KR0186205B1 - Information recording / reproducing method of optical disk and the disk manufacturing method - Google Patents

Abstract

The present invention relates to an information recording / reproducing and manufacturing method of an optical disc. In particular, in the reproduction of an optical disc recorded by using a polarization method, an optical disc having a double density is controlled by controlling a polarization direction with only one laser diode. A double-density optical disc reproduction method for reproduction.

Even if the recording density is maximized by the semiconductor laser wavelength, enough information is not stored in one sheet, and therefore, additional efforts such as overlapping two disks or two grooved surfaces are required. .

In particular, when recording movies, the recording density is severely restricted. Even if the size of a conventional CD-level disc is increased by DVD (Digital Video Disk) technology, it is difficult to record one movie on one disc. There is a need for improvement such as overlapping, and thus, the manufacturing process becomes more complicated and additional systems also require many modifications.

According to an aspect of the present invention, there is provided a method of manufacturing an information recording method of an optical disk, comprising: first coating a polarizing material of a liquid crystal polymer having polarization characteristics on an optical disk; A second step of recording information on the surface of the optical disc coated with the polarizing material by using a photomask, dividing a spot of information recorded on the optical disc into two compartments and recording the information with ultraviolet light polarized to have a direction directed toward the center; And a third step of recording the information with the ultraviolet rays polarized so that the remaining second compartment has a direction orthogonal to the first compartment.

Further, the method of reproducing the information recording of the optical disc according to the present invention for achieving the above object is divided into two divisions in the polarization direction by the smallest division defined by the seeding of the light, and recorded twice in the central direction and in the polarization direction perpendicular to each other. A density optical disc, comprising: a first step of reading recorded information by irradiating light polarized in a center direction to read information polarized in the center direction; A second step of changing the light polarized toward the center at a right angle; The information recording / reproducing and manufacturing method of the optical disc according to the present invention comprises a third step of reading polarized information in a direction orthogonal to the center direction. The mask operation is used to record and reproduce information on the optical disc at high density.

In addition, in the wavelength of light used in the conventional CD, the maximum recording density limited by the wavelength of light can be used to store two pieces of information within the minimum wavelength of light using the polarization characteristic of the light, thereby doubling the recording density. It has an effect.

Description

Information recording / playback and manufacturing method of optical disc

1 is a diagram showing a procedure of an information recording / reproducing and manufacturing method of an optical disc according to the present invention.

2 is a diagram showing a double density information recording method of an optical disc according to the present invention.

3 is a diagram showing a method for reproducing twice the density information of an optical disc according to the present invention.

The present invention relates to an information recording / reproducing and manufacturing method of an optical disc. In particular, in the recording and reproduction of an optical disc using a polarization method, a high-density optical disc is reproduced by controlling a polarization direction with only one laser diode. An information recording / reproducing and manufacturing method of an optical disc.

In general, the optical disc recording method according to the prior art is divided into two types that can be used only for reproduction and recording and reproduction.

First of all, the recording and reproducing method can be used by coating a magnetic thin film or phase change material on the surface of the disc to induce their characteristic change by laser light, and outputting the changed characteristic again. The method of reading with this low laser light is taken.

In addition, the reproduction-only method is the most commonly used method because it is cheap and easy to mass-produce, which is used as an optical sensor because it does not reflect light by concave the signal part on the surface of the disc. Read and reduce to digital signal.

In the above manufacturing method, first, the desired information is inputted into the original plate to convexly protrude the part with the signal, and then it is thermally press-bonded with the plate used for the CD. Let it go.

The metal plate is coated on the CD plate so that the light can be reflected and used as an optical recording and reproducing apparatus.

Currently, the reproduction-only method using the above-described method is applied to a DVD (Digital Video Disk), and technical progress has been made to have a density 10 times higher than that used in a conventional CD.

At this time, in the reproduction-only method used in the conventional CD, as the recording density increases, the information transplantation method by thermal compression between the original plate and the CD plate may cause a recording error during mass production, and the recording size should be within 1 μm mechanically. It is difficult to drill precisely and it is not easy for these small holes to be drilled evenly across the board.

In particular, the present invention uses a red laser light, but when a semiconductor laser device capable of emitting a blue laser light is developed in the future, the size of the hole should be smaller, which makes it more difficult to mechanically dig a groove. .

In addition, even if the recording density is maximized by the semiconductor laser wavelength, a sufficient amount of information cannot be stored in a single plate, so additional efforts such as overlapping two disks or two grooved surfaces are required. Done.

In particular, when recording movies, the recording density is restricted. Even though the size of a conventional CD-level disc is increased by DVD (Digital Video Disk) technology, it is difficult to record one movie on one disc. There is a need for improvement such as overlapping, and thus, the manufacturing process becomes more complicated and additional systems also require many modifications.

Therefore, the optical disc information recording / reproducing and manufacturing method according to the present invention is devised to solve the above-mentioned problems of the prior art, and an object of the present invention is to use the characteristics of the laser light that is polarized and emitted to the surface of the optical disc. It is possible to reproduce information by recording information by polarizing material. In particular, one spot divided by the wavelength of light can be divided into two sections so that information can be recorded in the polarization direction orthogonal to each other. The present invention provides an optical disc information recording and reproducing method for reproducing an optical disc of high density by making it compatible with a CD device.

According to an aspect of the present invention, there is provided a method of manufacturing an information recording method of an optical disk, comprising: first coating a polarizing material of a liquid crystal polymer having polarization characteristics on an optical disk; A second step of recording information on the surface of the optical disc coated with the polarizing material by using a photomask, dividing a spot of information recorded on the optical disc into two compartments and recording the information with ultraviolet light polarized to have a direction directed toward the center; And a third step of recording the information with the ultraviolet rays polarized so that the remaining second compartment has a direction orthogonal to the first compartment.

Further, the method of reproducing the information recording of the optical disc according to the present invention for achieving the above object divides the minimum section defined by the seeding of the light into two compartments in the polarization direction, respectively, recorded twice in the center direction and in the polarization direction orthogonal thereto. A density optical disc, comprising: a first step of reading recorded information by irradiating light polarized in a center direction to read information polarized in the center direction; A second step of changing the light polarized toward the center at a right angle; And a third step of reading information polarized in a direction orthogonal to the center direction.

Hereinafter, an information recording / reproducing and manufacturing method of an optical disc according to the technique of the present invention will be described with reference to the accompanying drawings.

1 is a view showing a procedure of information recording / reproducing and manufacturing method of an optical disc according to the present invention, FIG. 2 is a view showing a double density information recording method of an optical disc according to the present invention, and FIG. Fig. 2 shows a method of reproducing twice the density information of an optical disc.

As shown in FIG. 1 (a), the optical disc information recording method of the present invention first spin-coats a polarizing material of liquid crystal polymer having polarization characteristics on the surface of the optical disc in the first step (101), and in the second step, laser light. Only the top half of the minimum spot for By polarized ultraviolet light and information recorded photomask The polarized information is recorded (102S).

In the third step, only the lower half of the minimum spot is applied to the laser beam. By polarized light ultraviolet light and photomask on which information is recorded By recording the polarized information (103), an optical disk having a double density is produced (104).

In addition, when reproducing the recorded information, first, as shown in FIG. Direction is polarized (105S), and in the second step, Read all the information polarized in the direction (106S), and in the third step again the laser light by the polarization crystal That is, the polarization is orthogonal to the polarization direction of the fourth step (107S).

In the fourth step, the two compartments of the optical disc All the information polarized in the direction is read and the recorded information is reproduced (108S).

Here, the polarization directions of the two sections of the spot are recorded and reproduced with polarization perpendicular to each other.

Therefore, the information is reproduced by recording the information on the surface of the optical disc by using a polarizing material by using the characteristics of the polarized and divergent laser light. As shown in FIG. 2, one spot is divided into two sections. In an optical disc capable of recording information in the orthogonal polarization direction, as shown in FIG. 2, only one laser diode can be used to reproduce it, which is advantageous to make it compatible with a conventional CD.

The structure and the embodiment of the ultraviolet polarizing material are as follows.

In the structural formula of the ultraviolet polarizing material m is 4 to 12, n is 1 to 3.

The inherent viscosity of the synthesized poly (malonic acid ester) has a value between about 0.05-1.0.

However, for use as an information recording medium, it is more advantageous that the number of methylene groups in the main chain is m = 6 and that the low molecular weight has an intrinsic viscosity between 0.05 and 0.4.

A method of storing information in an optical disc by polarization is as follows.

First, a thin polarizing material of a solution of a liquid crystal polymer having the above structural formula having optical polarization characteristics on a clean optical disk is applied by spin coating.

After the drying process in this state is heated to more than the melting temperature inherent to the liquid crystal polymer used, and then quenched to room temperature to obtain a film fixed in an isotropic state.

A photo mask containing a fine pattern is placed thereon and irradiated with ultraviolet rays having a maximum absorption wavelength of 365 nm in a polarized state through an optical filter and a polarizing plate, and then cooled to room temperature to store information.

In the above process, the polarized ultraviolet light is irradiated with the liquid crystal polymer having the unidirectionality in the same direction as the polarized direction of the ultraviolet light, and this state acts like a polarizing plate.

That is, it absorbs light polarized in the same direction as the liquid crystalline polymer having unidirectionality.

In addition, the part which is not irradiated with polarized ultraviolet rays absorbs any light.

In summary, the information storage principle described above is a part irradiated with light when an isotropic state obtained by heating to a temperature higher than the intrinsic melting temperature of a liquid crystal polymer thin film spin-coated on a disk and then quenching to room temperature is exposed to ultraviolet polarized light that has passed through a photomask. The photoisomerization reaction of the azobenzene is used to completely pass light polarized in the same direction by being phase-translated and fixed in an isotropic state to a uniformly oriented liquid crystal phase.

Here, the metal reflective film is coated on the coated film again.

The information recording / reproducing and manufacturing method of the optical disc according to the present invention will be described in more detail as follows.

One spot determined by the wavelength of light is divided into two compartments, one of which has a direction directed toward the center, and one of which is designated as a direction having a direction in the direction orthogonal thereto.

The first section, which is oriented towards the center, emits ultraviolet light polarized in this direction when light is to be reflected when storing information, so that the liquid crystal polymer is unidirectional in the same direction. So that it is isotropic.

Therefore, if the polarization direction of the laser diode is the same as the original ultraviolet ray and the polarized light is used, the portion where the ultraviolet rays are reflected is the light on which the light is reflected, and the portion that is not the ultraviolet rays is reflected the light. If not, it becomes an Off signal.

Section 2, which makes it directional in the direction perpendicular to the centerline, produces a signal where the signal should be irradiated with UV light polarized in this direction and the area where no signal should be irradiated.

When reading this, a laser diode polarized in the same direction as polarized ultraviolet rays as shown in section 1 can be used to read the signal as being reflected and not reflected.

In other words, the polarization direction of the laser diode is fixed toward the center of the disk, and the information of the first partition is read first and the information is stored in the partitions 1 and 2 of the disk, which store information with light polarized toward the center of the disk. After reading, the polarization converting part is located in front of the laser diode so that the polarization direction of the laser light is orthogonal to the center line of the disk, so that section 2 stored as light polarized in this direction is read to reproduce the recorded information.

Therefore, when reading Section 1, use the polarized light as the centerline, so that Section 2 always absorbs the light and does not interfere with the signal from Section 1, and when reading Section 2 uses the light polarized in the direction orthogonal to the center line, Absorbs the enhancement light and has no effect on the signal in compartment 2.

As described above, the information recording / reproducing and manufacturing method of the optical disc according to the present invention enables the recording and reproducing of the optical disc with high density using a photomask operation in the same manner as the semiconductor manufacturing process as the wavelength of the laser becomes shorter. .

In addition, in the wavelength of light used in the conventional CD, the maximum recording density limited by the wavelength of light can be used to store two pieces of information within the minimum wavelength of light using the polarization characteristic of the light, thereby increasing the recording density. There is.

Claims (4)

Coating a polarizing material of a liquid crystal polymer having polarization characteristics on the optical disk; A second step of recording information on the surface of the optical disc coated with the polarizing material by using a photomask, dividing a spot of information recorded on the optical disc into two compartments and recording the information with ultraviolet light polarized to have a direction directed toward the center; And a third step of recording the information with the ultraviolet rays polarized so that the remaining second compartment has a direction orthogonal to the first compartment. The information recording manufacturing method of an optical disc according to claim 1, wherein said second step is shielded with a photomask during manufacturing. The information recording manufacturing method of an optical disc according to claim 1, wherein in the third step, the first compartment during manufacturing is shielded with a photomask. A double-density optical disc recorded by dividing the minimum section defined by the seeding of light into two compartments in the polarization direction, respectively, in a central direction and a polarization direction orthogonal thereto, wherein the optically polarized in the central direction is used to read the information polarized in the central direction. A first step of reading the recorded information by irradiating light; A second step of changing the light polarized toward the center at a right angle; And a third step of reading information polarized in a direction orthogonal to the center direction.