CN1352456A - Multilayer multi stage CD with multilayer rewritable phase change recording layers - Google Patents

Abstract

The multi-layer multi-level optical disc with multi-layer rewritable phase-change recording layer belongs to the technical field of optical data storage, and is characterized in that the disc has a transparent substrate through which laser light is incident. The substrate supports at least two spatially separated but adjacent multilayer recording stacks, and may support only one multilayer recording stack. Each stack includes an active recording layer of rewritable phase change material. All recording stacks are located within the focal depth range of the objective lens of the optical disc system, and data can be recorded on different recording stacks and combinations of recording stacks by adjusting the power of the laser to achieve multi-layer and multi-level storage. It has the advantages of simple hierarchical structure, easy access and reading, and simple manufacturing process.

Description

Multi-layer multi-level optical disc with multi-layer rewritable phase-change recording layer

technical field

A multi-layer multi-level optical disc with multi-layer rewritable phase-change recording layers belongs to the technical field of optical discs for optical data storage.

Background technique

Generally, optical discs can be classified into read-only optical discs, write-once optical discs and rewritable optical discs. In rewritable optical discs that use phase change media as the recording medium layer, it is usually a single layer. International Business Machines Corporation proposed an "optical data storage system with multiple rewritable phase-change recording layers" in Chinese patent application No. 97111146.4. The disc structure is characterized by: supporting at least Two multi-layer recording stacks spaced apart from each other, the stack spacing is between 10 and 300 microns, and the laser can be focused on different recording stacks by adjusting the position of the objective lens in the storage system to realize multi-layer storage. Its disadvantages are: the laser focus position is achieved by adjusting the position of the objective lens, so the focusing device and algorithm of the storage system using this disc are more complicated than the conventional optical disc system; secondly, its layered structure is complicated, and the process and equipment are also corresponding complex.

Contents of the invention

The object of the present invention is to provide a multi-layer multi-level optical disc with multi-layer rewritable phase-change recording layers, which has simple layered structure, easy access and reading, and simple manufacturing process.

The present invention is characterized in that it contains the following layers that are closely stacked in sequence: a substrate whose first surface is the outer surface of the optical disc, with a thickness of 0.1 mm to 10 mm; n (2≤n≤10) recording stacks, each A recording stack includes a recording medium layer made of a rewritable phase-change material and a spacer layer, the total thickness of all recording stacks is less than the focal depth of the optical disc system objective lens; the reflective layer has a thickness of 5nm to 1000nm; the protective layer, The thickness is 1 μm to 5 mm.

The present invention is also characterized in that it contains:

(1) Two recording surfaces, each of which contains the following layers stacked one after the other: a substrate whose first surface is the outer surface of the optical disc; n (2≤n≤10) recording stacks, each The recording stack includes a recording medium layer composed of a rewritable phase-change material and a spacer layer, the total thickness of all recording stacks does not exceed the focal depth of the optical disc system objective lens; a reflective layer and a protective layer;

(2) An adhesive layer, the two sides of which are respectively bonded to the protective layers of the two recording surfaces to form a double-sided optical disc.

The rewritable phase change material of the recording medium layer in each recording stack is an alloy with the composition of G _x Te _y Sb _z , wherein 10<x<15, 45<y<55, 38<z<48, x +y+z=100%.

The spacer layer is SiO _x (1<x<2.1).

The material of the spacer layer in each recording medium layer is a mixture of ZnS and SiO ₂ .

Proof of use: It served its intended purpose.

Description of drawings

Figure 1. Schematic cross-sectional view of a single-sided multilayer multilevel optical disc with multiple rewritable phase-change recording layers.

Figure 2. Schematic cross-sectional view of a double-sided multilayer multilevel optical disc with multiple rewritable phase-change recording layers.

Figure 3. Schematic view of a cross-section of a single recording stack.

Figure 4. Schematic view of a cross-section of n recording stacks.

Figure 5. One of the embodiments of the present invention: a cross-sectional view of a single-sided multi-layer multi-level optical disc with multi-layer rewritable phase-change recording layers with 3 recording stacks.

Figure 6. Embodiment 2 of the present invention: a cross-sectional view of a double-sided multi-layer multi-level optical disc with multiple rewritable phase-change recording layers having 3 recording stacks.

Detailed ways

Please see Figure 1. 1 is an optical disc, 3 is a substrate, and its first surface is the outer surface 2 of the disc. The laser light is incident from this surface. The substrate 3 is made of light-transmitting material glass, polycarbonate or other polymer materials can also be used. There are n (2≤n≤10) recording stacks 4 on the substrate 3, wherein each recording stack has a recording medium layer and a spacer layer. The total thickness of the n recording stacks does not exceed the focal depth of the system objective lens, generally around 1 μm. There is a reflective layer on the recording stack 4, and the material of the reflective layer is metal with high reflectivity, such as Al, Au and Ag. On the reflective layer 5 there is a protective layer 6 . Please see Figure 2. The optical disc 7 has two sides, and the structures of the two sides are symmetrical. The surfaces 2 and 9 are the first surface and the second surface of the optical disc 7 respectively, and laser light can be incident on any one of the surfaces to write, read and erase the corresponding recording medium. On the substrate 3 is an n-layer recording stack 4 and on the recording stack 4 a reflective layer 5 and a protective layer 6 . On another substrate 3 are m recording stacks 10, where m and n may be equal or different. On the recording stack 10 is a reflective layer 5 and a protective layer 6 . The adhesive layer 8 bonds the two parts together in a "back-to-back" manner to form a double-sided disc. In FIG. 3, 11 is a single recording stack, 12 is a recording medium layer, and 13 is a spacer layer.

In Fig. 4, among the n recording stacks 4, 14, 15, and 16 are the first, second, and third recording stacks respectively, 17 is the m recording stacks, and 18 is the n~1 recording stacks. Stack, 19 is the nth recording stack.

Fig. 5 is Embodiment 1 of the present invention. In the optical disc 1, three recording laminations 20-22 are sequentially coated on the substrate 3 by vacuum sputtering coating equipment. Each recording stack comprises a recording medium layer 12 and a spacer layer 13 . Plating reflective layer 5 again, spin coating protective layer 6. Wherein, the material of the substrate 3 is polycarbonate, and the thickness is 1.2 mm. For the recording stacks 20-22, the material of each recording medium layer 12 is Ge ₂₁ Te ₅₃ Sb ₂₆ , and the material of each spacer layer 13 is ZnS-SiO ₂ . The thickness of the recording medium layer 12 of the recording stack 20 is 8nm, and the thickness of the spacer layer 13 is 40nm; the thickness of the recording medium layer 12 of the recording stack 21 is 8nm, and the thickness of the spacer layer 13 is 12nm; the recording of the recording stack 22 The thickness of the dielectric layer 12 is 7 nm, and the thickness of the spacer layer 13 is 50 nm. The reflective layer 5 is made of Al and has a thickness of 40nm. The protective layer 6 is made of UV glue with a thickness of 20 μm.

Fig. 6 is Embodiment 2 of the present invention. In the optical disc 7, the two parts are bonded together by the adhesive layer 8 to form a double-sided disc, and the adhesive is UV glue. Both the upper and lower substrates 3 have a thickness of 0.6 mm and are made of polycarbonate. In each recording stack, the material of the recording medium layer 12 is Ge ₂₁ Te ₅₃ Sb ₂₆ , and the material of each spacer layer 13 is ZnS-SiO ₂ . The thickness of the recording medium layer 12 of the recording stack 23 is 8nm, and the thickness of the spacer layer 13 is 40nm; the thickness of the recording medium layer 12 of the recording stack 24 is 8nm, and the thickness of the spacer layer 13 is 12nm; the recording of the recording stack 25 The thickness of the medium 12 is 7 nm, and the thickness of the spacer layer 13 is 50 nm. The reflective layer 5 is made of Al and has a thickness of 40nm. The protective layer 6 is made of UV glue with a thickness of 20 μm. The material of the adhesive layer 8 is UV glue with a thickness of 100 μm.

It can be seen that its layered structure is simple, easy to access and read, and the manufacturing process is simple.

Claims (5)

1. multi-layer multi-stage optical disk with multi-layer rewriting phase-change record layer, contain substrate, recording stack, reflection horizon and protective seam, it is characterized in that it contains closely folded mutually successively following each layer: first surface is the substrate of CD outside surface, and thickness is 0.1mm～10mm; The individual recording stack of n (2≤n≤10), each recording stack comprise recording dielectric layer and wall that a rewritable phase change material is made, and the gross thickness of all recording stacks is less than the depth of focus of optical disk system object lens; Reflection horizon, thickness are 5nm～1000nm; Protective seam, thickness are 1 μ m～5mm.

2. the multi-layer multi-stage optical disk with multi-layer rewriting phase-change record layer contains substrate, recording stack, reflection horizon and protective seam, it is characterized in that it contains:

(1) two record surface, each record surface contain successively near stacked following each layer: its first surface is the substrate of CD outside surface; The individual recording stack of n (2≤n≤10), each recording stack comprise a recording dielectric layer and the wall be made up of the rewritable phase change material, and the gross thickness of all recording stacks is no more than the depth of focus of optical disk system object lens; Reflection horizon and protective seam;

(2) adhesive linkages, its two sides is bonding with the protective seam of two record surfaces respectively, forms a both-sided optical disc.

3. according to any one the multi-layer multi-stage optical disk with multi-layer rewriting phase-change record layer in claim 1 or 2, it is characterized in that: the rewritable phase change material of recording dielectric layer is that composition is Ge in described each recording stack _xTe _ySb _zAlloy, wherein, 10＜x＜15,45＜y＜55,38＜z＜48, x+y+z=100%.

4. according to any one the multi-layer multi-stage optical disk with multi-layer rewriting phase-change record layer in claim 1 or 2, it is characterized in that: described wall is SiO _x(1＜x＜2.1).

5. according to any one the multi-layer multi-stage optical disk with multi-layer rewriting phase-change record layer in claim 1 or 2, it is characterized in that: described each recording dielectric layer intermediate interlayer material is ZnS and SiO ₂Potpourri.

Images