JP2000061666A - Laser texture device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form uniform bumps on both front and rear sides of a disk through a simple optical structure, even if a means or the like that branches a laser beam from a laser beam source changes in the characteristics by heat and other external effects. SOLUTION: In the common optical path 14 of a laser beam irradiating means 13, which is for forming simultaneously bumps on both front and rear faces of a disk 10 a laser beam source 20 and an isolator 21 are arranged, as are an ND filter 22, a beam expander 23 and a first polarizing beam splitter 24, with the isolator rotating the polarizing face of the laser beam of linearly polarized light at an angle of 45 deg.. With the first polarizing beam splitter 24 splitting the beam into P and S polarizing components, the power of each laser beam passing through the P and S polarizing optical paths 15P, 15S is individually adjusted by λ/2 wavelength plates 26P, 26S and second polarizing beam splitters 27P, 27S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser texture apparatus for irradiating a limited range of CSS areas on both front and back surfaces of a magnetic disk with a laser pulse to perform texture processing, and particularly to a single laser light source. The present invention relates to a laser texture device capable of performing uniform texturing on both front and back surfaces of a disc.

[0002]

2. Description of the Related Art A magnetic disk drive device has a spindle for rotating a magnetic disk (hereinafter, simply referred to as a disk). While the disk is rotated by the spindle, a magnetic head is made to face a disk surface with a predetermined gap. In this state, information is written or read. The operation of the magnetic head at this time is as follows. First, when the disk is stationary, the magnetic head is brought into contact with a predetermined position on the surface of the disk, and when the disk starts to rotate, the magnetic head slides on the surface of the disk to increase the rotation speed. During a steady rotation speed, the air flow generated between the magnetic head and the disk causes the magnetic head to float stably with a predetermined gap from the disk surface. The magnetic head thus levitated is displaced to the data recording area,
Information is written and read. Also, when the rotation of the disk is stopped, the magnetic head is moved to a predetermined position again, and when the levitation force due to the decrease in the rotation speed of the disk is reduced, the magnetic head slides on the disk surface, and when the disk is stopped, the magnetic head moves at that position. It becomes stationary.

The above operation method of the magnetic head is called a contact start / stop (CSS) method. Therefore, the magnetic head is stationary on the surface of the disk in addition to the data recording area where information is written and read. A CSS area that is held in a state is formed. Here, the CSS area is an area provided with minute projections for smoothly flying the magnetic head with low friction, and is usually formed in an annular shape having a predetermined width in the vicinity of the inner peripheral edge of the disk. It Then, the texturing is the surface processing of the disk in which the minute protrusions are formed in the CSS area thus limited.

In performing texturing on the CSS area, it is necessary to form minute and uniform projections with extremely high precision. If the processing accuracy is poor, the magnetic head does not fly smoothly during the levitation operation, sticks to the disk surface, and the friction between the magnetic head and the disk surface increases when shifting to a stationary state, so-called CSS. The smoothness of operation will be impaired. In particular, in recent years, in order to improve the magnetic recording density, the magnetic head is levitated from the disk by an extremely small amount, so that the accuracy of the texturing is further improved, and the projections are miniaturized and uniformized. There is a need.

The texturing is performed not only for the CSS area described above but also for improving the magnetic orientation over the entire surface of the disk. In this case, tape polishing is generally performed. Therefore, CS
For the processing of the S area, this tape polishing method can be adopted. As a disk surface processing method, there is a method by chemical etching. However, the texture processing using laser light, that is, the laser texture method is most advantageous in order to perform highly accurate partial processing in a limited area such as the CSS area on the surface of the disk.

The laser texture device comprises a laser light irradiating means including a laser light source and an objective lens. The disk is mounted on a spindle means, and while the disk is rotationally driven by the spindle means, the laser light irradiating means has a laser light source. A laser pulse is emitted from the laser, the laser light is focused by the objective lens so that the spot diameter becomes a predetermined spot diameter, and the disk surface is irradiated with the laser light. Therefore, the surface of the disk is locally heated by the energy of the laser light applied to the surface of the disk, and the vicinity of the surface of the disk is softened or melted and minute projections (hereinafter, these projections are called bumps). Is formed.

The CSS area has a limited width on the disk surface and is formed on the inner peripheral side of the disk.
In the processing, the disk is rotationally driven to irradiate the laser pulse with a predetermined pitch interval in the rotational direction, and the irradiation position of the laser light is moved in the radial direction of the disk.
As a result, spiral bumps are formed on the surface of the disk, and a texture zone having a predetermined width is formed on the surface of the disk. Therefore, at least the objective lens is made movable while the disc is rotated by the spindle means.
When facing the inner edge of the area (outgoing start position),
By controlling the number of revolutions of the disk and the pulse interval of the laser pulse to be irradiated from the start of the laser pulse emission to the end on the outer peripheral side (exit end position), the inner peripheral side of the disc is controlled. Bumps are formed at a predetermined pitch interval in a predetermined region limited to.

The CSS area is an area where the magnetic head abuts in a stationary state, and the bumps that are in direct contact with the magnetic head must have a constant protrusion height and be formed at a uniform pitch. In order to form an appropriate bump, the power of the laser pulse from the laser light source forming the laser light irradiation means must be constant, and the disk must be placed at a position where the objective lens is in focus. If the laser power is lower than the set value, bumps having a sufficient height cannot be formed, and if the laser power is extremely reduced, the bumps themselves cannot be formed. On the other hand, if the disc is in a so-called defocus state in which the disc is displaced from the focal point of the objective lens, accurate bumps cannot be formed even when a laser beam having a predetermined power is emitted from the laser light source.

Since data is written and read on both the front and back surfaces of the magnetic disk, the above-described texture processing must be performed on both the front and back surfaces of the disk. And, of course, the shape of the formed bump is
It is necessary to make the front and back surfaces substantially uniform. In order to texture both the front and back sides, there is a method in which one side of the disc is first processed, then the disc is inverted and the opposite side is processed. In this method, since processing can be performed on both front and back surfaces of the disk under substantially the same conditions, it is possible to secure processing uniformity on both front and back surfaces. However, there is a problem that a disk reversing mechanism is required and the processing time becomes long.

As another method for simultaneously processing the surface, two sets of laser light irradiating mechanisms from a laser light source to an objective lens are used, which are arranged opposite to each other on the front and back surfaces of the disk, and the disk is rotationally driven. However, there is also a method of processing both the front and back sides at the same time. However, there is a problem that not only the apparatus configuration becomes large, but also the powers of the laser beams from the two laser beam irradiation mechanisms need to be accurately matched, and the adjustment thereof is extremely troublesome.

Further, if a beam splitter is used, at least the laser light source can be shared for processing both front and back surfaces. As a method of dividing the optical path of the laser light from the laser light source into two by using the beam splitter, for example, the method disclosed in Japanese Patent Laid-Open No. 10-91947 is conventionally known. Therefore, the optical configuration of this known texture device is shown in FIG.

In the figure, reference numeral 1 is a laser light source, and an isolator 2 is provided in the optical path of the laser beam from the laser light source 1. The laser beam transmitted through this isolator 2 enters a beam splitter 3 and The beam splitter 3 splits the light into two optical paths of transmission and reflection. The two optical paths branched in this way are provided with parallel beam forming means 4a and 4b formed of beam expanders, and the laser beams converted into parallel beam by these parallel beam forming means 4a and 4b are ND filters 5a and 5b. The light quantity is adjusted by. Furthermore, N
Electromagnetic shutters 6a and 6b for controlling the start and end of texture are provided in front of the D filters 5a and 5b, and objective lenses 7a and 7b are provided in front of the electromagnetic shutters 6a and 6b.
Is provided.

With the above structure, the disk 8 is arranged between the objective lenses 7a and 7b so that the laser light source 1 emits a laser pulse from a predetermined position, and the electromagnetic shutters 6a and 6b are opened. Then, the formation of bumps from predetermined positions on both front and back surfaces of the disk 8 is started. By moving the objective lenses 7a and 7b in the radial direction as the disk 8 rotates, bumps having a predetermined width are formed on the disk 8. Further, when the processing end position is reached, the electromagnetic shutters 6a and 6b are closed. As a result, texture processing is performed on both the front and back surfaces of the disk 8.

[0014]

By the way, it is necessary to form bumps having substantially the same shape on both front and back surfaces of a disk. For this purpose, the laser beams emitted from the objective lenses must have the same power. I won't. Since the beam splitter for splitting the laser beam splits the transmitted light and the reflected light, the amount of light is set to be exactly equal to each other, and the powers in the two optical paths are equal to each other. It is unavoidable that the assembly error of (2) occurs, and thus the balance in the two optical paths may be slightly disturbed. Further, the characteristics of the beam splitter change due to the influence of heat, and as a result, the distribution ratio of the amount of light in the beam splitter may change. Thus, the beam splitter alone cannot always irradiate the front and back surfaces of the disk with the laser beam of the same power. Further, since the parallel light flux forming means and the ND filter are arranged in each branched optical path, the optical structure thereof becomes complicated, and the structure of the laser texture device as a whole becomes large. is there.

The present invention has been made in view of the above points, and an object thereof is a simple optical configuration.
It is to be able to form even bumps on both the front and back surfaces of the disc.

[0016]

In order to achieve the above-mentioned object, the present invention mounts a disk on a spindle,
By irradiating both sides of the disk with laser pulses from a laser light irradiating means including a laser light source and an objective lens at a predetermined pitch while rotating the disk by this spindle, the front and back surfaces of the disk are regularly regulated over a predetermined range. And a polarization plane control means for rotating the polarization plane of the laser light composed of linearly polarized light from the laser light source by 45 °, and a polarization plane control means. A polarization beam splitter that splits the output light from the P-polarization component into two light beams of S-polarization component is provided in a common optical path portion for processing both front and back surfaces of the disk, and two optical paths branched by the polarization beam splitter are provided. The power of the incident light to the objective lens provided in each of the P polarization component optical path and the S polarization component optical path is It is an its features that it has a configuration in which a laser power adjusting means for adjusting such that properly.

Here, an isolator for cutting the reflected light from the workpiece is generally provided on the output side of the laser light source. The laser light from the laser light source is linearly polarized light, and some isolators have a function of rotating the plane of polarization of this linearly polarized light by 45 °. Therefore, if an isolator having such a function is used, this isolator can be shared with the polarization plane control means. Further, in order to control the spot diameter of the laser spot on the disc, a beam expander for expanding the laser beam from the laser light source is provided,
This beam expander can be provided between the isolator and the polarization beam splitter, and this is desirable in that the beam expander can be commonly used for processing both front and back surfaces of the disc. Further, as the laser power adjusting means, a λ / 2 wavelength plate and a second polarization beam splitter are provided in the P polarization component optical path and the S polarization component optical path, respectively, and between the second polarization beam splitter and the objective lens. A power detector is arranged in the power detector, and the polarization azimuth vector by the λ / 2 wave plate can be changed so that the light of the P-polarized component and the light of the S-polarized component detected by each of the power detectors have a predetermined power. it can.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, reference numeral 10 denotes a disk, on which a data recording area 10D and a CSS on which a magnetic head (not shown) is stationary.
A region 10C is formed. The CSS area 10C is formed in an annular shape at a portion close to the inner circumference of the disk 10, as shown by the hatching in FIG. It is this CSS region 10C that is subjected to surface processing by laser texture. In addition, by this texturing, minute protrusions having the shape shown in FIG. 2 are formed on the surface of the disk 10 in the CSS region 10C. One unit of the minute protrusion is called a bump 11. However, the bumps formed on the surface of the disk 10 are not limited to the shapes shown in this figure, but may take various shapes depending on the material of the disk, the power of the laser beam, the focused spot diameter, and the like.

FIG. 3 shows the overall structure of an apparatus for performing laser texturing. As is apparent from this figure, the processing apparatus is a spindle means 1 for rotating the disk 10.
2 and a laser beam irradiation means 13 for irradiating the surface of the disk 10 with a laser beam. The laser light irradiation means 13 can simultaneously perform texture processing on both surfaces of the disk 10. Spindle means 1
Reference numeral 2 detachably clamps the inner diameter of the disk 10 and is rotationally driven at a predetermined speed.

The laser light irradiating means 13 comprises a common optical path section 14, a P-polarized optical path section 15P and an S-polarized optical path section 15S. A laser light source 20, an isolator 21, an ND filter 22, a beam expander 23, and a first polarization beam splitter 24 are arranged in the common optical path unit 14. As the laser light source 20, for example, 1064
A YAG laser or the like having an oscillation frequency of nm that oscillates in a pulse is preferably used. When a continuous wave laser light source is used, a pulse generator is provided in the common optical path section 14.

The isolator 21 is composed of, for example, a Faraday rotation type, and its original function is to prevent return light from the disk 10 from entering the laser light source 20, and this isolator. Due to the action of the Faraday rotator in 21, the polarization plane of the linearly polarized laser beam emitted from the laser light source 20 is rotated by 45 ° Faraday, and this isolator 21 functions as a polarization plane control means. The ND filter 22 arranged on the output side of the isolator 21 constitutes a fixed light quantity adjusting means, and is for roughly reducing the light quantity of the light source from the laser light source 20 to a predetermined level in advance.

The laser beam whose light amount has been adjusted by the ND filter 22 is changed in its optical path by 90 ° by the reflection mirror 25a, and then the beam diameter of the laser beam is expanded by the beam expander 23 to be a parallel light flux. The reason for expanding the beam diameter in this way is to reduce the diameter of the laser spot on the disk 10 by the objective lens units 28P and 28S described later so as to be smaller. In this way, the laser beam whose diameter has been expanded and which has been converted into a parallel light beam is divided into light reflected by the first polarization beam splitter 24 and light transmitted therethrough. One of the transmitted light and the reflected light is a P-polarized component light, and the other is an S-polarized component light. Here, the polarization plane of the laser beam incident on the first polarization beam splitter 24 is changed by the isolator 21 to 4
Since it is rotated 5 °, the polarization beam splitter 24
The light of the P-polarized component and the light of the S-polarized component that are branched by the light source have substantially the same light amount.

The P-polarized component light from the polarization beam splitter 24 passes through the P-polarized optical path portion 15P, and the S-polarized component light passes through the S-polarized optical path portion 15S to reach both the front and back surfaces of the disk 10. The P-polarized light path portion 15P and the S-polarized light path portion 15S are provided with a laser power adjusting means including λ / 2 wave plates 26P and 26S and second polarization beam splitters 27P and 27S, respectively, and objective lens units 28P and 28S. It is provided. Since the P-polarized light path portion 15P and the S-polarized light path portion 15S are parallel to each other, the light path portion on the side that transmits the first polarization beam splitter 24, that is, P
A reflection mirror 25b is provided in the polarized light path portion 15P.

The second polarization beam splitter 27
Beam samplers 29P and 29S are interposed between the P and 27S and the objective lens units 28P and 28S,
The beam samplers 29P and 29S are sampled so as to reflect an amount of light of about several percent to several tens of percent, and the light reflected by the beam samplers 29P and 29S is power detectors 30P and 30S composed of photoelectric conversion elements.
It is designed to be taken into and measured by its power.

The λ / 2 wave plates 26P and 26S can be rotated by the rotation driving means 31P and 31S.
By rotating the half wave plates 26P and 26S,
It is possible to change the polarization azimuth vector of the laser beam passing through the P-polarized light path portion 15P and the S-polarized light path portion 15S, respectively. λ / 2 wave plate 26P, 26S
Among the polarization components of the light that passes through, only the light of the P polarization component in the second polarization beam splitter 27P of the P polarization optical path unit 15P, and the S polarization component in the second polarization beam splitter 27S of the S polarization optical path unit 15S. Only the light of is transmitted. Therefore, the amount of transmitted light, that is, the output power of the second polarization boom splitters 27P and 27S is λ / 2 wavelength plates 26P and 2P.
It changes according to the rotation angle of 6S.

As described above, the power detectors 30P,
The detection signal of 30S is taken into the rotation driving means 31P, 31S, and these rotation driving means 31 are taken in accordance with the fluctuation of the power.
By controlling the rotation angles of the λ / 2 wave plates 26P and 26S by P and 31S, specifically, the λ / 2 wave plates 26P and 26S are rotationally displaced based on the voltage signals from the power detectors 30P and 30S. As a result, the powers of the laser beams from the objective lens units 28P and 28S toward the front and back surfaces of the disk 10 are adjusted to be equal.

Therefore, the laser power adjusting means will be described in more detail with reference to FIG. When light having a polarization plane of 45 ° is incident on the first polarization beam splitter 24, P which passes through the first polarization beam splitter 24 is transmitted.
Polarized light path portion 15P and S-polarized light path portion 1 reflected from it
It branches to 5S. Of these, the light of the P-polarized component in the P-polarized light path portion 15P is incident on the λ / 2 wavelength plate 26P. Then, when the laser power detected by the power detector 30P is different from the preset value, a feedback signal based on the deviation from the power detector 30P is taken into the rotation driving means 31P, and only an amount corresponding to this signal voltage is obtained. The λ / 2 wave plate 26P is rotated in the arrow direction (or the opposite direction). As a result, λ /
In the two-wave plate 26P, the P-polarized component changes by the amount of change of the polarization azimuth vector, and the second polarization beam splitter 27
This second polarization beam splitter 2 when it is incident on P
In 7P, only the light of the P-polarized component is transmitted, and the light of the S-polarized component is reflected by the second polarization beam splitter 27P and diffused out of the system. That is, the λ / 2 wave plate 26P
Thus, the power of the P-polarized component is changed by the amount by which the plane of polarization is tilted, and the power of the laser beam to the objective lens unit 28P can be adjusted. The λ / 2 wavelength plate 26S and the second polarization beam splitter 27S in the S-polarized light path portion 15S also have similar functions.

The optical paths to the objective lens units 28P and 28S are parallel to each other, and in order to irradiate the front and back surfaces of the disk 10 with the laser beam, the optical paths need to be changed by 90 °. Moreover, the CSS area 10C of the disk 10 is located on the inner peripheral side thereof, and the spindle means 1
2 clamps the inner circumference of the disk 10. Therefore,
It is necessary to prevent the optical path to the disk 10, especially the optical path to the back side of the disk 10 from interfering with the spindle means 12. Therefore, the objective lens unit 28P,
The optical path of the laser beam emitted from 28S is bent 90 ° by the reflection mirrors 32P and 32S.

By using the texture processing apparatus configured as described above, while the disk 10 is mounted on the spindle means 12 and the disk 10 is rotated, the laser light irradiation means 13 irradiates the laser pulse. By moving the irradiation spot in the radial direction of the disk 10, the CSS regions 10C on both front and back surfaces of the disk 10 are textured. Then, during this time, the laser light irradiation means 13 is moved in the radial direction of the disk 10 by a driving means (not shown), so that the bumps 11 are formed in a spiral shape over a predetermined width on both the front surface and the back surface of the disk 10.

The bumps 11 formed on the CSS regions 10C on both the front and back sides of the disk 10 are, for example, minute protrusions having the shape shown in FIG. 2, 11H is the bump height, and 11D is the pitch interval. If it is accurately performed, the bumps 11 having a uniform height 11H are simultaneously formed on the both surfaces of the CSS region 10C at a constant pitch interval 11D. Here, the pitch interval 11
D is determined by the rotation speed of the disk 10 and the pulse interval. Therefore, it is necessary to keep the rotation speed of the disk 10 by the spindle 12 constant.

Further, the height of the bump 11 depends on the spot diameter of the irradiated laser beam on the disk 10 and the laser power. The control of the spot diameter is primarily determined by the objective lens units 28P and 28S. That is, both the front and back surfaces of the disk 10 must always be located at the focal position of the objective lens in the objective lens units 28P and 28S. Objective lens unit 2
By configuring 8P and 28S with an autofocus mechanism, even if the relative distance between the front and back surfaces of the disk 10 and the objective lens units 28P and 28S changes, focus adjustment can be performed by this autofocus mechanism. You can

In addition, the objective lens units 28P and 28S
The beam diameter of the incident light on the disk 10 also affects the irradiation spot diameter on the disk 10. The beam diameter of the laser beam is controlled by the beam expander 23. Since the beam expander 23 is provided in the common optical path portion 14, the P-polarized optical path portion 15P for processing one side surface of the disk 10 is also used. Also, the same beam diameter is obtained in the S-polarized light path portion 15S for processing the other side surface.

The laser beams applied to both the front and back surfaces of the disk 10 are split by the first polarization beam splitter 24, so that the light of the P-polarized component toward the P-polarized light path portion 15P and the S toward the S-polarized light path portion 15S. The polarization component light is set to be equal. However, the characteristics of the optical components forming the laser light irradiation means 13 change slightly due to the influence of heat. When the characteristics of the first polarization beam splitter 24 change due to the influence of heat or the like, there is a difference in power between the laser beam directed to the P-polarized optical path portion 15P and the laser beam directed to the S-polarized optical path portion 15S. In addition, the λ / 2 wave plate 26
P, 26S and second polarization beam splitters 27P, 2
Similarly, the characteristics of 7S change due to the influence of heat.

However, the laser power on the output side of the second polarization beam splitters 27P and 27S is detected by the power detectors 30P and 30S, and the λ / 2 wave plate 26 is detected.
Feedback control is performed on P and 26S. As described above, among the optical components that constitute the laser light irradiation means 13,
The polarization beam splitters 24, 27P, 27S and the λ / 2 wavelength plate 26P, which may change in characteristics due to heat or the like,
Laser power is measured at a position closer to the object than the position where 26S is disposed, and objective lens units 28P and 28S that are relatively stable to heat are located closer to the object than the laser power measurement position.
Since only (and a reflection mirror for guiding the optical path) is provided, the power of the laser beam applied to the disk 10 is always constant, and the laser beam of the same power can be applied to both front and back surfaces. .

Further, among the optical components constituting the laser light irradiation means 13, the laser light source 20 and the isolator 2 are provided.
Since the 1, ND filter 22, the beam expander 23, and the first polarization beam splitter 24 are arranged in the common optical path unit 14, the optical configuration of the laser light irradiation means 13 as a whole is simplified. Moreover, the λ / 2 wave plates 26P and 26S and the second polarization beam splitters 27P and 27S, which constitute the laser power adjusting means, and the beam samplers 29P and 29S and the power detectors 30P and 30S, which measure the laser power, are P polarization, respectively. Since it is provided in the optical path portion 15P and the S-polarized optical path portion 15S, the laser power can be adjusted individually and the power of the laser beam applied to both front and back surfaces of the disk 10 can be adjusted extremely accurately.

[0036]

As described above, according to the present invention, one laser light source, polarization plane control means for rotating the polarization plane of the linearly polarized laser light from this laser light source by 45 °, and this polarization plane. The output light from the control means is P-polarized component and S
A polarization beam splitter for splitting into two light beams with a polarization component is provided in a common optical path portion when processing both front and back surfaces of the disk, and is provided in two optical paths branched by the polarization beam splitter. Since the laser power adjusting means for adjusting the powers of the laser beams incident on the objective lenses provided in the component optical path and the S-polarized component optical path respectively to be equal to each other is provided, a simple optical configuration is adopted and a laser light source is used. Even if the characteristic of the means for branching the laser beam changes due to heat or other external influences, it is possible to form uniform bumps on both the front and back surfaces of the disk.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a processed area of a magnetic disk.

FIG. 2 is an explanatory diagram showing an example of bumps formed by texture processing.

FIG. 3 is a configuration diagram of an optical system of a laser texture device showing an embodiment of the present invention.

FIG. 4 is an operation explanatory view of laser power adjusting means.

FIG. 5 is a configuration diagram of an optical system of a laser texture device according to a conventional technique.

[Explanation of symbols]

10 disk 10C CSS
Area 10D Data recording area 11 Bump 12 Spindle means 13 Laser light irradiation means 14 Common optical path portion 15P P polarized light optical path portion 15S S polarized light optical path portion 20 Laser light source 21 Isolator 22 ND filter 23 Beam expander 24 First polarized beam splitter 26P, 26S λ / 2 wavelength plates 27P, 27S Second polarization beam splitters 28P, 28S Objective lens units 29P, 29S Beam samplers 30P, 30S Power detectors 31P, 31S Rotation drive means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masatoshi Soto             Hitachi Electronics, 3-16-3 Higashi, Shibuya-ku, Tokyo             Engineering Co., Ltd. F-term (reference) 4E068 AH00 CA05 CC00 CD04 CD08                       CK01 DA12                 5D112 AA27 GA17

Claims (4)

[Claims] 1. A disk is mounted on a spindle, and while the disk is rotated by the spindle, laser pulses from a laser light irradiation means including a laser light source and an objective lens are applied to both sides of the disk at a predetermined pitch interval. In a laser texture device that forms regular projections on both front and back surfaces of a disk over a predetermined range, one laser light source and the polarization plane of linearly polarized laser light from this laser light source are rotated by 45 °. A polarization plane control means and a polarization beam splitter for splitting the output light from this polarization plane control means into two light fluxes of a P polarization component and an S polarization component are provided in a common optical path portion for processing both front and back surfaces of the disc, and It is provided in two optical paths branched by this polarization beam splitter, and these P-polarized component optical path and S-polarized component optical path are provided. The laser texture apparatus being characterized in that a configuration in which a laser power adjusting means for adjusting so that the power of the incident light to the objective lens is equal provided Re respectively. 2. The laser texture device according to claim 1, wherein the polarization plane control means is constituted by an isolator that blocks return light to the laser light source. 3. The laser texture device according to claim 2, wherein a beam expander is provided between the isolator and the polarization beam splitter. 4. The laser power adjusting means has λ / 2 in the P polarization component optical path and the S polarization component optical path, respectively.
A wavelength plate and a second polarization beam splitter are provided, and a power detector is arranged between each of the second polarization beam splitters and the objective lens, and the P polarization component and S detected by these power detectors and S 2. The laser texture device according to claim 1, wherein the polarization azimuth vector by the λ / 2 wavelength plate is changed so that the light of the polarization component has a predetermined power.