KR100278066B1 - Composite volume holographic digital storage/reproducing system - Google Patents

Abstract

The present invention generates a backup (or copy) reference light by branching the reference light for recording and reproduction, and generates a backup (or copy) signal light by branching the signal light, and storing the recording based on the generated backup reference light and the backup signal light. A multi-volume holographic digital storage and reproducing system for backing up (or copying) hologram data reproduced on a medium to a backup (or copy) storage medium. To this end, the present invention relates to a recording storage in a reproducing system. A recording medium having a medium and a backup (or copying) storage medium, and having an optical path for performing processing of recording or reproducing data and another optical path for performing processing of backup or copying data; Enhances the efficiency of the system by allowing the recorded data to be backed up or copied to backup storage media Of course, it is possible to realize effective management of the hologram data recorded in the storage medium.

Description

Compound Volume Holographic Digital Storage and Playback System {COMPOSITE VOLUME HOLOGRAPHIC DIGITAL STORAGE / REPRODUCING SYSTEM}

The present invention relates to a volume holographic digital data storage / reproducing system, and more particularly to backing up or storing holographic data recorded on a storage medium (for example, an optical refractive crystal). A multi-volume holographic digital storage and playback system suitable for copying holographic data recorded on a medium.

Recently, the field of technology using volume holographic digital data storage has been actively researched everywhere due to the remarkable development of semiconductor laser, charge coupled device (CCD), liquid crystal display (LCD), etc. As a result of these studies, fingerprint recognition systems for storing and reproducing fingerprints have been put into practical use, and they are expanding to various fields that can apply the advantages of large storage capacity and ultra-high data transfer speed.

The volume holographic digital storage and reproducing system as described above is a storage medium, for example, optical refraction, in which an interference fringe generated when the signal light from a target object and a reference light interfere with each other is sensitive to the amplitude of the interference fringe. By recording in a storage medium such as a crystal, recording the intensity and phase of the signal light by a method of changing the angle of the reference light, etc., it is possible to display a three-dimensional image of an object and to display a page of binary data ( Hundreds to thousands of holograms can be stored in the same place.

FIG. 2 illustrates a typical conventional volume holographic digital storage for storing three-dimensional hologram data (ie, interference fringes) in a storage medium by using interference between signal light and reference light, and reproducing three-dimensional hologram data stored in the storage medium. The overall schematic of the regeneration system is shown.

As shown in the figure, a conventional volume holographic digital storage and reproducing system includes a light source 202 for generating laser light required in holography and a storage medium for storing three-dimensional hologram data (i.e., interference fringes). 230 (eg, a light refractive crystal), and between the light source 202 and the storage medium 230, two paths including respective optical systems, that is, the reference light processing path PS1 and the signal light processing path ( PS2) is formed.

Referring to FIG. 2, the optical splitter 204 splits the laser light generated and emitted from the light source 202 into the reference light and the signal light, wherein the divided reference light is provided to the reference light processing path PS1 and is divided into the signal light. Is provided to the signal light processing path PS2.

Next, on the reference light processing path PS1, a waste construction lens 206, a beam expander 207 of two lenses, and a reflecting mirror 208 are sequentially provided in the emission direction of the reference light, and the reference light processing path having such an optical structure. In PS1, reference light required for recording or reproducing hologram data is generated and provided to the storage medium 230.

That is, the reference light branched from the optical separator 204 is adjusted through the waste construction lens 206 and then expanded to a predetermined size through the beam expander 207, for example, the beam expander in the signal light processing path PS2 described later. The reference light is extended to a size sufficient to cover the size of the signal light extending through, and the expanded reference light is transmitted to the reflector (208).

On the other hand, the reflector 208 deflects the reference light (beam) extended to a predetermined size through the beam expander 207 at a predetermined angle, for example, a recording angle during recording or a predetermined reproduction angle for reproduction. Reference light deflected at an angle or reproduction angle is provided to the storage medium 230.

At this time, the reference light used during recording or reproduction is controlled by rotating the reflector 208 to change the deflection angle θ each time binary data of each page unit is recorded. Hundreds to thousands of holograms can be stored or played back on the storage medium 230.

Here, the angle adjustment of the reflector 208 is performed by the motor 210 driven by the actuator 210, the deflection angle θ of the reference light is an angle measuring device (for example, attached to a predetermined portion of the motor). , Encoder).

On the other hand, on the signal light processing path PS2, a reimaging lens 214, a beam expander 216, a reflector 218, a beam expander 220, and a spatial light modulator 222 are sequentially provided in the emission direction of the signal light. In addition, a field lens 224 and a Fourier lens 226 are sequentially provided between the spatial light modulator 222 and the storage medium 230. In the signal light processing path PS2 having such an optical structure, the hologram data is recorded at the time of recording. In addition, the storage medium 230 provides a modulated signal light obtained by modulating the signal light in units of one page of light and dark binary data constituting pixels according to external input data applied to the spatial light modulator 222.

That is, the signal light branched from the optical separator 204 is reimaged through the reimaging lens 214, and firstly expanded to a predetermined size through the beam expander 216, and the signal light thus expanded first is reflected mirror 218. Is reflected at a predetermined deflection angle. The first extended signal light reflected by the reflector 218 is then second extended through the beam expander 220 and then transmitted to the spatial light modulator 222 (eg, LCD).

In this case, extending the signal light through the two beam expanders 216 and 220 to a predetermined size is generated by the laser light from the light source 202 and branched through the light separator 204 so that the size of the signal light is very small. This is because it is inadequate to perform optical modulation in, and the branched signal light is expanded to a size corresponding to the size of the spatial light modulator 222 through this second-order expansion.

On the other hand, the spatial light modulator 222 modulates the extended signal light transmitted from the beam expander 220 in units of one page of binary data of light and shade binary data formed by pixels according to data input from the outside. The extended signal light incident on the spatial light modulator 222 when the image data is one frame unit of the image is modulated by one frame unit.

Then, the signal light modulated in units of one page of binary data output from the spatial light modulator 222 is adjusted to be suitable for storage in the storage medium 230 through the field lens 224 and the Fourier lens 226. Next, in synchronization with the reference light incident on the reflector 208 of the reference light processing path PS1, the light is incident on the storage medium 230.

Therefore, in the storage medium 230, in the recording mode, the signal light provided from the Fourier lens 226 is obtained through the interference between the recording reference light incident from the reflector 208 with the corresponding deflection angle θ. Interference fringes are recorded. That is, the light induced phenomenon of the kinetic charge occurs in the storage medium 230 according to the intensity of the interference fringe obtained by the interference between the signal light and the recording reference light. An interference fringe of the hologram data is recorded.

Further, in the storage medium 230, when the reproduction reference light is incident at the predetermined deflection angle θ from the reflecting mirror 208 at the reproduction mode, the recorded interference fringe diffracts the reproduction reference light to produce the original pixel. Demodulate one page of binary data (that is, a checkered pattern) composed of light and dark.

Therefore, in the reproducing mode, the three-dimensional image demodulated in units of one page of binary data reproduced from the storage medium 230 is reimaged through the reimaging lens 232 and then the CCD (Charge Coupled Device: 234) or the like. By irradiation, the original data, i.e., the electric signal, is restored. At this time, the reference light used to reproduce the data recorded in the storage medium 230 should be a reference light having substantially the same angle as the reference light applied when recording the hologram data in the storage medium 230.

PCs, on the other hand, support the ability to back up (or automatically back up) data when saving data to a hard disk or to copy data from a hard disk to a floppy disk (or floppy disk to hard disk). Therefore, PC users can utilize this backup function or copy function to perform effective data management.

Therefore, in the case of the above-mentioned PC, even in a volume holographic digital storage and reproducing system, the data recorded when recording the hologram data is backed up (or automatically backed up) or the hologram data recorded on the storage medium is transferred to another storage medium. If the function of copying can be supported, the user's use efficiency can be improved, and the hologram data recorded in the storage medium can be effectively managed.

However, in the conventional storage and reproducing system as described above, there is currently no consideration regarding the aspects related to the backup of the hologram data and the technique of copying the recorded hologram data to another storage medium.

Accordingly, the present invention devised in view of the above-described point, the present invention is to divert the reference light for recording and reproduction to generate a backup (or copy) reference light, and to branch the signal light to generate a backup (or copy) signal light, There is provided a multi-volume holographic digital storage and reproducing system capable of backing up (or copying) hologram data reproduced from a recording storage medium on the basis of the backup reference light and the backup signal light. There is a purpose.

In order to achieve the above object, the present invention provides a hologram which aims by diverting laser light generated from a light source into a reference light and a signal light, and interfering a modulated signal light obtained by modulation between the branched signal light and the input data and the branched reference light. A volume holographic digital storage and reproduction system for recording data, comprising: a first optical separator for splitting laser light generated by the light source to generate reference or signal light for recording or reproduction; A first reference light processing path for deflecting the branched reference light at a predetermined deflection angle and entering the recording storage medium as a recording or reproducing reference light; A first signal light processing path for generating a modulated signal light through modulation between the branched signal light and external input data, the first modulated light signal being incident on the recording medium in synchronization with the reference light; A reproduction output system for restoring a reproduction output reproduced on the recording storage medium to an original signal before modulation in a backup or copy mode; A second optical splitter for splitting the branched reference light into the recording or reproducing reference light and a backup or copy reference light; A second reference light processing path for deflecting the branched backup or copy reference light at a predetermined deflection angle to enter the backup or copy storage medium; A third optical splitter for splitting the branched signal light into the recording signal light and the backup or copy signal light; And generating a backup or copy signal light by modulating between the branched backup or copy signal light and the restored reproduction hologram data provided from the reproduction output system in the backup or copy mode, and generating the generated backup or copy signal light. A second signal light which enters into said backup or copy storage medium in synchronization with said backup or copy reference light and records reproduction hologram data in said recording storage medium for backup or copy to said backup or copy storage medium; A composite volume holographic digital storage and playback system consisting of processing paths is provided.

1 is an overall schematic diagram of a complex volume holographic digital storage and playback system in accordance with a preferred embodiment of the present invention;

2 is an overall schematic diagram of a typical conventional volume holographic digital storage and playback system.

<Description of the code | symbol about the principal part of drawing>

102: light source 104,110,122: optical separator

106: waste configuration lens 108116120: beam expander

114,132: Reimaging lens 118,140,144,148,150: Reflector

123,146: Shutter 124,152: Spatial Light Modulator

126,154: field lens 128,156: Fourier lens

130, 158: storage medium 134: CCD

136: playback processing block

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows an overall schematic diagram of a complex volume holographic digital storage and playback system according to a preferred embodiment of the present invention.

As shown in the figure, the complex volume holographic digital storage and reproducing system of the present invention has four signal processing paths when classified broadly, i.e., reference light processing between the light source 102 and the recording medium 130 for recording. A path PS1 and a signal light processing path PS2 are formed, and a backup (or copy) reference light processing path PS3 and a backup (or copy) between the light source 102 backup (or copy) storage medium 158. ) The signal light processing path PS4 is formed.

At this time, data from the outside (hologram data to be recorded) is input to the spatial light modulator 124 in the signal light processing path PS2, and to the spatial light modulator 152 in the backup signal light processing path PS4. In the backup mode or the copy mode, hologram data reproduced from the recording storage medium 130 is input.

Referring to FIG. 1, unlike the structure of the reference light processing path PS1 in the conventional system of FIG. 2 described above, the reference light processing path PS1 is a waste construction lens 106 and a beam expander having two lenses. 108, the optical separator 110 and the acoustic wave modulator 112 are sequentially provided in the direction of incidence from the output side of the reference light to the recording medium 130, and the hologram data in the reference light processing path PS1 having such an optical structure. The reference light required for recording or reproducing is generated and incident to the recording storage medium 130.

That is, the reference light branched from the optical separator 104 is adjusted through the waste construction lens 106 and then expanded to a predetermined size through the beam expander 108, for example, the beam expander in the signal light processing path PS2 described later. The reference light is extended to a size sufficient to cover the size of the signal light extending through, and is transmitted to the optical splitter 110.

In this case, the optical splitter 110 splits the extended reference light into two reference lights, that is, a reference light for recording or reproducing and a backup or copying reference light. Is transmitted to the backup (or copy) reference light processing path PS3, which will be described later.

Next, in the acoustic wave modulator 112, in the recording mode, the reproducing mode, and the copying mode, the reference light branched from the optical separator 110 is pre-set for a predetermined angle, for example, a recording angle or reproduction during recording. The reference light deflected at the set reproduction angle and deflected at the recording angle or the reproduction angle is provided to the storage medium 130.

Here, the sound wave light modulator 112 may use, for example, a solid crystal as a medium, and induces a density difference of the medium by appropriately controlling the frequency of sound waves generated from the sound source, and the density of the medium. By the difference, the refractive index of the incident light (that is, the reference light) is changed, that is, the reference light is refracted at a predetermined deflection angle. The refractive index control in this acoustic wave modulator 112 is in accordance with the control signal CS1 from the system controller, not shown.

At this time, the reference light used at the time of recording or reproduction is controlled by changing the refractive index of the reference light each time the binary data of each page unit is recorded.

On the other hand, the signal light processing path PS2 includes an optical splitter 122 which splits the signal light extended by the beam expander 120 into two signal lights, namely, a recording signal light and a backup (or copy) signal light, and an optical light in the radiation mode. Except that the shutter 123 is formed between the beam expander 120 and the spatial light modulator 124 to block the signal light branched from the separator 122 from exiting to the recording storage medium 130 side. It is substantially the same as the structure of the signal light processing path PS2 in the conventional system shown in FIG. That is, the shutter 123 maintains the cutoff state only in the copy mode, and keeps the open state in other modes.

Thus, in this signal light processing path PS2, in the recording mode, the modulated signal light generated through the modulation between the branched signal light and the external input data is transferred from the above-described acoustic wave modulator 112 to the recording medium 130 for recording. It enters into the recording storage medium 130 in synchronization with the incident reference light. As a result, hologram data targeted for recording in the recording mode will be recorded in the recording storage medium 130.

At this time, the backup (or copy) signal light branched by the optical separator 122 for splitting the expanded signal light into the recording signal light and the backup or copy signal light is used for backup (or copy), which will be described later in the backup mode or copy mode. It is transmitted to the signal light processing path PS4.

On the other hand, the backup reference light processing path PS3 which generates the backup (or copy) reference light and provides the backup storage medium 158 to the backup storage medium 158 when the system is in the backup mode or the copy mode, receives the backup reference light branched from the optical separator 110. A reflector 140 and a sound wave light modulator 142 reflecting at a predetermined angle, wherein the sound wave light modulator 142, in the backup mode or the radiation mode, the back-up reference light reflected through the reflector 140 A deflection [theta] 2 at a predetermined angle set, for example, a recording angle at the time of backup or copying, and the backup reference light deflected at the recording angle is incident on the backup (or copying) storage medium 158.

At this time, the recording angle of the backup reference light has the same deflection angle as the recording angle (or reproduction angle) of the hologram data to be backed up or copied.

On the other hand, the backup signal light processing path PS4 which generates the backup (or copy) signal light and provides the backup storage medium 158 to the backup storage medium 158 when the system is in the backup mode or the copy mode is the backup signal light branched from the optical separator 122. The reflector 144, the shutter 146, the reflector 148, the reflector 150, the spatial light modulator 152, the field lens 154, and the Fourier lens 156 are sequentially arranged in the exit direction. . Here, the shutter 146 maintains the open state only in the backup mode or the copy mode under the control from the system controller (not shown) and keeps the shut off state in other modes.

Accordingly, the backup (or radiation) signal light branched from the optical separator 122 in the backup mode or the copy mode is transmitted to the spatial light modulator 152 through the reflector 144, the opening of the shutter 146, and the two reflectors 148 and 150. Is delivered.

On the other hand, the hologram data reproduced in the recording medium 130 in the backup mode or the copy mode is restored to an electrical signal through a reproduction output path including the reimaging lens 132 and the CCD 134, and thus restored. The hologram data is provided to the reproduction processing block 136, and the reproduction processing block 136 provides the spatial data modulator 152 with final data (ie, an electrical signal) obtained after a signal processing process such as error correction. .

Therefore, in the spatial light modulator 152, as in the spatial light modulator 124 on the reference light processing path PS2 side, the backup signal light reflected from the reflector 150 and the input data provided from the reproduction processing block 136 ( That is, modulated signal light is generated through modulation between reproduction data to be backed up or copied, and the generated modulated signal light is transmitted to the storage medium 158 for backup via the field lens 154 and the Fourier lens 156. Incident.

As a result, in the backup storage medium 158, the backup reference light having the predetermined deflection angle [theta] 2 and the modulated signal light are incident in synchronization, whereby the hologram data (i.e., recording storage) to be backed up or copied by the user is selected. Hologram data reproduced on the medium 130) is recorded.

That is, as can be seen from the above, the present invention uses the reference light processing path PS1 and the signal light processing path PS2 to perform data recording and reproduction of the recording storage medium 130, Or recording and reproducing data for the backup (or copy) storage medium 158 for backup (or copy) using the reference light processing path PS3 and the backup (or copy) signal light processing path PS4. Backup mode, playback mode, and copy mode can be selectively performed.

As described above, according to the present invention, there is provided a recording medium and a backup (or copy) storage medium in a reproduction system, and an optical system path for processing data for recording or reproduction and processing of reproduction data for backup or copying. By providing a different optical path for performing the data, the data recorded on the recording storage medium can be backed up or copied whenever necessary as a backup storage medium, thereby improving the utilization efficiency of the entire system as well as the hologram data recorded on the storage medium. Effective management can be realized.

Claims (4)

Volume holographic digital storage for branching the laser light generated from the light source into the reference light and the signal light, and interfering the modulated signal light obtained by the modulation between the branched signal light and the input data and the branched reference light with each other to record the desired hologram data; In a playback system, A first optical separator for splitting the laser light generated by the light source to generate a reference or signal light for recording or reproduction; A first reference light processing path for deflecting the branched reference light at a predetermined deflection angle and entering the recording storage medium as a recording or reproducing reference light; A first signal light processing path for generating a modulated signal light through modulation between the branched signal light and external input data, the first modulated light signal being incident on the recording medium in synchronization with the reference light; A reproduction output system for restoring a reproduction output reproduced on the recording storage medium to an original signal before modulation in a backup or copy mode; A second optical splitter for splitting the branched reference light into the recording or reproducing reference light and a backup or copy reference light; A second reference light processing path for deflecting the branched backup or copy reference light at a predetermined deflection angle to enter the backup or copy storage medium; A third optical splitter for splitting the branched signal light into the recording signal light and the backup or copy signal light; And In the backup or copy mode, a backup or copy signal light is generated through modulation between the branched backup or copy signal light and the restored reproduction hologram data provided from the reproduction output system, and the generated backup or copy signal light is generated. A second signal light which enters into said backup or copy storage medium in synchronization with said backup or copy reference light and records reproduction hologram data in said recording storage medium for backup or copy to said backup or copy storage medium; Complex volume holographic digital storage and playback system with processing paths. The recording medium of claim 1, wherein the first signal light processing path further includes a first shutter that prevents the signal light branched through the third optical separator from being emitted to the recording medium in the backup or copy mode. Composite volume holographic digital storage and playback system. The storage medium for a backup or copy according to claim 1, wherein the second signal light processing path includes the backup or copy signal light branched through the third optical separator when the hologram data is recorded on the recording storage medium. And a second shutter to block output from the multiple volume holographic digital storage and playback system. 4. The composite volume holo of claim 1, 2 or 3, wherein the branched reference light and the branched back-up or radiation reference light are respectively deflected at a predetermined deflection angle through respective acoustic wave modulators. Graphical digital storage and playback system.

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