KR20090095788A - Format of optical information recording medium and method of servo control using the same - Google Patents

Abstract

A format of an optical information storage medium and a servo control method using the same capable of recording optical information by using holography are provided to divide optical information storage medium into a unit recording area and perform servo control and addressing operation. A format of an optical information storage medium includes a data region(110) and a servo region(130). The servo region is that the unit record domain(150) along with data area which is formed in data area. The servo region comprises the pattern reflecting the servo light which is income for addressing and servo control. The servo region comprises the division pattern. The division pattern is arranged as the diameter direction of the optical information storage medium between data area and the adjacent data area. The division pattern has the division information of data area. The servo region comprises the location initialization pattern. The location initialization pattern reflects the servo light which is income to the unit record domain for the first time.

Description

Format of optical information recording medium and method of servo control using same {Format of optical information recording medium and method of servo control using the same}

The present invention relates to a format of an optical information storage medium and a servo control method using the same, and more particularly, to a format of an optical information storage medium for recording and reproducing optical information on a storage medium using holography and a servo control method using the same. It is about.

Recently, with the rapid development of the information and computer industry, there is an increasing demand for a storage device capable of satisfying high capacity storage capacity and high speed input / output of data.

Therefore, it is an optical information storage medium capable of high-capacity storage and high-speed input / output of data using optical, and it is a compact disc (CD), a digital versatile disc (DVD), a high-definition DVD (HD-DVD), Blue-ray discs (BDs), holographic digital data storage (HDDS), and the like are in the spotlight.

Among these, an optical information processing device (hereinafter, referred to as an “optical information processing device”) using a holographic digital information storage device separates light emitted from a light source into a reference beam and a signal beam, and Optical information is recorded by an interference fringe generated by crossing signal light in a storage medium of a photorefractive material such as a photopolymer.

In the optical information processing apparatus, a method of multiplexing light is used to increase the recording density of data. Methods of multiplexing light include angular multiplexing, phase-code multiplexing, wavelength multiplexing, and shift multiplexing. Here, the angular multiplexing method is to multiplex by changing the incident angle 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.

In order to reproduce the optical information multiplexed and recorded on the optical information storage medium, the reference light incident upon optical information recording is restored, the reference light is incident on the interference pattern of the optical information storage medium, and the reproduced light is diffracted and reproduced from the interference pattern. Is detected, and optical information is acquired from this reproduced light.

On the other hand, in the conventional ROM type optical disk drive, addressing and data recording are performed using physical reflection patterns such as wobble and pit, and servo control is performed using these reflection patterns.

 In the optical information storage medium using holographic, if a reflective pattern such as a pit or a wobble is engraved in the whole optical information storage medium, such as a ROM type optical disk drive, recording of optical information by the reflection pattern during addressing and servo control And problems affecting reproduction.

Accordingly, an object of the present invention is to provide a format of an optical information storage medium that does not affect recording and reproduction of optical information by a reflection pattern during addressing and servo control using the optical information storage medium using holographic, and using the same. The present invention provides a servo control method.

An optical information storage medium for recording optical information by an interference fringe formed by crossing reference light and a signal light, the optical information storage medium according to an embodiment of the present invention includes a data area in which at least one interference fringe is recorded; And a servo area adjacent to the data area to form a unit recording area together with the data area, and including a pattern for reflecting the incident servo light for addressing and servo control.

The servo area is disposed between the data area adjacent to the radial direction of the optical information storage medium and the data area, and the classification information of the data area is divided from the data area adjacent to the radial direction of the optical information storage medium. The branch may have a division pattern.

The servo area may be disposed between the data area adjacent to the travel direction of the servo light and the data area, and may have a position initialization pattern for initially reflecting the servo light incident on the unit recording area.

The servo region may be disposed between the position initialization pattern and the data region, and may include an address pattern having position information of the data region.

The servo area may include a tracking servo pattern disposed between the address pattern and the data area and having position compensation information of the optical information storage medium.

The optical information storage medium has a track structure, and if the diameter of the interference fringe is equal to the width of the track, the tracking servo pattern is shorted at the center of the track and spaced apart in the travel direction of the servo light. And two position compensation patterns.

The pattern may be formed on the side where the servo light is incident from the recording layer of the optical information storage medium on which the interference fringe is formed.

On the other hand, the data area for recording the optical information in the interference pattern formed by the intersection of the reference light and the signal light, and a unit recording area is formed adjacent to the data area, and the pattern reflecting the incident servo light for addressing and servo control An optical information processing method using a format of an optical information storage medium having a servo area, comprising: injecting servo light into the optical information storage medium to detect the servo light reflected by a position initialization pattern disposed in the servo area A position initialization step of initializing a position of the optical information storage medium; an addressing step of detecting the servo light reflected by an address pattern disposed between the position initialization pattern and the data area to find the data area; and Tracking servo pattern disposed between the address pattern and the data area And a tracking servo control step of detecting the servo light reflected by and performing tracking servo control of the reference light and the signal light.

A data area adjacent in the radial direction of the optical information storage medium and the servo light reflected by a division pattern disposed between the data area and detecting the servo light from the data area adjacent in the radial direction of the optical information storage medium. An area classification step of dividing the data area may be further included.

The optical information storage medium has a track structure, and if the diameter of the interference fringe is equal to the width of the track, the tracking servo pattern is shorted at the center of the track and spaced apart in the travel direction of the servo light. And a second position compensation pattern, wherein the tracking servo control step includes: light intensity of the servo light reflected and detected from the first position compensation pattern and light intensity of the servo light reflected and detected from the second position compensation pattern; The reference light and the signal light may be incident to a position at which a difference value of "0" is detected.

In the format of the optical information storage medium and the servo control method using the same, the optical information storage medium is divided into a unit recording area, and the unit recording area is divided into a data area and a servo area including a reflection pattern. It does not affect recording and reproducing of optical information, and there is an effect that addressing and servo control can be performed.

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

1 is a block diagram showing a part of an optical information processing apparatus using an optical information storage medium according to the present invention. Referring to FIG. 1, although not shown, the optical information processing apparatus 200 crosses the reference light R and the signal light S on the storage medium 100 to form an interference fringe 111, and the optical information storage medium. A recording / reproducing optical system (not shown) for detecting the reproduction light P reproduced from the 100 (hereinafter referred to as a “storage medium”). At this time, the reference light (R) and the signal light (S) may be used a green light (green beam) in response to the photosensitive medium.

The optical information processing apparatus 200 records the optical information by crossing the reference light R and the signal light S in a recording layer (not shown) of the storage medium 100 formed of the photosensitive medium. In this case, a data page divided into on pixels / off pixels is loaded in the signal light S. FIG.

In addition, the optical information processing apparatus 200 causes the reference light R used in recording the optical information to enter the interference fringe 111 and detects the reproduction light P from the interference fringe 111 to thereby reproduce the optical information. .

Meanwhile, the optical information processing apparatus 200 performs servo control to adjust the position of the storage medium 100 and the incident positions of the reference light R and the signal light S before recording and reproducing the optical information. Therefore, the optical information processing apparatus 200 transmits or reflects the servo light SV according to the polarization of the servo light source 210 for providing the servo light SV and the servo light SV provided from the servo light source 210. The polarized light splitter 230, the λ / 4 wave plate 250 for changing the polarization of the servo light SV reflected by the polarized light splitter 230 into circularly polarized light, and the servo light SV are provided in the optical information storage medium 100. A condenser lens 270 for condensing the light is provided. In this case, the servo light SV may preferably be a red beam having a wavelength that does not respond to the photosensitive medium.

The optical information processing apparatus 200 includes a servo light detector 290 so as to detect the servo light SV in a path of the servo light SV that is incident and reflected by the servo light SV to the storage medium 100. The servo light detector 290 may be configured as a photodiode capable of detecting the light intensity of the detected servo light (SV).

The optical information processing apparatus 200 provides the servo light SV of P polarization from the servo light source 210. Servo light SV of P-polarized light is reflected by the polarized light splitter 230 and is changed into circularly polarized light while passing through the λ / 4 wave plate 250. The servo light SV, which is changed into circularly polarized light, is incident on the storage medium 100 by the condenser lens 270. Of the servo light incident on the storage medium 100, the servo light SV incident on each pattern included in the servo region 130 is reflected, and the servo light SV incident on the data area 110 is stored in the storage medium 100. Through).

Servo light (SV) reflected in each pattern of the servo region 130 is changed from circular flat light to S polarized light while passing through the condenser lens 270 and the λ / 4 wave plate 250 and transmitted through the polarized light splitter 230. do. The servo light (SV) transmitted through the polarized light splitter 230 is detected by the servo light detector 290.

Hereinafter, an optical information storage medium according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a perspective view showing an optical information storage medium according to an embodiment of the present invention, and FIG. 3 is a partially enlarged view showing part I shown in FIG. 2 to 3, the storage medium 100 includes a data area 110 and a servo area 130. The data area 110 and the servo area 130 form a unit recording area 150 that divides the recording area of the storage medium 100.

At least one interference pattern 111 in which the reference light R and the signal light S intersect is recorded in the data area 110. Here, the storage medium 100 may be provided in a disk shape having a disc shape and may have a track structure. The width of each track 113 has a track pitch TP corresponding to the diameter of the interference fringe 111.

Meanwhile, the servo region 130 includes a pattern adjacent to the data region 110 to reflect the servo light SV incident for the servo control of the reference light R and the signal light S. Referring to FIG. The pattern may be formed on the side where the servo light SV is incident from a recording layer (not shown) of the storage medium 100 on which the interference fringe 111 is formed.

The servo region 130 includes a division pattern 131, a position initialization pattern 133, an address pattern 135, and a tracking servo pattern 137. Here, in the following description, for convenience of explanation and understanding, in each of the patterns 131, 133, 135, and 137, a pattern for reflecting the servo light SV is called an on pattern, and the servo light is transmitted. It is assumed that the pattern is an off pattern.

The position initialization pattern 133 indicates the start of the data area 110 and controls an encoder of a motor (not shown) that rotates the storage medium 100 so that the rotation speed of the motor, the rotation direction of the motor, and the motor are controlled. Allows you to adjust the initial origin of the.

The position initialization pattern 133 is disposed between the data area 110 adjacent to each other in the track direction and the address pattern 135. In other words, the position initialization pattern 133 is disposed at a position that initially reflects the servo light SV incident through the adjacent data area 110 in the track direction.

The position initialization pattern 133 may have a regular pattern such that the on pattern and the off pattern are mixed to distinguish the address pattern 130 and the tracking servo pattern 137 described below.

For example, the position initialization pattern 133 may have an on pattern and an off pattern at both sides in contact with the on pattern (that is, in contact with the data region 110 adjacent in the track direction and in contact with the address pattern 135). By having a regular pattern filled with, it may be distinguished from the address pattern 135 and the tracking servo pattern 137.

The address pattern 135 has location information of the data area 110. The address pattern 135 is disposed between the position initialization pattern 133 and the tracking servo pattern 137. In the address pattern 135, the on pattern and the off pattern are mixed according to the location information of the data area 110 to represent the location information of the data area 110.

The tracking servo pattern 137 has position compensation information of the reference light and the signal light, and includes first and second position compensation patterns 137a and 137b. The first and second position compensation patterns 137a and 137b are disposed between the address pattern 135 and the data area 110.

The first position compensation pattern 137a is positioned on the address pattern 135 side, one end of which is in contact with the outer circumference of the track 113, and the other end of which is located in the center of the track 113. The second position compensation pattern 137b is spaced apart from the first position compensation pattern 137a and positioned on the data area 110, one end of which is located in the center of the track 113, and the other end of which is located on the inner circumference of the track 113. I touch it.

The first and second position compensation patterns 137a and 137b respectively detect the servo light SVs reflected from the first and second position compensation patterns 137a and 137b and compare the light intensities of the detected servo light SVs. To enable tracking servo control.

Meanwhile, the division pattern 131 is a data area 110 adjacent in the radial direction of the storage medium 100 and a corresponding data area 110 for recording and reproducing optical information (hereinafter referred to as a 'data area'). When the servo light SV is incident at the same time, the data area 110 can be distinguished from the adjacent data area 110.

The division pattern 131 is formed of either an on pattern or an off pattern, and is disposed in a track direction between the adjacent data area 110 and the data area 110. The division pattern 131 is disposed in contact with the outermost track and the innermost track of the data area 110, respectively.

Hereinafter, a servo control method using an optical information storage medium according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a flowchart illustrating a servo control method using an optical information storage medium according to an embodiment of the present invention. Referring to FIG. 4, the servo light SV is incident to the storage medium 100 to search for a reference position for servo control. Since the servo light SV is transmitted through the data area 110, when the servo light SV passes through the data area 110, it is possible to search for a point where the servo light SV is first reflected. That is, the servo light SV is reflected from the position initialization pattern 133 and detected, and the position where the servo light SV corresponding thereto is incident becomes a reference position.

In this way, by using the reference position retrieved by the position initialization pattern 133, it is possible to initialize a motor (not shown) for rotating the storage medium 100, and to control the rotational speed of the motor (not shown) (step ; S11).

Subsequently, as the storage medium 100 is rotated by the rotation of the motor (not shown), the servo light SV passes through the position initialization pattern 133 and enters the address pattern 135. The servo light SV is reflected from the address pattern 135 and detected, and based on the detected servo light SV, position information about the data area 110 may be acquired.

In this way, the servo light SV reflected from the address pattern 135 may be detected to find the corresponding data region 110 (step S13).

Subsequently, when the servo light SV reflected from the address pattern 135 is detected and the corresponding data area 110 is found, the servo light SV tracks 113 to record and reproduce the optical information in the data area 110. Incident). In order to inject the reference light R and the signal light S into the track 113 in the data area 110, tracking servo control by the servo light SV must be preceded.

5A to 5C are graphs showing the light intensity of the servo light reflected and detected in the tracking servo pattern according to the position of the servo light incident on the track of the optical information storage medium according to the embodiment of the present invention.

Here, y indicated in the graphs shown in FIGS. 5A to 5C is light intensity of the servo light SV detected by the servo light detector 290, t is a track movement distance of the servo light SV, and A is a first distance. Servo light SV reflected by the position compensation pattern 137a is detected, and B represents servo light SV reflected by the second position compensation pattern 137b and detected.

Referring to FIG. 5A, when the servo light SV is incident to the outer circumferential side of the track 113, the light intensity of the servo light SV reflected and detected from the first position compensation pattern 137a is detected by the second position compensation pattern. It can be seen that the light intensity of the servo light SV reflected and detected from 137b is greater.

Referring to FIG. 5B, when the servo light SV is correctly incident to the center side of the track 113, the light intensity of the servo light SV reflected and detected from the first position compensation pattern 137a and the second position compensation pattern are detected. It can be seen that the light intensity of the servo light SV reflected and detected from 137b is the same.

Referring to FIG. 5C, when the servo light SV is incident to the inner circumferential side of the track 113, the second position compensation pattern is smaller than the light intensity of the servo light SV that is detected by being reflected from the first position compensation pattern 137a. It can be seen that the light intensity of the servo light SV reflected and detected from 137b is large.

Accordingly, the tracking servo control of the reference light and the signal light can be performed by using the light intensities of the servo light SVs reflected from the first position compensation pattern 137a and the second position compensation pattern 137b. That is, the tracking error signal calculated using the light intensity of the servo light SV reflected and detected from the first position compensation pattern 137a and the second position compensation pattern 137b may be calculated by Equation 1 below. Can be.

Equation 1)

TE = Y _A -Y _B

Here, TE is a tracking error signal, Y _A is the light intensity of the servo light reflected and detected from the first position compensation pattern, and Y _B is the light intensity of the servo light reflected and detected from the second position compensation pattern.

According to the tracking error signal calculated by Equation 1), the light intensity of the servo light SV reflected and detected from the first position compensation pattern 137a is reflected and detected from the second position compensation pattern 137b. Tracking servo control is performed by moving the storage medium 100 to a position at which the difference value of the light intensity of the servo light SV is calculated as "0", or by moving the incident position of the reference light R and the signal light S. Can be done (step S15).

Here, the servo light SV simultaneously moves to the corresponding data area and the data area 110 adjacent in the radial direction of the storage medium 100 for the same reason as vibration of the storage medium 100 due to rotation of a motor (not shown). Can be incident.

In this case, the servo light SV is reflected and detected from the outermost track of the data area 110 and the division pattern 131 disposed in contact with the innermost track, and the reference light R is detected based on the detected servo light SV. And the signal light S may be prevented from entering the adjacent data area 110 and controlled to be incident into the corresponding data area 110.

The identification of the data region 110 from the data region 110 adjacent in the radial direction of the storage medium 100 by the division pattern 131 may be performed at any time before or after the tracking servo control. .

As described above, the optical information storage medium 100 is divided into a unit recording area 150 to store optical information in the data area 110 and has a servo area 130 adjacent to the data area 110. do. Therefore, the addressing and the servo control of each track 113 and the interference fringe 111 can be performed independently for each data area 110, so that recording and reproduction of optical information are not affected.

1 is a block diagram showing a part of an optical information processing apparatus using an optical information storage medium according to the present invention.

2 is a perspective view showing an optical information storage medium according to an embodiment of the present invention.

3 is a partially enlarged view illustrating a portion “I” shown in FIG. 2.

4 is a flowchart illustrating a servo control method using an optical information storage medium according to an embodiment of the present invention.

5A to 5C are graphs showing the light intensity of the servo light reflected and detected in the tracking servo pattern according to the position of the servo light incident on the track of the optical information storage medium according to the embodiment of the present invention.

<Description of Signs of Major Parts of Drawings>

100: optical information storage medium 110: data area

130: servo area 150: unit recording area

Claims (10)

In an optical information storage medium for recording optical information by an interference fringe formed by the intersection of the reference light and the signal light, A data area in which at least one interference fringe is recorded; and And a servo area adjacent to the data area to form a unit recording area together with the data area, the servo area including a pattern reflecting the incident servo light for addressing and servo control. Format of the medium. The method of claim 1, wherein the servo region, A division pattern disposed between the data area adjacent to the radial direction of the optical information storage medium and the data area, the division pattern having division information of the data area from the data area adjacent to the radial direction of the optical information storage medium; Format of the optical information storage medium, characterized in that. The method of claim 1, wherein the servo region, And a position initialization pattern disposed between the data area adjacent to the travel direction of the servo light and the data area and reflecting the servo light incident to the unit recording area for the first time. The method of claim 3, wherein the servo region, And an address pattern disposed between the position initialization pattern and the data area, the address pattern having position information of the data area. The method of claim 4, wherein the servo region, And a tracking servo pattern disposed between the address pattern and the data area, the tracking servo pattern having position compensation information of the optical information storage medium. The method of claim 5, The optical information storage medium has a track structure, and if the diameter of the interference fringe is the same as the width of the track, The tracking servo pattern, And a first and a second position compensation pattern which are shorted at the center of the track and spaced apart in the travel direction of the servo light. The method of claim 1, wherein the pattern is, And a recording layer of the optical information storage medium on which the interference fringe is formed, on the side from which the servo light is incident. And a data area for recording optical information in an interference fringe formed by the intersection of the reference light and the signal light, and a unit recording area adjacent to the data area, the pattern reflecting the incident servo light for addressing and servo control. In the optical information processing method using the format of the optical information storage medium having a servo area, A position initialization step of initializing a position of the optical information storage medium by detecting the servo light reflected by the position initialization pattern disposed in the servo region by injecting the servo light into the optical information storage medium; An addressing step of detecting the servo light reflected by the address pattern disposed between the position initialization pattern and the data area to find the data area; and And a tracking servo control step of detecting the servo light reflected by a tracking servo pattern disposed between the address pattern and the data area and performing tracking servo control of the reference light and the signal light. Servo control method using format of optical information storage medium. The method of claim 8, A data area adjacent in the radial direction of the optical information storage medium and the servo light reflected by a division pattern disposed between the data area and detecting the servo light from the data area adjacent in the radial direction of the optical information storage medium. And an area classification step of dividing the data area. 2. The servo control method using a format of an optical information storage medium. The optical information storage medium of claim 8, wherein the optical information storage medium has a track structure, and if the diameter of the interference fringe is equal to the width of the track, The tracking servo pattern includes a first and second position compensation patterns which are shorted at the center of the track and spaced apart in the traveling direction of the servo light. The tracking servo control step, The reference light and the position where the difference value of the light intensity of the servo light reflected and detected from the first position compensation pattern and the light intensity of the servo light reflected and detected from the second position compensation pattern are detected as "0". A servo control method using a format of an optical information storage medium, characterized in that a signal light is incident.

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