JP2998912B2 - Optical disk recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device,
In particular, the present invention relates to an apparatus for recording an information signal on an optical disk by a mark length recording method.

2. Description of the Related Art An optical disk device has a large capacity and is capable of exchanging media. For example, an optical disk device is used as a filing system for storing image data, an external storage device for a computer capable of recording and reproducing code data, and Recently, a large number of copies can be made from a master disk, such as a compact disk, and its application field is rapidly expanding as a software supply medium and further as a backup device.

[0003] In such an optical disk apparatus, an optical disk medium to be recorded and reproduced is a read-only medium typified by a CD-ROM and a once-recordable additional recording mainly used in a filing apparatus for handling image information. Mold media,
Currently, three types of rewritable media capable of handling code information and recording / erasing many times are currently being marketed.

Among these, the third rewritable medium is a 5-inch magneto-optical disk whose medium format is determined by the International Organization for Standardization (ISO). Following the 5 inch media format, a smaller 3.5 inch media format is also available.
Determined by SO, several types of 3.5-inch optical disks have already been shipped.

For widespread use of 5-inch and 3.5-inch optical disks in the future, it is essential to further reduce the cost and to further improve the performance and increase the capacity. There is a need for a recording method and a recording device for accurately recording desired information in a system.

[0006]

2. Description of the Related Art Conventionally, as a recording method of an optical disk, a pit position recording method (also called an inter-mark recording method) performed on a rewritable optical disk,
A pit edge recording method (also called a mark length recording method) used in compact discs is known. The inter-mark recording method and the mark length recording method will be described with reference to FIG.

Now, as a recording data sequence, FIG.
When "0100100000001000" is entered as shown in, the mark interval recording method as shown hatched in FIG. (B), recorded pits on disk position corresponding to the data "1" (domain) P _1, record the P ₂ and P _3, the data is "0" in the disk on a position corresponding to not record the recording pits. That is, the inter-mark recording method is a recording method in which the presence or absence of a recording pit corresponds to recording data "1" and "0". At the time of reproducing the optical disc recorded by the inter-mark recording method, data can be detected by detecting the peak point of the reproduced waveform shown in FIG.

On the other hand, in the mark length recording method, recording is performed by inverting the recording light intensity for each bit position of the value "1" of the input data series. As shown, this is a recording method in which the edges of recording pits (domains) P ₁₀ and P ₁₁ are located at positions on the disk corresponding to data “1”.

At the time of reproducing an optical disk recorded by this mark length recording method, data can be detected by binarizing a reproduced waveform shown in FIG. 1E at a reference point (slice level). As can be seen from FIG. 10, the mark length recording has a higher recording density than the inter-mark recording, and if the shortest mark length is the same, the mark length recording achieves twice the recording density as the inter-mark recording. be able to.

Therefore, in order to improve the recording density of the optical disc, it can be said that it is suitable to record the recording data value "1" by the mark length recording method corresponding to the edge of the recording pit. However, in this mark length recording method, reproduction discrimination of the edge recording position of the recording pit is important, but the recording process of the optical disk is a so-called heat mode recording using a laser beam irradiated from a semiconductor laser as a heat source. For this reason, it is necessary to remove a thermal shift and a pattern shift that occur during the recording process.

That is, the recording data sequence shown in FIG. 11A is converted into a recording pulse of a mark length recording system as shown in FIG. When recording is performed by raising the temperature of the irradiation position and causing magnetization reversal, recording is performed later of two adjacent recording pits P ₂₁ and P ₂₂ as shown in FIG. the front edge of the pit P ₂₂ is, by the influence of heat preceding pit P _21, only ΔPt than the recording position of the original leading edge in the direction of the preceding pit P ₂₁ in advance will be recorded.

This is the above-mentioned thermal shift, which is the interval between the preceding pit and the pit to be recorded, in other words, the pulse interval of the recording pulse (FIG. 11B).
(Low-level period) becomes shorter, the thermal shift amount ΔPt becomes larger as shown in FIG.

A recording data sequence shown in FIG.
Is a recording pulse of a mark length recording method as shown in FIG.
To increase the light intensity during the high-level period of the recording pulse.
In the same heat mode recording as above,
As shown in (C), two adjacent recording pits P₃₁And P
₃₂Is formed on the optical disk, the pit P
₃₁And P₃₂Because the medium temperature gradually rises when recording
Pit P₃₁And P₃₂The recording position of the trailing edge is the original recording
The position is shifted backward by ΔPc, ΔPc + ΔPp from the position.
I will.

This is the pattern shift described above. The longer the length of the recording pit, in other words, the longer the pulse width of the recording pulse (the high-level period in FIG.
As shown in FIG. 2D, the pattern shift amount ΔPp increases. Incidentally, Delta] Pc is the difference from the original pit length of the recording pit P ₃₁ when the recording pulse of the shortest pulse width after the longest pulse intervals, called steady shift.

In order to realize the mark length recording method, it is important to remove the thermal shift ΔPt and the pattern shift ΔPp from the thermal shift ΔPt, the pattern shift ΔPp, and the stationary shift ΔPc on the recording side. This is because the steady-state shift ΔPc is a component that changes depending on the medium sensitivity and the environmental temperature, and is mainly composed of low-frequency components. Therefore, it can be compensated by the signal processing system.
This is because the two shifts ΔPt and ΔPp are expected to have the same frequency components as the recording frequency of the signal, and it is difficult to compensate on the reproduction side.

Therefore, conventionally, an optical disk recording / reproducing device (JP-A-63-53722) or an optical information recording / reproducing device (JP-A-63-63722) which detects a recording data pattern and controls a pulse width according to the pattern. 281229) has been proposed. Among these, in the former conventional device, the closest pattern is detected using input data and a clock, and the selector is driven by the detected closest pattern signal to drive one of the output taps of the plurality of output taps of the delay element. A signal is selected, and a logical product of the signal and a non-delayed recording pulse is taken to shorten the pulse width of the recording pulse by the amount of delay. Also,
In the latter conventional device, a pulse having the shortest time length is detected from a recording pulse train, and this is given a correction amount different from that of other pulses.

[0017]

However, in the above-mentioned conventional device, the control amount at the rising time of the recording pulse is the same as the control amount at the falling time of the recording pulse. It is impossible to correct the thermal shift ΔPt or the pattern shift ΔPp.
Further, since the latter conventional device performs the same recording pulse correction as the former conventional device, it is impossible to completely correct the edge shift for the same reason.

The present invention has been made in view of the above points,
It is an object of the present invention to provide an optical disk recording apparatus that solves the above-mentioned problem by individually controlling the rising point and the falling point of a recording pulse.

[0019]

FIG. 1 is a block diagram showing the principle of the present invention. The present invention detects the change in the amount of reflected light from the recording surface or the rotation of the reflective polarization surface, and modulates the light intensity with a recording pulse by the mark length recording method on an optical disk in which recorded information is reproduced. An optical disk recording apparatus that records and forms information as intermittent rows of recording pits by irradiating the formed light beam with a pulse width measuring unit 11,
The configuration includes a pulse interval measurement unit 12, a first memory 13, a second memory 14, a first delay circuit 15, a second delay circuit 16, and a flip-flop 17.

A pulse width measuring unit 11 measures a pulse width of the recording pulse corresponding to a length of the recording pit. The pulse interval measuring unit 12 measures a pulse interval of the recording pulse. The first memory 13 receives the output of the pulse width measuring unit 11 as an address, and outputs data of an edge shift amount to be corrected corresponding to the measured pulse width. The second memory 14 receives the output of the pulse interval measuring unit 12 as an address, and outputs data of an edge shift amount to be corrected corresponding to the measured pulse interval.

The first delay circuit 15 includes a first memory 1
Based on the output data of No. 3, a first delay pulse with a smaller delay amount is output as the measurement pulse width increases. Second
The delay circuit 16 outputs a second delay pulse having a larger delay amount as the measurement pulse interval becomes smaller, based on the output data of the second memory 14. Flip-flop 17
The first and second delay pulses are input to a reset terminal and a set terminal, respectively, and a correction recording pulse for modulating the light intensity of the light beam is output from an output terminal.

[0022]

According to the present invention, in realizing a mark length recording method effective for improving the recording density of an optical disk, the flip-flop 17 is reset with a first delay pulse having a smaller delay amount as the pulse width of the recording pulse increases. Therefore, the falling position (trailing edge) of the output correction recording pulse of the flip-flop 17 can be made earlier as compared with the original recording pulse as the pulse width of the recording pulse increases.

Further, since the flip-flop 17 is set with the second delay pulse having a larger delay amount as the pulse interval of the recording pulse becomes smaller, the rising position (leading edge) of the output correction recording pulse of the flip-flop 17 is set. The shorter the pulse interval of the recording pulse, the slower it can be than that of the original recording pulse. Further, in the present invention, the control of the rising position and the falling position of the correction recording pulse can be controlled independently of each other.

[0024]

FIG. 2 is a block diagram showing one embodiment of the present invention. The present embodiment is characterized in that a recording compensation circuit 23 having a configuration described later is provided in a recording system of a magneto-optical disk recording / reproducing apparatus. In FIG. 2, components other than the recording compensation circuit 23 have a known configuration. In the figure, a controller 21 is a control device for controlling the operation of the entire magneto-optical disk recording / reproducing apparatus, and is connected to a higher-level device (usually a computer) via a predetermined interface.
And are connected respectively. The predetermined interface is, for example, SCSI (Small Computer System Interface).
e).

The formatter 22 inputs the input data which is an NRZ (non-return-to-zero) signal during recording,
The encoder 22a encodes the data into a code (for example, a (2,7) run length limiting code) suitable for recording by the mark length recording method, supplies the encoded data (recording pulse) to the recording compensation circuit 23, and reproduces the data. At times, the reproduction signal from the data discriminator 29 is demodulated by the demodulator 22b into NRZ signal data.

At the time of recording, the recording compensating circuit 23 measures the pulse width and pulse interval of the input coded data (recording pulse) by a predetermined circuit configuration as described later, and determines the rising position of the pulse based on the measurement result. A correction recording pulse whose fall position is corrected is generated and supplied to the LD drive system 24.

The LD drive system 24 has a configuration in which the above-mentioned correction recording pulse is inputted to a driving circuit of a semiconductor laser (LD). For example, during the high level period of the above-mentioned correction recording pulse, the magneto-optical disk is sufficiently heated and magnetized. A recording light beam modulated to a large light intensity that causes inversion and modulated to a small light intensity that does not cause the magnetization reversal during the low level period of the correction recording pulse is generated and supplied to the optical head 25. I do. Although not shown, the LD drive system 24 generates a reproduction light beam having a constant light intensity that does not cause magnetization reversal from the LD during reproduction.

On the other hand, at the time of reproduction, the ID signal which is the sum component of the reflected light from the magneto-optical disk and the magneto-optical signal which is the difference signal are input to the switch 26 by the optical head 25,
Each signal is selected in the D area and the user data area. The output signal of the switching unit 16 is input to a reproducing circuit 27, where the signal level change caused by the characteristics of the medium, the tracking characteristics of the optical head 25, etc. is rescued.
It is pulsed through a C (Auto Gain Control), a filter for removing noise in a high frequency range, and an equalizer for compensating for resolution.
From the pulsed data, a clock component is extracted by a phase locked loop (PLL) circuit 28, a true data pulse is created by a data discriminator 29, and the demodulator 2
Reproduction data is detected via 2b. In the reproduced data, the formatter 22 determines a track number, a sector number, and recording information.

Next, the configuration of the optical head 25 is shown in FIG.
It is explained together with. The optical head 25 itself has a well-known configuration, and as shown with the magneto-optical disk 50 in FIG. 3, a light beam emitted from the semiconductor laser 31 driven by the LD drive system 24 is applied to the collimating lens 3.
After being converted into parallel light by 2, the light passes through the beam splitter 33, is reflected by the reflection mirror 34, and is incident on the objective lens 35.

The objective lens 35 focuses the incident light beam,
A light spot is formed on the medium surface of the magneto-optical disk 50 so as to be in focus. The objective lens 35 itself includes an amplifier 46 described later.
The position of the output control signal is controlled by a signal obtained by signal processing of the output control signal, so that the minute spot narrowed down to near the diffraction limit following the eccentricity and surface vibration of the magneto-optical disk 50 can be accurately tracked. Irradiation. In this figure, the moving mechanism of the optical head is not shown.

At the time of recording and erasing, by increasing the irradiation laser power, the medium temperature rises above the Curie temperature only in the portion where the laser spot is applied, and is applied to the magneto-optical disk 50 from the bias coil 36 shown in FIG. The medium magnetization is aligned in the direction in which the magnetic field is applied by the applied external magnetic field.

At the time of reproduction, a signal on the recording medium is detected by using the reflected light from the magneto-optical disk 50. The reflected light from the magneto-optical disk 50 condensed by the objective lens 35 travels backward in the same optical path as at the time of incidence, is reflected by the beam splitter 33 that has passed at the time of incidence, and is separated from the incident optical path. The reflected laser light split by the beam splitter 33 is split into two by a beam splitter 37 into transmitted light and reflected light. The reflected light passes through a lens 38, a photodetector 39, and an amplifier 46, and an error signal for focus and track control necessary for the objective lens 35 to accurately follow the track is detected.

On the other hand, the light transmitted through the beam splitter 37 is split by the polarization beam splitter 41 after passing through the wave plate 40, and is split through the condenser lenses 42 and 44, respectively.
3, 45. The output electric signals of the photodetectors 43 and 45 are input to a differential amplifier 47 and a sum amplifier 48, respectively. The magneto-optical signal (MO signal) is detected by the differential amplifier 47, and the ID signal is detected by the sum amplifier 48. You. I
The D signal is a signal recorded in advance as unevenness on a track, and includes a traffic number and a sector number. This signal is a change in the amount of light due to light being diffracted by irregularities on the recording medium. On the other hand, detection of a magneto-optical signal utilizes the magnetic Kerr effect in which the polarization state of light changes depending on the direction of magnetization.

Next, the medium configuration of the magneto-optical disk 50 will be described with reference to FIG. As shown in FIG. 4, the magneto-optical disk 50 has a recording layer 53 formed on a substrate 52, and a pre-groove 54, which is a track guide groove for a light spot to follow a predetermined track, covers the entire surface. It is formed in advance with a pitch of 1.6 μm. The depth of the pre-groove 54 is set to a depth of about １ ／ of the wavelength λ of the light beam in order to maximize the sensitivity of the track error signal.

The land 5 is located between the adjacent pregrooves 54.
5 are formed. The land portion 55 is irradiated with a minute spot collected by the objective lens. And
An ID signal such as a track number or a sector number is formed at a predetermined position of the land portion 55 in advance in a disk manufacturing stage in an uneven shape as shown by 56 in FIG. The depth of the ID signal recording pit 56 is λ to prevent the track error signal generated by the pregroove 54 from being affected.
/ 4 or a value in the vicinity thereof.

The recording information (user data) is indicated by 57 in the recording layer 53 of the land portion 55 following the ID signal recording pits 56, not as unevenness, but in the direction of magnetization of the magnetic film by the mark length recording method described above. As described above. The light beam enters from the back surface of the substrate 52 and is focused on the recording layer 53 at the same time during recording and reproduction.

Next, the principle of detecting a magneto-optical signal will be described. As shown in FIG. 5B, the polarization plane of the reflected light that is incident on and reflected by the magneto-optical disk 50 is, for example, in the plus direction in the reflected light A from the portion whose magnetization direction is downward as shown in FIG. In the reflected light B from the part whose direction is upward, each of them rotates θ _{k in the} minus direction, for example. The above θ
_k is called a car rotation angle and is a very small value of about 1 °.

The reflected lights A and B have an S-polarized light component and a P-polarized light component, respectively, and can be illustrated by different vectors as shown in FIG. Therefore, in the reproducing system, as shown in FIG. 3, the polarization plane of the reflected light is separated into a P-polarization component parallel to the incident plane of the polarization beam splitter 41 and an S-polarization component perpendicular thereto. Polarization beam splitter 41 transmits P-polarized light component, so reflects the S-polarized component, Ca - rotation angle theta _k
Can be detected.

The detected P-polarized light component is 45
Since the degree offset is added, the following equation is obtained from FIG.

P = K {cos ² (45−θ _k ) −cos ² (45 + θ _k )} = K · sin (2θ _k ) (1) Next, the recording compensation circuit 23, which is a main part of this embodiment, The configuration and operation will be described. The recording compensation circuit 23 has the principle configuration shown in FIG.
FIG. 6 is a circuit diagram of an embodiment of the first memory 13 and a portion of the first memory 13.
Shown in In the figure, a pulse width measuring unit 11 includes a counter 61,
It comprises inverters 62 to 64, a latch 65, and D-type flip-flops 66 to 69. Further, the first memory 13 is configured by the memory 70.

The output terminals Q _{A to} Q _D of the counter 61 are connected to the data input terminals D _{1 to} D ₄ of the latch 65.
The output terminals Q _{A to} Q _{D of} the latch 65 are connected to the address input terminals A _{0 to} A ₃ of the memory 70. The memory 70 stores in advance a table of an edge shift amount to be corrected for each of the plurality of pulse widths.

Next, the operation of this embodiment will be described with reference to the time chart of FIG. The recording pulse as shown in FIG. 7A, which is coded in a format most suitable for the mark length recording method described above, is inverted by an inverter 62, and then an enable terminal of a counter 61 and a D-type flip-flop 6.
6 is input to the clear terminal of the counter 61 through the inverter 63, and is further input to the clock terminal of the latch 65 through the inverter 64.

In the counter 61, the write clock shown in FIG. 7 (B) is applied to the clock terminal, and the enable terminal is in the low level period, that is, the high level period of the recording pulse (pulse width period), And outputs a count value as shown in FIG. 7 (C). Also,
The counter 61 is cleared when the write clock rises while a low level is input to the clear terminal. However, since the write clock and the recording pulse are synchronized with each other, FIGS. Is cleared at the falling point of the recording pulse as shown in FIG.

The output count value of the counter 61 is latched by the latch 65 at the falling point of the recording pulse.
The output of the latch 65 is as shown in FIG. The count value of the counter 61 held by the latch 65 is a measured value of the pulse width of the recording pulse, and is input to an address terminal of the memory 70 and is a digital data indicating a delay amount corresponding to the measured value of the pulse width. Is read out and output as shown in FIG. The digital data is set so that the larger the measured value of the pulse width of the recording pulse, the smaller the delay amount.
Is input to In this case, the width of the data bus through which the digital data is transmitted is determined by the required delay resolution, range width, code conversion method, and recording density.

The D-type flip-flops 66 to 69 constitute a shift register, and output a pulse obtained by delaying a recording pulse by a period that is an integral multiple of a write clock. The delay recording pulse extracted from this shift register is shown in, for example, FIG. This shift register stores the access time of the memory 70 and the subsequent delay circuits 14,1.
5 is provided to secure the setup time.

As shown in FIG. 7 (G), when the pulse width measurement value of the recording pulse is "3", a delayed recording pulse (see FIG. fall time T _a delayed reset pulse from the time of the (F)) is generated, the pulse width measurement value is "7" time _{T b (T a> T b} ) delayed reset pulse is generated when the You.

The memory 70 is connected to the control bus 71 of the controller 21 so that the storage data can be changed by the controller 21 according to the recording track number, the medium sensitivity, and the environmental temperature. In this case, the more the recording track number indicates the inner circumferential position of the magneto-optical disk 50, the more the angular velocity type of the magneto-optical disk 5
Since the recording wavelength of 0 becomes shorter even in the same bit period, the recording wavelength becomes susceptible to the effect of thermal shift. Therefore, the data in the memory 70 is changed to correct this. Similarly,
The higher the medium sensitivity and the higher the ambient temperature, the more susceptible to a thermal shift and a pattern shift.

The pulse interval measuring section 12 and the second memory 14 can be constituted by a circuit configuration in which the inverter 62 is omitted in FIG. However, in this case, the memory 70 stores digital data indicating a larger delay amount as the measured value of the pulse interval of the recording pulse becomes smaller.

Next, the first and second delay circuits 15
, And the configuration and operation of 16 will be described. FIG. 8 (A)
Shows the configuration of the first embodiment of the delay circuits 15 and 16 described above. That is, the delay circuits 15 and 16 are each constituted by a programmable delay 81 as shown in FIG. The programmable delay 81 receives the delayed recording pulse shown in FIG. 7F from the shift register composed of the D-type flip-flops 66 to 69 shown in FIG. Is input to the data input terminal.

The programmable delay 81 is shown in FIG.
In synchronism with the rising edge of the input delay recording pulse of the trigger terminal shown in FIG. 5, an internal ramp generator generates a ramp wave having a constant gradient as shown in FIG. Digital data of internal D
/ Obtained through A converter in Fig. (B) and a reference voltage shown by a dashed line 82 and level comparison, thereby output from the output terminal Q _D generates a reset pulse, as shown in FIG. (D).

A programmable delay 81 having such a configuration is commercially available (for example, AD9500 of Analog Devices, Inc., Data Book 90/91, Analog Devices, Inc., pages 8-87 to 8-97), and a data input terminal. The level of the reference voltage 82 changes in accordance with the value of the digital data to change the delay time of the output reset pulse with respect to the input delay recording pulse.

FIG. 9 is a block diagram showing a second embodiment of the delay circuit used as the delay circuits 15 and 16. This embodiment includes a delay line 91 having a multi-tap structure and a multiplexer 92. The delay line 91 having a multi-tap structure has a gate element or a passive element, and n · Δ
τ (where Δτ is a unit delay time, n = 1, 2,...,
It has m taps for extracting the delayed output of m).

The multiplexer 92 selects one of the m taps according to the value of the digital data extracted from the memory 70, and outputs the tap output to a terminal 93 as a reset pulse. 8 and 9 use the output delay pulse as the reset pulse, but in the case of the second delay circuit 16, the output delay pulse is used as the set pulse.

The output reset pulse of the first delay circuit 15 and the output set pulse of the second delay circuit 16 are applied to the reset terminal and the set terminal of the flip-flop 17 shown in FIG. 1, respectively. The set pulse is stored in the second memory 14
Is a delay pulse to which a larger delay amount is added as the pulse interval of the recording pulse becomes smaller, based on the output data of
Therefore, when the recording pulse is a pulse as shown in FIG. 7A, the set pulse is as shown in FIG. 7H, and when the pulse interval of the counter value is about "3" is short, as shown in FIG.
Rises at relatively large time L _a delayed position from the rising position of the delayed recording pulse shown in the counter value rises at a relatively small becomes time L _b delayed position when a long pulse interval of about "6".

Therefore, as shown in FIG. 7 (I), a correction recording pulse which rises when a reset pulse is input and rises when a set pulse is input is taken out from the flip-flop 17, and the LD drive system 2 shown in FIG.
4 is output.

When the pulse width of the correction recording pulse is long, the falling position is advanced so that the pulse width becomes short, so that the above-described pattern shift can be substantially eliminated. In addition, when the pulse interval of the correction recording pulse is small, the rising position is delayed so that the pulse interval becomes wide, so that the above-described thermal shift can be substantially eliminated. The environmental temperature in the present embodiment, since the above-mentioned delay time further medium sensitivity depending on the recording track number _{T a, T b, L a} , the controller 21 L _b is variably set, and more accurate In addition, the pattern shift and the thermal shift including the stationary shift can be eliminated.

It should be noted that the present invention is not limited to the above-described embodiment, and it is only necessary to have at least a recording system. Therefore, the present invention does not need to have a reproducing system. The present invention can also be applied to a recording system for a write-once optical disc, and further to a stamper making machine (such as a pre-groove writer) for making a master substrate of the optical disc.

[0058]

As described above, according to the present invention, the rising position and the falling position are separately controlled in accordance with the pulse width and the pulse interval of the recording pulse coded based on the mark length recording method. Since the correction recording pulse can be generated, the pattern shift and the thermal shift can be substantially eliminated, and the data stored in the memory can be externally changed.
It has features such as the ability to remove pattern shifts and thermal shifts with high accuracy according to the medium sensitivity of the optical disk and the recording position of the optical disk.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a configuration diagram of one embodiment of the present invention.

FIG. 3 is a configuration diagram of an example of an optical head in FIG. 2;

FIG. 4 is a diagram showing a medium configuration of a magneto-optical disk.

FIG. 5 is a diagram illustrating the principle of detecting a magneto-optical signal.

FIG. 6 is a circuit diagram of an embodiment of a main part of the present invention.

FIG. 7 is a time chart for explaining the operation of FIGS. 1 and 6;

FIG. 8 is an explanatory diagram of a first embodiment of the delay circuit according to the present invention.

FIG. 9 is a configuration diagram of a second embodiment of the delay circuit according to the present invention.

FIG. 10 is an explanatory diagram of an inter-mark recording method and a mark length recording method.

FIG. 11 is an explanatory diagram of a thermal shift.

FIG. 12 is an explanatory diagram of a pattern shift.

[Explanation of symbols]

 Reference Signs List 11 pulse width measurement unit 12 pulse interval measurement unit 13 first memory 14 second memory 15 first delay circuit 16 second delay circuit 17 flip-flop 21 controller 22 formatter 23 recording compensation circuit 24 LD drive system 25 optical head Reference Signs List 50 magneto-optical disk 61 counter 65 latch 66-69 D-type flip-flop 70 memory 81 programmable delay 91 multi-tap delay line 92 multiplexer

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-235236 (JP, A) JP-A-2-235235 (JP, A) JP-A-3-54739 (JP, A) JP-A-63- 48617 (JP, A) Japanese Utility Model 4-12124 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 11/00-13/06

Claims (4)

(57) [Claims] 1. A method for detecting a change in the amount of reflected light from a recording surface or a rotation of a reflection polarization surface to detect an intensity of an optical disk using a recording pulse according to a mark length recording method for an optical disk in which recorded information is reproduced. An optical disk recording apparatus for irradiating a modulated light beam to record and form information as intermittent rows of recording pits, comprising: a pulse width measuring unit (PULSE WIDTH measuring section) for measuring a pulse width of the recording pulse corresponding to a length of the recording pit. 11), a pulse interval measuring unit (12) for measuring a pulse interval of the recording pulse, and an output of the pulse width measuring unit (11) input as an address, and an edge shift amount to be corrected corresponding to the measured pulse width A first memory (13) for outputting the data of the above, and an output of the pulse interval measuring unit (12) is inputted as an address, and a correction corresponding to the measured pulse interval is provided. A second memory (14) for outputting data of a power edge shift amount, and a first delay pulse having a smaller delay amount as the measurement pulse width increases based on output data of the first memory (13). A first delay circuit (15) that outputs a second delay pulse having a larger delay amount as the measurement pulse interval becomes smaller, based on output data of the second memory (14). And a flip-flop that receives the first and second delay pulses at a set terminal and a reset terminal, respectively, and outputs a correction recording pulse for modulating the light intensity of the light beam from an output terminal. (17) An optical disc recording apparatus, comprising: 2. The first and second memories according to at least one of a recording track number, a medium sensitivity, and an environmental temperature of the optical disk.
2. The optical disk recording apparatus according to claim 1, further comprising a change unit (21) for changing each of the recording edge shift amount data. 3. The first and second delay circuits (15, 1).
6) The first and second memories (13, 14) respectively.
2. An optical disk recording apparatus according to claim 1, wherein said output data is a programmable delay that is input to a data terminal and generates and outputs a time-delayed delayed pulse corresponding to the input value of said data terminal. 4. The first and second delay circuits (15, 1).
6) A delay line (91) having a multi-tap structure for giving a plurality of delay times to the recording pulses and outputting the recording pulses from a plurality of output terminals, and the first and second memories (13, 14). 2. An optical disk recording apparatus according to claim 1, further comprising a multiplexer (92) for selectively outputting one of pulses from a plurality of output terminals of said delay line (91) in accordance with the output data of said delay line (91). .