KR100787754B1 - Optical information recording method, optical information reproducing method, optical information control method - Google Patents

Abstract

The optical information recording method of the present invention includes the steps of injecting a signal light loaded with data into an optical information storage medium, and using a reference light having a different offset angle for each track to form a plurality of tracks having a recording area on the optical information storage medium. And entering a multiple angle and forming a recording area by changing the reference light to an angle within a marginal angle range when the multiple angle is greater than or equal to the limitable angle. The optical information recording method of the present invention includes a recording area portion. To increase the optical information recording density, to enable servo control by using adjacent regenerated light as the servo control light, and to change the reference light to an angle within the limit angle range at an angle greater than or equal to the limit angle, thereby storing the storage capacity of the optical information storage medium. It is effective to increase.

Description

Optical information recording method, optical information reproducing method, optical information control method {Optical information recording method and optical information reproducing method and optical information servo control method}

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

Fig. 2A is a simplified diagram showing the overlapping limit of the recording area due to the increase of the track in the optical information storage medium.

2B is a simplified diagram showing a state where the recording areas are overlapped according to the recording method according to the embodiment of the present invention.

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

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

FIG. 5 is a graph showing a comparison of the amount of reproduction light generated in adjacent tracks when the optical information of a track selected by the optical information processing apparatus according to the embodiment of the present invention is reproduced.

FIG. 6 is a flowchart illustrating a method of performing servo control according to FIG. 5.

The present invention relates to an optical information processing method. More specifically, the reference light is incident on a plurality of tracks at different offset angles, and the optical information is changed by changing the reference light to an angle within the limit angle range at an angle above the limit while recording and reproducing the optical information. The present invention relates to an optical information processing method for recording and reproducing and performing servo control using reproduction light of another track reproduced in a recording area adjacent to a selected recording area.

In the information age, various industries that have developed independently have converged and transformed into the multimedia industry, and the information volume has increased exponentially due to the establishment of information service base. Therefore, the necessity of a storage device capable of processing data at high speed and super capacity is rapidly increasing.

The three-dimensional holographic optical information storage technology, which has recently been in the spotlight among these data processing technologies, can store and process data in parallel at the same time, and the processing speed is high and the data is distributed and stored so that even when the hologram at the recorded point is damaged The damaged optical information can be restored and reproduced. The data recording of the holographic light processing apparatus is performed by recording an interference pattern generated by superimposing the optically modulated signal light and a reference light inside the recording medium, and reproducing the stored data by irradiating only the reference light to the storage medium. By diffraction occurring.

In addition, the holographic optical information processing apparatus can store data spatially by a multiplexing technique. Such multiplexing techniques include angular multiplexing, phase code multiplexing, wavelength multiplexing, and shift. Shift multiplexing, and the like. Mixing and recording these multiplexing techniques increases the recording density, which makes it possible to store optical information with extra large capacity.

Prior art for recording optical information by such a multiplexing technique includes a "holographic information recording / reproducing apparatus" of the Korean patent "10-2005-0102748". However, when the optical information is recorded by using the multiplexing technique, the recording area is superimposed to increase the recording density. Therefore, it is difficult to irradiate the reference light only to the recording area to be irradiated when the optical information is reproduced. Can be. It is important to block the optical information reproduced in such an adjacent recording area because the reproduction efficiency of the optical information to be detected decreases. Prior art for this is US Patent "2004-0179251" "Progress of the Developement of High Performance Removable Storage at InPhage Technologies for Application to Archival Storage". The patent uses a filter to block light being reproduced in unselected areas. In addition, in order to detect accurate optical information, servo control is required, and prior arts thereof include "Optical information recording apparatus and optical information reproducing apparatus" of US Patent "2005-0030876". The patent uses a separate laser light source for servo control.

Accordingly, the configuration of the optical system and the device for the servo control is complicated, and the configuration of the optical information storage medium is complicated because a separate light source for the servo control is to be separately installed.

An object of the present invention is to provide an optical information processing method that enables servo control for optical information reproducing by detecting reproduced light reproduced in an adjacent recording area around a selected recording area when optical information is reproduced without using a separate servo control light. It is to provide.

SUMMARY OF THE INVENTION An object of the present invention is to irradiate reference light having different offset angles to each track when recording and reproducing optical information on a track having a plurality of recording areas, and to change the reference light to an angle within the limit range at an angle greater than or equal to the limit angle. An optical information processing method for recording and reproducing is provided.

The optical information recording method according to the present invention for achieving the above object is a step of injecting a signal light loaded with data on the optical information storage medium, the track to form a plurality of tracks having a recording area on the optical information storage medium And injecting a reference light having a different offset angle at every multiple angle, and changing the reference light to an angle within a marginal angle range when the multiple angles are equal to or greater than the allowable limit angle to form a recording area.

The recording area located on the track and the recording area adjacent to the recording area may partially overlap.

The innermost track and the outermost track among the tracks may be formed as dummy tracks in which dummy data is recorded only for diffraction reproduction of light.

Multiple angles of the reference light and the offset angle may be incident while changing from a small angle to a large angle.

When the angle above the limit angle is changed to an angle within the limit angle range, the incident angle may be changed while changing from a large angle to a small angle.

The optical information reproducing method according to the present invention for achieving the above object comprises the step of injecting a reference light having a larger area and entering a limit angle at which the incident light is extended to a storage medium having a plurality of recording areas adjacent to each other; And entering the reference light by changing an angle of incidence to an angle within the limit angle range when the angle reaches the threshold angle or more, detecting adjacent reproduced light reproduced in a recording area adjacent to the selected recording area, and light of the adjacent reproduced light. Controlling the reproduction conditions of the selected reproduction light reproduced in the selected recording area by using the information, and detecting the selection reproduction light.

The reproduction condition may be any one of an incident angle of the reference light and a tilting state of the optical information storage medium.

The recording areas form a plurality of tracks having different diameters, and the reference light may be incident at multiplexing angles having different offset angles for each track.

The detection of the reproduction light may be performed in the remaining tracks except for the innermost track and the outermost track of the optical information storage medium.

Multiple angles of the reference light and the offset angle may be incident while changing from a small angle to a large angle.

When the angle is changed within the range of the angle above the limit angle can be incident while changing from a large angle to a small angle.

The optical information of the adjacent reproduction light may be an amount of light.

The control method of the optical information processing apparatus according to the present invention for achieving the above object is a limit that can be incident to the reference light having a larger area, including one recording area selected on the optical information storage medium having a plurality of recording areas adjacent to each other Incidence to an angle, incidence of the reference light by changing the incidence angle to an angle within the limit angle range when the angle reaches the angle greater than or equal to the limit angle, detecting adjacent reproduction light reproduced in a recording area adjacent to the selected recording area; Comparing the optical information of the adjacent reproduction light to control the reproduction condition of the reproduction light.

The reproduction condition may be any one of an incident angle of the reference light and a tilting state of the optical information storage medium.

Hereinafter, an embodiment of an optical information processing apparatus according to the present invention will be described. 1 is a schematic diagram showing an optical information processing apparatus according to an embodiment of the present invention. As shown in FIG. 1, an optical information processing apparatus according to an exemplary embodiment of the present invention includes a light source 100, and includes a first light splitter 110 that separates light emitted from the light source 100 into signal light and reference light. Include.

The first light splitter 110 is a polarized light splitter and transmits a signal light (S wave) having a property of horizontal polarization (S-Polarization) in a direction of 90 degrees, and a reference light having a property of vertical polarization (P-Polarization). Wave) is transmitted as it is. In the path of the reference light separated from the light by the first light splitter 110, a rotation mirror 120 for injecting the reference light into the optical information storage medium 210 is disposed. The rotating mirror 120 may use a galvano mirror for irradiating the reference light at multiple angles.

Subsequently, a reflection mirror 130 is disposed in the path of the signal light separated from the light by the first light splitter 110 to guide the signal light to the optical expander 150. The optical expander 150 expands the light so that the signal light can be expanded to fit the size of the optical modulator 160 to load data. A shutter 140 is provided between the optical expander 150 and the reflection mirror 130 and is opened when optical information is recorded to pass the signal light, and is shielded when optical information is reproduced to block the signal light. Subsequently, an optical modulator 160 for loading optical information data is disposed. After the optical modulator 160, the lenses 170a and 170b and the first filter 180 are installed. The first filter 180 removes spike noise from the light passing through the lens 170a to form light having a flat intensity distribution.

After the first filter 180, the λ / 2 polarizer 190 is placed to convert the signal light into P-polarized light, which is then Fourier transformed by the first Fourier transform lens 200 to be incident on the storage medium 210. The storage medium 210 may be a photopolymer-based material.

After the storage medium 210, two lenses 220a and 220b for focusing the reproduced light are disposed, and the second light splitter 230 and the λ / 4 polarizer 240 are disposed between the lens 220a and the lens 220b. ) Is placed. The λ / 4 polarizer 240 is used to select light in the required polarization direction and converts the P-polarized regenerated light, which is reproduced in the storage medium 210, into S-polarized light when reflected from the second filter 250 and returned. Do it.

The second filter 250 is disposed after the second lens 220b, and the second Fourier transform lens 260 is disposed after the second filter 250. The second filter 250 has a hole 251 to pass only the reproduction light of the selected recording area in the center, and a reflective layer 252 is formed on the surface to reflect the adjacent reproduction light generated in the adjacent recording area.

Subsequently, the reproduced light of the selected recording area passing through the second filter 250 is detected by the arranged reproduced light detector 270. The reproduction light detector 270 may use an image recognition device composed of a pixel array such as a charge-coupled device (CCD) or a complementary (CMOS).

Adjacent regenerated light of the P-polarized light reflected by the reflective layer of the second filter 250 is changed into S-polarized light while passing through the λ / 4 polarizer 240 and transmitted in the 90-degree direction by the second light splitter 230, and the adjacent regenerated light is transmitted. Is detected by the adjacent reproduction light detector 290 through the lens 280 to guide the adjacent reproduction light detector 290. The adjacent reproduction light detector 290 may be formed of a photodiode.

Thereafter, the optical information detected by the adjacent reproduction light detector 290 is transmitted to the control unit 300, and the control unit 300 analyzes the optical information of the adjacent reproduction light and rotates the rotation mirror 120 or the optical information storage medium 210. It can control the tilting state of.

2A is a simplified diagram showing an overlap limit of an optical information storage medium recording area, and FIG. 2B is a simplified diagram showing a state where the recording areas are overlapped according to a recording method according to an embodiment of the present invention.

As shown in Figs. 2A and 2B, the respective recording areas are partially overlapped with recording areas adjacent to each other, that is, adjacent recording areas of the same track and adjacent recording areas between different tracks. In other words, it is recorded in the form of shift multiplexing.

This recording method is to increase the recording density of the optical information, and can perform the servo control necessary for reproducing the optical information with the adjacent reproduction light reproduced in the adjacent recording area instead of the selected recording area. The embodiment of FIG. 2A will be described in detail with reference to Table 1. FIG.

Track 1 2nd track 3rd track ... Track 50 ... 100th track First recording area 0.01 degree 0.02 degrees 0.03 0.50 1.00 Second recording area 0.11 degrees 0.12 0.13 0.60 1.10 Third recording area 0.21 degrees 0.22 0.23 0.70 1.20 Fourth recording area 0.31 degrees 0.32 0.33 0.80 1.30 ... 11th recording area 1.01 degrees 1.02 1.03 1.5 2.00

Table 1 exemplarily shows the multiplexing angle when multiple tracks are formed on the optical information storage medium and 11 recording areas are formed on each track. As shown in Table 1, neighboring recording areas in the same track are multiplexed at an angle of 0.1 degrees. The recording area of each track has a different offset angle.

That is, the first track has an offset angle of 0.01 degrees, the second track has an offset angle of 0.02 degrees, the third track has 0.03 degrees, and the 100 track has an offset angle of 1.00 degrees. This means that optical information is recorded at a multiplexing angle by using an offset angle having a difference of 0.01 degrees for each track. In this case, the first track and the last track of the optical information storage medium are dummy tracks having dummy data, and are tracks for servo control in which substantial optical information is not recorded.

In the case of Table 1, the recording area was formed by changing the offset angle for each track by 0.01 degrees. The offset angle between tracks can be set according to the angle selectivity curve. When the difference between the offset angles between tracks is large, the amount of light to be reproduced from the tracks surrounding the selected track is small, and the offset angle between tracks is different. If is small, it is not easy to adjust the angle of the rotating mirror, so the difference of proper offset angle is important.

However, in the case of the optical information storage medium 210 having a plurality of tracks, even if the offset angle between tracks is set properly, the limit track that can form the recording area, that is, the range where the actuator and the lens for adjusting the angle can adjust the angle It is difficult to form a recording area on the remaining tracks except the tracks inside.

For example, when the angle is easily adjusted, that is, the limit angle is 1.50 degrees, the 50th track has an offset angle of 0.50, the first recording area is 0.50 degrees, the second recording area is 0.60 degrees, and the third recording area. Is 0.70 degrees, the fourth recording area is 0.80 degrees, the fifth recording area is 0.90 degrees, the sixth recording area is 1.00 degrees, the seventh recording area is 1.10 degrees, the eighth recording area is 1.20 degrees, and the ninth recording area is 1.30 degrees. Also, the tenth recording area is formed at 1.40 degrees and the eleventh recording area is formed at 1.50 degrees.

Therefore, from the first track to the 50th track, both the first recording area and the eleventh recording area can be formed, but the 51st track has a limit angle because the first recording area starts at 0.51 degrees and has a value of 1.51 degrees in the eleventh recording area. The eleventh recording area cannot be formed beyond 1.50 degrees.

With this limit angle, the first recording area to the tenth recording area from the 51st track to the 60th track, the first recording area to the ninth recording area from the 61st track to the 70th track, and the first track from the 71st track to the 80th track In the recording area to the eighth recording area, the 81st tracks to the 90th tracks, only the first recording area to the sixth recording area are formed from the first recording area to the seventh recording area and the 91th to 100th tracks.

Therefore, in order to utilize the storage capacity of the storage medium, it is important to form another recording area by changing the irradiation angle of the reference light at an angle within the limit angle range as shown in FIG. 2B. The angle of change allows multiplexing of adjacent recording areas within the same track by 0.1 degrees, so as to distinguish the difference between the selected track and the amount of reproduction light from the surrounding tracks when playing the optical information recorded on the track. Adjacent recording areas are preferably recorded at 0.01 degree intervals.

For example, in the case of the 100th track, since the first recording area is formed from 1.00 degrees, there is no recording area utilizing an angle less than the limit of 0.01 degrees to 0.99 degrees. Therefore, after the first to sixth recording areas are formed, additional recording areas are formed in the order of the twelfth recording area (0.90 degrees), the thirteenth recording area (0.80 degrees), the fourteenth recording area (0.70 degrees), and the like. The storage capacity of the storage medium can be further utilized when the track and recording area are increased.

3 is a flowchart illustrating a method of recording optical information according to an embodiment of the present invention. As shown in FIG. 3, in the optical information recording method according to the exemplary embodiment of the present invention, a signal light loaded with data is first incident on the optical information storage medium 210 (S100). Thereafter, in order to generate the storage medium 210 having a plurality of recording areas, reference light having different offset angles is incident at multiple angles in each track (S110).

Subsequently, when the angle of the reference light reaches the limit angle at which the incident light can be incident (S120), the incident angle of the reference light is changed to an angle within the limit angle range (S130) to enter the storage medium 210, and a recording area is formed (S140).

4 is a flowchart illustrating a method of reproducing optical information according to an embodiment of the present invention. As shown in FIG. 4, the reference light including one recording area selected in the optical information storage medium 210 having a plurality of recording areas adjacent to each other and having a larger area is irradiated to a limitable angle of incidence (S200). .

Then, when the angle reaches more than the limit angle (S210) is changed to an angle within the limit angle range to enter the reference light (S220). At this time, since the area of the reference light is larger than that of the selected recording area, the reproduction light is generated in the adjacent recording area.

Adjacent reproduction light of the selected recording area and adjacent reproduction light of the recording area are generated in the optical information storage medium 210 and proceed to the filter 250. The reproduction light of the selected recording area passes through the hole 251 of the filter. Adjacent regenerated light is reflected at reflective layer 252 on the filter surface.

Subsequently, the adjacent reproduced light reflected is detected by the adjacent reproduced light detector 290 (S230), and the reproducing condition of the selected reproduced light is controlled according to the light information of the adjacent reproduced light (S240) to detect the optical information of the selected reproduced light (S250). Is done.

Light information detected by the adjacent reproduction light detector 290 is referred to FIG. 5 described below. FIG. 5 is a graph showing a comparison of the amount of reproduction light generated in adjacent tracks when the optical information of a track selected by the optical information processing apparatus according to the embodiment of the present invention is reproduced.

When the reference light including the selected recording area is further expanded to the selected recording area of the optical information storage medium 210, the reproduction light of not only the selected recording area but also the adjacent recording area adjacent to the selected recording area is generated. This is because a portion of the recording area and a portion of the adjacent recording area are superimposed on the storage medium 210 to increase the recording density.

However, since the angle at which the maximum light amount can be detected in the selected recording area and the angle at which the maximum light amount can be detected in the adjacent recording area are different, the difference in the light amount can be compared.

Comparing the amount of light detected in the respective tracks, the first recording area of the first track has the largest diffraction efficiency at an angle of 0.01 degrees, the first recording area of the second track is 0.02 degrees, and the first recording area of the third track. Has the largest diffraction efficiency at 0.03 degrees.

For example, when reproducing optical information of the first recording area formed on the second track, when the reference light is irradiated at an angle of incidence of exactly 0.02 degrees, the amount of light I2 of the selected reproduction light generated in the second track is determined by the first and third tracks. The light amounts I1 and I3 of the adjacent reproduction light to be reproduced are greater than the amounts I1 and I3 of the adjacent reproduced light and the light amounts I1 and I3 of the reproduced light generated in the first and third tracks have similar values.

However, when the angle of inclination is shifted or changed in one direction, the difference in the amount of light I1 and I3 of the reproduction light generated in the first and third tracks becomes large. This phenomenon may be affected not only by the angle of irradiation, but also by the tilting and contracting states of the optical information storage medium.

Therefore, the controller 300 may analyze the optical information of the reproduction light generated in the first track and the third track, and adjust the incident angle according to the optical information to accurately detect the optical information of the reproduction light generated in the second track. .

FIG. 6 is a flowchart illustrating a method of performing servo control according to FIG. 5.

First, a reference light having a larger area is irradiated to a limitable angle, including one recording area selected in the optical information storage medium 210 having a plurality of recording areas adjacent to each other (S300). Then, when the angle reaches more than the limit angle (S310) is changed to an angle within the limit angle range and the reference light is incident (S320).

At this time, since the area of the reference light is larger than that of the selected recording area, the reproduction light is generated in the adjacent recording area. Adjacent reproduction light of the selected recording area and adjacent reproduction light of the recording area are generated in the optical information storage medium 210 and proceed to the filter 250. The reproduction light of the selected recording area passes through the hole 251 of the filter. Adjacent regenerated light is reflected at reflective layer 252 on the filter surface.

The optical information of the adjacent reproduction light is detected by the adjacent reproduction light detector (S330) and used for servo control. Subsequently, servo control to the correct position is performed according to the difference in the amount of light of adjacent reproduction lights (S340).

The optical information processing method according to the present invention as described above increases the optical information recording density by overlapping portions of the recording area, enables the servo control by using the adjacent reproduction light as the servo control light, and at an angle greater than or equal to the limit angle, within the limit angle range. By changing the angle to the reference light to increase the storage capacity of the optical information storage medium.

Claims (14)

Injecting a signal light having data loaded onto the optical information storage medium; Incident reference light having a different offset angle for each track at multiple angles to form a plurality of tracks having a recording area in the optical information storage medium; And And changing the reference light to an angle within the limit angle range when the multiple angles are equal to or greater than the limitable angle of incidence to form a recording area. The optical information recording method according to claim 1, wherein the recording area located on the track and the recording area adjacent to the recording area are partially overlapped. The optical information according to claim 1, wherein the track located at the innermost side of the optical information storage medium and the track located at the outermost side are formed as dummy tracks in which dummy data is recorded only for diffraction reproduction of light. How to record. The optical information recording method according to claim 1, wherein the multiple angles of the reference light and the offset angle are incident while changing from a small angle to a large angle. The optical information recording method according to claim 1, wherein when the angle greater than or equal to the limit angle is changed to an angle within the limit angle range, the incident light is changed while changing from a large angle to a small angle. Injecting a reference light having a further extended area into a storage angle having a plurality of recording areas adjacent to each other to a limitable angle of incidence; Injecting the reference light by changing an incident angle to an angle within the threshold angle range when the angle reaches the threshold angle or more; Detecting adjacent reproduced light reproduced in a recording area adjacent to the selected recording area; And And controlling the reproduction condition of the selected reproduction light reproduced in the selected recording area by using the optical information of the adjacent reproduction light, and detecting the selection reproduction light. 7. The method of claim 6, wherein the reproduction condition is any one of an incident angle of the reference light and a tilting state of the optical information storage medium. 7. The optical information reproducing method according to claim 6, wherein the recording areas form a plurality of tracks having different diameters, and the reference light is incident at multiplexing angles having different offset angles for each track. 10. The optical information reproducing method according to claim 8, wherein the detection of the selected reproduction light is performed on the remaining tracks except the innermost track and the outermost track of the storage medium. The optical information reproducing method according to claim 8, wherein the multiplexing angle having the offset angle is incident while changing from a small angle to a large angle. The optical information reproducing method according to claim 6, wherein when the angle of the angle greater than or equal to the limit angle is changed within a range, the incident light is changed while changing from a large angle to a small angle. 7. The optical information reproducing method according to claim 6, wherein the optical information of the adjacent reproduction light is an amount of light. Injecting a reference light having a further extended area into an optical information storage medium having a plurality of recording areas adjacent to each other, to a limitable angle of incidence; Injecting the reference light by changing an incident angle to an angle within the threshold angle range when the angle reaches the threshold angle or more; Detecting adjacent reproduced light reproduced in a recording area adjacent to the selected recording area; And And controlling the reproduction condition of the selected reproduction light to be reproduced in the selected recording area by comparing the optical information of the adjacent reproduction light beams. The method of claim 13, wherein the reproduction condition is one of an incident angle of the reference light and a tilting state of the optical information storage medium.

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