KR100846573B1 - Optical information processing apparatus and optical information processing method - Google Patents

Abstract

The present invention relates to an optical information processing apparatus and an optical information processing method, and the optical information processing apparatus and the optical information processing method according to the present invention multi-record optical information at a plurality of angles in one recording area, Multiple overlapping recording areas partially overlapped with the recording area are multi-recorded at different angles so that the null height of diffraction energy reproduced in each of the recording area and the partially overlapping recording area is lowered, thereby causing crosstalk during recording and reproduction of optical information. There is an effect of reducing crosstalk noise and improving optical information recording quality and reproduction efficiency.

Description

Optical information processing apparatus and optical information processing method

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

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

3A and 3B are conceptual views illustrating an angle multiplexing state between reference light and signal light according to an exemplary embodiment of the present invention.

FIG. 4A is a view showing incident regions of reference light and signal light with respect to the first recording area in the optical information processing method according to the embodiment of the present invention.

4B is a diagram for explaining a first recording area in the optical information processing method according to the embodiment of the present invention.

FIG. 5A illustrates an incident region of a reference light and a signal light with respect to a second recording area in the optical information processing method according to the embodiment of the present invention.

5B is a diagram for explaining a second recording area in the optical information processing method according to the embodiment of the present invention.

FIG. 6A illustrates an incident region of reference light and signal light with respect to the first partial overlapping recording area in the optical information processing method according to the embodiment of the present invention.

6B is a diagram for explaining a first partial overlapping recording area in the optical information processing method according to the embodiment of the present invention.

 FIG. 7A illustrates an incident region of the reference light and the signal light with respect to the second partial overlapping recording area in the optical information processing method according to the embodiment of the present invention.

7B is a diagram for explaining a second partial overlapping recording area in the optical information processing method according to the embodiment of the present invention.

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

9A, 9B, 9C and 9D are graphs showing the diffraction energy in each area after optical information is recorded in the recording area and the partially overlapped recording area by angular multiplexing in the first incident angle range.

10A, 10B, 10C, and 10D show optical information in a recording area by angular multiplexing in a first incident angle range, and optical information in a partially overlapped recording area by angular multiplexing in a second incident angle range, respectively. This graph shows the measurement of diffraction energy in the region of.

The present invention relates to an optical information processing apparatus and an optical information processing method, and more particularly, to an optical information processing apparatus and an optical information processing method for processing optical information using two or more types of multiple recording methods.

One of the optical data processing apparatuses, the holographic optical information processing apparatus, is such that an interference fringe formed by intersecting two lights in a storage medium is recorded on the storage medium. This interference fringe can be said to be data for recording. One of the two lights is an optical modulated signal beam, and the other is a reference beam having the same wavelength. The holographic optical information processing apparatus irradiates only the reference light to the interference fringe formed on the storage medium, and detects a readout beam that is diffracted and reproduced from the interference fringe to reproduce the data.

The holographic optical information processing apparatus also uses various kinds of multiplexing methods to increase the recording capacity.

Multiplexing methods include angular multiplexing, phase-code multiplexing, wavelength multiplexing, and shift multiplexing. Peristrophic multiplexing, correlation multiplexing, and fractal multiplexing.

There are also techniques for applying two or more of these multiplexing methods in combination. Among the techniques of applying a plurality of multiplexing methods is a polytopic multiplexing method.

Polytopic multiplexing is disclosed in the US Pat. No. 7,092,133, proposed by Kenneth et al. Under the name “Polytopic multiplex holography”, and Optics letters, Volume 29, Issue 12, pp. Anderson, Ken, at 1402-1404 (June 2004); It is disclosed by Curtis, Kevin under the name "Polytopic multiplexing".

Polytopic multiplexing proposed by Kenneth et al. Records optical information by partial spatial overlapping of adjacent hologram stacks of a storage medium. Each hologram stack discloses that optical information can be multiplexed by any one of angle, wavelength, phase code, peristrophic, correlation, or fractal multiplexing.

On the other hand, holograms superimposed and recorded by the multiplexing method may reduce the reproduction efficiency of optical information if the diffraction efficiency is not uniform. Therefore, it is also important that the holograms recorded by the multiplexing method in the storage medium have good diffraction efficiency and uniformity in their reproduction. However, most of the proposed multiplexing methods for recording multiple holograms in the related art only provide a proposal for increasing the recording density, and do not consider the diffraction efficiency of the hologram during reproduction.

An object of the present invention is to provide an optical information processing apparatus and an optical information processing method for superimposing and recording optical information on a storage medium by a plurality of multiplexing methods to improve the recording density of optical information.

An optical information processing apparatus according to the present invention includes an optical modulator for modulating light traveling to a storage medium into signal light, a reference light optical system for inputting reference light to the storage medium by a path different from the signal light, and the signal light incident on the storage medium and the An incident angle controller for adjusting the incident angle of the reference light is provided.

The incident angle controller may be a rotary actuator for rotating the storage medium. The storage medium may be supported by a linear actuator that linearly moves the incident positions of the signal light and the reference light. The incidence angle adjuster may allow each of the signal lights to be incident at different incidence angles when the signal light and the reference light are incident multiple times in one recording area.

The incidence angle adjuster is a second incidence angle that is different from the first incidence angle range used in forming the recording area when forming the overlapping recording area partially overlapping the recording area after the recording area is formed on the storage medium. The signal light and the reference light may be incident in a range of degrees.

An optical information processing apparatus according to the present invention includes an optical modulator for modulating light traveling to a storage medium into signal light, a reference light optical system for inputting reference light to the storage medium by a path different from the signal light, and when the signal light is repeatedly incident at one position. The reference light is incident on the first incident angle range, and when the signal light is incident on a position partially overlapping the recording area after the recording area is formed on the storage medium, the reference light is different from the first incident angle range. And an incident angle controller for allowing the reference light to be incident in a range of two incident angles. The incident angle controller may be a rotating mirror that reflects the reference light to adjust the incident angle.

The optical information processing apparatus according to the present invention is incident on the recording area of the storage medium by changing the reference light in the first incident angle range and the first incident angle to the partially overlapped recording area partially overlapping the recording area of the storage medium. And a reference light incident optical system in which the reference light is changed at an angle in a second incident angle range, which is another angle, and a reproduction light detector for detecting the reproduction light reproduced from the storage medium.

The reference light incident optical system may include a rotatable mirror that adjusts an incident angle of the reference light. A filter may be provided between the reference light incident optical system and the reproduction light detector.

In the optical information processing method according to the present invention, the first signal light is incident on the storage medium, and the first reference light, which is adjusted in the first incident angle range together with the first signal light, is incident at a position where the first signal light of the storage medium is incident. A second reference light controlled to form a recording area, the second signal light partially overlapping the recording area, and adjusted together with the second signal light in a second incident angle range that is different from the first incident angle range. A partial overlapping recording area is formed at the position where the second signal light is incident on the storage medium.

The first signal light may be adjusted together with the first reference light within the first incident angle range. The second signal light may be adjusted together with the second reference light within the second incident angle range. The recording area may include a first recording area spaced apart from each other and a second recording area formed between the first recording areas. The first reference lights incident to form the first recording area may not have incident areas overlapping each other. Incident regions of the first reference lights incident to form the second recording region may not overlap each other. The first recording area and the second recording area may not overlap each other. The partial overlapping recording area may overlap both sides of the first recording area and the second recording area.

The partial overlapping recording area may include a first partial overlapping recording area formed after the recording area is formed and spaced apart from each other, and a second partial overlapping recording area formed between the first partial overlapping recording area.

The second reference lights incident to form the first partial overlapping recording area may not overlap the incident areas. Incident regions of the second reference lights incident to form the second partial overlapping recording region may not overlap each other. The first partial overlapping recording area and the second partial overlapping recording area may not overlap each other.

In the optical information processing method according to the present invention, light is incident and superimposed on the recording area at an angle of a first incidence range having a plurality of angle units, and has a plurality of angle units different from the first incidence range. A reference light is incident on the recording area at an angle of the first incidence range to reproduce the optical information from the recording area on a storage medium in which light is incident at an angle of two incidence ranges and partially overlapped with the recording area. The reference light is incident and detected at an angle of the second incidence range to reproduce the optical information from the partially overlapped recording area.

After the reproducing of the recording area, the partial overlapping recording area can be reproduced.

After the partial overlapping recording area is reproduced, the recording area can be reproduced.

The recording area includes a first recording area formed spaced apart from each other and a second recording area formed between the first recording areas, and the first reference light incident on the first recording area does not overlap the incidence areas. Can be.

The recording area includes a first recording area spaced apart from each other and a second recording area formed between the first recording areas, and the first reference light incident on the second recording area does not overlap the incident areas. Can be.

The partial overlapping recording area includes a first partial overlapping recording area formed between the first partial overlapping recording area and the first partial overlapping recording area formed after the recording area is formed, and the first partial overlapping recording area. The second reference lights incident on the second incident light may not overlap each other.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a block 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 embodiment of the present invention includes a light source 10, a polarizer beam splitter 20, an optical system for signal beam 40, and a reference light optical system. an optical system for reference beam (30) and a storage medium stage (60).

The light source 10 may employ a blue light laser having a wavelength between 450 nm and 500 nm, a green light laser having a wavelength between 500 nm and 570 nm, or another kind of light. The polarization beam splitter 20 splits the light incident from the light source 10 according to the polarization direction. The polarization beam splitter 20 transmits P-polarized light and reflects S-polarized light. P-polarized light proceeds to the signal light optical system 40 and S-polarized light proceeds to the reference light optical system 30.

The reference light optical system 30 includes a reflection mirror 31 that reflects the light reflected from the polarization beam splitter 20 to the storage medium 50. The reflection mirror 31 may be implemented as a rotating mirror to function as an incident angle adjuster. And in the case of a rotating mirror can be used Galvano mirror (Galvano mirror). The rotating mirror may enter the storage medium 50 by adjusting the reference light R at a plurality of incident angles. That is, the rotating mirror may perform angular multiplexing of the reference light R.

The signal optical system 40 includes a spatial filter 41 for removing noise components of the light reflected from the polarization beam splitter 20, and a collimating lens for advancing the light passed through the spatial filter 41 into parallel light. 42).

In addition, the signal light optical system 40 includes a reflection mirror 43 and an optical modulator 44 positioned after the collimating lens 42, a pair of focus lenses 45, and an aperture located between the focus lenses 45. an aperture 46 and a fourier transform lens 47.

The light modulator 44 may use a transmissive spatial light modulator such as a liquid crystal (LC). In another embodiment, the optical modulator 44 may use a reflective spatial light modulator such as a digital micro-mirror device (DMD). The optical modulator 44 modulates data recorded on the storage medium 50 into digital data. Therefore, when light enters the optical modulator 44, the light is loaded with data for recording. The light loaded with data proceeds to the storage medium 50 as the signal light S.

The storage medium stage 60 supports the storage medium 50 on which optical information is recorded. The linear actuator 70 is connected to the storage medium stage 60 to linearly move the storage medium 50. In addition, a rotating actuator 80 may be connected to the storage medium stage 60. The rotary actuator 80 may function as an incident angle adjuster for angular multiplexing the reference light R and the signal light S at the same time.

The rotary actuator 80 may be configured to rotate the storage medium stage 60 and the linear actuator 70 together, or the linear actuator 70 may move the storage medium stage 60 and the rotary actuator 80 together. It can be configured to move linearly together.

On the other hand, the optical information processing apparatus according to an embodiment of the present invention may include an optical system for readout beam (90) for reproducing the optical information recorded on the storage medium (50). The reproduction light optical system 90 includes a filter 91, an inverse fourier transform lens 92, and an optical filter 91 installed at opposite positions to which the signal light S and the reference light R are incident on the storage medium 50. An information detector 93 is provided.

The optical information detector 93 may use a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The reproduction light optical system 90 may not be provided when the optical information processing apparatus is implemented for recording only. On the other hand, when the optical information processing apparatus is implemented only for reproduction, the signal optical system 40 may not be provided.

In the above-described embodiment, when the reflection mirror 31 of the reference light optical system 30 is a rotating mirror to angularly multiplex only the reference light R, the storage medium stage 60 does not rotate or the rotation actuator 80 is rotated. In this case, when the reference light S and the signal light R are angularly multiplexed together, the reflective mirror 31 may be fixed.

Hereinafter, an optical information processing method according to an embodiment of the present invention using the optical information processing device having the above-described configuration will be described.

2 is a flowchart illustrating an optical information processing method according to an embodiment of the present invention. As shown in FIG. 2, in the optical information processing method according to an exemplary embodiment, the first signal light S1 and the first reference light R1 controlled in the first incident angle range are incident and recorded on the storage medium 50. In step S10, the region 100 is formed. In this case, the recording area 100 is formed so that a plurality of recording areas 100 do not overlap each other in different areas of the storage medium 50.

In addition, the recording area 100 may be sequentially formed at positions adjacent to each other along the linear movement direction of the storage medium 50, or may be partially formed to be spaced apart from each other, and then formed between the already formed recording areas 100. FIG. Other recording areas 100 can be formed secondly without overlapping the recorded recording area 100. When the recording area 100 is formed, the first signal light S1 may be adjusted together with the first reference light R1 in the first incident angle range.

When the recording area 100 is formed, the second signal light S2 and the second reference light R2 are incident to partially overlap the recording areas 100 between the recording areas 100 so as to partially overlap the recording area 110. Step S11 is performed. In this case, the first reference light R2 is adjusted in the second incident angle range, which is different from the first incident angle. The second signal light S2 may also be adjusted together with the second reference light R2 in the second incident angle range.

On the other hand, when only the first reference light (R2) and the second reference light (R2) is adjusted in the angle can be carried out using a mirror reflecting the reference light (R) as a rotating mirror, the first reference light (R1) and the second When the reference light R2 is angled together with the first signal light S1 and the second signal light S2, respectively, the reference light R2 may be implemented by rotating the storage medium stage 60 with the rotary actuator 80.

3A and 3B are conceptual views illustrating a recording method according to an embodiment of the present invention for the case of angular multiplexing the reference light and the signal light according to the embodiment of the present invention. As shown in FIG. 3A, the storage medium 50 is rotated within the first incident angle range to form the recording areas 100 that do not overlap each other in the storage medium 50. As a result, the first reference light R1 and the first signal light S1 are incident on the storage medium 50 at multiple angles. The angle ?? between the first reference light R1 and the first signal light S1 is kept the same.

In addition, as shown in FIG. 3B, storage is performed within a second incident angle range different from the first incident angle range to form a partially overlapped recording region 110 partially overlapping the recording region already recorded on the storage medium 50. Rotate the medium 50. In this rotation, the second reference light R2 and the second signal light S2 are incident on the storage medium 50 at multiple angles within a second incident angle range. In this case, the angle ?? between the second reference light R2 and the second signal light S2 is kept the same.

That is, when the recording area 100 is formed in the storage medium 50 without overlapping with each other, the first reference light R1 and the first signal light S1 are multiplexed in the range of the first incident angle, and then the recording is performed. When the partial overlapping recording area 110 is partially overlapped in the area 100, the second reference light R2 and the second signal light S2 are multiplexed in the range of the second incident angle.

Hereinafter, the embodiment of the recording method of the recording area and the partially overlapped recording area will be described in more detail. In the embodiment of the present invention, the recording area 100 may be divided into a first recording area 101 and a second recording area 102.

First, a recording method for the first recording area 101 will be described. FIG. 4A illustrates an incident region of a reference light and a signal light with respect to a first recording area of an optical information processing method according to an embodiment of the present invention, and FIG. 4B illustrates an optical information processing method according to an embodiment of the present invention. It is a figure for explaining a 1st recording area.

As shown in FIG. 4A, the first signal light S1 is incident on the first recording area 101. As shown in FIG. The first reference light R1 is incident to a size larger than the incident size of the first signal light S1. Therefore, the first recording area 101 is formed in the area of the storage medium 50 where the first signal light S1 and the first reference light R1 interfere with each other. The storage medium 50 is rotated at a plurality of angles within the first incident angle range set for the first recording area 101. Each time the storage medium 50 rotates at each angle, the first signal light S1 is incident to the first recording area 101 together with the first reference light R1 having different data from the previous recording. Causes overlap to be recorded. That is, a plurality of superposed optical information is recorded in one first recording area 101 by the angle multiplexing method.

Thereafter, the storage medium 50 is moved by a predetermined distance using the linear actuator 70 to form another first recording area 101. When the storage medium 50 is moved to a position for forming another first recording area 101 'by a predetermined distance, the first signal light S1 having different information is incident to record the optical information.

At this time, rotation of the storage medium 50 to form another first recording area 101 'is performed by rotating the storage medium 50 to form the previous first recording area 101 in the range of the first incident angle. The recording medium may be rotated in the opposite direction, or the storage medium 50 may be rotated to form the first first recording area 101 in the first incident angle range after the storage medium 50 is returned to the set initial angle. Recording can be performed while rotating in the same direction.

The predetermined distance between the previous first recording area 101 and the subsequent first recording area 101 'may be such that the respective first reference lights R1 are in contact with each other and do not overlap each other. Thereafter, the storage medium 50 is linearly moved to form the first recording areas 101 and 101 ′ on the entire storage medium 50. In this manner, as shown in FIG. 4B, the first recording areas 101 and 101 ′ are recorded in a state in which they are spaced apart from each other by a predetermined distance.

Next, a recording method for the second recording area 102 will be described. FIG. 5A illustrates an incident region of a reference light and a signal light with respect to a second recording area of the optical information processing method according to an embodiment of the present invention, and FIG. 5B illustrates an optical information processing method according to an embodiment of the present invention. This is a figure for explaining the second recording area.

This second recording area 102 refers to an area recorded between the first recording areas 101 and 101 '. The second recording area 102 is an area which does not overlap the first recording areas 101 and 101 '.

As shown in FIG. 5A, the first signal light S1 having the corresponding information is incident at a position for forming the second recording area 102. The position with respect to the second recording area 102 is secured by linearly moving the storage medium 50. The first reference light R1 is incident to a size larger than the incident size of the first signal light S1. Therefore, the second recording area 102 is formed in the area of the storage medium 50 where the first signal light S1 and the second reference light R2 interfere with each other. In this case, since the incident region of the first reference light R1 is larger than the incident region of the first signal light S1, it may partially overlap the first recording region 101.

Then, the storage medium 50 is rotated with respect to the second recording area 102 at a plurality of angles within the same first incident angle range as the range used for recording the first recording area 101. Each time the storage medium 50 rotates at each angle, the first signal light S1 is incident to the second recording area 102 together with the first reference light R1 having different data from the previous recording. Are written to overlap. That is, a plurality of superposed optical information is recorded in one second recording area 102 by an angular multiplexing method.

Thereafter, the storage medium 50 is moved by a predetermined distance using the linear actuator 70 to form another second recording area 102 '. When the storage medium 50 is moved to a position for forming another second recording area 102 ', another second recording area 102' is formed.

Meanwhile, the predetermined distance between the previous second recording area 102 and the subsequent second recording area 102 'may be such that the respective first reference lights R1 are in contact with each other and do not overlap each other. Thereafter, the storage medium 50 is linearly moved to form the second recording areas 102 and 102 ′ in the corresponding portions of the storage medium 50. In this manner, as shown in FIG. 5B, the second recording areas 102 and 102 ′ are recorded with a predetermined distance from each other. Accordingly, the recording shape of each recording area 100 is a form in which a pair of the first recording area 101 and the second recording area 102 are sequentially formed repeatedly.

Thereafter, the partial overlapping recording area 110 is formed. In an embodiment of the present invention, the partial overlapping recording area 110 may be divided into a first partial overlapping recording area 111 and a second partial overlapping recording area 112.

First, a recording method for the first partial overlapping recording area 111 will be described. FIG. 6A illustrates an incidence region of a second reference light and a second signal light with respect to a first partial overlapping recording area in an optical information processing method according to an embodiment of the present invention, and FIG. 6B is an embodiment of the present invention. It is a diagram for explaining a first partial overlapping recording area for the optical information processing method.

As shown in FIG. 6A, the second signal light S2 is incident on the first partial overlapping recording area 111. The first partial overlapping recording area 111 at this time is between the first recording area 101 and the second recording area 102 which are in contact with each other. Accordingly, the first partial overlapping recording area 111 is partially overlapped with the first recording area 101 and the right part is partially overlapped with the second recording area 102.

The second reference light R2 is incident to a size larger than the incident size of the second signal light S2. Accordingly, the first partial overlapping recording area 111 is formed in the area of the storage medium 50 where the second signal light S2 and the second reference light R2 interfere with each other. The storage medium 50 is rotated at a plurality of angles within the second incident angle range set for the first partial overlapping recording area 111. Here, the second incident angle range is an angle range different from the first incident angle range. For example, when the first incident angle range is 0 to 14.7 °, the second incident angle range may be 16 to 34.7 °.

Each time the storage medium 50 rotates at each angle in the second incident angle range, the first partial overlaps with the second reference light R2 and enters the second signal light S2 having different data from the previous recording. Optical information is superimposed on the recording area 111 to be recorded. In this case, each angle of rotating the storage medium 50 for angle multiplexing may be, for example, 0.21 °. Therefore, a plurality of superposed optical information is recorded in one first overlapping recording area 111 by the angle multiplexing method.

Thereafter, the storage medium 50 is moved by a predetermined distance using the linear actuator 70 to form another first overlapping recording area 111 '. When the storage medium 50 is moved to a position for forming another first overlapping recording area 111 ', optical information is recorded in the same manner as the recording method of the first first overlapping recording area 111. FIG.

The rotation of the storage medium 50 for multiple recordings in the other first overlapping recording area 111 'is performed to form the previous first overlapping recording area 111 in the range of the second incident angle. Recording 50 by rotating in the opposite direction of rotation, or forming the first first overlapping recording area 111 in the second incident angle range after returning the storage medium 50 to the set initial angle. For this purpose, the recording medium 50 can be recorded while rotating in the same direction in which the storage medium 50 is rotated.

The predetermined distance between the first partial overlapping recording area 111 and the subsequent first partial overlapping recording area 111 'is such that the portion where the second reference lights R2 are incident is in contact with each other and does not overlap each other. can do. Thereafter, the storage medium 50 is linearly moved to form first partial overlapping recording areas 111 and 111 ′ in the corresponding area of the storage medium 50. In this manner, as shown in FIG. 6B, the first partial overlapping recording areas 111 and 111 ′ are recorded with a predetermined distance from each other.

Next, a recording method for the second partial overlapping recording area 112 will be described. FIG. 7A illustrates an incident region of reference light and signal light for a second partial overlapping recording area in the optical information processing method according to an embodiment of the present invention, and FIG. 7B is an optical information processing method according to an embodiment of the present invention. Is a diagram for explaining a second partial overlapping recording area.

The second partial overlapping recording area 112 refers to an area between the first partial overlapping recording areas 111 and the first partial overlapping recording area 111. The second partial overlapping recording area 112 is an area which does not overlap the first partial overlapping recording area 111.

As shown in FIG. 7A, the second signal light S2 is incident on the second partial overlapping recording area 112. The position with respect to the second partial overlapping recording area 112 is secured by linearly moving the storage medium 50. The second reference light R2 is incident to a size larger than the incident size of the second signal light S2. Accordingly, the second partial overlapping recording area 112 is formed in the area of the storage medium 50 where the second signal light S2 and the second reference light R2 interfere with each other. At this time, since the incident region of the second reference light R2 is larger than the incident region of the second signal light S2, it partially overlaps with the first partial overlapping recording region 111.

Then, the storage medium 50 is rotated with respect to the second partial overlapping recording area 112 at a plurality of angles within the same second incident angle range as that used for recording the first partial overlapping recording area 111. Each time the storage medium 50 rotates at each angle, a second signal light S2 having different data from the previous recording is incident together with the second reference light R2 to enter the second overlapping recording area 112. Light information is superimposed and recorded. Therefore, a plurality of superposed optical information is recorded in the second partial overlapping recording area 112 by the angle multiplexing method.

Thereafter, the storage medium 50 is moved by a predetermined distance using the linear actuator 70 to form another second overlapping recording area. When the storage medium 50 is moved to a position for forming another second overlapping recording area, optical information is recorded in the same manner as the recording method of the previous second overlapping recording area 112.

The predetermined distance between the previous second partial overlapping recording area 112 and the subsequent second partial overlapping recording area 112 may be such that the respective second reference lights R2 are in contact with each other and do not overlap each other. . Thereafter, the storage medium 50 is linearly moved to form another second overlapping recording area in the corresponding area of the storage medium 50. In this manner, as shown in FIG. 7B, the second partial overlapping recording areas 112 are recorded at a distance from each other by a predetermined distance. Accordingly, the recording shape of each recording area is such that a pair of the first partial overlapping recording area 111 and the second partial overlapping recording area 112 are sequentially formed repeatedly.

Hereinafter, a method of reproducing optical information from an optical information storage medium in which optical information is recorded by the above-described method will be described.

8 is a block flowchart illustrating an optical information processing method for reproducing optical information according to an embodiment of the present invention. As shown in FIG. 8, in the optical information reproducing method, only the reference light R1 and R2 are incident on the storage medium 50, and the reproduction information reproduced in each recording area of the storage medium 50 is detected by the optical information detector 93. ) Is detected.

At this time, the incident first reference light R1 is incident on the first recording area 101 and the second recording area 102 while the angle is changed in the range of the first incident angle (S20), and the second reference light R2 is applied. Is incident on the first partial overlapping recording area 111 and the second partial overlapping recording area 112 while the angle is changed in the range of the second incident angle (S21). The angle of incidence of the reference lights R1 and R2 may be changed by the rotating mirror or the rotating actuator 80, and the linear movement of each storage medium 50 may be performed by the linear actuator 70.

The reproduction order of the recording area 100 and the partial overlapping recording area 110 may be to reproduce the recording area 100 first, and then to reproduce the partial overlapping recording area 110, or the partial overlapping recording area 110 may be reproduced. After the first playback, the recording area 100 can be played back. Also in the case of the recording area 100, the second recording area 102 can be reproduced after the first recording area 101 is reproduced or vice versa. Also, in the case of the partial overlapping recording area 110, the second partial overlapping recording area 112 can be reproduced after the first partial overlapping recording area 111 is reproduced, or vice versa. Or in any other order.

The optical information processing method according to the embodiment of the present invention has a range of the first incident angle used when the recording area 100 is formed and a second incident angle used when the partial overlapping recording area 110 is formed. The range is different. When the angular range is changed in this way, the recording quality can be improved when the respective recording areas 100 or the partial overlapping recording areas 110 are formed.

Hereinafter, an experimental example according to the optical information processing device and the optical information processing method as described above will be described.

9A, 9B, 9C, and 9D show optical information in the recording area 100 and the overlapping recording area 110 by angular multiplexing in the first incident angle range, and then measure diffraction energy in each area. The graph shown.

In the present experimental example, the range of the first incident angle was 0 to 14.7 °, and each change angle was 0.21 °. Therefore, 71 holograms were superimposed on each of the recording area 100 or the partial overlapping recording area 110.

In this case, when the diffraction energy of each recording area 100 and the partial overlapping recording area 110 is measured, the height of the null with respect to the diffraction energy of the first recording area 101 shown in FIG. The height of the null for the diffraction energy in the second recording region 102 shown in FIG. 9B and the height of the null for the diffraction energy of the first partial overlapping recording region 111 shown in FIG. 9C and shown in FIG. 9D. The height of the null with respect to the diffraction energy of the second partial overlapping recording area 112 is shown to be higher.

That is, in the case of the second recording area 102 and the second partial overlapping recording area 112, the heights of the nulls were higher than the null heights of the first recording area 101 and the first partial overlapping recording area 111 as a whole. . The cause for this is not known theoretically. However, since the null diffraction energy value acts as noise at the time of reproduction of the optical information, in conclusion, a large null energy indicates that the noise is so large that it causes a decrease in the quality of the reproduction data.

An example of experimenting with the optical information processing apparatus and the optical information processing method according to the embodiment of the present invention to be compared to this will be described.

10A, 10B, 10C, and 10D perform optical information recording on a recording area by angular multiplexing in the first incident angle range, and angle multiplexing having a different range from the first incident angle range in the overlapping recording area. After recording optical information, the graph shows the measured diffraction efficiency in each area.

In this Experimental Example, the angle of incidence of the first incident angle was 0 to 14.7 ° for angle multiplexing with respect to the first recording area 101 and the second recording area 102. The first partial overlapping recording area 111 and the The range of the second incident angle with respect to the two-part overlapping recording area 112 was in the range of 16 to 34.7 degrees. The change angle in each incident range was 0.21 °. That is, 71 holograms were overlaid on each recording area 100 or partial overlapping recording area 110.

In this case, the diffraction efficiency of each recording area 100 and the partial overlapping recording area 110 is measured. As shown in FIGS. 10A, 10B, 10C, and 10D, the diffraction energy of all recording areas is measured. It can be seen that the null position appears quite similar. That is, in the case of FIG. 10C compared to FIG. 9C and the case of FIG. 10D compared to FIG. 9D, the height of the null with respect to the diffraction energy of the second recording region 102 and the second partial overlapping recording region 112 is lowered. can see.

These experimental results indicate that as the height of the null is lowered, crosstalk noise in the overlapping recording areas is reduced. When the crosstalk noise is reduced, the quality of the recorded hologram is improved, and the reproduction efficiency is improved even when the data is reproduced.

In the optical information processing apparatus and the optical information processing method according to the embodiment of the present invention as described above, various modified embodiments may be implemented within the scope of the technical idea of the present invention. For example, the type of light source, the adoption of a selective angle multiplexing method of the reference light and the signal light, or the implementation as a recording-only device or a reproduction-only device as part of the configuration of the embodiment, an apparatus for processing optical information by rotating a storage medium or the like. By using the optical information processing device of another configuration of the optical information recording and reproducing method according to the spirit of the present invention it may be possible.

The optical information processing apparatus and the optical information processing method according to the embodiment of the present invention as described above include incidence angle ranges of the reference light or the signal light adjusted for angular multiplexing in the superimposed recording areas in the recording area and the recording area. By differing in the overlapping partial overlapping recording areas, the null height of the diffraction energy in each of the recording areas can be lowered, thereby reducing crosstalk noise during recording and reproduction of the optical information. There is an effect to improve recording quality and reproduction efficiency.

Claims (28)

An optical modulator for modulating the light traveling to the storage medium into signal light; A reference light optical system for inputting reference light to the storage medium by a path different from the signal light; And an incidence angle adjuster for adjusting incidence angles of the signal light and the reference light incident on the storage medium. The optical information processing apparatus according to claim 1, wherein the incident angle adjuster is a rotary actuator for angularly rotating the storage medium. The optical information processing apparatus according to claim 1, wherein the storage medium is supported by a linear actuator for linearly moving the incident positions of the signal light and the reference light. 4. The optical information processing apparatus according to claim 3, wherein the incidence angle controller causes each of the signal lights to be incident at different incidence angles when the signal light and the reference light are incident multiple times in one recording area. 4. The method of claim 3, wherein the incidence angle adjuster comprises: a first incidence angle range used in forming the recording area when forming a partially overlapped recording area partially overlapping the recording area after the recording area is formed on the storage medium; And the signal light and the reference light are incident at different second incident angle ranges. An optical modulator for modulating the light traveling to the storage medium into signal light; A reference light optical system for inputting reference light to the storage medium by a path different from the signal light; When the signal light is repeatedly incident at one position, each of the reference lights is incident at a first incident angle range, and when the signal light is incident at a position partially overlapping the recording area after the recording area is formed on the storage medium, And an incident angle adjuster for causing the reference light to enter the second incident angle range which is an angle different from the first incident angle range. The optical information processing apparatus according to claim 6, wherein the incident angle controller is a rotating mirror which reflects the reference light to adjust the incident angle. A second incident angle that is different from the first incident angle range in a partially overlapped recording region partially overlapped with the recording region of the storage medium, and is incident by changing the reference light in a first incident angle range into the recording region of the storage medium; A reference light incident optical system in which the reference light is angled and changed in the range; And a reproducing light detector for detecting reproducing light reproduced in said storage medium. The optical information processing apparatus according to claim 8, wherein the reference light incident optical system includes a rotating mirror that adjusts an angle of incidence of the reference light. The optical information processing apparatus according to claim 8, wherein a filter is provided between the reference light incident optical system and the reproduction light detector. The first signal light is incident on the storage medium, A first reference light, which is controlled in a first incident angle range together with a first signal light, is incident at a position where the first signal light of the storage medium is incident to form a recording area. Incident the second signal light to partially overlap the recording area, And a second reference light controlled at a second incident angle range that is different from the first incident angle range together with the second signal light at a position where the second signal light of the storage medium is incident to form a partially overlapped recording area. Optical information processing method characterized in that. 12. The optical information processing method according to claim 11, wherein the first signal light is adjusted together with the first reference light in the first incident angle range. 12. The optical information processing method according to claim 11, wherein the second signal light is adjusted together with the second reference light in the second incident angle range. 14. The optical information processing method according to claim 13, wherein the recording area includes a first recording area which is formed spaced apart from each other, and a second recording area which is formed between the first recording areas. 15. The optical information processing method according to claim 14, wherein the first reference lights incident to form the first recording area do not overlap the incident areas. The optical information processing method according to claim 14, wherein the incidence regions of the first reference lights incident to form the second recording region do not overlap each other. 15. The optical information processing method according to claim 14, wherein the first recording area and the second recording area do not overlap each other. 15. The optical information processing method according to claim 14, wherein the partial overlapping recording area overlaps both sides of the first recording area and the second recording area. 19. The apparatus of claim 18, wherein the partial overlapping recording area includes a first partial overlapping recording area formed between the first partial overlapping recording area and a first partial overlapping recording area spaced apart from each other after the recording area is formed. Optical information processing method characterized in that. 20. The optical information processing method according to claim 19, wherein the second reference lights incident to form the first partial overlapping recording area do not overlap the incident areas. 20. The optical information processing method according to claim 19, wherein incidence regions of the second reference lights incident to form the second partial overlapping recording region do not overlap each other. 20. The optical information processing method according to claim 19, wherein the first partial overlapping recording area and the second partial overlapping recording area do not overlap each other. The light is incident on the recording area at an angle of the first incident range having a plurality of angle units and superimposed thereon, and the light is incident at an angle of a second incident range having a plurality of angle units different from the first incident range. A reference light is incident on the recording area at an angle of the first incidence range to reproduce the optical information from the recording area on a recording medium which is partially superimposed on the recording area and reproduces the optical information from the partial overlapping recording area. And the reference light is incident and detected at an angle of the second incident range. 24. The optical information processing method according to claim 23, wherein the partial overlapping recording area is reproduced after the recording area is reproduced. 24. The optical information processing method according to claim 23, wherein the recording area is reproduced after the partial overlapping recording area is reproduced. 24. The recording medium of claim 23, wherein the recording area comprises a first recording area spaced apart from each other and a second recording area formed between the first recording areas, wherein the first reference light incident on the first recording area is incident. Optical information processing method characterized in that the areas do not overlap each other. 24. The recording medium of claim 23, wherein the recording area includes a first recording area spaced apart from each other and a second recording area formed between the first recording areas, and the first reference light incident on the second recording area is incident. Optical information processing method characterized in that the areas do not overlap each other. 24. The apparatus of claim 23, wherein the partial overlapping recording area includes a first partial overlapping recording area formed between the first partial overlapping recording area and a first partial overlapping recording area spaced apart from each other after the recording area is formed. And the second reference lights incident on the first partial overlapping recording area do not overlap the incident areas.

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