JP2008152917A - Method and device for generating formatter drive clock, device for generating the drive clock, method and device for optical disk master exposure, optical disk drive device, optical disk master plate produced by the same, and information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To strictly and accurately obtain a formatter drive clock that realizes a CLV format for CAV driving by calculation, and to form an information track by exposure using the same. <P>SOLUTION: In the optical disk master plate exposure device which exposes by CAV driving, with the controls of a drive motor 8 for rotating a turntable T on which an original glass disk 5 of an optical disk is placed, a rotation drive means of an encoder 7, an exposure optical system 2 for converging and irradiating an optical beam onto an information track, a convergence and irradiation means of a focus actuator 4, an air slider 10 for making the convergence and irradiation means move transversely in a plane parallel to the original glass disk 5, and by a transverse feeding means for a motor driver 11, a rotation drive means, and a transverse drive means, a strict as well as accurate formatter drive clock is obtained through calculation, from the rotational angle speed ω<SB>0</SB>of the turntable, a CLV drive starting radius R<SB>0</SB>; and a track pitch P, a CLV format information track driven by the CAV is formed on the original glass disk 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a formatter driving clock generation method and formatter driving clock according to CLV (Constant Linear Velocity) format formation by CAV (Constant Angular Velocity) driving as an information track by exposure on an optical disc master. The present invention relates to an optical disc master, an optical disc master exposure method, an optical disc master exposure device and an optical disc drive device, and an optical disc master and an information recording medium created thereby.

  In recent years, there has been a growing demand for a large capacity optical disk medium as a large-capacity storage medium for recording high-quality moving images and having a high access speed. In addition, there are several methods for increasing the capacity, such as a method of forming a light beam spot, track pitch, and pit length to be recorded and reproduced using near-field light, a multilayered optical disk medium recording layer, Methods such as multi-level recording information have been proposed and studied.

  In the above-mentioned narrow track pitch, the problem of crosstalk between adjacent tracks is constantly attached. An example of a crosstalk reduction method related to a CLV format disk in which address information and rotation synchronization information are formed by meandering tracks is disclosed in, for example, Patent Document 1. As disclosed herein, as a method to prevent playback wobble signal deterioration due to crosstalk of adjacent track wobbles, the obtained playback is assumed to maintain a specific relationship between the current track wobble and the internal and external adjacent track wobbles. A wobble format has been devised so that the influence of crosstalk does not appear in the signal.

  However, it is not so easy to actually form the wobble format on the optical disc master accurately. When normal “CLV wobble format exposure by CLV drive” is performed, the rotation speed of the turntable on which the optical disc master is placed is moved as the exposure radius position moves from the inner periphery to the outer periphery in order to keep the exposure linear velocity constant. In addition, it is necessary to smoothly change (slow down) the lateral movement speed of an optical moving table equipped with an optical system for irradiating a turntable or an exposure light beam in inverse proportion to the radial position of the optical disk master.

  The turntable has high inertia, and is controlled to follow the ideal rotation speed to achieve CLV drive accuracy that can maintain the effective phase relationship between adjacent tracks for wobbles etc. formed on the information track It was extremely difficult to do (conventional CLV format discs did not require this precision). An exposure method using exposure beam irradiation position correction and concomitant use is also conceivable. However, it is necessary to introduce a high-precision detector for the rotational position, which is expensive, and another problem such as a limitation on the number of rotations occurs, which lacks feasibility.

  Another forming method is “CLV wobble format exposure by CAV driving”. In this case, the turntable rotates at a constant rotation speed, and the rotation accuracy can be obtained extremely high. The rotational position accuracy between adjacent tracks is sufficient to obtain a resolution of a fraction of the wobble length. However, in this case, in order to form the CLV wobble format on the optical disc master that is rotated by CAV driving, the basic operation clock of the format signal generator for generating the wobble format signal is changed according to the radial position of the optical disc master. Therefore, it is necessary to change the wobble cycle length (time axis) generated according to this clock. The wobble cycle length (time axis) is shortened as it goes to the outer periphery. At this time, the physical length of the wobble formed on the master is constant.

  Further, as another example, when driving by the CAV driving method, it is possible to stably rotate the optical disc master in both the CAV preformat and the CLV preformat, and to include a preformat with high pit position accuracy. In order to obtain an optical disc master, an optical disc master exposure method for modulating and demodulating laser light from a laser light source, condensing the modulated light with an objective lens and irradiating the optical disc master with pits on the surface of the master, is disclosed in Patent Literature Second, the optical disk master is rotated by the CAV driving method, and the laser light applied to the optical disk master is modulated and controlled using the laser light modulation means driven and controlled by the modulation signal generating means. CLV preformer on optical disc master rotated by CAV drive system with light It has been described to form the door.

  Further, in order to perform processing of a stamper with high recording signal accuracy by changing the processing speed with a simple configuration, Patent Document 3 discloses a mastering signal stored in advance in a signal storage device at the time of stamper creation by a CPU. The modulation means repeatedly outputs the signal in the buffer to the signal correction means continuously at a constant signal transfer rate after modulation, and the signal is then corrected and continuously output. It is described that the cutting machine performs stamper processing in real time based on the above.

  In addition, in order to form an information pit sequence with a constant physical data length on the glass master by stable control by CAV driving, the laser light emitted from the laser light source is modulated by the laser modulator and irradiated to the glass master. In order to record the information pit row on the glass master by rotating the glass master with a turntable and a rotary motor and laterally moving with a lateral feed table and a feed motor, Patent Document 4 discloses that a modulation signal control unit is rotated. A signal and a feed position signal are input, a clock to be applied to the modulation signal generator is generated based on a command from the MPU, and the glass master is CAV-driven by setting the first and second frequency dividers. The above describes that information pits having a constant physical data length are recorded.

  In the optical recording apparatus, in the CLV control, the rotational speed of the recording disk and the feed speed of the optical recording system are varied by detecting the radial position of the disk at the time of signal recording. In order to improve the recording accuracy as a speed, the reference clock of the EFM modulation signal for modulating the recording laser beam is set to a frequency lower than the reference clock at the inner periphery of the disk and higher than the reference clock at the outer periphery of the disk. Focusing on the fact that the length of the pit length in the outer circumferential direction of the disk changes, it is disclosed in Patent Document 5 that the system configuration brings about the same effect as recording with the rotational speed and feed speed of the disk varied. Is described.

  Specifically, as shown in FIG. 18, the driving clock supplied to the encoder 103 is obtained by calculating the position information of successive exposure radius positions by inputting the position information to the arithmetic circuit 101 and passing through the PLL circuit 102. Yes. The fixed reference by CLV control is obtained by driving the rotation system of the glass master and the optical feed system of the condensing optical mechanism at a constant speed and making the clock of the encoder 103 for changing the recording signal into a variable clock signal proportional to the recording position. The same effect as recording with a clock-encoded EFM modulated signal is obtained.

Furthermore, in an optical disc master exposure apparatus, a CLV drive control method by generating a high-precision CLV drive command pulse with an ideal and small local deviation of a spindle and a linear motor, and a cumulative error accompanying a calculation error for each track The CLV disc format enables the generation of highly precise CLV drive command pulses that are closer to the ideal without generating any errors, and the circumferential arrangement and track number of each access unit on the disc is the ideal CLV disc format. In order to provide a recording medium, the optical disk master exposure apparatus divides the number of pulse trains of the basic clock in proportion to the ideal track length determined by the spiral start radius position, the number of tracks, and the spiral track pitch every rotation of the spindle. Spindle rotation command pulse train and Controlling the driving of the spindle motor and the slider is described in Patent Document 6 by Ida movement command pulse train.
JP 2000-163809 A JP-A-5-234152 JP-A-6-89468 JP-A-8-203133 JP-A-9-17115 JP 2001-143376 A

  As for the above-mentioned “CLV format exposure by CAV driving”, several methods have been proposed as described in the prior art. However, in these proposed methods, for example, in the description of Patent Document 2, as a specific implementation method, a clock is generated using the radial position information and via the voltage controlled oscillator. Accuracy and analog uncertainty are included, and sufficient accuracy cannot be guaranteed. In Patent Document 3, correction is performed using the value of the data length per unit time as described in paragraphs [0033] to [0038]. In the clock generation of Patent Document 3, Since it is generated via a voltage controlled oscillator, analog uncertainty is included and sufficient accuracy cannot be guaranteed.

  Furthermore, the clock generation in Patent Document 4 describes that the formatter driving clock is generated by using a reference clock that changes in proportion to the integrated value of the rotational speed of the turntable, the radial position, the CAV driving time, or the linear velocity. However, all of them acquire such information and generate a clock based on the information, and the specific configuration is a circuit configuration via a voltage-controlled oscillator, which is an analog failure. Definiteness is included and sufficient accuracy cannot be guaranteed. Especially, when using location information, the clock obtained depends on the accuracy, so there is a time delay due to location information feedback. .

  As described above, in any of the conventional examples described above, there is a problem that the method / configuration for forming a strictly accurate CLV format is insufficient.

The present invention is directed to solving the above-described problems of the prior art, and is not a conventional method of generating a clock by sequentially using radial position information during CAV driving, but a rotational angular velocity ω ₀ , CLV of a turntable By calculating the drive start radius R ₀ and the track pitch P, the formatter drive clock generation time for realizing the CLV format is strictly and accurately obtained as the formatter drive clock, and an information track is formed by exposure using this formatter. Formatter drive clock generation method, formatter drive clock generation device, drive clock generation device, optical disc master exposure method, optical disc master exposure device and optical disc drive device, and optical disc master and information produced thereby Provide recording media An object of the present invention is to.

  In order to achieve this object, a formatter drive clock generation method according to claim 1 is used in an optical disk master exposure apparatus to form an information pitch spiral-shaped information track having a CLV format on a CAV-driven optical disk master. Formatter drive clock generation method using the track generation time obtained from the track pitch, the rotational angular frequency of the CAV-driven optical disc master, the basic segment length of the information track in the CLV format, and the CLV drive start radius position. By this method, a formatter drive clock that enables CLV format exposure in a CAV drive state is obtained by rigorous calculation without using radial position information and without including an analog configuration. Generating a formatter drive clock It can be.

  The formatter drive clock generation method according to claim 2 or 3 is the formatter drive clock generation method according to claim 1, wherein an arbitrary clock including a plurality of clocks generated using the clock generation time is between clocks. Generate by using the average time interval obtained by dividing by the number of included clocks, and average so that the clock position calculated to obtain the average time interval is less than the resolution of the pulse generation position This method is characterized in that the number of target clocks is set. By this method, a formatter drive clock is generated by a simpler operation, and the time error for averaging is set within a range equal to or lower than the time setting resolution. The generation time can obtain the same result as when averaging is not performed.

  The formatter drive clock generation method according to claim 4 is a formatter drive clock generation method for forming an information track having an equal pitch spiral shape having a CLV format on an optical disk master disk driven by CAV in an optical disk master disk exposure apparatus. Generated using the clock pitch generated by the clock generation time obtained from the track pitch, the rotation angular frequency of the CAV-driven optical disc master, the basic line length of the information track in the CLV format, and the CLV drive start radius position By this method, the formatter driving clock that enables CLV format exposure in the CAV driving state is not subjected to the radial position information and does not include an analog configuration, and the formatter is driven by strict calculation. Generate drive clock It is possible.

  The formatter drive clock generation method according to claim 5 or 6 is the formatter drive clock generation method according to claim 4, wherein the formatter drive clock generation method includes a plurality of clocks generated by using the clock generation time, and is between the clocks. The number of clocks to be averaged is set so that the clock cycle calculated to obtain the average clock cycle is less than or equal to the resolution of the pulse generation cycle. By this method, the formatter drive clock is generated by simpler calculation, and the time error for averaging is set within the resolution of the period setting, and the clock generation period is averaged. You can get the same results as if you did not.

  The formatter drive clock generation method according to claim 7 is a formatter drive clock generation method for forming an information track of an equal pitch spiral shape having a CLV format on an optical disk master disk driven by CAV in an optical disk master disk exposure apparatus. Then, using the track pitch, the rotational angular frequency of the CAV-driven optical disc master, the basic line segment length of the information track in the CLV format, and the period difference of the clock train generated from the clock generation time obtained from the CLV drive start radius position By this method, a formatter drive clock that enables CLV format exposure in a CAV drive state is obtained by rigorous calculation without using radial position information and without including an analog configuration. Formatter drive clock generation It can be.

  The formatter drive clock generation method according to claim 8 or 9 is the formatter drive clock generation method according to claim 7, wherein an arbitrary clock including a plurality of clocks generated using the clock generation time is between clocks. Generated using the average difference value of the period differences of the included clock trains, and averaged so that the clock period difference calculated to obtain the average clock period difference value is below the resolution of the pulse generation period This method is characterized in that the number of target clocks is set, and this method is used to generate a formatter drive clock by simpler calculation and to set the time error for averaging within the resolution of the period difference setting. The clock generation period difference can obtain the same result as when the averaging is not performed.

  The formatter drive clock generation method according to claim 10 is the formatter drive clock generation method according to claim 2, 5 or 8, wherein an interval for performing approximation between clocks is tracked between arbitrary clocks including a plurality of clocks. In this method, the phase relationship between adjacent tracks of various types of information mounted on the information track can be made to coincide with an accurate time position for each track.

  The formatter drive clock generation method according to claim 11 is a formatter drive clock generation method for forming an information track having an equal pitch spiral shape having a CLV format on an optical disk master disk driven by CAV in an optical disk master disk exposure apparatus. The number of formatter drive clocks included in the rotation angle is increased by a certain integer for each arbitrary rotation angle of the CLV format composed of the information tracks having the equal pitch spiral formed. In the CLV format formation, the value of the period fraction accumulation register or the period difference fraction accumulation register is initialized for each formatter drive clock corresponding to an arbitrary rotation angle. By this method, the time for averaging is set. Within a range where the error is less than the resolution of the period difference setting Clock generating period difference is constant can be obtained results the same as case without averaging.

  A formatter drive clock generation device according to claim 12 is a formatter drive clock generation device for forming an equi-pitch spiral information track having a CLV format on a CAV-driven optical disc master in an optical disc master exposure apparatus. Based on the values obtained by the detecting means for obtaining the values of the track pitch, the rotational angular frequency of the master disc of the optical disk driven by CAV, the basic line segment length of the information track in the CLV format, and the CLV driving start radius position, Computation means for obtaining a clock generation time, and count means for generating a formatter drive clock in accordance with the output of the computation means, and a formatter capable of CLV format exposure in a CAV drive state by this apparatus Can create a driving clock Kill.

  The formatter drive clock generator according to claims 13 and 14 is the formatter drive clock generator according to claim 12, wherein the formatter drive clock generator includes a plurality of clocks including a plurality of clocks generated using clock generation times of the arithmetic means. An average calculating means for obtaining an average time interval obtained by dividing by the number of clocks included between the clocks, generating a formatter drive clock by the counting means according to the output of the average calculating means, and further calculating the average calculating means Is provided with setting means for setting the number of clocks to be averaged so that the clock position calculated in step 1 is equal to or less than the resolution of the pulse generation position. By this apparatus, the formatter drive clock by simpler calculation is provided. And the averaging time error is set within the time setting resolution. Clock generation time Te can obtain the same result as the case without averaging.

  The formatter drive clock generating device according to claim 15 is a formatter drive clock generating device for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master in an optical disc master exposure apparatus. Based on the values obtained by the detecting means for obtaining the values of the track pitch, the rotational angular frequency of the master disc of the optical disk driven by CAV, the basic line segment length of the information track in the CLV format, and the CLV driving start radius position, An arithmetic means for obtaining a cycle of a clock train generated according to a clock generation time and a count means for generating a formatter driving clock in accordance with an output of the arithmetic means are provided. Formatter that enables exposure It is possible to create a dynamic clock.

  The formatter drive clock generation device according to claim 16 or 17, in the formatter drive clock generation device according to claim 15, between any clocks including a plurality of clocks generated using the clock generation time of the arithmetic means. An average calculating means for obtaining an average clock period of a clock train included between clocks, generating a formatter drive clock by a counting means according to an output of the average calculating means, and further calculating an average clock period calculated by the average calculating means Is provided with setting means for setting the number of clocks to be averaged so as to be equal to or less than the resolution of the pulse generation period, and by this apparatus, a formatter driving clock is generated by a simpler operation, Also, the averaging time error is set within the range of the resolution of the cycle setting. Is the clock generation period can be obtained the same result as the case without averaging.

  The formatter drive clock generation device according to claim 18 is a formatter drive clock generation device for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master in an optical disc master exposure apparatus. Based on the values obtained by the detecting means for obtaining the values of the track pitch, the rotational angular frequency of the master disc of the optical disk driven by CAV, the basic line segment length of the information track in the CLV format, and the CLV driving start radius position, Comprising arithmetic means for obtaining a period difference of a clock train generated according to clock generation time, and count means for generating a formatter drive clock in accordance with the output of the arithmetic means. Four that enables CLV format exposure It is possible to create a jitter driving clock.

  The formatter drive clock generator according to claims 19 and 20 is the formatter drive clock generator according to claim 18, wherein the formatter drive clock generator includes a plurality of clocks generated using the clock generation times of the arithmetic means. An average calculation unit that obtains an average difference value of the period differences of the clock trains included between the clocks, generates a formatter drive clock by the counting unit according to the output of the average calculation unit, and is further calculated by the average calculation unit It is characterized by setting means that sets the number of clocks to be averaged so that the clock cycle difference is less than or equal to the resolution of the pulse generation cycle. This device generates formatter drive clocks by simpler calculations. And the averaging time error is less than the resolution of the period difference setting. Clock generating period difference is set to enclose can obtain the same result as the case without averaging.

  The formatter drive clock generation device according to claim 21 is the formatter drive clock generation device according to claim 13, 16 or 19, wherein the average calculation means approximates the clocks between arbitrary clocks including a plurality of clocks. The interval to be performed is performed for each track or in a unit smaller than the track. With this apparatus, the phase relationship between adjacent tracks can be matched to an accurate time position for each track.

  A formatter drive clock generation device according to claim 22 is a formatter drive clock generation device for forming an equi-pitch spiral information track having a CLV format on a CAV-driven optical disc master in an optical disc master exposure apparatus. The number of formatter drive clocks included in the rotation angle is increased by a certain integer for each arbitrary rotation angle of the CLV format composed of the information tracks having the equal pitch spiral formed. In the CLV format formation, there is provided means for initializing the value of the period fraction accumulation register or the period difference fraction accumulation register for each formatter drive clock corresponding to an arbitrary rotation angle. Error is less than the resolution of the period difference setting Clock generating period difference is set to a range of the results can be obtained in the same as the case without averaging.

  A drive clock generator according to claim 23 is provided on the formatter drive clock generator according to any one of claims 12 to 22, a turntable on which an optical disk master is mounted and rotated by a rotation driving means, and an optical disk master Based on the information recording signal to form an information track, a converging irradiation means for the recording light beam, a transverse feed driving means for moving either the turntable or the converging irradiation means in a direction parallel to the optical disk master plane, and rotational driving And a drive control means for controlling the transverse feed drive means, wherein the drive control means forms an information track of various formats on the optical disk master by means of the drive control means. Same for drive clock, lateral feed drive clock and formatter drive clock And a clock switching means for a formatter drive clock used for CLV format formation in the CLV drive state and CLV format formation in the CAV drive state, and a CLV format formation by the CLV drive, or CLV format formation by CAV driving can also be supported, and the CAV or CLV driving method can be switched depending on the formation area during formation of the information track.

  An optical disk master exposure method according to claim 24 is an optical disk master exposure method according to claim 23, a turntable on which the optical disk master is placed and rotated by rotation driving means, and information recording for forming an information track on the optical disk master. Based on the signal, it controls the convergent irradiation means of the recording light beam, the transverse feed drive means for moving either the turntable or the convergent illumination means in a direction parallel to the optical disc master plane, the rotational drive means, and the transverse feed drive means. An optical disc master exposure method comprising: forming an information track of various formats on an optical disc master by controlling the rotational drive means and the lateral feed drive means of the drive control means by an optical disc master exposure apparatus having a drive control means for CLV format exposure in CLV driving state and CLV driving state in CAV driving state The CLV format exposure is performed by switching the mat exposure, and this method can cope with CLV format exposure by CLV driving or CLV format exposure by CAV driving, and during exposure of an information track comprising the CLV format. In addition, it is possible to perform exposure by switching the driving method of CAV or CLV depending on the exposure region.

  An optical disk master exposure apparatus according to claim 25 is a drive clock generation device according to claim 23, a turntable on which the optical disk master is mounted and rotated by rotation driving means, and an information recording for forming an information track on the optical disk master. Based on the signal, it controls the convergent irradiation means of the recording light beam, the transverse feed drive means for moving either the turntable or the convergent illumination means in a direction parallel to the optical disc master plane, the rotational drive means, and the transverse feed drive means. An optical disk master exposure apparatus for forming information tracks of various formats on the optical disk master by the drive control means, for CLV drive exposure in CLV drive state and CLV drive exposure in CAV drive state Provide exposure switching means to perform CLV format exposure And symptoms, by the device, to enable the CLV format exposure by CLV driving or CAV drive, during the exposure of the information track, it is exposed switching the driving method of the CAV or CLV by exposure regions.

  An optical disk drive device according to a twenty-sixth aspect is the drive clock generating device according to the twenty-third aspect, a turntable on which an optical disk medium is placed and rotated by a rotation driving means, and an information recording signal for forming an information bit string on the optical disk medium Based on the control, the recording light beam convergent irradiating means, the transverse feed driving means for moving either the turntable or the convergent irradiating means in a direction parallel to the optical disk medium plane, the rotational driving means, and the laterally feeding drive means are controlled. An optical disk drive apparatus for forming an information track of an information pit string of various formats on an optical disk medium by the drive control means, wherein the CLV format writing in the CLV drive state and the CLV format in the CAV drive state CLV format writing provided with writing switching means In accordance with both the CLV format exposure by CLV driving and the CLV format exposure by CAV driving, the driving method is changed depending on the writing area during the formation of information pits formed in the CLV format. Switching writing can be performed.

  An optical disk master according to claim 27 is characterized in that an information track having an equal pitch spiral shape having a CLV format is formed in a CAV drive state by using the optical disk master exposure apparatus according to claim 25. It is possible to create an information recording medium in which the phase relationship between adjacent tracks of various types of information formed on the information track is equivalent to the phase relationship between adjacent tracks in the CLV format.

  An information recording medium according to a twenty-eighth aspect is characterized in that the information recording medium is produced by the optical disk master according to the twenty-seventh aspect and has an information track having an equal pitch spiral shape having a CLV format on the CAV-driven optical disk master. Depending on the recording medium, crosstalk between adjacent tracks due to various information formed on the information track can be reduced.

  As described above, according to the present invention, the formatter drive clock is accurately generated by the operation using the clock generation time, the clock period, the period difference, and the average value thereof, and the optical disc master exposure apparatus using the same And an optical disc master which suppresses crosstalk due to various information on the information track by forming an exposure in CLV format by switchable CLV drive and CAV drive, and forming an information track having an accurate phase relationship between adjacent tracks There is an effect that an information recording medium can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a basic configuration of an optical disc master exposure apparatus according to an embodiment of the present invention. In FIG. 1, 1 is an exposure laser for exposing a glass master 5 coated with a photoresist, 2 is an exposure optical system that shapes a light beam emitted from the exposure laser 1 and guides the light beam to a focus actuator 4, 3 is a light amount modulator for changing the intensity of the light beam irradiated on the glass master 5, and 6 is a signal Fout from the format signal generator 16 for generating signals for forming pre-embossed pits and grooves on the glass master 5. An optical modulator for turning on and off the light beam of the exposure laser 1, 7 an encoder which is attached to the drive motor 8 of the turntable T and outputs a pulse train according to the rotation, and 9 is for detecting the radial position of the exposure spot It is a linear encoder.

  The glass master 5 is attracted to the turntable T and rotated by the drive motor 8. At the same time, the focus actuator 4 is moved in the radial direction of the glass master 5 by the air slider motor 10. Then, the incident light beam is focused on a very small spot, and focus control is constantly performed so that the beam waist position is kept at the photoresist position (an optical system for focus control is not shown).

  Further, 11 is a slider motor driver for driving the air slider motor 10, 12 is a drive motor driver for driving the drive motor 8, and 13 and 14 are for movement and rotation commands instructed by the controller 15. A control circuit 17 for smoothly and accurately following the slider and the turntable, 17 is a lateral feed for driving the slider and the drive motor drivers 11 and 12, and a lateral feed for generating a drive clock in the rotational drive control circuits 13 and 14. This is a basic clock generator that supplies a basic clock to the rotation drive clock generation circuits 18 and 19 and the formatter drive clock generation circuit 20 that generates a drive clock for driving the format signal generator 16. Here, a sensor for detecting an absolute position for presetting a linear scale value is omitted. Further, the optical disk master exposure apparatus needs to be set in accordance with various disk formats, such as 2-beam exposure, exposure beam meandering, etc., but various exposure optical systems required for these are omitted because they are not directly related to the present invention. A portion surrounded by a broken line in FIG. 1 corresponds to a drive clock generation unit.

  Next, Example 1 according to Embodiment 1 of the present invention will be described below with reference to FIG. As shown in FIG. 1, a turntable T on which an optical disk glass master 5 is mounted, a rotational drive means comprising a drive motor 8 and an encoder 7 for rotating the same, and an information track as an information track based on an information recording signal. Convergent exposure means such as an exposure optical system 2 for focusing and irradiating a light beam, a focus actuator 4 and the like, and a turntable T on which the glass master 5 is mounted are moved laterally in a plane parallel to the glass master 5, and a lateral feed drive for lateral feed drive Means (not shown) or the above-mentioned recording light beam convergent irradiating means is moved laterally within a plane parallel to the glass master 5, and a lateral feed for lateral feed driving such as an air slider motor 10 and a slider motor driver 11 is carried out. An optical disc provided with a driving means and exposed by CAV (constant angular velocity) driving under the control of the rotational driving means and the lateral feed driving means In board exposure device, to form a data track of constant pitch spiral by CLV driving on a glass master 5 of the optical disc.

  Now, in an information track having an equal pitch spiral formed by CLV driving, the total information track length L at time t from the start of CLV driving is as shown in (Equation 1), (Equation 2), and (Equation 3). I want.

ここで、ターンテーブルＴの回転角速度をω_０、ＣＬＶ駆動開始半径をＲ_０、トラックピッチをＰとする。

Here, the rotational angular velocity of the turntable T is ω ₀ , the CLV drive start radius is R ₀ , and the track pitch is P.

  Substituting (Equation 2) into (Equation 1),

これにより、ＣＬＶ駆動開始から時間ｔを求めると、（数４）のようになる。

Thus, when the time t is obtained from the start of CLV driving, (Equation 4) is obtained.

（数４）は、ＣＡＶ駆動による等ピッチスパイラル状の情報トラックを形成する際の、形成開始からの形成情報トラック長がＬのときの形成開始からの経過時間を表している。

(Equation 4) represents an elapsed time from the start of formation when the formation information track length from the start of formation is L when forming an equal-pitch spiral information track by CAV driving.

  In the CLV format, the length corresponding to 1 cb (channel bit) forming the basis of the format is constant everywhere on the information track. Therefore, if the length equivalent to 1 cb is Lcb, (Equation 5)

（数５）を（数４）へ代入し、（数６）となる。

Substituting (Equation 5) into (Equation 4) gives (Equation 6).

ｔ_n はＬcb相当長進む毎の経過時間を示すことになる。

t _n indicates an elapsed time every time the length corresponding to Lcb is advanced.

Therefore, by operating the clock train generated every t _n as formatter driving clock, it is possible to form the information track of CLV format on the glass master disk 5 that is CAV drive. FIG. 2 schematically shows how the elapsed time t _n changes when the horizontal axis is Lcb × n and the vertical axis is t _n .

Further, as a second embodiment of the first embodiment, the position of the generated clock among the m Lcb considerable length of the information track, the time interval between the leading end time of the information track t _a and the rear end time t _{a + m} Using the average time interval t _AVE , which is a value obtained by dividing by m, (Equation 7)

ｔ_a とｔ_a+m 間の各チャンネルビット位置に対応した近似クロックを生成し、これをフォーマッタ駆動クロックとする。時間ｔ_a〜ｔ_a+m 間のクロック生成の時間ｔi をｉの１次式から求めることができ演算が容易となる。図３には横軸にＬcb×ｎ、縦軸にｔ_n としたときの近似ｔ_n を模式的に示す。

An approximate clock corresponding to each channel bit position between t _a and t _{a + m} is generated and used as a formatter drive clock. The clock generation time t i between the times t _{a and} t _{a + m} can be obtained from the linear expression of i, and the calculation becomes easy. FIG. 3 schematically shows an approximate t _n where Lcb × n is on the horizontal axis and t _n is on the vertical axis.

  FIG. 4 is a block diagram showing a schematic configuration of the formatter drive clock generation circuit according to the first embodiment, which will be described with reference to the counter circuit 21 that counts the basic clock and the first or second embodiment of the first embodiment. A register circuit 22 that holds a position count designation value corresponding to the clock generation position obtained by the above method, and a count value coincidence detection circuit 23 that detects coincidence between the count value of the counter circuit 21 and the value set in the register circuit 22; And an arithmetic circuit or an arithmetic unit that sequentially generates clock generation position data (not shown).

  Further, in FIG. 5, a delay circuit 24 having a plurality of taps for continuously delaying the basic clock at a certain time interval equal to or shorter than the basic clock period is added as in FIG. As shown in FIG. 6, by specifying the count value of the basic clock and the state of each delay pulse, it is possible to specify the formatter drive clock (FClk) generation position with a resolution lower than the basic clock.

  The count length of the counter circuit 21 shown in FIGS. 4 and 5 does not need to be configured so that the entire time for generating the formatter drive clock can be counted, but is configured with a count length equal to or greater than the maximum length of the generated clock cycle. If so, continuous clock generation positions can be specified.

  The position count designation value (data corresponding to the clock generation position) is constantly obtained by an arithmetic circuit or an arithmetic device, and is obtained by an ideal clock generation position (formula 7) for forming the CLV format in the CAV drive state. ) Is given as a value. The position count designation value may be obtained sequentially by an arithmetic circuit or an arithmetic unit. However, when the arithmetic time becomes a problem, a method such as obtaining all data in advance and storing it in ROM or RAM is taken. . Alternatively, a method of storing all data in an external storage device such as a hard disk and sequentially transferring the data to the RAM on the formatter drive clock generation circuit may be used.

  Further, by limiting the target clock area to be averaged in the formatter drive clock generation, the error with respect to the true clock generation time is kept below the time setting resolution.

  In an ideal formatter drive clock, when the horizontal axis is time (corresponding to the information track length because the linear velocity is constant in CLV), the time, period, and period difference change nonlinearly. Therefore, the error between the formatter drive clock position obtained from the average value and the ideal position varies depending on how to obtain the average in the time domain. Therefore, the target area to be averaged is determined so that the error becomes smaller than the resolution (basic clock period) of the set time.

  Since the time error for performing the averaging is set within a range that is equal to or less than the time setting resolution, the obtained clock generation time can obtain the same result as that when the averaging is not performed.

Next, a first embodiment of the second embodiment of the present invention, from equation (7) of the first embodiment, when determining the time interval, i.e. the clock period T _n between t _n clock and t _n-1 clock (several 8).

（数８）を用いて、ＣＡＶ駆動状態でのＣＬＶフォーマットを形成するためのフォーマッタ駆動クロックの生成を行うことができる。

(Formula 8) can be used to generate a formatter drive clock for forming a CLV format in the CAV drive state.

Since this (Equation 8) gives a period, the formatter drive clock generation circuit can be configured by a general frequency dividing circuit using a counter circuit or the like. FIG. 7 schematically shows how the clock cycle T _n changes when the horizontal axis is Lcb × n and the vertical axis is T _n .

Further, as a second embodiment of the present embodiment 2, m pieces of the position of the clock generation between corresponding length of the information track Lcb, the tip position of the information track clock period T _a and the rear end position of the clock period T _{a Using} the average clock period T _AVE of clocks included between _{+ m} , (Equation 9)

クロック周期Ｔ_a とクロック周期Ｔ_a+m間の各チャンネルビット位置に対応した近似クロックを生成し、これをフォーマッタ駆動クロックとする。これにより、周期情報に基づいたクロック生成を行うことができ、カウンタ回路を用いた簡単な分周回路によってフォーマッタ駆動クロック生成回路を構成することができる。図８には横軸をＬcb×ｎ、縦軸をＴ_nとしたときの、近似クロック周期Ｔn を模式的に示す。

An approximate clock corresponding to each channel bit position between the clock cycle T _a and the clock cycle T _{a + m} is generated and used as a formatter drive clock. Accordingly, clock generation based on the period information can be performed, and the formatter drive clock generation circuit can be configured by a simple frequency dividing circuit using a counter circuit. When the horizontal axis Lcb × n, the vertical axis was T _n in Figure 8, it shows the approximate clock cycle Tn schematically.

  FIG. 9 is a block diagram showing a schematic configuration of the formatter drive clock generation circuit according to the second embodiment. In FIG. 9, period data (real value) of the formatter drive clock (Fclk) to be generated is given to the period data processing circuit 25 from an arithmetic circuit or arithmetic unit (not shown). The cycle data processing circuit divides the cycle data into an integer part and a decimal part, and sets them in the cycle generation circuit 26 and the cycle fraction accumulation register 27, respectively. The cycle generation circuit 26 outputs a pulse after a specified number of times corresponding to the basic clock according to the cycle generation data (integer part). The cycle generation data (fractional part) is temporarily stored in the cycle fraction accumulation register 27, added to the cycle data (real value) for generating the next formatter drive clock (Fclk), and the data processing for cycle generation is performed again. Applied.

  Here, the periodic data is updated for each pulse when it is generated for each pulse, and for each average section when it is generated with an average value. The cycle generation circuit 26 is configured by using a basic clock frequency dividing circuit or a parallel / serial conversion circuit using a shift register.

  Periodic data includes computations to find the pi and square root, and no matter how many significant digits are added, the results must contain errors (as long as computation is performed using a finite digit computing device) Value cannot be obtained, including errors). Therefore, in such a situation, it is possible that the cumulative value of the fraction, which should originally be 0, does not become 0. The period fraction accumulation register, which should originally be 0, is forcibly set to 0 so that the error is not propagated to subsequent operations.

  Further, the number of formatter drive clocks in the exposure time of one optical disc master exposure apparatus is enormous, and it is sufficient so that the accumulated error does not exceed the resolution of the period setting (the basic clock period in FIG. 9). Period data is calculated by securing significant digits, and the period data processing circuit 25 and the period fraction accumulation register 27 are configured to realize processing that secures sufficient significant digits.

  For example, in the CLV format including information tracks formed by an equal pitch spiral, the information track length for each arbitrary rotation angle (θ radians) from the spiral center along the information track is θ2 × (track pitch) / ( 2π) It extends in length (when the information track is traced from the inner circumference to the outer circumference). In the case of 2π (one track round), the length is 2π (track pitch). For example, θ = 2π, and an integral part of the increment “2π (track pitch) length” of the information track length for each track is one cycle length of the formatter drive clock (the linear speed is constant, so the time and the line segment on the information track) If the length is set equal to the same), the formatter drive clock position is accurately determined for each track without error.

  In an equal pitch spiral track formed by CLV driving, the total track length L is expressed by (Equation 10), and the spiral radius position r for measuring the total track length L is expressed by (Equation 11).

Ｒ_０はスパイラルの開始半径位置、ｒはトラック長を測定しようとしているスパイラル半径位置、Ｐはスパイラルトラックピッチ、ｎはトラック数を表す。
（数１０），（数１１）から（数１２）が導かれ、

R ₀ is the starting radius position of the spiral, r is the spiral radius position where the track length is to be measured, P is the spiral track pitch, and n is the number of tracks.
(Equation 12) is derived from (Equation 10) and (Equation 11),

また、（数１２）から各トラックのトラック長Ｌnは、（数１３）のように表される。

From (Equation 12), the track length Ln of each track is expressed as (Equation 13).

（数１３）から、隣接トラック間のトラック長差は、以下の（数１４）に示すように一定であることがわかる。

From (Equation 13), it can be seen that the track length difference between adjacent tracks is constant as shown in (Equation 14) below.

また、（数１１）は、求めようとするスパイラル軌跡を、トラックを単位として、すなわち、スパイラルの中心から線路に沿って軌跡の回転角が２πを１単位として表現している。その結果、トラック毎に、２πＰずつトラックのトラック長が増加していくという結果を得た。

(Expression 11) expresses the spiral locus to be obtained in units of tracks, that is, the rotation angle of the locus along the track from the center of the spiral is 2π. As a result, the track length of the track increased by 2πP for each track.

  Assuming that an arbitrary angle θc is one unit instead of 2π, (Equation 11) is as shown in the following (Equation 15) (where the angle θc may be smaller or larger than 2π. The line segment of the spiral line cut out by the angle θc is called a segment).

ｓはセグメント数を表す。（数１０）と（数１５）から、全トラック長Ｌは（数１６）、各セグメントのトラック長Ｌsは（数１７）となり、

s represents the number of segments. From (Equation 10) and (Equation 15), the total track length L is (Equation 16), and the track length Ls of each segment is (Equation 17).

（数１７）から、隣接セグメントのトラック長差は、以下の（数１８）に示すように一定であることがわかる。

From (Equation 17), it can be seen that the track length difference between adjacent segments is constant as shown in (Equation 18) below.

前述したように周期データには、すでに誤差が含まれている（元々、πを含んだ演算であること、平方根を求める等の演算は有限の有効桁の演算装置によって求められることから）ので、本来、真に０にならなければならないはずが完全に０の値とならない（周期端数累積レジスタ）ことになる。図９に記載の周期端数累積レジスタにリセット入力信号を付加し、同一の初期設定（プリセット）値をトラック毎に強制的にセットする。これにより演算によって生成する誤差を解消し誤差の伝播を防ぐ。

As described above, since the period data already contains an error (because it is an operation that originally includes π, and operations such as obtaining the square root are obtained by a finite significant digit arithmetic device), Originally, the value must be truly zero, but it is not completely zero (period fraction accumulation register). A reset input signal is added to the periodic fraction accumulation register shown in FIG. 9, and the same initial setting (preset) value is forcibly set for each track. This eliminates the error generated by the calculation and prevents the propagation of the error.

  As a result, the averaging time is set in a range in which the error is equal to or less than the resolution of the period difference setting, so that the obtained clock generation period difference can obtain the same result as when the averaging is not performed.

Next, as Example 1 of Embodiment 3 of the present invention, when the clock cycle difference ΔT _n between the clock cycle T _n and the clock cycle T _n−1 is obtained from (Equation 8) of Embodiment 2, (Several 19).

この（数１９）を用いて、クロック周期Ｔ_n を表すと（数２０）のようになる。

Using this (Equation 19), the clock cycle T _n is expressed as (Equation 20).

ここで、Ｔ_０ は、ＣＬＶフォーマットの情報トラックを形成開始時における最初のクロック周期である。図１０には横軸をＬcb×ｎ、縦軸をＴ_n としたときの、クロック周期差ΔＴ_n の変化の様子を模式的に示す。

Here, T ₀ is the first clock cycle at the start of forming the information track in the CLV format. FIG. 10 schematically shows how the clock cycle difference ΔT _n changes when the horizontal axis is Lcb × n and the vertical axis is T _n .

Further, as Example 2 of the third embodiment, the position of clock generation between information tracks corresponding to m channel bits in length, the difference between the first clock periods of the information tracks as ΔT _a , and the m-th clock. The difference between the periods is ΔT _{a + m,} and the average difference value ΔT _AVE of the difference between the clock periods is expressed as (Equation 21),

クロック周期Ｔ_a とクロック周期Ｔ_a+m 間の各チャンネルビット位置に対応した近似クロックを生成し、これをフォーマッタ駆動クロックとする。

An approximate clock corresponding to each channel bit position between the clock cycle T _a and the clock cycle T _{a + m} is generated and used as a formatter drive clock.

The generated clock period T _{n + k} between the clock periods T _{a to} T _{a + m} can be obtained from the linear expression of k, and the calculation becomes easy. Further, the accuracy can be improved as compared with the approximation method in Example 2 of Embodiment 2. FIG. 11 schematically shows the approximate clock cycle T _n when the horizontal axis is Lcb × n and the vertical axis is T _n .

  FIG. 12 is a block diagram showing a schematic configuration of the formatter drive clock generation circuit according to the third embodiment. In FIG. 12, the basic period data (integer part) and basic period data (decimal part) of the formatter drive clock (Fclk) to be generated and the period difference data (real number) from the arithmetic circuit or arithmetic unit (not shown) are the period difference data. It is given to the processing circuit 28. The period difference data processing circuit 28 adds the period basic data (decimal part) and the period difference data (real value), divides it into an integer part and a fraction part, and sets them in the period data generation circuit 29 and the period difference fraction accumulation register 30, respectively. To do.

  Further, the period data generation circuit 29 generates and outputs period generation data (integer part) from the period basic data (integer part) and the period difference generation data (integer part), and the period generation circuit 26 generates the period generation data (integer part). ) To output a pulse after a specified number of times corresponding to the basic clock. The period difference generation data (decimal part) is temporarily stored in the period difference fraction accumulation register 30, and the period difference data (real value) for generating the next formatter drive clock (Fclk) and the period basic data (decimal part) are stored. ) And data processing for cycle generation is performed again.

  Here, the basic period data (integer part, decimal part) is fixed, and the period difference data (real number) is a period for each pulse when generated for each pulse, and for each average section when generated with an average value. The difference data is updated. The cycle generation circuit 26 is configured by using a basic clock frequency dividing circuit or a parallel / serial conversion circuit using a shift register.

  Periodic difference data includes computations to find the pi and square root, and the results must contain errors (a true value cannot be obtained as long as computation is performed using a finite digit computing device). , Including errors). Therefore, in such a situation, it is possible that the cumulative value of the fraction, which should originally be 0, does not become 0. Here, the period difference fraction accumulation register, which should be 0, is forcibly set to 0 so that the error is not propagated to subsequent operations.

  Further, the number of formatter drive clocks in the exposure time of one optical disk master exposure apparatus is enormous, and it is sufficient that the accumulated error does not exceed the resolution of the period setting (basic clock period in FIG. 12). Period difference data is calculated by securing significant digits, and the period difference data processing circuit 28, the period data generation circuit 29, and the period difference fraction accumulation register 30 are configured to realize processing that secures sufficient significant digits.

  As described with reference to FIG. 9 of the second embodiment, the period difference data already includes an error (the operation is originally an operation including π, and an operation such as obtaining a square root has a finite effective value. Therefore, what should originally have to be zero actually does not have a value of zero (period difference fraction accumulation register). A reset input signal is added to the period difference fraction accumulation register shown in FIG. 12, and the same initial setting (preset) value is forcibly set for each track. This eliminates the error generated by the calculation and prevents the propagation of the error.

  As a result, the averaging time is set in a range in which the error is equal to or less than the resolution of the period difference setting, so that the obtained clock generation period difference can obtain the same result as when the averaging is not performed.

  Next, as Embodiment 4 of the present invention, the operation when the section for generating the formatter drive clock in Embodiments 1 to 3 is set for each track of the optical disk will be described with reference to FIG.

  Here, a case where the formatter drive clock is generated from the approximate clock cycle described in the second embodiment will be described as an example. Here, the track refers to a rotation angle of 2π of an information track formed in an equal pitch spiral. The track length becomes longer by “2 × π × track pitch length” from the inner periphery to the outer periphery of the optical disc.

  An information track that exactly matches the ideal CLV format is formed at the start or end of the track. In the approximate interval, the information is formed with an ideal information arrangement and error in the CLV format corresponding to the error of the set period, but the phase relationship between adjacent tracks is guaranteed in all tracks within a clear error range.

  The approximate range is not limited to each track, and may be a range smaller than the track. In general, an information track is composed of a series of sectors and a series of blocks composed of a plurality of sectors. These are shorter than the track length, and can be formed while maintaining the phase relationship between adjacent tracks even if approximate data is updated for each sector or block. In this case, considering that recording or reproduction on the optical disk is performed in units of sectors or blocks, the recording / reproduction clock in the sector or block during recording / reproduction is constant, so that the stability of the recording / reproduction characteristics is achieved. Also gives desirable results.

  FIG. 14 is a block diagram showing a schematic configuration of the drive clock generation apparatus according to the fifth embodiment. As shown in FIG. 14, a formatter drive clock generation circuit 20 that generates a formatter drive clock (Fclk), a turntable rotation drive clock (Tclk), and a lateral feed drive clock (Sclk) using the same basic clock generator 17. , A rotation drive clock generation circuit 19 and a lateral feed drive clock generation circuit 18. Also, the formatter drive clock generation circuit 20 includes a formatter drive clock (Fa; constant) at the time of CLV format formation by CLV drive and a CLV formatter drive clock in the CAV drive state generated by the method described in the first to third embodiments. (Fn; n is a track number) can be generated, and CAV driving and CLV driving can be switched by clock switching means (not shown).

  FIGS. 15A and 15B are diagrams showing an example of operation in which the state of each drive clock at the time of forming the CLV format in the CAV drive state and the CLV drive state is approximated for each track. In FIGS. 15A and 15B, n is a variable whose value is changed for each track, a is a constant, and NFn, NTa, NSa are the numbers of generated drive clocks when one track is formed.

  FIG. 15A shows how each drive clock is generated when the CLV format is formed in the CAV drive state. The rotation and lateral feed of the turntable driven by CAV are driven at a constant speed (constant frequency: equivalent to Ta and Sa). The number of clocks per track (NTa, NSa) does not change. The frequency Fn of the formatter drive clock varies from track to track, and the number of formatter drive clocks per track is increased in proportion to “2 × π × track pitch length” (information tracks from the inner periphery of the optical disk). When forming on the outer periphery).

  FIG. 15B is a diagram showing a conventional state of generating each drive clock when forming a CLV format by CLV drive. Since the turntable rotation and the lateral feed are driven by CLV so that the linear velocity is constant, the track period and the frequency (Tn, Sn) for each track change. However, the number of clocks per track (NTa, NSa) does not change. The frequency Fa of the formatter drive clock is constant, and the number of formatter drive clocks per track increases in proportion to “2 × π × track pitch length” for each track (the information track is the inner circumference of the optical disk). To the outer periphery). A method of generating a drive clock relating to the formation of a CLV format by CLV drive is disclosed in Patent Document 6.

  Here, with respect to the formatter drive clock generation circuit as shown in FIG. 4 or FIG. 5 described above, the position count designation value (the clock generation circuit using frequency division is changed by changing the drive state (CLV drive or CAV drive)). CLV format formation operation by preparing a drive clock generation data circuit storing clock data in a storage means such as a RAM as shown in FIG. 16, for example. The CLV format forming operation can be performed by changing the driving state from the CAV driving state to the CLV driving state or from the CLV driving state to the CAV driving state.

  Next, as Example 1 of Embodiment 6 of the present invention, information track exposure processing in an optical disk master exposure apparatus will be described. In the optical disk master exposure apparatus shown in FIG. 1, CLV format exposure by CAV drive, CLV format exposure by CLV drive, or mixed exposure is performed. FIG. 17 shows an exposure example when processing is performed by mixing CLV format exposure by CAV drive and CLV format exposure by CLV drive. In this example, the inner peripheral portion of the optical disc is driven by CAV in order to avoid the occurrence of mechanical vibration caused by a sudden change in the rotational speed of the turntable due to CLV driving, and the outer peripheral portion is driven by CAV to reduce the exposure time. .

  Although the exposure time is the shortest when performing exposure by high-speed CAV driving, the problem of insufficient exposure light intensity accompanying an increase in the exposure linear velocity at the outer peripheral portion occurs, so the output of the laser mounted by the exposure switching means, Alternatively, the driving conditions are appropriately set in consideration of the mechanical rigidity of the apparatus itself.

  Then, by the drive clock generation unit surrounded by the broken line shown in FIG. 1, the lateral feed control circuit 13, the rotational drive control circuit 14, and the format signal generator 16 are laterally driven for CLV format formation by CAV drive. The generation of the clock, the turntable rotation drive clock, and the formatter drive clock, or the transverse feed drive clock, the turntable rotation drive clock, and the formatter drive clock for forming the CLV format by the CLV drive are continuously performed. At the same time, the exposure light beam is meandered by the output of the format signal generator 16 or turned on / off to form an information track, and the light amount modulator 3 performs exposure amount modulation to obtain a fixed shape groove (at the time of CLV driving, there is Although a constant value may be used, it is necessary to modulate the exposure radius position during CAV driving), and optimal exposure of the glass master 5 on which the CLV format is formed is performed.

  As Example 2 of the sixth embodiment, although not particularly illustrated, the drive clock generation device described in the fifth embodiment is mounted, and exposure of either CLV format exposure by CLV drive or CLV format exposure by CAV drive is performed. An optical disc drive apparatus that can also handle the method, and performs writing by switching the driving method depending on the writing area during formation of information pits in the CLV format.

  The optical disk drive apparatus according to the second embodiment includes a drive clock generator, a turntable on which an optical disk medium is placed and rotated by a rotation driving means, and a recording light beam based on an information recording signal for forming an information pit string on the optical disk medium. It is composed of focused irradiation means, lateral feed means for moving the focused irradiation means in parallel with the optical disk medium plane, rotational drive means, and drive control means for controlling the lateral feed drive means.

  The information track of the information pit row is written on the optical disk medium by the drive control means. When writing information, CLV format writing may be performed in the CLV driving state, or CLV format writing may be performed by switching to CLV format writing in the CAV driving state.

  In addition, since the CLV format writing by CAV driving is possible in the optical disc drive apparatus, the optical disc formed in the same phase relationship as the ideal CLV format in the phase relationship between adjacent tracks such as wobble information or pit information formed on the information track. Media can be provided.

  Furthermore, since it is possible to write by switching between CLV format writing by CAV driving and CLV format writing by CLV driving, writing operation to an optical disk medium in which the CLV format forming method is switched according to the information track forming area becomes possible. When writing in the CLV format formed by spiral information tracks having an equal track pitch from the circumference to the outer circumference, the writing time is shortened (inner circumference: CLV drive, outer circumference: CAV drive), and the turn table has a rapid rotation speed. It becomes possible to reduce the mechanical vibration accompanying the change, or to solve the power shortage of writing laser irradiation in the outer periphery exposure when writing by CAV driving (inner circumference; CAV driving, outer circumference: CLV driving).

  As Embodiment 7 of the present invention, the optical disk master exposure apparatus described in Embodiments 1 to 6 can form a CLV format on a glass master in a CAV drive state, and the phase relationship of various information on adjacent tracks However, it is possible to obtain an optical disc master formed / maintained in an obvious relationship, and the recording medium thus created has a phase relationship between adjacent tracks of various information formed on the information track, and a CLV format. It is possible to obtain an optical disc medium that is an information recording medium in which the phase relationship between adjacent tracks is formed to be equal and the crosstalk between adjacent tracks is extremely reduced during reproduction.

  A formatter drive clock generation method, a formatter drive clock generation device, a drive clock generation device, an optical disc master exposure method, an optical disc master exposure device and an optical disc drive device, and an optical disc master and an information recording medium created thereby have a clock generation time By using the clock cycle, the cycle difference, and the average of these values, the formatter drive clock is accurately generated and used to form a CLV format exposure by switchable CLV drive and CAV drive. An information track having an accurate phase relationship between adjacent tracks is formed to suppress crosstalk due to various information on the information track, and is useful for forming a CLV format by CAV driving as an information track by exposure on an optical disc master.

1 is a block diagram showing the basic configuration of an optical disc master exposure apparatus in an embodiment of the present invention Schematically shows a manner of change of the elapsed time t _n according to the first embodiment of the present invention Shows schematically the approximate t _n according to the first embodiment of the present invention 1 is a block diagram showing a schematic configuration of a formatter drive clock generation circuit according to a first embodiment of the present invention. The block diagram which shows schematic structure of the other formatter drive clock generation circuit in Embodiment 1 of this invention. Timing chart of formatter drive clock delayed with resolution equal to or lower than basic clock by specifying basic clock count value and state of each delay pulse in embodiment 1 of the present invention Schematically shows a manner of change of the clock period T _n in the second embodiment of the present invention It shows schematically the approximate clock period T _n in the second embodiment of the present invention The block diagram which shows schematic structure of the formatter drive clock generation circuit in Embodiment 2 of this invention Schematically shows a manner of change of the clock period T _n in the third embodiment of the present invention It shows schematically the approximate clock period T _n in the third embodiment of the present invention The block diagram which shows schematic structure of the formatter drive clock generation circuit in Embodiment 3 of this invention. It shows schematically the approximate clock period T _n when the generation interval of the formatter driving clock according to the fourth embodiment of the present invention was for each track of the optical disk FIG. 5 is a block diagram showing a schematic configuration of a drive clock generation device according to a fifth embodiment of the present invention. FIG. 5A is a diagram showing an operation example in which the state of each drive clock at the time of forming a CLV format in the CLV drive state is approximated for each track in Embodiment 5 of the present invention. The figure which shows the example of a drive clock generation data circuit which stored clock data in memory | storage means, such as RAM, in Embodiment 5 of this invention. The figure which shows the change of the clock processed by mixing the CLV format exposure by CAV drive and the CLV format exposure by CLV drive in Embodiment 6 of this invention A block diagram showing a clock generation circuit for forming a conventional CLV format by CAV driving

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure laser 2 Exposure optical system 3 Light quantity modulator 4 Focus actuator 5 Glass master disk 6,104 Optical modulator 7,103 Encoder 8 Drive motor 9 Linear encoder 10 Air slider motor 11 Slider motor driver 12 Drive motor driver 13 Cross feed control circuit 14 Rotation Drive Control Circuit 15 Controller 16 Format Signal Generator 17 Basic Clock Generator 18 Horizontal Feed Drive Clock Generation Circuit 19 Rotation Drive Clock Generation Circuit 20 Formatter Drive Clock Generation Circuit 21 Counter Circuit 22 Register Circuit 23 Count Value Match Detection Circuit 24 Delay Circuit 25 Period data processing circuit 26 Period generation circuit 27 Period fraction accumulation register 28 Period difference data processing circuit 29 Period data generation circuit 30 Period difference fraction accumulation register

Claims (28)

In an optical disc master exposure apparatus, a formatter drive clock generation method for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master,
The formatter is generated by using a clock generation time obtained from a track pitch, a rotation angular frequency of the optical disc master to be driven by CAV, a basic line segment length of the information track in the CLV format, and a CLV drive start radius position. Drive clock generation method.   And generating an average time interval obtained by dividing an arbitrary clock including a plurality of clocks generated by using the clock generation time by the number of clocks included in the clocks. Item 2. A formatter drive clock generation method according to Item 1.   3. The formatter drive clock generation according to claim 2, wherein the number of clocks to be averaged is set so that a clock position calculated for obtaining the average time interval is equal to or less than a resolution of a pulse generation position. Method. In an optical disc master exposure apparatus, a formatter drive clock generation method for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master,
Generated using the period of the clock train generated by the clock generation time obtained from the track pitch, the rotation angular frequency of the optical disc master driven by CAV, the basic line segment length of the information track in the CLV format, and the CLV drive start radius position A formatter drive clock generation method comprising:   5. The formatter drive according to claim 4, wherein the formatter driving is performed using an average clock period of a clock train included between the clocks between arbitrary clocks including a plurality of clocks generated using the clock generation time. Clock generation method.   6. The formatter drive clock generation according to claim 5, wherein the number of clocks to be averaged is set so that a clock period calculated for obtaining the average clock period is equal to or less than a resolution of a pulse generation period. Method. In an optical disc master exposure apparatus, a formatter drive clock generation method for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master,
Using the period difference of the clock train generated by the track generation time obtained from the track pitch, the rotation angular frequency of the optical disc master driven by CAV, the basic line segment length of the information track in the CLV format, and the CLV drive start radius position A formatter drive clock generation method, comprising: generating a formatter drive clock.   8. The method according to claim 7, wherein, between any clocks including a plurality of clocks generated using the clock generation time, an average difference value of period differences of clock sequences included between the clocks is generated. Formatter drive clock generation method.   9. The formatter according to claim 8, wherein the number of clocks to be averaged is set so that a clock cycle difference calculated to obtain the average clock cycle difference value is equal to or less than a resolution of a pulse generation cycle. Drive clock generation method.   9. The formatter drive clock according to claim 2, wherein an interval for approximation between the clocks is performed for each track or in a unit smaller than the track between arbitrary clocks including the plurality of clocks. Generation method. In an optical disc master exposure apparatus, a formatter drive clock generation method for forming an equal pitch spiral information track having a CLV format on a CAV-driven optical disc master,
The number of formatter drive clocks included in the rotation angle is increased by a certain integer for each arbitrary rotation angle of the CLV format formed by the formed information tracks having the equal pitch spiral. In the CLV format formation, a formatter drive clock generation method, wherein a value of a period fraction accumulation register or a period difference fraction accumulation register is initialized for each formatter drive clock corresponding to the arbitrary rotation angle. An optical disk master exposure apparatus, comprising: a formatter drive clock generator for forming an information pitch spiral-shaped information track having a CLV format on a CAV-driven optical disk master,
Detecting means for obtaining values of a track pitch, a rotation angular frequency of the optical disk master to be driven by CAV, a basic line segment length of the information track in the CLV format, and a CLV driving start radius position; and a value obtained by the detecting means An apparatus for generating a formatter drive clock, comprising: a calculation means for obtaining a clock generation time based on the counter; and a count means for generating a formatter drive clock according to an output of the calculation means.   An average calculation unit that obtains an average time interval obtained by dividing by a number of clocks included between the clocks between arbitrary clocks including a plurality of clocks generated using the clock generation time of the arithmetic unit, 13. The formatter drive clock generation apparatus according to claim 12, wherein the formatter drive clock is generated by a counting unit in accordance with an output of the average calculation unit.   14. The formatter drive according to claim 13, further comprising setting means for setting the number of clocks to be averaged so that a clock position calculated by the average calculating means is equal to or less than a resolution of a pulse generation position. Clock generator. An optical disk master exposure apparatus, comprising: a formatter drive clock generator for forming an information pitch spiral-shaped information track having a CLV format on a CAV-driven optical disk master,
Detecting means for obtaining values of a track pitch, a rotation angular frequency of the optical disk master to be driven by CAV, a basic line segment length of the information track in the CLV format, and a CLV driving start radius position; and a value obtained by the detecting means An apparatus for generating a formatter drive clock, comprising: arithmetic means for obtaining a cycle of a clock train generated based on a clock generation time based thereon; and count means for generating a formatter drive clock in accordance with an output of the arithmetic means.   An average calculating means for obtaining an average clock period of a clock train included between the clocks between arbitrary clocks including a plurality of clocks generated using the clock generation time of the calculating means, and an output of the average calculating means 16. The formatter drive clock generating apparatus according to claim 15, wherein the formatter drive clock is generated by a counting means in response to the above.   17. The formatter according to claim 16, further comprising setting means for setting the number of clocks to be averaged so that an average clock period calculated by the average calculating means is equal to or less than a resolution of a pulse generation period. Drive clock generator. An optical disk master exposure apparatus, comprising: a formatter drive clock generator for forming an information pitch spiral-shaped information track having a CLV format on a CAV-driven optical disk master,
Detecting means for obtaining values of a track pitch, a rotation angular frequency of the optical disk master to be driven by CAV, a basic line segment length of the information track in the CLV format, and a CLV driving start radius position; and a value obtained by the detecting means An apparatus for generating a formatter drive clock, comprising: arithmetic means for obtaining a period difference of a clock train generated based on a clock generation time based thereon; and count means for generating a formatter drive clock in accordance with an output of the arithmetic means.   Average calculating means for obtaining an average difference value of period differences of clock trains included between the clocks among arbitrary clocks including a plurality of clocks generated using the clock generation time of the arithmetic means, and the average calculation 19. The formatter drive clock generating apparatus according to claim 18, wherein the formatter drive clock is generated by the counting means in accordance with the output of the means.   20. The formatter according to claim 19, further comprising setting means for setting the number of clocks to be averaged so that a clock period difference calculated by the average calculating means is equal to or less than a resolution of a pulse generation period. Drive clock generator.   20. The average calculation means performs an interval for approximating the clocks between arbitrary clocks including a plurality of clocks for each track or in units smaller than the tracks. Formatter drive clock generator. An optical disk master exposure apparatus, comprising: a formatter drive clock generator for forming an information pitch spiral-shaped information track having a CLV format on a CAV-driven optical disk master,
The number of formatter drive clocks included in the rotation angle is increased by a certain integer for each arbitrary rotation angle of the CLV format formed by the formed information tracks having the equal pitch spiral. An apparatus for generating a formatter drive clock, comprising: means for initially setting a value of a period fraction accumulation register or a period difference fraction accumulation register for each formatter drive clock corresponding to an arbitrary rotation angle in CLV format formation. 23. A formatter drive clock generation device according to claim 12, a turntable on which an optical disc master is placed and rotated by a rotation driving means, and an information recording signal for forming an information track on the optical disc master. Recording light beam convergent irradiating means, lateral feed driving means for moving either the turntable or the convergent irradiating means in a direction parallel to the optical disk master plane, the rotational driving means, and the laterally feeding drive means. A drive clock generating device for an optical disc master exposure apparatus for forming information tracks having various formats on the optical disc master by the drive control means,
The same reference clock generating means used for the turntable rotation drive clock, the lateral feed drive clock, and the formatter drive clock, and the clock switch means for the formatter drive clock used for the CLV format formation in the CLV drive state and the CLV format formation in the CAV drive state. A drive clock generator characterized by the above. 24. A drive clock generating device according to claim 23, a turntable on which an optical disk master is mounted and rotated by rotation driving means, and a convergent irradiation of a recording light beam based on an information recording signal for forming an information track on the optical disk master Means, lateral feed drive means for moving one of the turntable or the convergent irradiation means in a direction parallel to the optical disc master plane, and drive control means for controlling the rotational drive means and the lateral feed drive means. An optical disc master exposure method for forming an information track having various formats on the optical disc master by controlling the rotation driving means and the lateral feed driving means of the drive control means by using an optical disc master exposure apparatus having:
An optical disk master exposure method, wherein CLV format exposure is performed by switching between CLV format exposure in a CLV drive state and CLV format exposure in a CAV drive state. 24. A drive clock generating device according to claim 23, a turntable on which an optical disk master is mounted and rotated by rotation driving means, and a convergent irradiation of a recording light beam based on an information recording signal for forming an information track on the optical disk master Means, lateral feed drive means for moving one of the turntable or the convergent irradiation means in a direction parallel to the optical disc master plane, and drive control means for controlling the rotational drive means and the lateral feed drive means. An optical disc master exposure apparatus for forming information tracks having various formats on the optical disc master by the drive control means,
An optical disk master exposure apparatus, comprising exposure switching means for CLV format exposure in a CLV drive state and CLV format exposure in a CAV drive state, and performing CLV format exposure. 24. A drive clock generation device according to claim 23, a turntable on which an optical disk medium is mounted and rotated by rotation driving means, and a convergent irradiation of a recording light beam based on an information recording signal for forming an information bit string on the optical disk medium Means, lateral feed drive means for moving one of the turntable or the convergent irradiation means in a direction parallel to the plane of the optical disk medium, and drive control means for controlling the rotational drive means and the lateral feed drive means. An optical disk drive device for forming an information track of the information bit string having various formats on the optical disk medium by the drive control means,
An optical disk drive device comprising: CLV format writing in a CLV driving state and CLV format writing switching in a CAV driving state, and performing CLV format writing.   26. An optical disc master, wherein an information pitch spiral-shaped information track having a CLV format is formed in a CAV drive state using the optical disc master exposure apparatus according to claim 25.   28. An information recording medium comprising an information track having an equal pitch spiral shape having a CLV format on an optical disc master produced by the optical disc master according to claim 27 and driven by CAV.

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