JPH1049871A - Apparatus for exposing original optical-disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form information latent image pits accurately at a stable pit position all over the face of a glass substrate. SOLUTION: In the original optical-disk-exposing apparatus, a photoresist film is formed on an original optical disk 105, and thereafter an exposing laser light modulated with an information signal is projected to the photoresist film while the optical disk 105 is rotated and transferred laterally, thereby to form an information latent image pit on the original optical disk 105. The apparatus is provided with a pulse generator 101 which, when a system clock is input thereto, operates a value dividing a frequency of the system clock in accordance with a time required for one rotation of the optical disk 105, divides the system clock by the operated value, and outputs a TPG (rotation command pulse) controlling the rotation of the optical disk 105, an SPG (lateral feed command pulse) controlling the lateral feed of the original optical disk 105 and an FPG (reference pulse) controlling outputting of an information signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk master exposure apparatus, and more particularly, to a drive signal for rotation / transverse feed of a glass substrate and an output timing of information recorded as latent image pits on the glass substrate. By obtaining signals by dividing the same system clock,
The present invention relates to an optical disk master exposure apparatus capable of forming a latent image pit at a stable pit position over the entire surface of a glass substrate.

[0002]

2. Description of the Related Art As a conventional optical disk master exposure apparatus, there is one disclosed in Japanese Patent Application Laid-Open No. 3-113829, "master recording apparatus". This master disc recording device detects the rotation fluctuation signal from the encoder signal of the motor that rotates the optical disk master, and prevents the displacement of the information signal latent image pit position shift due to the rotation fluctuation by changing the reference clock of the recording information signal. It is.

As a conventional optical disk master exposure apparatus, there is one disclosed in Japanese Patent Application Laid-Open No. 2-156440, "Optical disk master recording apparatus". This optical disk master recording apparatus divides the frequency of an encoder signal of a motor for rotating the optical disk master and obtains a rotation synchronization signal for each rotation of the master so that the recording start position of the information recording signal coincides with the radial direction of the optical disk master. That is.

[0004]

Problems to be Solved by the Invention
In the master disc recording device disclosed in Japanese Patent Application Laid-Open No. 9-205, it is possible to prevent the positional deviation of the information latent image pits to some extent. However, in the master recording apparatus, since control for suppressing the fluctuation of the rotation of the motor to a relatively small level is generally performed, it is not practically necessary to correct the information signal due to the fluctuation of the rotation. Conversely, by changing the reference clock of the recording information signal, it is possible to prevent the positional deviation of the information signal latent image pit due to the rotation fluctuation by adopting a configuration, that is, to follow the rotation fluctuation, V, V
There is a possibility that problems such as difficulty in adjusting the -F conversion constant may occur.

Further, MCAV (Modified Co.)
nstant Angle Velocity: quasi-angular velocity constant, MCLV (Modified Consta
ntLinear Velocity: Constant linear velocity
In the master recording by the method, information is recorded by changing the reference clock of the information signal generator for each of a plurality of zones. However, in the master recording apparatus disclosed in Japanese Patent Application Laid-Open No. 3-113829, since the reference clock is made variable to prevent the displacement of the information latent image pit, the master exposure is performed using the MCAV and MCLV methods. It is difficult to do.

On the other hand, in the optical disk master recording apparatus disclosed in Japanese Patent Application Laid-Open No. 2-156440, it is possible to match the recording start position of the information recording signal in the radial direction of the optical disk master, but the rotation of the optical disk master is not possible. Since the fluctuation is absorbed by any one of the sectors, there is a problem that the fluctuation of the sector length occurs in one track. Further, it is possible to make the recording start position of the information recording signal coincide with the radial direction of the optical disk master by dividing the encoder signal of the motor for rotating the optical disk master to obtain a rotation synchronization signal for each rotation of the master. However, in the master recording apparatus, since control for suppressing the rotation fluctuation of the motor is generally performed considerably, it is not practically necessary to correct the information signal due to the rotation fluctuation. vice versa,
As with the master recording apparatus disclosed in JP-A-3-113829, a side effect of employing the configuration disclosed in JP-A-2-156440, that is, following fluctuations in rotation, and FV, V- There is a possibility that problems such as difficulty in adjusting the F conversion constant may occur.

The present invention has been made in view of the above, and has as its object to enable information latent image pits to be accurately formed at stable pit positions over the entire surface of a glass substrate.

[0008]

According to a first aspect of the present invention, there is provided an optical disk master exposing apparatus, comprising: forming a photoresist film on a glass substrate; and rotating and laterally moving the glass substrate. A film is irradiated with an exposure laser beam modulated by an information signal to form an information latent image pit on the glass substrate. In an optical disk master exposure apparatus, a system clock is inputted, and the glass substrate is rotated N times (N is an integer). A first pulse for controlling the rotation of the glass substrate, a first pulse for controlling the rotation of the glass substrate, and a lateral feed of the glass substrate are calculated by dividing the system clock by the calculated division value. Control the second
A pulse generating means for outputting a third pulse for controlling the output of the information signal and the information signal; a rotating means for rotating the glass substrate based on the first pulse; and a rotating means for rotating the glass substrate based on the second pulse. Traversing means for traversing the glass substrate; information signal generating means for outputting the information signal recorded on the glass substrate as the information latent image pits based on the third pulse; Laser light output means for outputting the exposure laser light to irradiate thereon, and information latent image pit formation for modulating the exposure laser light based on the information signal and irradiating the modulated exposure laser light onto the glass substrate Means.

According to a second aspect of the present invention, there is provided an exposure apparatus for exposing an optical disk master, comprising: forming a photoresist film on a glass substrate; and rotating and laterally moving the glass substrate while modulating the photoresist film with an information signal. Irradiate,
In the optical disk master exposure apparatus for forming information latent image pits on the glass substrate, a system clock is input,
A frequency division value for dividing the system clock is calculated according to 1 / N rotation of the glass substrate (N is an integer), and the system clock is frequency-divided by the calculated frequency division value to rotate the glass substrate. Pulse generating means for outputting a first pulse for controlling the horizontal movement of the glass substrate, a second pulse for controlling the lateral feed of the glass substrate, and a third pulse for controlling the output of the information signal;
A rotation unit configured to rotate the glass substrate based on the first pulse; a traverse unit configured to traverse the glass substrate based on the second pulse; and a traverse unit configured to traverse the glass substrate based on the third pulse. Information signal generating means for outputting the information signal recorded on the glass substrate as information latent image pits, laser light output means for outputting the exposure laser light for irradiating on the glass substrate, based on the information signal Information pit forming means for modulating the exposure laser light and irradiating the modulated exposure laser light onto the glass substrate.

According to a third aspect of the present invention, there is provided an optical disk master exposure apparatus, wherein after forming a photoresist film on a glass substrate, the exposure laser beam modulated by the information signal on the photoresist film while rotating and laterally moving the glass substrate. Irradiate,
In the optical disk master exposure apparatus for forming information latent image pits on the glass substrate, a system clock is input,
A frequency dividing value for dividing the system clock is calculated according to a time required for one rotation of the glass substrate, and the system clock is frequency-divided by the calculated frequency dividing value to control rotation of the glass substrate. Pulse generating means for outputting one pulse, a second pulse for controlling the lateral feed of the glass substrate, and a third pulse for controlling the output of the information signal; and the glass substrate based on the first pulse. Rotating means for rotating the glass substrate, traversing means for traversing the glass substrate based on the second pulse, and recording on the glass substrate as the information latent image pits based on the third pulse. Information signal generating means for outputting the information signal,
A laser light output unit that outputs the exposure laser light to irradiate the glass substrate; and an information latent light that modulates the exposure laser light based on the information signal and irradiates the modulated exposure laser light onto the glass substrate. Image pit forming means.

According to a fourth aspect of the present invention, there is provided an optical disk master exposing apparatus according to any one of the first to third aspects, wherein the pulse generating means includes the first optical disk.
Calculation control means for calculating a divided value for obtaining a third pulse, and first frequency dividing means for dividing the system clock based on the divided value and outputting the first pulse A second frequency divider that divides the system clock based on the divided value and outputs the second pulse; and a frequency divider that divides the system clock based on the divided value. And third dividing means for outputting three pulses.

According to a fifth aspect of the present invention, there is provided an optical disk master exposure apparatus according to the fourth aspect.
The arithmetic control means adds a fractional part included in a frequency division value for obtaining the first pulse every time the first pulse is output, and carries when the added value exceeds one. A signal is output, and the carry signal and the integer part of the frequency division value are added and output as a frequency division value for obtaining the first pulse.

According to a sixth aspect of the present invention, there is provided an optical disk master exposure apparatus according to the fourth aspect.
The arithmetic control means adds a decimal part included in a frequency division value for obtaining the second pulse every time the second pulse is output, and carries when the added value exceeds one. A signal is output, and the carry signal and the integer part of the frequency division value are added and output as a frequency division value for obtaining the second pulse.

According to a seventh aspect of the present invention, there is provided an optical disk master exposure apparatus according to the fourth aspect.
The arithmetic control means adds a decimal part included in a frequency division value for obtaining the third pulse every time the third pulse is output, and carries when the added value exceeds one. A signal is output, and the carry signal and the integer part of the frequency division value are added and output as a frequency division value for obtaining the third pulse.

[0018] In a further preferred embodiment of the present invention, there is provided an optical disc master exposing apparatus according to the fourth aspect.
The arithmetic control unit receives the third pulse and divides the third pulse by using an information amount recorded on one track of the glass substrate as a division value,
This is to detect that the third pulse has been output for one track.

According to a ninth aspect of the present invention, in the optical disk master exposing apparatus according to any one of the first to third aspects, the pulse generating means may reduce a time required for one rotation of the glass substrate. When changing in several steps in proportion to the radius of the glass substrate, the frequency of the first pulse for controlling the rotation of the glass substrate according to the change in the time required for one rotation of the glass substrate and the frequency of the glass substrate This is to change the frequency of the second pulse for controlling the traverse feed.

According to a tenth aspect of the present invention, there is provided the optical disk master exposing apparatus according to any one of the first to third aspects, wherein the pulse generating means determines a time required for one rotation of the glass substrate. When changing in proportion to the radial position for each rotation of the glass substrate, the frequency of the first pulse and the second pulse is changed and output within the time required for one rotation of the glass substrate The first and second pulse numbers are constant, and the third
And the third pulse number output within the time required for one rotation of the glass substrate is made constant by changing the frequency of the pulse.

According to a eleventh aspect of the present invention, in the optical disk master exposing apparatus according to the tenth aspect, the pulse generating means changes a frequency of the third pulse, and the pulse generating means changes the frequency of the glass substrate per one rotation. Is increased in several steps.

According to a twelfth aspect of the present invention, in the optical disc master exposing apparatus according to the eleventh aspect, the rotation control means rotates the glass substrate in synchronization with the first pulse, and The feeding means is for horizontally feeding the glass substrate in synchronization with the second pulse.

According to a thirteenth aspect of the present invention, there is provided the optical disk master exposing apparatus according to the twelfth aspect, wherein the amount of the exposure laser light irradiated onto the glass substrate by the information latent image pit forming means is reduced. It is constant over the entire exposure area on the glass substrate.

Further, according to a fourteenth aspect of the present invention, in the optical disc master exposing apparatus according to the eleventh aspect, when the pulse generating means increases the third pulse number, the pulse generating means divides the third pulse number into 24 steps. The third pulse number is increased and 43152 pulses are increased in each step.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an optical disk master exposure apparatus according to the present invention will be described below with reference to [Embodiment 1, Embodiment 2, Embodiment 3], [Embodiment 4],
Embodiment 5 and Embodiment 6 will be described in detail with reference to the drawings.

[Embodiment 1] FIG. 1 is a block diagram showing the arrangement of an optical disk master exposure apparatus according to Embodiment 1. FIG.
The optical disk master exposure apparatus shown in FIG.
After forming a photoresist film on the optical disk master 5
5 irradiates the photoresist film with an exposure laser beam modulated by an information signal while rotating and traversing 5 to form information pits on the optical disc master 105 under the control of the host computer 100. A system clock is input, a frequency division value for dividing the system clock is calculated according to N rotations or 1 / N rotation of the optical disk master 105 (N is an integer), and the system clock is frequency-divided by the calculated frequency division value. 3. A rotation command pulse (TPG) for controlling the rotation of the optical disk master 105 by using
), A traverse command pulse (SPG: corresponding to the second pulse according to claims 1 and 2) for controlling the traverse of the optical disk master 105, and a reference pulse (FPG) for controlling the output of the information signal. A pulse generator (PG) 101 (corresponding to a pulse generating means according to claims 1 and 2) for outputting a third pulse according to claims 1 and 2, and an optical disk master 105 based on TPG. Motor controller 102, spindle motor (M1) 103 and turntable 104 (corresponding to the rotating means according to claims 1 and 2) for rotating the optical disk, and a transverse feed motor controller for transversely moving the optical disk master 105 based on the SPG. 106, a traverse motor (M2) 107, and a traverse stage 108 (claims 1 and 2). To correspond to the lateral feeding means), FPG
Based on the optical disc master 10 as information latent image pits.
An information signal generator (format generator: FG) 109 for outputting an information signal to be recorded on the information processing device 5 (claim 1).
And an Ar laser 112 (corresponding to the laser light output means according to claims 1 and 2) for outputting an exposure laser light for irradiating the optical disk master 105, and a host computer. A light quantity light modulator 115 and a light quantity modulator driver 116 for controlling the light quantity of the exposure laser light based on the control of 100, modulate the exposure laser light based on the information signal, and apply the modulated exposure laser light on the optical disk master 105. A signal light modulator 111 and a signal modulator driver 110 for irradiating light, and an objective lens 114 (corresponding to the information latent image pit forming means according to claims 1 and 2) for condensing modulated exposure laser light; have. In FIG. 1, reference numeral 113 denotes a mirror for reflecting the exposure laser light and changing the optical path.

Next, the configuration and operation of each unit constituting the optical disk master exposure apparatus will be described in detail.

The optical disk master 105 is formed by applying a photosensitive photoresist on a glass plate. Then, the optical disk master 105 is securely fixed on the turntable 104 by vacuum suction.

The spindle motor controller 102
Based on the PLL control synchronized with the rotation command pulse (TPG), the spindle motor (M1) 103 is driven to rotate the turntable 104 on which the optical disk master 105 is mounted. The spindle motor (M1) 103 is provided with an encoder (E: rotary encoder) 117, and the PLL control can be realized by feeding back an output signal of the encoder 117 to the spindle motor controller 102.

The turntable 104 and the spindle motor 103 are mounted on a traverse stage 108. The traverse motor controller 106 drives the traverse motor (M2) 107 based on the PLL control synchronized with the traverse command pulse (SPG) to drive the traverse stage 108
Sideways. As a result, the turntable 104 rotated and driven by the spindle motor 103 can be fed laterally. The transverse feed motor 107 is provided with an encoder (E: rotary encoder) 118. By feeding back the output signal of the encoder 118 to the transverse feed motor controller 106,
LL control can be realized. Also, encoder 1
The PLL control can also be performed by providing a linear encoder (not shown) on the traverse stage 108 and feeding back the output signal of the linear encoder to the traverse motor controller 106 instead of providing the 18 on the traverse motor 107. Can be realized.

The pulse generator (PG) 101 generates a rotation command pulse (TPG) and a traverse command pulse (SPG) for controlling the rotation and traverse of the turntable 104 described above under the control of the host computer 100. The pulse generator 101 can synchronize and generate a signal of an arbitrary frequency.

For example, CAV (Constant Ang)
le Velocity: constant rotation angular velocity and constant lateral feed of the turntable 104).
4 is driven, the TPG and the SPG have constant frequencies according to the angular speed and the traverse speed of the turntable 104.
And can be synchronized.

Also, CLV (Constant Lin)
(Ear Velocity: variable rotation angular velocity and variable lateral feed of the turntable 104)
When driving the optical disk 04, TPG and SPG of variable frequencies can be generated synchronously so that the linear velocity at the point where the laser spot hits the optical disk master 105 is constant.

The Ar laser 112 outputs an exposure laser beam, the output laser beam is narrowed down to an extremely small level by the objective lens 114, and the laser spot is irradiated on the optical disk master 105. Then, on the optical disk master 105,
A latent image pit is formed according to the presence or absence of laser spot irradiation.

The latent image pits on the optical disk master 105 are formed by controlling the irradiation of the exposure laser light by the light amount light modulator 115 and the signal light modulator 111. The optical modulator for light amount 115 is the optical disk master 105.
Is used to control the amount of exposure laser light to be applied to the substrate. The light quantity modulator driver 116 receives the command signal output from the host computer 100 and controls the light quantity light modulator 115 to output an exposure laser beam having a light quantity proportional to the voltage of the command signal. For example, when the turntable 104 is driven by CLV so that the linear velocity at the point where the laser spot hits the optical disk master 105 is constant, the amount of the exposure laser light irradiated onto the optical disk master 105 is over the entire surface of the optical disk master 105. It will be constant. That is, when the host computer 100 outputs a command signal of a constant voltage, the optical disc master 1
The light amount of the exposure laser light irradiated on the optical disk 05 can be kept at a constant level over the entire surface of the optical disk master 105.

On the other hand, the signal light modulator 111 turns on / off the laser light output from the Ar laser 112. The information signal generator 109 receives the reference pulse (FPG) output from the pulse generator 101, controls the signal modulator driver 110 in synchronization with the FPG, and turns on the exposure laser light to the signal light modulator 111.・ Turn off.

The optical disk master 105 on which the latent image pits are formed as described above is developed and subjected to an electroforming process to form a mold (stamper) for forming an optical disk from the optical disk master 105 by molding. Master optical disc 10
The latent image pits formed on 5 correspond to pits and grooves on an optical disk formed from a stamper.

Next, the pulse generator 101 for outputting the rotation command pulse (TPG), the traverse command pulse (SPG) and the reference pulse (FPG) will be described in more detail.

Based on the position of the laser spot narrowed by the objective lens 114, the number of TPG pulses required to rotate the optical disk master 105 spirally at a track pitch TP, for example, N (1 / N rotation) is K1. × N,
The number of pulses of the SPG is set to K2 × N.

The amount of information recorded per N tracks on the optical disk is known in advance. This information amount is determined by the number of channel bits (cb) (FP output per N tracks).
G may be considered as the number of clocks), and is expressed as K3 × N.

The required frequencies of TPG, SPG and FPG are K1 × ROT (rps) and K2 × ROT, respectively.
(Rps) and K3 × ROT (rps). These can all be obtained by dividing the same system clock. The ROT is the turntable 104
Is the number of rotations.

Here, a method of dividing the system clock by the pulse generator 101 to obtain TPG / SPG / FPG will be described.

FIG. 2 is a block diagram showing a schematic configuration of the pulse generator 101 used in the optical disk master exposure apparatus of the first embodiment. Pulse generator 1
Reference numeral 01 denotes a first frequency divider 200 which receives a system clock output from an external system clock generator 203, divides the system clock and outputs an FPG, and divides the system clock and outputs a TPG. And a third frequency divider 202 that divides the system clock and outputs an SPG.

The system clock used in the pulse generator 101 is set to 200 MHz, the dividing value of TPG is set to Nt, the dividing value of SPG is set to Ns, and the dividing value of FPG is set to N
Assuming that f, Nt = ROT × 20000000 / K1 Ns = ROT × 20000000 / K2 Nf = ROT × 20000000 / K3

Each of the frequency dividers 200 to 202 shown in FIG. 2 divides the system clock using the frequency division value obtained as described above, and outputs TPG, SPG, and FPG.

The processing when the frequency division value includes a decimal part will be described. FIG. 3 is an explanatory diagram for explaining processing in the pulse generator 101 in the case where the frequency division value of each of TPG, SPG, and FPG includes a decimal part. However, in each of the TPG, SPG, and FPG, the processing when the frequency division value includes a decimal part is the same, and for convenience of description, FIG. 3 will exemplify the case of FPG.

It is assumed that the integer part of the frequency division value (FPG) is N0 and the decimal part is N1. When the frequency division of the system clock is repeated at N0, the difference from the true frequency division value (Nf) is accumulated. Therefore, the pulse Pn after frequency division by the frequency divider 200
Is fed back to the MPU 200 (corresponding to the arithmetic control means in claim 4), and N1 is added every time the pulse Pn is generated. The value obtained by adding N1 is defined as SN1. MPU300
Outputs a P1 signal as a carry signal when SN1 exceeds "1" as a result of sequentially adding N1. That is, the P1 signal is normally “0”, but the SN1
Becomes "1" when exceeds "1". Subsequently, the P1 signal is added to N0 by the adder 301, and the frequency divider 200 divides the system clock by the frequency division value N0 + 1. At this time, the MPU 300 adds N0-1 to SN1 to reduce the accumulated difference. When SN1 is 1 or less, the frequency division value is N0 which is an integer part. By repeating this process, it is possible to perform a frequency division process close to the frequency division by the true frequency division value.

In FIG. 3, the DTP is a frequency divider 20.
This is data for obtaining the track pulse TP by dividing the frequency of the pulse Pn divided by 0 by the frequency divider 302. In the case of FPG, cb is set as DTP. T
By monitoring P, it is possible to detect that a pulse for one track has been output.

The above-described processing is completed in the time required for the turntable 104 to make N rotations (1 / N rotation). CAV
In the case of the system, if the time required for the turntable 104 to rotate next N times does not change, the process currently being performed is continued. On the other hand, in the case of the CLV method, the linear velocity V (m / s), which is CLV driving data, and the driving start position R0
(Mm), given the track pitch PT (μm), the time T required for the turntable 104 to make N rotations
T = 2 × π × R0 × 1000 × N / (V × 100,000
0). Since the track pitch PT × N is added to R0 every N rotations, the time T required for the turntable 104 to make N rotations changes. When the time required for one rotation of the turntable 104 changes for each track as in the CLV method, the frequency division value is updated each time.

As described above, according to the optical disk master exposure apparatus of the first embodiment, the rotation / transverse drive signal (TPG / SPG) of the optical disk master 105 and the reference pulse (FPG) of the information signal generator 109 are the same. Of each of the system clocks, and based on the time per 105 N rotations (1 / N rotation) of the master optical disc 105, the respective division values are obtained. The division values are appropriately determined so that the division error does not accumulate. Since the TPG / SPG / FPG is generated instead (processing of the decimal part included in the frequency division value), stable pit position accuracy can be obtained over the entire surface of the optical disk master 105.

[Second Embodiment] FIG. 4 is a block diagram of an optical disk master exposure apparatus according to a second embodiment of the present invention. The optical disk master exposure apparatus shown in FIG. 2 forms a photoresist film on the optical disk master 105, and then irradiates the photoresist film with an exposure laser beam modulated by an information signal while rotating and moving the optical disk master 105 laterally. It forms a latent image pit, receives a system clock, calculates a frequency dividing value for dividing the system clock according to the time required for one rotation of the optical disk master 105, and calculates the system clock using the calculated frequency dividing value. , A rotation command pulse (TPG: corresponding to the first pulse according to claim 3) for controlling rotation of the optical disk master 105,
A lateral feed command pulse (SPG: corresponding to the second pulse according to claim 3) for controlling the lateral feed of the optical disk master 105 and a reference pulse (FP) for controlling the output of the information signal.
G: a pulse generator (PG) 101 (corresponding to a pulse generating means according to claim 3) for outputting a third pulse according to claim 3, and a spindle for rotating the optical disk master 105 based on TPG. A motor controller 102 (corresponding to the rotating means according to claim 3),
Spindle motor 103 driven by spindle motor controller 102 and spindle motor 103
A turntable 104 (corresponding to the rotating means according to claim 3) driven by the motor, a traverse motor controller 106 for traversing the optical disk master 105 based on the SPG, and a traverse motor driven by the traverse motor controller 106 A transverse feed stage 108 (corresponding to a transverse feed means described in claim 3) driven by a transverse feed motor 107 and a transverse feed motor 107 to horizontally feed the optical disc master 105, and information latent image pits on the optical disc master 105 based on the FPG. An information signal generator (format generator: FG) 1 for outputting an information signal to be recorded
09 (corresponding to the information signal generating means according to claim 3)
An Ar laser 112 (corresponding to a laser light output means according to claim 3) for outputting an exposure laser light to be irradiated onto the optical disk master 105; an exposure laser modulated by modulating the exposure laser light based on an information signal; Light is used for optical disc master 1
5, an optical modulator 401 for irradiating the light modulator 401, a modulator driver 400 for driving the optical modulator 401, and an objective lens 114 for condensing the modulated exposure laser light (corresponding to the information latent image pit forming means according to claim 3). ). In FIG. 4, reference numeral 113 denotes a mirror for reflecting the exposure laser light and changing the optical path.

Next, the configuration and operation of each component of the optical disk master exposure apparatus will be described in detail.

The optical disk master 105 is formed by applying a photosensitive photoresist on a glass plate. Then, the optical disk master 105 is securely fixed on the turntable 104 by vacuum suction.

The spindle motor controller 102
Based on the PLL control synchronized with the rotation command pulse (TPG), the spindle motor (M1) 103 is driven to rotate the turntable 104 on which the optical disk master 105 is mounted. In addition, the turntable 104 and the spindle motor 103 are mounted on a horizontal feed stage 108. The traverse motor controller 106 drives the traverse motor (M2) 107 based on PLL control synchronized with the traverse command pulse (SPG) to drive the traverse stage 1
08 is traversed. As a result, the spindle motor 103
, The turntable 104 being driven to rotate can be fed sideways.

The pulse generator (PG) 101 generates a rotation command pulse (TPG) and a traverse command pulse (SPG) for controlling the rotation and traverse of the turntable 104 described above under the control of the host computer 100. The pulse generator 101 can synchronize and generate a signal of an arbitrary frequency.

For example, CAV (Constant Ang)
le Velocity: constant rotation angular velocity and constant lateral feed of the turntable 104).
4 is driven, the TPG and the SPG have constant frequencies according to the angular speed and the traverse speed of the turntable 104.
And can be synchronized.

Also, CLV (Constant Lin)
(Ear Velocity: variable rotation angular velocity and variable lateral feed of the turntable 104)
When driving the optical disk 04, TPG and SPG of variable frequencies can be generated synchronously so that the linear velocity at the point where the laser spot hits the optical disk master 105 is constant.

The Ar laser 112 outputs an exposure laser beam, the output laser beam is narrowed down to a very small level by the objective lens 114, and the laser spot is irradiated on the optical disk master 105. Then, on the optical disk master 105,
A latent image pit is formed according to the presence or absence of laser spot irradiation.

The light modulator 111 is provided between the Ar laser 112 and the objective lens 114 to form a latent image pit. This optical modulator 111 is an Ar laser 11
2 has a function of turning on / off the laser light output from the laser light 2, and is controlled by a pulse signal from an information signal generator (FG) 109 and a modulator driver 110. The information signal generator 109 operates in synchronization with the reference signal (FPG) output from the pulse generator 101 described above.

The optical disk master 105 on which the latent image pits are formed as described above is developed and subjected to an electroforming process to form a mold (stamper) for forming an optical disk from the optical disk master 105 by molding. Master optical disc 10
The latent image pits formed on 5 correspond to pits and grooves on an optical disk formed from a stamper.

Next, the pulse generator 101 for outputting the rotation command pulse (TPG), the traverse command pulse (SPG) and the reference pulse (FPG) will be described in further detail.

The number of TPG pulses required to rotate the optical disk master 105 in a spiral at a track pitch of 1.6 μm with reference to the position of the laser spot narrowed by the objective lens 114 is 4000, and the number of pulses of the SPG is 200.

When the turntable 104 is driven by the CAV method, the rotation speed is set to ROT (rpm),
If the track pitch is 1.6 μm, the turntable 1
The time T of one rotation of 04, the frequency TP of TPG, and the frequency SP of SPG are as follows: T = 60 / ROT TP = 4000 / T = 4000 × ROT / 60 SP = 200 × ROT / 60

For example, when the rotational speed ROT is 300 rpm (5 rpm)
ps: The time required for one rotation of the turntable 104 is 0.2 sec) and the track pitch is 1.6 μm.
The frequency TP of the TPG is 20000 Hz, and the frequency SP of the SPG is 1000 Hz. T having such a frequency
The rotation of the optical disc master 105 is performed by the PG / SPG.
Lateral feed is controlled.

In a state where the optical disk master 105 is rotated and fed sideways based on TPG / SPG, the information signal generator 1
A latent image pit is formed on the master optical disk 105 by the output signal from the optical disk 09. The amount of information that can be recorded per track of the optical disk is known in advance. The information amount is represented by the number of channel bits (cb). For example, the cb number of a 3.5-inch optical disk is 290000 cb. The number of cb is one pulse generator per track.
It is equivalent to the number of clocks of the reference pulse (FPG) output from 01. Therefore, the frequency FP of the FPG is
P = 290000.ROT / 60. Similarly to the above example, when the rotational speed ROT is 300 rpm, the frequency of the FPG is 1450000 Hz. Thus, the pulse generator 101 outputs an FPG having a constant frequency of 1450000 Hz.

The above-described TPG, SPG, and FPG can be obtained by dividing the same system clock in the pulse generator 101. However, the configuration of the pulse generator 101 for obtaining the TPG / SPG / FPG is as shown in FIG. 2, and the description of the configuration is omitted here.

The system clock used in the pulse generator 101 is 200 MHz, the frequency division value of the FPG is Nf, the frequency division value of the TPG is Nt, and the frequency division value of the SPG is N
If s, then Nf = 20000000 / FP Nt = 20000000 / TP Ns = 20000000 / SP.

In the case of the above example, TP = 20,000 Hz,
Since SP = 1000 Hz and FP = 14500000 Hz, Nf = 13.7310... Nt = 10000 Ns = 200000.

Each of the frequency dividers 200 to 202 shown in FIG. 2 divides the system clock using the frequency division value obtained as described above, and outputs TPG, SPG, and FPG.

Here, a case where the frequency division value includes a decimal part will be described. FIG. 5 is an explanatory diagram for describing processing in the pulse generator 101 when the frequency division value of each of TPG, SPG, and FPG includes a decimal part. However, in each of the TPG, SPG, and FPG, the processing in the case where the frequency division value includes a decimal part is the same, and for convenience of description, FIG. 5 will exemplify the case of FPG.

For example, the frequency division value of the FPG is 16.10229
In the case of 8 ..., the integer part is Nf, and the decimal part is ENf. When the frequency divider 200 repeats the frequency division of the system clock by Nf and outputs the FPG, the difference from the true frequency division value is accumulated. Therefore, the pulse Pn divided by the frequency divider 200 is fed back to the MPU 300 (corresponding to the arithmetic control means according to claim 4), and every time the pulse Pn is generated, ENf is added, and this is set as SENf. . When SENf exceeds “1”, MPU 300 outputs a P1 signal as a carry signal. That is,
The P1 signal is normally “0”, but becomes “1” when SENf exceeds “1”. Subsequently, the P1 signal is added to the adder 5
At 01, Nf is added, and the frequency divider 200 divides the system clock by the division value Nf + 1. At this time, the MPU 300 adds ENf-1 to SENf to reduce the accumulated difference. When SENf is equal to or less than "1", the frequency division value is Nf which is an integer part. By repeating this process, it is possible to perform a frequency division process close to the frequency division by the true frequency division value.

In FIG. 5, DTP is a frequency divider 20.
This is data for obtaining the track pulse TP by dividing the frequency of the pulse Pn divided by 0 by the frequency divider 502. In the case of FPG, cb is set as DTP. T
By monitoring P, it is possible to detect that a pulse for one track has been output.

The processing described above is completed in the time required for the turntable 104 to make one rotation. In the case of the CAV method, there is no change in the time required for one turn of the turntable 104 of the next track, so that the currently performed processing is continued. On the other hand, in the case of the CLV method, a linear velocity V (m / s), which is CLV driving data, a driving start position R0 (mm),
Given the track pitch PT (μm), the time T for one rotation of the turntable 104 is T = 2 × π × R0 × 10
00 / (V × 1,000,000). Since the track pitch PT is added to R0 every rotation, the time T of one rotation of the turntable 104 changes. When the time required for one rotation of the turntable 104 changes for each track as in the CLV method, the frequency division value is updated each time.

As described above, according to the optical disk master exposure apparatus of the second embodiment, the rotation / transverse drive signal (TPG / SPG) of the optical disk master 105 and the reference pulse (FPG) of the information signal generator 109 are the same. Of the TPG, SPG, and TPG by dividing the system clock of FIG. 1 and calculating the respective frequency division values based on the time per rotation of the master optical disk 1051 so that frequency division errors do not accumulate. Since the FPG is generated (the processing of the decimal part included in the frequency division value), stable pit position accuracy can be obtained over the entire surface of the optical disk master 105.

[Embodiment 3] The optical disk master exposure apparatus of the embodiment 3 controls the time of one rotation of the optical disk master to increase step by step in a fixed area, and provides a stable MCAV or MCLV format over the entire surface of the optical disk master. It is possible to record information accurately at the pit position.

In the device configuration described in the first and second embodiments, the rotation speed of the turntable 104 is set to, for example, 10
280 rpm, 260 rpm, 240 for every 00 tracks
rmp,... as described in the first and second embodiments, the frequency division value of each of the TPG and SPG is obtained according to the rotation speed of the turntable 104, and
The frequency division value of the SPG is changed step by step for each track. At this time, the frequency division value of the FPG is fixed. Therefore, the number of cb per track increases in proportion to the time of one rotation of the turntable 104. That is, the amount of information recorded per track increases. In this example, 100
It is possible to obtain an optical disk master 105 in which the amount of information recorded per track is increased for every 0 tracks. A method of recording latent image pits on an optical disk master in such a format is called an MCAV or MCLV recording format.

As described above, according to the optical disk master exposure apparatus of the third embodiment, the control is performed so that the time of one rotation of the optical disk master 105 is increased step by step in each fixed area. Stable pit position accuracy can be obtained.

[Fourth Embodiment] The optical disk master exposure apparatus according to the fourth embodiment uses the rotation / lateral feed drive signals (TPG, SPG) of the optical disk master while reviewing the time required for each rotation of the optical disk master. CLV driving is performed, and a reference clock (FPG) of an information signal generator is generated at a frequency division value for keeping the channel bit (cb) per rotation of the optical disk master constant, and pits in a CAV format stable over the entire surface of the optical disk master. Information can be accurately recorded at a position.
That is, in the fourth embodiment, the frequency division values of the FPG, TPG, and SPG are changed in accordance with the time change of one rotation of the turntable 104, and the rotation and lateral feed of the optical disk master 105 are synchronized in synchronization with these. Controls signal generation.

In the optical disk master exposure apparatus having the structure described in the first and second embodiments, the linear velocity V (m / s) as CLV drive data and the drive start position R0 (m
m) and the track pitch PT (μm), the time T of one turn of the turntable 104 can be obtained. Even in the CLV system, one of the turntables 104
If the time per rotation can be obtained, the method described in the first and second embodiments can be applied. C
In the AV system, there is no change in time for each rotation of the turntable 104, but in the CLV system, the turntable 104 does not change.
The rotation time is changed for each rotation of.

From the above CLV data, turntable 1
The rotation time T of 04 is T = 2 × π × R0 × 1000 / (V × 1,000,000) = π × R0 / (V × 500), and the frequency FP is FP = 290000 / T. TP / SP can be similarly obtained. Assuming that the system clock used in this system is 200 MHz, the frequency-divided data is 20000000 / FP. V = 1.2 m / s, R0 = 23 mm, PT = 1.4
Assuming 8 μm, T is 0.120366.
In c), the divided data is 16.602298.

In the second embodiment, as described with reference to FIG. 5, the integer part of the frequency-divided data is Nf and the decimal part is EN.
f. When the frequency division of the system clock is repeated at Nf, the difference from the true frequency division value is accumulated. Therefore, the processing described with reference to FIG. 5 is executed to approach the true frequency division value. DTP for FPG
Is set as cb. By monitoring the TP, it can be seen that a pulse for one track has been output. A desired FPG can be obtained by repeating the same processing from the frequency division value of the next track (fixed in the CAV method, and also changes in the CLV method in order to change the time per turn of the turntable 104). Can be.

The time T required for one turn of the turntable 104 one track ahead (R0 + PT) is as follows: T = 2 × π × (R0 + PT) × 1000 / (V × 1,000,000) = π × (R0 + PT) / (V × 500). The time increment DT is DT = π × PT / (V × 500), and the dividing increment DN is DN = DT × 20000000/2900000 = DT × 20000/29. Each time the TP signal is added, the frequency division increment DN is added to the initial frequency division value to obtain Nf and ENf. By repeating the same processing as described above, even when driving the turntable 104 by the CLV method, cb per track is obtained. An optical disc master having a constant number can be obtained. The resulting optical disc is in CAV format.

As described above, according to the optical disk master exposure apparatus of the fourth embodiment, the time required for each rotation of the optical disk master 105 is reviewed while the optical disk master 10
5 by rotation / transverse drive signal (TPG / SPG)
Since the LV drive is performed and the reference pulse (FPG) of the information signal generator 109 is generated by dividing the number of channel bits (cb) per one rotation of the optical disk master 105, the reference pulse (FPG) is stable over the entire surface of the optical disk master 105. The pit position accuracy of the CAV format described above can be obtained.

In particular, in the optical disk master exposure apparatus described in the first embodiment, the light amount optical modulator 115
And the light quantity modulator driver 116, it is possible to control the light quantity of the exposure laser light applied to the optical disc master 105 to be constant.
05, a stable pit shape can be obtained.

[Fifth Embodiment] The optical disk master exposure apparatus of the fifth embodiment controls the information signal generator so that the number of channel bits (cb) per track of the information signal generator does not change even when the optical disk master is driven by the CLV. , And control so that the number of channel bits (cb) increases step by step in a certain area, so that MCAV or M
Information can be accurately recorded at pit positions in the CLV format.

In the optical disk master recording apparatus described in the fourth embodiment, the number of channel bits (cb) is set to, for example, 290000, 310000, 1000 for every 1000 tracks.
When the frequency is changed to 330000,... As described above, the frequency dividing value of the FPG is obtained every 1000 tracks, and the frequency dividing value of the FPG is changed stepwise. That is, with respect to the time change of one turn of the turntable 104, cb per track (the same as one turn of the turntable 104) is applied.
The FPG is output so that the number does not change, the cb number is increased every 1000 tracks, and the FPG is output so that the 1000 tracks maintain the increased cb number.
As a result, it is possible to obtain an optical disk master in which the amount of information per track increases every 1000 tracks. This is called MCAV or MCLV recording format.

As described above, according to the optical disk master exposure apparatus of the fifth embodiment, the number of channel bits (cb) per track of the information signal generator 109 does not change even when the optical disk master 105 is driven by the CLV. And the channel bits (c
In order to control b) to increase, the master optical disc 1
05, stable pit position accuracy of the MCAV (MCLV) format can be obtained.

[Sixth Embodiment] An optical disk master exposure apparatus according to the sixth embodiment is for obtaining an optical disk master having a format conforming to the DVD-RAM standard. That is, in the optical disk master exposure apparatus of the sixth embodiment,
In the optical disk master exposure apparatus of the fifth embodiment, when the pulse generator 101 increases the number of pulses of the FPG, the pulse generator 101 increases the number of pulses of the FPG in 24 steps and increases the number of pulses by 43152 in each step. It is.

The number of channel bits (cb) (1 of FPG)
The number of clocks output per track) is K3, and cb is gradually changed to K3 + 43152, K3 + 4315.
2 × 2,... The time required for the turntable 104 to make one rotation is: T = 2 × π × R × 1000 / (V × 1,000,000) = 2 × π × R / (V × 1000) Since the frequency of the FPG is given by K3 / T, the radius when cb is K3 is R1, and cb is K3 +
When the radius is 43152, the radius is R2;
T1 = 2 × π × R1 / (V × 1000) T2 = 2 × π × R2 / (V × 1000) T3 = 2 × π × R3 / (V × 1000) ... Therefore, the FPG can be increased stepwise as K3 / T1 (K3 + 43152) / T2 (K3 + 43152) / T3.

As described above, according to the optical disk master exposure apparatus of the sixth embodiment, when increasing the number of pulses of the FPG, the number of pulses of the FPG is increased in 24 steps, and 43152 pulses are added in each step. To increase,
The MCLV format determined by the DVD-RAM standard can be stably realized.

[0088]

As described above, according to the optical disk master exposure apparatus of the present invention (claim 1), a system clock is input, and the system clock is frequency-divided according to the rotation of the glass substrate N (N is an integer). A first pulse for controlling the rotation of the glass substrate, a second pulse for controlling the lateral feed of the glass substrate, and an information signal are calculated by dividing the system clock by the calculated divided value. Control the output of the third
Pulse generating means for outputting a pulse, a rotating means for rotating the glass substrate based on the first pulse, a lateral feeding means for laterally feeding the glass substrate based on the second pulse, and a third pulse Information signal generating means for outputting an information signal recorded on a glass substrate as information latent image pits, laser light output means for outputting an exposure laser beam for irradiating the glass substrate, and Modulating the exposure laser light, and information latent image pit forming means for irradiating the modulated exposure laser light onto the glass substrate,
The calculation time for obtaining the frequency division value can be arbitrarily set, and can be adapted according to the required quality of the pit position accuracy over the entire surface of the glass substrate. Note that the CAV accuracy is irrelevant to N, but as N increases, the CLV accuracy decreases.

Further, according to the optical disk master exposure apparatus of the present invention (claim 2), a system clock is inputted, and the frequency division of the system clock is performed according to 1 / N rotation of the glass substrate (N is an integer). The system clock is frequency-divided by the calculated frequency division value, and the output of the first pulse for controlling the rotation of the glass substrate, the second pulse for controlling the lateral feed of the glass substrate, and the output of the information signal are generated. Pulse generating means for outputting a third pulse to be controlled, rotating means for rotating the glass substrate based on the first pulse, and traversing means for laterally moving the glass substrate based on the second pulse;
Information signal generating means for outputting an information signal recorded on a glass substrate as an information latent image pit based on a third pulse, laser light output means for outputting exposure laser light for irradiating the glass substrate, Modulating the exposure laser light based on the signal, and an information latent image pit forming means for irradiating the modulated exposure laser light onto the glass substrate, the calculation time for obtaining the frequency division value can be arbitrarily set, It is possible to cope with the required quality of the pit position accuracy on the entire surface of the glass substrate. Note that the CAV accuracy is independent of N,
Is increased, the CLV accuracy is improved.

According to the optical disk master exposure apparatus of the present invention, a system clock is input, and a frequency dividing value for dividing the system clock is calculated according to a time required for one rotation of the glass substrate. A first pulse for controlling the rotation of the glass substrate, a second pulse for controlling the lateral feed of the glass substrate, and a third for controlling the output of the information signal by dividing the system clock by the calculated dividing value. Pulse generating means for outputting a pulse; rotating means for rotating the glass substrate based on the first pulse; transverse feeding means for horizontally feeding the glass substrate based on the second pulse; Information signal generating means for outputting an information signal recorded on a glass substrate as an information latent image pit, laser light output means for outputting an exposure laser beam for irradiating the glass substrate, and an information signal Information pit forming means for modulating the exposure laser light based on the exposure laser light onto the glass substrate based on the exposure laser light, so that information can be accurately recorded at a stable pit position over the entire surface of the glass substrate. Can be.

Further, according to the optical disk master exposure apparatus of the present invention (claim 4), in the optical disk master exposure apparatus according to any one of claims 1 to 3, the pulse generating means comprises the first to third optical disks. Calculation control means for calculating a frequency division value for obtaining the first pulse, first frequency division means for dividing the system clock based on the frequency division value and outputting a first pulse, and based on the frequency division value Second frequency dividing means for dividing the system clock and outputting a second pulse, and third frequency dividing means for dividing the system clock based on the divided value and outputting a third pulse. Therefore, information can be accurately recorded at a stable pit position over the entire surface of the glass substrate.

According to the optical disk master exposing apparatus of the present invention, the arithmetic and control means can control the first optical disk every time the first pulse is output. The decimal part included in the frequency division value for obtaining the pulse is added, and when the addition value exceeds 1, a carry signal is output, and the carry signal and the integer part of the frequency division value are added. Since the first pulse is output as a divided value for obtaining the first pulse, the first pulse can be output with high accuracy even when the divided value includes a decimal part. That is, since the first pulse is generated by appropriately changing the frequency division value so as not to cause a frequency division error, information can be accurately recorded at a stable pit position over the entire surface of the glass substrate.

According to the optical disk master exposure apparatus of the present invention (claim 6), in the optical disk master exposure apparatus of claim 4, the arithmetic control means causes the second control unit to output the second pulse every time the second pulse is output. The decimal part included in the frequency division value for obtaining the pulse is added, and when the addition value exceeds 1, a carry signal is output, and the carry signal and the integer part of the frequency division value are added. Since the second pulse is output as a divided value for obtaining the second pulse, the second pulse can be output with high accuracy even when the divided value includes a decimal part. That is, since the frequency division value is appropriately changed so as not to cause a frequency division error and the second pulse is generated, information can be accurately recorded at a stable pit position over the entire surface of the glass substrate.

Further, according to the optical disk master exposure apparatus of the present invention (claim 7), in the optical disk master exposure apparatus of claim 4, the arithmetic and control means causes the third control unit to output the third pulse every time the third pulse is output. The decimal part included in the frequency division value for obtaining the pulse is added, and when the addition value exceeds 1, a carry signal is output, and the carry signal and the integer part of the frequency division value are added. Since the third pulse is output as a divided value for obtaining the third pulse, the third pulse can be output with high accuracy even when the divided value includes a decimal part. That is, since the third pulse is generated by appropriately changing the frequency division value so as not to cause a frequency division error, information can be accurately recorded at a stable pit position over the entire surface of the glass substrate.

According to the optical disk master exposure apparatus of the present invention (claim 8), in the optical disk master exposure apparatus of claim 4, the arithmetic and control means inputs the third pulse, and sets the frequency division value as glass. By dividing the third pulse by using the amount of information recorded on one track of the substrate, it is possible to detect that the third pulse has been output for one track. It is possible to sufficiently cope with a case where the time required for rotation is changed.

According to the optical disk master exposure apparatus of the present invention (claim 9), in the optical disk master exposure apparatus according to any one of claims 1 to 3, the pulse generating means comprises one rotation of the glass substrate. When the time required for the glass substrate is changed in several stages in proportion to the radius of the glass substrate, the frequency of the first pulse for controlling the rotation of the glass substrate according to the change in the time required for one rotation of the glass substrate and the frequency of the glass substrate Since the frequency of the second pulse for controlling the lateral feed is changed, information can be accurately recorded at a stable pit position in the MCAV or MCLV format over the entire optical disk master.

Further, according to the optical disk master exposure apparatus of the present invention (claim 10), in the optical disk master exposure apparatus according to any one of claims 1 to 3, the pulse generating means comprises one rotation of the glass substrate. When changing the time required in proportion to the radial position of each rotation of the glass substrate,
The frequency of the first pulse and the second pulse is changed to make the number of the first and second pulses output within the time required for one rotation of the glass substrate constant, and the frequency of the third pulse is changed Since the number of third pulses output within the time required for one rotation of the glass substrate is kept constant, information can be accurately recorded at stable pit positions in the CAV format over the entire surface of the glass substrate. That is,
Even if the glass substrate is driven by CLV, the number of channel bits (cb) per track is controlled so that it does not change, so that the exposure laser light amount is constant over the entire surface of the glass substrate, and stable CAV format exposure is possible. Becomes

According to the optical disk master exposure apparatus of the present invention (claim 11), in the optical disk master exposure apparatus according to claim 10, the pulse generating means changes the frequency of the third pulse to change the frequency of the glass substrate. In order to increase the number of third pulses output per rotation in several steps, a stable MCAV or M
Information can be accurately recorded at pit positions in the CLV format.

According to the optical disk master exposure apparatus of the present invention, the rotation control means rotates the glass substrate in synchronization with the first pulse. , The traverse means is the second
Since the glass substrate is fed laterally in synchronization with the pulse, the information can be accurately recorded at a stable pit position over the entire surface of the glass substrate.

Further, according to the optical disk master exposure apparatus of the present invention (claim 13), in the optical disk master exposure apparatus of claim 12, the exposure laser light irradiated onto the glass substrate by the information latent image pit forming means is provided. Since the amount of light is constant over the entire exposure region on the glass substrate, it is only necessary to irradiate a constant amount of exposure laser light over the entire surface of the glass substrate, and a glass substrate having a stable pit shape can be generated.

Further, according to the optical disk master exposure apparatus of the present invention, the pulse generating means increases the third pulse number by 24 steps in the optical disk master exposure apparatus of claim 11. In addition, since the third pulse number is increased in each step and the pulse number is increased by 43152 pulses in each stage, a glass substrate having a format conforming to the DVD-RAM standard can be generated.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disk master exposure apparatus according to a first embodiment;

FIG. 2 is a block diagram of a pulse generator used in the optical disk master exposure apparatus of the first embodiment.

FIG. 3 is an explanatory diagram for describing processing in a case where a fractional part is included in each of the frequency division values of TPG, SPG, and FPG in the optical disk master exposure apparatus of the first embodiment.

FIG. 4 is a block diagram of an optical disk master exposure apparatus according to Embodiment 2 of the present invention;

FIG. 5 is an explanatory diagram for explaining processing in a case where a fractional part is included in each of the frequency division values of TPG, SPG, and FPG in the optical disk master exposure apparatus of the second embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Host computer 101 Pulse generator (PG) 102 Spindle motor controller 103 Spindle motor (M1) 104 Turntable 105 Master optical disk 106 Lateral feed motor controller 107 Lateral feed motor (M2) 108 Lateral feed stage 109 Information signal generator (FG) 110 Signal modulator driver 111 Signal optical modulator 112 Ar laser 114 Objective lens 115 Light intensity optical modulator 116 Light intensity modulator driver 117, 118 Encoder 200 First frequency divider 201 Second frequency divider 202 Third Frequency divider 203 system clock generator 300,500 MPU 301,501 adder 302,502 frequency divider 400 modulator driver 401 optical modulator

Claims (14)

[Claims] After a photoresist film is formed on a glass substrate, the photoresist film is irradiated with an exposure laser beam modulated by an information signal while rotating and laterally moving the glass substrate, and information is irradiated on the glass substrate. In an optical disk master exposure apparatus for forming latent image pits, a system clock is input and the glass substrate is rotated N times (N
A first pulse for controlling rotation of the glass substrate by dividing a frequency of the system clock by the calculated divided value to calculate a frequency dividing value for dividing the system clock in accordance with the following formula: Pulse generating means for outputting a second pulse for controlling the lateral feed of the substrate and a third pulse for controlling the output of the information signal; and rotating means for rotating the glass substrate based on the first pulse. Traversing means for traversing the glass substrate based on the second pulse; and outputting the information signal recorded on the glass substrate as the information latent image pit based on the third pulse. Information signal generating means; laser light output means for outputting the exposure laser light for irradiating the glass substrate; modulating the exposure laser light based on the information signal; Optical disc master exposure apparatus comprising: the information latent image pit forming means for irradiating laser light on the glass substrate. 2. After forming a photoresist film on a glass substrate, the photoresist film is irradiated with an exposure laser beam modulated by an information signal while rotating and traversing the glass substrate, so that information is exposed on the glass substrate. In an optical disk master exposure apparatus for forming latent image pits, a system clock is input, and a frequency dividing value for dividing the system clock is calculated according to 1 / N rotation (N is an integer) of the glass substrate. A first method for dividing the system clock by a dividing value to control the rotation of the glass substrate.
Pulse generating means for outputting a second pulse for controlling the lateral feed of the glass substrate and a third pulse for controlling the output of the information signal; and controlling the glass substrate based on the first pulse. Rotating means for rotating; traversing means for traversing the glass substrate based on the second pulse; and the information latent image pits recorded on the glass substrate based on the third pulse. An information signal generating means for outputting an information signal; a laser light output means for outputting the exposure laser light for irradiating the glass substrate; and the exposure laser which modulates the exposure laser light based on the information signal and modulates the exposure laser light. An optical disc master exposure apparatus, comprising: an information latent image pit forming means for irradiating light onto the glass substrate. 3. After forming a photoresist film on a glass substrate, the photoresist film is irradiated with an exposure laser beam modulated by an information signal while rotating and laterally moving the glass substrate, and an information beam is formed on the glass substrate. In an optical disk master exposing apparatus for forming a latent image pit, a system clock is input, a frequency dividing value for dividing the system clock is calculated according to a time required for one rotation of the glass substrate, and the calculated frequency dividing value is calculated. Dividing the system clock to output a first pulse for controlling the rotation of the glass substrate, a second pulse for controlling the lateral feed of the glass substrate, and a third pulse for controlling the output of the information signal Pulse generating means for rotating the glass substrate based on the first pulse; and rotating means for rotating the glass substrate based on the first pulse. Transverse feed means for performing transverse feed; information signal generating means for outputting the information signal recorded on the glass substrate as the information latent image pit based on the third pulse; and irradiating the glass substrate with the information signal. Laser light output means for outputting exposure laser light; information latent image pit forming means for modulating the exposure laser light based on the information signal and irradiating the modulated exposure laser light onto the glass substrate An optical disk master exposure apparatus, characterized in that: 4. The apparatus according to claim 1, wherein said pulse generating means includes:
Calculation control means for calculating a frequency division value for obtaining the pulse of the first frequency; first frequency division means for frequency-dividing the system clock based on the frequency division value and outputting the first pulse; A second frequency divider that divides the system clock based on a frequency value and outputs the second pulse; and a frequency divider that divides the system clock based on the frequency value and generates the third pulse. The optical disk master exposure apparatus according to any one of claims 1 to 3, further comprising third frequency dividing means for outputting. 5. The arithmetic control means adds a decimal part included in a frequency division value for obtaining the first pulse every time the first pulse is output, and the added value exceeds one. Outputting a carry signal, adding the carry signal and an integer part of the divided value, and outputting the result as a divided value for obtaining the first pulse. Item 5. An optical disk master exposure apparatus according to Item 4. 6. The arithmetic control means adds a decimal part included in a frequency division value for obtaining the second pulse every time the second pulse is output, and the added value exceeds one. Outputting a carry signal, adding the carry signal and an integer part of the divided value, and outputting the result as a divided value for obtaining the second pulse. Item 5. An optical disk master exposure apparatus according to Item 4. 7. The arithmetic control means adds a decimal part included in a frequency division value for obtaining the third pulse every time the third pulse is output, and the added value exceeds one. Outputting a carry signal, adding the carry signal and an integer part of the divided value, and outputting the sum as a divided value for obtaining the third pulse. Item 5. An optical disk master exposure apparatus according to Item 4. 8. The arithmetic and control unit receives the third pulse and divides the third pulse using an information amount recorded on one track of the glass substrate as a division value. 5. The optical disk master exposure apparatus according to claim 4, wherein it is detected that the third pulse is output for one track. 9. When the pulse generation means changes the time required for one rotation of the glass substrate in several steps in proportion to the radius of the glass substrate, the change in the time required for one rotation of the glass substrate is determined. The frequency of a first pulse for controlling the rotation of the glass substrate and the frequency of a second pulse for controlling a lateral feed of the glass substrate are changed in response thereto. An optical disk master exposure apparatus according to any one of the above. 10. The first pulse and the second pulse when the pulse generation means changes a time required for one rotation of the glass substrate in proportion to a radial position for each rotation of the glass substrate. Changing the frequency of the pulse and outputting the first signal within the time required for one rotation of the glass substrate;
And setting the second pulse number to a constant number, and changing the frequency of the third pulse to a constant number for the third pulse number output within the time required for one rotation of the glass substrate. The optical disc master disc exposure apparatus according to any one of claims 1 to 3, wherein: 11. The method according to claim 1, wherein the pulse generating means changes the frequency of the third pulse, and increases the number of third pulses output per rotation of the glass substrate in several steps. The optical disk master exposure apparatus according to claim 10. 12. The rotation control means rotates the glass substrate in synchronization with the first pulse, and the traverse means traverses the glass substrate in synchronization with the second pulse. The optical disk master exposure apparatus according to claim 11, wherein: 13. The apparatus according to claim 12, wherein the amount of the exposure laser beam applied to the glass substrate by the information latent image pit forming means is constant over the entire exposure area on the glass substrate. Optical disk master exposure equipment. 14. The pulse generating means increases the third pulse number in 24 steps when increasing the third pulse number, and increases the pulse number by 43152 pulses in each step. The optical disk master exposure apparatus according to claim 11, wherein