KR100817717B1 - Optical information processing apparatus, method of recording optical information and method of reading optical information - Google Patents

Abstract

The present invention relates to an optical information recording and reproducing and a device therefor, wherein the reference light and the signal light are moved through a coaxial optical system to enable recording and reproducing of a large amount of holographic optical information, and an optical modulator for multiple recording and reproduction of optical information. By varying the pattern of the reference light provided from to other reference light patterns that are not correlated with each other and providing it as the reference light, the optical information multiplexing is more effectively performed in the optical information processing apparatus using the coaxial optical system. There is an effect to improve the use efficiency.

Description

Optical information processing apparatus, optical information recording method and optical information reproducing method using the same {Optical information processing apparatus, method of recording optical information and method of reading optical information}

1 is a block diagram showing an optical information processing apparatus according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating a progress state of a signal light and a reference light at the time of recording optical information in the optical information processing apparatus according to the embodiment of the present invention.

3 is a view showing a signal light pattern and a reference light pattern at the time of recording optical information in the optical information processing apparatus according to the embodiment of the present invention.

4A and 4B are enlarged views of a reference light pattern in an optical modulator when multiplexing optical information according to an exemplary embodiment of the present invention.

5 is a graph showing diffraction efficiency with respect to the pattern rotation angle of the symbol light according to an embodiment of the present invention.

6 is a graph showing a noise rate with respect to the pattern rotation angle of the reference light according to an embodiment of the present invention.

7 is a graph showing the relationship between the thickness of the optical information storage medium and the diffraction efficiency.

8A is a photograph showing a reproduction result of optical information when the rotation angle of the reference light pattern is "0 degree" as an experimental example according to an embodiment of the present invention.

8B to 8E illustrate experimental results of optical information when the rotation angles of the reference light patterns are “2 degrees”, “4 degrees”, “6 degrees”, and “8 degrees”, respectively. It is a photograph showing.

9A and 9B illustrate reference light patterns in an optical modulator when multiplexing optical information according to another embodiment of the present invention.

10A and 10B illustrate a pattern of reference light according to another exemplary embodiment of the present invention.

11 is a block diagram showing an optical information processing apparatus according to another embodiment of the present invention.

12 is a flowchart showing an optical information recording method according to an embodiment of the present invention.

13 is a flowchart illustrating a method of reproducing optical information according to an embodiment of the present invention.

The present invention relates to an optical information processing apparatus, an optical information recording method, and an optical information reproducing method, and more particularly, optical information processing in which multiplexing is performed by modifying a reference light pattern formed on an optical modulator during multiple recording of optical information. A device, an optical information recording method, and an optical information reproducing method.

Optical data processing apparatuses include Digital Versatile Disc (DVD), HD-DVD, Blu-ray Disc (BD), near field light processing apparatus, holographic light processing apparatus, and the like.

The holographic optical information processing apparatus receives an optical modulated signal beam and a reference beam that intersects the signal beam to form an interference fringe on the storage medium, and stores the data by entering the storage medium. . In the reproduction of data, only the reference light is incident on the interference fringe of the storage medium so that data input to the storage medium is output by diffraction generated from the interference fringe.

In order to increase the recording capacity, the holographic optical information processing apparatus may store data in a multiplex by irradiating a reference light to one beam spot at different angles. The multi-input data can be output by irradiating only the reference light at different angles during reproduction. In other words, the holographic light processing device is a supercapacitive data storage device capable of inputting and outputting data in a multi-layered and overlapping state at one light spot.

In the holographic optical information processing apparatus, a method of multiplexing light is used to increase the recording density of data. Methods of multiplexing light include angular multiplexing, phase-code multiplexing, wavelength multiplexing, shift multiplexing, and the like. Here, the angle multiplexing method is to multiplex by changing the incident angle of the reference light, the phase code multiplexing is to multiplex by spatially modulating the phase, the wavelength multiplexing is to multiplex according to the wavelength change using a wavelength tunable laser, shift multiplexing There is a method of multiplexing records while moving the storage medium.

As mentioned above, the holographic optical information storage device irradiates the reference light and the signal light to the storage medium at different angles, and when regenerating the light, the reference light is incident on the storage medium and diffracted from the storage medium to the opposite side to the optical information detector. Detect and play back data. Prior arts for such a technique are disclosed in US Patent No. 6058232, "Volume holographic data storage system using a beam pattern from a tapered optical fiber," such as "Byeong Ho Lee".

In addition, recently disclosed US Patent Application Publication No. 2005-0007930, "Optical information recording apparatus" filed by "Hideyoshi" and the like. The U.S. Patent Publication discloses a technique of using a digital micromirror device (DMD) as a spatial light modulator and injecting reference light and signal light into a storage medium when recording optical information in an optical path having the same optical axis.

On the other hand, as mentioned earlier, the holographic optical information processing apparatus mentioned that multiplexing of optical information is possible. However, in the case of US Patent Publication '7930', since the reference light and the signal light have the same optical axis, the multiplexing method of optical information is not easy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to record and reproduce optical information using a reference light and a signal light with a coaxial optical system, and to adjust a reference light pattern of a light changer that reflects the reference light to multi-process the optical information. It is to provide an optical information processing apparatus, a recording apparatus and a reproducing apparatus, and an optical information recording method and an optical information reproducing method using the same.

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An optical information recording apparatus according to the present invention comprises: a light source for providing light; Forming a reference light pattern and a signal light pattern for modulating the light into a reference light and a signal light, and the reference light pattern is modulated in another area where the reference light is not overlapped with each other when optical information is recorded in a recording area of an optical information storage medium. Varying light modulators; And a lens configured to interfere with the reference light and the signal light traveling from the optical modulator in the optical information storage medium to store the optical information.
The reference light and the signal light are incident together with the lens in the coaxial direction, and the lens differs from the refractive angle of the signal light when the signal light and the reference light are incident on the optical information storage medium, thereby making the reference light and the signal light different. Interference may occur in the optical information storage medium.
The optical information recording apparatus according to the present invention forms a light source for providing light, a reference light pattern and a signal light pattern for providing the light as a reference light and a signal light, and the reference light pattern is any one of a ring shape, a fan shape, and a circular comb shape. And a lens configured to interfere with the reference light traveling from the light modulator and the signal light in an optical information storage medium to store the optical information.
The optical information reproducing apparatus according to the present invention includes a light source for providing light and an area in which a reference light does not overlap each other in a recording area of an optical information storage medium, so that the light is used as the reference light for multiple reproduction of the multi-recorded optical information. An optical modulator for converting a reference light pattern into a reference light pattern corresponding to the reference light so as to be modulated, a lens for guiding the reference light traveling to an optical information storage medium with the reference light traveling in the same optical axis as the optical axis of the signal light used for recording from the optical modulator; And an optical information detector for detecting the reproduction light reproduced from the optical information storage medium.
In the multi reproduction, the reference light pattern may be formed of a first reference light pattern and a second reference light pattern which have no correlation with each other.
An optical information reproducing apparatus according to the present invention includes a light source for providing light, a reference light pattern for modulating the light into reference light, and an optical modulator for forming the reference light pattern in any one of a ring shape, a fan shape, and a partial comb shape. And a lens for guiding the reference light traveling to the same optical axis as the optical axis of the signal light used for recording from the optical modulator to an optical information storage medium, and an optical information detector for detecting reproduction light reproduced from the optical information storage medium.
The optical information recording method according to the present invention comprises the steps of: modulating the light provided by the signal light pattern and the reference light pattern into signal light and reference light traveling in the coaxial direction with the signal light, and in the optical information storage medium. Recording the optical information by interfering with each other, forming another signal light by different signal light patterns and another reference light by different reference light patterns formed in different regions not overlapping with the reference light pattern for multiple recording; Interfering signal light with the other reference light in the optical information storage medium to record other optical information overlapping the optical information.
The reference light patterns may have a form that is not correlated with each other in multiple recording.
In the multiple recording, the optical information is recorded in the entire recording area of the optical information storage medium with the reference light by the reference light pattern, and then the entire recording area of the optical information storage medium is used with the other reference light by the other reference light pattern. Other optical information can be superimposed.
The multi-recording may record the optical information using a plurality of different reference lights in one recording area of the optical information storage medium, and then record the optical information using the plurality of different reference lights in another recording area.
In the optical information recording method according to the present invention, the provided light is moved coaxially with the signal light and the signal light by a signal light pattern and a reference light pattern formed by any one of a ring shape, a fan shape, a circular comb shape, and a partial comb shape. And modulating the reference light into the reference light, and recording the optical information by interfering the signal light with the reference light in an optical information storage medium.
The optical information reproducing method according to the present invention comprises the steps of: providing light in a reference light pattern formed during recording, injecting the reference light modulated according to the reference light pattern into the optical information recording area of the optical information storage medium, and reproducing the optical information; Providing the light with another reference light pattern that is changed to an area not overlapping with the reference light pattern for reproduction of other recorded optical information by recording another reference light in an area not overlapping with the reference light when recording, And injecting another reference light by the other reference light pattern into the optical information recording area of the optical information storage medium to reproduce the other optical information.
In the multi reproduction, the reference light patterns may have a shape that does not correlate with each other.
The optical information reproducing method according to the present invention comprises the steps of: providing light in a reference light pattern formed of any one of a ring shape, a fan shape, a circular comb shape, and a partial comb shape during recording, and converting the reference light modulated according to the reference light pattern into an optical information storage medium. Incident on the optical information recording area of the optical information recording area to reproduce the optical information.
Hereinafter, an optical information processing apparatus, an optical information recording method, and an optical information reproducing method according to an embodiment of the present invention configured as described above will be described. And the names of each component in the description of the following embodiments may be called other names in the art. However, if the functional similarity and identity thereof, even if the modified embodiment can be adopted may be equivalent configuration. In addition, the symbols added to each component is described for convenience of description. However, the contents shown in the drawings in which these symbols are described do not limit each component to the ranges in the drawings. Similarly, even if an embodiment in which the configuration on the drawings is partially modified is employed, it can be regarded as an equivalent configuration if there is functional similarity and identity.

Hereinafter, an optical information processing apparatus according to an embodiment of the present invention will be described. The following optical information processing apparatus can be implemented only by the optical information reproducing apparatus except for the configuration of the optical detector, while the optical information recording apparatus can be implemented by modifying some components of the optical system except the configuration of the optical modulator. . Therefore, in the following description of the embodiments, the embodiments will be described by the optical information processing apparatus, without being divided into a playback apparatus and a recording apparatus.

1 is a block diagram showing an optical information processing apparatus according to an embodiment of the present invention, Figure 2 shows a progress state of the signal light and the reference light when recording the optical information in the optical information processing apparatus according to an embodiment of the present invention A conceptual diagram.

As shown in FIG. 1 and FIG. 2, the optical information processing apparatus according to the embodiment of the present invention includes a light source 100. The light source 100 may use a red laser of 635 nm-650 nm wavelength or a blue laser of 430 nm wavelength. And a lens 110 for advancing the light provided from the light source 100 into parallel light, and a reflecting mirror 120 reflecting the light passing through the lens 110 at a predetermined angle. It also includes an optical modulator 130 for loading a modulated signal to the light reflected from the reflection mirror 120. The optical modulator 130 uses a digital micromirror device (DMD).

The light modulator 130 provides a signal light pattern 131 and a reference light pattern 132 to modulate the light. Accordingly, the light reflected by the reflective mirror 120 is reflected by the optical modulator 130 and is provided as the signal light S and the reference light R in the coaxial direction. In the light modulator 130, the signal light pattern 131 is formed at the center of the light modulator 130, and the reference light pattern 132 is formed at the periphery of the signal light pattern 131 of the light modulator 130.

And a beam splitter 140 for guiding the signal light S and the reference light R traveling coaxially to the optical information storage medium 190. The beam splitter 140 passes P-polarized light out of the advancing light. The shutter 141 and the photo detector 150 are installed at the side of the beam splitter 140. The photo detector 150 may be a charge-coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), or other optical device capable of detecting light. The shutter 141 is closed when the optical information is recorded, and opened when the optical information is reproduced.

Subsequently, a reflection mirror 160 is provided on the optical axis optical path of the beam splitter 140 to reflect the signal light S and the reference light R to the optical information storage medium 191. After the reflection mirror 160, a wavelength plate (λ / 4 plate) 170 is installed, and after the wavelength plate 170, an object lens 180 is installed. Here, the wave plate 170 changes the P-polarized light transmitted through the beam splitter 140 to S-polarized light. Therefore, light incident to the optical information storage medium 190 via the objective lens 180 proceeds to S-polarized light.

After the objective lens 180, the optical information storage medium 190 is installed. The optical information storage medium 190 may use a photopolymer material. The reflective surface 191 is formed on the opposite surface to which the light of the optical information storage medium 190 is incident. The reflective surface 191 reflects the light passing through the optical information storage medium 190 in the direction in which it was incident again.

Meanwhile, as shown in FIG. 2, the objective lens 180 is provided as a convex lens. Therefore, the signal light S incident to the center portion of the objective lens 180 and the reference light R incident to the peripheral portion of the objective lens 110 have different refraction angles. That is, the angle of refraction of the reference light R when recording optical information is larger than that of the signal light. Therefore, the refracted signal light S and the reference light R intersect at any one point, and the information storage portion of the optical information storage medium 190 is located at this intersection. Accordingly, the hologram is recorded on the optical information storage medium 190 due to the interference between the signal light S and the reference light R during recording. In order to control the focusing position, the objective lens 180 or the optical information storage medium 190 may be controlled by an actuator (not shown).

In an embodiment of the present invention, the optical information detector 150 is located on the side of the coaxial path of light traveling from the optical modulator 130 to the optical information storage medium 190. Therefore, when the optical information is reproduced, the reference light R is incident on the optical information storage medium 190, and then the reproduced light is reflected on the reflecting surface 191 of the optical information storage medium 190 to be incident to the reference light R. It proceeds to the beam splitter 140 via. At this time, since the reproduced light is still S-polarized light, it is reflected by the beam splitter 140 to proceed to the photo detector 150, and the photo detector 150 decodes the information of the reproduced incident light. On the other hand, in another embodiment, the optical detector may be installed in a direction in which the light traveling to the optical information storage medium 190 passes when the optical information is recorded, and at this time, the reflective surface 191 is provided on the optical information storage medium 190. This does not need to be formed.

In the embodiment of the present invention, the reference light pattern 132 is provided in various forms for multiple recording and reproduction of optical information. Here, the multi-recording means that the optical information is recorded in the same place by overlapping, and the multi-playing means reproducing a plurality of optical information recorded in the same place, respectively.

Hereinafter, the reference light pattern 132 formed on the light modulator 130 according to the embodiment of the present invention will be described in more detail. Here, the reference light pattern 132 and the signal light pattern 131 are different regions in the optical modulator 130, and the signal light S and the reference light R generated in each pattern interfere with each other in the optical information storage medium 190. If possible, recording and reproduction of optical information is possible.

3 is a view showing a signal light pattern 131 and a reference light pattern 132 at the time of recording optical information in the optical information processing apparatus according to the embodiment of the present invention. As shown in FIG. 3, the signal light pattern 131 is formed in the central portion of the light modulator 130, and the reference light pattern 132 is formed at a position spaced a predetermined distance from the periphery of the signal light pattern 131. The reference light pattern 132 is provided in the form of an annular comb pattern arranged 360 degrees in the circumferential direction. In addition, the reference light pattern 132 may be provided in a variety of forms, thereby allowing multiple recording and reproduction of optical information.

4A and 4B illustrate reference light patterns 132 of the optical modulator 130 when multiplexing optical information according to an exemplary embodiment of the present invention. As shown in FIGS. 4A and 4B, the deformation of the reference light R is performed by changing the formation angle of each comb pattern forming the reference light pattern 132. That is, if the separation angle between the comb patterns is "θ, (θ is 360 / the number of comb patterns)", the entire comb pattern is "θ _r , (0 <Θ _r <θ) "can be rotated to, and therefore it is possible to obtain a different type of hatch reference light pattern 132 'does not have correlation to each other. Other forms of the reference light pattern at this time is" θ _r, (0 <? _r <?) " can be obtained. Therefore, the optical information can be multiplexed by the first reference light pattern 132 and the second reference light pattern 132 'formed by the respective comb teeth.

An experimental example thereof will be described below.

In this experiment, the angle between each comb pattern is 12 degrees, the thickness of the storage medium 190 is 200 um, the wavelength of light used is 405 nm, and the focal length of the objective lens 110 is 5 mm or more. It was concluded that multiplexing of optical information is possible when the reference light pattern 132 is rotated at a rotation angle. This result is demonstrated in the following description. The following graphs are the results obtained according to the experimental example mentioned according to the embodiment of the present invention.

5 is a graph showing diffraction efficiency with respect to the pattern rotation angle of the symbol light according to an embodiment of the present invention, Figure 6 is a graph showing the noise rate for the pattern rotation angle of the reference light according to an embodiment of the present invention, 7 is a graph showing the correlation between the thickness of the optical information storage medium and the diffraction efficiency.

First, as shown in FIG. 5, the diffraction efficiency of the optical information recorded by 30 comb patterns having angles of 12 degrees from each other was measured. The diffraction efficiency according to the rotation angle was about 0.5% when the diffraction efficiency was about ± 2 degrees or more. In addition, as shown in FIG. 6, the signal-to-noise ratio (SNR) is also significantly reduced to about multiple degrees when the signal-to-noise ratio (SNR) is about ± 2 degrees or more. Therefore, as in the present experimental example, when the angle between the comb patterns is 12 degrees, it can be seen that the multiplexing of optical information is possible by rotating the comb patterns at a rotation angle of 2 degrees. In addition, this result can find a rotation angle for forming another comb pattern according to the angle between the comb patterns, which are the reference light patterns 132, and based on this, multiple recording and reproduction of optical information is possible.

On the other hand, noise generated by the multiplexing of the reference light patterns 132 and 132 'is not completely eliminated. However, solving the problem of this noise can be effectively overcome by increasing the thickness of the optical information storage medium 190. 7 shows diffraction efficiency with respect to the thickness of the storage medium 190 when shifting according to the thickness of optical information. As shown in FIG. 7, when the storage medium 190 has a thickness of 300 μm, 600 μm, or 1200 μm, when the moving distance is 0, the diffraction efficiency of the storage medium 190 having a thickness of 1200 μm is best, and then stored. When the medium 190 is moved, the diffraction efficiency of the storage medium 190 having a thickness of 1200 μm decreases rapidly according to the moving distance, and thus the lowest diffraction efficiency is exhibited at a position of about 0.8 μm. Therefore, based on this, it can be seen that increasing the thickness of the optical information storage medium 190 generates a lower noise, thereby finding a more optimal optical information multiple recording position.

FIG. 8A is a photograph showing a result of reproducing optical information when the rotation angle of the reference light pattern is "0 degree" as an experimental example according to an embodiment of the present invention, and FIGS. 8B to 8E are embodiments of the present invention. As an experimental example, it is a photograph showing the reproduction result of the optical information when the rotation angle of the reference light pattern is "2 degrees", "4 degrees", "6 degrees", and "8 degrees", respectively.

As mentioned above, the experimental conditions for the results of the experiment are as described above, forming 30 comb patterns with the angle between each comb pattern to 12 degrees, the thickness of the storage medium 190 being 200 um, the wavelength of the light used being 405 nm, the objective. This is for the case where the focal length of the lens 110 is set to 5 mm. Recorded data was input and reproduced as analog signals for easier identification and understanding. In order to distinguish the reproduced optical information, "A" in FIG. 8A, "B" in FIG. 8B, "D" in FIG. 8C, "E" in FIG. 8D, and "F" in FIG. 8E were recorded and reproduced. The comb pattern used for recording was reproduced together. According to this result, it can be seen that each optical information is effectively reproduced at the rotation angle of the comb patterns of 2 degrees.

9A and 9B illustrate reference light patterns in an optical modulator when multiplexing optical information according to another embodiment of the present invention. As illustrated, the first reference light pattern 134 and the second reference light pattern 134 ′ may be formed in a fan shape. As shown in FIG. 9A, two fan-shaped first reference light patterns 134 are formed at positions 90 and 270 degrees outside the signal light pattern 133 and used for recording or reproducing optical information. When multiplexing the second reference light pattern 134 ′, as shown in FIG. 9B, the second reference light pattern 134 ′ may be formed at positions 0 and 180 degrees to allow multiple recording or reproduction of optical information. These locations are mentioned by way of example, the shape, size, location may be modified in more various ways.

10A and 10B illustrate a pattern of reference light according to another exemplary embodiment of the present invention. As illustrated, the first reference light pattern 136 may be formed in a ring shape on the outside of the signal light pattern 135. As shown in FIG. 10A, a ring-shaped first reference light pattern 136 is formed around the signal light 135 to be used when recording or reproducing optical information, and when multiplexing the second reference light pattern 136 ′. As shown in FIG. 10B, the first reference light pattern 136 may be formed to have another aperture at another position outside the first reference light pattern 136, and may be formed to have another aperture.

As in the above embodiments, the shape of the reference light pattern may be modified in various forms if the respective reference light patterns do not correlate with each other when multiplexed. In this case, the non-correlation means that the light modulator 130 does not overlap another reference light pattern at the same pixel or position. The separation distance between the reference light patterns or the separation between the reference light signal and the signal light pattern may be variously implemented according to the numerical aperture of the objective lens 180. In other words, if the numerical aperture is large, the resolution is high, so that the interval can be made compact. If the numerical aperture is small, the resolution is low, so the interval can be widened.

On the other hand, Figure 11 is a block diagram showing an optical information processing apparatus according to another embodiment of the present invention. As illustrated in FIG. 11, an optical information processing apparatus according to another exemplary embodiment includes a light source 200. And a lens 210 for advancing the light provided from the light source 200 into parallel light, and the reference light pattern 132 and the signal light pattern 131 in the first embodiment described above from the light passing through the lens 110. In addition, the light modulator 220 is formed to form the reference light (R) and the signal light (S).

This light modulator 220 is composed of LCD. The LCD constituting the optical modulator 130 is a typical TFT LC (thin film transistor liquid crystal) of an active matrix, a super twisted nematic liquid crystal (STN LC) of a passive matrix, a ferroelectric crystal (LC), a polymer dispersed LC ( Polymer Dispersed Liquid Crystal (PDLC) and plasma addressed liquid crystal (PALC) may be employed.

In the light modulator 220, the signal light pattern 131 is formed at the center of the light modulator 130, and the reference light pattern 132 is formed at the periphery of the signal light pattern 131 of the light modulator 130 (FIG. 2). Reference). And a beam splitter 230 for guiding the signal light S and the reference light R traveling coaxially from the optical modulator 220 to the optical information storage medium 270. The beam splitter 230 passes the P-polarized light of the advancing light and reflects the S-polarized light. The shutter 280 and the photo detector 290 are provided at the position where the S-polarized light is reflected. The photo detector 150 may be a charge-coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), or other optical device capable of detecting light. The shutter 280 is closed when the optical information is recorded and opened when the optical information is reproduced.

A reflection mirror 240 is installed after the beam splitter 230, and a wavelength plate λ / 4 plate 250 and an objective lens 260 are respectively installed in a direction in which the light is reflected by the reflection mirror 240. Wave plate 250 converts the provided P polarization into S polarization. Therefore, light incident on the optical information storage medium 270 via the objective lens 260 proceeds to S-polarized light. In addition, a reflective surface 271 is formed on the opposite surface to which the light of the optical information storage medium 270 is incident to reflect the light passing through the optical information storage medium 270 in the incident direction. Therefore, the reproduced light at the time of reproduction of the optical information is reflected on the reflective surface and proceeds to the photodetector 290 side. At this time, the operation state may refer to the above-described embodiment.

Hereinafter, an optical information recording method and an optical information reproducing method according to an embodiment of the present invention will be described. The description of the following methods may refer to the configuration of the above-mentioned optical information processing apparatus, or may also be performed in the optical information processing apparatus of another modified embodiment having the same or similar technical concept as the above-described optical information processing apparatus. have. The structure of the optical information processing apparatus referred to in the description of the following embodiments can be understood with reference to the first embodiment shown in FIGS. 1 and 2.

12 is a flowchart showing an optical information recording method according to an embodiment of the present invention. As shown in FIG. 12, in the optical information recording method according to the embodiment of the present invention, the light provided from the light source 100 is advanced to the optical modulator 130 to reflect the reference light R and the signal light S in the coaxial direction, respectively. (S10).

The reference light R and the signal light S are divided in the coaxial direction by the reference light pattern 132 and the signal light pattern 131 formed in one optical modulator 130 and proceed to the optical information storage medium 190. In detail, the signal light pattern 131 is formed at a central portion of the light modulator 130, and the first reference light pattern 132 is formed to be separated by a predetermined interval around the signal light pattern 131.

Thereafter, the reference light R and the signal light S provided by the optical modulator 130 are incident on the optical information storage medium 190 via the signal light S and the objective lens 110. In this case, the signal light S is incident to the center portion of the objective lens 110, and the reference light R is incident to the peripheral portion of the objective lens 110. However, since the convex lens 110 is adopted, the objective lens 110 focuses the light onto the optical information storage medium 190. That is, since the angle of refraction of the signal light S traveling to the center of the objective lens 110 and the angle of refraction of the reference light R traveling to the peripheral portion of the objective lens 110 are different from each other, the reference light R and the signal light S are different. Is focused on the recording area inside the storage medium 190. Accordingly, as shown in FIG. 2, optical information of the signal light S is recorded due to interference between the reference light R and the signal light S (S11).

On the other hand, multiple recording of the optical information changes the reference light pattern 132 of the optical modulator 130 forming the reference light R into a second reference light pattern 132 ′ having a non-correlation shape (S12). The data of the different signal lights S can be multiplely recorded in the same place (S13). In this case, the reference light patterns 132 and 132 ′ may be formed by a ring shape, a fan shape, a circular comb shape, or a partial comb shape.

In the multi-recording operation, the first reference light pattern 132 has a ring shape having a different aperture from the second reference light pattern 132 ', a fan shape formed at a different position, or a circular comb shape arranged at different angles. Or a partial comb tooth formed at another position, or the like, and may be formed in various other forms.

When the optical information is multi-recorded while changing the shape of the reference light patterns 132 and 132 ', two methods may be used. First, recording is performed while changing the optical information of the signal light S with the reference light R formed in the first reference light pattern 132 in the entire recording area of the storage medium 190. Thereafter, the optical information may be superimposed on the entire recording area of the storage medium 190 by changing the optical information of the signal light S using the second reference light pattern 132 ′ for multiplexing.

Another method is to superimpose optical information using reference light R made of a plurality of different reference light patterns 132 and 132 'in one recording area of the storage medium 190, and then to record a plurality of different information in another recording area. By using the reference light R, the optical information can be superimposed.

13 is a flowchart illustrating a method of reproducing optical information according to an embodiment of the present invention. As shown in FIG. 13, the optical information reproducing method provides light to the optical modulator 130 in which the reference light pattern 132 is formed at a position around the signal light pattern 131 at the time of recording (S20). The first reference light pattern 132 is formed in the same manner as in the aforementioned optical information recording method. The light passing through the optical modulator 130 is incident on the optical information recording position of the optical information storage medium 190 to reproduce the optical information (S21).

Then, after changing the shape of the reference light pattern 132 ′ in the optical modulator 130, the light is again provided to the optical modulator 130 (S22). Then, another reference light R having no correlation is generated by the second reference light pattern 132 ′ generated through the optical modulator 130. The other reference information R reproduces the other optical information at the optical information recording position of the optical information storage medium 190 (S23).

On the other hand, the reference light patterns 132 and 132 'for reproducing the optical information should be provided in the same form as the reference light patterns 132 and 132' used for recording the optical information. In other words, if the reference light patterns 132 and 232 'are used for recording in either form, the same reference light patterns 132 and 132' as those used for recording should be used for reproduction of the corresponding optical information. It should be noted that the same here means that light having the same or similar properties, that is, the same reference light pattern, phase, and wavelength is set to be provided, but not through the same optical system in the same light source.

In the optical information processing according to the embodiment of the present invention as described above, when the optical information is incident on the optical information storage medium coaxially with the reference light and the signal light, the optical information can be overlaid on the storage location of the same optical information so that the multiple information can be recorded. The recording density of the optical information can be further increased.

In the optical information processing apparatus, the optical information recording method, and the optical information reproducing method according to the embodiment of the present invention described above, a part or a part of the method may be modified by a person skilled in the art and implemented differently. However, all other modified embodiments include the essential elements of the present invention should be considered to be included in the technical scope of the present invention.

The optical information processing apparatus, the optical information recording method, and the optical information reproducing method according to the present invention as described above allow the reference light and the signal light to move coaxially to record the optical information, and the patterns of the reference light are varied with other reference light patterns having no correlation with each other. In this case, the optical information processing apparatus using the coaxial optical system is used to more effectively multiplex the optical information, thereby improving the storage density and use efficiency of the holographic optical information.

Claims (23)

A light source for providing light; Forming a reference light pattern and a signal light pattern for modulating the light into a reference light and a signal light, and the reference light pattern is modulated in another area where the reference light is not overlapped with each other when optical information is recorded in a recording area of an optical information storage medium. Varying light modulators; And a lens configured to interfere with the reference light from the optical modulator and the signal light in the optical information storage medium to store the optical information. The method of claim 1, wherein the reference light and the signal light is incident on the lens in the coaxial direction, the lens is different from the refractive angle of the signal light when the signal light and the reference light is incident on the optical information storage medium And the interference between the reference light and the signal light is made in the optical information storage medium. A light source for providing light; An optical modulator for forming a reference light pattern and a signal light pattern for providing the light to the reference light and the signal light, and forming the reference light pattern in any one of a ring shape, a fan shape, and a circular comb shape; And a lens for interfering with the reference light and the signal light traveling from the optical modulator in an optical information storage medium to store the optical information. A light source for providing light; In the recording area of the optical information storage medium, the reference light pattern is changed into a reference light pattern corresponding to the reference light so that the light is modulated into the corresponding reference light for multiple reproduction of the multi-recorded optical information recorded in an area where reference light does not overlap each other. An optical modulator; A lens for guiding the reference light traveling to the optical information storage medium to the same optical axis as the optical axis of the signal light used for recording from the optical modulator; And an optical information detector for detecting reproduction light reproduced from the optical information storage medium. The optical information reproducing apparatus according to claim 4, wherein the reference light pattern is formed of a first reference light pattern and a second reference light pattern having a non-correlation shape when multiple reproduction is performed. A light source for providing light; An optical modulator for forming a reference light pattern for modulating the light into reference light, and for forming the reference light pattern in any one of a ring shape, a fan shape, and a partial comb shape; A lens for guiding the reference light traveling to the optical information storage medium to the same optical axis as the optical axis of the signal light used for recording from the optical modulator; And an optical information detector for detecting reproduction light reproduced from the optical information storage medium. Modulating the provided light by the signal light pattern and the reference light pattern into the signal light and the reference light traveling in the coaxial direction with the signal light; Recording optical information by interfering the signal light with the reference light in an optical information storage medium; Forming, for multiple recording, another signal light by different signal light patterns and another reference light by another reference light pattern formed in another area which does not overlap with the reference light pattern; And recording other optical information overlapping the optical information by interfering the other signal light with the other reference light in the optical information storage medium. 8. The optical information recording method according to claim 7, wherein the reference light patterns do not correlate with each other during multiple recording. 8. The method of claim 7, wherein the multiple writes are The optical information is recorded in the entire recording area of the optical information storage medium with the reference light by the reference light pattern, and then the other optical information is recorded in the entire recording area of the optical information storage medium with the other reference light by the different reference light pattern. Optical information recording method characterized in that the superimposition recording. 8. The method of claim 7, wherein the multi-recording records the optical information using a plurality of different reference lights in one recording area of the optical information storage medium, and then uses the plurality of different reference lights in another recording area. Optical information recording method characterized in that the recording. Modulating the provided light by the signal light pattern and the reference light pattern coaxially with the signal light by the reference light pattern formed by any one of a ring shape, a fan shape, a circular comb shape, and a partial comb shape; And recording the optical information by interfering the signal light with the reference light in an optical information storage medium. Providing light in a reference light pattern formed during recording; Reproducing optical information by injecting a reference light modulated according to the reference light pattern into an optical information recording area of an optical information storage medium; Providing the light in a different reference light pattern which is changed to an area not overlapping with the reference light pattern for reproduction of other recorded optical information by recording another reference light in an area not overlapping with the reference light when recording; And injecting another reference light by the other reference light pattern into the optical information recording area of the optical information storage medium to reproduce the other optical information. The optical information reproducing method according to claim 12, wherein the reference light patterns do not correlate with each other during multiple reproduction. Providing light in a reference light pattern formed in any one of a ring shape, a fan shape, a circular comb shape, and a partial comb shape during recording; And inputting the reference light modulated according to the reference light pattern into an optical information recording area of the optical information storage medium to reproduce the optical information. delete delete delete delete delete delete delete delete delete

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