KR20090096047A - Optical disc - Google Patents

Abstract

An optical disc is provided to prevent loss of data by preventing contamination of each layer inside the optical disc and clearly mark a BCA(Burst Cutting Area) by adopting a structure in which a large amount of dye can be put. An optical disc includes a substrate(110), a reflecting layer(120), a cover layer and a coating layer. The substrate comprises a plurality of protrusions(112a,112b). The reflecting layer is located on the substrate. The cover layer and coating layer are located on the reflecting layer. The substrate comprises a burst cutting area and a data area. An interval between one side end of the first protrusion and one side end of the second protrusion is 1 to 3 micro meter. A recording layer(130) is formed between the reflecting layer and the cover layer. A dielectric layer is formed in at least one of a gap between the reflecting layer and the recording layer or a gap between the recording layer and the cover layer. The protrusion is made of a plurality of sub protrusions. An interval between one side end of the first sub protrusion and one side end of the second sub protrusion is 0.2 to 0.4 micro meter.

Description

Optical disc

The present invention relates to a storage medium, and more particularly to an optical disc.

With the advent of the multimedia era, which covers video signals, audio signals, and computer data information including moving and still images, package media such as CDs, DVDs, BDs, and various types of discs are already widely used. Attempts have been made to apply to recording media of telephones, digital cameras, broadcasts and movies.

This trend is likely to stand out in the next generation of media. In the next generation media, the size of the recording mark is getting smaller as the laser wavelength is shorter and the numerical aperture becomes larger for higher transmission speed and higher storage capacity.

Optical discs are largely read-only-memory (ROM), recordable (R) capable of recording information only once, and rewritable (Rewritable, Re capable of repeatedly writing, reading, and erasing information). ) There is a disk.

In general, an optical disc inserts a code into a burst cutting area (BCA) by irradiating a laser to a reflective layer or a recording layer positioned on a cover layer. In the BCA code, unique disc information, copy protection code, and the like are recorded.

In general, the reflective layer included in the optical disk is made of silver (Ag) alloy or the like. The characteristic of the reflective film made of silver prevents the structure and phase of the optical disk from changing even when a high-power laser is incident, thereby improving signal readability. Maintaining is a big purpose.

However, in general, the energy of the irradiated laser is so strong that the shape of the cover layer, the coating layer, and the reflective layer is deformed or the image is deformed after the BCA code is inserted, thereby changing the size or width of the BCA code.

1 is a diagram of marking a BCA code on a burst cutting region. In general, when marking a BCA code, an objective lens having a wavelength of 405, 650 or 850 nm and a numerical aperture (NA) of 0.6 to 1.0 or less is generally used. The energy is collected and recorded at a high energy density. Recently, a light source using a wavelength of 410 to 257 nm is also used.

Here, the marking was normally performed using an 8W laser of 810 nm wavelength. In FIG. 1, BCA codes are those which are formed by black lines, such as barcode shapes.

On the other hand, Figure 2 is a diagram showing that the BCA code is not clearly marked (left side view), or after the BCA code is marked, the BCA code is not recognized due to deterioration or contamination of the layers in the optical disc.

As a result, the BCA code may not be properly recognized by the optical pickup apparatus, or a defect may occur in which information cannot be read.

The problem to be solved by the present invention is to develop an optical disk structure that can contain a lot of dye, to clearly mark the BCA code, and to provide an optical disk that can prevent data loss by preventing the deterioration of each layer in the optical disk. have.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

According to an embodiment of the present invention, an optical disk includes a substrate including a plurality of protrusions, a reflective layer on the substrate, and a cover layer and a coating layer on the reflective layer, wherein the substrate includes a burst cutting area (BCA) and The interval between the one end of the first protrusion and the one end of the second protrusion of the plurality of protrusions including the data area Data and positioned in the burst cutting area may be 1 to 3 μm.

In addition, a recording layer may be further included between the reflective layer and the cover layer.

In addition, a dielectric layer may be further included between at least one of the reflective layer and the recording layer or between the recording layer and the cover layer.

In addition, the distance between one end of the first protrusion and one end of the second protrusion of the plurality of protrusions positioned in the burst cutting area of the substrate may be 2 μm.

In addition, the protrusion may include a plurality of sub protrusions.

In addition, the interval between one end of the first sub-projection and one end of the second sub-projection among the plurality of sub-projections positioned in the burst cutting region of the substrate may be 0.2 to 0.4 μm.

In addition, the interval between one end of the first sub-projection and one end of the second sub-projection among the plurality of sub-projections positioned in the burst cutting region of the substrate may be 0.32 μm.

In addition, the interval between one end of the first protrusion and one end of the second protrusion among the plurality of protrusions positioned in the data area of the substrate may be 1 to 3 μm.

In addition, the burst cutting area of the recording layer may be made of any of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based or Azo-based materials.

In addition, the Azo-based material may have a refractive index of 2.34 to 2.46 and a specific heat of 1.7 cal / g · ° C. The thermal conductivity may be 0.28 W / mk.

The burst cutting area of the reflective layer or the data area of the reflective layer may be formed of at least one of metal, organic material, and inorganic material.

In addition, the data area of the reflective layer may be made of at least one of silver (Ag), silver alloy, or dielectric material.

In addition, the burst cutting region of the reflective layer may include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based or Azo-based materials.

In addition, the reflectivity of the burst cutting region and the reflectance of the data region of the reflective layer may be different from each other.

In addition, the thickness between the top and bottom ends of the protrusions or sub-projections may be 35 to 200 nm.

In addition, the thickness between the top and bottom of the protrusion or sub-projection may be 35 to 70 nm or 120 to 180 nm.

Further, the thickness between the top and bottom ends of the protrusions or sub-projections may be 45 nm.

Also, the optical disc may be a BD-ROM.

Also, the optical disc may be a BD-R.

In addition, the coating layer may be a hard coating layer.

The optical disk according to an embodiment of the present invention has the effect of preventing the deterioration and contamination of the optical disk and preserving data without loss.

Details of the embodiments described below are included in the detailed description and drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

Hereinafter, an optical disc according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a plan view of an optical disk according to an embodiment of the present invention.

Referring to FIG. 3, the optical disc 100 may be a recordable Blu-ray disc or a playback-only Blu-ray disc, but is not limited thereto. That is, an optical disc such as a DVD may also fall within the scope of the present invention.

When proceeding from the clamping hole on the innermost inner circumferential surface of the optical disc 100 to the outer circumferential surface, the respective regions are examined: a clamping area 10, a burst cutting area BCA. 20 There may be a read-in zone 30, a data area 40, and a read-out zone 50. At this time, although there is a transition area between the clamping area 10 and the burst cutting area 20, it is noted that not shown.

In addition, it will be understood that the term 'data area' described in the future may be a term including a lead-in area and a lead-out area.

When the burst cutting area 20 is seated in the optical disc reproducing apparatus, the optical disc device is first accessed. The burst cutting area 20 may be a variety of information such as a disc serial number or encryption information for disc copy protection through the BCA code 25. Disc key information can be recorded.

The burst cutting area 20 may be located between 21.3 (+0.0, -0.3) and 22.0 (+0.2, -0.0) mm starting from the inner circumferential surface of the optical disk. In addition, the data areas 30, 40, and 50 may be located between 22.0 (+0.2, −0.0) and 60 mm.

4 through 5 are cross-sectional views of optical disks according to various embodiments of the present disclosure. 4 to 5 schematically illustrate the cross-sectional view taken along line II ′ of FIG. 3.

4 to 5, an optical disk according to an embodiment of the present invention includes a substrate 110, a reflective layer 120, a recording layer 130, and a dielectric layer 140. , A cover layer 150, and a coating layer 160.

 4 to 5 may be a Blu-ray disc-Recordable (BD-R).

Here, the dielectric layer 140 may be formed or removed depending on the function of the optical disk and the characteristics of the material between the other components.

The substrate 110 may be made of polycarbonate, but is not limited thereto. One surface of the substrate 110 may include a protrusion and a groove that are regularly patterned.

The reflective layer 120 may be positioned on the substrate 110. The reflective layer 120 may control the balance of absorption and reflection of the laser, absorption of heat, transmission, and emission by adjusting multiple reflection conditions in the recording layer 130.

The reflective layer 120 may be made of silver or a silver alloy. Representatively there may be AgPdCu (APC) and the like.

In particular, the burst cutting area A of the reflective layer 120 may include a material having good heat absorption and good reflectivity. The burst cutting region A of the reflective layer 120 may include at least one of silicon (Si), palladium (Pd), copper (Cu), or magnesium (Mg).

The data area B of the reflective layer 120 may be made of at least one of silver (Ag), silver alloy, or dielectric material.

The recording layer 130 may be positioned on the reflective layer 120. The recording layer 130 may be formed of a single layer or may be formed of more than two layers. Here, the case of forming a single layer is shown.

The materials constituting the recording layer 130 are mainly materials that absorb light, and the absorbed light energy is converted into thermal energy to generate heat, and also reacts to express optical contrast.

The recording layer 130 includes a first recording layer 130 including at least one selected from the group consisting of silicon (Si), germanium (Ge), and antimony (sb), silver (Ag), and antimony (Sb). , Bismuth (Bi), tellurium (Te), or titanium (Ti) may be made of a second recording layer 130 including any one or more selected from the group consisting of.

In addition, the recording layer 130 may be made of an organic material such as a dye.

Information may be recorded in the recording layer 130 through laser light having a wavelength of 405 nm and a numerical aperture of 0.8 to 1.0.

The dielectric layer 140 may be positioned on the recording layer 130. The dielectric layer 140 generally uses a material having a large optical refractive index. The desired contrast can be obtained by easily adjusting the multi-reflection conditions through the thickness adjustment of the dielectric layer 140.

 The dielectric layer 140 may be disposed between the recording layer 130 and the cover layer 150 to prevent damage to the plastic due to high temperature.

The dielectric layer 140 may also be made of ZnS-SiO ₂ (ZSSO) or TiO ₂ , but is not limited thereto.

In addition, the dielectric layer may be positioned between the recording layer 130 and the reflective layer 120 to adjust the speed at which heat is emitted from the recording film to the reflective layer 120 to adjust the recording power and the shape of the recorded mark.

Note that the dielectric layer located between the recording layer 130 and the reflective layer 120 is not shown.

The cover layer 150 and the coating layer 160 may be positioned on the dielectric layer 140.

The coating layer 160 may be a hard coating layer. The cover layer 150 may be attached using a transparent plastic sheet, or may be formed using a transparent adhesive (ultraviolet curable resin) or PSA (pressure sensitive adhesive), or only an ultraviolet curable resin as a layer.

4 and 5 may be divided into a burst cutting area A and a data area B. FIG.

In the burst cutting area A and the data area B according to FIG. 4, it can be seen that grooves positioned between the protrusions 112a and 112b and the protrusions 112a and 112b of the substrate 110 are all formed uniformly. .

On the other hand, the burst cutting area A according to FIG. 5 has a wide width of the groove between the protrusion 112a and the protrusion 112a, but between the protrusion 112b and the protrusion 112b in the data area B. FIG. The width of the groove can be seen that narrow.

Referring to FIG. 6, an optical disc 100 according to another embodiment of the present invention may be a BD-ROM.

The optical disk 100 according to another embodiment of the present invention may include a substrate 110, a reflective layer 120, a dielectric layer 140, a cover layer 150, and a coating layer 160. Here, the information to be reproduced may already be stored on the substrate 110.

Since the optical disc 100 according to another embodiment of the present invention is similar to the optical disc 100 according to the exemplary embodiment of the present invention, a stack structure and a material forming the components thereof will be omitted.

Hereinafter, the structure of the substrate 110 and the changed structure of the optical disk will be described in detail with reference to FIGS. 7 through 8.

7 to 8 are detailed views of FIGS. 4 to 5.

Referring to FIG. 7, one surface of the substrate 110 of the optical disk according to the exemplary embodiment of the present invention may be formed of protrusions 112a and 112b having a trapezoidal shape and grooves between the protrusions 112a and 112b. .

The optical disk may be divided into a burst cutting area A and a data area B. FIG. For convenience of description, the projection of the burst cutting area A is indicated by reference numeral 112a, and the projection of the data area B is indicated by reference numeral 112b. The data area B and the burst cutting area A may include a plurality of protrusions 112a and 112b.

The width between the one end X1 at which the first protrusion, which is one of the plurality of protrusions in the burst cutting area A, starts and the one end X2 at which the second protrusion closest to the first protrusion starts, is P1. May be referred to.

Among the plurality of protrusions in the data area B, a width between the one end X3 at which the first protrusion is started and the second one end X4 at which the second protrusion is started may be referred to as P2.

Here, the length of P1 and P2 according to an embodiment of the present invention may be 1 to 3㎛, preferably 2㎛.

The length of said P1 and P2 of a general optical disc is 0.32 micrometer. The optical disc according to the present invention has a width of the groove between the first and second protrusions of the burst cutting area A and the first of the data area B by widening the width between X1 and X2 or between X3 and X4. The width of the groove between the protrusion and the second protrusion can be widened.

Here, the thicknesses of the projections of the burst cutting region A and the data region B (between the uppermost and lowermost portions of the projections) may be 35 to 200 nm.

In particular, when the recording layer 130 to be described later is made of a dye, in the optical disk containing a dye for recording using a laser of 405nm, the thickness of the protrusion may be 35 to 70nm, preferably 45nm have.

In addition, in the optical disc including the dye for recording using a 650 nm laser, the thickness of the protrusion may be 120 to 180 nm.

Under the above-described structure, the reflective layer 120 may be positioned on the substrate 110 on which the protrusion and the groove are formed to form a step in the form of the protrusion and the groove.

The recording layer 130 made of dye may be disposed on the reflective layer 120.

The recording layer 130 may include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials, but is not limited thereto.

In addition, only the burst cutting area A of the recording layer 130 may include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials.

In addition, the burst cutting region A of the reflective layer 120 may also include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials.

In particular, the recording layer 130 may be formed to have a thickness of 10 nm or more using an Azo-based dye having a refractive index of 2.34 to 2.46, a specific heat of 1.7 cal / g · ° C, and a thermal conductivity of 0.28 W / mk. .

Since the recording layer 130 located on the substrate 110 having the above-described structure has a wide width of the groove between the protrusion and the protrusion of the substrate 110 described above, the volume of the dye material can be increased by the increased amount. have.

Therefore, in the present invention, the heat absorption can be increased by increasing the volume of the dye in the recording layer 130, and the modulation and the contrast can be increased. This can make the marking of the BCA code easier and clearer, and can prevent data loss by preventing deterioration and contamination of the cover layer 150 and the coating layer 160.

Referring to FIG. 8, in the substrate 110 including the burst cutting area A and the data area B, the width of the groove between the protrusion and the protrusion may be different from that of FIG. 7.

Except for further description here, since it is the same as that of FIG. 7, the characteristic of FIG. 8 is demonstrated.

Among the plurality of protrusions in the burst cutting area A of the optical disk according to the embodiment of the present invention, the width P1 between one end X1 at which the first protrusion is started and one end X2 at which the second protrusion is started is It may be 1 to 3㎛, preferably 2㎛.

The width P2 between one end X3 at which the first protrusion is started and the second one end X4 at which the second protrusion is started among the plurality of protrusions in the data area B may be smaller than the length of P1.

The optical disk according to the embodiment of the present invention can widen the width of the groove between the first protrusion and the second protrusion of the burst cutting area A by widening the width between X1 and X2.

Here, the thicknesses of the projections of the burst cutting region A and the data region B (between the uppermost and lowermost portions of the projections) may be 35 to 200 nm.

In particular, when the recording layer 130 to be described later is made of a dye, in the optical disk containing a dye for recording using a laser of 405nm, the thickness of the protrusion may be 35 to 70nm, preferably 45nm have.

In addition, in the optical disc including the dye for recording using a 650 nm laser, the thickness of the protrusion may be 120 to 180 nm.

Under the above-described structure, the reflective layer 120 may be positioned on the substrate 110 on which the protrusion and the groove are formed to form a step in the form of the protrusion and the groove.

The recording layer 130 made of dye may be disposed on the reflective layer 120.

The recording layer 130 may include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials, but is not limited thereto.

In addition, only the burst cutting area A of the recording layer 130 may include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials.

In addition, the burst cutting region A of the reflective layer 120 may also include at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based, or Azo-based materials.

In particular, the recording layer 130 may be formed to have a thickness of 10 nm or more using an Azo-based dye having a refractive index of 2.34 to 2.46, a specific heat of 1.7 cal / g · ° C, and a thermal conductivity of 0.28 W / mk. .

Since the recording layer 130 positioned on the substrate 110 having the above-described structure has a wide width of the groove between the protrusion and the protrusion of the burst cutting area A of the substrate 110, the dye material is increased by the amount of the dye. Can increase the volume.

Therefore, in the present invention, the heat absorption can be increased by increasing the volume of the dye in the recording layer 130 of the burst cutting area A, and the modulation and contrast can be increased. This can make the marking of the BCA code easier and clearer, and can prevent data loss by preventing deterioration and contamination of the cover layer 150 and the coating layer 160.

9 is a cross-sectional view of a substrate according to another embodiment of the present invention.

Referring to FIG. 9, the protrusion 112a of the substrate 110 in the burst cutting area A may include a plurality of sub protrusions 114a. The sub protrusions 114a may include 3 to 5 sub-projections 112a.

The width between the one end Y1 at which the first sub-projection is started and the one end Y2 at which the second sub-projection is started among the plurality of sub-projections 114a formed at one protrusion 112a position will be referred to as L1. Can be.

Herein, the length of L1 may be 0.2 to 0.4 μm, and preferably 0.32 μm.

In addition, the height of the sub protrusion may be equal to the height of the protrusion described above in one embodiment of the present invention.

An optical disc according to another embodiment of the present invention divides the protrusion into several sub protrusions to form grooves between the sub protrusions, thereby increasing the volume of the dye forming the recording layer when the recording layer is formed on the substrate 110. Can be.

Therefore, in the present invention, the heat absorption can be increased by increasing the volume of the dye in the recording layer, and the modulation and contrast can be increased. This makes marking of BCA codes easier and clearer, and prevents data loss by preventing deterioration and contamination of the cover layer and coating layer.

10 is a cross-sectional view of an optical disk according to another embodiment of the present invention. The optical disc according to FIG. 9 may be a BD-ROM.

Referring to FIG. 10, the optical disk according to this figure may include a substrate 210, a reflective layer 220, a dielectric layer 240, a cover layer 250, and a coating layer 260.

One surface of the substrate 210 of the data area B and the burst cutting area A may include a plurality of protrusions 112a and aa2b.

Among the plurality of protrusions 112a in the burst cutting area A, the width between one end X5 at which the first protrusion is started and one end X6 at which the second protrusion is started may be referred to as P3.

Among the plurality of protrusions 112b in the data area B, a width between the one end X7 at which the first protrusion is started and the second one end X8 at which the second protrusion is started may be referred to as P4.

Here, the length of P3 and P4 may be 1 to 3㎛, preferably 2㎛. The length of P3 may be the same or longer compared to the length of P4.

In addition, the height of the sub protrusion according to another embodiment of the present invention is the same as the height of the protrusion described above in one embodiment of the present invention.

According to another exemplary embodiment of the present invention, an optical disc includes a width of a groove between a first protrusion and a second protrusion of a burst cutting area, a width between a first protrusion of a data area, and a width between X5 and X6 or between X7 and X8. The width of the grooves between the second protrusions can be widened.

The reflective layer 220 may be positioned on the substrate 210. The material forming the reflective layer 220 may include an organic dye.

In addition, the dye material may be included only in the burst cutting area A of the reflective layer.

In another embodiment of the present invention, by adding a dye to the reflective layer 220 of the burst cutting region A and forming the reflective layer 220 on the substrate 210 having the above-described structure, the reflective layer Since the ratio of the dye on the 220 may be increased, heat absorption may be increased, and modulation and contrast may be increased. This makes marking of BCA codes easier and clearer, and prevents data loss by preventing deterioration and contamination of the cover layer and coating layer.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1 to 2 show burst cutting regions of an optical disc.

3 is a plan view of an optical disk according to an embodiment of the present invention.

4 to 6 are cross-sectional views of an optical disk according to an embodiment of the present invention.

7 to 8 are detailed views of FIGS. 4 to 5.

9 is a cross-sectional view of a substrate according to another embodiment of the present invention.

10 is a cross-sectional view of an optical disk according to another embodiment of the present invention.

Claims (20)

A substrate including a plurality of protrusions; A reflective layer on the substrate; And A cover layer and a coating layer on the reflective layer, The substrate includes a burst cutting area BCA and a data area, and a distance between one end of a first protrusion and one end of a second protrusion of the plurality of protrusions positioned in the burst cutting area is 1 to 1. 3 μm optical disc. The method of claim 1, And a recording layer between the reflective layer and the cover layer. The method of claim 2, And a dielectric layer between at least one of the reflective layer and the recording layer or between the recording layer and the cover layer. The method according to any one of claims 1 to 3, And an interval between one end of the first protrusion and one end of the second protrusion of the plurality of protrusions positioned in the burst cutting area of the substrate is 2 μm. The method according to any one of claims 1 to 3, And the protruding portion includes a plurality of sub-projecting portions. The method of claim 5, wherein The distance between the one end of the first sub-projection portion and the one end of the second sub-projection portion of the plurality of sub-projections located in the burst cutting region of the substrate is 0.2 to 0.4㎛. The method of claim 6, And an interval between one end of the first sub-projection and one end of the second sub-projection of the plurality of sub-projections positioned in the burst cutting area of the substrate is 0.32 μm. The method according to any one of claims 1 to 3, And an interval between one end of the first protrusion and one end of the second protrusion of the plurality of protrusions positioned in the data area of the substrate is 1 to 3 μm. The method of claim 2 or 3, And the burst cutting region of the recording layer comprises at least one of squarylium, croconium, cyanine, phthalocyanine or Azo materials. The method of claim 9, The Azo-based material has a refractive index of 2.34 to 2.46, a specific heat of 1.7 cal / g 占 폚, and a thermal conductivity of 0.28 W / mk. The method according to any one of claims 1 to 3, And the burst cutting region of the reflective layer or the data region of the reflective layer is formed of at least one of metal, organic material and inorganic material. The method of claim 11, And the data area of the reflective layer is made of at least one of silver (Ag), silver alloy or dielectric material. The method of claim 11, The burst cutting region of the reflective layer comprises at least one of squarylium-based, croconium-based, cyanine-based, phthalocyanine-based or Azo-based materials. The method according to any one of claims 1 to 3, And the reflectivity of the burst cutting region and that of the data region of the reflective layer are different from each other. The method according to any one of claims 1 to 3 or 5, And a thickness between an upper end and a lower end of the protruding portion or the sub-protruding portion is 35 to 200 nm. The method of claim 15, And the thickness between the top end and the bottom end of the protrusion or sub-projection is 35 to 70 nm or 120 to 180 nm. The method of claim 16, And the thickness between the top end and the bottom end of the protrusion or sub-projection is 45 nm. The method of claim 1, And the optical disc is a BD-ROM. The method of claim 2 or 3, And the optical disc is a BD-R. The method of claim 1, The coating layer is an optical disc, characterized in that the hard coating layer.

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