KR100794026B1 - Method for recording optical information, method for detection optical information and apparatus for detection optical information - Google Patents

Abstract

A method for recording optical information, and an optical information detecting method and device are provided to increase recording and reproducing efficiency with respect to the dimension of a data page. A method for recording optical information includes a step of encoding input data at a page unit; a step of mapping data of the encoded page unit at a data area and a frame mark dividing the data area, and demodulating the data of the page unit optically; and a step of loading the demodulated data on a signal beam and storing the demodulated data in a storage medium. A method for detecting optical information includes a step of detecting an image of a data page stored in an optical information storage medium(S10); a step of analyzing distribution of light intensity for the detected image and detecting a standard pixel of a sampling start for the data page(S50); and a step of detecting the data stored at the frame mark of the data page and the data area on the basis of the detected standard pixel(S60).

Description

Optical information recording method, optical information detection method and optical information detection apparatus {Method for recording optical information, method for detection optical information and apparatus for detection optical information}

1 is a simplified diagram showing the configuration of an optical information processing system according to an embodiment of the present invention.

2 is an exemplary view showing an image of a data page provided by a spatial light modulator according to an embodiment of the present invention.

3 is a block diagram illustrating components of an optical information detecting apparatus according to an exemplary embodiment of the present invention.

4 is a flowchart illustrating an operation flow of an optical information detecting apparatus according to an embodiment of the present invention.

5A is a graph illustrating light intensity difference values of columns of an image of a data page according to an exemplary embodiment of the present invention.

5B is a graph illustrating light intensity difference values of rows in an image of a data page according to an exemplary embodiment of the present invention.

The present invention relates to an optical information recording method, an optical information detecting method, and an optical information detecting device. More particularly, the present invention relates to an optical information recording method, an optical information detecting method, and an optical information detecting device for improving the recording density of data. It is about.

In recent years, as the high-speed data communication service and the digital broadcasting service are popularized, the demand for a next-generation data processing system capable of storing and reproducing a large amount of data is rapidly increasing. One of the most attention-producing systems of these next-generation data processing systems is a light processing system using holography, that is, a holographic light processing system.

The holographic optical information processing system crosses a signal beam including data information and a reference beam irradiated from an angle different from the signal beam at a predetermined position of the optical information storage medium, and intersects the interference pattern generated at this time. Store in an information storage medium. In addition, when the stored data information is reproduced, only the reference light is irradiated to the stored interference pattern, and original data is restored by using a diffraction image generated by the interference pattern.

Such a holographic optical information processing system can store data at the same position of an optical information storage medium by using various multiplexing techniques, and can superimpose and reproduce the superimposed stored data, respectively, thereby providing a very large data storage system. Can be implemented. In this case, multiplexing techniques include angular multiplexing, wavelength multiplexing, and phase code multiplexing.

Generally, the holographic optical information processing system processes digital data in predetermined page units, and the data in such page units is called a datapage. In other words, the holographic optical information processing system processes data in units of data pages.

In one example, the holographic optical information processing system encodes input data in units of data pages and then optically modulates the encoded data pages to convert them into two-dimensional images. In this case, each pixel of the converted data page may correspond to each encoded binary data. Such optical modulation may be performed through a spatial light modulator (SLM).

 An image of the converted data page is projected onto the signal light and is incident to a predetermined position on the optical information storage medium. At the same time, the reference light irradiated from an angle different from the signal light is incident at the predetermined position. At this time, the incident signal light and the reference light interfere with each other in the optical information storage medium, and the image of the data page contained in the signal light is recorded in the optical information storage medium in the form of an interference pattern.

By this process, the image of the data page recorded on the optical information storage medium can be reproduced by irradiating the interference pattern with the reference light. The image of the reproduced data page may be detected through a light receiving array element, for example, a complementary metal-oxide semiconductor (CMOS) or a charge coupled device (CCD). At this time, the detected image of the data page is reproduced as original data through a predetermined signal processing and decoding process.

On the other hand, a separate frame mark is inserted into the data page to easily identify the location of the data area in which the data is stored. These frame marks occupy a part of the data page, such as a border shape around the data area or a part of a corner of the data area.

However, since no information is input to the frame mark for discriminating the data area, it is a meaningless area after the data discrimination is completed. These frame marks occupy very little area on the data page. In fact, there is a problem that the data storage capacity is lost as much as the corresponding area.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and optical information recording is made so that data can be recorded and detected in a frame mark that divides a data area in a data page, thereby increasing the recording and reproduction efficiency relative to the area of the data page. It is an object of the present invention to provide a method, an optical information detecting method and an optical information detecting device.

In order to achieve the above object, the optical information recording method according to the present invention comprises the steps of: encoding the input data in units of pages; by mapping the data of the encoded page unit to a data mark and a frame mark for distinguishing the data region Optically modulating; and loading the modulated data into signal light and storing the modulated data in a storage medium.

Mapping and modulating data to the data area and the frame mark, wherein the frame mark and the outer area except the data area are made of off pixels, and at least one off pixel line is disposed between the frame mark and the data area. You can insert

On the other hand, the optical information detection method according to the present invention comprises the steps of: detecting an image of the data page stored in the optical information storage medium; by analyzing the light intensity distribution of the detected image, detecting the reference pixel at the start of sampling of the data page And detecting data stored in a frame mark and a data area of the data page based on the detected reference pixel.

The detecting of the reference pixel may include calculating light intensity information of each column in the detected data page image and light intensity information of each row; two columns of adjacent neighboring light intensity information of each column. Comparing the calculated light intensity information of each row with the light intensity information of two rows adjacent to each other; and comparing the calculated light intensity information of each row with the maximum light intensity information of the adjacent neighboring columns. Detecting a column having a difference in intensity and a row having the largest difference in light intensity compared to light intensity information of the neighboring rows; and detecting a pixel at a position where the detected column and the row intersect with each other; It may include.

The light intensity information may be a sum of light intensities of pixels belonging to a corresponding column or row.

The reference pixel may be a pixel located in a first column and a first row of the detected image of the optical information.

On the other hand, the optical information detection apparatus according to the present invention includes a light detector for detecting an image of the data page stored in the optical information storage medium; and by analyzing the light intensity distribution of the detected image, by detecting the sampling start position of the data page And an optical information processor for detecting data stored in a frame mark and a data area of the data page.

The optical information processing unit analyzes the light intensity distribution of the detected image to detect a reference pixel at the start of sampling in the frame mark; and the frame mark and the data using the detected reference pixel as a starting position. And a sampling unit for sampling data of the region.

The reference pixel compares the light intensity information of each column of the data page image with the light intensity information of two columns adjacent to each other, and extracts a column having the largest difference between the two adjacent columns and the light intensity, After comparing the light intensity information of each row of the data page image with the light intensity information of two rows adjacent to each other, the column having the largest difference between the two adjacent rows and the light intensity is extracted, and then the extracted column. And pixels positioned at intersections of rows.

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

1 is a simplified diagram showing the configuration of an optical information processing system according to an embodiment of the present invention.

Referring to FIG. 1, an optical information processing system according to an exemplary embodiment of the present invention provides a light source 110 that provides light, and splits the light into a reference beam (R) and a signal beam (S). The optical splitter 120, the first reflection mirror 101 for guiding the reference light R to the optical information storage medium 200, the shutter 130 for controlling the progress of the signal light S, and the signal light S And a second reflecting mirror 102 to guide the spatial light modulator 160.

On the other hand, in the path of the signal light (S) reflected by the optical splitter 120, the data encoding unit 140 for encoding the input data, the mapper 150 for mapping the encoded data in units of pages, and modulates the data page The spatial light modulator 160 is loaded onto the signal light S.

Although not shown, a plurality of optical lenses for reference light processing, that is, a waist configuration lens, a beam expander, and the like are provided on the reference light path, and a plurality of optical lenses for resolving signal light, that is, a reimaging lens, a beam expander, are provided on the signal light path. A field lens or the like may be provided.

The light irradiated from the light source 110 is separated into the reference light R and the signal light S through the light separator 120. In this case, the reference light R is reflected by the first reflection mirror 101 and is incident on the optical information storage medium 200.

Here, an actuator (not shown) may be installed in the first reflection mirror 101. The actuator adjusts the angle of the first reflecting mirror 101 when recording the optical information, and overlaps the optical information by multiplexing the angle of the reference light R crossing the signal light S in the optical information storage medium 200. Make a record.

On the other hand, the signal light (S) is reflected by the second reflecting mirror 102 is incident to the spatial light modulator 160. In this case, the spatial light modulator 160 receives binary data, that is, data page information, in units of encoded pages provided by the data encoding unit 140.

The data page information includes frame mark insertion information. In this case, the frame mark insertion information may include information such as the position of the frame mark to be inserted in the data page imaged in two dimensions.

The mapper 150 maps the data according to the data page information input from the data encoding unit 140 and provides the data to the spatial light modulator 160. In this case, the data page information includes a data area and frame mark insertion information for distinguishing the data area. The frame mark insertion information is also stored in the optical information detecting apparatus 300.

The contents related to the data page into which the frame mark is inserted will be described in detail later with reference to FIG. 3.

In this way, the mapper 150 maps the encoded data into the data area of the data page and the frame mark and provides the encoded data to the spatial light modulator 160.

The spatial light modulator 160 optically modulates the data page information input from the mapper 150 to generate a two-dimensional imaged data page, and loads it on the signal light S incident to the spatial light modulator 160. To enter the optical information storage medium 200.

As such, when the reference light and the signal light are incident on the optical information storage medium 200, the intensity of the interference pattern generated by the interference between the incident reference light R and the signal light S in the optical information storage medium 200. Accordingly, a light induced generation of mobile charge is generated and the interference pattern is recorded. This may be a holographic interference fringe.

In order to reproduce the recorded data, only the reference light R may be irradiated to the optical information storage medium 200. That is, the reference light R passed through the optical separator 120 is incident to the optical information storage medium 200 by the first reflection mirror 101 during reproduction, and the signal light S reflected by the optical separator 120 is reflected. The process is blocked by the shutter 130.

At this time, the reference light R irradiated to the first reflection mirror 101 is diffracted by the interference fringe recorded on the optical information storage medium 200 to reproduce an image of the data page.

Meanwhile, the optical information detecting device 300 detects and restores data from the data area and the frame mark in the image paper of the data page, and the data decoding unit 400 decodes the sampled data. It is provided.

The image of the reproduced data page is detected by the pixel matching (Pixel Matching) by the optical information detecting apparatus 300, and is sampled after a series of processes such as image correction. Subsequently, the sampled data is decoded by the data decoding unit 400 to restore original data.

2 is an exemplary view showing an image of a data page provided by a spatial light modulator according to an embodiment of the present invention.

Referring to FIG. 2, in the data page 10, a data mark 13 and a frame mark 11 for distinguishing the data region 13 are inserted, and the data page 10 is inserted in the data region 13 and the frame mark 11. Input data coded as binary data from the data encoding unit 140 is mapped by the mapper 150.

The frame mark 11 is arranged in the form of a border around the data page 10, and the data regions 13 can be divided into a plurality by connecting the centers of the sides forming the border around the data page 10. .

Here, in the embodiment of the present invention, the plurality of data areas 13 are illustrated and described as being divided into four by the frame marks 11, but the position of the frame marks 11 and the data area 13 The number may vary.

On the other hand, the external area excluding the data area 13 and the frame mark 11 of the data page 10 is composed of off pixels to which data is not mapped. In addition, at least one off pixel line may be inserted between the frame mark 11 and each data region 13. Thus, the frame mark 11 has at least one pixel line positioned between adjacent and adjacent off pixel lines.

 Data coded as binary data from the data encoding unit 140 is divided into on / off pixels and mapped to the frame mark 11 and the data region 13.

3 is a block diagram showing the configuration of an optical information detecting apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the optical information detecting apparatus 300 may include an optical detector 310 for detecting an image of a data page 10 and optical information for detecting data values in a detected image detected by the optical detector 310. The processor 330 is provided.

The light detector 310 detects an image of the data page 10 reproduced from the optical information storage medium 200 by the reference light R. In this case, the light detector 310 may have a 1: 1 pixel matching optical system or a 1: N (N> 1) oversampling optical system. The light detector may be implemented as a light receiving array, for example, a CCD or a CMOS.

On the other hand, the optical information processing unit 330 analyzes the light intensity distribution in the image detected by the light detection unit 310 to detect the sampling start position of the frame mark 11 and the data area 13 to perform sampling.

The optical information processor 330 analyzes the light intensity distribution of the detected image of the data page 10 detected by the optical detector 310 to start sampling of the frame mark 11 and the data region 13. A reference pixel detector 331 for determining the position of the pixel 10a and a sampling unit 333 for sampling using the determined reference pixel 10a position may be provided.

In general, since data sampling is bit tracing from left to right and top to bottom on the detection image of the data page 10, the sampling start position exists at the upper left edge portion of the data page 10 detection image. That is, the pixel may mean the reference pixel 10a.

4 is a flowchart illustrating a method of detecting optical information according to an exemplary embodiment of the present invention, and FIG. 5A is a graph illustrating light intensity difference values of columns of an image of a data page according to an exemplary embodiment of the present invention. 5B is a graph illustrating light intensity difference values of columns of an image of a data page according to an embodiment of the present invention.

5A to 5B, the X axis represents the number of columns (or rows), and the Y axis represents light intensity difference values of the corresponding columns (or rows).

Referring to FIG. 4, in the optical information detecting method according to an exemplary embodiment of the present invention, first, the optical detector 310 of the data page 10 is stored in the optical information storage medium 200 and reproduced by the reference light R. An image is detected (S10).

In this case, the image of the data page 10 detected by the light detector 310 may include a detection image of the data page 10 and an external area. The outer region consists of off pixels because there is no data.

Therefore, in order to extract and sample only the information contained in the detection image of the data page 10 from the image of the data page 10, the sampling start position must be detected.

Accordingly, the reference pixel detector 331 calculates light intensity distribution information of the image of the data page 10 detected by the light detector 310, and is a reference point that is a starting point for sampling data from the detected image of the data page 10. The pixel 10a is detected.

In order to detect the reference pixel 10a, the reference pixel detector 331 may add the sum of the light intensities of each column of the detected datapage 10 image and the sum of the light intensities of each row of the datapage 10 image. To calculate (S20).

Subsequently, the reference pixel detection unit 331 subtracts the sum of the light intensities of each column from the sum of the light intensities of the previous column and the sum of the light intensities of the subsequent columns of the column. Compute the values individually.

In addition, the reference pixel detector 331 subtracts the light intensity difference by subtracting the sum of the light intensities of each row from the sum of the light intensities of the rows before the row. Each value is calculated (S30).

The light intensity difference value may be expressed by Equation 1 below.

Where I _i is the light intensity difference value of the i th column (or row), SUM _i is the light intensity sum value of the pixels of the i th column (or row), and SUM _i-1 is the i-1 th column (or row) The light intensity value of the pixels, SUM _{i + 1,} denotes the light intensity value of the pixels of the I + 1th column (or row).

When the light intensity difference value of each column and the light intensity difference value of each row are calculated, the reference pixel detector 331 extracts each column and row having the largest light intensity difference value. Through this process, the first column and the first row of the data page detection image may be detected (S40).

 Because the data page 10 is composed of a data area 13 having data information, the detection image of the data page 10 has a configuration in which on pixels and off pixels are mixed. Accordingly, columns or rows existing in the detected image of the data page 10 among the images of the data page 10 may have a light intensity sum value of a predetermined level or more on average.

On the other hand, since the pixel lines positioned between the outer region and the frame mark 11 and the data region 13 in the image of the data page 10 are all composed of off pixels, the outer region and the frame mark 11 and data Columns or rows existing in pixel lines located between regions have very weak light intensity values.

Accordingly, the maximum light intensity difference value will be detected by subtracting the light intensity sum of the previous column, which is the outer region, from the light intensity sum of the first column of the data page 10 detection image. Similarly, subtracting the light intensity sum of the previous row, which is the outer region, from the light intensity sum of the first row of the datapage 10 detected image, the largest light intensity difference value will be detected.

Referring to FIG. 6A, it can be seen that the light intensity difference value of the first column where the detection image of the data page 10 starts, that is, the 50th column of the image of the data page 10 is significantly larger than the light intensity difference values of the other columns. have.

6B, it can be seen that the light intensity difference value of the first row where the detection image of the data page 10 starts, that is, the 50th row of the image of the data page, is much larger than the light intensity difference values of the other rows. .

If the first column of the image of the data page 10 and the first row where the detection image of the data page 10 starts are extracted, the reference pixel detector 331 is located at the intersection of the extracted first column and the first row. The pixel to be detected is detected. That is, the reference pixel 10a which is a sampling start position is detected (S50).

When the sampling start position detected in this way, that is, the reference pixel 10a, is used, another frame mark 11 positioned at a distance from a specific column and a row away from the reference pixel 10a on the data page 10 detected image is used. You will find it.

Here, the sampling unit 333 performs sampling over the entire data page using the reference pixel 10a as a reference point. In other words, sampling is performed sequentially from the upper left of the data page 10 to the lower right of the data page 10 to sample the data of the frame mark 11 and the data area 13.

Also, in another embodiment, the sampling unit 333 first samples the data stored in the frame mark 11 from the reference pixel 10a, and the data area 13 from the pixel spaced apart from the reference pixel 10a according to a setting value. The second sampling may be performed on the extended data.

Here, the pixels spaced apart from the reference pixel 10a according to a setting value are compared with two columns adjacent to each other by comparing the light intensity information of each column of the data page 10 image with the light intensity information of the two adjacent columns. The column with the smallest difference in light intensity is extracted, and the light intensity information of each row of the data page 10 image is compared with the light intensity information of two adjacent rows, and the difference between the two adjacent rows and light intensity is compared. Is the smallest row extracted, resulting in the pixel at the point where the extracted column and row intersect.

As described above, the sampling unit 333 sequentially processes data values of pixels that can be sampled in each of the data area 13 and the frame mark 11 after undergoing a series of processes such as image correction. The values are detected (S60).

Subsequently, the sampled data pixel values are decoded by the data decoding unit 400, and the original data is restored.

As described above, the optical information recording method, the optical information detecting method, and the optical information detecting apparatus according to the present invention record and detect the data not only in the data area of the data page but also in the frame mark, thereby recording and reproducing the area of the data page. There is an effect that can increase the efficiency.

Claims (9)

Encoding the input data in units of pages; Optically modulating the encoded page unit data by mapping it to a data area and a frame mark for distinguishing the data area; And And loading the modulated data on the signal light and storing the modulated data in a storage medium. The method of claim 1, wherein mapping and modulating data in the data area and the frame mark comprises: And an external area excluding the frame mark and the data area is formed of off pixels, and at least one off pixel line is inserted between the frame mark and the data area. Detecting an image of a data page stored in the optical information storage medium; Analyzing a light intensity distribution of the detected image to detect a reference pixel at the start of sampling of the data page; and And detecting data stored in a frame mark and a data area of the data page based on the detected reference pixel. The method of claim 3, wherein the detecting of the reference pixel comprises: Calculating light intensity information of each column in the detected data page image and light intensity information of each row; Comparing the calculated light intensity information of each column with the light intensity information of two columns adjacent to each other, and comparing the calculated light intensity information of each row with the light intensity information of two adjacent rows; Detecting a column having the largest light intensity difference compared to the light intensity information of the neighboring columns as a result of the comparison, and a row having the largest light intensity difference compared to the light intensity information of the neighboring rows; And And detecting a pixel at a position where the detected column and the row intersect each other. The method of claim 4, wherein the light intensity information is a sum of light intensities of pixels belonging to a corresponding column or row. The method of claim 4, wherein the reference pixel And a pixel located in a first column and a first row of the detected image of the optical information. An optical detector detecting an image of a data page stored in the optical information storage medium; and And an optical information processor for analyzing a light intensity distribution of the detected image, detecting a sampling start position of the data page, and detecting data stored in a frame mark and a data area of the data page. Information detection device. The optical information processing unit of claim 7, wherein the optical information processing unit A reference pixel detector for analyzing a light intensity distribution of the detected image to detect a reference pixel at the start of sampling in the frame mark; and And a sampling unit for sampling the frame mark and the data of the data area by using the detected reference pixel as a starting position. The method of claim 8, wherein the reference pixel is Comparing the light intensity information of each column of the data page image with the light intensity information of two columns adjacent to each other, and extracting a column having the greatest difference between the two adjacent columns and the light intensity, After comparing the light intensity information of each row of the data page image with the light intensity information of two rows adjacent to each other, the column having the largest difference between the two adjacent rows and the light intensity is extracted, and then the extracted column. And a pixel located at a point where the rows intersect.

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