KR20070018990A - Disk-shaped recording medium, disk device, and method for manufacturing optical disks - Google Patents

Abstract

According to the present invention, an optical disk capable of rewriting an information signal is provided, and the guide grooves 81a for tracking control are formed on tracks of the rewritable regions where the information signals can be rewritten. The recording layer 83 for writing the information signal is stacked. In the recording layer 83, at least in the rewritable area of the information signal, the information signal can be rewritten by the light in the vicinity of the multi-beam, and the surface where the guide groove 81a is formed The recessed part 85a is formed in accordance with this.

Description

Disk-shaped recording medium, disk device, and method for manufacturing optical disks

The present invention relates to a disc-shaped recording medium for optically recording or reproducing an information signal by using light in a nearby place, and a disc device for recording or reproducing an information signal with respect to the disc-shaped recording medium. A method of manufacturing an optical disc as a recording medium.

This application claims priority based on Japanese Patent Application No. 2004-190250 for which it applied on June 28, 2004 in Japan, and this application is integrated in this application by reference.

2. Description of the Related Art [0002] In the past, studies have been made to increase the density and capacity of a magnetic recording medium and an optical recording medium, and a recording medium having a high density and a large capacity has been provided. Among the recording media of this kind, a DVD (Digital Versatile Disc) is provided in the optical recording media, and further development of the next generation DVD having a recording density of several times or more of the DVD is in progress. On the other hand, the recording density of the hard disk magnetic recording device (HDD) is also increasing year by year. However, with the digitization, high definition, and high speed of optical communication of image information, further increase in storage capacity and high density are required, and in 2010, a recording density of ¹ Tbits / (inch) ² is expected.

In the hard disk magnetic recording apparatus, optical assist magnetic recording is expected because the superparamagnetism effect and the difficulty in controlling the gap width of the magnetic head are 100 to 300 Gbpsi and exceed the limit.

In the optical recording medium, optical recording using light in the vicinity of the place is expected to improve the recording density. Light in this vicinity is non-propagating light which exists in the area below the diffraction limit of light around a micro aperture or a micro object. If another object is brought close to the micro-opening or a distance below the diffraction limit of the micro-object, the light in the proximate location propagates within the object and causes interaction. In order to exude light in such an adjacent place, it can be realized by making the size of a micro opening and a micro object smaller. In addition, high-density optical recording can be performed by irradiating the optical recording medium with the light of the exhaled adjacent place. In optical recording using light in the vicinity of a place, a single light spot is followed by a guide groove (groove) or a weir (land) in the same manner as a DVD or the like to record or reproduce information.

In order to record information on the optical recording medium using the above-mentioned light of the adjacent place, it is necessary to perform this on a smooth rewritable area in which no groove is formed. In particular, in order to record information at a high density, It is necessary to increase the area of the smooth rewritable area.

In the conventional optical recording medium, the recording area recorded on the optical recording medium is formed along the groove, and one guide groove is formed so as to correspond to the optical spot caused by the light in the vicinity. For this reason, when a large number of optical spots are formed on the optical recording medium so that the recording density can be improved, the number of grooves corresponding to the formed optical spots is required. In reality, it is not easy to cut grooves corresponding to a large number of light spots in a spiral type at a fine pitch.

Usually, in order to form two grooves in parallel on an optical recording medium, it is necessary to realize this by using two beams when cutting or by wobbling an optical beam for high speed cutting, but the necessary grooves are required. As the number increases to three or four, there is a problem that the difficulty of production is added.

In order to solve this problem, Japanese Patent Application Laid-Open No. 2003-272176 and the like have proposed an optical recording medium, a recording / reproducing apparatus, etc. which aim to increase the density of optical recording and improve the transmission rate using light in the vicinity. This publication discloses a control method by a sliding or floating slider mounted on a swing arm. In this conventional example, since the objective lens is driven by imitating the surface of the optical recording medium, it is expected that such an objective lens will be inclined or displaced with respect to the optical axes arranged independently. In particular, in the case of recording and reproduction by light in the vicinity of the place, the position of the objective lens with respect to the surface of the optical recording medium and the light spot of the light in the vicinity of the place is strictly required. It may be considered to be a barrier to doing this.

In one step of the recording / reproducing process, a recess may be formed on the surface of the optical recording medium. If such a recess is formed, it becomes a barrier in the case of performing the recording / reproducing process by the light of the adjacent place.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-described problems, and an object thereof is to provide a high-density recording of an information signal in a disk-type recording medium capable of recording and reproducing by light at a nearby place. The present invention provides a disk-type recording medium capable of performing various processes following the effective use of the recess formed on the surface, and when such a disk-type recording medium is inserted, a high-density recording process of the information signal is provided. It is to provide a stable and executable disk device.

According to the present invention, in a disc-shaped recording medium in which guide grooves for tracking control are formed on tracks of a rewritable area in which information signals can be rewritten, recording layers for writing information signals are stacked on a substrate on which guide grooves are formed. The recording layer is capable of rewriting the information signal at least in the rewritable area by the light in the vicinity of the multi-beam, and at the position where the guide groove is formed on the outermost surface of the disc-shaped recording medium. A recess is thus formed.

In addition, the present invention provides a disk apparatus for recording or reproducing information on a disc-shaped recording medium having guide grooves for tracking control in tracks of a rewritable area in which information signals can be rewritten, the proximity of which is an information signal. And a control unit having a biaxial actuator for exhaling the light of the place into a multi-beam rewritable area, and a drive control unit for moving the biaxial actuator to a desired track position. In the case where a disc-like recording medium having a recessed portion formed on the surface of the recording layer for recording the information signal in at least the rewritable area and having the guide groove formed thereon is inserted in the vicinity, Through the drive control unit, the biaxial actuators are arranged so that the spot rows caused by the light of the place are arranged along the recesses. It controls the emitter.

In the disc-shaped recording medium according to the present invention, a recording layer is laminated on a substrate on which guide grooves are formed to write an information signal, and the recording layer is formed at least in the rewritable area of the light near a multi-beam. It is possible to rewrite the information signal, and since the recess is formed on the surface in accordance with the position where the guide groove is formed on the outermost surface, when the information signal is rewritten by light in the vicinity of the multi-beams, By forming a plurality of light spots of light in the vicinity, high density recording processing can be realized. In other words, when reproducing and recording using light in the vicinity of the place, the distance (air layer) on the surface of the disc from the lens that condenses the light beam influences the intensity of the signal. For this reason, when the guide groove is concave and the protective film is formed in the shape along this groove, the thickness of the air layer becomes thick, and the signal of the guide groove can be easily obtained. Further, by making the recording surface convex and guiding grooves for the multi-beams at predetermined intervals, the recording portion can be formed wider at a position closer to the lens, and the recording surface can be easily formed at a nearby place. For this reason, the present invention is useful when applied to an optical disc that reproduces or records information at a nearby location using a multi-beam.

Another object of the present invention, the specific advantages which can be obtained by the present invention will become more apparent from the embodiments described below with reference to the drawings.

Fig. 1 is a block circuit diagram showing an optical recording device to which the present invention is applied.

2 is a side view showing a lens block included in the optical recording device.

3 is a characteristic diagram showing the relationship between the amount of returned light and the distance between gaps.

4 is a partial sectional view showing an optical disc in which signals are recorded by the optical recording apparatus to which the present invention is applied.

Fig. 5 is a cross-sectional view showing an example in which light in a vicinity of a multi-beam is extruded from the signal recording surface in the lens block mounted in the optical recording device to which the present invention is applied.

FIG. 6 is a view showing a light spot formed by light in the vicinity of the lens block in the D direction in FIG. 5.

7 is a plan view showing an optical disc formed by meandering a guide groove.

8 is a plan view showing an example in which four optical spots are formed on an optical disc at one time.

9A to 9G are sectional views showing the manufacturing process of the optical disc in the order of process, FIG. 9A shows the state of polishing and cleaning the surface of the glass disc, and FIG. 9B shows the application of photoresist to the surface of the cleaned glass disc. 9C shows a state in which a laser light modulated with groove information is irradiated onto the photoresist and a groove pattern is recorded, FIG. 9D shows a state in which a glass disc is developed, and FIG. 9E shows a state of the glass disc. Fig. 9F shows a state in which a disk substrate is formed by a stamper constituted by a nickel plating layer, and Fig. 9C shows an optical disc on which a recording layer and a protective film are formed.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail, referring drawings.

First, a disk device to which the present invention is applied will be described. As shown in Fig. 1, the optical recording device 1 is a device that allows the optical disk 2 to be detachable as a recording medium. The optical recording device 1 includes a spindle motor 3 for rotationally driving the detachable optical disk 2, and an optical disk. The return light detected by the optical head 4 and the optical head 4 which irradiate the laser light onto the signal recording surface 2a of (2) and detect the return light reflected from the signal recording surface of the optical disc 2. and equipped with a control gap (6) for generating a respective control signal (S ₁₎ based on.

The spindle motor 3 is integrally mounted with a disk table on which the optical disk 2 is mounted. The spindle motor 3 uses the drive shaft as a linear velocity constant (CLV: Constant Linear Velocity) or an angular velocity constant (CAV: Constant Angular Velocity) based on a spindle drive signal supplied from a system controller (not shown). By rotating driving, the optical disk 2 mounted on the disk table is rotated.

The optical head 4 focuses a light beam on each recording layer of the optical disc 2 that is rotated by the drive of the spindle motor 3, and detects the return light reflected from the signal recording surface 2a of the optical disc 2. To a signal processor (not shown). At this time, the optical head 4 is controlled to emit laser light having a wavelength optimal for the optical disk 2 by the type of the optical disk 2 to be rotated.

Moreover, the gap control part 6 generates the control signal S based on the gap error signal GE transmitted from the optical head 4, and outputs this to the optical head 4. That is, by this control signal S ₁ , the objective lens of the optical head 4 can be finely adjusted in the direction to be separated from the optical disk 2.

In the optical recording apparatus 1, the optical head 4 is transported in the radial direction of the optical disk 2 by an access mechanism (not shown), and the optical head 4 is provided with a predetermined position of the optical disk 2. The movement is controlled to be located on the recording track.

Next, the optical head 4 used for the optical recording device 1 to which the present invention is applied will be described in more detail.

As shown in FIG. 1, the optical head 4 includes an APC (Automatic Power Controller) 42 for controlling a driving current of a semiconductor laser capable of emitting a multi-beam laser beam, and a holder for supporting each semiconductor laser ( 43, a beam splitter 44 disposed in an optical path of a multi-beam laser beam emitted from the semiconductor laser, a collimator lens 45 which uses the laser beam transmitted through the beam splitter 44 as parallel light, and A mirror 46 disposed in the optical path of the laser light that becomes parallel light by the collimator lens 45, a quarter wave plate 47 to which the laser light reflected by the mirror 46 is incident, and The lens block 38 which condenses the laser beam which passed the 1/4 wave plate 47 on the signal recording surface 2a of the optical disk 2, and returned by reflecting back from the signal recording surface 2a of the optical disk 2 And a light collecting element 55 for collecting light and a light receiving element 56 for receiving the return light. .

The holder 43 is equipped with a semiconductor laser 71 that emits a multi-beam laser beam having a predetermined wavelength. This semiconductor laser 71 is a light emitting element utilizing recombination light emission of a semiconductor. The semiconductor laser 71 emits laser light based on the information signal supplied from the information source 58 after the drive current is controlled by the APC 42 so that the output of the laser light is constant.

The beam splitter 44 transmits the laser light emitted from the semiconductor laser 71 and guides it to the optical disc 2, and at the same time, reflects the return light reflected from the optical disc 2 to the light receiving element 56. The laser light, which is the divergent light transmitted through the beam splitter 44, becomes parallel light by the collimator lens 45, and passes through the 1/4 wave plate 47. In addition, when the laser beam emitted from the semiconductor laser 71 has polarized light, the beam splitter 44 uses the polarization beam splitter to return the return light reflected from the optical disk 2 to the semiconductor laser 71. You can prevent the return.

The mirror 46 folds the optical path by reflecting the laser beam transmitted through the beam splitter 44. As a result, the laser beam is irradiated substantially perpendicularly to the signal recording surface 2a of the optical disc 2 located below the optical head 4.

The 1/4 wave plate 47 provides a phase difference of π / 2 to the laser beam passing through. The linearly polarized laser light emitted from the semiconductor laser 71 passes through the 1/4 wave plate 47 and becomes circularly polarized light. Moreover, when the circularly polarized laser beam which reflects and returns the optical disk 2 passes through this 1/4 wave plate 47, it becomes linearly polarized light.

The lens block 38 is arranged in the optical path of the laser beam which reflected the mirror 46, and has a function which condenses this laser beam and irradiates it on the signal recording surface 2a of the optical disc 2. As shown in FIG. The lens block 38 is supported by the biaxial actuator provided by the lens block 38 so as to be movable in the biaxial direction in the direction in which the optical disk 2 is close to the optical disk 2 and in the radial direction of the optical disk 2. Then, the lens block 38 is moved by the biaxial actuator based on the control signal S ₁ generated by the return light from the optical disc 2, and focusing control is realized.

Each laser beam condensed on the signal recording surface 2a of the optical disc 2 is reflected by this signal recording surface 2a and becomes parallel light by passing through the lens block 38. The return light reflected from the optical disk 2 returns to the focused light by passing through the collimator lens 45 through the 1/4 wave plate 47 and reflects the beam splitter 44.

The light receiving element 56 reflects the beam splitter 44, receives the laser beam focused by the condenser lens 55, photoelectrically converts it, and generates a gap error signal GE, which will be described later. It supplies to (6). In other words, by producing a number of detection patterns corresponding to the light spots of the laser beam of the multi-beams on the light receiving element 56, it is possible to acquire them as independent signals, respectively. By optimizing the detection pattern formed on the light receiving element 56, it is also possible to read the optical spot based on the push-pull method, for example.

Next, the details of the lens block will be described in more detail. The lens block 38 is disposed in the optical path of the laser beam that reflects the mirror 46, and as shown in FIG. 2, the objective lens 62, the SIL (Solid Immersion Lens) 63, and the lens folder 64 are provided. And a biaxial actuator (65).

The objective lens 62 is an aspherical lens having a function of condensing laser light and supplying it to the SIL 63. The SIL 63 is a high refractive index lens in which a part of a spherical lens is cut out in a plane. The SIL 63 is disposed close to the signal recording surface 2a, and enters the laser light supplied from the objective lens 62 from the spherical side and focuses on the central portion of the surface (cross section) opposite to the spherical surface.

In addition, in this lens block 38, a SIM (Solid Immersion Mirror) in which a reflection mirror is formed may be used as a replacement for the above-described SIL 63.

The lens folder 64 holds the objective lens 62 and the SIL 63 in a predetermined positional relationship. The SIL 63 is held by the lens folder 64 so that the spherical side faces the objective lens 62 and the surface opposite to the spherical surface (cross section) faces the signal recording surface 2a of the optical disc 2. do.

Thus, by arranging the high refractive index SIL 63 between the objective lens 62 and the signal recording surface 2a by the lens folder 64, the numerical aperture larger than the numerical aperture of the objective lens 62 alone ( NA) can be obtained. In general, since the spot size of the laser light irradiated from the lens is inversely proportional to the numerical aperture NA of the lens, the objective lens 62 and the SIL 63 can produce a laser beam having a smaller spot size. .

The biaxial actuator 65 operates the lens folder 64 in the focusing direction in accordance with the control voltage output from the gap control section 6 as the control signal S ₁ .

The evanescent light defined in the lens block 38 is light incident on the cross section of the SIL 63 at an angle equal to or greater than the critical angle and extruded from the reflection boundary surface of the laser light totally reflected. When the cross section of the SIL 63 is in the near field (near place) described later on the signal recording surface 2a of the optical disk 2, the above-described evanescent light extruded from the cross section of the SIL 63 is The signal recording surface 2a is irradiated.

Next, the near field will be described. Generally, as shown in FIG. 2, when the near field is d, the distance (gap) from the end surface of the SIL 63 to the signal recording surface 2a in the optical disc 2 is set to d. The area defined by d ≦ λ / 2 is determined by the wavelength λ of the incident laser light. That is, the gap d defined by the distance between the signal recording surface 2a of the optical disc 2 and the cross section of the SIL 63 satisfies d ≦ λ / 2, and is evaded from the cross section of the SIL 63. The state in which the centrifugal light is extruded on the signal recording surface 2a of the optical disc 2 is called a near field state. The gap d satisfies d > The state where no evanescent light is exuded is called a far field state.

By the way, in the far field state, all of the laser beams incident on the cross section of the SIL 63 at an angle greater than or equal to the critical angle are reflected to become the return light. Therefore, as shown in FIG. 3, the return light amount in a far field state becomes a fixed value.

On the other hand, in the near field state, a part of the laser light incident on the cross section of the SIL 63 at an angle greater than or equal to the critical angle is an optical disk (e. Extrudes to the signal recording surface 2a of 2). Therefore, as shown in FIG. 3, the return light amount of the totally reflected laser beam is reduced more in the far field state. In addition, the amount of returned light in this near field state decreases depending on the distance between the end surface of the SIL 63 and the disk 2.

In the near-field state, the returned light amount can be classified into a linear region that changes linearly with respect to the gap length and a nonlinear region that changes nonlinearly. Therefore, when the position of the cross section of the SIL 63 is in the near field state and belongs to the linear region, the amount of returned light is received by the light receiving element 56 to photoelectrically convert and generate a gap error signal GE. By performing feedback servo based on this, it becomes possible to control a gap constantly. That is, as shown in FIG. 3, when control is made so that the return light amount may become the control target value P, the gap d can be maintained at a constant distance.

Incidentally, the combination of the objective lens 62 and the SIL 63 constituting this lens folder forms a high NA state of NA = 1.83, but the present invention is not limited to this case, and the NA is 1.0 or more. In this case, it is possible to exhale the light of the adjacent place.

Since the gap d in the lens block 38 having the above-described structure is brought close to the signal recording surface 2a until it becomes λ / 2 or less, a dam (land: Land) is provided as a substitute for this guide groove. If there is a possibility of colliding with this at the time of scanning, the effect of the present invention becomes more remarkable by making the guide groove concave.

As described above, in the optical recording apparatus 1 to which the present invention is applied, the focus control can be performed by using the biaxial actuator 65, so that the optical recording apparatus 1 can be applied to light in the near place where the position of the objective lens with respect to the optical spot is strictly required. In recording and reproducing, it is possible to realize a more reliable process.

Next, a detailed configuration of the optical disc 2 for recording the information signal by the optical recording device 1 to which the present invention is applied will be described.

As shown in Fig. 4, the optical disk 2 is more simply stacked with at least a recording layer 83 on the substrate 81 on which the guide grooves 81a are formed.

The substrate 81 is made of polycarbonate, for example. The guide groove 81a formed in the substrate 81 can be easily cut to a width of nanometer size by exposing, for example, using an electron beam or the like. That is, this board | substrate 81 can be easily manufactured using the mastering apparatus of image development.

In addition, the recording layer 83 is made of a phase change recording film made of a material such as GeSbTe, and when made of a magneto-optical recording film, for example, it is made of a material such as TbFeCo.

On the outermost surface of this optical disc 2, a minute recess 85a is further formed depending on the position where the guide groove 81a is formed. In particular, the layer up to the outermost surface of the optical disc 2 is formed by using a solid or inorganic film such as a diamond like carbon (DLC) film or an ultraviolet curable resin, thereby using a resistor or the like. Compared with the case, the recessed part 85a can be formed efficiently.

In addition, in the case of performing high density optical recording using light in the vicinity of the place, it is preferable to increase the area of the flat portion by reducing the area of the recess 85a as much as possible, but the optical recording apparatus 1 using the multi beam 1 ) Is advantageous in that the ratio of the guide groove 81a to the number of light spots to be formed can be reduced as much as possible, and it is also possible to increase the recording density.

Incidentally, the size of the recess 85a is, for example, 30 nm in depth and about 80 nm in width, but is not limited to this size.

That is, in the optical recording apparatus 1 to which the present invention is applied, in addition to being capable of realizing the recording process by forming an optical spot of light in the vicinity of the optical disk 2 having the recessed portion 85a formed on the surface thereof, Various operations following the concave portion 85a can be executed. Acquisition of the guide track signal using this recessed portion 85a can also be realized. In particular, the merit comes from forming the recess 85a in accordance with the position of the guide groove 81a described above.

The optical disc 2 having such a configuration will be described with respect to the case where the optical recording device 1 irradiates light in the vicinity of a multi-beam.

FIG. 5 shows an example in which the lens block 38 having the above-described configuration exudes light at a location close to the multi-beam to the signal recording surface 2a. Based on the first laser light L1 indicated by the solid line among the laser beams of the multi-beams, the light in the vicinity is irradiated to the point p on the signal recording surface 2a. Moreover, based on the 2nd laser beam L2 shown with the dotted line among the laser beams of this multi-beam, the light of the near place is irradiated to the point q on the signal recording surface 2a.

)는 어떠한 값이어도 좋다. 이러한 경우에는 각도(

)를 미리 식별해 둠으로써, 각 광스포트(Sp)의 거리를 취득하는 것이 가능하게 되며, 후단의 신호 처리에 있어서의 유리성을 확보할 수 있다.FIG. 6 shows the light spot Sp formed by the light in the vicinity of the lens block in the D direction in FIG. 5. As shown in FIG. 6, each optical spot Sp of a multi-beam is arrange | positioned so that the guide groove 81a perpendicular | vertical to the disc advancing direction A of the optical disc 2 may be pinched | interposed. Angle with respect to the guide groove (81a) of the straight line connecting the center (P ₁₎ of the light spot (Sp) (

May be any value. In this case, the angle (

By identifying () in advance, it is possible to obtain the distance of each light spot Sp, and the advantage in the signal processing of the next stage can be ensured.

In FIG. 6, when the distance in the radial direction B of the optical disc 2 between each optical spot Sp of the multi-beams is d, the width of the guide groove 81a is d or less. As a result, the tracking information can be detected from the change in the amount of light based on the positive light spot Sp. Such tracking information can also be obtained by detecting a push-pull signal, for example.

In addition, this guide groove 81a may be formed meandering as shown in FIG. In other words, the guide groove 81a is executed on the basis of information such as a clock, an address, and the like, so that the light spot train SL is formed of two light spots Sp formed to cover the guide groove 81a. Signal detection can also be performed. In other words, the tracking as described above is realized by calculating the crossover with the guide groove 81a of the return light by using these two light spots Sp and giving it to the biaxial actuator 65 as an error signal.

By following the optical spot Sp in the guide groove 81a in this manner, for example, in the case where the guide groove 81a is drawn in a spiral shape, after the optical disc 2 has been circulated for one week, Figs. The light spot string SL is moved from the position indicated by the solid line at 7 to the position indicated by the dotted line.

In addition, the pitch between the guide grooves 81a may be controlled to be n × d in the case of forming an optical spot train composed of n light spots. As a result, even when a straight line connecting the center P ₁ of the optical spot Sp to be formed is perpendicular to the guide groove 81a, the irradiation positions of the optical spot Sp do not overlap each other. This makes it possible to efficiently perform the recording / reproducing process on the optical disc 2.

8 shows an example in which four optical spots Sp are formed on the optical disc 2 at one time. As shown in Fig. 8, two light spots Sp are formed on both sides with the guide grooves 81a sandwiched therebetween. In the case where the guide groove 81a is drawn in a spiral shape, after the optical disk 2 has been circulated for one week, the light spot Sp moves from the position indicated by the solid line shown in FIG. 8 to the position indicated by the dotted line. The number of light spots Sp formed on both sides of the guide groove 81a is preferably in a ratio of 1: 1, but is not limited to this and may be configured in any ratio. For example, one light spot Sp on one end side of the guide groove 81a and three light spots Sp on the other end side may be configured in a ratio of 1: 3. In addition, as long as the optical spot Sp is formed along the guide groove 81a, four light spots Sp may be arranged only on one end side of the guide groove 81a. In addition, as long as the number of this light spot Sp is two or more, what kind of thing may be sufficient as it.

Similarly in the case where four optical spots Sp are formed on the optical disc 2 at the same time, by controlling the interval of the guide grooves 81a more than 4d, i.e., four spot intervals in the formula of n × d, The irradiation positions of the optical spots Sp do not overlap with each other, and the recording / reproducing process on the optical disc 2 can be efficiently performed.

Next, a manufacturing process of an optical disc for recording according to the present invention will be described.

In manufacturing the optical disc 2 to which the present invention is applied, as shown in FIG. 9A, the glass master 101 is prepared, and the surface of the glass master 101 is polished and washed. Next, as shown to FIG. 9B, the photoresist 102 is apply | coated to the surface of the cleaned glass disk 101. FIG. Next, as shown in FIG. 9C, the laser light 103 modulated with groove information is collected by the objective lens 104, irradiated onto the photoresist 102, and the groove pattern is recorded. In this case, it is also possible to use the light of the near place as a laser beam irradiated to the photoresist 102.

After exposing and recording the groove pattern as described above, as shown in FIG. 9D, the glass master 101 is developed. At this time, for example, only the photoresist 102 of the portion to which the laser light is irradiated is dissolved by the developer. As a result, a pattern corresponding to the pattern formed on the recording surface is formed on the glass master 101.

Next, as shown in FIG. 9E, nickel is deposited on the surface of the glass master 101 on which the pattern is formed on the surface to form a nickel plating layer 117. Thereafter, the nickel plating layer 117 is separated from the glass master 101 so that the uneven pattern formed on the glass master 101 is transferred to the nickel plating layer 117. The nickel plating layer 117 to which the uneven pattern is transferred is used as a stamper for forming the disk substrate constituting the optical disk.

The stamper 127 formed of the nickel plating layer 117 is attached to, for example, a mold apparatus for injection molding, and the synthetic resin material is molded using the mold apparatus. When the synthetic resin material is molded, as shown in FIG. 9F, the disk substrate 112 on which the groove pattern 112a, which is an uneven pattern formed on the surface of the stamper 127, is transferred is formed.

A recording film 105 is formed on the surface on which the groove pattern 112a of the disk substrate 112 is formed, and the recording film 105 is covered and the transparent protective film 106 is deposited to form a film as shown in Fig. 9G. An optical disk 107 for recording is formed.

In the optical disk 107, the recording layer 105 is formed using a material which enables the recording of the information signal by irradiation of the light beam or the rewriting of the information signal. For example, the recording layer 105 is composed of a phase change recording film made of a material such as GeSbTe or a magneto-optical recording film made of a material such as TbFeCo.

In addition, the protective film 106 is preferably formed of a solid or inorganic film such as a diamond like carbon (DLC) film or the like. The protective film 106 may be formed of an ultraviolet curable resin.

Note that the present invention is not limited to the above-described embodiments described with reference to the drawings, and that various changes, substitutions, or equivalents thereof can be made to those skilled in the art without departing from the scope of the appended claims and their known features. Is obvious.

In addition, in the optical recording apparatus 1 to which the present invention is applied, an example in which a signal can be recorded on the basis of two modes, a near field and a far field, has been described. The present invention is not limited to this, and may be applied to a device capable of recording a signal by light in a nearby place based on the mode of the near field only. It is a matter of course that the optical recording device 1 to which the present invention is applied may adopt a configuration capable of reproducing a signal recorded on the optical disc 2.

Claims (7)

In a disc-shaped recording medium in which guide grooves for tracking control are formed in tracks in a rewritable area where information signals can be rewritten, On the substrate on which the guide groove is formed, a recording layer is stacked to write the information signal, The recording layer is capable of rewriting the information signal by light in the vicinity of the multi-beam in at least the rewritable area, A disc shaped recording medium, characterized in that a recess is formed on the most surface of the disc shaped recording medium in accordance with the position where the guide groove is formed. The method of claim 1, The guide groove has a disc shape having a width less than or equal to the spot spacing d of light in the vicinity of the multi-beam, and having a pitch of d × n or more when the spot number n is used. Record carrier. The method of claim 1, A disc recording medium, characterized in that the layer until the most surface of the disc recording medium is made of a diamond like carbon (DLC) film. The method of claim 1, And the guide groove is formed by meandering. A disc apparatus for recording / reproducing a disc-shaped recording medium having guide grooves for tracking control in tracks of a rewritable area in which information signals can be rewritten. Control means having a two-axis actuator for causing light in the vicinity of the information signal as a multi-beam to be extruded into the rewritable region, and a drive control unit for moving the two-axis actuator to a desired track position. Equipped with The control means has a recording layer for writing the information signal on at least the rewritable area on the substrate on which the guide groove is formed, and is concave on the outermost surface according to the position where the guide groove is formed. When an additional disc-shaped recording medium is inserted, the biaxial actuator is controlled via the drive control unit so that the spot rows by the light of the adjacent place are arranged along the recessed portion. . The method of claim 5, The biaxial actuator in the control means includes an objective lens for condensing the supplied light and exuding the light in the adjacent place, and the aperture switch NA of the objective lens is 1.0 or more. Disk device. In the manufacturing method of an optical disc having a rewritable area by a multi-beam using light in the vicinity of the place, A guide groove for tracking control is formed on each of the tracks formed in the rewritable area, A recording layer is formed on the substrate on which the guide grooves are formed, for recording an information signal by light of a place close to the multi-beam in at least a rewritable area, And a concave portion is formed on the surface of the substrate according to the position where the guide groove is formed.

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