KR100749101B1 - Apparatus for recording of optical information, apparatus for reproducing of optical information and optical information storage medium - Google Patents

Abstract

An optical information recording apparatus, an optical information reproducing apparatus, and an optical information storing medium are provided to record optical information in the optical information storing medium and simultaneously record servo information in the optical information storing medium. A light source(101) emits one beam. The first and the second beam splitters(110,120) divide the beam into an information beam, a servo beam, and a reference beam. An SLM(Spatial Light Modulator)(130) loads data in the information beam. The information beam is inputted to an optical information storing area. The servo beam is inputted to a servo information storing area. The reference beam is simultaneously inputted to the optical information storing area and the servo information storing area. An interference pattern by the information beam and the reference beam is recorded in the optical information storing area. An interference pattern by the servo beam and the reference beam is recorded in the servo information storing area.

Description

Optical information recording apparatus, optical information reproducing apparatus and optical information storage medium {Apparatus for recording of optical information, Apparatus for reproducing of optical information and optical information storage medium}

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

2A is a schematic diagram showing recording of optical information and servo information in the embodiment of FIG.

FIG. 2B is a schematic diagram showing reproduction of optical information and servo information in the embodiment of FIG.

FIG. 3 is a schematic diagram illustrating reproduction of servo information when the optical information storage medium is tilted in the embodiment of FIG. 1.

4 illustrates an optical information storage area and a servo information storage area of an optical information storage medium according to an embodiment of the present invention.

5 is a block diagram showing an optical information recording and reproducing apparatus according to another embodiment of the present invention.

FIG. 6 illustrates recording of optical information and servo information to an optical information storage medium according to the embodiment of FIG. 5.

7 is a block diagram showing an optical information recording and reproducing apparatus according to another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

90: optical information storage medium 150: reference light optical system

100: light source system 160: servo light optical system

110: first optical splitter 170: detector

120: second light splitter 180: detector

130: spatial light modulator 190: reproduction light optical system

140: information light optical system

The present invention relates to an optical information recording apparatus, an optical information reproducing apparatus, and an optical information storage medium, and more particularly, to an optical information recording apparatus, an optical information reproducing apparatus, and an optical information storing apparatus capable of recording and reproducing servo information simultaneously with optical information. It is about the medium.

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

The holographic light processing apparatus separates light having coherency generated by a laser light source into an information beam carrying reference information and a reference beam, thereby simultaneously splitting the two lights onto the optical information storage medium. When incident, the spatial interference fringes of the two lights are recorded. When the optical information is reproduced, only the reference light is incident on the optical information storage medium. When the reference light is incident, the reference light is diffracted on the recorded interference fringe to reproduce the information light having the optical information.

Unlike conventional methods such as DVD, which stores brightness information one by one for each specific coordinate to store optical information, the holographic optical information processing apparatus uses Fourier transform method to convert the entire information of the plane. It is a mass storage technology that uses a page-oriented memory method that records at one point.

In addition, the holographic optical information processing apparatus uses a multiplexing technique, which is a technique of overlapping recording and reproduction of holograms at the same point in order to increase the recording density of data. Multiplexing techniques include angle multiplexing, phase-coded multiplexing, wavelength multiplexing, and shift multiplexing.

Here, the angle multiplexing method is to change the incident angle of the reference light incident on the optical information storage medium, the phase code multiplexing method is to spatially modulate the phase, and the wavelength multiplexing method is to store the optical information according to the wavelength change using a wavelength tunable laser The interference fringes recorded on the medium are changed, and the shift multiplexing is recorded while moving the optical information storage medium.

With the development of processing technology that can record a large amount of optical information on a small optical information storage medium by multiplexing method, etc., it is a reproducing technology that can accurately and quickly locate and reproduce a large amount of optical information recorded on the optical information storage medium. The importance of is highlighted.

Reproducing optical information from the optical information storage medium involves mechanical operations such as moving a stage, rotating a spindle, and moving a pick up system. Accordingly, the reproduction efficiency of the optical information is reduced due to the minute vibration of the device or the tilting of the optical information storage medium.

In order to accurately and quickly locate the position of the optical information recorded on the optical information storage medium, servo information including a clock signal and an address signal is simultaneously recorded to obtain the optical information. Promote efficient regeneration. The servo system recognizes the servo information recognized by the photodetector as focus error signal, tracking error signal, reproducing signal, etc. and adjusts the servo device so that the control system is suitable for reproducing optical information. And find the optical information storage location.

Configuration and servo control of the optical information processing apparatus in US Patent US 2006-0077857A1 "Optical information recording apparatus and method for recording optical information" filed by "Akiko Hirao" et al. It has been disclosed for the system.

As described above, it is important to record and reproduce the servo information in order to quickly correct the error by tilting the optical information storage medium and reproduce the optical information accurately and quickly.

An object of the present invention is to provide an optical information recording apparatus capable of recording optical information on an optical information storage medium and at the same time recording servo information.

Another object of the present invention is to provide an optical information reproducing apparatus capable of reproducing optical information of an optical information storage medium and simultaneously reproducing servo information.

Another object of the present invention is to provide an optical information storage medium capable of simultaneously recording optical information and servo information and simultaneously reproducing the optical information and the servo information.

An optical information recording apparatus according to an aspect of the present invention includes a light source for emitting light, a light splitter for separating the light into information light, servo light, and reference light, and a spatial light modulator for loading data into the information light. The information light is incident on the optical information storage area of the optical information storage medium, the servo light is incident on the servo information storage area of the optical information storage medium, and the reference light is simultaneously applied to the optical information storage area and the servo information storage area. Incidentally, the interference pattern by the information light and the reference light is recorded in the optical information storage area, and the interference pattern by the servo light and the reference light is recorded in the servo information storage area.

The direction of the information light incident on the optical information storage medium and the direction of the servo light may be different.

The optical information storage area and the servo information storage area of the optical information storage medium may be separated.

An optical information reproducing apparatus according to another aspect of the present invention injects reference light into an optical information storage medium including an optical information storage area and a servo information storage area, and generates optical information reproducing light in the optical information storage area and at the same time. The information storage region includes a light source for generating servo information reproduction light, a detector for detecting the optical information reproduction light and reproducing optical information, and a detector for detecting the servo information reproduction light and reproducing servo information.

The emission direction of the optical information reproduction light and the emission direction of the servo information reproduction light in the optical information storage medium may be different from each other.

An optical information storage medium according to another aspect of the present invention is a servo information storage layer for recording the interference pattern by the servo light and the reference light, an intermediate layer formed on top of the servo information storage layer to transmit one of the information light and the servo light, And an optical information storage layer formed on the intermediate layer and recording the interference pattern by the information light and the reference light.

Hereinafter, an optical information recording apparatus, an optical information reproducing apparatus, and an optical information storage medium according to the embodiment of the present invention configured as described above will be described. And the names of each component in the description of the following embodiments may be called other names in the art. However, if their functional similarity and identity, even if the modified embodiment can be seen as an equivalent configuration. In addition, the symbols added to each component is described for convenience of description. However, the contents shown in the drawings in which these symbols are described do not limit each component to the ranges in the drawings. Similarly, even if an embodiment in which the configuration on the drawings is partially modified is employed, it can be regarded as an equivalent configuration if there is functional similarity and identity.

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

1 is a block diagram showing an optical information recording and reproducing apparatus according to an embodiment of the present invention. In FIG. 1, the optical paths of the information light 240, the servo light 260 and the reference light 250 at the time of optical information recording are shown.

Referring to FIG. 1, the light source system 100 includes a light source 101 that emits light, a beam expander 102 that expands the light emitted from the light source 101, and a polarizer 103. As the light source 101, a He-Ne laser, an Ar laser, a semiconductor laser, or the like having good coherency may be used. The polarizing plate 103 is a λ / 2 plate so that the light has a uniform polarization component.

On the path of the light emitted from the light source system 100, a first light splitter 110 for separating the light into a temporary light and a reference light, a second light splitter 120 for separating the temporary light into an information light and a servo light, and a space. Spatial Light Modulator (SLM) 130 is provided.

The first light splitter 110 may be provided as a non-polarizer beam splitter, and the second light splitter 120 may be provided as a polarizer beam splitter.

The temporary light and the reference light separated from the first light splitter 110 include both P-polarized light and S-polarized light. The temporary light enters the second light splitter 120 through the shutter 151 which is opened during recording and closed during playback. In the second light splitter 120, the temporary light is separated into an information light having a P polarization component and a servo light having an S polarization component.

The information light transmitted through the second light splitter 120 is incident to the information light optical system 140. The information light optical system 140 includes a beam expander 141, a third light splitter 142, a relay lens 143 for information light, a phase mask 144, and a Fourier transform lens 145. do.

The information light enters the third light splitter 142 through the beam expander 141 extending to an area suitable for loading the optical information. The third light splitter 142 is preferably provided as a polarization type light splitter. The information light having the P polarization component transmitted through the third light splitter 142 is incident on the spatial light modulator 130. The spatial light modulator 130 is a reflective spatial light modulator that modulates incident light into P-polarized light and S-polarized light according to the on / off of a pixel. The information light incident on the spatial light modulator 130 is modulated to S-polarized light when the pixel of the spatial light modulator 130 is on and reflected to P-polarized light when the pixel is off. .

The information light of the S-polarized light reflected by the spatial light modulator 130 is refracted by the third light splitter 142 and is incident to the information light relay lens 143. The information light of the S-polarized light is passed through the relay lens 143 for information light, and high frequency noise is removed and transformed into parallel light rays. The information light passing through the information light relay lens 143 passes through the phase mask 144 for eliminating redundancy due to diffraction and is incident to the Fourier transform lens 145. The information light transmitted through the Fourier transform lens 145 is concentrated in a shape easy to interfere with and is incident on the optical information storage medium 90.

On the other hand, the reference light optical system 150 is a shutter for opening the optical information recording and closed when the optical information reproduction (Shutter) 151 and the rotating mirror reflecting the reference light separated from the first optical splitter 110 to the storage medium (90) 152 is provided. The reference light separated from the first light splitter 110 is reflected by the rotating mirror 152 as light having both a P polarization component and an S polarization component and is incident on the optical information storage medium 90. The rotating mirror 152 is preferably provided with a galvano mirror that can adjust the angle at which the reference light is incident on the optical information storage medium 90 for angular multiplexing.

The servo light optical system 160 includes the polarizing plate 161 for polarizing the servo light separated from the second light splitter 120, the fourth light splitter 162 for refracting the servo light to the storage medium 90, and the servo light. The reflective mirror 163 reflects to the fourth light splitter 162. The polarizing plate 161 is preferably provided as a λ / 2 plate to rotate the polarization component of the servo light by 90 degrees. The servo light separated by the second light splitter 120 is converted into a P polarization component while passing through the polarizing plate 161 as an S polarization component. The servo light is reflected by the reflection mirror 163 and enters the fourth light splitter 162. The fourth light splitter 162 is preferably provided as a non-polarization light splitter. The servo light refracted by the fourth light splitter 162 passes through the lens 191 and is incident to the optical information storage medium 90.

The optical path of the servo light may further include a spatial light modulator (not shown) capable of loading address information and servo information onto the servo light.

The reproducing light optical system 190 is preferably provided with a lens 191 which prevents the spread of the optical information reproducing light and a relay lens 192 for reproducing light which deforms the optical information reproducing light into parallel rays and removes high frequency noise.

It is preferable to include a detector 170 for reading optical information at the end of the optical path of the optical information reproduction light. The detector 170 detects reproduction light reproduced by reference light incident on the optical information storage medium 90, and includes a pixel array such as a charge-coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS). An image sensing device with a pixel array can be employed.

It is preferable to include a photodetector 180 at the end of the optical path through which the servo information reproduction light reproduced by the reference light incident on the optical information storage medium 90 passes through the third light splitter 142. . The detector 180 may be provided as a quadrant detector. The detector 180 discriminates the incident servo information reproduction light into a focus error signal, a tracking error signal, address information, and the like, and transmits the received servo information to a servo control system (not shown). .

2A is a schematic diagram showing recording of optical information and servo information in the embodiment of FIG.

Referring to FIG. 2A, an optical information storage medium 90 is formed on the servo information storage layer 93 and the servo information storage layer 93 for recording the interference pattern by the servo light and the reference light. An intermediate layer 91 that transmits one of the optical layers is formed on the intermediate layer 91, and an optical information storage layer 92 that records an interference pattern by the information light and the reference light.

The information light 240 is incident on one side of the optical information storage medium 90. The reference light 250 and the information light 240 form an interference pattern in the optical information storage area 245 of the optical information storage layer 92 of the optical information storage medium 90 to store optical information. The intermediate layer 91 of the optical information storage medium transmits the P-polarized component and blocks the S-polarized component. The S-polarized component of the information light 240 and the reference light is blocked by the intermediate layer 91.

The servo light 260 is incident on the other side of the optical information storage medium 90. The reference light 250 of the P-polarized light is transmitted through the intermediate layer 91 to interfere with the servo information 260 and the servo information storage area 265 of the servo information storage layer 93 of the optical information storage medium 90. To save the servo information. The servo light 260 transmits the intermediate layer 91 as a P polarization component, but does not generate an interference pattern because the polarization component is different from that of the information light 240.

Preferably, the servo light 260 is separated from the optical information storage layer 92 so that the optical information storage region 245 and the servo information storage region 265 are separated from each other in the optical information storage layer 92. .

FIG. 2B is a schematic diagram showing reproduction of optical information and servo information in the embodiment of FIG.

Referring to FIG. 2B, the reference light 250 is diffracted by the interference pattern of the optical information storage region 245 of the optical information storage layer 92 of the optical information storage medium 90 to generate optical information reproduction light 241. do. The optical information reproduction light has both an S-polarized component and a P-polarized component. The optical information reproducing light 241 of the P-polarized light component is transmitted to the detector 170 through the intermediate layer 91 of the optical information storage medium 90. The P-polarized component of the reference light 250 passes through the intermediate layer 91 of the optical information storage medium 90 and is diffracted by the interference pattern of the servo information storage region 265 of the servo information storage layer 93 so as to cause servo information. The reproduction light 261 is generated. The servo information reproduction light 261 passes through the intermediate layer 91 as a P polarization component and enters the detector 180. That is, the emission direction of the optical information reproduction light 241 and the emission direction of the servo information reproduction light 261 in the optical information storage medium 90 may be different from each other.

FIG. 3 is a schematic diagram illustrating reproduction of servo information when the optical information storage medium is tilted in the embodiment of FIG. 1.

Referring to FIG. 3, when the reference light 250 enters the servo information storage area 265 and regenerates the servo information reproduction light 261 in the optical information storage medium 90n in a normality state, the servo information reproduction is performed. Light 261 is incident on detector 180. When the servo information reproduction light 261 is incident on the detector 180 at the brightness of a normal state, the optical information reproduction light reproduced from the optical information storage medium 90n is reproduced normally without a tilting error.

When the reference light 250 enters the servo information storage area 265 and regenerates the servo information reproduction light 261 in the tilting storage medium 90a, the servo information reproduction light 261 has a weaker brightness than the normal state. Incident on the detector 180. The detector 180 transmits the tilting error information to a control system (not shown). A servo device (not shown) for correcting the tilting error may be operated to compensate for the tilting error. In addition, even when the reference light 250 is tilted and the incident angle to the optical information storage medium 90 is changed, the tilting error may be corrected as described above.

4 illustrates an optical information storage area and a servo information storage area of an optical information storage medium according to an embodiment of the present invention.

Referring to FIG. 4, an optical information storage area 245 in which interference patterns generated by the information light 240 and the reference light 250 are stored, and servo information in which the interference pattern generated by the servo light 260 and the reference light 250 are stored. The storage area 265 forms the track 310 in a parallel shape at regular intervals.

Hereinafter, another embodiment of the present invention will be described with reference to the accompanying drawings focusing on differences from the above-described embodiment of the present invention.

5 is a block diagram showing an optical information recording and reproducing apparatus according to another embodiment of the present invention.

Referring to FIG. 5, the path of the servo light passing through the optical information storage medium is transmitted to the optical information storage medium by allowing the servo light to directly enter the optical information storage medium 90 from the reflection mirror 163. To be provided. The fourth light splitter 162 may not be provided to inject the servo light into the optical information storage medium 90 in a straight line with the information light. Components other than those described above are the same as those of the embodiment of FIG. 1.

FIG. 6 illustrates recording of optical information and servo information to an optical information storage medium according to the embodiment of FIG. 5.

Referring to FIG. 6, the reference light 250 having both the P-polarized component and the S-polarized component stores optical information of the information light 240 of the S-polarized component and the optical information storage layer 92 of the optical information storage medium 90. An interference pattern is generated in the region 245 to store the optical information. The intermediate layer 91 of the optical information storage medium 90 transmits the P-polarized component and blocks the S-polarized component. The information light 240 is blocked by the intermediate layer 91 of the optical information storage medium 90 as the S polarization component. The P-polarized component of the reference light 250 passes through the intermediate layer 91 so that the P-polarized servo light 260 and the servo information storage area 93 of the servo information storage layer 93 of the optical information storage medium 90 are 265. ) Generates an interference pattern to store servo information. As shown in FIG. 2, the optical information storage area 245 and the servo information storage area 265 of the optical information storage medium 90 are different from each other when the servo light and the information light entering the optical information storage medium 90 are opposite to each other. ) May be generated on the same axis.

7 is a block diagram showing an optical information recording and reproducing apparatus according to another embodiment of the present invention.

Referring to FIG. 7, a light source system 100 that emits light, a first light splitter 110 that splits the light into a temporary light and a reference light, and a second light splitter splitting the temporary light into an information light and a servo light ( 120, a spatial light modulator 130 for loading data into the information light, an information light optical system 140 for transmitting the information light to one side of the optical information storage medium 90, an optical information storage medium 90, and reproduction The optical optical system 190 and the detector 170 are provided on one axis.

The reference light optical system 150 and the servo light optical system 160 may further include reflective mirrors 153 and 163 for reflecting the reference light and the servo light. The polarizing plate 161 of the servo light optical system 160 may not be provided.

The spatial light modulator 130 is a TFT LC (Thin Film Transistor Liquid Crystal), a passive matrix STN LC (Super Twisted Nematic Liquid Crystal), ferroelectric LC (ferro Liquid Crystal), Polymer Dispersed Liquid Crystal (PDLC) It is preferable to be provided with a transmissive spatial light modulator such as plasma driven liquid crystal (PALC).

The sensor 180 for reading the servo information reproduction light reproduced by the optical information storage medium 90 by reference light is preferably provided at one side of the third light splitter 142.

Unlike the case where the optical information storage medium 90 includes a reflective spatial light modulator, the optical information storage medium 90 may include an intermediate layer, an optical information storage layer, and a servo information storage layer capable of transmitting the S-polarized component and blocking the P-polarized component. Do.

Components other than those described above are provided in the same manner as described in the embodiment of FIG. 1.

The information light transmitted through the first light splitter 110 and the second light splitter 120 passes through the spatial light modulator 130 and the information light optical system 140 to allow the optical information storage medium 90 of the optical information storage medium 90 to pass through. Incident on one side. The information light has a P polarization component.

The reference light separated by the first light splitter 110 has both the P polarization component and the S polarization component and is refracted by the reflection mirror 153 and the rotating mirror 152 to be incident on the optical information storage medium 90. The servo light separated by the second light splitter 120 has an S polarization component and is refracted by the reflection mirror 163 and the fourth light splitter 162 to be incident on the optical information storage medium 90.

The information light of the P polarization component and the P polarization component of the reference light form an interference pattern in the optical information storage region 245 of the optical information storage layer 92 of the optical information storage medium 90 to store optical information. The information light is blocked by the intermediate layer 91 of the optical information storage medium 90 as a P polarization component. The S-polarized component of the reference light passes through the intermediate layer 91 to form an interference pattern in the servo light and the servo information storage area 265 of the servo information storage layer 93 of the optical information storage medium 90 to generate servo information. Save it.

When the optical information is reproduced, the shutter 151 is closed to block the information light and the servo light, and only the reference light is incident on the optical information storage medium 90. The reference light has both a P polarization component and an S polarization component. The reference light is diffracted by the interference pattern of the optical information storage region 245 of the optical information storage layer 92 of the optical information storage medium 90 to generate optical information reproduction light. The S-polarized component of the optical information reproduction light passes through the intermediate layer 91 of the optical information storage medium 90 and enters the detector 170. The S-polarized component of the reference light passes through the intermediate layer 91 and is diffracted by the interference pattern of the servo information storage region 265 of the servo information storage layer 93 to generate servo information reproduction light. The servo information reproduction light is transmitted through the intermediate layer 91 as the S-polarized component and refracted by the third light splitter 142 to be incident to the detector 180.

Although the optical information recording and reproducing apparatus has been described above, the optical information recording and reproducing apparatus may be configured by removing the detector 170, the detector 180, and the reproducing optical system 190. In addition, the optical information reproducing apparatus may be configured by removing the second optical splitter 120, the spatial light modulator 130, the information optical optical system 140, and the servo optical optical system 160.

As mentioned above, preferred embodiments of the present invention have been described in detail, but those skilled in the art to which the present invention pertains should understand the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that various modifications or changes can be made. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

As described above, according to the present invention, since the light emitted from one light source is separated into information light, servo light, and reference light, it is possible to prevent the high cost and complexity of the device by separately providing a light source for storing servo information. By recording the optical information and the servo information at the same time, the servo information necessary for the optical information reproduction can be easily extracted, so that the optical information can be reproduced accurately and quickly.

Claims (6)

An optical information recording apparatus using an optical information storage medium having an optical information storage area and a servo information storage area, A light source emitting one light; A light splitter that separates the light into information light, servo light, and reference light; And A spatial light modulator for loading data into the information light, The information light is incident on the optical information storage area, The servo light is incident on the servo information storage area, The reference light is incident on the optical information storage area and the servo information storage area at the same time, The interference pattern by the information light and the reference light is recorded in the optical information storage area, And an interference pattern formed by the servo light and the reference light in the servo information storage area. The optical information recording apparatus according to claim 1, wherein the direction of the information light incident on the optical information storage medium and the direction of the servo light are different from each other. The optical information recording apparatus of claim 1, wherein the optical information storage area and the servo information storage area of the optical information storage medium are separated from each other. An optical information reproducing apparatus using an optical information storage medium having an optical information storage area and a servo information storage area, A light source injecting one reference light into the optical information storage area and the servo information storage area to generate optical information reproduction light in the optical information storage area and to generate servo information reproduction light in the servo information storage area; A detector which detects the optical information reproduction light and reproduces the optical information; And And a detector for detecting the servo information reproducing light and reproducing the servo information. The optical information reproducing apparatus according to claim 4, wherein an emission direction of the optical information reproducing light and an emission direction of the servo information reproducing light in the optical information storage medium are different from each other. A servo information storage layer for recording the interference pattern by the servo light and the reference light; An intermediate layer formed on the servo information storage layer to transmit one of the information light and the servo light; And And an optical information storage layer formed on the intermediate layer and recording an interference pattern by the information light and the reference light.

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