HK1148104B - Optical disc and methid for fabricating the same - Google Patents

Description

Optical disc and method for manufacturing the same

Technical Field

The present invention relates to an optical disc and a method for manufacturing the same, and more particularly, to an optical disc capable of correcting deformation and a method for manufacturing the same.

Background

The optical disc can store data in various formats, is the most convenient storage medium in the new generation of optical storage market, and has a wide application range, such as library collection, data backup, electronic publishing, image data storage, personal medical record management, and the like. For the optical disk manufacturer, it is an important issue to reduce the manufacturing cost of the optical disk without affecting the read/write function of the optical disk.

PCT publication No. WO/2006/116581 discloses an optical disc (hereinafter referred to as "patent disc 1"), in which the thickness of the overlapped supporting portion and protrusion portion is larger than the thickness of the recording portion, so as to be directly clamped by the optical disc drive, and it is not necessary to add a compensation sheet to increase the thickness of the optical disc for clamping the optical disc drive, so as to reduce the manufacturing cost of the optical disc.

PCT publication No. WO/2007/056074 discloses an optical disc (hereinafter referred to as "patent disc 2") for suppressing vibration during reading and writing, which includes a damping layer to shorten the time that the optical disc is affected by vibration, thereby improving the reading and writing problems caused by the vibration of the optical disc at various speeds due to too thin thickness or insufficient rigidity.

However, in the conventional optical disc, since the thickness of the recording portion of the annular substrate is very thin (e.g. 0.55mm to 0.65mm), when the coating layer and/or the damping layer adhered to the recording portion in the optical disc manufacturing process shrinks due to the material characteristics, the recording portion of the annular substrate warps and deforms to the side where the coating layer and the damping layer are located, and even the optical disc loses the read/write function. Therefore, it is an urgent objective to improve the deformation of the conventional optical disc caused by the coating layer and/or the damping layer in the optical disc manufacturing process.

Disclosure of Invention

The present invention is to solve the problem of deformation of the conventional optical disc caused by the coating layer and/or the damping layer in the optical disc manufacturing process.

To solve the problem, the present invention provides an optical disc, which comprises: an annular substrate having an inner supporting portion and an outer recording portion, the supporting portion having a thickness greater than that of the recording portion, and the annular substrate having a recording surface corresponding to the recording portion; a coating layer formed on the recording surface for recording data; a damping layer adhered to the coating layer of the annular substrate to shorten the time of the optical disc affected by vibration; and a distortion correcting layer formed on the other surface of the annular substrate opposite to the recording surface for correcting distortion of the optical disc caused in the manufacturing process.

The present invention further provides a method for manufacturing an optical disc, comprising the steps of: manufacturing an annular substrate having an inner supporting portion and an outer recording portion, the supporting portion having a thickness greater than that of the recording portion, and the annular substrate having a recording surface corresponding to the recording portion; forming a coating layer on the recording surface for recording data; attaching a damping layer on the coating layer of the annular substrate to shorten the time of the optical disc affected by vibration; and forming a distortion correction layer on the other surface of the annular substrate opposite to the recording surface to correct distortion of the optical disc during the manufacturing process.

The invention can effectively reduce the manufacturing cost of the optical disc, effectively inhibit the vibration during the reading and writing of the optical disc, and further effectively reduce the deformation of the optical disc during the manufacturing process, improve the reading and writing characteristics of the optical disc to the same degree as that of the ordinary optical disc, and ensure that the optical disc can be read normally in the ordinary optical disc machine without any trouble.

Drawings

FIG. 1A is a schematic view showing the structure of an optical disc undergoing upward warpage deformation before an amount-of-deformation correcting layer is added.

FIG. 1B is a schematic diagram showing the improvement of warpage after adding an warpage-correcting layer to an optical disc.

FIG. 2A is a schematic view showing the structure of an optical disc with upward warp deformation in a partial area before a deformation correcting layer is added.

FIG. 2B is a schematic diagram showing the improvement of the warpage of the optical disc after the addition of the leveling layer.

FIG. 3 is a diagram illustrating the deformation of an optical disc.

FIG. 4 is a diagram illustrating a conventional optical disc.

Detailed Description

The optical disc and the method for manufacturing the same according to the present invention will be described with reference to the accompanying drawings. Wherein like elements will be referred to by like reference numerals. The vertical and horizontal directions mentioned in the description refer to vertical and horizontal directions in which the reader faces the paper.

FIG. 4 is a diagram illustrating a structure of a conventional optical disc 2. The optical disc 2 includes an annular substrate 23, a coating layer 24 and a damping layer 25. The annular substrate 23 has an inner supporting portion 21 and an outer recording portion 22, and the thickness of the supporting portion 21 is larger than that of the recording portion 22. And the annular substrate 23 also has a recording surface 231 corresponding to the recording portion 22. The coating layer 24 is formed on the recording surface 231 for recording data. The damping layer 25 is adhered to the coating layer 24 of the annular substrate 23, and since the damping layer 25 is made of a soft material, the damping coefficient of the optical disc 2 can be increased, thereby shortening the time of the optical disc 2 affected by vibration, i.e., increasing the ability of the optical disc 2 to resist change (i.e., vibration).

FIG. 3 is a diagram illustrating the deformation of an optical disc. The deformation of the optical disc can be divided into radial deformation R.D and tangential deformation T.D. As shown in FIG. 3, the radial deformation of the optical disc is + R.D. when the optical disc is bent upward, and-R.D. when the optical disc is bent downward. When the optical disc is tilted in a manner of left low and right high, the tangential deformation is + T.D., and when the optical disc is tilted in a manner of right low and left high, the tangential deformation is-T.D.. In general, the radial deformation R.D. of the optical disc (specification) capable of being read and written normally is about +0.80 to-0.80 degrees, the tangential deformation T.D. is about +0.30 to-0.30 degrees, especially the radial deformation R.D. has a great influence on whether the optical disc can be read and written normally, and when the R.D. exceeds the range of +1.00 to-1.00 degrees, the optical disc is difficult to read and write.

[ example 1]

Fig. 1A and 1B together show a structural schematic diagram of an optical disc 1 according to an embodiment of the present invention. FIG. 1A is a schematic view showing the structure of the optical disc 1 deformed by warping upward before the addition of the leveling layer 16. FIG. 1B is a schematic diagram showing the improvement of warpage after the addition of the leveling layer 16 to the optical disc 1. The optical disc 1 includes an annular substrate 13, a coating layer 14, a damping layer 15 and a deformation correcting layer 16. The annular substrate 13 has an inner supporting portion 11 and an outer recording portion 12, the thickness of the supporting portion 11 is larger than the thickness of the recording portion 12, which can be directly clamped by the optical disk drive and save the cost of additional compensation plate. The annular substrate 13 also has a recording surface 131 corresponding to the recording portion 12. The coating layer 14 is formed on the recording surface 131 for recording data. The damping layer 15 is adhered to the coating layer 14 of the annular substrate 13 to shorten the time of the optical disc 1 affected by vibration.

As shown in fig. 1A, since the thickness of the recording portion 12 of the annular substrate 13 is very thin (e.g., 0.55mm to 0.65mm), when the coating layer 14 and the damping layer 15 adhered to the recording portion 12 shrink due to material characteristics in the optical disc manufacturing process, the recording portion 12 of the annular substrate 13 is warped and deformed toward the coating layer 14 and the damping layer 15, where the deformation is set to be + r.d.

As shown in FIG. 1B, the optical disc 1 is added with the deformation correcting layer 16, the deformation correcting layer 16 is formed on the other surface 132 of the annular substrate 13 opposite to the recording surface 131, and when the deformation correcting layer 16 shrinks due to the material characteristics, the whole or a part of the disc deformation + R.D. caused by the coating layer 14 and/or the damping layer 15 in the optical disc manufacturing process can be corrected (offset). The deformation of the corrected compact disk is + R'.

[ example 2]

Fig. 2A and 2B together show a schematic structural diagram of an optical disc 1 according to another embodiment of the present invention. FIG. 2A is a schematic view showing the structure of the optical disc 1 with a portion of the area warped upward before the addition of the leveling layer 16. FIG. 2B is a schematic diagram illustrating the improvement of the warpage of the optical disc 1 after the addition of the leveling layer 16.

As shown in fig. 2A, only one side (portion) of the recording portion 12 of the annular substrate 13 is warped and deformed toward the coating layer 14 and the damping layer 15. The deformation amount is set to + r.d.

As shown in FIG. 2B, the optical disc 1 is added with the deformation correcting layer 16, the deformation correcting layer 16 is formed on a side (partial) area of the other surface 132 of the annular substrate 13 opposite to the recording surface 131, and corrects the disc deformation + R.D. caused by the coating layer 14 and/or the damping layer 15 in the optical disc manufacturing process to + R'. Wherein + R.D. is greater than + R'. D.

In the above embodiment, the deformation of the optical disc that can be corrected (offset) by the deformation correcting layer 16, i.e., the effect of the deformation correcting layer 16 on the optical disc, is influenced by the material characteristics, the position of the film formation, the range of the film formation, and the thickness of the film layer, and the like, so that the skilled person can properly adjust the material, position, range, thickness, and the like of the film formation of the deformation correcting layer 16 to achieve the desired effect of correcting the deformation by considering the size of the range of the deformation region of the optical disc and the amount of deformation of the optical disc.

[ Table 1]

Table 1 shows experimental data on the effect of correcting the deformation of the layer of the optical disc of the present invention. The experiment selects 5 existing discs such as a general optical disc, b patent disc 1, c patent disc 1+ deformation correction layer, d patent disc 2, e patent disc 2+ deformation correction layer, etc., measures the maximum value and the minimum value of radial deformation R.D. and tangential deformation T.D. of each disc, and records the average value Max of the maximum value and the average value Min of the minimum value of 5 discs of the same type. The closer the maximum value and the minimum value are to zero, the smaller the deformation amount is, the flatter the optical disc is, and the better the read-write characteristics are.

As can be seen from the data of items a, b, and c in the table, the average value max and the average value min of each t.d. are within the normal readable and writable optical disc specification range (plus or minus 0.3 degrees). The average value Max of R.D. of general optical disk is 0.14 degree, and the average value Min is-0.20 degree, and is in the specification range (plus or minus 0.8 degree) of general optical disk capable of normal reading and writing. After the disc 1 is provided with the deformation correcting layer, the average value Max of R.D. is improved from 0.95 degree to 0.19 degree, and the average value Min is slightly changed from 0.04 degree to-0.34 degree, which reaches the deformation about the same as that of the general disc, and is within the specification range (plus or minus 0.8 degree) of the general disc capable of normal reading and writing. It can be seen that the layer for correcting distortion can effectively reduce the r.d. of the patent disc 1. The actual testing of the optical disc of item c also shows that it can be read/written normally in a normal optical disc drive.

As can be seen from the data of the items d and e in the table, the average value max and the average value min of each t.d. are within the normal readable and writable specification range (plus or minus 0.3 degrees). After the deformation correction layer is added to the patent disc 2, the average max of r.d. is improved from the original 2.37 degrees to 1.83 degrees, and the average min is also slightly reduced from the original 0.53 degrees to 0.26 degrees, although the deformation is not about the same as that of the general optical disc and is outside the specification range (plus or minus 0.8 degrees) of the normal readable and writable optical disc, the deformation correction layer can effectively reduce the radial deformation r.d. of the patent disc 2, and the normal readable and writable optical disc can be found after the actual test of the optical disc of item e.

The reason why the r.d. of the patent disc 2 exceeds the specification range of the normal readable and writable optical disc is that the structure of the patent disc 1 and the patent disc 2 is different from the normal optical disc, and after further tests by the applicant, the r.d. of the invention is biased to a positive value and becomes smaller due to centrifugal force during high-speed rotation (the static r.d. is larger than the dynamic R.D). in practice, even if the static r.d. is close to +3.0 degrees, normal reading and writing can still be performed, but the reading and writing characteristics are poor, so that the r.d. value still needs to be reduced.

In addition, the deformation correcting layer of the optical disc of the present invention can be formed by any material, and is not particularly limited. However, from the viewpoint of scratch resistance, antistatic adsorption, prevention of deformation or electrostatic aggregation due to moisture or temperature, prevention of adhesion of oil and water, or fingerprint, a material for a film layer such as an ultraviolet ray curable resin film, a silica film, a diamond-like carbon film, a magnesium fluoride film, or a fluorine plating film is preferable. Among them, the UV curable resin film is preferably selected from the viewpoint of facilitating the correction amount required for the adjustment by changing the components to be mixed. The deformation correcting layer may be formed by any film forming method such as printing, coating, sputtering, vacuum deposition, or chemical deposition, as appropriate, depending on the material, and is not particularly limited. The thickness of the strain-correcting layer is preferably 1 μm to 600. mu.m.

The technical features of the present invention have been specifically described above with reference to the preferred embodiments of the present invention, but the present invention is only by way of illustration and not limitation; in other words, those skilled in the art can make various modifications and changes to the present invention without departing from the true spirit and novel teachings of the present invention, and such modifications and changes are intended to be covered by the scope of the appended claims.

Industrial applicability

The present invention discloses an optical disc, which comprises: an annular substrate having a supporting portion and a recording portion, a coating layer, a damping layer, and a distortion correcting layer. The thickness of the supporting part is larger than that of the recording part, so as to be directly clamped by the CD-ROM, thereby reducing the cost of manufacturing the CD-ROM. The deformation correcting layer can minimize the warpage of the optical disc caused by the coating layer and the damping layer during the manufacturing process, so that the optical disc can maintain good read/write characteristics.

Claims (8)

1. An optical disc, comprising:

an annular substrate having an inner supporting portion and an outer recording portion, the supporting portion having a thickness greater than that of the recording portion, and the annular substrate having a recording surface corresponding to the recording portion;

a coating layer formed on the recording surface for recording data;

a damping layer adhered to the coating layer of the annular substrate to shorten the time of the optical disc affected by vibration; and

a deformation amount correcting layer formed on the other surface of the annular substrate opposite to the recording surface and correcting deformation amount of the optical disc caused by the coating layer and/or the damping layer in the manufacturing process by using the shrinkage of the deformation amount correcting layer,

wherein the thickness of the deformation correcting layer is between 1 μm and 600 μm.

2. The optical disc according to claim 1, wherein,

the deformation correcting layer is formed on a partial region of the other surface.

3. The optical disc of claim 1 or 2,

the distortion correcting layer is composed of an ultraviolet curable resin film, a silica film, a diamond-like carbon film, a magnesium difluoride film or a fluorine plating film.

4. The optical disc of claim 1 or 2,

the deformation correcting layer is formed by printing, coating, sputtering, vacuum evaporation or chemical evaporation.

5. A method for manufacturing an optical disc includes the steps of:

manufacturing an annular substrate having an inner supporting portion and an outer recording portion, the supporting portion having a thickness greater than that of the recording portion, and the annular substrate having a recording surface corresponding to the recording portion;

forming a coating layer on the recording surface for recording data;

attaching a damping layer on the coating layer of the annular substrate to shorten the time of the optical disc affected by vibration; and

forming a distortion correction layer on the other surface of the annular substrate opposite to the recording surface, and correcting the distortion of the optical disc caused by the coating layer and/or the damping layer during the manufacturing process by using the shrinkage of the distortion correction layer,

wherein the thickness of the deformation correcting layer is between 1 μm and 600 μm.

6. The method of manufacturing an optical disc according to claim 5,

the deformation correcting layer is formed on a partial region of the other surface.

7. The method of manufacturing an optical disc according to claim 5 or 6,

the distortion correcting layer is composed of an ultraviolet curable resin film, a silica film, a diamond-like carbon film, a magnesium difluoride film or a fluorine plating film.

8. The method of manufacturing an optical disc according to claim 5 or 6,

the deformation correcting layer is formed by printing, coating, sputtering, vacuum evaporation or chemical evaporation.