JP2006172713A - Optical disk master exposure system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform high-density recording on an optical disk master in a simpler or inexpensive constitution. <P>SOLUTION: This exposure system is provided with a light source 17 which outputs exposure light for irradiating the optical disk master 3 to form a spiral or concentric pit sequence, a first rotating mechanism 14 which rotates the optical disk master 3, and a second rotating mechanism 11 which is arranged by being shifted from a rotation axis of the first rotation mechanism 14, and rotates the exposure light or the optical disk master 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disk master exposure apparatus that forms a spiral or concentric pit array by irradiating an optical disk master with exposure light such as a laser beam or EB (electron beam).

  The outline of optical disc production is as follows. First, a photoresist, which is a photosensitive material, is applied to a glass original plate, and this is used as an optical disc master. Next, the photoresist on the optical disc master is exposed with a laser beam or EB to process the information to be recorded into a concave shape, and this is recorded as a pit signal (pit row). Thereafter, processing such as development is performed on the optical disc master, information is subsequently copied from the optical disc master, and a metal stamper necessary for replicating the optical disc is created using this information as a master. The metal stamper is used for duplication to complete the final product, the optical disc. In the manufacture of such an optical disc, information is recorded by exposing the photoresist of the optical disc master to a laser beam.

  FIG. 24 is a block diagram of such an optical disk master recording apparatus. An optical disk master 3 is disposed on a stage 2 connected to the spindle motor 1. This optical disc master 3 is obtained by applying a photoresist as a photosensitive material on a glass master. On the other hand, a uniaxial slider 4 is disposed above the stage 2, and an exposure optical head (exposure laser head) 5 is attached to the moving end. The exposure optical head 5 irradiates the optical disc master 3 with a laser beam output from the exposure optical system 6. The uniaxial slider 4 is movable in the radial direction of the optical disc master 3 at the moving end to which the exposure optical head 5 is attached, that is, a linear guide driving method. The computer 7 controls the rotation of the spindle motor 1, controls the movement of the uniaxial slider 4, and controls the laser beam output of the exposure optical system 6.

  With such a configuration, the optical disc master 3 is rotated by the rotation of the spindle motor 1, and in this state, the exposure optical head 5 is slid in the uniaxial direction, that is, in the radial direction of the optical disc master 3. As shown in FIG. 25, the exposure optical head 5 performs recording by linearly sliding from the position of the outermost recording radius R to the position of the innermost recording radius r on the optical disc master 3 (linear guide method). ). At this time, the sequence of digital signals to be recorded and the slide movement direction are orthogonal. As a result, the laser beam emitted from the exposure optical head 5 is irradiated onto the optical disc master 3 coated with the rotating resist. At this time, when the irradiation of the laser beam is controlled according to the information, the optical disc master 3 On the top, information groups such as pits and grooves are recorded.

  At this time, the position of the exposure optical head 5 is measured by the laser interferometer 4a, and is always subjected to feedback control by a fine movement system (not shown). Accordingly, the resolution of the track pitch by such an exposure apparatus is uniquely determined by the measurement resolution of the laser interferometer 4a. Further, in such a drive system that linearly scans the exposure optical head 5, the uniaxial slider 4 and the like must be made highly rigid. For this purpose, the uniaxial slider 4 uses, for example, a two-guide type slider. Become. For this reason, such a slider is configured to straddle the optical disc master 3, so that the entire apparatus is increased in weight and size.

On the other hand, as a driving method of the exposure optical head 5, there is a method in which a swing arm method which is found in a magnetic recording method of an HDD (Hard Disk Drive) is applied in addition to a linear guide method of linear scanning. The drive by the swing arm method is to move the exposure optical head 5 in an arc shape from the position of the outermost recording radius R to the position of the innermost recording radius r as shown in FIG.
In such a system, since the rotational center position of the swing arm is outside the optical disc master 3, the drive locus of the exposure optical head 5 has a curvature. It has become.

  The position of such a swing arm type exposure optical head is grasped by an encoder provided on a rotation shaft that drives the rotation center of the drive locus. Therefore, the limit of the resolution of the track pitch in the swing arm method is determined by the resolution of the encoder. When recording more information on the optical disc than it is currently, it is difficult to increase the amount of information other than reducing the width of adjacent pit rows. The distance between adjacent pit rows is shorter than the length of one pit. In order to perform such high-density recording, it is required to perform positioning in the radial direction with high accuracy when forming each pit.

  In the current exposure apparatus, the motion error when moving the exposure optical head directly appears as uneven track pitch, so this motion error must be made as small as possible. In order to satisfy this requirement, it is one method to increase the resolution of the position detector used in the exposure apparatus, but the position resolution of the encoder and laser interferometer is sluggish and expensive, It is strongly desired to increase the resolution of the exposure apparatus in such a manner that does not depend on the resolution of the position detector.

  In each of the above driving methods, the position of the exposure optical head 5 or the table (or slider) on which the optical head is mounted is controlled using a linear encoder or a laser interferometer, but the position is essentially controlled. The target to be focused is a focused spot of a laser beam that actually exposes and records the resist, and the focused spot position is not directly observed or measured.

With the conventional linear guide system and swing arm system drive, a feed error occurs depending on the resolution of the position detector used, resulting in uneven track pitch. Is difficult.

  Accordingly, an object of the present invention is to provide an optical disc master exposure apparatus that can perform high-density recording on an optical disc master with a simpler or cheaper configuration.

  An optical disc master exposure apparatus according to a main aspect of the present invention includes a light source that outputs exposure light that irradiates an optical disc master to form spiral or concentric pit rows, and a first rotation mechanism that rotates the optical disc master. And a second rotation mechanism that is offset from the rotation axis of the first rotation mechanism and rotates the exposure light or the optical disc master.

  According to the present invention, it is possible to provide an optical disc master exposure apparatus that can perform high-density recording on an optical disc master with a simpler or less expensive configuration.

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
In the optical disk master exposure method of the present invention, as shown in FIG. 1, the optical disk master 3 is irradiated with exposure light, for example, a laser beam, and a spiral or concentric pit row p is formed on the optical disk master 3. The laser beam irradiation is performed so as to have a trajectory parallel to or oblique to the pit row p (driving trajectory F of the exposure optical head). Such a laser beam irradiation locus is preferably in contact with at least one point of the pit row p, for example, the point A or B in the locus shown in FIG. That is, the laser beam irradiation may be performed so as to be a trajectory in contact with the innermost pit row p on the optical disc master 3 at the point B.

  Further, the laser beam irradiation may be performed so as to be a locus in contact with the outermost pit row p on the optical disc master 3 at the point A. Irradiation of the laser beam to the optical disc master 3 is performed so as to form an arc locus centered on the point S. The locus of the laser beam, which is the locus of the arc, is the radius of the innermost pit row p (innermost recording radius) r and the radius of the outermost pit row p (outermost recording radius) R of the optical disc master 3. And the center point S of the locus of the laser beam is in the plane of the optical disc master 3.

  Therefore, the optical disc master exposure method according to the first embodiment of the present invention rotates the optical disc master 3 at a predetermined speed, inscribes the exposure optical head to the outermost recording radius R of the optical disc master 3, and the innermost circumference. Information is recorded by circumventing the recording radius r and moving it onto a drive locus F having a diameter of (R + r) and irradiating the optical disc master 3 with a laser beam to form a pit row.

  In such a driving locus F of the exposure optical head, for example, when the outermost recording radius R is 60 mm and the innermost recording radius r is 20 mm, the length of the driving locus is 125.6 mm.

Here, the length of the drive locus by the conventional rear guide method shown in FIG. 25 is 40 mm, and the length of the drive locus F of the present invention is 3.14 times longer than each of the conventional methods. Become.

Therefore, when the encoder and the distance measuring instrument used in the conventional apparatus are used as they are, the resolution is apparently 3.14 times as much as the track direction (pit row direction) (the error is reduced to 1 / 3.14). ) Is obtained, and high resolution can be achieved by realizing high resolution at the time of information recording on the optical disc master 3.
In addition, if the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.
In an actual disc, the diameter is 80 mm or 120 mm, so the actual resolution is further increased.
As shown in FIG. 2A, the arc-shaped laser beam trajectory F intersects these track directions at an angle α when focusing on, for example, the nth track to the (n + 1) th track on the optical disc master 3, so The length of the trajectory becomes longer than the driving trajectory by the Lier guide method shown in FIG. 2B. As a result, the sensitivity is reduced at 1 / cos (90 ° −α) in the case of the locus F of the arc-shaped laser beam.

FIG. 3 shows the relationship of the angle α intersecting the track pitch of the trajectory F with respect to the scanning angle θ (= 0 ° to 180 °) of the trajectory F of the arc-shaped laser beam shown in FIG. The angle α intersecting at θ (= 120 °) indicates 30 °.
Therefore, since the crossing angle α becomes a curved curve with α = 30 ° as a curvature value, the distance between the tracks of the locus F of the laser beam is increased accordingly, and for example, uneven feeding of the feeding system occurs. However, the influence on this can be reduced.

  FIG. 5 is a diagram comparing the sensitivity of the arc-shaped laser beam locus F with the sensitivity of the prior art (linear guide method). The sensitivity of the arc-shaped laser beam when the sensitivity of the prior art is “1”. The sensitivity by the locus F is shown. That is, even at the scanning angle θ (= 120 °), the sensitivity due to the locus F of the laser beam is twice that of the prior art, and before and after that, it is higher than the sensitivity at the scanning angle θ (= 120 °). Therefore, according to the present invention, high-resolution recording can be realized by realizing high resolution at the time of information recording on the optical disc master 3.

  When the exposure / recording on the optical disc master 3 is completed in this way, thereafter processing such as development on the optical disc master 3 is performed, and then information is copied from the optical disc master 3, and the optical disc is duplicated using this as a master disc. The metal stamper necessary for the production is created. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, according to the first embodiment, the laser beam is irradiated with an arc trajectory whose diameter is the sum of the radius r of the innermost pit row and the radius R of the outermost pit row in the optical disc master 3. Therefore, there is no uneven track pitch and information can be recorded with high density. Further, in the case of an optical disk replicated using such an optical disk master 3, high-density information that could not be realized conventionally is recorded.

  Further, since the center S of the arc that becomes the locus of the laser beam is arranged inside the optical disc master 3, the length of the swing arm that moves the laser beam in an arc shape can be shortened, and the laser beam is irradiated. This is optimal for high-density information recording on the optical disc master 3.

Whether the guide is a linear guide or a swing arm, the longer the distance from the supporting point that supports them to the exposure optical head, the greater the applied vibration will cause a greater positional variation of the exposure optical head. .
Since this fluctuation is a rotational movement, it is a factor that fluctuates the spot size of the exposure light, and also gives an error in the track pitch direction.
When the support point exists outside the disk, there is always a predetermined distance between the support point and the exposure optical head, but the exposure method according to the present embodiment can be performed by placing the support point inside the disk. It can be used and the error due to the rotational movement can be reduced.

  The present invention is not limited to the optical disk master exposure method of the first embodiment, and may be a laser beam locus as follows. For example, as shown in FIG. 6, the laser beam irradiation may be in contact with the innermost pit row in the optical disc master 3 and become linear trajectories Fa and Fb. The locus Fb is in contact with the innermost pit row at a right angle in the direction from the center. At this time, a conventional linear guide type mechanical unit can be used and high-density recording can be achieved.

Further, the laser beam irradiation trajectory may be in contact with at least one place in the pit row p, and may be an arc in contact with a point A or C as shown in FIG. Even in this case, recording can be performed with a resolution close to that of the first embodiment.
Further, as shown in the figure, the object of the present invention can also be achieved by a spiral trajectory in contact with points A and D, a spiral shape as close as possible to the pit row p, or a concentric circle shape, or a trajectory by an ellipse or a free curve. can do.

(2) Next, a second embodiment of the present invention will be described.

FIG. 8 is a block diagram of an optical disc master exposure apparatus to which the optical disc master exposure method is applied. The surface plate 10 for suppressing vibration is provided with a first motor 11 as a second rotating mechanism. A turntable 12 is coupled to the rotation shaft of the first motor 11, and a second motor as a first rotation mechanism is disposed via a fixing member 13 at a position off the rotation shaft 11 a on the turntable 12. 14 is provided.
A turntable 15 is connected to the rotation shaft of the second motor 14, and the optical disc master 3 is placed on the turntable 15.

Since the second motor 14 for rotating the optical disc master 3 is provided so as to deviate from the rotational axis of the first motor 11 in this way, the line through which the rotational shaft 11a of the first motor 11 passes through the optical disc master 3 is provided. It will be placed on top. That is, the rotation shaft 11a of the first motor 11 coincides with the center S of the drive locus F shown in FIG.
A balancer 19a having the same weight as that of the second motor 14 is provided at a symmetrical position with respect to the rotation shaft 11a of the second motor 14. A lens mount 19b is provided on the optical path of the laser beam, and an imaging lens 19c is attached to the lens mount 19b.

  On the other hand, a laser oscillator 17 as an exposure light source is provided on the surface plate 10 via a support arm 16. A mirror 18 is disposed on the optical path of the laser beam output from the laser oscillator 17, and reflects the laser beam toward the optical disc master 3.

Next, the operation of the apparatus configured as described above will be described.
In the production of an optical disk, first, a photoresist, which is a photosensitive material, is applied to a glass original plate, and this is used as an optical disc master 3. Next, this optical disc master 3 is exposed with a laser beam, information to be recorded is processed into a concave shape, and this is recorded as a pit signal. That is, exposure and recording on the optical disc master 3 are performed as follows.

The optical disc master 3 is placed on the table 15 and rotates at a predetermined speed by driving the second motor 14. At the same time, the first motor 11 rotates at a speed slower than the speed of the second motor 14.
On the other hand, when a laser beam is output from the laser oscillator 17, the laser beam is reflected by the mirror 18 and is incident on the optical disc master 3. As a result, the laser beam contacts the locus F shown in FIG. 1 on the optical disc master 3, that is, the innermost pit row p on the optical disc master 3 at the point B and the outermost pit row p. Irradiation is performed so as to form a circular arc locus that touches the point A and has the center S.

  When the exposure / recording on the optical disc master 3 is completed in this way, thereafter processing such as development on the optical disc master 3 is performed, and then information is copied from the optical disc master 3, and the optical disc is duplicated using this as a master disc. The metal stamper necessary for the production is created. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, according to the second embodiment, since the exposure light is irradiated so as to have a locus parallel or oblique to the pit row p, there is no uneven track pitch and information is recorded at a high density. If it is an optical disc that can be replicated using this optical disc master 3, information is recorded at a high density. In addition, since the center S of the arc that becomes the trajectory of the exposure light is arranged inside the optical disc master 3, it is possible to reduce a shake when the exposure light is irradiated, and a high density to the optical disc master 3. Ideal for information recording.

(3) Next, a third embodiment of the present invention will be described.
FIG. 9 is a block diagram of an optical disc master exposure apparatus to which the above optical disc master exposure method is applied. On the surface plate 20, a two-layer structure is provided in which a base plate 22 is provided via a support 21. A turntable 23 is provided on the surface plate 20, and the optical disc master 3 is placed on the turntable 23. On the base plate 22, a laser oscillator 24 as an exposure light source for the optical disc master 3 is provided. The laser oscillator 24 outputs a laser beam in the same direction as the surface direction of the optical disc master 3. An optical system 24a for narrowing the laser beam on the surface of the optical disc master 3 is disposed on the optical path of the laser beam.

  A first mirror 25 as a front mirror is provided on the base plate 22. The first mirror 25 is disposed on the optical path of the laser beam output from the laser oscillator 24 and on a line passing through the center of the optical disc master 3 and perpendicular to the surface of the optical disc master 3. The first mirror 25 is disposed so as to be a reflection surface having an angle of 45 ° with respect to the surface of the optical disc master 3, and the laser beam output from the laser oscillator 24 is perpendicular to the surface of the optical disc master 3. The incident light is reflected toward the center of the optical disc master 3 in the direction. A mirror raising / lowering mechanism 26 is provided in the incident direction of the laser beam by the first mirror 25.

  The mirror raising / lowering mechanism 26 holds a second mirror 27 as a front mirror, and guides and raises the second mirror 27 in a direction perpendicular to the surface of the optical disc master 3, and the guide body. An elevating motor (not shown) for elevating the second mirror 27 along 28 is provided. The mirror raising / lowering mechanism 26 includes a rotation motor 29 having a second mirror 27 attached to a rotation shaft. The rotation motor 29 rotates the second mirror 27 about the direction perpendicular to the surface of the optical disc master 3 as a rotation axis. The rotary motor 29 moves up and down integrally with the second mirror 27 by driving the lifting motor.

This mirror raising / lowering mechanism 26 drives the raising / lowering motor and the rotary motor 29 in synchronization, and the second mirror 27 rotates, for example, from the upper side to the lower side by the driving of the raising / lowering motor and the rotary motor 29. While descending.

  The second mirror 27 is disposed so as to be a reflection surface at an angle of 45 ° with respect to the optical path of the laser beam reflected from the first mirror 25, and the laser beam is parallel to the surface direction of the optical disc master 3. Reflected in the direction.

  A truncated conical mirror 30 is provided on the lower surface of the base plate 22 as a third mirror. The conical mirror 30 has a mirror surface arranged in a direction at an angle of 45 ° with respect to the surface of the optical disc master 3 from a predetermined position on a vertical line passing through the center position of the optical disc master 3. The conical mirror 30 reflects the laser beam from the second mirror 27 and irradiates the surface of the optical disc master 3 perpendicularly.

  The rotation control unit 30a has a function of controlling the rotation of the mirror lifting mechanism 26 and the rotation motor 29. In particular, the locus of the laser beam irradiated on the surface of the optical disc master 3 is, for example, as shown in FIG. Mirror lift mechanism 26 so as to be in contact with point B on the innermost pit row p in FIG. And the rotation motor 29 are controlled to rotate.

Alternatively, in the case where exposure is performed without rotating the optical disc master in a fixed state, the mirror elevating mechanism 26 and the rotary motor 29 are drawn so that the locus of the laser beam is drawn concentrically or spirally along the desired pit row. It has a function to control the interlocking.

Next, the operation of the apparatus configured as described above will be described.
The optical disc master 3 is placed on the rotary table 23. On the other hand, when a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first mirror 25 and is incident on the center position of the optical disc master 3. Further, this laser beam is reflected in the 45 ° direction by the second mirror 27, travels to the conical mirror 30, is reflected in the 45 ° direction by the conical mirror 30, and is perpendicular to the surface of the optical disc master 3. Irradiated in the direction.

At this time, the mirror raising / lowering mechanism 26 and the rotation motor 29 are rotationally controlled by the rotation control unit 30a, so that the laser beam is reflected by the second mirror 27 and the conical mirror 30 and irradiated onto the surface of the optical disc master 3. 1 is in contact with the innermost pit row p of the optical disc master 3 at the point B and the outermost pit row p at the point A and has a center S as shown in FIG. It becomes a trajectory.
When the exposure / recording on the optical disc master 3 is completed in this way, thereafter, the optical disc master 3 is duplicated as described above, and the final product, the optical disc, is completed.

  On the other hand, such an apparatus can perform exposure and recording as follows. The optical disc master 3 is placed on the fixed table 23. On the other hand, when a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first mirror 25 and is incident on the center position of the optical disc master 3. Further, the laser beam is reflected by the second mirror 27 in the 45 ° direction, travels to the conical mirror 30, is reflected by the conical mirror 30 in the 45 ° direction, and is perpendicular to the surface of the optical disc master 3. Irradiated in the direction. At this time, the second mirror 27 rotates at a constant speed with a vertical line passing through the center position of the optical disc master 3 as a rotation axis by driving of the rotary motor 29, and together with this, from the top of the optical disc master 3 downward It descends at a predetermined speed.

Accordingly, the laser beam reflected by the second mirror 27 and further reflected by the conical mirror 30 and applied to the optical disc master 3 is from the position of the innermost recording radius r of the optical disc master 3 shown in FIG. The entire area up to the position of the outermost recording radius R is scanned over the entire 360 ° circumference.
When the exposure / recording on the optical disc master 3 is completed in this way, thereafter, the optical disc master 3 is duplicated as described above, and the final product, the optical disc, is completed.

  As described above, in the third embodiment, the mirror raising / lowering mechanism 26 and the rotary motor 29 are rotationally controlled to rotate and move the second mirror 27 so that the laser beam irradiation is parallel to the pit row p or Since it is performed so as to have an oblique trajectory, there is no uneven track pitch, information can be recorded at high density, and information can be recorded at high density if it is an optical disk replicated using this optical disk master 3 It becomes. In addition, since the first and second mirrors 25 and 27 and the conical mirror 30 are arranged and the second mirror 27 is moved up and down while rotating, the drive portion can be reduced in weight and the optical disc master 3 As a result, it is possible to eliminate the asynchronous vibration caused by the deviation of the center of gravity between the optical disc master 3 and the spindle motor as in the case of using the spindle motor, and the optical disc master 3 and the spindle. A centering mechanism with the motor can be eliminated.

  In addition, since the center S of the arc serving as the trajectory of the exposure light is arranged inside the optical disc master 3, the exposure light path can be shortened, the shake when the exposure light is irradiated can be reduced, and the optical disc master 3 can be reduced. Ideal for high-density information recording.

  Therefore, the optical disc master 3 subjected to the exposure / recording process has no track pitch unevenness, and information is recorded with high density. If the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

(4) Next, a fourth embodiment of the present invention will be described. The same parts as those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 10 is a block diagram of an optical disc master exposure apparatus to which the optical disc master exposure method is applied. A concave first toroidal mirror 31 is arranged as the first mirror. The first toroidal mirror 31 is formed on a mirror surface having a predetermined curvature, and narrows the short radius side. In addition, a concave second toroidal mirror 32 is disposed as the second mirror. The first toroidal mirror 32 is formed on a mirror surface having a predetermined curvature, and narrows the short radius side. These first and second toroidal mirrors 31 and 32 narrow down the laser beam spot of the laser beam output from the laser oscillator 24 and irradiate the surface of the optical disc master 3 as shown in FIG.

  With such a configuration, exposure and recording on the optical disc master 3 are performed as follows. The optical disc master 3 is placed on the rotary table 23 and rotated at a predetermined speed. When a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first toroidal mirror 31 and is reflected toward the center position of the optical disc master 3, and then the second toroidal mirror 32 has an angle of 45. The light is reflected in the direction of °, further reflected by the conical mirror 30 in the direction of 45 °, and irradiated in the direction perpendicular to the surface of the optical disc master 3.

  At this time, the mirror raising / lowering mechanism 26 and the rotation motor 29 are rotationally controlled by the rotation control unit 30a, so that the laser beam reflected by the second toroidal mirror 32 and the conical mirror 30 and irradiated onto the surface of the optical disc master 3 is irradiated. As shown in FIG. 1, the locus of the beam is an arc that touches the innermost pit row p on the optical disc master 3 at point B, touches the outermost pit row p at point A, and has a center S. The trajectory.

Further, the laser beams reflected by the first and second toroidal mirrors 31 and 32 are focused on the surface of the optical disc master 3 as shown in FIG.
When the exposure / recording on the optical disc master 3 is completed in this way, thereafter, the optical disc master 3 is duplicated as described above, and the final product, the optical disc, is completed.

  On the other hand, such an apparatus can perform exposure and recording as follows. The optical disc master 3 is placed on the rotary table 23. In this case, the rotary table 23 is fixed without rotating. When a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first toroidal mirror 31 and is reflected toward the center position of the optical disc master 3, and then the second toroidal mirror 32 has an angle of 45. The light is reflected in the direction of °, further reflected by the conical mirror 30 in the direction of 45 °, and irradiated in the direction perpendicular to the surface of the optical disc master 3.

  At this time, the second toroidal mirror 32 rotates at a constant speed with a vertical line passing through the center position of the optical disc master 3 driven by the rotation motor 29 as a rotation axis, and at the same time, when viewed from the surface of the optical disc master 3, the second toroidal mirror 32 It descends at a predetermined speed toward Thereby, the locus of the laser beam is drawn concentrically or spirally over the entire disk surface.

  Accordingly, the laser beam applied to the optical disc master 3 is scanned over the entire 360 ° circumference with respect to the entire area from the position of the innermost recording radius r to the position of the outermost recording radius R of the optical disc master 3. The

  At this time, the laser beams reflected by the first and second toroidal mirrors 31 and 32 are focused on the surface of the optical disc master 3 after the laser beam spot is narrowed down.

As described above, in the fourth embodiment, the first and second toroidal mirrors 31 and 32 are formed on mirror surfaces having predetermined curvatures, respectively, and the laser beam spot of the laser beam is narrowed down so that the optical disc master 3 In addition to the same effects as the effects of the third embodiment, the recording of information on the optical disc master 3 can be further densified.
If the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

(5) Next, a fifth embodiment of the present invention will be described. The same parts as those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 12 is a block diagram of an optical disc master exposure apparatus to which the optical disc master exposure method is applied. The 1st mirror 33 with a correction | amendment is arrange | positioned as a 1st mirror. The first correction mirror 33 is configured to be able to change and control the curvature of the mirror surface to correct the lens action on the mirror surface. A second correction mirror 34 is disposed as a second mirror. Similar to the first correction mirror 33, the second correction mirror 34 is configured to be able to change and control the curvature of the mirror surface to correct the lens action on the mirror surface.

  These first and second corrector mirrors 33 and 34 are provided with mirror surfaces 33a and 34a on the back surface of the notch hinge 35 as shown in the external view of FIG. 13A, and on the notch side as shown in FIG. 13B. Two piezoelectric element groups 36 and 37 are provided between the notch ends having different intervals. Each piezoelectric element group 36, 37 is formed by laminating a plurality of piezoelectric elements.

  On the other hand, the curved surface control unit 38 controls the applied voltages to the piezoelectric element groups 36 and 37, respectively, and controls the curvature of one or both of the first and second corrected mirrors 33 and 34. And has a function of correcting the lens action on the mirror surface. That is, the curved surface control unit 38 has a table of voltages applied to the piezoelectric element groups 36 and 37 corresponding to the raising / lowering positions of the second correction mirror 34, and the second correction mirror is obtained from this table. 34 has a function of reading out an applied voltage corresponding to the lift position 34 and applying it to each of the piezoelectric element groups 36 and 37.

With such a configuration, exposure and recording on the optical disc master 3 are performed as follows. The optical disc master 3 is placed on the rotary table 23 and rotated at a predetermined speed. When a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first correction mirror 33 and is incident on the center position of the optical disc master 3.
Subsequently, the laser beam is reflected by the second correction mirror 34 in the direction of 45 °, and further reflected by the conical mirror 30 in the direction of 45 °, and is irradiated in the direction perpendicular to the surface of the optical disc master 3.

  At this time, the mirror raising / lowering mechanism 26 and the rotation motor 29 are rotationally controlled by the rotation control unit 30 a, so that they are reflected by the second correction mirror 34 and the conical mirror 30 and irradiated onto the surface of the optical disc master 3. As shown in FIG. 1, the locus of the laser beam is in contact with the innermost pit row p on the optical disc master 3 at the point B, is in contact with the outermost pit row p at the point A, and has a center S. It becomes the locus of an arc.

The first and second correction mirrors 33 and 34 are controlled in voltage applied to the first or second piezoelectric element group 36 and 37 by the curved surface control unit 38, and the minor radii of the mirror surfaces 33a and 34a are controlled. The side curvature radius is controlled. That is, the radii of curvature of the first and second corrective mirrors 33 and 34 are set according to the ascending / descending position of the second correctable mirror 34 and correct the lens action of the mirrors 33 and 34.
Therefore, the condensing characteristic of the laser beam applied to the optical disc master 3 is optimally set on the optical disc master 3.
When the exposure / recording on the optical disc master 3 is completed in this way, thereafter, the optical disc master 3 is duplicated as described above, and the final product, the optical disc, is completed.

  On the other hand, such an apparatus can perform exposure and recording as follows. The optical disc master 3 is placed on the rotary table 23. In this case, the rotating mirror 23 is fixed without rotating. When a laser beam is output from the laser oscillator 24, the laser beam is reflected by the first correction mirror 33 and is incident on the center position of the optical disc master 3. Subsequently, the laser beam is reflected by the second correction mirror 34 in the direction of 45 °, and further reflected by the conical mirror 30 in the direction of 45 °, and is irradiated in the direction perpendicular to the surface of the optical disc master 3.

At this time, the second mirror 34 with correction rotates at a constant speed with a vertical line passing through the center position of the optical disc master 3 as a rotation axis by driving of the rotary motor 29, and together with this, for example, upward from the surface of the optical disc master 3. Descends at a predetermined speed downward.
Accordingly, the laser beam applied to the optical disc master 3 is scanned over the entire 360 ° circumference with respect to the entire area from the position of the innermost recording radius r to the position of the outermost recording radius R of the optical disc master 3. The Here, in the first and second correction mirrors 33 and 34, as described above, the applied voltage to the first or second piezoelectric element group 36 and 37 is controlled by the curved surface control unit 38, and each mirror surface 33a thereof is controlled. 34a, the radius of curvature on the short radius side is controlled. That is, the radii of curvature of the first and second corrective mirrors 33 and 34 are set according to the ascending / descending position of the second correctable mirror 34 and correct the lens action of the mirrors 33 and 34.
Therefore, the condensing characteristic of the laser beam applied to the optical disc master 3 is optimally set on the optical disc master 3.

  As described above, in the fifth embodiment, since the first and second correction mirrors 33 and 34 are respectively controlled to have predetermined curvatures, the same effects as those of the second embodiment are obtained. In addition to the effects, it is possible to optimally set the condensing characteristic with respect to the optical disc master 3, and to further increase the recording density of information on the optical disc master 3. In addition, if the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

(6) Next, a sixth embodiment of the present invention will be described.

  14 and 15 are configuration diagrams of an optical disc master exposure apparatus to which the above-described optical disc master exposure method is applied. FIG. 14 is a configuration diagram viewed from above, and FIG. 15 is a configuration diagram viewed from the side. The master disk suction disk 40 is for vacuum-sucking and fixing the optical disk master disk 3 placed on the upper surface. An XY drive mechanism 41 is provided above the master disk suction disk 40. In other words, the two X-axis guides 42 and 43 are arranged in parallel to each other with a longer interval than the diameter of the optical disc master 3. These X-axis guides 42 and 43 are provided with X-axis sliders 44 and 45 movably, respectively. Two Y-axis guides 46 and 47 are laid in parallel between the X-axis sliders 44 and 45. The X-axis guides 42 and 43 and the Y-axis guides 46 and 47 are perpendicular to each other.

  An XY stage 48 is movably provided on these Y axis guides 46 and 47. An exposure optical head 49 is mounted on the XY stage 48. The exposure optical head 49 includes a focus actuator in the objective lens so that the focused spot is always just focused with respect to the optical disc master 3.

  The optical system for guiding the laser beam to the exposure optical head 49 is as follows. The laser oscillator 50 is arranged so as to output a laser beam in the X-axis direction. A 45 ° mirror 51 is disposed on the X-axis slider 45 on the optical path of the laser beam output from the laser oscillator 50. The 45 ° mirror 51 reflects the laser beam output from the laser oscillator 50 in the Y-axis direction. Further, a 45 ° mirror 52 for epi-illumination is arranged on the XY stage 48 that is on the reflected laser beam path. The incident 45 ° mirror 52 reflects the laser beam toward the exposure optical head 49.

  On the other hand, the drive control unit 53 issues drive control signals to the X-axis sliders 44 and 45 and the XY stage 48, drives the XY stage 48 by managing XY coordinates, and moves the exposure optical head 49 above the optical disc master 3. , For example, the locus of the laser beam applied to the surface of the optical disc master 3 is in contact with the innermost pit row p on the optical disc master 3 at point B and the outermost pit row p as shown in FIG. Is controlled so as to be a circular arc trajectory that is in contact with a point A and has a center S.

Next, the operation of the apparatus configured as described above will be described.
In manufacturing an optical disc, first, a photoresist, which is a photosensitive material, is applied to a glass original plate, which is used as an optical disc master 3. Next, this optical disc master 3 is exposed with a laser beam, information to be recorded is processed into a concave shape, and this is recorded as a pit signal. That is, exposure and recording on the optical disc master 3 are performed as follows.

  The drive control unit 53 converts the position of each recording pit to be recorded on the optical disc master 3 into XY coordinates, and moves the XY stage 48 according to the XY coordinates. The XY stage 48 is moved by X-axis guides 42 and 43 and Y-axis guides 46 and 47 driven in accordance with a drive control signal, whereby the exposure optical head 49 is moved above the optical disc master 3 on which each recording pit is to be recorded. Position continuously. Or feed control is performed continuously. That is, when the optical disc master is rotated, the exposure optical head 49 is in contact with the innermost pit row p on the optical disc master 3 at the point B and the outermost pit row p as shown in FIG. Positioning or feeding control is continuously performed so that the locus of the laser beam is a circular arc with a point A and a center S.

When the exposure optical head 49 is positioned corresponding to each recording position, a laser beam is output from the laser oscillator 50. This laser beam is reflected by the 45 ° mirror 51 in the Y-axis direction, and then incident on the exposure optical head 49 by the incident 45 ° mirror 52. The exposure optical head 49 irradiates the optical disk master 3 with a focused spot of a laser beam with just focus. Accordingly, since the exposure optical head 49 is positioned above all the recording pits to be recorded on the optical disc master 3 by the movement of the XY stage 48, information is recorded over the entire circumference of the optical disc master 3.

  On the other hand, when the optical disc master 3 is placed on a fixed table, the XY stage 48 is moved so as to draw the locus of the laser beam concentrically or spirally along a desired pit row. Alternatively, the exposure can also be performed by a method in which the entire surface of the master is raster scanned from one side to the opposite side.

  When the exposure / recording on the optical disc master 3 is completed in this manner, information is copied from the optical disc master 3 and a metal stamper necessary for replicating the optical disc is created using this information. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, in the sixth embodiment, since the exposure optical head 49 is positioned and managed by the XY coordinates and is continuously positioned or fed, the same effect as in the second embodiment is achieved. The recording of information on the optical disc master 3 can be performed at a high density, and if the optical disc is replicated using such an optical disc master 3, the information is recorded at a high density.

(7) Next, a seventh embodiment of the present invention will be described.
FIG. 16 is a block diagram showing an optical disc master exposure apparatus to which the optical disc master exposure method is applied. The surface plate 60 is provided with a spindle motor 61 as a rotation mechanism. A turntable 62 is attached to the rotation shaft of the spindle motor 61. The turntable 62 is formed with a suction surface, and vacuum-sucks and fixes the optical disk master 3 to be placed.

  On the other hand, a base plate 63 is provided above the surface plate 60. A laser oscillator 64 that outputs a laser beam as exposure light is provided on the upper surface of the base plate 63. A first mirror 65 is provided on the optical path of the laser beam output from the laser oscillator 64 so as to project the laser beam in a direction perpendicular to the surface of the optical disc master 3. The first mirror 65 is disposed at an angle of 45 ° with respect to the laser beam optical path. A hollow motor 66 is attached to the lower surface of the base plate 63 with the laser beam optical path reflected by the first mirror 65 as the rotation axis.

  This hollow motor 66 has a function as an arc moving means, and is formed with a hollow portion 67 through which the laser beam reflected by the first mirror 65 passes, and the rotating body 68 at the circumferential portion has a rotation axis. It is designed to rotate around the center. An exposure optical head 69 is provided on the lower surface of the hollow motor 66.

  The exposure optical head 69 includes a second mirror 70, a third mirror 71, and an objective lens 72. Of these, the second mirror 70 has a mirror surface disposed at an angle of 45 ° with respect to the surface of the optical disc master 3, and reflects the laser beam reflected by the first mirror 65 in the horizontal direction with respect to the disc. Is. The third mirror 71 is disposed with respect to the second mirror 70 at a distance of one half of the total distance of the outermost recording radius R and the innermost recording radius r in the optical disc master 3. The third mirror 71 has a mirror surface disposed at an angle of 45 ° with respect to the surface of the optical disc master 3, and reflects the laser beam reflected by the second mirror 70 toward the optical disc master 3. It is.

  The objective lens 72 is disposed on the optical path of the reflected laser beam of the third mirror 71 and includes a focus actuator. The objective lens 72 always irradiates the optical disc master 3 with the laser beam to the optical disc master 3 as a focused light focusing spot. Is. Here, when the hollow motor 66 rotates, in the exposure optical head 69, the second mirror 70 rotates about the rotation axis of the hollow motor 66, and the second mirror 71 and the objective lens 72 are integrated with this. Thus, it moves on an arc centered on the second mirror 70. That is, the objective lens 72 of the exposure optical head 69 moves on the driving locus F that is inscribed in the outermost recording radius R and circumscribed in the innermost recording radius r as shown in FIG.

Next, the operation of the apparatus configured as described above will be described.
In manufacturing an optical disc, first, a photoresist, which is a photosensitive material, is applied to a glass original plate, which is used as an optical disc master 3. Next, this optical disc master 3 is exposed with a laser beam, information to be recorded is processed into a concave shape, and this is recorded as a pit signal. That is, exposure and recording on the optical disc master 3 are performed as follows. When the spindle motor 61 rotates at a constant rotational speed, the turntable 62 rotates at a constant rotational speed in response to the rotation, and the optical disc master 3 adsorbed and fixed to the turntable 62 also rotates at a constant rotational speed.

  On the other hand, when a laser beam is output from the laser oscillator 64, the laser beam is incident on the first mirror 65 and passes through the hollow portion 67 of the hollow motor 66 to the second mirror 70 of the exposure optical head 69. To reach. Then, the laser beam is reflected by the second mirror 70 in a direction parallel to the disk master, further reflected by the third mirror 71, and irradiated to the optical disk master 3 by the objective lens 72 as a focused light focusing spot. Is done.

  At this time, the hollow motor 66 is driven to rotate at a predetermined speed. By the rotational drive of the hollow motor 66, the second mirror 71 and the objective lens 72 integrally move on an arc around the second mirror 70 as a center. That is, the objective lens 72 of the exposure optical head 69 moves along the drive locus F that is inscribed in the outermost recording radius R and circumscribed in the innermost recording radius r as shown in FIG. The drive locus F is an arc having a diameter of (R + r), for example.

When exposure / recording on the optical disc master 3 is completed in this way, information is copied from the optical disc master 3, and a metal stamper necessary for replicating the optical disc is created using this information as a master. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, according to the seventh embodiment, an apparently high resolution (error is reduced to 1 / 3.14) can be obtained in the track direction, and information can be recorded on the optical disc master 3. High resolution can be achieved and high density recording is possible. In addition, since the center S of the arc serving as the locus of the laser beam is arranged inside the optical disc master 3, the distance between the second mirror 70 and the third mirror 71 is shortened to irradiate the laser beam. This is ideal for high-density information recording on the optical disc master 3. In addition, if the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

(8) Next, an eighth embodiment of the present invention will be described. The same parts as those in FIG. 16 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 17 is a block diagram of an optical disc master exposure apparatus to which the optical disc master exposure method is applied. On the surface plate 60, two base plates 80 and 81 are supported by support members 82 and 83 at predetermined intervals, respectively. Among these, a laser oscillator 84 is provided on the upper base plate 80, and a first mirror 85 is disposed on a laser beam optical path output from the laser oscillator 84. A motor 86 is provided on the lower base plate 81, and an exposure optical head 87 is connected to the rotation shaft of the motor 86. The exposure optical head 87 includes a second mirror 88, a third mirror 89, and an objective lens 90.

  Of these, the second mirror 88 has a mirror surface disposed at an angle of 45 ° with respect to the surface of the optical disc master 3, and reflects the laser beam reflected by the first mirror 85 in a direction parallel to the disc master. To do. The third mirror 89 is arranged with respect to the second mirror 88 at a distance of one half of the total distance of the outermost recording radius R and the innermost recording radius r in the optical disc master 3. The third mirror 89 has a mirror surface arranged at an angle of 45 ° with respect to the surface of the optical disc master 3, and reflects the laser beam reflected by the second mirror 88 toward the optical disc master 3. It is.

  The objective lens 90 is disposed on the optical path of the reflected laser beam of the third mirror 89 and includes a focus actuator. The objective lens 90 always irradiates the optical disc master 3 with the laser beam to the optical disc master 3 as a focused light focusing spot. Is. Here, when the motor 86 rotates, in the exposure optical head 87, the second mirror 88 rotates about the rotation axis of the motor 86, and the second mirror 88 and the objective lens 90 are integrated with this. It moves on an arc centered on the second mirror 88. That is, the objective lens 90 of the exposure optical head 87 moves on the drive locus F that is inscribed in the outermost recording radius R and circumscribed in the innermost recording radius r as shown in FIG.

Next, the operation of the apparatus configured as described above will be described.
In the manufacture of an optical disk, when the spindle motor 61 rotates at a constant rotation speed, the turntable 62 rotates in response to the rotation, and the optical disk master 3 adsorbed and fixed to the turntable 62 also rotates at a constant rotation speed. To do.
On the other hand, when a laser beam is output from the laser oscillator 84, the laser beam is incident on the first mirror 85 and reaches the second mirror 88 of the exposure optical head 87. Then, the laser beam is reflected by the second mirror 88 in the direction of 45 °, further falls on the third mirror 89, and is irradiated on the optical disc master 3 as a focused light focusing spot by the objective lens 90.

  At this time, since the motor 86 is rotationally driven at a predetermined speed, the third mirror 89 and the objective lens 90 integrally move on the arc around the second mirror 88. That is, the objective lens 90 of the exposure optical head 87 moves along the drive locus F that is inscribed in the outermost recording radius R and circumscribed in the innermost recording radius r as shown in FIG. This drive locus F is an arc having a diameter of (R + r).

  When exposure / recording on the optical disc master 3 is completed in this way, information is copied from the optical disc master 3, and a metal stamper necessary for replicating the optical disc is created using this information as a master. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, according to the eighth embodiment, as in the seventh embodiment, an apparently high resolution (error is reduced to 1 / 3.14) in the track direction can be obtained. Therefore, the optical disc master 3 can achieve high resolution at the time of information recording and perform high density recording. In addition, since the center S of the arc serving as the locus of the laser beam is arranged inside the optical disc master 3, the distance between the second mirror 88 and the third mirror 89 is shortened to irradiate the laser beam. This is ideal for high-density information recording on the optical disc master 3. In addition, if the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

Note that the seventh and eighth embodiments may be modified as follows.
For example, in the seventh and eighth embodiments, the exposure optical heads 69 and 87 are rotated so that the objective lenses 72 and 90 are inscribed in the outermost recording radius R as shown in FIG. While moving on a driving locus F circumscribing the inner recording radius r, the optical heads 69 and 87 for exposure are fixed, the spindle motor 61 side is rotated, and the locus of the laser beam on the optical disc master 3 is shown in FIG. The driving trajectory F shown in FIG. 6 may be obtained, and even if configured in this manner, the same effects as those of the seventh and eighth embodiments can be obtained.

(9) Next, a ninth embodiment of the present invention will be described.
FIG. 18 is a view showing the surroundings of the turntable such as the rotary table 23 on which the optical disc master 3 used in the optical disc master exposure apparatus is placed. Here, a case where the present invention is applied to the seventh and eighth embodiments will be described. A turntable 91 is connected to the rotation shaft of the spindle motor 61. The turntable 91 includes a groove of an adsorption mechanism 92 that adsorbs the optical disc master 3 in an area smaller than an area within the innermost recording radius r of the optical disc master 3.

  An image sensor 93 as an exposure light sensor is provided below the surface of the optical disc master 3 opposite to the surface irradiated with the laser beam. The image sensor 93 includes a plurality of light receiving elements, and is formed in an arc shape corresponding to the driving locus F of the objective lens of the exposure optical heads 69 and 87, for example, as shown in FIG. The image sensor 93 receives a laser beam that passes through the optical disc master 3 and outputs a light reception signal corresponding to the light reception position.

  The feedback control unit 94 receives the light reception signal output from the image sensor 93, detects the condensing spot position of the laser beam irradiated to the optical disc master 3 from the light reception signal, and detects the condensing spot position and the spot setting position. And the exposure optical heads 69 and 87 are positioned so that the difference is eliminated. The feedback control unit 94 counts the reference clock when the exposure optical heads 69 and 87 are moved according to the driving locus F, and a spot setting position corresponding to the count value is set in advance.

  With such a configuration, the following operation is provided in addition to the operations of the seventh and eighth embodiments. That is, the suction mechanism 92 that sucks the optical disc master 3 sucks the optical disc master 3 in a region narrower than the area within the innermost recording radius r of the optical disc master 3 and corresponds to the recording area of the optical disc master 3. Since a space is formed on the lower surface of the optical disc 3, even when the laser beam for exposure / recording on the optical disc master 3 is transmitted through the optical disc master 3, it is reflected and does not return to the optical disc master 3 again.

  Therefore, the exposure unevenness at the time of exposure / recording on the optical disc master 3 can be completely avoided.

Further, the laser beam transmitted through the optical disc master 3 enters the image sensor 93 with a spread angle as shown in FIG. The image sensor 93 receives a laser beam having a divergence angle transmitted through the optical disc master 3 with a plurality of light receiving elements, and outputs a light receiving signal corresponding to the light receiving position.

  The feedback control unit 94 receives the light reception signal output from the image sensor 93, compares the light reception signal with a preset reference level a, and determines an intermediate position (2b) of the light reception signal that is equal to or higher than the reference level a. / 2) is estimated as the focused spot position of the laser beam. The feedback control unit 94 obtains a difference between the focused spot position and the spot setting position, and positions the exposure optical heads 69 and 87 so that the difference is eliminated.

  As described above, in the ninth embodiment, in addition to the effects of the seventh and eighth embodiments, the uneven exposure of the optical disc master 3 can be avoided, and the exposure optical heads 69 and 87 are positioned. Thus, the laser beam condensing spot position can be controlled to a predetermined position, and the information recording can be densified. In addition, if the optical disc is replicated using such an optical disc master 3, information is recorded at a high density.

(10) Next, a tenth embodiment of the present invention will be described.
The tenth embodiment of the present invention is an optical disc master exposure method that is an improved optical disc master suction method. This optical disc master exposure method includes a first step of bringing the suction surface of the turntable into an atmospheric pressure state when the optical disc master 3 is placed on the turntable, and a suction surface of the turntable after the first step. A second step of setting a positive pressure between the optical disk master 3 and the optical disc master 3, and after the second step, a predetermined vacuum state between the suction surface of the turntable and the optical disc master 3 with a plurality of degrees of vacuum. And after the third step, information recording is performed by irradiating the optical disc master 3 with a laser beam.

  FIG. 21 is a configuration diagram of a suction mechanism of an optical disk master exposure apparatus to which such an optical disk master suction method is applied. A turntable 101 is connected to the rotation shaft of the spindle motor 100, and the optical disc master 3 is sucked and fixed on the turntable 101. In this turntable 101, the suction surface groove 102 is formed with a convex portion at a portion corresponding to the exposure area of the optical disc master 3 as shown in FIG. 22, or only a groove (concave portion) as shown in FIG. ing. The suction groove of the turntable 101 includes two stages of electromagnetic air valves in series via a pipe, that is, a first stage electromagnetic air valve (hereinafter referred to as a first electromagnetic air valve) 103, a second stage The electromagnetic air valve (hereinafter referred to as a second electromagnetic air valve) 104 is connected through a pipe.

  These first and second electromagnetic air valves 103 and 104 each have three valve ports R, A, and P, and are connected in series through the valve ports A and R. And the vacuum pump 105 is connected to the valve opening R of the 2nd electromagnetic air valve 104 of a back | latter stage through piping. A compressed air source 107 is connected to the valve opening P of the first electromagnetic air valve 103 through a pipe via a first regulator 106, and the electromagnetic valve is connected to the valve opening P of the second electromagnetic air valve 104. The compressed air source 107 is connected through a pipe via an attached ejector 108 and a second regulator 109.

  However, the first electromagnetic air valve 103 selects the valve port P on the compressed air source 107 side or the valve port R on the second electromagnetic air valve 104 side with respect to the valve port A on the suction surface side of the turntable 101. To switch. The second electromagnetic air valve 104 has a valve port P on the compressed air source 107 side or a valve port R on the vacuum pump 105 side with respect to the valve port A on the suction surface side on the first electromagnetic air valve 103 side. Select and switch.

  The pressure control device 110 controls the operation of the first and second electromagnetic air valves 103 and 104 and the ejector with electromagnetic valve 108 so that the suction surface of the turntable 101 is in an atmospheric pressure state, and then the suction surface of the turntable 101 A positive pressure is applied between the optical disk master 3 and the vacuum surface between the suction surface of the turntable 101 and the optical disk master 3 at a plurality of stages, for example, (atmospheric pressure-100 mmHg) to (atmospheric pressure-200 mmHg). It has a function of reaching a low degree of vacuum and then a high degree of vacuum (atmospheric pressure−700 mmHg) or less.

Next, the case where the operation of the apparatus configured as described above is applied to the turntable in the optical disk master exposure apparatus of the seventh embodiment will be described.
In manufacturing an optical disc, first, a photoresist, which is a photosensitive material, is applied to a glass original plate, which is used as an optical disc master 3. This optical disc master 3 is attracted and fixed to the turntable 101 (turntable 62 in the seventh embodiment). That is, as a first step, the pressure control device 110 opens the first electromagnetic air valve 103 to the second electromagnetic air valve 104 side (valve port A → R). The electromagnetic valve ejector 108 closes the second regulator 109 to cut off the supply of compressed air from the compressed air source 107. At this time, the electromagnetic valve-equipped ejector 108 is opened to the atmospheric pressure side. Thereby, the adsorption surface of the turntable 101 is formed in an atmospheric pressure state. The optical disc master 3 is placed on the suction surface of the turntable 101 in the atmospheric pressure state.

In the second step, when the optical disc master 3 is centered with respect to the turntable 101, that is, when the center position of the optical disc master 3 is positioned with respect to the rotation center of the turntable 101, the pressure control device 110 performs the first electromagnetic operation. The air valve 103 is opened to the compressed air source 107 side (valve port P). The electromagnetic valve-equipped ejector 108 may be in any state. Compressed air from the compressed air source 107 is supplied to the adsorption surface of the turntable 101 through the first regulator 106 and the first electromagnetic air valve 103 by opening the first electromagnetic air valve 103 on the valve port P side. Is done. At this time, the compressed air supplied to the adsorption surface of the turntable 101 is supplied regardless of the state of other devices. Further, the supply pressure of the compressed air supplied to the turntable 101 is regulated by the first regulator 106 and set to a slight positive pressure, for example, about +1 kgf / cm ^{2 at the} maximum with respect to the atmospheric pressure. Thereby, a positive pressure (positive pressure) is set between the optical disc master 3 and the turntable 101.

  However, the optical disc master 3 is centered by the centering mechanism with respect to the turntable 101 in a state of positive pressure between the optical disc master 3 and the turntable 101.

  Thereafter, in the third step, the pressure control device 110 opens the first electromagnetic air valve 103 to the second electromagnetic air valve 104 side (valve port A → R), and the second electromagnetic air valve 104. Is opened to the ejector with solenoid valve 108 side (valve port A → P). Then, the electromagnetic valve-equipped ejector 108 is supplied with compressed air from the compressed air source 107 through the second regulator 109 to form a vacuum state. At this time, the supply pressure to the ejector with solenoid valve 108 is regulated by the second regulator 109, and the ultimate degree of vacuum of the ejector with solenoid valve 108 is low so that there is no positional deviation at the time of adsorption after the centering. For example, (atmospheric pressure−100 mmHg) to (atmospheric pressure−200 mmHg) is set. As a result, the optical disc master 3 is adsorbed to the turntable 101 by the low degree of vacuum, that is, lightly adsorbed.

  Next, the pressure control device 110 opens the first electromagnetic air valve 103 to the second electromagnetic air valve 104 side (valve port A → R), and opens the second electromagnetic air valve 104 to the vacuum pump 105 side (valve. Open to mouth A → R). At this time, the electromagnetic valve-equipped ejector 108 may be in any state. As a result, the suction surface of the turntable 101 is sucked by the vacuum pump 105 through the first and second electromagnetic air valves 103 and 104 to suck and fix the optical disc master 3. At this time, the ultimate degree of vacuum on the suction surface of the turntable 101 is set to a high degree of vacuum, for example, (atmospheric pressure−700 mmHg) or less.

  When the optical disc master 3 is attracted and fixed to the turntable 101 in this way, in the optical disc master exposure apparatus of the seventh embodiment, the spindle motor 61 rotates at a constant rotational speed and responds thereto. Thus, the turntable 62 rotates at a constant rotational speed, and the optical disc master 3 that is sucked and fixed to the turntable 62 also rotates at a constant rotational speed.

  On the other hand, when a laser beam is output from the laser oscillator 64, the laser beam is incident on the first mirror 65, passes through the hollow portion 67 of the rotating hollow motor 66, and the second mirror of the exposure optical head 69. Reach 70. Then, the laser beam is reflected by the second mirror 70, further reflected by the third mirror 71, and irradiated on the optical disc master 3 by the objective lens 72 as a just-focused focused spot.

  At this time, since the hollow motor 66 is rotationally driven at a predetermined speed, the objective lens 72 of the exposure optical head 69 moves along an arc of the drive locus F shown in FIG.

As a result, the optical disc master 3 is exposed to a laser beam, information to be recorded is processed into a concave shape, and this is recorded as a pit signal.

  By the way, the laser beam applied to the optical disc master 3 passes through the optical disc master 3 and reaches the turntable 101. The suction surface of the turntable 101 corresponds to the exposure area of the optical disc master 3 as shown in FIG. Since only the protrusions or grooves (recesses) are formed as shown in FIG. 23, the unevenness in exposure due to the influence of the reflected laser beam from the turntable 101 is reduced.

  When exposure / recording on the optical disc master 3 is completed in this way, information is copied from the optical disc master 3, and a metal stamper necessary for replicating the optical disc is created using this information as a master. Then, duplication is performed using the metal stamper, and the optical disc as the final product is completed.

  As described above, in the tenth embodiment, when the optical disk master 3 is placed on the turntable 101, the suction surface of the turntable 101 is brought to atmospheric pressure, and then the suction surface of the turntable 101 and the optical disk master are placed. 3 is set to a positive pressure state, and next, the optical disk master 3 is sucked and fixed at a two-stage vacuum degree of low vacuum and high vacuum between the suction surface of the turntable 101 and the optical disk master 3. In other words, since the suction surface of the turntable 101 is gradually or continuously shifted from atmospheric pressure to high vacuum so that no imbalance occurs in the vacuum state, the optical disc master 3 is centered on the turntable 101 in advance. Then, even if it is sucked and fixed, the optical disk master can be sucked without the centering being shifted.

  Further, since the suction surface of the turntable 101 corresponding to the exposure area of the optical disc master 3 is formed only on the convex portion or the groove (concave portion), the exposure unevenness due to the influence of the reflected laser beam from the turntable 101 is reduced. it can.

Note that the tenth embodiment may be modified as follows. For example, not only the vacuum pump 105 and the electromagnetic valve ejector 108 which are two vacuum generators are used, but the ultimate vacuum degree is achieved by an electro-air regulator that can use one vacuum generator and electrically convert the supply pressure. May be controlled to continuously increase the ultimate vacuum and perform adsorption.
In addition, the two-stage electromagnetic air valves are not limited to be connected in series, and a plurality of electromagnetic air valves may be connected to adjust the ultimate vacuum in a plurality of stages.

  Further, the tenth embodiment has been described as applied to the turntable in the optical disc master exposure apparatus of the seventh embodiment, but the turntable in the optical disc master exposure apparatus of the eighth embodiment has been described. It can also be applied to.

  As described above, by using the optical disk master exposure method and apparatus of the present invention, it is possible to perform exposure with a resolution that greatly exceeds the limits of the laser interferometer and encoder to be used, regardless of the drive system. It will be possible to contribute to the future increase in capacity of optical disks.

  In addition, since the optical disk of the present invention can perform high-density recording with high accuracy, it is possible to provide a high-quality signal with less errors and jitter when the information in the optical disk is increased in density.

INDUSTRIAL APPLICABILITY As described above, the optical disc master exposure method and exposure apparatus according to the present invention are not only for CD / DVD, but also for creating a master disc for an optical disc with a higher recording density in the future. This is a useful technique and is particularly suitable when it is desired to configure the apparatus at a low cost. Further, the optical disc according to the present invention can provide a compact recording medium at a low cost with respect to an increase in the amount of information accompanying future development of multimedia culture.

The figure which shows 1st Embodiment of the optical disk original recording exposure method concerning this invention. The figure which shows the locus | trajectory of the exposure light on the track | truck by the same exposure method. The figure which shows the locus | trajectory of the exposure light on the track | truck by the same exposure method. The figure which shows the angle which cross | intersects the track pitch with respect to a scanning angle. The figure which shows a scanning angle. The figure which shows the comparison with the sensitivity of the prior art with respect to a scanning angle. The figure which shows the modification of the locus | trajectory of exposure light. The figure which shows the modification of the locus | trajectory of exposure light. The block diagram which shows 2nd Embodiment of the optical disk original recording exposure apparatus concerning this invention. The block diagram which shows 3rd Embodiment of the optical disk original recording exposure apparatus concerning this invention. The block diagram which shows 4th Embodiment of the optical disk original recording exposure apparatus concerning this invention. The figure which shows narrowing of the laser beam spot by a toroidal mirror. The block diagram which shows 5th Embodiment of the optical disk original recording exposure apparatus concerning this invention. The specific block diagram of a mirror with a correction | amendment. The specific block diagram which provided the piezoelectric element group of the mirror with a correction | amendment. The block diagram seen from the upper side which shows 6th Embodiment of the optical disk original recording exposure apparatus concerning this invention. The block diagram seen from the side of the optical disk original disc exposure apparatus. The block diagram which shows 7th Embodiment of the optical disk original recording exposure apparatus concerning this invention. The block diagram which shows 8th Embodiment of the optical disk original recording exposure apparatus concerning this invention. The block diagram which shows 9th Embodiment of the turntable of the optical disk original recording exposure apparatus concerning this invention. FIG. 3 is an external view showing an arrangement state of image sensors. The figure which shows the light reception effect | action of an image sensor. The block diagram which shows 10th Embodiment of the adsorption | suction mechanism of the optical disk original recording exposure apparatus concerning this invention. The figure which shows the suction surface groove | channel shape of a turntable. The figure which shows the suction surface groove | channel shape of a turntable. The block diagram of the conventional optical disk master exposure apparatus. The figure which shows the drive locus | trajectory of the conventional optical head for exposure.

Explanation of symbols

  3: optical disc master, 10: surface plate, 11: first motor, 12: turntable, 11a: rotating shaft, 13: fixed member, 14: second motor, 15: turntable, 19a: balancer, 19b: Lens mount, 19c: imaging lens, 16: support arm, 17: laser oscillator, 18: mirror, 20: surface plate, 21: support, 22: base plate, 23: rotary table, 24: laser oscillator, 24a: Optical system, 25: first mirror, 26: mirror lifting mechanism, 27: second mirror, 28: guide body, 29: rotary motor, 30: conical mirror, 30a: rotation control unit, 31: first Toroidal mirror, 32: second toroidal mirror, 33: first corrected mirror, 34: second corrected mirror, 35: notched hinge, 33a, 34a: mirror surface, 36, 37: Electrical element group, 38: curved surface control unit, 40: master disk suction disk, 41: XY drive mechanism, 42, 43: X axis guide, 44, 45: X axis slider, 46, 47: Y axis guide, 48: XY stage 49: exposure optical head, 50: laser oscillator, 51: 45 ° mirror, 52: 45 ° mirror, 60: surface plate, 61: spindle motor, 62: turntable, 63: base plate, 64: laser oscillator, 65: first mirror, 66: hollow motor, 67: hollow portion, 68: rotating body, 69: optical head for exposure, 70: second mirror, 71: third mirror, 72: objective lens, 80, 81: Base plate, 82, 83: Support member, 84: Laser oscillator, 85: First mirror, 86: Motor, 87: Optical head for exposure, 88: Second mirror, 89: Third mirror, 90 : Objective lens 91: Turntable, 92: Suction mechanism, 93: Image sensor, 94: Feedback control unit, 100: Spindle motor, 101: Turntable, 102: Suction surface groove, 103: First electromagnetic air valve, 104: Second 105: vacuum pump, 106: first regulator, 107: compressed air source, 108: ejector with solenoid valve, 109: second regulator, 110: pressure control device.

Claims (5)

A light source that outputs exposure light that irradiates the optical disc master to form a spiral or concentric pit array;
Rotating mechanism that relatively rotates and moves the optical disc master and the exposure light, respectively, and makes the trajectory of the exposure light irradiated to the optical disc master an arc,
An optical disc master exposure apparatus comprising:   2. The optical disk master exposure apparatus according to claim 1, wherein the rotating mechanism swings the optical disk master so that a path of irradiation of the exposure light on the optical disk master is an arc.   2. The optical disc master exposure apparatus according to claim 1, wherein the rotating mechanism moves the exposure light in an arc shape and irradiates the optical disc master. An exposure optical head for emitting the exposure light;
The rotation mechanism includes an XY stage that moves the exposure optical head in an arc shape.
2. An optical disc master exposure apparatus according to claim 1, wherein:   The rotation mechanism includes: a first rotation mechanism that rotates the optical disc master; and a second rotation mechanism that is provided offset from a rotation axis of the first rotation mechanism and rotates the exposure light or the optical disc master. 2. An optical disc master exposure apparatus according to claim 1, further comprising:

Images