JP2006048836A - Information recording method, laser driving circuit and information recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high-speed light output modulation for single/multi pulse and to improve the accuracy of light output resolution of a light source. <P>SOLUTION: When the light source is made to emit single pulse light by a single pulse signal and additional pulse light by an additional pulse signal for emitting pulse light with pulse duration different from that of the single pulse signal so that a recording medium 10 is irradiated with the emitted single pulse light and additional pulse light to form a record mark on a recording layer of the recording medium 10, and recording the information, a laser driver 6 optionally sets the on/off of the additional pulse signal in accordance with the recording rate of the recording medium 10, the length of the record mark or the length of spaces before and after the record mark. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention records information on an optical disk (recording medium) such as a CD-R disk, a CD-RW disk, a DVD-R disk, a DVD-RW disk, a DVD-RAM disk, a DVD + RW disk, and an MO disk. Method, laser drive circuit for controlling emission of laser light irradiated when recording information on the recording medium, CD-R drive device, CD-RW drive device, DVD-R drive device, DVD-RW The present invention relates to information recording devices such as drive devices, DVD-RAM drive devices, DVD + RW drive devices, and MO drive devices.

In recent years, with an increase in the amount of information, optical discs are expected as recording media (also referred to as media) capable of recording and reproducing data at high density and high speed. This optical disc has a write once type that can be recorded only once and a rewritable type that can be recorded and erased as many times as possible. The latter (rewritable type) includes a magneto-optical recording medium using the magneto-optical effect and a reversible crystal. There is a phase change type recording medium that utilizes a change in reflectance accompanying a change in state.
The recording principle of optical discs includes write-once media using drilling and deformation, magneto-optical media using magnetic reversal near the Curie point, and phase-change media using phase transition between the crystal and amorphous phase of the recording layer. In either case, the recording layer is heated to a predetermined temperature or higher by the irradiation power to the recording layer by a light source such as a laser diode (LD), and recording is performed by causing a physical or scientific change.

  For example, in a phase change type recording medium, a non-recorded / erased state (also called a space) is set in a normal crystalline state, and a recorded state (also called a mark) is set in an amorphous phase state. After the recording layer is heated to the melting point or higher by the irradiation power of the LD, the recording layer becomes an amorphous phase, that is, a mark when an appropriate cooling time is provided and the temperature is lowered (rapidly cooled) in a short time. . Further, the recording layer is crystallized and erased (erased) by increasing the time during which the temperature of the recording layer becomes the crystallization region by appropriate irradiation power of the LD.

On the other hand, almost all of these write-once media and phase-change media are recorded on a recording medium in recent years using mark length recording suitable for higher density.
Mark length recording is a method of recording data by changing the length of both the mark portion and the mark portion. However, since the time length of the mark is strictly detected in order to accurately reproduce the data, it is necessary to accurately control the shape of the mark edge.
There is also a difficulty in forming several types of marks having different lengths from short marks to long marks.
For example, in a DVD, the mark length to be recorded is composed of 10 types of 3T to 11T and 14T in units of a cycle T of a reference clock called WCK (26.16 MHz at the time of DVD 1 × speed).

The above-mentioned several types of mark length include an EFM (Eight to Four Modulation) modulation code (hereinafter referred to as EFM) as a general recording waveform for recording information. If this EFM signal is directly used as a recording waveform (that is, an LD emission waveform), in a long mark recording, the mark shape becomes tear-like as it goes backward from the mark due to heat accumulated from the front, and the reproduction quality deteriorates. There's a problem.
Therefore, a mark is formed on the recording medium by a multi-pulse LD light emission waveform (hereinafter referred to as a multi-pulse waveform) generated based on the EFM modulation code or the like to prevent the above problem.

33 and 34 are diagrams showing examples of general recording waveforms on a write-once medium such as a dye system.
In order to prevent the mark shape from being formed in a tear shape as described above when a mark shape having a length equal to the EFM data length determined from the user data is formed on the recording medium, FIG. 33 and FIG. A recording waveform as shown in FIG.
FIG. 33 shows a recording waveform when the mark length is short (for example, a mark having a length of 3T), which is the light output Pw for the light source LD to irradiate the recording medium with light to form an appropriate mark shape. It has a single pulse waveform consisting of a heating pulse and an optical output Pr for reading a wobble that is a guide groove that is a source of address information carved on the recording medium.

It comprises a light output rising timing width Ts that determines the mark length, that is, a leading mark shape necessary for controlling the mark shape, and a pulse center Ttop that determines the mark center portion and rear edge portion and the mark length.
Further, as shown in FIG. 34, a multi-pulse waveform may be used when the mark length is long (for example, a mark having a length of 10T). FIG. 34 shows an optical waveform when multipulses are used. 34 also includes Ts and Ttop for determining the leading mark shape, pulse width Tlp for determining the backward mark shape, and Tmp for forming the mark shape central portion.

Although the recording speed has been increased by the single pulse waveform and the multi-pulse waveform and the high-speed compatible recording medium as described above, the margin of the recording speed is approaching the limit as the recording medium.
In particular, with high-speed recording media, it is becoming difficult to widen the recording speed margin due to characteristics such as the sensitivity of the recording material. Unless the recording power accuracy is increased, each recording medium is compatible with high speed or low speed. Thus, the recording speed is limited.
That is, with the increase in speed, control of the light intensity to the recording medium at the time of writing has become important.

Therefore, in recent years, a technique for controlling the recording power at high speed and with high accuracy by dividing the recording power called a write strategy into pulses and multi-leveling the recording power has become essential. The LD driver that controls the LD optical output current with high-precision recording power control needs to switch a plurality of currents, and input signal lines increase.
In addition, it is expected that the pulse division width is further subdivided for further recording speed, and it is required to increase the number of multilevel levels of recording power.

Conventionally, an LD driving unit that supplies current to an LD via a switching unit with a plurality of current sources and a driving waveform restoring unit that restores and drives a driving waveform corresponding to a binarized signal recorded on a recording medium are the same. There has been a light source driving device (see, for example, Patent Document 1) provided in a light source driving integrated circuit.
Japanese Patent Laid-Open No. 11-283249

By the way, as the recording speed increases, the reference clock period T becomes shorter, and it has become difficult to perform recording with multipulses as in the past. High-speed recording has been supported by changing the length to a single pulse.
On the other hand, as shown in FIG. 35, the recording waveform by the conventional single pulse is such that the recording power PW is constant for all mark lengths, and a multiplication clock of the reference clock WCK is used to increase the resolution of the drive current. For example, the resolution of the recording power is increased by increasing the time resolution of the drive current timing phase Ts and the pulse width Ttop.

However, in the conventional light source driving apparatus, as described above, as the recording speed increases, the recording power margin necessary for forming a desired recording mark on the recording medium becomes narrower, and the optical pulse time resolution is improved. Therefore, there is a problem that it is difficult to form a desired recording mark.
The present invention has been made in view of the above points, and an object of the present invention is to realize high-speed light output modulation for single / multi-pulse and to improve the accuracy of light output resolution of a light source.

In order to achieve the above object, the present invention provides the following information recording methods (1) to (10).
(1) The light source emits single pulsed light by a single pulse signal and additional pulsed light by an additional pulse signal that emits pulsed light having a pulse time width different from the single pulsed signal. In an information recording method for recording information by irradiating a recording medium with additional pulsed light and forming a recording mark on a recording layer of the recording medium, the recording speed of the recording medium, the length of the recording mark, or An information recording method for arbitrarily setting on / off of the additional pulse signal according to the length of the space.

(2) The information recording method according to (1), wherein the additional pulse signal is a subtraction pulse signal that subtracts the light output of the light source from single pulse light by the single pulse signal.
(3) In the information recording method of (1) or (2), the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position.
(4) The information recording method according to any one of (1) to (3), wherein the additional pulse signal is a signal for arbitrarily setting a light output of the light source.

(5) In the information recording method according to any one of (1) to (4), the additional pulse signal includes a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal obtained by dividing the single pulse width. An information recording method which is a divided additional pulse signal.
(6) In the information recording method according to (5), the divided pulse signal at the head of the divided additional pulse signal is changed according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. An information recording method for setting on / off of at least one of a central division pulse signal and a rear division pulse signal.

(7) When recording information on a recording medium by causing a multi-pulse signal to be emitted from a light source by a multi-pulse signal composed of a leading pulse portion, a plurality of central pulse portions, and a rear pulse portion, At least one multi-addition pulse signal composed of a head additional pulse signal section, a central additional pulse signal section, and a rear additional pulse signal section is provided in each of the first pulse section, the plurality of central pulse sections, and the rear pulse section of the signal. In the information recording method for recording information by forming a recording mark on the recording layer of the recording medium by adding one, depending on the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces Then, on / off of any one of the leading additional pulse signal portion, the central additional pulse signal, and the rear additional pulse signal of the multi additional pulse signal is arbitrarily set. Broadcast recording method.

(8) The information recording method according to (7), wherein the multi-addition pulse signal is a subtraction pulse signal that subtracts the light output of the light source from the multi-pulse signal.
(9) In the information recording method of (7) or (8), the multi additional pulse signal includes a pulse time width of the head additional pulse signal portion, the central additional pulse signal portion, and the rear additional pulse signal portion. An information recording method which is a signal for arbitrarily setting at least one of pulse generation positions.
(10) In the information recording method of (7) or (8), the multi-addition pulse signal is a signal for arbitrarily setting the light output of the light source.

(11) An information recording method comprising at least any two of the following first to twenty-first steps.
The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, a first step of arbitrarily setting on / off of the additional pulse signal.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the second pulse is a subtracting pulse signal in which ON / OFF of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after In response, the additional pulse signal is arbitrarily set to ON / OFF, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse A fourth stroke which is a signal for arbitrarily setting at least one of the generation positions.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting the light output of the light source.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set. The additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the light output of the light source. 6th process which is a signal which sets up arbitrarily.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position, and light of the light source A seventh step which is a signal for arbitrarily setting the output.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a divided additional pulse composed of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal obtained by dividing the single pulse width. 8th process which is a signal.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the single pulse width is This is a divided additional pulse signal consisting of the divided head part divided pulse signal, center part divided pulse signal, and rear part divided pulse signal. Stroke of the ninth.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width or a pulse generation position, and the single pulse width. Is a divided additional pulse signal consisting of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal. Stroke.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse generation A signal that arbitrarily sets at least one of the positions, and a head portion obtained by dividing the single pulse width 11th stroke of a divided additional pulse signal consisting of split pulse signal and the central portion divided pulse signal and a rear section divided pulse signal.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a divided additional pulse composed of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal obtained by dividing the single pulse width. A signal, and the divided additional parameter according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Twelfth step of setting at least one on-off of the top portion divided pulse signal and the central portion divided pulse signal and a rear section divided pulse signal of the scan signals.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the single pulse width is This is a divided additional pulse signal consisting of the divided head part divided pulse signal, center part divided pulse signal, and rear part divided pulse signal. Depending on the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, the first divided pulse signal, the central divided pulse signal, and the rear divided pulse signal of the divided additional pulse signal A thirteenth step of setting at least one of them on / off.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width or a pulse generation position, and the single pulse width. Is a divided additional pulse signal composed of a head divided pulse signal, a central divided pulse signal, and a rear divided pulse signal. Depending on the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, one of the first divided pulse signal, the central divided pulse signal, and the rear divided pulse signal of the divided additional pulse signal. A fourteenth step of setting at least one on / off.

  The light source emits single pulse light by a single pulse signal and additional pulse light by an additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse generation A signal that arbitrarily sets at least one of the positions, and a head portion obtained by dividing the single pulse width A split additional pulse signal composed of a split pulse signal, a central split pulse signal, and a rear split pulse signal, depending on the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, A fifteenth step of setting on / off of at least one of the leading divided pulse signal, the central divided pulse signal, and the rear divided pulse signal of the divided additional pulse signal.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. A sixteenth step for arbitrarily setting ON / OFF of any one of the leading additional pulse signal portion, the central additional pulse signal, and the rear additional pulse signal of the signal.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of the leading additional pulse signal part, the central additional pulse signal, and the rear additional pulse signal of the signal is arbitrarily set on and off, and the multiple additional pulse signal , 17 strokes of a subtraction pulse signal for subtracting the light output of the light source to the multi-pulse signal.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of the leading additional pulse signal part, the central additional pulse signal, and the rear additional pulse signal of the signal is arbitrarily set on and off, and the multiple additional pulse signal , 18 strokes of a signal for setting arbitrarily at least one of the first additional pulse signal portion and the central additional pulse signal portion and the rear additional pulse signal unit, the pulse time width and the pulse generation position.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of the leading additional pulse signal part, the central additional pulse signal, and the rear additional pulse signal of the signal is arbitrarily set on and off, and the multiple additional pulse signal A subtracting pulse signal for subtracting the light output of the light source from the multi-pulse signal, and a pulse time width and a pulse generation position of the leading additional pulse signal portion, the central additional pulse signal portion, and the backward additional pulse signal portion. A nineteenth stroke which is a signal for arbitrarily setting at least one of the above.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of the leading additional pulse signal portion, the central additional pulse signal, and the rear additional pulse signal is set to ON / OFF, and the multi additional pulse signal is 20th stroke of a signal for setting arbitrarily the light output of the light source.

  When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. Accordingly, when recording information is formed by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of the leading additional pulse signal part, the central additional pulse signal, and the rear additional pulse signal of the signal is arbitrarily set on and off, and the multiple additional pulse signal A subtraction pulse signal for subtracting the light output of the light source to the multi-pulse signal, and the 21 strokes of a signal for setting arbitrarily the light output of the light source.

The following (12) laser drive circuit and (13) information recording apparatus are also provided.
(12) A laser drive circuit comprising means for executing the information recording method according to any one of (1) to (11) above.
(13) An information recording apparatus comprising the laser drive circuit of (12).

  The information recording method, laser driving circuit, and information recording apparatus according to the present invention can realize high-speed optical output modulation for single / multi-pulse and improve the accuracy of optical output resolution of the light source.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram showing a part of the entire configuration of an information recording / reproducing apparatus according to an embodiment of the present invention.
This information recording / reproducing apparatus is a recording medium (information recording medium) using an optical disc such as a CD-R disc, a CD-RW disc, a DVD-R disc, a DVD-RW disc, a DVD-RAM disc, a DVD + RW disc, and an MO disc. A CD-R drive device, a CD-RW drive device, and a DVD for recording or reproducing information (data) by irradiating a single pulse light emitted from a semiconductor laser light source (light source) 7 such as a laser diode (LD) -R drive devices, DVD-RW drive devices, DVD-RAM drive devices, DVD + RW drive devices, MO drive devices, and other optical disk drive devices that perform mark edge recording using EFM modulation codes.

Next, each part of the information recording / reproducing apparatus shown in FIG. 1 will be described.
The optical pickup 5 irradiates the recording medium 10 with light emitted from the light source (LD) 7 to record data (information), or receives reflected light with respect to the irradiation light from the recording medium 10 by the photodetector 8. A light receiving signal, a laser driver 6 for driving the LD 7 and the LD 7, a light receiving portion (not shown) for receiving the reflected light from the recording medium 10, and a monitor for receiving a part of the light emitted from the LD 7. An optical system (known and not shown) including a light detector 8 (not shown), a lens, a mirror, and the like that collect light emitted from the LD 7 onto the recording medium 10 is arranged. Has been.

Further, the variation in the amount of light emitted from the LD 7 is controlled from a monitor light receiving signal detected by a monitor light receiving unit (known and not shown) that monitors a part of the light emitted from the LD 7 disposed in the photodetector 8. The optical output Po output from the LD 7 can be generally obtained by the arithmetic processing based on the following equation 1 when the differential quantum efficiency η of the LD 7 is set, the LD threshold current is Ith, and the LD drive current Iop.
(Equation 1) Po = η (Iop−Ith)

  For example, the threshold current Ith at which the LD 7 obtained from the photodetector 8 starts light output is obtained, and auto power control (Auto Power Control: APC) is applied to the laser driver 6 so that Ibias = Ith. .

  Furthermore, a tilt detection light receiving unit (also known and not shown) for detecting a tilt (referred to as “tilt”) with respect to the irradiation light of the recording medium 10 may be arranged. Furthermore, in the case of an information recording / reproducing apparatus corresponding to a plurality of types of recording media in which different media formats are defined (for example, both DVD and CD compatible devices), each recording medium may have a light source with a suitable wavelength. In some cases, a light receiving unit and a monitor light receiving unit that receive reflected light from the recording medium when each light source is emitted are separately provided.

The signal processing unit 4 receives light reception signals from various light receiving units disposed in the optical pickup 5 and performs various signal processing.
For example, control is performed so that information is reproduced from the received light signal, or light is always irradiated within a predetermined error with respect to fluctuations such as surface vibration and track radial vibration accompanying rotation of the recording medium 10 (focus servo control). In addition, a servo error signal is generated from the received light signal for track servo control), and the optical pickup 5 is controlled in accordance with the servo error signal.
Further, the information to be recorded is modulated in accordance with a predetermined rule, and is output as a recording signal to the LD 7 (or the laser driver 6), or the output light quantity of the LD 7 is controlled.

  The spindle motor 9 rotates the recording medium 10, and the rotation speed is controlled (spindle servo control) by the signal processing unit 4. When performing CLV rotation control, a rotation control signal embedded in the recording medium 10 is detected via the optical pickup 5 in order to perform rotation control with higher accuracy, and rotation control is performed based on the rotation control signal. As the rotation control signal, for example, a reproduction information recording medium or the like uses a synchronization signal arranged at a predetermined interval on recorded information, or a wobble or the like where a recording track meanders at a predetermined frequency in a recordable information recording medium.

For example, the controller 3 can record information to be recorded and reproduced with the host computer 1 via an interface control circuit 2 that conforms to a standard such as SCUGY (Small Computer System Interface: SCSI) or ATTACHED (AT Attached Packet Interface: ATAPI). The entire device is controlled by passing and command communication.
Since the optical pickup 5 is movable in the radial direction of the recording medium 10 (this operation is called “seek operation”), the circuit board on which the optical pickup 5 and the signal processing unit 4 are mounted is a flexible printed circuit ( It is generally connected by a board (or cable) called a flexible print circuit (FPC) board (or cable), and components mounted on the optical pickup 5 such as the LD 7 and the photodetector 8 are mounted on this FPC board. Often done.

Next, the internal configuration of the laser driver 6 for realizing the strategy output according to the present invention in the information recording / reproducing apparatus will be described.
FIG. 2 is a block diagram showing an internal configuration of the laser driver 6 shown in FIG. 1, and the same reference numerals are given to portions common to FIG.
The laser driver 6 includes a clock generation unit 20, a mark / space length detection unit 21, a timing control unit 22, a recording waveform setting value storage unit 23, a drive current generation unit (drive current control unit) 24, and a control interface (I / F). 25.

[Clock Generator 20]
The clock generator 20 generates a reference clock signal WCK serving as a reference for the data length of the EFM signal and recording clock signals STCK0 to STCK7 for controlling strategy parameters. The reference clock signal WCK and the recording clock signals STCK0 to STCK7 are inputted with the sine wave signal WBLCK generated by the wobbling of the guide groove carved in the recording medium, binarized, etc., multiplied, divided, shifted, etc. A reference clock signal WCK suitable for the recording speed is generated and output by a generated recording clock, a frequency divider, or the like.

FIG. 6 is a block diagram showing an internal configuration of the clock generator 20 shown in FIG.
As shown in FIG. 6, the clock generation unit 20 includes a reference clock generation unit 200 and a recording clock generation unit 220. The reference clock generation unit 200 includes a first frequency divider 210, a phase comparator 211, a filter 212, The recording clock generation unit 220 includes a third frequency divider 221 including a frequency divider 213 and a VCO 214.

  Further, as shown in FIG. 3A, the clock generation unit 20 includes a multiplied clock generation unit 201 that outputs a signal NCK obtained by multiplying the input sine wave signal WBLCK as a recording clock signal. (An example of the sine wave signal WBLCK and the signal NCK is shown in (b) of FIG. 3), and as shown in (a) of FIG. / NCK may be output as a recording clock signal (an example of the sine wave signal WBLCK and the signal NCK is shown in FIG. 7B).

  Further, as shown in FIG. 4A, a recording clock generation unit 202 may be provided, and a signal SFTCK obtained by shifting the phase of these signals may be output as a recording clock signal ((( b) shows an example of the sine wave signal WBLCK and the signals SFTCK0 to SFTCK7), and as shown in FIG. 5A, the recording clock generation unit 203 is provided, and the period of these signals is halved. Alternatively, the signal STCK may be output (an example of the sine wave signal WBLCK and the signals STCK0 to STCK7 is shown in FIG. 5B).

  The recording clock signal and the reference clock signal WCK, which are signals generated by the clock generation unit 20, are output to the recording waveform setting value storage unit 23, the timing control unit 22, and the mark / space length detection unit 21 to store the recording waveform setting value. Used as an operation clock for the unit 23 and the timing control unit 22.

FIG. 6 is a diagram illustrating a configuration using a phase locked loop (PLL) circuit as an example of the clock generation unit 20.
An internal feedback signal obtained by dividing the input sine wave signal WBLCK as a reference signal, output from a voltage-controlled oscillator (VCO) 214, and frequency-divided by 1 / N by a second frequency divider 213. And A phase difference between the reference signal and the internal feedback signal is detected by a phase comparator 211, and the phase difference is fed back to the VCO 214 as a voltage for control. Further, the recording clock signals STCK0 to STCK7 obtained by shifting the internal feedback signal by M / 8 phase and the reference clock signal WCK suitable for the recording speed are output. The settings of the first frequency divider 210 and the second frequency divider 213 can be changed by the controller 3.

[Mark / space length detector 21]
The mark / space length detection unit 21 inputs user data as information to the recording medium 10 via the controller 3 and the signal processing unit 4 as an EFM signal, and converts the detected EFM space / mark length into a desired optical output. In order to call a necessary strategy setting value, it is sent to the recording waveform setting value storage unit 23.

[Recording Waveform Setting Value Storage Unit 23]
The recording waveform setting value storage unit 23 is a part that stores a recording waveform shape setting value. The set value stores a set value of each D / A converter (hereinafter referred to as DAC) that determines a strategy parameter and an optical output to be described later. The stored strategy parameters and DAC set values are changed from the data sent from the controller 3 via the control I / F 25 (for example, serial I / F). In addition, a setting value that determines the shape of a recording waveform for forming a desired mark shape from EFM mark / space length data input from the mark / space length detection unit 21 is called to the storage timing control unit 22. Output. The strategy parameter and the DAC set value are set according to the recording speed, the recording medium, and the mark space length signal input from the mark / space length detection unit 21.

[Timing control unit 22]
The timing control unit 22 is input from the recording clock signal (for example, STCK0 to STCK7) and the reference clock signal WCK input from the clock generation unit 20, the EFM input from the signal processing unit 4, and the recording waveform setting value storage unit 23. A strategy control signal for forming a desired strategy is generated and output according to a strategy parameter setting value to be described later.
The strategy control signals are, for example, the digital signals PWEN, P1EN, P2EN, PUEN, and PREN shown in FIGS.

The strategy control signal is generated by each of the strategy control signal generation circuits PWENGen230, P1ENGen231, P2ENGen232, PUENGen233, and PREGENGen234 that incorporates a counter using the recording clock signal STCK as a clock, and a drive current generator that generates a drive current to the LD7 To 24.
Further, since the signal output from the timing controller 22 to the drive current generator 24 is modulated at high speed, the timing controller 22 and the drive current generator 24 may be connected by a differential signal such as LVDS. Further, by using the differential signal, there is an effect of reducing the skew between signals and improving the noise resistance of the signal.

[Driving current generator 24]
FIG. 9 is a block diagram showing an example of the internal configuration of the drive current generator 24 shown in FIG.
The drive current generation unit 24 includes a plurality of D / A converters PWDAC 241, P1 DAC 242, P2 DAC 243, PUDAC 244, and PRDAC 245 in order to generate a strategy according to the present invention.
In the figure, Ibias sets the bias current Ibias of the LD 7, and APC is applied so that Ibias = Ith as described above, and is input from the optical pickup 5. The PWDAC 241 is a DAC for emitting the optical output PW used in the conventional single pulse waveform. The PRDAC 245 is a DAC for emitting an optical output PR for reading information on the recording medium 10 used in the conventional strategy.

Further, the P1 DAC 242, the P2 DAC 243, and the PUDAC 244 are DACs for outputting the strategy addition pulses P1 and P2 and the subtraction pulse PU, respectively.
In addition, the timing control unit 22 outputs strategy control signals PWEN, P1EN, P2EN, PUEN, and PREN to control the switches that control the outputs of the PWDAC 241, P1 DAC 242, P2 DAC 243, PUDAC 244, and PRDAC 245. The output current and bias current from each of these PWDAC 241, P1 DAC 242, P2 DAC 243, PUDAC 244, and PRDAC 245 are added and subtracted by the current addition circuit 240 and output to the LD 7.

  Further, as described above, the clock generation unit 20, the mark / space length detection unit 21, the recording waveform set value recording unit 23, and the timing control unit 22 are digital units that operate at high speed, so that they have a fine CMOS process (for example, 0.18 μ). The drive current generator 24 uses a high-breakdown-voltage process to drive the LD 7 to emit light, and can be realized as a single chip, so that high-speed operation and high breakdown voltage can be realized simultaneously. Further, it is possible to reduce the skew between the strategy control signals by using one chip.

Next, a recording waveform rule (hereinafter referred to as strategy) output from the laser driver 6 of the information recording / reproducing apparatus will be described.
The strategy includes, for example, a single pulse used when the mark length is short (eg, 3T mark, hereinafter referred to as short mark), and a multi-pulse used when the mark length is long (eg, 14T mark, hereinafter referred to as long mark). There is.
First, a configuration example necessary for carrying out the single pulse strategy which is the first example of the strategy will be described with reference to FIGS. 8, 9 and 10.
FIG. 8 is a block diagram showing an example of the configuration of the timing controller 22, FIG. 9 is a block diagram showing an example of the configuration of the drive current generator 24, and FIG. 10 shows an example of the waveform of the single pulse strategy. FIG.

  Each strategy control signal PWEN, P1EN, P2EN, PUEN, PREN controls on / off of each of the switches SW1 to SW5 between the PWDAC241, P1DAC242, P2DAC243, PUDAC244, PRDAC245 and current adding circuit 240 shown in FIG. .

  When the switches provided in each of the PWDAC 241, P1 DAC 242, P2 DAC 243, PUDAC 244, and PRDAC 245 are turned on, a current based on the DAC setting value set via the control I / F 25 as described above is output, and the PWDAC 241, The currents output from the P1 DAC 242, the P2 DAC 243, the PUDAC 244, and the PRDAC 245 are added (subtracted) by the current adding circuit 240 together with the bias current Ibias that is equal to the threshold current Ith calculated from the photodetector 8, for example. The drive current generated from the adder circuit 240 is input to the LD 7.

FIG. 10 shows the light output by the input drive current.
As shown in FIG. 10, the optical output Pbias is an optical output based on the Ibias current value, and the optical outputs PW, PR, P1, P2, and PU are optical outputs from the PWDAC 241, P1 DAC 242, P2 DAC 243, PUDAC 244, and PRDAC 245, respectively. However, the current value from PUDAC 244 is subtracted, and the current values from other DACs are added.

On the other hand, the shape of each strategy control signal such as PWEN is determined by strategy parameters TSS, TSP, TLS, TLP, TSO, TLU, TCL, and MET, MEM, MEL as shown in FIG.
The strategy parameters are set and stored for each EFM mark / space length in the recording waveform set value storage unit 23 and input to each strategy control signal generation circuit in the timing control unit 22.
Each of the strategy control signal generation circuits has a built-in counter that uses a recording clock (for example, STCK0 to STCK7) input from the clock generation unit as a clock, and is determined by each strategy parameter.

Next, the shape of the strategy control signal based on each strategy parameter will be described.
The strategy control signal PWEN rises with a delay corresponding to the TSS set value from the EFM rise timing, and the pulse width is set to TLS + TLP + (n−3) T (where n is the mark length and T is the reference clock period).

The strategy control signal P1EN is divided into three sections: a head division pulse P1top, a central division pulse P1mid, and a rear division pulse P1last. The pulse width of each section is TSP, TLS + (n−3) T−TSS−TSP−TLP, TLP, and each divided pulse can be turned on and off by MET, MEM, and MEL.
For example, FIG. 10 shows a case in which MET = 1, MEM = 1, and MEL = 0 are set, and the rising timing of the head division pulse coincides with PWEN.

As with the strategy control signal P1EN, the strategy control signal P2EN is divided into three sections: a head division pulse P2top, a central division pulse P2mid, and a rear division pulse P2last. The pulse width of each section is TSP, TLS + (n−3) T−TSS−TSP−TLP, TLP, and each divided pulse can be turned on and off by MBT, MBM, and MBL.
For example, FIG. 10 shows a case where MBT = 1, MBM = 0, and MBL = 0, and the leading edge division pulse rise timing coincides with PWEN.

The rising timing of the strategy control signal PUEN coincides with the falling timing of the strategy control signal PWEN, and the pulse width is set by the TLU setting value. When TLU = 0, PUEN is fixed to L.
The strategy control signal PREN is fixed to H when MRC = 0, but when MRC = 1 is set, the strategy control signal PREN becomes low “L” in accordance with the falling timing of the strategy control signal PWEN, and the pulse width thereof is the TCL set value. Set by.

Next, the single pulse strategy which is the first embodiment of the strategy according to the present invention will be described in detail.
Conventional information recording methods include a mark position recording method and a mark edge recording method. In particular, a mark edge recording method capable of increasing the density has been adopted in recent years.
In the mark edge recording method, since the mark length accuracy and the mark shape on the recording medium determine the reproduction quality, the position accuracy at both ends of the recording mark and the shape of the central portion of the recording mark are important.
Therefore, the strategy according to the present invention will be described in detail by taking a single pulse shape as an example by dividing it into a head mark shape, a rear mark shape, and a center mark shape.

i) Strategy head part pulse An important point in the head part mark shape formation is the mark position accuracy. Particularly in the formation of the head mark shape, the heat accumulation on the recording medium due to the mark length and space length immediately before the mark to be recorded and the recording power margin due to the sensitivity characteristics of the recording medium compatible with high-speed recording as described above are narrowed. Therefore, it is necessary to improve the time resolution as shown in FIG. 35 as a conventional example and to perform high-speed optical output modulation.

So in the top mark shape,
(1) Improvement of time resolution of single pulse and addition pulse by strategy parameter TSS and TSP (2) Desired head mark shape can be obtained by high-speed optical output modulation by addition pulse using strategy parameter MET and MBT .
That is, by setting the ON / OFF of MET and MBT individually according to the recording speed, the length of the recording mark to be recorded, and the length of the immediately preceding space, it is possible to modulate the optical output of the leading pulse at a high speed of 4 bits. TSS and TSP have the effect of improving the resolution of optical output.
Further, as shown in FIG. 11, the pulse width of P2EN in the addition pulse is set by TSO, and ON / OFF (for example, OFF when TSO = 0) is determined by the set value of TSO.
Thereby, there is an effect of improving the resolution of the optical output by the strategy control signal P2EN.

That is, as shown in FIG. 12 and FIG. 13, the laser drive circuit is simplified by omitting the addition pulse P2DAC, or by further turning on the MEM as shown in FIG. Can be modulated.
Furthermore, as shown in FIGS. 14 and 15, individual optical outputs and pulse time widths can be modulated at high speed.
As described above, FIG. 16 has an effect of improving the resolution of the optical output by the strategy control signal P2EN by turning on and off (for example, off when TSO = 0) according to the set value of TSO.

ii) About the strategy rear part pulse As with the head part pulse described above, the important point in the rear part make shape is the mark position accuracy and shape. In particular, the rear mark shape must take into account the effect on the space length immediately after and the next mark length. Further, as described above, improvement in time resolution and high-speed optical output modulation are required.

Therefore, in the rear mark shape, as shown in FIG. 10, (1) Improvement of time resolution of single pulse light and addition pulse by strategy parameters TLS and TLP (2) High-speed optical modulation by addition of addition pulse by strategy parameters MEL and MBL Further, in the rear part of the strategy, PUDAC and PRDAC for subtracting the optical output (3) Improvement of time resolution of the subtraction pulse by the strategy parameters TLU and TCL (4) High-speed optical modulation (subtraction) by the strategy parameter MRC
Thus, a desired rear mark shape can be obtained.

  That is, it is possible to modulate the optical output of the rear pulse at a high speed by 4 bits by individually setting on / off of MEL and MBL according to the recording speed, the length of the recording mark to be recorded and the space length immediately after the recording mark. TLS and TLP have the effect of improving the optical output resolution. Furthermore, high-precision optical output resolution can be obtained by subtracting the optical output by the D / A converters PUDAC and PRDAC. The strategy control signal PUEN can be set to ON / OFF (eg, OFF when TLU = 0) according to the set value of the pulse width TLU.

Further, as shown in FIGS. 17 and 18, the laser drive circuit is simplified by omitting the addition pulse P2DAC as in the head portion, or the MEL is turned on as shown in FIG. The optical output can be modulated in the time direction.
Further, as shown in FIGS. 19 and 20, it is possible to modulate the individual optical output and the pulse time width at high speed. Furthermore, as described above, as shown in FIGS. 21 and 22, a highly accurate optical output resolution can be obtained by the subtraction pulse.
Further, the strategies shown in FIGS. 23 to 26 can be obtained by combining the above-described mark shape formation at the head and rear portions.

iii) About the central mark shape The important point in the formation of the central mark shape is that the mark shape spreads on the teardrop due to the accumulation of heat on the recording medium, or conversely the shape due to insufficient heat applied. It is to control the central pulse so that it cannot.
Therefore, in the central mark shape, (1) improvement of time resolution of single pulse light and addition pulse by strategy parameters TSP, TLS and TLP (2) desired central portion by high-speed optical modulation by addition of addition pulse by strategy parameters MEM and MBM A mark shape can be obtained.

That is, it is possible to modulate the optical output of the central pulse at a high speed by 4 bits by individually setting on / off of MEM and MBM according to the recording speed and the recording mark length to be recorded, and further, TSP, TLS, TLP This has the effect of improving the resolution of the added pulsed light output.
As shown in FIGS. 27 to 29, the optical output of the central pulse can be modulated at a high speed by 4 bits by individually setting the on / off of MEM and MBM.

Next, the effect of the single pulse described above will be described.
The pulse width set by the strategy parameters TSS, TSP, TLS, TLP, TSO, TLU and the MET, MEM, MEL, MBT, MBM, MBL are set according to the recording speed, the recording mark, and the space before and after. This can be implemented by turning on and off the strategy control signal according to the above, and enables faster optical modulation and pulse time width modulation.

In addition, the MRC setting of the PUDAC and the PRDAC can be implemented, and high-speed optical modulation and pulse time width modulation can be performed by setting the MRC and TLU according to the recording speed, the recording mark, and the space before and after. It becomes possible.
Furthermore, it can be implemented by setting the strategy parameters TSS, TSP, TLS, TLP, TSO, TLU, and by setting the strategy parameters according to the recording speed, the recording mark, and the space before and after, a highly accurate pulse Time width modulation is possible.
In addition, DACs corresponding to each strategy control signal, that is, PWDAC, P1DAC, P2DAC, PUDAC, PRDAC, can be implemented by setting each DAC setting value, depending on the recording speed, recording mark, and space before and after Thus, it is possible to obtain a high-precision optical output accuracy by setting each DAC.

Furthermore, it can be implemented by setting the above MET, MEM, MEL, MBT, MBM, MBL according to the recording speed, the recording mark and the space before and after, enabling faster optical modulation and pulse time width modulation. It becomes.
Further, as shown in FIG. 13, for example, as shown in FIG. 13, the pulse time width is changed at high speed by setting the MET, MEM, MEL, MBT, MBM, and MBL according to the recording speed, the recording mark, and the space before and after. Thus, faster optical modulation and pulse time width modulation are possible.

Next, a multipulse strategy which is the second embodiment of the strategy according to the present invention will be described in detail.
A configuration example necessary for implementing the multi-pulse strategy will be described with reference to FIGS. 30 and 31. FIG.
FIG. 30 is a block diagram showing an example of the configuration of the timing control unit 22, and FIG. 31 is a waveform diagram showing an example of the waveform of the multi-pulse strategy. The configuration of the drive current generator 24 is the same as that shown in FIG.
The implementation configuration of the multi-pulse strategy is an extension of the single pulse strategy for each multi-pulse, and a strategy parameter is added to output the multi-pulse.

Next, the shape of the multi-strategy control signal according to each strategy parameter will be described.
The strategy control signal PWEN rises with a delay corresponding to the TSS set value from the EFM rising timing, the leading heating pulse width is TSP, the leading cooling pulse is TFS, the central heating pulse width is TMP, the central cooling pulse width is TMP, the central part The number of heating and cooling pulses is set to NMP, the rear pulse rising timing is set to TLS + TLP + (n−3) T (where n is the mark length and T is the reference clock cycle), and the rear heating pulse width is set to TLP.
The pulse width of the strategy control signal P1EN is composed of a leading additional pulse signal portion, a central additional pulse signal portion, and a backward additional pulse signal portion, and each pulse width is the same as the heating pulse width of PWEN. Moreover, each pulse signal part can be set to ON / OFF by MET, MEM, and MEL.

Like the strategy control signal P1EN, the strategy control signal P2EN is composed of a head additional pulse signal section, a center additional pulse signal section, and a rear additional pulse signal section, but each pulse width is set by TSO, TMO, and TLO. . The ON / OFF setting for each pulse signal section is OFF when TSO, TMO, and TLO are set to 0.
The rising timing of the strategy control signal PUEN coincides with the falling timing of each pulse of the strategy control signal PWEN, and the pulse width is set by setting values of TSU, TMU, and TLU. Each pulse signal section is turned off when TSO, TMO, and TLO are set to 0.
The strategy control signal PREN is fixed to high “H” when MRC = 0, but when MRC = 1 is set, it becomes L in accordance with the trailing edge falling timing of PWEN, and its pulse width is the TCL set value. Is set.

Next, the multipulse strategy will be described in detail.
Conventional information recording methods include a mark position recording method and a mark edge recording method, and in recent years, a mark edge recording method capable of increasing the density has been adopted. In the mark edge recording method, since the mark length accuracy and the mark shape on the recording medium determine the reproduction quality, the position accuracy at both ends of the recording mark and the shape of the central portion of the recording mark are important.
Therefore, the details of the strategy will be described by taking the single pulse shape as an example by dividing the strategy into three parts of the head mark shape, the rear mark shape, and the center mark shape, similarly to the single pulse strategy.

i) Strategy head part pulse An important point in the head part mark shape formation is the mark position accuracy. Particularly in the formation of the head mark shape, the heat accumulation on the recording medium due to the mark length and space length immediately before the mark to be recorded and the recording power margin due to the sensitivity characteristics of the recording medium compatible with high-speed recording as described above are narrowed. Therefore, it is necessary to improve the time resolution and perform high-speed optical output modulation.
So in the top mark shape,
(3) Improvement of multi-pulse head pulse by strategy parameter TSS and TSP and addition pulse time resolution by TSO and TSP (4) Desired head mark by high-speed optical output modulation by addition pulse using strategy parameters MET and TSO It is possible to obtain a shape.

That is, it is possible to modulate the optical output of the leading pulse at high speed by individually setting the ON / OFF of the MET according to the recording speed, the recording mark length to be recorded, and the immediately preceding space length, and further by TSS and TSP. There is an effect of improving the resolution of light output.
Furthermore, as shown in FIG. 31, the pulse width of the strategy control signal P2EN in the addition pulse is set by TSO, and ON / OFF (eg, OFF when TSO = 0) is determined by the set value of TSO. Thereby, there is an effect of improving the resolution of the optical output by the strategy control signal P2EN.

ii) About the strategy rear part pulse As with the head part pulse described above, the important point in the rear part make shape is the mark position accuracy and shape. In particular, the rear mark shape must take into account the effect on the space length immediately after and the next mark length. Further, as described above, improvement in time resolution and high-speed optical output modulation are required.

Therefore, in the rear mark shape, as shown in FIG. 10, (5) Improvement of time resolution of multipulse rear light by strategy parameters TLS and TLP and addition pulse by TLP and TLO (6) By addition pulse addition by strategy parameter MEL High-speed optical modulation Further, in the rear part of the multipulse, D / A converters PUDAC and PRDAC for subtracting the optical output (7) Improving the time resolution of the subtraction pulse by the strategy parameters TLU and TCL (8) High-speed optical modulation by the strategy parameter MRC ( Subtraction)
Thus, a desired rear mark shape can be obtained.

  That is, it is possible to modulate the optical output of the rear pulse at high speed by setting on / off of the MEL according to the recording speed, the length of the recording mark to be recorded and the space length immediately after the recording, and further the optical output by TLS and TLP. This has the effect of improving the resolution. Furthermore, high-precision optical output resolution can be obtained by subtracting the optical output by the D / A converters PUDAC and PRDAC. Further, it is assumed that the strategy control signal PUEN can be set on / off (for example, off when TLU = 0) according to the set value of the pulse width TLU.

iii) About the central mark shape The important point in the formation of the central mark shape is that the mark shape spreads on the teardrop due to the accumulation of heat on the recording medium, or conversely the shape due to insufficient heat applied. It is to control the central pulse so that it cannot.
Therefore, in the central mark shape, (3) improvement in time resolution of multi-pulse light by strategy parameters TFS, TMP, TMS and addition pulse by TMP, TMO (4) high-speed optical modulation by addition of addition pulses by strategy parameters MEM, TMO ( 5) Setting of the phase and number of pulses of the central pulse by the strategy parameters TFS and NMP (6) By setting the cycle of the central pulse by the strategy parameters TMP and TMS, a desired central mark shape can be obtained.

That is, it is possible to modulate the light output of the central pulse at high speed by individually setting the MEM on / off according to the recording speed and the recording mark length to be recorded, and further, the center by TFS, TMP, TMS, NMP. The phase, period, and number of pulses of the partial pulse can be set, and the addition pulse can be turned on / off by TMO. In addition, there is an effect of improving the optical output resolution by setting the time resolution of multipulses and addition pulses by TFS, TMP, TMS, TMP, and TMO.
Further, as shown in FIG. 32, by setting the set value of the D / A converter P2DAC to erase power PE for erasing the recording mark on the phase change type recording medium, the multi-pulse strategy can be applied to the phase change type recording medium. Yes.

Next, the effect of multipulse will be described.
The strategy control signal P2EN, which is set by the strategy parameters TSO, TMO, TLO, TSU, TMU, TLU, and TCL, is turned on / off, and the MET, MEM, and MEL are set according to the recording speed, recording mark, and front and rear spaces. On / off setting of the strategy control signal P1EN of the strategy control signal set by the above can be arbitrarily turned on / off, and higher-speed optical modulation and pulse time width modulation can be performed.

Moreover, it can be implemented by providing the MRC settings of the D / A converters PUDAC and PRDAC, and high-speed optical modulation and pulse time width modulation of each pulse is possible according to the recording speed, recording mark, and front and rear spaces. It becomes.
Furthermore, it can be implemented by setting the strategy parameters TSS, TSP, TFS, TMP, TMS, NMP, TLS, TLP, TSO, TMO, TLO, TSU, TMU, and TLU. By setting the strategy parameter according to the space, highly accurate pulse time width modulation can be performed.

In addition, D / A converters corresponding to each strategy control signal, that is, PWDAC, P1DAC, P2DAC, PUDAC, PRDAC, can be implemented by setting each DAC setting value. By setting each of the DACs according to the space, it is possible to obtain high-precision light output accuracy.
Further, the difference between the configurations of the single pulse strategy and the multi-pulse strategy can be realized by adding the strategy parameter as described above. Therefore, the strategy parameters TFS, TMP, TMS, NMP, TMO, TLO not used in the single pulse strategy are used. When TSU and TMU are set to 0, switching from multi-pulse to single pulse is possible, so that single pulse and multi-pulse can be switched according to recording speed, recording mark length, and front and back space length. A strategy with a high degree of freedom for obtaining the mark shape can be realized.

  If the information recording method according to the present invention is processed by the laser driver 6 shown in FIGS. 1 and 2, and the laser driver 6 is provided in the information recording / reproducing apparatus, a wider range of recording speeds and A laser driving circuit and an information recording apparatus that can obtain a desired mark shape on a recording medium can be realized.

  An information recording method, a laser drive circuit, and an information recording device according to the present invention are a CD-R drive device, a CD-RW drive device, a DVD-R drive device, a DVD-RW drive device, a DVD-RAM drive device, a DVD + RW drive device, an MO The present invention can also be applied to an information recording device such as a drive device.

It is a block diagram which shows the structure of the information recording device of one Embodiment of this invention. It is a block diagram which shows the structural example of the laser driver shown in FIG. FIG. 2 is a waveform diagram of an internal configuration example of the clock generation unit shown in FIG. 1 and its output signal. FIG. 5 is a waveform diagram of another internal configuration example of the clock generation unit shown in FIG. 1 and its output signal. FIG. 4 is a waveform diagram of still another configuration example of the clock generation unit shown in FIG. 1 and its output signal.

FIG. 10 is a block diagram illustrating still another configuration example of the clock generation unit illustrated in FIG. 1. FIG. 4 is a waveform diagram of still another configuration example of the clock generation unit shown in FIG. 1 and its output signal. FIG. 3 is a block diagram illustrating a configuration example for implementing a single pulse strategy in the timing control unit illustrated in FIG. 2. FIG. 3 is a block diagram illustrating a configuration example for performing single and multi-pulse strategies in the drive current generation unit illustrated in FIG. 2.

It is a figure which shows the single pulse strategy optical waveform example which is the 1st Example of this invention. It is a figure which shows another example of the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired head mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired head mark shape by the single pulse strategy optical waveform which is the 1st Example of this invention similarly.

It is a figure which shows the example of a waveform for obtaining a desired head mark shape by the single pulse strategy optical waveform which is the 1st Example of this invention similarly. It is a figure which shows the example of a waveform for obtaining a desired head mark shape by the single pulse strategy optical waveform which is the 1st Example of this invention similarly. It is a figure which shows the example of a waveform for obtaining a desired head mark shape by the single pulse strategy optical waveform which is the 1st Example of this invention similarly.

It is a figure which shows the example of a waveform for obtaining a desired back mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired back mark shape similarly with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired back mark shape similarly with the single pulse strategy optical waveform which is the 1st Example of this invention.

It is a figure which shows the example of a waveform for obtaining a desired back mark shape similarly with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform which added the subtraction pulse in order to obtain a desired back mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform which added the subtraction pulse in order to obtain a desired back mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention similarly. It is a figure which shows the example of a waveform for obtaining a desired head and back mark shape simultaneously with the single pulse strategy optical waveform which is the 1st Example of this invention.

It is a figure which shows the example of a waveform for obtaining a desired head and back mark shape simultaneously with the single pulse strategy optical waveform which is the 1st Example of this invention similarly. It is a figure which shows the example of a waveform for obtaining a desired head and back mark shape simultaneously with the single pulse strategy optical waveform which is the 1st Example of this invention similarly. It is a figure which shows the example of a waveform for obtaining a desired head and back mark shape simultaneously with the single pulse strategy optical waveform which is the 1st Example of this invention similarly.

It is a figure which shows the example of a waveform for obtaining a desired center part mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired center part mark shape with the single pulse strategy optical waveform which is the 1st Example of this invention. It is a figure which shows the example of a waveform for obtaining a desired center part mark shape similarly with the single pulse strategy optical waveform which is the 1st Example of this invention.

It is a block diagram which shows the structural example of the timing control part for implementing the multipulse strategy which is the 2nd Example of this invention. It is a figure which shows the example of a multipulse strategy optical waveform which is the 2nd Example of this invention. It is a figure which shows the example of a waveform at the time of applying the multipulse strategy optical waveform which is the 2nd Example of this invention to a phase change type recording medium.

It is a figure which shows an example of the recording waveform by the conventional single pulse. It is a figure which shows an example of the recording waveform by the conventional multipulse. It is a figure which shows an example of the recording waveform when aiming at the time resolution improvement of the recording waveform by the conventional multiplication clock.

Explanation of symbols

1: Host computer 2: Interface control circuit 3: Controller 4: Signal processing unit 5: Optical pickup 6: Laser driver 7: Light source (LD) 8: Light detector 9: Spindle motor 10: Recording medium 20: Clock generation unit 21 : Mark / space length detection unit 22: Timing control unit 23: Recording waveform setting value storage unit 24: Drive current generation unit 25: Control interface (I / F) 200: Reference clock generation unit 201: Multiplication clock generation units 202 and 203 204: Recording clock generation unit 210: First frequency divider 211: Phase comparator 212: Filter 213: Second frequency divider 214: VCO 220: Recording clock generation unit 221: Third frequency dividers 230-234, 230 '-234': Strategy Control signal generating circuit 240: the current adding circuit 241 to 245: D / A converter

Claims (13)

The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. In an information recording method of recording information by irradiating a recording medium and forming a recording mark on a recording layer of the recording medium,
An information recording method, wherein the additional pulse signal is arbitrarily set on and off in accordance with a recording speed of the recording medium, a length of the recording mark, or a length of a front and rear space.   2. The information recording method according to claim 1, wherein the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal.   3. The information recording method according to claim 1, wherein the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position.   The information recording method according to any one of claims 1 to 3, wherein the additional pulse signal is a signal for arbitrarily setting a light output of the light source.   5. The additional pulse signal according to any one of claims 1 to 4, wherein the additional pulse signal is a divided additional pulse signal composed of a leading part divided pulse signal, a central part divided pulse signal, and a rear part divided pulse signal obtained by dividing the single pulse width. The information recording method according to claim 1.   According to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, among the leading part divided pulse signal, the central part divided pulse signal, and the rear part divided pulse signal of the divided additional pulse signal 6. The information recording method according to claim 5, wherein at least one of on and off is set. When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. In an information recording method for recording information by forming a recording mark on the recording layer of the recording medium,
According to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, any one of the leading additional pulse signal portion, the central additional pulse signal, and the rear additional pulse signal of the multi additional pulse signal An information recording method characterized by arbitrarily setting one of these on / off.   8. The information recording method according to claim 7, wherein the multi-addition pulse signal is a subtraction pulse signal that subtracts the light output of the light source from the multi-pulse signal.   The multi additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position of the head additional pulse signal section, the central additional pulse signal section, and the rear additional pulse signal section. 9. The information recording method according to claim 7 or 8, wherein:   9. The information recording method according to claim 7, wherein the multi-addition pulse signal is a signal for arbitrarily setting a light output of the light source. The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after In response, a first step of arbitrarily setting on / off of the additional pulse signal;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the additional pulse signal is arbitrarily set on and off, and the additional pulse signal is a subtracting pulse signal that subtracts the light output of the light source from the single pulse light by the single pulse signal;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after In response, the additional pulse signal is arbitrarily set to ON / OFF, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse A fourth stroke which is a signal for arbitrarily setting at least one of the generation positions;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting the light output of the light source;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal that subtracts the light output of the light source from the single pulse light by the single pulse signal, and the light output of the light source A sixth step which is a signal for arbitrarily setting
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position, and light of the light source A seventh step which is a signal for arbitrarily setting the output;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a divided additional pulse composed of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal obtained by dividing the single pulse width. An eighth step as a signal;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the single pulse width is set. It is a divided additional pulse signal consisting of a divided first part divided pulse signal, central part divided pulse signal, and rear part divided pulse signal. And the stroke of 9,
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the additional pulse signal is arbitrarily set to ON / OFF, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position, and the single pulse width. Is a divided additional pulse signal consisting of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal. And stroke,
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal that subtracts the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse generation It is a signal for arbitrarily setting at least one of the positions, and the leading portion obtained by dividing the single pulse width An eleventh step of a split additional pulse signal including a pulse signal and a central portion divided pulse signal and a rear section divided pulse signal,
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When the information is recorded by forming a recording mark on the recording layer of the recording medium and recording information, the additional pulse signal is arbitrarily set on and off, and the additional pulse signal has the single pulse width Is a divided additional pulse signal composed of a first divided pulse signal, a central divided pulse signal, and a rear divided pulse signal, and the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces According to the divided additional pulse signal, the first divided pulse signal, the central divided pulse signal, and the rear divided pulse signal. A twelfth step of setting the one-off even without,
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal for subtracting the light output of the light source from the single pulse light by the single pulse signal, and the single pulse width is set. A divided additional pulse signal consisting of a divided first part divided pulse signal, central divided pulse signal, and rear divided pulse signal. According to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, among the leading part divided pulse signal, the central part divided pulse signal, and the rear part divided pulse signal of the divided additional pulse signal A thirteenth step for setting at least one of on and off;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, the additional pulse signal is arbitrarily set to ON / OFF, and the additional pulse signal is a signal for arbitrarily setting at least one of a pulse time width and a pulse generation position, and the single pulse width. Is a divided additional pulse signal consisting of a leading part divided pulse signal, a central part divided pulse signal and a rear part divided pulse signal, Depending on the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces, of the leading part divided pulse signal, the central part divided pulse signal and the rear part divided pulse signal of the divided additional pulse signal A fourteenth step of setting at least one on / off;
The light source emits single pulse light by the single pulse signal and additional pulse light by the additional pulse signal that emits pulse light having a pulse time width different from the single pulse signal, and the emitted single pulse light and additional pulse light are emitted. When recording information by forming a recording mark on the recording layer of the recording medium and recording information, the recording speed of the recording medium, the length of the recording mark, or the length of the space before and after Accordingly, on / off of the additional pulse signal is arbitrarily set, and the additional pulse signal is a subtraction pulse signal that subtracts the light output of the light source from the single pulse light by the single pulse signal, and the pulse time width or pulse generation It is a signal for arbitrarily setting at least one of the positions, and the leading portion obtained by dividing the single pulse width A divided additional pulse signal composed of a pulse signal, a central division pulse signal, and a rear division pulse signal, and the division according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces A fifteenth step of setting on / off of at least one of the leading part divided pulse signal, the central part divided pulse signal, and the rear part divided pulse signal of the additional pulse signal;
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. A sixteenth step for arbitrarily setting ON / OFF of any one of a leading additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal of the signal;
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of a head additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal is set on / off arbitrarily, and the multi additional pulse signal is set. A seventeenth step of a subtraction pulse signal for subtracting the light output of the light source to the multi-pulse signal,
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of a head additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal is set on / off arbitrarily, and the multi additional pulse signal is set. , The prepended pulse signal portions and said central additional pulse signal portion and the rear additional pulse signal portion, and the 18 strokes of a signal for setting arbitrarily at least one of the pulse duration and the pulse generation position,
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal is recorded. At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of a head additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal is set on / off arbitrarily, and the multi additional pulse signal is set. A subtracting pulse signal for subtracting the light output of the light source from the multi-pulse signal, and a pulse time width and a pulse generation position of the leading additional pulse signal portion, the central additional pulse signal portion, and the backward additional pulse signal portion. A nineteenth stroke which is a signal for arbitrarily setting at least one of
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of a head additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal is set on / off arbitrarily, and the multi additional pulse signal is set. , A 20th stroke is a signal to arbitrarily set the light output of the light source,
When recording information on a recording medium by emitting a multi-pulse light from a light source by a multi-pulse signal composed of a head pulse portion, a plurality of central pulse portions, and a rear pulse portion, the head of the multi-pulse signal At least one multi-addition pulse signal composed of a leading additional pulse signal unit, a central additional pulse signal unit, and a rear additional pulse signal unit is added to each of the partial pulse unit, the plurality of central pulse units, and the rear pulse unit. When the information is recorded by forming a recording mark on the recording layer of the recording medium, the multi-addition pulse is selected according to the recording speed of the recording medium, the length of the recording mark, or the length of the front and rear spaces. Any one of a head additional pulse signal portion, a central additional pulse signal, and a rear additional pulse signal is set on / off arbitrarily, and the multi additional pulse signal is set. And a subtracting pulse signal for subtracting the light output of the light source from the multi-pulse signal, and comprising at least two steps of a twenty-first step which is a signal for arbitrarily setting the light output of the light source. An information recording method characterized by the above.   12. A laser drive circuit comprising means for executing the information recording method according to claim 1.   An information recording apparatus comprising the laser drive circuit according to claim 12.

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