KR100825640B1 - Optical information playback device and playback method - Google Patents

Abstract

An optical information reproducing apparatus of the present invention comprises a light source, a first detection unit for detecting reproduction light of a recording area selected from an optical system that provides a path to the light provided by the light source and enters a storage medium and reproduction light reproduced from the storage medium. And the reproduction light reproduced from the storage medium into reproduction light of the selected recording area and adjacent reproduction light reproduced from the adjacent recording area adjacent to the recording area to pass the reproduction light of the selected recording area, and the adjacent reproduction light A second detection unit included in the optical separation member for shielding and the optical separation member to detect optical information of the adjacent reproduction light, and optical information of the adjacent reproduction light detected by the second detection unit to receive a tracking position and determine the tracking position The optical information processing apparatus according to the present invention comprises a recording area in which reproduction light is selected. The structure of the optical information reproducing apparatus is simplified by using an optical separation member that separates the reproduction light and the adjacent reproduction light and detects the optical information of the adjacent reproduction light, and detects the reproduction light required for tracking control directly from the optical separation member. Accurate light information can be obtained.

Tracking, playback device, optical information

Description

Optical information reproducing apparatus and reproducing method

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

FIG. 2 is a schematic view showing the optical separation member shown in FIG. 1.

3A is a simplified diagram showing a regenerated light having a correct tracking position incident on the optical separation member and the second detection unit.

3B is a simplified diagram illustrating a case where the position of the second detection unit and the reproduction light are shifted due to the rotation of the storage medium.

4 is a graph showing the amount of light detection changed according to the rotation of the optical information storage medium when the tracking position is correct.

FIG. 5A is a simplified diagram showing the regenerated light and the second detection unit located above the tracking normal position incident on the optical separation member.

FIG. 5B is a simplified diagram illustrating a case in which the reproducing light incident on the optical separation member is located higher than the tracking position of FIG. 5A and thus the tracking position is deviated to the maximum.

FIG. 6 is a graph showing light quantity values detected in the first detection area and the second detection area when the track position moves from the normal position to the upper track.

FIG. 7 is a graph illustrating a change in difference between light quantity values detected in the first and second detection areas of FIG. 6.

8 is a simplified diagram showing a second detector that detects optical information of adjacent reproduction light by using four light detection areas.

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

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

100: light source 230: optical separation member

240: second detector 300: controller

310: control unit

The present invention relates to an optical information reproducing apparatus and a reproducing method, and more particularly, to an optical information reproducing apparatus and a reproducing method having an optical separation member for separating the regenerated light emitted when the optical information is reproduced to detect the optical information.

In modern society, with the development of the multimedia and telecommunications industry, there is an increasing demand for the production technology of the storage medium capable of storing high capacity information and the information processing technology that can accommodate the data processing speed. Among the technologies attracting attention according to these demands, optical information processing technology is applied to integrated optical, optical computer, optical memory, optical exchange, etc., and active research is being made.

Particularly, the holographic technology of the optical information processing technology is a three-dimensional storage technology that overcomes the limitations of two-dimensional storage, and a signal light containing data information and a reference light intersecting the signal light to generate an interference pattern on the storage medium are incident on the storage medium. Record the optical information. In addition, holographic technology can record data in units of pages, reproduce data in units of bits, and store multiple data by irradiating various angles at one beam spot to increase recording density.

Multiplexing methods include angle multiplexing, phase-code multiplexing, wavelength multiplexing, shift multiplexing, fractal multiplexing, and peristrophic multiplexing. Multiplexing), polytopic multiplexing, and the like.

In the case of optical information recorded using this multiplexing method, it is difficult to irradiate the reference light only to the recording area to be recorded and reproduced in order to increase the recording density. Can be recycled. Since the optical information of the adjacent recording areas becomes a noise component, the reproduction efficiency of the optical information to be detected is reduced. Prior art for blocking noise components include "Progress of the Developement of High Performance Removable Storage at InPhage Technologies for Application to Archival Storage" of US Patent Publication 2004-0179251. In the case of the above-mentioned patent, reproduction light of the selected recording area is passed, and adjacent reproduction light reproduced from the adjacent recording area located adjacent to the selected recording area is shielded. In addition, tracking position control is required in order to precisely irradiate the reference light to the selected recording area to detect the correct optical information. As a related art, a tracking control method of the holographic information storage medium of Patent Publication No. 10-2006-0068464 and Device, image capture method and device. The disclosed patent controls the tracking position by converting the light reproduced from the storage medium into an electrical signal in the photodetector.

Shielding of adjacent reproduction light reproduced in the adjacent recording area located adjacent to the selected recording area and accurate tracking position control are important for detecting correct optical information. However, since most optical information reproducing apparatuses have a separate light detecting unit for detecting the optical information necessary for controlling the shielding means and the tracking position of the adjacent reproduction light, there is a problem in that the configuration 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 reproduce reproduction light emitted during optical information reproduction in a selected recording area and adjacent reproduction light reproduced in an adjacent recording area adjacent to the selected recording area. The present invention relates to an optical information reproducing apparatus and a reproducing method, comprising: an optical separation member for separating optical information of adjacent reproducing light;

An optical information reproducing apparatus according to the present invention for achieving the above object comprises a light source, an optical system that provides a path to the light provided by the light source and enters the storage medium, and a recording area selected from the reproduction light reproduced from the storage medium. A first detecting unit for detecting the reproduction light, and separating the reproduction light reproduced from the storage medium into reproduction light of the selected recording area and adjacent reproduction light reproduced from the adjacent recording area adjacent to the recording area. A light separating member for shielding the adjacent reproduction light, a second detection unit included in the light separation member to detect optical information of the adjacent reproduction light, and optical information of the adjacent reproduction light detected by the second detection unit And a control unit for checking the tracking position and controlling the tracking position.

The controller may further include an adjusting unit configured to adjust the tracking position according to the tracking position analysis of the controller.

The optical separation member may have a hole for passing the reproduction light of the selected recording area.

The second detector may be formed of a photodiode for detecting the amount of light.

The second detection unit may include a light detection area divided into at least two divisions, and the photodiode may be separately provided in each detection area.

The optical information reproducing method according to the present invention for achieving the above object comprises the steps of injecting the light emitted from the light source into the storage medium, the reproduction of the recording area and the adjacent recording area selected by the light incident on the storage medium; Outputting adjacent reproduction light, the reproduction light of the selected recording area reaches the first detection unit, and the adjacent reproduction light is shielded by an optical separation member, and optical information of the adjacent reproduction light together with shielding of the adjacent reproduction light Detecting the tracking state according to the detected optical information of the adjacent reproduction light, and adjusting the tracking position according to the analyzed optical information of the adjacent reproduction light.

The optical information of the adjacent reproduction light may be an amount of light.

The light quantity analyzing step may control the tracking position by dividing and detecting one adjacent reproduction light, and comparing the divided detected light amounts.

Hereinafter, an optical information reproducing apparatus and a reproducing method according to an embodiment of the present invention will be described with reference to the drawings.

1 is a schematic diagram showing an optical information reproducing apparatus according to an embodiment of the present invention. As shown, the optical information reproducing apparatus includes a light source 100. It also includes a reflecting mirror 110 for injecting light provided from the light source 100 to the storage medium. The reflection mirror 110 may use a galvano mirror that is easy to adjust the angle when the optical information is reproduced by using the angle multiplexing method on the storage medium 120.

The light incident on the storage medium 120 by the reflection mirror 110 generates an interference pattern and diffraction to generate reproduction light, and a first lens 210 for traveling reproduction light in parallel in a traveling direction of the generated reproduction light. A second lens 220 is provided to focus the reproduced light passing through the first lens 210 on the light separation member 230.

Subsequently, the reproduction light passing through the first lens 210 and the second lens 220 is separated into the reproduction light of the selected recording area and the adjacent reproduction light reproduced from the adjacent recording area adjacent to the selected recording area to reproduce the selected recording area. The light separating member 230 passes through the light and shields the adjacent reproduction light. In addition, the optical separation member 230 may include a second detector 240 for detecting optical information of adjacent reproduction light, and a photodiode as a photodetector may be used as the second detector 240.

The second detection unit 240 has a light detection area corresponding to a size capable of detecting the optical information reproduced in one adjacent recording area of the adjacent reproduction light. The optical information of the adjacent reproduction light detected by the second detection unit 240 is transmitted to the control unit 300, and the current tracking state is determined according to the optical information. Herein, the light information may mean a light amount.

On the other hand, the reproduction light of the selected recording area passing through the center hole of the optical separation member 230 passes through the Fourier transform lens 250 to proceed to the first detection unit 400 and the optical information is detected by the first detection unit 400. do. CCD and CMOS may be used as the first detector 400.

FIG. 2 is a schematic view showing the optical separation member shown in FIG. 1.

The optical separation member 230 has a plate shape, and a hole 231 is formed at the center of the optical separation member 230 so that the reproduction light of the selected recording area among the reproduction light can pass therethrough. The remaining portion except for the hole 231 is made of a shielding material so that adjacent reproduction light reproduced in an adjacent recording area adjacent to the selected recording area is shielded. In addition, a second detector 240 for detecting optical information of shielded adjacent reproduction light is provided on the upper surface of the optical separation member 230.

The second detection unit 240 detects adjacent reproduction light of at least one or more adjacent recording areas among the shielded adjacent reproduction light, and detects adjacent reproduction light reproduced in the adjacent recording area. Detection area 242. The optical information of the adjacent reproducing light detected in the photodetection area of the second detection unit 240, that is, the amount of light is transmitted to the control unit 300 to determine the tracking position, and the position of the optical system 200 is adjusted by the control unit 310. The tracking position can be adjusted. The adjusting unit 310 may use a linear actuator.

Hereinafter, the tracking position and the optical information detection will be described.

FIG. 3A is a simplified diagram showing a regenerated light having a correct tracking position incident on the optical separation member and the second detector, and FIG. 3B is a simplified diagram showing a case where the positions of the second detector and the regenerated light are shifted due to the rotation of the storage medium.

As shown in FIG. 3A, the optical separation member 230 includes a second detection unit 240. The second detector 240 has a light detection area corresponding to a size capable of fully detecting one recording area of incident incident reproduction light. In this case, the light detection area may be divided into a first detection area 241 and a second detection area 242 and may be configured as a photodiode capable of sensing the amount of light.

When the tracking position is correct as shown in Fig. 3A, adjacent reproduction light reproduced in the adjacent recording area around the selected recording area among the reproduction light can be detected accurately. At this time, one-half light amount of the adjacent reproduction light reproduced in one adjacent recording area is detected in the first detection area 241 of the two divided photodetection areas, and the one adjacent recording area in the second detection area 242. The amount of 1/2 light of the regenerated light reproduced at is detected so that the first detection area 241 and the second detection area 242 have the same light amount value.

When the storage medium 120 rotates in the counterclockwise direction as shown in FIG. 3B, the recording area recorded on the storage medium 120 is also moved to the left side, and thus the reproduction light reproduced in the recording area is also moved to the left side. Accordingly, as shown in FIG. 3B, when the optical information storage medium 120 rotates by a shorter distance than one recording area, a part of the adjacent reproduction light reproduced in the recording area and a portion of the adjacent reproduction light reproduced in the neighboring recording area are the second detection unit ( You can see it in position 240). At this time, the amount of light detected in the photodetection area due to the interval between two adjacent reproduction light has a value smaller than the light amount value of FIG. 3A.

However, since the tracking position is correct, some of the adjacent regenerated light entering the position of the second detection unit 240 is divided in exactly half, so that the light amount of the first detection region 241 and the second detection region 242 is equal to each other.

4 is a graph showing the amount of light detection changed according to the rotation of the optical information storage medium when the tracking position is correct. In the graph shown in FIG. 4, the X axis represents time and the Y axis represents light quantity.

When the reference light is incident on the storage medium 120 having the optical information recording area, the reproduction light of the selected recording area and the adjacent reproduction light of the adjacent recording area are simultaneously emitted. Thereafter, optical information of adjacent reproduction light is detected in the first detection area 241 and the second detection area 242 of the second detection unit 240. At this time, the control unit 300 determines whether the light amount values detected in the first detection area 241 and the second detection area 242 are equal to each other. If not, the control unit 310 controls the control unit 310 to adjust the tracking position. . In addition, when the amount of light detected in the first detection area 241 and the second detection area 242 is the same, whether the adjacent reproduction light is exactly positioned in the second detection unit 240 or the adjacent reproduction light adjacent to one adjacent reproduction light. It is determined whether the second detection unit 240 is located in the light quantity value.

If the tracking position is continuously adjusted, the storage medium 120 rotates, and the amount of light changes as shown in the graph of FIG. 4. The amount of light detected in the first detection area 241 and the second detection area 242 is increased and decelerated at regular intervals. That is, the amount of light when the reproduction light reproduced in one recording area is exactly entered into the light detection area has the maximum value, and is reproduced by rotating the reproduction light reproduced in one recording area and another recording area adjacent to one recording area. The amount of light has the minimum value when the light detecting region is located between the reproduced light beams.

FIG. 5A is a simplified diagram showing the regenerated light and the light detecting member positioned above the tracking normal position incident on the light separating member.

As shown in FIG. 5A, when the tracking position is located above the normal position, the central portion of the reproduced light reproduced in one recording area is located in the first detection area 241 so that the amount of light detected is large. It is confirmed that a part of the reproduction light reproduced in the recording area and a part of the reproduction light reproduced in the recording area located on the next track are located in the second detection area 242 so that the amount of light detected is small. In this case, since the tracking position is accurate only when the amount of light detected in the first detection area 241 and the second detection area 242 is the same, the tracking position should be adjusted downward by controlling the adjusting unit 310.

In addition, if the amount of light detected in the second detection area 242 has a value greater than the amount of light detected in the first detection area 241, the tracking position is located below the normal position. Should be.

FIG. 5B is a simplified diagram illustrating a case in which the reproducing light incident on the optical separation member is located higher than the tracking position of FIG. 5A and thus the tracking position is deviated to the maximum.

As shown in FIG. 5B, a track to be detected is located higher than FIG. 5A so that a part of the reproduced light reproduced in the recording area is located in the first detection area 241, and another track is located in the second detection area 242. It can be confirmed that a part of the reproduced light reproduced in the recording area is located and the amount of light detected is the same.

In this case, as in the case of FIG. 3A, the light quantity values detected in the first detection region 241 and the second detection region 242 are the same, but the tracking position is confirmed by checking the tracking position. When the light quantity values are the same in the second detection region 242 and when the light quantity values in the first detection region 241 and the second detection region 242 are the same, it is possible to determine whether the light quantity values are the same.

FIG. 6 is a graph showing light quantity values detected in the first detection area and the second detection area when the track position moves from the normal position to the upper track. The X axis of the graph means time, and the Y axis means light quantity value.

When the reference light is incident on the selected recording area, the reproduction light of the selected recording area and the adjacent reproduction light of the recording area adjacent thereto are emitted, and the first detection area 241 and the second detection area 242 of the second detection unit 240 are emitted. ) Detects the optical information of the adjacent reproduction light. At this time, the current tracking position is determined by comparing the light quantity values detected by the first detection area 241 and the second detection area 242.

As shown in FIG. 6, since the tracking position is correct at the point A where the light quantity values detected in the first detection region 241 and the second detection region 242 are the same and coincide with a predetermined setting value, the storage medium 120 is used. Rotate to detect light information of the selected track. Then, when the detection of the optical information of the selected track is finished, the amount of light detected while moving the position of the track to detect the optical information of another track is as shown in the graph.

After the point A, the amount of light detected in the first detection area 241 is increased than the amount of light detected in the second detection area 242. The center of the adjacent reproduction light reproduced in the adjacent recording area is the first detection area 241. Because it was moved.

Subsequently, when the adjacent reproduction light is further moved upward, only a portion of the center of the adjacent reproduction light is positioned outside the first detection area 241, and a portion of the adjacent reproduction light of another track is positioned in the second detection area 242 so that the first reproduction light is moved. The amount of light detected in the detection area 241 and the second detection area 242 becomes equal. This state is 5b and indicates point B.

Subsequently, the adjacent reproduction light of the other track is moved upwards to detect a light amount value larger than the light amount value detected in the first detection area 241 in the second detection area 242, and the adjacent reproduction light of the other track. If it is moved further upward and positioned exactly in the photodetection area, it has the state of point A again.

FIG. 7 is a graph illustrating a change in difference between light quantity values detected in the first and second detection areas of FIG. 6.

As shown in Fig. 7, the difference value becomes zero at the point A because the light quantity values detected in the first detection area 241 and the second detection area 242 are the same. Afterwards, when the tracking position moves upward, the light amount value detected in the first detection area 241 becomes larger than the light amount value detected in the second detection area 242 and rises as shown in the graph.

The maximum value of the graph shown in FIG. 7 means that the center of the moved adjacent reproduction light is located at the center of the first detection area 241. The center of the adjacent reproduction light is off the center of the first detection area 241. Descends. The minimum value of the graph means that the center of adjacent reproduction light of another track is located at the center of the second detection area 242. Then, when the adjacent reproduction light of another track is moved upward, it is in the same state as point A again.

8 is a simplified diagram showing a second detector that detects optical information of adjacent reproduction light by using four light detection areas.

As shown in FIG. 8, the second detector 240 detects the light information using four light detection areas. That is, two divided second detection units 240 are provided.

The position of the track using the difference in the amount of light detected in the first detection area 241 and the second detection area 242 and the difference in the amount of light detected in the third and second detection areas 243 and 244. Determine.

For example, when light is detected in the first detection area 241 and the second detection area 242, and no light is detected in the third detection area 243 and the fourth detection area 244, this indicates the last track. Can mean. In addition, when light is detected in the third detection area 243 and the fourth detection area 244, and no light is detected in the first detection area 241 and the second detection area 242, this means the first track. can do. This is because the light amount of the previous track is not detected in the first track, and the light amount of the track after that is not detected in the last track.

Therefore, when two or more divided second detection units 240 are used, tracking position determination is more accurate than when one is used, and the first track and the last track can be distinguished.

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

First, the light emitted from the light source 100 is incident to the storage medium 120 (S100). Thereafter, the reproduction light is emitted from the recording area selected by the light incident on the storage medium 120 and the adjacent recording area (S200). The regenerated light of the selected recording area of the emitted regenerated light passes through the hole of the optical separation member 230 to reach the first detection unit 400, and the adjacent regenerated light reproduced in the adjacent recording area is transferred to the optical separation member 230. Incident and shielded (S300). Subsequently, the adjacent regenerated light shielded by the light separation member 230 is detected by the second detection unit 240 included in the light separation member 230 in the light detection area (S400). The current tracking state is analyzed using the detected optical information (S500). The tracking position is adjusted according to the analyzed optical information (S600).

The optical information reproducing apparatus and the reproducing method according to the present invention as described above use the optical information reproducing apparatus by using the optical separation member for separating the reproducing light into the reproducing light and the adjacent reproducing light of the selected recording area and simultaneously detecting the optical information of the adjacent reproducing light. The structure is simplified, and more accurate optical information can be obtained because the regenerated light required for tracking control is detected directly by the optical separation member.

Claims (8)

Light source; An optical system providing a path to the light provided by the light source and allowing the light to enter the storage medium; A first detector for detecting reproduction light of a selected recording area from reproduction light reproduced from the storage medium; The reproduction light reproduced from the storage medium is separated from the reproduction light of the selected recording area and the adjacent reproduction light reproduced from the adjacent recording area adjacent to the recording area to pass the reproduction light of the selected recording area, and the adjacent reproduction light is shielded. Optical separation member to be; A second detector included in the optical separation member to detect optical information of the adjacent reproduction light; And And a control unit configured to receive optical information of the adjacent reproduction light detected by the second detection unit, analyze a tracking position, and control the tracking position. The optical information reproducing apparatus according to claim 1, further comprising an adjusting unit which adjusts the tracking position according to the tracking position analysis of the control unit. The optical information reproducing apparatus according to claim 1, wherein the optical separation member has a hole for passing reproduction light of the selected recording area. The optical information reproducing apparatus according to claim 1, wherein the second detecting unit comprises a photodiode for detecting the amount of light. The optical information reproducing apparatus according to claim 4, wherein the second detection unit comprises a light detection area divided into at least two divisions, and the photodiodes are separately provided in each detection area. Injecting light emitted from the light source into the storage medium; Outputting the reproduction light of the recording area selected by the light incident on the storage medium and the adjacent reproduction light of the adjacent recording area; The reproduction light of the selected recording area reaches the first detection unit, and the adjacent reproduction light is shielded by an optical separation member; Detecting optical information of the adjacent reproduction light in the light detection area of the second detection unit together with shielding of the adjacent reproduction light; Analyzing a tracking state according to the detected optical information of the adjacent reproduction light; And And a tracking position is adjusted according to the analyzed optical information tracking state of the adjacent re-image light. 7. The optical information reproducing method according to claim 6, wherein the optical information of the adjacent reproduction light is an amount of light. The method of claim 6, wherein the analyzing of the tracking state according to the optical information of the adjacent reproduction light comprises dividing and detecting one adjacent reproduction light, and controlling the tracking position by comparing the detected amount of the divided light. Optical information reproduction method.

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