CN101053028B - Multi layer disc - Google Patents

Abstract

A multi-layer disc is disclosed which includes a plurality of recording layers, as in a dual layer blu-ray disc. In the multi- layer disc, the tolerance of a transparent substrate thickness from a surface of a cover layer to each recording layer is set to be different from those of transparent substrate thicknesses to other recording layers within a range in which no degradation in the characteristics of recording and reproduction signals for each recording layer occurs. Accordingly, it is possible to more efficiently manufacture multi -layer discs, to achieve an improvement in the manufacturing yield of multi-layer discs, and to achieve a reduction in the manufacturing costs of multi-layer discs.

Description

Multiplayer optical disk

Technical field

The present invention relates to multiplayer optical disk, and more specifically say and relate to wherein the multiplayer optical disk that in the CD tolerance of the thickness from tectal surface to each recording layer is set to be different from the thickness deviation of other recording layer.

Background technology

High density compact disc can write down or reproduce a large amount of high-quality videos and voice data such as Blu-ray Disc (BD), and this high density compact disc develops gradually, and expects that it can put it into commercial operation.Usually, this CD has wherein to form a plurality of recording layers on single optical disc substrate, with the sandwich construction of the increase that realizes recording capacity.

With reference to figure 1, show simple layer BD100.Individual layer BD100 has the compact disk structure of lamination, comprises substrate 10, recording layer 11 and overlayer 12.

Typically, the individual layer BD100 with above-mentioned compact disk structure has the gross thickness of 1200 μ m.When the radial position corresponding to 22 to 23mm radius was set to the reference position, overlayer 12 for example had therein, and under the situation of 1.6 refractive index, overlayer 12 has the thickness of 100 μ m.Because overlayer 12 has ± thickness deviation of 5 μ m, from the surface of the exposure of overlayer 12 to the thickness range of recording layer 11, Lot, from 95 μ m to 105 μ m.

With reference to figure 2, show double-deck BD200.Double-deck BD200 has the substrate of comprising 20, the first recording layers 21, the laminar structure of space layer 24, the second recording layers 23 and overlayer 22.

Typically, double-deck BD200 has the gross thickness Dt of 1200 μ m.When being set to the reference position corresponding to 22 to 23mm radial position, overlayer 22 for example has therein, and under the situation of 1.6 refractive index, overlayer 22 has the thickness of 75 μ m.Because overlayer 22 has ± thickness deviation of 5 μ m, from the surface of the exposure of overlayer 12 to the thickness of second recording layer 23, L1t, scope from 70 μ m to 80 μ m.

And, the thickness of first recording layer 21, Lot, corresponding to the thickness summation of overlayer 22, the second recording layers 23 (L1) and space layer 24, and scope from 95 μ m to 105 μ m, as among the individual layer BD.

Typically, design individual layer BD or double-deck BD200 satisfy the thickness deviation of ± 2 μ m.In order to satisfy this thickness deviation, need to realize stronger CD manufacturing accuracy.But this causes the reduction of the current given output of creating conditions down, causes the remarkable increase of CD manufacturing cost thus.On the other hand, when thickness deviation did not increase with needing, characteristics of signals worsened.In this case, in record and reproduction operating period generation error.

Summary of the invention

Therefore, consider that the problems referred to above make the present invention, and the purpose of this invention is to provide a kind of multiplayer optical disk that it can be realized making the enhancing of efficient and not cause record and the deterioration of reproducing characteristics of signals in the operation.

According to aspects of the present invention, by being provided, a kind of multiplayer optical disk realizes above-mentioned and other purpose, this multiplayer optical disk comprises: a plurality of recording layers, wherein has the tolerance of determining like this from the tectal surface of CD to the thickness of each recording layer, that is, make with from the tolerance of the relevant thickness of the farther recording layer of overlayer greater than with the tolerance of the thickness of being correlated with near tectal recording layer.

The thickness relevant with any recording layer can be corresponding to tectal thickness, or corresponding to cover thickness, than the thickness of any recording layer near the recording layer that covers, and the summation of the thickness of space layer, this space layer is than the close overlayer of any recording layer simultaneously, and is formed between two recording layers.

And have from the relevant thickness of the farther recording layer of overlayer ± tolerance of 3 μ m.And have near the relevant thickness of tectal recording layer ± tolerance of 2 μ m.Can be therein be set to the reference position, and overlayer has under the situation of 1.6 refractive index and determines thickness deviation corresponding to the radial position of the CD of 33 to 34mm radius.

According on the other hand, the invention provides multiplayer optical disk with lamination compact disk structure, comprise substrate, first recording layer, space layer, second recording layer and overlayer, wherein when overlayer has the thickness of 75 μ m, this overlayer has ± thickness deviation of 2 μ m, and at overlayer, second recording layer, when being 100 μ m with the thickness summation of space layer, it has ± tolerance of 3 μ m.

Relevant with first recording layer, can determine overlayer, the tolerance of the thickness summation of second recording layer and space layer satisfies 6.5% minimum limited balanced device (LEQ) jitter value and be not more than 10% LEQ jitter value when the radial skew of ± 0.6 degree.Relevant with second recording layer, determine that tectal thickness deviation satisfies 6.5% minimum LEQ jitter value and be not more than 10% LEQ jitter value when the radial skew of ± 0.6 degree.

Description of drawings

Comprise accompanying drawing so that further understanding of the present invention to be provided, itself and instructions show the preferred embodiments of the present invention together, to explain principle of the present invention.

Fig. 1 shows the synoptic diagram of general single-layer blue ray disc (BD);

Fig. 2 shows the synoptic diagram of general double-deck BD;

Fig. 3 shows the synoptic diagram according to double-deck BD of the present invention;

Fig. 4 shows the synoptic diagram of the process of double-deck BD constructed in accordance;

Fig. 5 shows the view according to limited balanced device (LEQ) jittering characteristic of first recording layer among the double-deck BD of the present invention; And

Fig. 6 shows the view according to limited balanced device (LEQ) jittering characteristic of second recording layer among the double-deck BD of the present invention.

Identical, equivalent or similar feature, element or the aspect according to one or more embodiment represented in feature of the present invention, element and the aspect of being represented by same numbers in the different accompanying drawings.

Embodiment

Here, with the preferred embodiment that is described in detail with reference to the attached drawings according to multiplayer optical disk of the present invention.

The present invention can be applicable to wherein polytype multiplayer optical disk of a plurality of recording layers of lamination in single substrate.

With reference to figure 3, show double-layer blue ray disc (BD) 300.Double-deck BD has the substrate of comprising 30, first recording layer 31 (L0), the compact disk structure of the lamination of space layer 34, the second recording layers 33 (L1) and overlayer 32.

Double-deck BD300 has the gross thickness Dt of 1200 μ m.The summation of the thickness of overlayer 32, second recording layer 33 and space layer 34 is corresponding to the thickness from the exposed surface of overlayer 32 to first recording layer 31, promptly, thickness L0t, it is 100 μ m, and overlayer 32 for example has therein, 1.6 the situation of refractive index under, when the radial position corresponding to 33 to 34mm radius is set to the reference position, have ± tolerance of 3 μ m.

Corresponding to thickness from the exposed surface of overlayer 32 to second recording layer 33, promptly, the thickness of the overlayer 32 of thickness L1t is 75 μ m, when the radial position corresponding to 33 to 34mm radius is set to the reference position, overlayer 32 for example has therein, has under the situation of 1.6 refractive index ± tolerance of 2 μ m.

In other words, first recording layer 31 away from overlayer 32 has ± the big relatively thickness deviation of 3 μ m more, yet has ± the relatively little thickness deviation of 2 μ m near second recording layer 33 of overlayer 32.Hereinafter, has the process of the double-deck BD of different-thickness tolerance with specifically describing the aforesaid wherein recording layer of manufacturing.

Fig. 4 shows the manufacture process according to double-deck BD of the present invention.

In the CD manufacture process, at first in injection-molded substrate 30, form pit array.

Handle on the pit array that forms in the substrate 30 according to splashing afterwards and apply reflectance coating, to form first recording layer 31 (S10).On first recording layer 31, push ultraviolet ray (UV) resin, to form space layer 34 (S11).

Afterwards, the pressing mold 40 that will have a pit array accurately is positioned at (S12) on the space layer 34.Afterwards pressure is added to pressing mold 40, causes that thus pressing mold 40 forms pit array (S13) on space layer 34.In this case, the thickness of space layer 34 remains on 20 to 30 μ m.

Next, the UV line is radiated in the substrate 30.Remove pressing mold 40 afterwards.Afterwards, on the pit array that forms on the space layer 34, apply reflectance coating according to the processing of splashing, to form second recording layer 33 (S14).

Afterwards, use the additional emulsion sheet of UV resin, and be fixed to second recording layer 33 by shining the UV resin afterwards with the UV line to second recording layer 33, and therefore, UV curing resin (S15).In this case, overlayer 32 has the thickness of about 75 μ m, and it comprises the thickness of UV resin.

In above-mentioned CD manufacture process, at first form first recording layer 31, form the space layer 34 of thickness with 20 to 30 μ m, form second recording layer 33, form overlayer 32 at last with about 75 μ m thickness.In this case, tolerance from the exposed surface of overlayer 32 to the thickness of first recording layer 31, that is, thickness L0t (100 μ m) is from the thickness deviation of space layer 34 and the thickness from the exposed surface of overlayer 32 to second recording layer 33, that is, the tolerance of thickness L1t (75 μ m) adds up.

In this respect, the tolerance of the thickness L0t relevant with first recording layer 31, for example, tolerance D0, the tolerance of the thickness L1t relevant with second recording layer 33, for example, the tolerance of the thickness of tolerance D1 and space layer 34, for example, tolerance S, have by " $\left|\mathrm{<figure-callout\; id="0"\; label="D"\; filenames="H05837979920070511E000051.png"\; state="\{\{state\}\}">D</figure-callout>}0\right|=\sqrt{{D1}^2+S^2}$ " expression relation.

With reference to this relation, the tolerance of relevant with first recording layer 31 as can be seen thickness L0t, that is, tolerance D0 is greater than the tolerance of the thickness L1t relevant with second recording layer 33, for example, tolerance D1.

Simultaneously, Fig. 5 shows when first recording layer 31 has the memory capacity of 25GB, depends on the variation of limited balanced device (LEQ) jittering characteristic of the variation of the thickness L0t relevant with first recording layer 31 (L0).When being 100 μ m with first recording layer, 31 relevant thickness L0t, and have when the tolerance of ± 3 mu m ranges, satisfying wherein minimum LEQ jitter value should be less than 6.5% condition, as shown in Figure 5.And the LEQ jitter value is not more than 10% at the radial skew of ± 0.6 degree.Therefore, guaranteed the required allowance of signal reproduction characteristic.But, with reference to figure 5, as can be seen, when thickness L0t have ± during the tolerance of 4 μ m, can not satisfy wherein minimum LEQ jitter value should be less than 6.5% condition.

Therefore, as long as have with first recording layer, 31 relevant thickness L0t ± tolerance of 3 μ m, first recording layer 31 can satisfy the desired signal characteristic.

Fig. 6 shows when second recording layer 33 (L1) has the memory capacity of 25GB, depends on the variation of limited balanced device (LEQ) jittering characteristic of the variation of the thickness L1t relevant with second recording layer 33 (L1).When being 75 μ m with second recording layer, 33 relevant thickness L1t, and have when the tolerance of ± 2 mu m ranges, satisfying wherein minimum LEQ jitter value should be less than 8.5% condition, as shown in Figure 6.And the LEQ jitter value is not more than 10% at the radial skew of ± 0.6 degree.Therefore, guaranteed the required allowance of signal reproduction characteristic.But, with reference to figure 5, as can be seen, when thickness L0t have ± during the tolerance of 3 μ m, can not satisfy wherein minimum LEQ jitter value should be less than 8.5% condition.

Therefore, as long as have with second recording layer, 33 relevant thickness L1t ± tolerance of 2 μ m, second recording layer 33 can satisfy the desired signal characteristic.

From above-mentioned explanation as can be seen, according to the present invention, can be different from the tolerance of the thickness of other recording layer by the tolerance that the thickness from tectal exposed surface to each recording layer is set in CD, and make multiplayer optical disk more effectively.Therefore, can realize the increase of CD output, and therefore, reduce the CD manufacturing cost.

Though explained the present invention by the embodiment shown in the aforesaid accompanying drawing, it should be understood by one skilled in the art that to the invention is not restricted to embodiment, but under the situation that does not break away from spirit of the present invention, can make multiple modification or change.Therefore, scope of the present invention should only be determined by appended claim and equivalent thereof.

Claims (9)

1. multiplayer optical disk comprises:

A plurality of recording layers,

Space layer is arranged between each recording layer,

Wherein, has the tolerance of determining like this from the tectal surface of CD to the thickness of each recording layer, feasible tolerance from described tectal exposure to the thickness of first recording layer is greater than the tolerance from described tectal exposure to the thickness of second recording layer, described first recording layer is that described second recording layer is more close described tectal recording layer apart from the farther recording layer of described overlayer.

2. multiplayer optical disk as claimed in claim 1, wherein, thickness from described tectal exposure to any recording layer equals described tectal thickness, or equal the summation of following thickness: described tectal thickness, than the thickness of more close described tectal at least one recording layer of this any recording layer, and than this any recording layer more close described tectal at least one be formed on the thickness of two space layer between the recording layer.

3. multiplayer optical disk as claimed in claim 1, wherein, if described multiplayer optical disk is a double-layer CD, thickness from described tectal exposure to described first recording layer has ± tolerance of 3 μ m, and the thickness from described tectal exposure to described second recording layer has ± tolerance of 2 μ m.

4. multiplayer optical disk as claimed in claim 1 wherein, is set to reference position and overlayer in the radial position corresponding to the CD of 33 to 34mm radius and has under the condition of 1.6 refractive index and determine thickness deviation.

5. multiplayer optical disk as claimed in claim 1, wherein, described multiplayer optical disk is the Blu-ray Disc with described first recording layer and described second recording layer.

6. multiplayer optical disk as claimed in claim 5, wherein, if described multiplayer optical disk is a double-layer CD, being set to reference position and overlayer in the radial position corresponding to the CD of 33 to 34mm radius has under the condition of 1.6 refractive index, thickness from described tectal exposure to described first recording layer has ± tolerance of 3 μ m, and the thickness from described tectal exposure to described second recording layer has ± tolerance of 2 μ m.

7. multiplayer optical disk, it has the compact disk structure that comprises substrate, first recording layer, space layer, second recording layer and tectal lamination,

Wherein, when this overlayer had the thickness of 75 μ m, this overlayer had ± thickness deviation of 2 μ m,

Wherein, when the thickness summation of this overlayer, second recording layer and space layer was 100 μ m, the thickness summation of this overlayer, second recording layer and space layer had ± tolerance of 3 μ m.

8. multiplayer optical disk as claimed in claim 7, wherein, determine the tolerance of the thickness summation of described overlayer, described second recording layer and described space layer, make and satisfy 6.5% minimum limited balanced device (LEQ) jitter value and when the radial skew of ± 0.6 degree, be not more than 10% LEQ jitter value.

9. multiplayer optical disk as claimed in claim 7 wherein, is determined described tectal thickness deviation, makes to satisfy 6.5% minimum efficient balance device (LEQ) jitter value and be not more than 10% LEQ jitter value when the radial skew of ± 0.6 degree.

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