KR100787755B1 - Apparatus for processing optical information and method of reading optical information - Google Patents

Abstract

A device for processing optical information and an optical information reproducing method are provided to perform servo control for reproducing optical information by using a beam reproduced at a selected recording area and a beam reproduced at an adjacent recording area in a track of the selected recording area. An optical information processing device(100) comprises a light source(110), a polarized beam splitter(120), a reference optical system(130), a reading unit(150), and a multiplexing unit(160). The polarized beam splitter splits the beam into a signal beam and a reference beam. The reference optical system sends the reference beam to an area including a specific recording area and a pair of recording areas adjacent to the specific area at an optical information storage medium having a plurality of recording areas in a track direction. The reading unit detects a reproduced beam at the specific recording area by the reference beam, and peripheral beams reproduced at the adjacent recording areas. The multiplexing unit controls incident condition of the reference beam by comparing the degrees of the peripheral beams detected by the reading unit.

Description

Apparatus for processing optical information and method of reading optical information}

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

2 is a block diagram showing a digital signal processor of the optical information processing apparatus according to the present invention.

3 is a flowchart showing optical information reproduction by the optical information processing apparatus according to the present invention.

4 is a simplified diagram showing an ideal state of light detected by the ambient light detector when the optical information is reproduced in the optical information processing apparatus according to the present invention.

5 is a simplified diagram showing an actual state of light detected by an ambient light detector when optical information is reproduced in the optical information processing apparatus according to the present invention.

FIG. 6 is a graph illustrating a change in light amount according to a time change of ambient reproduction light detected by the ambient light detector illustrated in FIG. 5.

7 is a graph for compensating for a time delay of ambient reproduction light detected by an ambient light detector in the optical information processing apparatus according to the present invention.

** Description of the symbols for the main parts of the drawings **

100: optical information processing device

110: light source

120: polarized light splitter

130: reference optical system

140: signal optical system

150: reading unit

160: multiplexing control unit

The present invention relates to an optical information processing apparatus, an optical information reproducing method, and an optical information recording method. More particularly, each optical information adjacent to a track is reproduced at a multiplexing angle having different offset angles. The present invention relates to an optical information processing apparatus, an optical information reproducing method, and an optical information recording method for performing servo control by using reproduction light reproduced together by adjacent optical information.

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 optical information processing apparatus receives an optical modulated signal beam and a reference beam that intersects the signal light to form an interference fringe on the storage medium, and enters the storage medium to store data. do. In the reproduction of data, only the reference light is incident on the interference fringe of the storage medium so that data input to the storage medium is output by diffraction generated from the interference fringe.

In order to increase the recording capacity, the holographic optical information processing apparatus may store data in a multiplex by irradiating a reference light to one beam spot at different angles. The multi-input data can be output by irradiating only the reference light at different angles during reproduction. In other words, the holographic light processing device is a supercapacitive data storage device capable of inputting and outputting data in a multi-layered and overlapping state at one light spot.

The holographic optical information processing apparatus uses a method of multiplexing light in order to increase the recording density of data. Methods of multiplexing light include angular multiplexing, phase-code multiplexing, wavelength multiplexing, shift multiplexing, and the like.

Here, the angular multiplexing method is to multiplex by changing the angle of incidence of the reference light, the phase code multiplexing is to multiplex by modulating the phase spatially, the wavelength multiplexing is to multiplex according to the wavelength change using a wavelength tunable laser, the shift multiplexing It is a method of multiplexing records while moving a storage medium.

An angle multiplexing method is disclosed in Korean Patent Laid-Open No. 10-2005-0102748, Holographic Information Recording / Reproducing Device. On the other hand, when reproducing the multiplexed and recorded optical information, not only the optical information of the selected recording area but also the optical information of an unselected adjacent recording area can be partially reproduced together.

In this case, since the optical information of the non-selected recording area becomes a noise component during reproduction, the reproduction efficiency of the optical information reproduced in the selected recording area can be reduced. In order to prevent this, there is a technique of blocking light reproduced in a recording area that is not selected.

Prior arts for this include International Application Publication No. "WO2004 / 102541", "High data density volumetric holographic data storage method and system" filed by "Thomson licensing company". In the case of the international publication, it is disclosed that a filter is used to block light reproduced in an unselected recording area.

On the other hand, servo control must be made for accurate reproduction of the recorded holographic optical information. The prior art for this is disclosed in US Patent No. 2005-0030876, Optical Information Recording Apparatus and Optical Information Reproducing Apparatus, filed and filed by Japan's "Optware." The U.S. Patent Publication discloses using a separate laser light source for servo control.

However, as mentioned, the U. S. Patent uses a separate laser light source for servo control, which complicates the configuration of an optical system and a device for servo control, and also uses a light source for servo control having a different wavelength. There is also a problem that becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to use light reproduced in a recording area adjacent to a track of a selected recording area together with light reproduced in a selected recording area during reproduction of optical information. The present invention provides an optical information processing apparatus and an optical information reproducing method that enable servo control for reproducing optical information.

An optical information processing apparatus according to the present invention for achieving the above object comprises a light source for emitting light; A polarized light splitter that separates the light into a reference light and a signal light; A reference optical system for injecting the reference light to include a specific recording area and a pair of other recording areas adjacent to the specific recording area in an optical information storage medium having a plurality of recording areas adjacent to each other in a track direction; A reading unit detecting reproduction light reproduced in the specific recording area by the reference light and ambient reproduction light reproduced in a pair of recording areas adjacent to the specific recording area; And a multiplexing controller for comparing the amount of light of the pair of ambient reproduction light detected by the reading unit with each other to control the incident condition of the reference light.

The reading unit includes: a wave plate for switching the polarization state of the reproduction light and the ambient reproduction light; A regenerated light filter separating the regenerated light passing through the wave plate and the ambient regenerated light and passing the ambient regenerated light to the wave plate; An ambient light detector for detecting the ambient reproduction light passing through the wave plate; And a reproduction light detector for detecting the reproduction light separated by the reproduction light filter.

The ambient light detector includes: a first photodiode for detecting ambient reproduction light reproduced in another recording area adjacent to one side of the recording area where the reproduction light is reproduced; And a second photodiode for detecting ambient reproduction light reproduced in another recording area adjacent to the other side of the recording area where the reproduction light is reproduced, wherein the first and second photodiodes are divided into a plurality of subphotodiodes. It is composed.

The multiplexing control unit may include: a power meter for detecting the amount of light detected by the first and second photodiodes; An anti-aliasing filter for adjusting the signal detected by the power meter; And a digital signal processor which reads the signal adjusted by the anti-aliasing filter and controls the incident condition of the reference light.

The digital signal processor includes an AD converter for converting a signal adjusted by the anti-aliasing filter; A low pass filter for removing an unnecessary signal from the signal changed by the AD converter; An angle error calculator for analyzing the signal passing through the low pass filter to determine a servo state of the reference light; And a controller for controlling an incident condition of the reference light according to the servo state of the reference light.

The digital signal processor controls the incident condition of the reference light according to a generation time difference between the maximum light amount of ambient reproduction light detected by the first photodiode and the maximum light amount of ambient reproduction light detected by the second photodiode.

The recording areas are successively formed on the track and have a multiplexing angle that is offset by a constant angle.

The incident condition of the reference light is any one of an incident angle of the reference light or a tilting angle of the storage medium.

An optical expander extending the signal light; A spatial light modulator for loading data into the expanded signal light, and a shielding shutter to block an optical path of the signal light when optical information is reproduced; And a Fourier transform lens for Fourier transforming the signal light to enter the storage medium.

In the optical information reproducing method according to the present invention for achieving the above object, in a optical information storage medium having a plurality of recording areas adjacent to each other in the track direction, a specific recording area and a pair of other recording areas adjacent to the specific recording area. Injecting reference light to include; Separating the reproduction light reproduced in the specific recording area by the reference light and the pair of ambient reproduction light reproduced in a pair of other recording areas adjacent to the specific recording area; And detecting the intensity of the pair of ambient reproduction light to be separated, and comparing the detected intensity of the ambient reproduction light to set the incident condition of the reference light.

The incident condition of the reference light sets the incident condition of the reference light based on a time difference at which the maximum amount of light of the pair of ambient reproduction lights is generated.

The time difference at which the maximum light amount of the pair of ambient reproduction lights is generated is calculated by the following equations.

delete

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는 주변재생광의 광량을 감지하는 서브포토다이오드에서 감지되는 광량, 상기

는 하나의 기록영역이 하나의 포토다이오드를 지나가는 시간.remind

Is the amount of light detected by the subphotodiode sensing the amount of ambient reproduction light, the

Is the time that one recording area passes through one photodiode.

The recording areas are successively formed on the track and have a multiplexing angle which is offset by a constant angle.

The incident condition of the reference light is any one of an incident angle of the reference light or a tilting angle of the storage medium.

Hereinafter, an optical information processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

In the description of the present invention, the names of the elements defined are defined in consideration of functions in the present invention, and should not be understood as meanings that limit the technical elements of the present invention. May be referred to by other names in the art. In addition, the code added to each component is described for convenience of description, and the contents shown in the drawings in which these codes are described do not limit each component to the range in the drawing.

1 is a block diagram showing an optical information processing apparatus according to the present invention, Figure 2 is a block diagram showing a digital signal processor of the optical information processing apparatus according to the present invention.

As illustrated, the optical information processing apparatus 100 according to the present invention includes a light source 110 that emits light L and a light L that is emitted from the light source 110. The polarized light splitter 120 and the reference light R separated by the polarized light splitter 120 are converted into the storage medium D and incident to a plurality of optical information recording areas formed in the track direction of the storage medium. The reference optical optical system 130 and the signal optical system 140 which loads data into the signal light S separated by the polarized light splitter 120 and enters the storage medium D, and the storage medium D by the reference light R. A reading unit for detecting the reproduction light P1 to be reproduced in the optical information recording area of the < RTI ID = 0.0 > 150 and servo control of the reference light R through the reproduction light P1 and the ambient reproduction light P2 detected by the reading unit 150. And a neutralization control unit 160.

First, the present invention is a servo for reproducing optical information while irradiating light to a plurality of optical information recording areas and reproducing optical information using a plurality of reproduction light (P1, P2) reproduced in the plurality of optical information recording areas. Control is possible. Hereinafter, the light reproduced in the recording area in which the optical information is stored is called the reproduction light P1, and the light reproduced in the other recording areas D2 and D3 adjacent to the recording area in which the optical information is stored is called the peripheral reproduction light P2. .

The light source 110 generates light L having a predetermined wavelength, and the light L generated by the light source 110 is a parallel light beam, which is a plane wave-type laser light having excellent coherent. It is preferred, for example, to have the wavelength required for holographic data storage.

The polarized light splitter 120 uses the light L generated by the light source 110 as a reference light of the P polarization component for reproducing the optical information and a signal light of the S polarization component to which data is stored when the optical information is stored. The polarization splitting surface is formed by repeatedly depositing two or more kinds of materials having different refractive indices. The polarization splitting surface transmits the signal light S, The reference light R serves to reflect.

In addition, a separate light adjusting member (not shown) may be provided in the optical paths of the reference light R and the signal light S separated from the polarized light splitter 120 to adjust the characteristics of each light. The light adjusting member may be provided as a polarizing plate or a photosensitive filter. The light adjusting member is installed when precise control of the reference light and the signal light S is required, and the characteristics of the reference light R and the signal light S are guaranteed. If not, it may not be installed.

The reference optical system 130 is for injecting the reference light R separated by the polarized light splitter 120 into the optical information recording area of the storage medium D. The plurality of reflections for switching the optical path of the reference light R Mirrors 132 and a plurality of focus lenses 134 for imaging the reference light R reflected by the reflection mirrors 132 on the storage medium D. Here, the plurality of reflection mirrors 132 may further include a galvano mirror 136 for multiplexing the reference light (R).

The signal optical optical system 140 is for loading data into the signal light S separated from the polarized light splitter 120, and includes an optical expander 142 extending the signal light S separated from the polarized light splitter 120. A spatial light modulator 144 for loading data into the extended signal light S, a shielding shutter 146 for blocking an optical path of the signal light S during reproduction of optical information, and a signal light S having data loaded thereon Is provided with a Fourier transform lens 148 for forming an image on the storage medium (D).

 Here, the optical expander 142 may combine the plurality of lenses to form a signal light S separated by the polarized light splitter 120 to have a light area suitable for loading data in the spatial light modulator 144. Can be.

The spatial light modulator 144 is a typical TFT LC (thin film transistor liquid crystal) of an active matrix, a super twisted nematic liquid crystal (STN LC) of a passive matrix, a ferroelectric LC, a polymer dispersion (PDLC). Liquid crystal), and a transmissive optical modulator such as plasma address liquid crystal (PALC) or a reflective optical modulator including a separate reflective optical system and a digital micro-mirror device.

Further, the shielding shutter 146 blocks the path of the signal light S when the optical information is reproduced, and when the optical information is recorded, the optical path of the signal light S is opened to form the optical path of the signal light S. At the same time, it plays a role of preventing unnecessary light, other than the signal light S, from entering the optical path of the signal light S.

Meanwhile, a plurality of lenses 149 are formed between the optical expander 142, the spatial light modulator 144, and the shielding shutter 146 to form an optical path of the signal light S. Such a lens 149 may be formed by a combination of various design changes, detailed description thereof will be omitted.

The reading unit 150 records the reproduction light P1 reproduced in the optical information recording area of the storage medium D by the reference light R and other optical information adjacent to the optical information recording area by the reference light R. This is for reading the ambient reproduction light P2 reproduced in the areas D2 and D3.

The readout unit 150 includes a reproduction light splitter 151 through which all reproduction light P1 reproduced in the storage medium D passes, and a λ / 4 wave plate for changing the polarization direction of the reproduction light P1. 153 and the reproduction light filter which passes the reproduction light P1 reproduced in the optical information recording area among the reproduction light P1 and reflects the ambient reproduction light P2 reproduced in the adjacent recording areas D2 and D3. 154, a regenerated light detector 157 for detecting regenerated light that has passed through the regenerated light filter 154, and an ambient light detector for detecting ambient regenerated light P2 reflected by the regenerated light filter 154 ( 158 and a plurality of lenses 159 for focusing the reproduction light P1 and the ambient reproduction light P2.

Here, the regenerated light filter 154 has a through hole 154a through which only the regenerated light P1 passes, and a regenerated light P1 is formed on one surface of the regenerated light P1 and the surrounding regenerated light P2. A reflective surface 154b is formed that reflects the ambient reproduction light P2 having a focal length different from that in the direction opposite to the traveling direction.

The focal length is located at the tip of the regeneration light filter 154 at the through hole 154a of the regeneration light filter 154 so that only the regeneration light P1 directed to the regeneration light filter 154 passes through the regeneration light filter 154. The focus lens 155 is provided, and a Fourier transform lens 156 is provided at the rear end of the regenerated light filter 154 to inverse Fourier transform the regenerated light passing through the through hole 154a of the regenerated light filter 154. .

Further, the lambda / 4 wavelength plate 153 is provided on the optical path of the reproduction light P1 passing through the reproduction light splitter 151 to invert the phase of the ambient reproduction light P2 reflected by the reproduction light filter 154. For this purpose, the regenerated light P1 and the surrounding regenerated light P2 of the P polarized light component reproduced in the storage medium D are converted into circularly polarized light components while passing through the λ / 4 wavelength plate 153, and the regenerated light filter The ambient reproduction light P2 reflected by 154 passes through the lambda / 4 wavelength plate 153 again and is converted into the S polarization component.

On the other hand, the reproduction light splitter 151, the respective reproduction light (P1) to be reproduced in the storage medium (D) is incident to the reproduction light filter 154, the ambient reproduction light (reflected by the reproduction light filter 154 ( Serves to direct P2) to the ambient photodetector 158.

The reproduction light splitter 151 may include two or more kinds of materials having different refractive indices so as to be reflected by the reproduction light filter 154 and reflect the ambient reproduction light P2 whose phase is changed by the λ / 4 wave plate 153. It has a polarization splitting surface of a structure repeatedly deposited. The polarization split surface passes the regenerated light P1 and the surrounding regenerated light P2 of the P polarized light component, is reflected by the regenerated light filter 154, and reciprocally passes through the λ / 4 wavelength plate 153 to form the S polarized light component. The ambient regenerated light P2 switched to is refracted.

In addition, the reproduction light detector 157 detects the reproduction light P1 which is passed through the reproduction light filter 154 and is inversely Fourier transformed, and includes a charge-coupled device (CCD) having a high density pixel array, An image sensing device such as a complementary metal-oxide semiconductor (CMOS) may be employed.

In addition, the ambient light detector 158 is used to detect the ambient reproduction light P2 reflected by the reproduction light filter 154 and refracted by the reproduction light splitter 151, and detected by the ambient light detector 158. The tilting servo of the galvanometer mirror 136 or the storage medium D for injecting the reference light R is controlled by comparing the light amount of the reproduction light P2.

The ambient light detector 158 includes a pair of adjacent photo diodes PD1 and PD2, and each of the photodiodes PD1 and PD2 has a set of sub-elements for detecting the ambient regeneration light P2. It consists of photodiodes PD1a, PD2b, PD1c, PD2d. Further, the pair of photodiodes PD1 and PD2 are formed in a direction corresponding to the track direction formed by the optical information recording area of the storage medium D.

The multiplexing controller 160 controls the multiplexing angle of the galvano mirror 136 by reading the light amount of the ambient reproducing light P2 when the optical information is reproduced, and as shown in FIG. 2, the ambient light detector 158. Control of the galvano mirror 136 by reading the adjusted signal and the anti-aliasing filter 162 that adjusts the signal detected by the power meter 161. And a digital signal processor (DSP) 163 for generating a signal for the digital signal processor (DSP).

Here, the digital signal processor 163 includes an AD converter 164 for converting a signal detected by the power meter 161, a low pass filter 165 for removing an unnecessary signal from a signal changed by the AD converter 164, and The angle error calculator 166 which analyzes the signal changed by the AD converter 164 to determine the servo state of the reference light R, and the galvano mirror 136 according to the calculated servo state of the reference light R. A controller 167 for controlling is provided.

On the other hand, the storage medium (D) is formed with a recording area for storing the holographic optical information by angular multiplexing, a plurality of recording areas are formed on an extended track, each recording area formed on the track is formed on an adjacent track Optical information is recorded by reference light having different offset angles with respect to the recording area. Such optical information may be stored by the above-mentioned optical information processing apparatus or previously stored by another optical information processing apparatus.

In addition, the storage medium (D) may be a kind of photopolymers (photopolymers). Such a storage medium (D) may be, for example, the product name "HRR-660" manufactured by Dupont or the product name "ULSH-500" manufactured by Aprilis, or polymethylmethacrylate (PMMA). have. And other kinds of photopolymer may be adopted, and may be formed in the form of a disk.

Hereinafter, the optical information recording and reproducing process of the optical information processing apparatus according to the present invention will be described. Each element mentioned below should be understood with reference to the above description and drawings.

First, recording of optical information will be described. Light L is emitted from the light source 110 for recording the optical information. The light L emitted therefrom is separated into the reference light R and the signal light S by the polarized light splitter 120. Here, the separated reference light (R) and the signal light (S) can be adjusted its characteristics (for example, intensity, uniformity, polarization, etc.) by a light control member (not shown).

The signal light S separated from the polarized light splitter 120 is expanded by the optical expander 142 so that the data is loaded by the spatial light modulator 144, and the storage medium is loaded by the Fourier transform lens 148. It enters into D) (step S110).

In addition, the reference light R separated by the polarized light splitter 120 is refracted by the reflection mirror 132 and the galvano mirror 136 and is incident on the storage medium D by the focus lens 134. Here, the incident reference light R is angled and incident on the specific recording area formed on the track by the galvano mirror 136 and the respective recording areas D2 and D3 adjacent to the specific recording area (step S120). ).

As the reference light (R) and the signal light (S) intersect in the storage medium (D), a holographic interference pattern is formed in the storage medium (D), and the holographic interference pattern is used to reproduce data for reproducing the storage medium (D). do.

Meanwhile, the recording state of the optical information recording area stored in the storage medium in the above-described process will be described. In the storage medium D, a plurality of tracks of different diameters are formed in a short or extended state, and in each track, a plurality of optical information recording areas are formed in a state of maintaining a constant interval by a kind of shift multiplexing. In addition, each recording area formed in the track stores optical information in the recording area by a kind of angle multiplexing while the reference light R is offset by the galvano mirror 136 at a predetermined angle.

That is, a plurality of recording areas formed in a particular track are formed at regular intervals by shift multiplexing, and each recording area is recorded by angle multiplexing at a predetermined angle.

On the other hand, the offset angle difference of each recording area may be set according to the angle selectivity curve. In other words, if the difference between the offset angles is too large, the intensity of light reproduced together in the tracks around the selected track is too small, and if the difference between the offset angles is too small, angular multiplexing is difficult.

Hereinafter, an optical information reproducing process of the optical information processing apparatus will be described with reference to the accompanying drawings. 3 is a flowchart showing optical information reproduction by the optical information processing apparatus according to the present invention.

First, light L is emitted from the light source 110 for recording optical information. The light L emitted therefrom is separated into the reference light R and the signal light S by the polarized light splitter 120.

Meanwhile, the signal path S separated from the polarized light splitter 120 is blocked by the shielding shutter, and the reference light R separated from the polarized light splitter 120 is reflected mirror 132 and the galvano mirror. It is refracted by 136 and is incident on the storage medium D by the focus lens 134. Here, the incident reference light R is incident in an extended state to include the specific recording area and the other recording areas D2 and D3 adjacent to the specific recording area (step S210).

Thus, the reproduction light P1 is formed in the specific recording area of the storage medium D, and the peripheral reproduction light P2 is formed in the other recording areas D2 and D3 adjacent to the specific recording area. On the other hand, the regenerated light P1 and the ambient regenerated light P2 formed by the incident of the reference light R are reproduced in a state having the P polarized light component which is the polarization component of the reference light R.

When the regenerated light P1 and the surrounding regenerated light P2 thus reproduced pass through the regenerated light separator and pass the λ / 4 wavelength plate 153, the circularly polarized light is converted, and then the regenerated light P1 is converted into circularly polarized light. Is focused on the through-hole of the reproduction light filter 154 by the focus lens 155 and passes through the reproduction light filter 154, and the ambient reproduction light P2 is a reflection surface 154b formed in the reproduction light filter 154. Is reflected in the direction opposite to the optical path (step S220).

Here, the regenerated light P1 passing through the regenerated light filter 154 is inverse Fourier-transformed through the Fourier transform lens 156 and is incident to the regenerated light detector 157 to receive light information by the regenerated light detector 157. Is read.

On the other hand, the ambient regenerated light P2 reflected by the regenerated light filter 154 is converted to S-polarized light while passing through the λ / 4 wavelength plate 153 again. The ambient reproduction light P2 converted to S polarization is refracted by the reproduction light splitter 151 and incident to the ambient light detector 158, and the light intensity is detected by the ambient light detector 158.

The light intensity of the ambient reproduction light P2 detected by the ambient light detector 158 is used as data for tilt servo control of the reference light R and the storage medium D. The tilt servo control inputs the multiplexing angle of the galvano mirror 136 as a set value to enter the reference light R into the storage medium D, and the ambient regenerated light P2 to be reproduced is input to the ambient light detector 158. Is measured.

Since the measured intensity of the ambient reproduction light P2 has a difference greater than or equal to a predetermined size by the multiplexing controller 160, there is a problem in the multiplexing angle of the galvano mirror 136 and the tilting state of the storage medium D. In operation S230, the multiplexing angle of the galvanomirror 136 and the tilting state of the storage medium D may be corrected according to the intensity and the difference of the intensity of the ambient reproduction light P2.

Here, the step of correcting the multiplexing angle of the galvano mirror 136 and the tilting state of the storage medium D according to the intensity and the difference of the intensity of the ambient reproduction light P2 will be described in detail with reference to the accompanying drawings.

4 is a simplified diagram showing an ideal state of light detected by an ambient light detector when reproducing optical information in the optical information processing apparatus according to the present invention, and FIG. 5 is a view illustrating reproducing optical information in the optical information processing apparatus according to the present invention. Figure 6 is a simplified diagram showing the actual state of the light detected by the ambient light detector, Figure 6 is a graph showing the change in the amount of light according to the time change of the ambient reproduction light detected by the ambient light detector shown in Figure 5, Figure 7 is the present invention Is a graph for compensating for time delay of ambient reproduction light detected by an ambient light detector in the optical information processing apparatus according to the present invention.

4 shows an ideal arrangement of the ambient regenerated light P2 and the ambient light detector 158. However, this state indicates that the optical information recorded in the recording area of the storage medium D is formed in the most ideal state, and the recording area of the track adjacent to the recording area is linearly matched to the track to be reproduced. .

In this state, the servo error of the reference light R may be calculated by Equation 1 below according to the amount of light detected by each of the subphotodiodes PD1a, PD2b, PD1c, and PD2d.

[Equation 1]

,

,

,

는 각 서브포토다이오드(PD1a, PD2b, PD1c, PD2d)에서 감지되는 광량을 나타낸다. here

,

,

,

Denotes the amount of light detected in each subphotodiode PD1a, PD2b, PD1c, PD2d.

However, in the actual storage medium D, the recording area of the track adjacent to the recording area of the track to be reproduced as shown in FIG. 5 by the distance between the recording areas formed on the track and the diameter of each track, etc. is detected by the ambient light detector. The photodiode PD1, PD2 of 158 is detected in a state shifted.

FIG. 6 is a graph showing the amount of ambient reproduction light P2 detected by each photodiode PD1 and PD2 in the state shown in FIG. 5, and is detected by a pair of photodiodes PD1 and PD2. It can be seen that the amount of light is generated with a predetermined time difference depending on the state of the track. Accordingly, even in a normal angle servo state of the reference light R, a servo error may be detected according to a difference in light quantity.

Therefore, the amount of light of the peripheral reproduction light P2 detected by the subphotodiodes PD1a, PD1b, PD2c, and PD2d of the photodiodes PD1 and PD2 is determined based on the time difference generated according to the state of the track. It should be calculated. This servo error can be calculated by the following [Equation 2].

,[Equation 2]

,

[Formula 2]

와,

Wow,

와,

Wow,

를 만족하여야 한다.

Must satisfy

는 각 서브포토다이오드(PD1a, PD2b, PD1c, PD2d)에서 감지되는 광량을 나타내며,

는 하나의 기록영역이 하나의 포토다이오드(PD1 또는 PD2)를 지나가는 시간이다.here,

Denotes the amount of light detected in each subphotodiode PD1a, PD2b, PD1c, PD2d,

Is the time at which one recording area passes one photodiode PD1 or PD2.

는, 도 7에 도시된 바와 같은 그래프에 의해 산출되어 질수 있다. 이러한

는 각 포토다이오드(PD1, PD2)에 의해 측정되는 광량의 변화에 따른 +방향으로 증가되는 기울기와, -방향으로 감소되는 기울기에 따른 시간의 합으로 감지되는 광량의 노이즈 등을 고려하여 감지되는 값의 평균에 대하여 85%~95% 이내로 한다.On the other hand, of the formula [2]

May be calculated by a graph as shown in FIG. 7. Such

Is a value detected in consideration of the amount of light detected as a sum of time according to a change in the amount of light measured by each photodiode PD1 and PD2 and the amount of time due to the decrease in the direction of-. The average is within 85% to 95%.

Accordingly, the multiplexing angle of the galvano mirror 136 and the tilting state of the storage medium D are corrected according to the amount of light of the ambient regeneration light P2 detected by each of the photodiodes PD1 and PD2.

Although described in detail with respect to the preferred embodiment of the present invention as described above, those skilled in the art to which the present invention pertains, without departing from the spirit and scope of the invention as defined in the appended claims It will be possible to carry out various modifications of the invention. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

 In addition, as long as the functional similarity and identity thereof, even if the modified embodiment is adopted, it can be seen as an equivalent configuration, and even if the embodiment in which the modified part of the configuration is employed, it can be seen as an equivalent configuration. However, all other modified embodiments include the essential elements of the present invention should be considered to be included in the technical scope of the present invention.

As described above, the optical information processing apparatus and the optical information reproducing method according to the present invention, together with the light reproduced in the selected recording area at the time of reproducing the optical information, the light reproduced in another adjacent recording area in the track of the selected recording area. In comparison with each other, it is possible to enable servo control for reproducing optical information.

Claims (14)

A light source for emitting light; A polarized light splitter that separates the light into a reference light and a signal light; A reference optical system for injecting the reference light to include a specific recording area and a pair of other recording areas adjacent to the specific recording area in an optical information storage medium having a plurality of recording areas adjacent to each other in a track direction; A reading unit detecting reproduction light reproduced in the specific recording area by the reference light and ambient reproduction light reproduced in a pair of recording areas adjacent to the specific recording area; And a multiplexing control unit for controlling the incident condition of the reference light by comparing the amount of light of the pair of ambient reproduction light detected by the reading unit with each other. The method of claim 1, wherein the reading unit, A wave plate for switching the polarization state of the reproduction light and the ambient reproduction light; A regenerated light filter separating the regenerated light passing through the wave plate and the ambient regenerated light and passing the ambient regenerated light to the wave plate; An ambient light detector for detecting the ambient reproduction light passing through the wave plate; And a reproduction light detector for detecting the reproduction light separated by the reproduction light filter. The method of claim 2, wherein the ambient light detector, A first photodiode for detecting ambient reproduction light reproduced in another recording area adjacent to one side of the recording area where the reproduction light is reproduced; And a second photodiode for detecting ambient reproduction light reproduced in another recording area adjacent to the other side of the recording area where the reproduction light is reproduced. And the first and second photodiodes comprise a plurality of subphotodiodes. The method of claim 3, wherein the multiplexing control unit, A power meter for detecting the amount of light detected by the first and second photodiodes; An anti-aliasing filter for adjusting the signal detected by the power meter; And a digital signal processor which reads the signal adjusted by the anti-aliasing filter and controls the incident condition of the reference light. The method of claim 4, wherein the digital signal processor, An AD converter for converting a signal adjusted by the anti-aliasing filter; A low pass filter for removing an unnecessary signal from the signal changed by the AD converter; An angle error calculator for analyzing the signal passing through the low pass filter to determine a servo state of the reference light; And a controller for controlling an incident condition of the reference light according to the servo state of the reference light. The method of claim 4, wherein the digital signal processor, And an incident condition of the reference light according to a generation time difference between the maximum light amount of ambient reproduction light detected by the first photodiode and the maximum light amount of ambient reproduction light detected by the second photodiode. . The recording medium of claim 1, wherein the recording areas include: And a multiplexing angle which is continuously formed on the track and is offset by a predetermined angle. The method of claim 1, wherein the incident condition of the reference light, And an angle of incidence of the reference light or a tilting angle of the storage medium. The method of claim 1, An optical expander extending the signal light; A spatial light modulator for loading data into the expanded signal light, and a shielding shutter to block an optical path of the signal light when optical information is reproduced; And a signal optical system including a Fourier transform lens for Fourier transforming the signal light to enter the storage medium. Injecting reference light in an optical information storage medium having a plurality of recording areas adjacent to each other in a track direction so as to include a specific recording area and a pair of other recording areas adjacent to the specific recording area; Separating the reproduction light reproduced in the specific recording area by the reference light and the pair of ambient reproduction light reproduced in a pair of other recording areas adjacent to the specific recording area; Detecting the intensity of the pair of ambient reproduction light to be separated and comparing the detected intensity of the ambient reproduction light to set the incident condition of the reference light; optical information reproduction method comprising a. The method of claim 10, wherein the incident condition of the reference light, And an incident condition of the reference light is set based on a time difference at which the maximum light amount of the pair of ambient reproduction lights is generated. 12. The optical information reproducing method according to claim 11, wherein the time difference at which the maximum light amount of the pair of ambient reproduction lights is generated is calculated by the following [Formula 1]. [Equation 1]

,

,

,

remind

Is the amount of light detected by the subphotodiode sensing the amount of ambient reproduction light, the

Is the time that one recording area passes through one photodiode. The method of claim 10, wherein the recording areas, And a multiplexing angle which is continuously formed on the track and offset by a constant angle. The method of claim 10, wherein the incident condition of the reference light, And an angle of incidence of the reference light or a tilting angle of the storage medium.

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