KR100681614B1 - Method for recording and playing in holographic storage system - Google Patents

Abstract

In the present invention, a holographic data storage system of a coupon type, holographic data recorded using each multiplexing method and recorded using the property of total reflection at an interface when light enters at an angle greater than or equal to a critical angle at an interface with different refractive indices In the recording process, the protective layer for protecting the holographic storage material is positioned above / below the holographic storage material, and the mask is placed on the upper protective layer. The process 31 to allow signal light to be irradiated in the process, the process 32 to allow the reference light to enter at an arbitrary angle on the lower left side of the lower protective layer, and the hologram data generated by the interference between the signal light and the reference light. And the thirty-third step of writing to the storage material. Then, the regeneration process for this, the protective layer for protecting the holographic storage material is positioned above and below the holographic storage material, the incident angle of the reference light at the time of recording in a state that the CCD is positioned on the upper protective layer Step 81 of irradiating reference light from the lower left critical surface of the lower protective layer at the same angle as that of step 82; reproducing hologram data recorded on the holographic storage material by the irradiated reference light; And detecting the hologram data using a CCD. Therefore, the production process using one device is possible, so mass production is possible, and when the holographic data is reproduced from the produced holographic disc, the unit can be reproduced with a simple device, thereby lowering the unit cost of the disc and also reproducing. The cost of the device can be lowered, thereby reducing the economic burden.

Description

Recording and playback method in holographic storage system {METHOD FOR RECORDING AND PLAYING IN HOLOGRAPHIC STORAGE SYSTEM}

1 is a diagram schematically illustrating a holographic storage system using a conventional total reflection layer,

2 is a diagram for a reproducing method in a holographic storage device using a conventional total reflection layer;

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Figure 3 is a view of producing a holographic storage material according to the present invention,

4 is a diagram for the law of refraction,

5 is a diagram for a recording method in a holographic storage system according to the present invention;

FIG. 6 is a top view illustrating a plurality of coupon type pattern masks in the entire mask shown in FIG. 5;

FIG. 7 is a diagram illustrating a method for reproducing holographic data recorded in the holographic storage material by FIGS. 5 and 6;

FIG. 8 is a diagram for recording and reproducing hologram data by directly using an array of small holographic storage materials to correspond to a mask according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10, 30: protective layer 20: hologram storage material

40: mask 50: CCD

SS1: reference light SS2: signal light

SS3: reproduction signal light SS4: hologram data
SS5: reference light larger than the size of the light of the reference light at the time of recording

SS6: Array of Small Holographic Storage Materials

40-S1: Coupon Type Pattern Mask

The present invention relates to a recording and reproducing method in a holographic storage system. More specifically, in a coupon-type holographic data storage system, a boundary surface having a recording using each multiplexing method and having different refractive indices The present invention relates to a method for reproducing recorded hologram data using the property that total reflection occurs at an interface when light is incident at an angle greater than or equal to a critical angle.

As is well known, the technical field using holographic storage is being actively researched due to the remarkable development of components such as semiconductor lasers, charge-coupled devices (CCDs), and liquid crystal displays (LCDs). It is already being used as a fingerprint recognition system for storing and reproducing fingerprints, and is expanding to various fields that can apply the advantages of large storage capacity and ultra-high data transfer speed.

In such a holographic storage system, a total reflection (TR) hologram is constructed from the laser beam generated at the light source, as schematically shown in FIG. The signal light 1, which is one of these laser beams, is directed to the hologram recording layer 3 on the substrate 4 which is in optical contact with the large prism 5 via a mask transparecy 2. The other beam, the reference beam 6, proceeds through another surface of the large prism 5, causing total reflection from the surface of the hologram recording layer 3.

That is, the optical interference of the two beams is recorded by the photosensitive material of the hologram recording layer 3. Once the hologram is settled, the hologram can be reconstructed by irradiating the hologram with a laser beam traveling in a direction opposite to the original reference light 6. TR holograms have the ability to record and reconstruct images over large geometric areas.

FIG. 2 illustrates a reproduction method in a holographic storage device using a total reflection layer. Referring to FIG. 2, hologram data recorded in one hologram recording layer S1 may be reproduced using total reflection. That is, the reference light is irradiated through the mirror S3 to the hologram recording layer S1 to be reproduced during reproduction of the hologram data.

However, in order to manufacture the above-described holographic storage material, it is necessary to sequentially stack and etch the hologram recording layer S1 and the total reflection layer S2 in a plurality of process steps. In addition, when reproducing the hologram data recorded in the hologram recording layer S1, the hologram data to be reproduced should be irradiated with the reference light. However, there is a problem in that the irradiated reference light is not accurately positioned in the desired recording layer.

Accordingly, the present invention has been made to solve the above problems, the object of the coupon type holographic data storage system, by using the multiplexing method, and recording at an angle of more than the critical angle at the interface with different refractive index The present invention provides a recording and reproducing method in a holographic storage system capable of reproducing recorded hologram data by using the property of total reflection at the interface when the incident.

The recording and reproducing method of the holographic storage system according to an aspect of the present invention for achieving the above object, the first process of laminating the holographic storage material on the first protective layer when the holographic data is recorded, and lamination A second process of laminating a second passivation layer on the holographic storage material, and a third process of fabricating a mask on the second passivation layer. And an eleventh process of laminating a graphic storage material, a twelfth process of laminating a second protective layer on the laminated holographic storage material, and a third process of manufacturing the CCD on the second protective layer. It is characterized by.

In addition, the recording method in the holographic storage system according to another aspect of the present invention for achieving the above object is to place a protective layer for protecting the holographic storage material above and below the holographic storage material, the protection of the upper side In a state in which the mask is positioned on the layer, a thirty-first process of allowing signal light to be irradiated from above the mask; a thirty-second process of allowing the reference light to be incident on the critical surface of the lower left side of the lower protective layer at an arbitrary angle; And recording the hologram data generated by the interference with the reference light into the holographic storage material.

In addition, the regeneration method in the holographic storage system according to another aspect of the present invention for achieving the above object is to place a protective layer for protecting the holographic storage material above and below the holographic storage material, In the state where the CCD is positioned on the protective layer, the 81th step of irradiating the reference light from the critical plane on the lower left side of the lower protective layer at the same angle as the incident angle of the reference light at the time of recording, and by irradiating the holographic storage material And an eighty-eighth step of reproducing the recorded hologram data, and an eighty-seventh step of detecting the hologram data with respect to the reproduced reproduction signal light using a CCD.

Hereinafter, a plurality of embodiments of the present invention may exist, and a preferred embodiment will be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate the objects, features and advantages of the present invention through this embodiment.

FIG. 3 is a diagram illustrating a holographic storage material according to the present invention, in which a holographic storage material 20 is laminated on a protective layer 10, and a protective layer 30 on the holographic storage material 20. ) Is laminated. In this case, the light incident on the holographic storage material 20 is manufactured to satisfy the total reflection condition so that the total reflection is performed by the protective layers 10 and 30. The refractive index N1 of the protective layers 10 and 30 is smaller than the refractive index N2 of the holographic storage material 20.

That is, the total reflection condition must satisfy Equation 1 for total reflection of light incident from the critical plane in the law of refraction.

Here, Equation 1 is calculated by the law of refraction, and the law of refraction can be expressed as Equation 2 with reference to the drawings for the law of refraction shown in FIG. 4.

Therefore, when the holographic storage material 20 is manufactured, the refractive index of the holographic storage material 20 and the protective layers 10 and 30 are satisfied so as to satisfy the total reflection condition from the start of θ to the end of θ, which is a range of angles to be multiplexed. Adjust the refractive index.

5 is a diagram for a recording method in a holographic storage system according to the present invention.

That is, referring to FIG. 5, a holographic storage material 20 is laminated on the protective layer 10, and a protective layer 30 is laminated on the holographic storage material 20, and a mask is placed thereon. It is produced so that 40 is located. As described above, in the fabricated state, the signal light SS2 is irradiated from the upper side of the mask 40, and the reference light SS1 is incident at an arbitrary angle on the critical plane on the lower left side of the protective layer 10. do. Then, the signal light SS2 applied through the plurality of coupon type pattern masks 40-S1 and the protective layer 30 in the entire mask 40, and the reference light applied from the lower left side of the protective layer 10 ( The hologram data generated by the interference of SS1) can be recorded in the holographic storage material 20. 6 is a top view illustrating a plurality of coupon type pattern masks 40-S1 in the entire mask 40 shown in FIG. 5, and the number of coupon type pattern masks 40-S1 that can be multiplexed. I can make it.

5 and 6, a process of recording and producing by the multiplexing technique in the holographic storage system according to the present invention will be described.

First, the reference light SS1 is incident on the critical surface of the lower left side of the protective layer 10 of FIG. 5 with an arbitrary angle, and when the angle of the reference light incident for the multiplexing is changed, the holographic storage material 20 is changed. The angle of the reference light proceeding at is changed. At this time, the signal light SS2 is irradiated above the mask 40.

Then, the signal light SS2 applied through the plurality of coupon type pattern masks 40-S1 and the protective layer 30 in the entire mask 40, and the reference light applied from the lower left side of the protective layer 10 ( The hologram data generated by the interference of SS1 is recorded in the holographic storage material 20. Since the reference light SS1 can be changed, the holographic data can be recorded in the holographic storage material 20 by the multiplexing technique. Here, the holographic storage material 20 produced by recording the hologram data by the above-described process is cut by the size of the coupon type pattern mask 40-S1 shown in FIG. Can be made of material.

FIG. 7 illustrates a method for reproducing holographic data recorded in the holographic storage material 20 by FIGS. 5 and 6.

That is, referring to FIG. 7, the holographic storage material 20 is laminated on the protective layer 10, and the protective layer 30 is laminated on the holographic storage material 20, and the CCD is placed thereon. It is produced so that 50 is located.

As described above, in the prepared state, the reference light SS1 is irradiated from the critical plane on the lower left side of the protective layer 10 at the same angle as the incident angle of the reference light SS1 at the time of recording. Then, the hologram data SS4 recorded in the holographic storage material 20 is reproduced, and the reproduced reproduction signal light SS3 can be detected using the CCD 50.

Referring to FIG. 7, in more detail, when the hologram data recorded in the holographic storage material 20 is reproduced, when the reference light SS5 larger than the size of the light of the reference light at the time of recording is incident, the incident reference light is incident. The phase inversion method is used for SS5 and the phase is inverted by the protective layers 10 and 30 so that the hologram data SS4 is reproduced, and the reproduced reproduction signal light SS3 is detected using the CCD 50. You can do it. That is, in order to make the reference light accurately enter the hologram data recorded in the holographic storage material 20, the incident light is incident and reproduced by the reference light SS5 larger than the size of the light of the reference light at the time of recording.

FIG. 8 is a diagram illustrating hologram data being recorded and reproduced by directly using an array SS6 of a small holographic storage material to correspond to a mask according to another embodiment of the present invention. That is, although FIGS. 5 to 7 refer to a method of cutting a large holographic storage material when the holographic disk is manufactured, FIG. 8 illustrates an array SS6 of the small holographic storage material when the holographic disk is manufactured. After making a 1: 1 correspondence between the mask and the mask, recording and reproducing may be performed by applying the same technique of recording and reproducing hologram data as described in FIGS. 5 to 7.

Therefore, in the coupon type holographic data storage system, holographic data recorded using each multiplexing method is recorded by using the property that total reflection occurs at the interface when light is incident at an angle greater than or equal to the critical angle at the interface with different refractive indices. By reproducing, the production process using a single device is possible, so mass production is possible, and when reproducing hologram data from the produced holographic disc, the unit price of the disc can be lowered by reproducing with a simple device. The unit cost of the reproducing apparatus can be lowered, thereby reducing the economic burden.

In addition, since the present invention is disclosed as a right within the spirit and claims of the present invention, the present invention may include any modification, use and / or adaptation using general principles, and the present invention as a matter deviating from the description of the present specification. It includes everything that falls within the scope of known or customary practice in the art to which it belongs and falls within the scope of the appended claims.

As described above, the present invention is a coupon-type holographic data storage system, by using each multiplexing method, the total reflection occurs at the interface when the light incident at an angle greater than the critical angle at the interface with different refractive index By reproducing the recorded hologram data, mass production is possible because it enables the production process using a single device.When reproducing hologram data from the produced holographic disc, the device can be reproduced by a simple device. The unit cost can be lowered, and the unit cost of the reproducing apparatus can be lowered, thereby reducing the economic burden.

Claims (10)

In the method of manufacturing a holographic storage system to record and reproduce hologram data, Stacking the holographic storage material on the first protective layer; Stacking a second protective layer on the laminated holographic storage material; After fabricating the mask on the second protective layer, the signal light is irradiated from the upper side of the mask, and the reference light is incident on the critical surface of the lower left side of the first protective layer at an angle, and the signal light is incident. And recording the hologram data generated by the interference with the reference light to the holographic storage material. Stacking the holographic storage material on the first protective layer; Stacking a second passivation layer on the stacked holographic storage materials; After the CCD is placed on the second protective layer, the reference light is irradiated from the critical surface of the lower left side of the first protective layer at an angle equal to the incident angle of the reference light at the time of recording, by the irradiated reference light. Reproducing hologram data recorded on the holographic storage material, and detecting the hologram data using the CCD with respect to the reproduced reproduction signal light. Record and playback method in a holographic storage system comprising a. The method of claim 1, Wherein each of the first protective layer and the second protective layer is smaller than the refractive index of the holographic storage material. The method of claim 1, And said holographic storage material is made to correspond between said array of small holographic storage materials and said mask. In the recording method of the holographic storage system, A 31 st process of placing a protective layer for protecting the holographic storage material above and below the holographic storage material and irradiating signal light from above the mask in a state in which a mask is positioned on the upper protective layer; and, A thirty-second process of allowing the reference light to enter an incident angle at a critical plane of the lower left side of the lower protective layer; A thirty-third step of recording holographic data generated by the interference of the signal light and the reference light into the holographic storage material Recording method in a holographic storage system comprising a. The method of claim 4, wherein The mask is a recording method in a holographic storage system, characterized in that the number of coupon type pattern mask can be multiplexed. The method of claim 4, wherein And the reference light is irradiated so that total reflection occurs by the upper protective layer and the lower protective layer in the holographic storage material. The method of claim 6, The reference light is incident on the critical surface of the lower left side of the lower protective layer at an angle, and the incident reference light is changed and recorded in the holographic storage material by a multiplexing technique in the holographic storage system. How to record. In the reproduction method in a holographic storage system, The protective layer for protecting the holographic storage material is positioned above and below the holographic storage material, and the CCD is positioned on the upper protective layer, and the lower side is at the same angle as the incident angle of the reference light during recording. Step 81 of irradiating the reference light from the critical plane of the lower left side of the protective layer, Reproducing hologram data recorded in the holographic storage material by the irradiated reference light; Step 83 of detecting the hologram data with respect to the reproduced reproduction signal light using the CCD; Playback method in a holographic storage system comprising a. The method of claim 8, And the reference light uses a reference light larger than the size of the light of the reference light at the time of recording in order to accurately enter the holographic data recorded in the holographic storage material. The method of claim 9, And a phase inversion method is used for the reference light, and the phase is inverted by the upper protective layer and the lower protective layer so that hologram data is reproduced.

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