main control unit 5 sets the variable MH
It is determined whether the value of the variable ML3 is equal to the value of the variable ML3 (S3
7) When the value of the variable MH3 is equal to the value of the variable ML3, the value obtained by subtracting the value of the variable MH3 from 23 is respectively applied to the high-level and low-level time widths having a 3T time width in the reference digital signal A. Correction value th3
, Tl3 (S38), and goes to the processing of S42 described later.

As a result of the determination in S37, when the value of the variable MH3 is not equal to the value of the variable ML3, the main controller 5 determines whether or not the value of the variable MH3 is larger than the value of the variable ML3 (S39). ). As a result of this determination, when the value of the variable ML3 is equal to or greater than the value of the variable MH3, the main control unit 5 subtracts the value of the variable MH3 from 23 with a high-level time having a 3T time width in the reference digital signal A. The correction value th3 for the width is set to 0, and the correction value tl3 for the low level having a 3T time width is set to 0 (S40).
The process moves to the process of No. 2. Also, the value of the variable MH3 is
When the value is larger than 3, the value obtained by subtracting the value of the variable ML3 from 23 is set as a correction value tl3 for the low level time width having the 3T time width in the reference digital signal A, and the high level having the 3T time width is used. Correction value th for
3 is set to 0 (S41).

Next, the main controller 5 determines whether or not the value of the variable MH4 is equal to or greater than the count value 31 of the counter 33 corresponding to the 4T time width (S42).
In the above case, it is determined whether or not the value of the variable ML4 is 31 or more (S43). As a result of this determination, when the value of the variable ML4 is 31 or more, the correction values tl4 and th4 for the low-level and high-level time widths having the 4T time width in the reference digital signal A are set to 0 (S44). Then, the processing shifts to the processing of S53 described later.

As a result of the determination in S43, when the value of the variable ML4 is less than 31, the main control unit 5 has a value obtained by subtracting the value of the variable ML4 from 31 and has a 4T time width in the reference digital signal A. Correction value tl for low level
4, and the correction value th4 for the high level having a 4T time width is set to 0 (S45), and the process proceeds to S53 described later.

If the value of the variable MH4 is less than 31 as a result of the determination in S42, it is determined whether or not the value of the variable ML4 is 31 or more (S46). As a result of this determination, when the value of the variable ML4 is 31 or more, the main control unit 5
The value obtained by subtracting the value of the variable MH4 from the above is set as a correction value th4 for a high-level time width having a 4T time width in the reference digital signal A, and a correction value tl4 for a low level having a 4T time width is set to 0 (S47). Then, the processing shifts to the processing of S53 described later.

As a result of the determination in S46, the variable ML
4 is less than 31, the main controller 5 sets the variable MH
It is determined whether the value of the variable ML4 is equal to the value of the variable ML4 (S4
8) When the value of the variable MH4 is equal to the value of the variable ML4, the value obtained by subtracting the value of the variable MH4 from 31 is applied to the high-level and low-level time widths having a 4T time width in the reference digital signal A, respectively. Correction value th4
, Tl4 (S49), and shifts to the processing of S53 described later.

As a result of the determination in S48, when the value of the variable MH4 is not equal to the value of the variable ML4, the main control unit 5 determines whether or not the value of the variable MH4 is larger than the value of the variable ML4 (S50). ). As a result of this determination, when the value of the variable ML4 is equal to or greater than the value of the variable MH4, the main control unit 5 calculates the value obtained by subtracting the value of the variable MH4 from 31 as a high-level time having a 4T time width in the reference digital signal A. The correction value th4 for the width is set to th4, and the correction value tl4 for the low level having a 4T time width is set to 0 (S51).
The process moves to the process of No. 3. Also, the value of the variable MH4 is
When the value is larger than 4, the value obtained by subtracting the value of the variable ML4 from 31 is set as a correction value tl4 for the low level time width having the 4T time width in the reference digital signal A, and the high level having the 4T time width is used. Correction value tl for
4 is set to 0 (S52).

Next, the main controller 5 determines whether or not the value of the variable MH5 is equal to or greater than the count value 39 of the counter 33 corresponding to the 5T time width (S53).
In the above case, it is determined whether or not the value of the variable ML5 is 39 or more (S54). As a result of this judgment, when the value of the variable ML5 is 39 or more, the correction values tl5 and th5 for the low-level and high-level time widths having the 5T time width in the reference digital signal A are set to 0 (S55). Then, the processing shifts to the processing of S64 described later.

As a result of the determination in S54, when the value of the variable ML5 is less than 39, the main controller 5 subtracts the value of the variable ML5 from 39 and has a 5T time width in the reference digital signal A. Correction value tl for low level
5, the correction value th5 for the high level having a 5T time width is set to 0 (S56), and the flow shifts to S64 described later.

If the result of the determination in S53 is that the value of variable MH5 is less than 39, it is determined whether or not the value of variable ML5 is 39 or more (S57). As a result of this determination, when the value of the variable ML5 is 39 or more, the main control unit 5
The value obtained by subtracting the value of the variable MH5 from the above is set as a correction value th5 for a high-level time width having a 5T time width in the reference digital signal A, and a correction value tl5 for a low level having a 5T time width is set to 0 (S58). Then, the processing shifts to the processing of S64 described later.

As a result of the determination in S57, the variable ML
When the value of 5 is less than 39, the main control unit 5 sets the variable MH
It is determined whether the value of the variable 5 is equal to the value of the variable ML5 (S5).
9) When the value of the variable MH5 is equal to the value of the variable ML5, the value obtained by subtracting the value of the variable MH5 from 39 is applied to the high-level and low-level time widths having a 5T time width in the reference digital signal A, respectively. Correction value th5
, Tl5 (S60), and shifts to the processing of S64 described later.

As a result of the determination in S59, when the value of the variable MH5 is not equal to the value of the variable ML5, the main controller 5 determines whether or not the value of the variable MH5 is larger than the value of the variable ML5 (S61). ). As a result of this determination, when the value of the variable ML5 is equal to or greater than the value of the variable MH5, the main controller 5 subtracts the value obtained by subtracting the value of the variable MH5 from 39 into a high-level time having a 5T time width in the reference digital signal A. The correction value th5 for the width is set as the correction value th5, and the correction value tl5 for the low level having the 5T time width is set as 0 (S62).
The processing moves to the processing of step 4. Also, the value of the variable MH5 is
When the value is larger than 5, the value obtained by subtracting the value of the variable ML5 from 39 is set as a correction value tl5 for the low-level time width having the 5T time width in the reference digital signal A, and the high level having the 5T time width is used. Correction value th for
5 is set to 0 (S63).

Next, the main controller 5 determines whether or not the value of the variable MH6 is equal to or greater than the count value 47 of the counter 33 corresponding to the 6T time width (S64).
In the above case, it is determined whether or not the value of the variable ML6 is 47 or more (S65). As a result of this determination, when the value of the variable ML6 is 47 or more, the correction values tl6 and th6 for the low-level and high-level time widths having the 6T time width in the reference digital signal A are set to 0 (S66). Then, the processing shifts to the processing of S75 described later.

As a result of the determination in S65, when the value of the variable ML6 is less than 47, the main control unit 5 has a value obtained by subtracting the value of the variable ML6 from 47 and has a 6T time width in the reference digital signal A. Correction value tl for low level
6, the correction value th6 for the high level having a 6T time width is set to 0 (S67), and the process proceeds to S75 described later.

If the result of S64 is that the value of variable MH6 is less than 47, it is determined whether or not the value of variable ML6 is 47 or more (S68). As a result of this determination, when the value of the variable ML6 is equal to or greater than 47, the main control unit 5
The value obtained by subtracting the value of the variable MH6 from the above is set as a correction value th6 for a high-level time width having a 6T time width in the reference digital signal A, and a correction value tl6 for a low level having a 6T time width is set to 0 (S69). Then, the processing shifts to the processing of S75 described later.

As a result of the determination in S68, the variable ML
6 is less than 47, the main controller 5 sets the variable MH
It is determined whether the value of the variable ML6 is equal to the value of the variable ML6 (S7).
0), when the value of the variable MH6 is equal to the value of the variable ML6, the value obtained by subtracting the value of the variable MH6 from 47 is applied to the high-level and low-level time widths having a 6T time width in the reference digital signal A, respectively. Correction value th6
, Tl6 (S71), and shifts to the processing of S75 described later.

If the result of determination in S70 is that the value of variable MH6 is not equal to the value of variable ML6, main controller 5 determines whether the value of variable MH6 is greater than the value of variable ML6 (S72). ). As a result of this determination, when the value of the variable ML6 is equal to or greater than the value of the variable MH6, the main control unit 5 subtracts the value obtained by subtracting the value of the variable MH6 from 47 into a high-level time having a 6T time width in the reference digital signal A. The correction value th6 for the width and the correction value tl6 for the low level having a 6T time width are set to 0 (S73), and S7 described later.
Then, the process proceeds to step S5. Also, the value of the variable MH6 is
If the value is larger than 6, the value obtained by subtracting the value of the variable ML6 from 47 is used as the correction value tl6 for the low-level time width having the 6T time width in the reference digital signal A.
And a correction value th for a high level having a 6T time width.
6 is set to 0 (S74).

Next, the main controller 5 sets the correction values tl3 to tl3 based on the preset control voltage selection table.
tl6, control voltage values vl3 to v3 corresponding to th3 to th6
l6, vh3 to vh6 are selected and stored in the memory provided in the main controller 5 (S75). In this case, as shown in the control voltage selection table of FIG. 15, each of the control voltage values vl3 to vl6, vh3 to vh6 depends on which of the five selected values corresponds to each of the correction values tl3 to tl6 and th3 to th6. Is selected. That is, when the correction values tl3 to tl6 and th3 to th6 are 0, 1, 2, 3, and 4, respectively, the control voltage values vl3 to v16 and vh3 to vh6 are VA, VB, V
C, VD and VE are selected.

Next, the main control section 5 turns on the selection end lamp on the display section 6 for a predetermined time (S76).
Move to the processing of 1.

When the recording switch is turned on as a result of the determination in S2, the main control unit 5 stores the control voltage values vl3 to vl6 and vh3 to vh6 stored in the memory in the recording signal generation circuit 82. Set in the voltage control circuit 300 (S7
7). Thus, the recording signal E in which the high-level or low-level time width of the reference digital signal A is corrected by the recording signal generation circuit 82 is generated.
Thus, information is recorded on the optical disc 1.

That is, the recording signal generation circuit 82 operates as follows. Each of the pulse signals P3 to P6 and L3 to L6 output from the rear end pulse generation circuit 100 is output from the output terminal Qb of the shift register 111 as shown in FIGS.
, Ie, the reference digital signal A
It corresponds to the signal B delayed by the clock pulse CP, and the trailing ends of the pulse signals P3 to P6 are at the trailing end of a high level having a time width 3 to 6 times the reference time width T of the reference digital signal A. Coincide with each other and the pulse signals L3 to L6
Is output so as to coincide with the rear end of a low level having a time width 3 to 6 times the reference time width T of the reference digital signal A. Further, these pulse signals P3 to P3
6, and the respective time widths of L3 to L6 are equal to the reference time width T.

As described above, the pulse signals P3 to P6 and L3 to L6 output from the rear end pulse generation circuit 100 have their rear ends at the above-described times th3 to th6 and th3 to th6, respectively, by the corresponding delay circuits 201 to 208. The output is delayed by tl3 to tl6.

After that, the signal combining circuit 400 combines the pulse signals Pd3 to Pd6 and Ld3 to Ld6 with the signal B, and inputs the combined signal as the signal E to the laser drive control circuit 2. That is, in the signal synthesis circuit 400, the pulse signal Pd
OR signals 401 to 403 are ORed with the signal B by the OR circuits 401 to 403 to obtain a signal D. Thereby, in the signal D,
The high-level time width having a time width 3 to 6 times the reference time width T is lengthened by the times th3 to th6, respectively, and the low-level time width following them is shortened accordingly.

Further, the signal D is ANDed with a signal obtained by further inverting a signal obtained by logically ORing the pulse signals Ld3 to Ld6 by the AND circuit 406, and is output as a recording signal E. As a result, in the recording signal E, the rear end of the low level having a time width of 3 to 6 times the reference time width T is extended by the time tl3 to tl6, respectively, and the subsequent high level time width is shortened accordingly. Be killed. This recording signal E
Is input to the laser drive control circuit 83.

The laser drive control circuit 83 supplies a predetermined current to the laser diode 84 when the recording signal E is at a high level, and forms a high light intensity laser capable of forming a pit portion on the recording layer of the optical disk. Emits light, and the recording signal E is low.
When the level is at the level, a current for emitting a laser beam of low light intensity capable of forming a non-pit portion in the laser diode 84 is supplied, or the supply of the laser diode 84 is stopped.

If the result of determination in S3 is that the reset switch has been turned on, the main control unit 5 deletes the correction value stored in the memory (S78) and proceeds to the processing in S1.

Therefore, according to the present embodiment, the main control unit 5
Is a reproduction signal RF corresponding to the pit portion Pa and the non-pit portion Pb having a time width of 3T to 6T in which the influence of thermal interference appears remarkably.
Since the set value of the control voltage to the voltage control circuit 300 is changed based on the low-level and high-level time widths of the reference digital signal A, the high-level or low-level time width of the reference digital signal A is individually changed. The effect of thermal interference between pits during information recording can be reduced, and pits consisting of pits and non-pits having a length corresponding to the time width of the reference digital signal A can be formed. This allows
Since the recording / reproducing characteristics can be improved and the intensity of the laser beam at the time of recording can be set low, double speed recording is also possible. Further, the optical pickup 21, the laser
Even if the diode 84, the wavelength of the laser beam, or the type of the optical disc 1 changes, it is possible to cope with the change immediately, and it is possible to always maintain high recording / reproducing characteristics.

In this embodiment, the reference digital signal A
Is a recording signal E in which the time width of the high level and the low level whose time width is 3 to 6 times the reference time width T is changed.
Is generated, but the present invention is not limited to this, and the correction target may be changed as necessary.

Further, in the present embodiment, the correction is performed by increasing the time width of the high level or the low level in the reference digital signal. However, the correction may be performed by reducing the time width, After the time width of the level is uniformly reduced, each time width may be increased and corrected.

The circuit configuration of this embodiment is an example,
It is needless to say that the present invention is not limited to this.

[0084]

As described above, according to the first aspect of the present invention,
According to the method, the time width of the first signal level of the reference digital signal is corrected based on each time width detected from the reproduction signals from the pit portion and the non-pit portion formed on the optical information recording medium on which information is to be recorded. A pit is formed by irradiating a laser beam to the optical information recording medium with the generated recording signal and forming a pit by using the recording signal. Therefore, it is possible to reduce the influence of thermal interference between pit portions during information recording. As a result, a pit having a length corresponding to the time width of the reference digital signal and including a pit portion and a non-pit portion can be formed. As a result, the recording / reproducing characteristics can be improved, while the remaining
In order to be able to record efficiently without using significant thermal energy,
Since the intensity of the laser beam during recording can be set lower than in the past, when performing high-speed recording, the conventional laser
It is possible to record without using high-strength materials,
The recording power can be moderate and thermal interference
Since it is difficult to produce, double-speed recording is also facilitated. Further, even if the wavelength of the optical pickup or the laser beam or the type of the optical information recording medium is changed, it is possible to cope with the change immediately, and it is possible to always maintain high recording / reproducing characteristics.

According to the second aspect, the correction time width selecting means is based on each time width detected from the reproduction signals from the pit portion and the non-pit portion formed on the optical information recording medium on which information is to be recorded. An increase / decrease value of the time width of the signal level of the reference digital signal is obtained, and the recording signal refining means uses the increase / decrease value to determine the first value of the reference digital signal.
And a recording signal in which the time width of the second signal level is corrected is generated, and the recording signal is used to irradiate the optical information recording medium with laser light to form pits. Can reduce the effects of thermal interference,
A pit including a pit portion and a non-pit portion having a length corresponding to the time width of the reference digital signal can be formed. Thereby, the recording / reproducing characteristics can be improved, and on the other hand, efficiently without using extra heat energy.
Since recording can be performed , the intensity of laser light during recording can be set lower than in the past, so that high-speed recording can be performed.
Can record without using as high intensity as a conventional laser.
It should be possible and the recording power should be moderate
And double-speed recording
Also becomes easier. Further, even when the optical pickup, the wavelength of the laser beam, the optical information recording medium, or the like changes, it is possible to cope with the change immediately, and a very excellent effect that the high recording and reproducing characteristics can be always maintained. To play.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a relationship between a reference digital signal and pits in a conventional example.

FIG. 3 is a configuration diagram showing details of a recording signal generation circuit in one embodiment of the present invention.

FIG. 4 is a configuration diagram of a delay circuit in one embodiment.

FIG. 5 is a timing chart of a delay circuit in one embodiment.
G

FIG. 6 is a timing chart for selecting a correction value in one embodiment.

FIG. 7 is a timing chart for selecting a correction value in one embodiment.

FIG. 8 is a timing chart at the time of recording information in one embodiment.

FIG. 9 is a timing chart at the time of recording information in one embodiment.

FIG. 10 is a control flowchart in one embodiment.

FIG. 11 is a control flowchart in one embodiment.

FIG. 12 is a control flowchart in one embodiment.

FIG. 13 is a control flowchart in one embodiment.

FIG. 14 is a diagram showing a setting data table in one embodiment;

FIG. 15 is a diagram showing a control voltage selection table in one embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Signal conversion part, 21 ... Optical pickup, 22 ... RF amplifier, 23 ... AC coupling, 24
... Inverter, 25 ... Analog switch, 26 ... Compare
3, a time width detector, 31 a flip-flop, 32
.. NOT circuit, 33 counter, 34, 35 latch circuit, 36, 37 comparison circuit, 38 AND circuit, 5 main control unit, 6 display unit, 7 switch unit, 8 recording unit, 8
1: EFM encoder, 82: recording signal generation circuit, 83
... Laser drive control circuit, 84 ... Laser diode, 100
… Tail pulse generation circuit, 201 to 208… Delay circuit, 300…
Voltage control circuit, 400 ... signal synthesis circuit.

Claims (2)

(57) [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 time widths forming an arithmetic series that is an integral multiple of a predetermined reference time width. In an optical information recording method for forming a pit by irradiating a laser beam of a predetermined intensity to an optical information recording medium based on a reference digital signal having A plurality of different test areas on the optical information recording medium based on
A step of reproducing the information after trial recording information using a laser beam intensity, repeated multiple times, Le - with determining the proper light intensity The, Le of the proper light intensity - recording the laser light Detecting the reflected light intensity of the reproduction laser light from the pits formed experimentally using the light, reproducing the information recorded on the optical information recording medium as a digital signal based on the reflected light intensity, High or low level of the reproduced digital signal
While detecting the time width of the level, from the time width,
After extracting a time width included in the reference time width around a comparison time width of a time width equal to or less than a predetermined length, the time width is compared with the comparison time width, and based on the comparison result, At least a high level or low level of the reproduced digital signal is set so that these time widths are equal.
An increase / decrease value of the time width of the signal level of the reference digital signal corresponding to the level and having the time width to be compared is determined. An optical information recording method, comprising: generating a recording signal having a corrected time width; and irradiating the optical information recording medium with laser light using the recording signal to form a pit. 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 indicating a laser light irradiation stop period. The first and second signal levels are converted to a reference digital signal having a time width that is an integral multiple of a predetermined reference time width. An optical information recording device for irradiating the optical information recording medium with laser light having a predetermined intensity to form pits, wherein light intensity detecting means for detecting the intensity of light reflected from the optical information recording medium; A signal reproducing means for reproducing information recorded on the optical information recording medium as a digital signal based on a detection result of the light intensity detecting means; a high level or a low level of the digital signal reproduced by the signal reproducing means; of A time width detecting means for detecting a time width; and from the time widths detected by the time width detecting means, the time widths are included in the reference time width around a comparison target time width of a time width equal to or less than a predetermined length. Time width extracting means for extracting a time width; time width comparing means for comparing the time width extracted by the time width extracting means with the comparison target time width; and a digital signal reproduced by the signal reproducing means.
The reference data is set so that the interval becomes an integral multiple of the reference time width.
A correction value selection table in which a correction value obtained by an experiment in advance for correcting the time width of the digital signal is set, and based on a comparison result of the correction value selection table and the time width comparison means, When extracted by the time width extraction means
At least the high level or low level of the reproduced digital signal is set so that the interval width becomes equal to the comparison target time width.
Correction time width selecting means for determining the increase / decrease value of the time width of the signal level of the reference digital signal having the comparison target time width, and using the increase / decrease value selected by the correction time width selection means. Recording signal generating means for generating a recording signal in which the time width of each signal level in the reference digital signal is corrected; and laser driving control means for controlling laser driving based on the recording signal. An optical information recording apparatus, characterized in that: