JP6191669B2 - DATA STORAGE MEDIUM, MANUFACTURING METHOD THEREOF, DATA READING DEVICE, AND DATA READING METHOD - Google Patents

Description

  The present invention relates to a data storage medium, a manufacturing method thereof, a data reading device, and a data reading method.

  Paper as a medium for recording various information has been used for a long time, and even now, a lot of information is recorded on paper. On the other hand, with the development of industry, film (microfilm, etc.) for recording image information such as moving images and still images, and a record board for recording sound information have been used. In recent years, magnetic media have been used as media for recording digital data. Recording media, optical recording media, semiconductor recording media, and the like are used.

  Some of the information recorded on the medium as described above is required to be stored for an extremely long time exceeding 100 years. Each of the above media has a durability that does not hinder use depending on the application. For example, media such as paper, film, and record board are sufficiently durable on a time scale of several years. It can be said that it is a medium having a property. However, on time scales exceeding 100 years, aging degradation cannot be avoided, stored information may be lost, and water or heat may cause damage. For example, if microfilm is made of cellulose acetate as a raw material, it will decompose due to the temperature and humidity of the storage environment, and acetic acid will be generated on the surface, causing a vinegar syndrome that makes it impossible to read data. Is said to be less than 30 years. Although it is said that the lifespan of polyester is about 500 years, it cannot be achieved unless it is stored in an environment defined by standards such as ISO and JIS, and the storage environment is a risk of information loss. It will remain one of the factors.

  In addition, although magnetic recording media, optical recording media, semiconductor recording media, etc. have durability that does not hinder the use of general electronic equipment, they are considered to be durable on a time scale such as several decades. Since it has not been designed, it is not suitable for storing information permanently or semi-permanently. For example, in an EEPROM typified by a flash memory as a semiconductor recording medium, data is recorded and stored by holding charges in the floating gate, but the holding time of the charges in the floating gate depends on the storage environment. In addition, the repeated writing of data may damage the insulating layer and prevent the charge from being retained. A ROM is known as a long-lived semiconductor recording medium. However, it is very expensive to produce a ROM (replica) as a backup from a ROM in which information is recorded and stored.

  Further, the above medium has a problem that it lacks fire resistance and heat resistance. For example, if a fire occurs at the storage location of the above-mentioned medium where information is recorded and stored, the data will be lost due to the heat, so it is practical to store information permanently or semi-permanently on existing media. Is impossible.

  On the other hand, as a method capable of permanently and semipermanently storing information, a method of recording and storing information on a durable medium such as quartz glass has been proposed (see Patent Documents 1 and 2). Specifically, a method of recording data three-dimensionally as a difference in light transmittance in a minute cell in a cylindrical medium, and reading out information using computer tomography technology while rotating the medium (Refer to Patent Document 1), a method of measuring the difference in transmittance by irradiating electromagnetic waves to a cylindrical medium while changing the irradiation angle, and reading out information using a computer tomography technique (Patent Document) 2) has been proposed.

Japanese Patent No. 4991487 Japanese Patent No. 5286246

  As disclosed in the above Patent Documents 1 and 2, if a method of recording and storing information three-dimensionally in a cylindrical quartz glass is used as a medium, information can be stored permanently or semi-permanently. Can be recorded and saved. When reading information recorded and stored in this way, it is necessary to extract information from cells that are three-dimensionally distributed in the medium, so it is necessary to use computer tomography technology to perform Fourier transform processing, etc. There is. However, after a very long time scale of several hundred years, the recorded and stored information cannot be read out unless the same computer tomography technology is used as when recording and storing the information. There is.

  In addition, in order to reduce the risk that information will be lost due to damage to the medium on which the information is recorded / stored, the information is recorded / stored when making a copy as a backup of the medium. It is necessary to prepare a separate quartz glass, and to record and store information newly. For this reason, when there is no original information to be recorded / stored, it is impossible to produce a duplicate, and the work of producing the duplicate is cumbersome and expensive. There is also.

  In view of such problems, the present invention is a data storage medium that is durable against changes in the storage environment, and a data storage medium that can easily produce a replica as a backup of the data storage medium, and An object of the present invention is to provide a manufacturing method, a data reading device, and a data reading method.

  In order to solve the above-described problems, the present invention provides a method for manufacturing a data storage medium in which data is stored, the data comprising quartz having a first surface and a second surface facing the first surface. A pattern data generating step for generating pattern data used when forming a concavo-convex structure on the first surface side of the substrate for storage medium, and the first of the substrate for data storage medium based on the pattern data A concavo-convex structure forming step of forming the concavo-convex structure on a surface, wherein the concavo-convex structure is formed in a data region in a storage region defined on the first surface side of the base material for the data storage medium, A data concavo-convex structure expressing data content of data, and a dummy concavo-convex structure formed in a dummy area other than the data area in the storage area, the pattern data generation step A first step of generating first pattern data corresponding to the data concavo-convex structure, and a second step of generating the pattern data by adding second pattern data corresponding to the dummy concavo-convex structure to the first pattern data. And in the second step, based on the first pattern data, the second pattern data is converted to the first pattern so that the area density of the concavo-convex structure in the storage region is substantially uniform. Provided is a method for manufacturing a data storage medium characterized by adding to data (Invention 1).

  When forming a concavo-convex structure in which data to be stored is converted into a physical structure on a data storage medium, a concavo-convex structure is formed in a part of the storage area depending on the amount of data (number of bits in the data bit string). It may not be done. In addition, when storing multiple pieces of data with different data contents in one data storage medium, the concave / convex structure corresponding to each data is Regions where no structure is formed may be provided. When a replica of such a data storage medium is manufactured using an imprint technique, the data storage medium may have a region having no uneven structure, which may cause a defect in the transfer pattern. When a defect occurs in the transfer pattern, the data content of the data expressed by the uneven structure formed on the replica of the data storage medium (data restored from the uneven structure of the replica) is stored in the data storage medium. The data content of the stored data may be different. However, according to the above invention (Invention 1), even if there is a region without a concavo-convex structure, a dummy concavo-convex structure is formed in the region, so that a replica can be produced with high accuracy using imprint technology. Can be produced.

  In the said invention (invention 1), in the said pattern data generation process, the pattern data generation area | region equivalent to the said preservation | save area | region is set, and the said 1st figure cell corresponding to the said data uneven structure is said pattern in the said 1st process. The first pattern data is generated by arranging in a data generation area, and the second step is based on the first pattern data and sets an area in which the first graphic cell is arranged in the pattern data generation area. Extracting as one pattern data generation region, extracting a region other than the first pattern data generation region as a second pattern data generation region corresponding to the dummy region, and dummy irregularities in the second pattern data generation region Preferably, the method includes a step of arranging the second graphic cell corresponding to the structure to generate the second pattern data. There (invention 2).

  In the above invention (Invention 1), the storage area includes a plurality of unit storage areas arranged in a matrix, and the data uneven structure includes a plurality of unit data obtained by dividing the data. A plurality of unit data concavo-convex structures expressing the data content of the plurality of unit pattern data generation regions corresponding to each of the plurality of unit storage regions in the pattern data generation step, in the first step, A first graphic cell corresponding to each unit data concavo-convex structure is arranged in each unit pattern data generation area in the matrix arrangement order of the plurality of unit pattern data generation areas to generate the first pattern data, and the second In the process, the first graphic cell is arranged in each of the plurality of unit pattern data generation areas based on the first pattern data. Extracting a region obtained as a first pattern data generation region, extracting a region other than the first pattern data generation region as a second pattern data generation region corresponding to the dummy region, and generating the second pattern data It is preferable to include a step of generating the second pattern data by arranging a second graphic cell corresponding to the dummy concavo-convex structure in the region (Invention 3).

  In the above invention (Invention 3), in the step of generating the second pattern data, the first pattern data generation area with respect to a total area of the first pattern data generation region in which the first graphic cells are arranged is based on the first pattern data. A ratio of the total area of one graphic cell is calculated, and the second graphic cell is arranged in the second pattern data generation region at an area ratio substantially the same as the ratio of the total area of the first graphic cell. Two pattern data may be generated (invention 4), and the unit pattern data generation region located around the second pattern data generation region is extracted based on the first pattern data, and the extracted unit pattern The ratio of the total area of the first graphic cell to the total area of the data generation area is calculated, and the second pattern is substantially the same as the ratio of the total area of the first graphic cell. It may generate the second pattern data by arranging the second graphic cell over data generation region (invention 5).

  In the above invention (Invention 5), in the step of generating the second pattern data, from the ratio of the total area of the first graphic cells in the unit pattern data generation region located around the second pattern data generation region The gradient of the ratio of the total area of the first graphic cells in the unit pattern data generation area is calculated, and the second pattern data generation area is calculated based on the gradient of the ratio of the total area of the first graphic cells. It is preferable that the second pattern data is generated by arranging two graphic cells (invention 6).

  In the above inventions (Inventions 1 to 6), the concavo-convex structure further includes a determination concavo-convex structure for determining a boundary between the data concavo-convex structure and the dummy concavo-convex structure, and the pattern data generation step includes the first step. The method further includes a step of adding third pattern data corresponding to the determination uneven structure to the first pattern data generated in the step, and the first pattern data is added to the first pattern data in the second step. It is preferable to add the second pattern data to the pattern data (Invention 7).

  In the above inventions (Inventions 1 to 7), the data uneven structure and the dummy uneven structure may have substantially the same dimensions as each other (Invention 8).

Further, the present invention is a data storage medium in which data is stored, and is set on a base material made of quartz having a first surface and a second surface opposite to the first surface, and the first surface of the base material. A data non-storage area located between a plurality of unit storage areas arranged in parallel in at least one direction and the adjacent unit storage areas. The concavo-convex structure is formed in a data area in the unit storage area, and is a dummy that is an area other than the data area in the unit storage area. A dummy pattern formed in a region, and a determination pattern formed in the unit storage region for determining a boundary between the data pattern and the dummy pattern, Each data pattern and the dummy pattern, data, wherein the areal density of the uneven structure in the storage area is formed on each of the data area and the dummy area so as to be substantially uniform A storage medium is provided (Invention 9). In the above invention (Invention 9), the data pattern and the dummy pattern have substantially the same shape and size, and the discrimination pattern has a shape and size different from the data pattern and the dummy pattern. Is preferred (Invention 10).

Furthermore, the present invention is an apparatus for reading data stored in a data storage medium according to the above inventions (Inventions 9 and 10), an image data acquisition unit for acquiring image data including the storage area, and the image A data reading unit comprising: a data reading unit that extracts the data pattern of the concavo-convex structure formed in the storage area from data and reads the data based on the extracted data pattern An apparatus is provided (Invention 11).

In the above invention (invention 11), the pre-Symbol data reading unit, as an index the Determination pattern, from the image data, it is preferable to extract the data pattern of said convex-concave structure (invention 12).

Furthermore, the present invention is a method of reading data stored in a data storage medium according to the above inventions (Inventions 9 and 10), an image data acquisition step of acquiring image data including the storage area, A data reading step of extracting the data pattern of the concavo-convex structure formed in the storage area from image data, and reading the data based on the extracted data pattern. A reading method is provided (Invention 13).

In the above invention (invention 13), before Symbol data reading process, as an index the Determination pattern, from the image data, it is preferable to extract the data pattern of said convex-concave structure (invention 14).

  ADVANTAGE OF THE INVENTION According to this invention, it is a data storage medium which is durable with respect to the change of a storage environment, Comprising: The data storage medium which can produce easily the replica as a backup of the said data storage medium, its manufacturing method, Data reading An apparatus and a data reading method can be provided.

FIG. 1 is a plan view showing a schematic configuration of a data storage medium according to an embodiment of the present invention. FIG. 2 is a plan view showing a schematic configuration of the unit storage area according to the embodiment of the present invention. FIG. 3 is a plan view showing a storage area in one embodiment of the present invention. 4 is a partially enlarged cut end view of the data storage medium according to the embodiment of the present invention, which is a cut end view taken along the line II in FIG. FIG. 5 is a plan view showing a pattern representing numbers of row numbers and column numbers of an address pattern in one embodiment of the present invention. FIG. 6 is a plan view showing the configuration of the boundary pattern in one embodiment of the present invention. FIG. 7 is a plan view showing an example of the arrangement of boundary patterns in one embodiment of the present invention. FIG. 8 is a partial plan view showing an arrangement example of the unit data pattern, dummy pattern, boundary pattern, address pattern, and boundary pattern in one embodiment of the present invention. FIG. 9 is a schematic diagram illustrating a process of generating drawing data according to an embodiment of the present invention. FIG. 10 is a perspective view showing steps of a method for manufacturing a data storage medium according to an embodiment of the present invention. FIG. 11 is a process flow diagram illustrating a process of manufacturing a replica of a data storage medium according to an embodiment of the present invention. FIG. 12 is a block diagram schematically showing the configuration of the data reading device in one embodiment of the present invention. FIG. 13 is a partially enlarged perspective view schematically showing the configuration of the data storage medium in one embodiment of the present invention.

Embodiments of the present invention will be described with reference to the drawings.
[Data storage medium]
FIG. 1 is a plan view illustrating a schematic configuration of a data storage medium according to the present embodiment, FIG. 2 is a plan view illustrating a schematic configuration of a unit storage area according to the present embodiment, and FIG. 3 illustrates the present embodiment. FIG. 4 is a partially enlarged cut end view of the data storage medium according to the present embodiment, which is a cut end view taken along the line II in FIG.

  The data storage medium 1 according to the present embodiment has a first surface 21 and a second surface 22 opposite to the first surface 21, and a base material 2 made of substantially rectangular quartz glass, and a second surface of the base material 2. And a concavo-convex structure formed in the storage area SA set on the first surface 21.

  In the storage area SA, a plurality of unit storage areas UA are arranged in parallel in a matrix arrangement of M rows × N columns (one of M and N is an integer of 2 or more and the other is an integer of 1 or more). Has been. As shown in FIG. 3, in the present embodiment, 48 unit storage areas UA (UA1 to UA48) are arranged in parallel in a matrix arrangement of 8 rows (M = 8) × 6 columns (N = 6). However, the present invention is not limited to this embodiment.

  The storage area SA includes a plurality of unit storage areas UA and a saddle-shaped data non-storage area NA located between adjacent unit storage areas UA. In the present embodiment, each unit storage area UA is an area where unit data patterns 31, dummy patterns 32, and discrimination patterns 33 as concavo-convex structures are formed, and the data non-storage area NA includes address patterns 4 and boundary patterns. This is a region where 5 is formed.

  The size of the unit storage area UA can be set as appropriate according to the size of the shootable area in the imaging unit 111 described later. Further, the size of the data non-storage area NA is not particularly limited as long as it is at least the size capable of forming the address pattern 4, but by reducing the size of the data non-storage area NA as much as possible, the storage area SA The proportion of the unit storage area UA can be increased, and the data recording capacity can be increased.

  The unit data pattern 31 formed in each unit storage area UA is a recess (hole) representing the data content (unit bit string) of the unit data obtained by dividing the data recorded and stored in the data storage medium 1 into a plurality of units. 311 and convex portions (portions where no holes exist) 312. In the present embodiment, “1” in the unit bit string of the unit data is defined as the concave portion 311, and “0” is defined as the convex portion 312. For example, in FIG. 2, unit data represented by a unit bit string (unit bit matrix) “1010011101...” From the upper left is recorded and stored in the unit storage area UA of the data storage medium 1. In the unit bit string, “1” may be defined as the convex portion 312 and “0” may be defined as the concave portion 311.

  The type of data recorded / stored in the data storage medium 1 is not particularly limited, and examples thereof include text data, image data such as moving images and still images, audio data, and the like.

  In each unit storage area UA, an area where the unit data pattern 31 is formed is a data area DTA, and an area other than the data area DTA in the unit storage area UA is a dummy area DMA. A dummy pattern 32 is formed in the dummy area DMA.

  The ratio of the total area of the dummy pattern 32 (recess 321) to the total area of the dummy area DMA (hereinafter referred to as “area density of the dummy pattern 32”) is the unit data pattern 31 (recess 311) relative to the total area of the data area DTA. Of the total area (hereinafter referred to as “area density of the unit data pattern 31”). Specifically, the area density of the dummy pattern 32 is about 90 to 110%, preferably about 95 to 105% of the area density of the unit data pattern 31. Since the area density of the dummy pattern 32 is substantially the same as the area density of the unit data pattern 31, a copy of the data storage medium 1 is produced by imprint processing using the data storage medium 1 as described later. In doing so, it is possible to prevent the occurrence of pattern defects in the transfer pattern.

  The unit data pattern 31 and the dummy pattern 32 preferably have substantially the same shape (plan view shape). As shown in FIG. 2, the concave portions 311 and 321 constituting the unit data pattern 31 and the dummy pattern 32 in the present embodiment have a substantially square hole shape in plan view. The dimension of the concave portion 311 of the unit data pattern 31 may be a dimension that allows the concave portion 311 to be optically recognized by a general image sensor, but in order to increase the data capacity that can be recorded and stored in the data storage medium 1. The dimension of the recess 311 of the unit data pattern 31 can be set to, for example, 400 μm or less, preferably about 100 to 250 μm. The dimension of the concave portion 321 of the dummy pattern 32 is not particularly limited, but is preferably substantially the same as the dimension of the concave portion 311 of the unit data pattern 31. Since the shape and dimensions of the concave portion 311 of the unit data pattern 31 and the concave portion 321 of the dummy pattern 32 are substantially the same, a duplicate of the data storage medium 1 is produced by imprint processing using the data storage medium 1. In doing so, it is possible to prevent the occurrence of pattern defects in the transfer pattern.

  In the present embodiment, the unit data pattern 31 and the dummy pattern 32 can be formed in one unit storage area UA. When the unit data pattern 31 (recess 311) and the dummy pattern 32 (321) have substantially the same shape and dimensions, the unit data pattern 31 (data area DTA) and the dummy pattern 32 (dummy area DMA). It becomes difficult to discriminate the boundary. Therefore, in the present embodiment, among the plurality of unit data patterns 31 corresponding to each bit of the data bit string, the unit data pattern 31 (concave part 311 or convex part 312) corresponding to the last bit of the data bit string, A discrimination pattern 33 that serves to clearly discriminate the boundary between the unit data pattern 31 (data area DTA) and the dummy pattern 32 (dummy area DMA) is formed between the dummy pattern 32 and the dummy pattern 32.

  The discrimination pattern 33 can be configured as a recess 331 having a shape and a size different from those of the unit data pattern 31 (recess 311) and the dummy pattern 32 (recess 321) in order to reliably perform the role. In the present embodiment, the shape of the discrimination pattern 33 (planar shape) is a substantially rectangular shape whose longitudinal direction is along the row direction. Accordingly, when data is read from the data storage medium 1 in the data reading device 100 described later, only the unit data pattern 31 can be selectively extracted, and the data stored in the data storage medium 1 is read accurately. be able to.

  Since most of the data stored in the data storage medium 1 includes a control symbol (EOF) indicating the end of the data file in the data content, the control indicating the end of the data file is not provided with a separate discrimination pattern 33. A pattern corresponding to a symbol may be used as the discrimination pattern 33. Further, a pattern corresponding to a bit string obtained by binarizing the same symbol as the control symbol may be used as the discrimination pattern 33, or a binarized bit string representing the end of the data file is separately defined and corresponding to the bit string. A pattern to be used may be used as the discrimination pattern 33. In the present embodiment, at least one type of discrimination pattern 33 may be formed, but a plurality of types of patterns (for example, unit data pattern 31 (concave portion 311) and dummy pattern 32 (concave portion 321) are different in shape and Patterns having different dimensions (recesses 331) and two types of patterns corresponding to control symbols representing the end of the data file) may be formed as the discrimination pattern 33.

  In the present embodiment, the address pattern 4 formed in the data non-storage area NA is constituted by a concave portion 41 and a convex portion 42 that represent position information of each unit storage area UA in the storage area SA. In the present embodiment, the address pattern 4 representing the position information of each unit storage area UA in the storage area SA is the p-th line (p is an integer from 1 to M) representing the parallel position of each unit storage area UA. ) And q-th column (q is an integer of 1 or more and N or less), and a pattern (see FIG. 5) simulating braille representing numbers of row numbers and column numbers (p, q) is formed in the concave portion 41 and the convex portion 42. It is expressed by. In FIG. 2, the address pattern 4 indicates that the unit storage area UA is an area located at the 04th row and the 02th column.

  Note that the address pattern 4 in the present embodiment may be configured by the concavo-convex structure 4 (concave portion 41 and convex portion 42) representing a bit string obtained by binarizing the numbers of the row number and the column number, like the unit data pattern UP. Good.

  The boundary pattern 5 is a pattern that indicates a boundary between one unit storage area UA and another unit storage area UA that is adjacent in the row direction and the column direction via the data non-storage area NA. Each unit storage area UA is formed so as to be located outside the four corners. Since the boundary pattern 5 is formed, each unit storage area UA can be easily recognized by the imaging unit 111 and is recorded and stored as a plurality of unit data patterns 31 as described later. Data can be read accurately.

  In this embodiment, the boundary pattern 5 is substantially cross-shaped, and is the length of one pattern 51 of the four patterns 51 to 54 extending outward from the intersection L (the extension of the pattern from the intersection). The length in the direction) is shorter than the lengths of the other three patterns 52 to 54 (see FIG. 6A). The boundary pattern 5 having such a shape is formed so as to be rotated by 90 ° in the parallel order of the plurality of unit storage areas UA in the storage area SA (order from the upper left to the horizontal direction in FIG. 3). (See FIG. 7). As will be described later, when data recorded / saved in the data storage medium 1 according to the present embodiment is read, the image data of each unit storage area UA is compared with the data storage medium 1 relative to the imaging unit 111. Get while moving to. Therefore, each time the image capturing unit 111 moves, the image capturing unit 111 is aligned and image data is acquired. However, the boundary pattern 5 is rotated by 90 ° in order of the unit storage areas UA in parallel. Image data can be acquired in the parallel order of the unit storage areas UA while scanning the imaging unit 111.

  In addition, the boundary pattern 5 may be substantially L-shaped (having two patterns orthogonal to each other extending in two directions from the reference point Cp) as another aspect (plan view shape) (see FIG. 6 (b)), which is substantially cross-shaped, and the length of the four patterns extending outward from the reference point Cp (the length in the extending direction of the pattern from the intersection) is substantially the same. It is also possible (see FIG. 6C).

  As shown in FIG. 8, the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, and the address pattern 4 are all formed so as to overlap the intersection PI of the virtual grid Gr set in the storage area SA. The boundary pattern 5 is formed so as to overlap the grid lines of the virtual grid Gr. More specifically, each reference point Cp of the unit data pattern 31 (recess 311), dummy pattern 32 (recess 321), discrimination pattern 33 (recess 331), and address pattern 4 (recess 41) is an intersection of the virtual grid Gr. The reference point Cp of the boundary pattern 5 overlaps the grid line of the virtual grid Gr so as to overlap with PI, and is positioned approximately in the middle of the adjacent intersection PI (intersection PI adjacent in the vertical direction in FIG. 8). A unit data pattern 31, a dummy pattern 32, a discrimination pattern 33, an address pattern 4 and a boundary pattern 5 are formed. Here, the reference point Cp of the unit data pattern 31, the dummy pattern 32, and the address pattern 4 is a center point in the plan view of the concave portions 311, 321, and 41 constituting the unit data pattern 31, the dummy pattern 32, and the address pattern 4. The reference point Cp of the discrimination pattern 33 is a point eccentric to the left in the row direction in plan view, and the reference point Cp of the boundary pattern 5 is a substantially cross-shaped intersection L. It is sufficient that at least the reference point Cp of the unit data pattern 31, the dummy pattern 32, and the discrimination pattern 33 is formed so as to overlap the intersection point PI of the virtual grid Gr, and the reference point Cp of the address pattern 4 and the boundary pattern 5 is It may overlap with the intersection point PI of the virtual grid Gr, may overlap with the grid line of the virtual grid Gr but may not overlap with the intersection point PI, and may be overlapped with either the intersection point PI or the grid line of the virtual grid Gr. It does not have to overlap.

  In the data storage medium 1 according to the present embodiment having the above-described configuration, the data content of the recorded / stored data is an uneven structure (unit data pattern 31) formed in each unit storage area UA of the storage area SA. ). The data storage medium 1 can be manufactured by processing a base material made of quartz and has extremely excellent heat resistance and water resistance. Therefore, even if the storage environment changes, the recorded / stored data is not lost, and the data can be stored for a very long time (in units of several hundred years or more).

  In the data storage medium 1 according to the present embodiment, data is recorded and stored by the concavo-convex structure (unit data pattern 31) formed on the first surface 21 of the substrate 2. Therefore, as will be described later, by performing imprint lithography using the data storage medium 1, a copy (backup) of the data storage medium 1 on which the data is recorded / stored is transferred to the data (digital data). Even if it does not exist, it can be easily produced. The dummy pattern 32 is formed in an area where the unit data pattern 31 is not formed (dummy area DMA) in the data storage medium 1, thereby preventing transfer failure due to imprint processing using the data storage medium 1. And a replica (backup) can be produced with high accuracy.

  Furthermore, since the data recorded / stored in the data storage medium 1 according to the present embodiment is expressed by a concavo-convex structure that can be optically recognized using a general imaging device, in the very long-term future However, the data can be easily restored simply by imaging the concavo-convex structure (the concave portion 311 and the convex portion 312 of the unit data pattern 31) using the imaging element existing at that time and converting it into a bit string.

  Furthermore, in the data storage medium 1 according to the present embodiment, the address pattern 4 indicating the position in the storage area SA of each unit storage area UA in which data is recorded and stored as an uneven structure is formed. Even when a part of data recorded / stored in the storage medium 1 (unit data patterns 31 formed in some unit storage areas UA among the plurality of unit storage areas UA) is read out, Based on the address pattern 4, the target data (part of the data) can be easily read. Further, even when a part of the concavo-convex structure (the concave part 311 of the unit data pattern 31) formed in the unit storage area UA is damaged, the unit storage in which a part of the concavo-convex structure is damaged. Since the area UA can be specified by the address pattern 4, if a copy (backup) of the data storage medium 1 is prepared in advance, the data recorded and stored in the unit storage area UA from the copy is stored. Data that can be easily read and combined with data read from the other unit storage area UA of the data storage medium 1 can be restored.

[Method of manufacturing data storage medium]
The data storage medium 1 having the above-described configuration can be manufactured as follows. FIG. 9 is a flowchart schematically showing a process of generating drawing data as a pre-stage for producing the data storage medium 1 according to this embodiment, and FIG. 10 shows the production of the data storage medium 1 according to this embodiment. It is a flowchart which shows the process to do with a cut end view.

[Drawing data generation process]
Based on the data D recorded and stored in the data storage medium 1, first drawing data for forming the unit data pattern 31 in the plurality of unit storage areas UA in the storage area SA of the data storage medium 1 is generated.

Specifically, first, all the bit strings of the data D are divided into X unit bit strings (X is an integer of 2 or more) from the head in a predetermined bit length unit, and unit data including the unit bit string is included. UD _{1 to} UD _X are generated. The bit length of the unit bit string of each unit data UD can be set to be the same as the bit length that can be recorded and stored in the unit storage area UA. When data can be stored in a bit matrix of 8 rows × 16 columns in each unit storage area UA in this embodiment, all the bit strings of data D to be recorded / stored are unit data of unit bit strings of 128 bits from the beginning. Divide into UD.

Next, the unit bit string of each unit data UD is converted into a unit bit matrix UM of 8 rows × 16 columns, and unit pattern data D ₃₁ is generated based on the unit bit matrix UM. In this embodiment, at this time, the virtual grid Gr is defined in the unit pattern data generation area corresponding to the unit storage area UA, and the bits of the unit bit matrix UM are overlapped with the intersection PI of the virtual grid Gr. A graphic cell (square graphic cell) corresponding to the recess 311 is arranged only at a position corresponding to “1”, and no graphic cell is arranged at a position corresponding to bit “0” (see FIG. 8). The unit pattern data D ₃₁ represents 128-bit information constituting the unit bit matrix UM depending on the presence or absence of a graphic cell at each position constituting the 8-row × 16-column matrix. The unit pattern data D ₃₁ is used as drawing data when the unit data pattern 31 is formed in the unit storage area UA.

Then, out of the unit pattern data D _31, the unit pattern data D ₃₁ of the unit bit string UD _X including the end of the bit string of the data D, and adds the determined pattern data D _33. Specifically, if the end of the bit string of the data D is bit “1”, the figure cell (rectangular figure) corresponding to the discrimination pattern 33 is placed after the figure cell arranged at the end in the unit pattern data D ₃₁ . Cell). On the other hand, if the end of the bit string of the data D is bit “0”, the graphic corresponding to the discrimination pattern 33 follows the intersection PI of the virtual grid Gr in which no graphic cell is arranged at the end in the unit pattern data D ₃₁ . Cells (rectangular graphic cells) are arranged (see FIG. 9).

The unit pattern data D ₃₁ to which the discrimination pattern data D ₃₃ is added in this way is arranged in a matrix so as to provide a saddle-like data non-storage area NA, and each unit pattern data D arranged in a matrix is provided. Address pattern data D ₄ and boundary pattern data D ₅ corresponding to ₃₁ are added.

The address pattern data D ₄ is added along the arrangement order of the unit data UD in the data D recorded and stored in the data storage medium 1. The address pattern data D ₄ is used in the data non-conserved regions NA as the drawing data for forming the address pattern 4.

An area (dummy pattern) corresponding to the dummy area DMA is generated from the first drawing data including the unit pattern data D ₃₁ , the discrimination pattern data D ₃₃ , the address pattern data D ₄ , and the boundary pattern data D ₅ thus generated. Data generation area) is extracted. The dummy pattern data area, based on the discrimination pattern data D _33, the intersection graphic cell corresponding to the determination pattern 33 according to a matrix arrangement order after the intersection PI disposed PI (the intersection PI of graphic cells are not disposed) Extracted as a region to include.

In this way, the dummy pattern data generation area is extracted, and the area density AD _UP (% of the unit data pattern 31 in the other area (the area to which the unit pattern data D ₃₁ is added in all the unit pattern data generation areas). ) Is calculated. The area density AD _UP is an area in which graphic cells corresponding to the unit pattern data 31 are arranged in all the unit storage areas UA (refer to FIG. 3, a part of the unit storage areas UA1 to UA13 and UA14, UA17 to UA28, UA30 to UA38, a part of UA39, and a unit pattern data generation area corresponding to UA42 to UA48) to the total area of all graphic cells arranged in the area The In the present embodiment, the virtual grid Gr is defined so that the pitch of adjacent graphic cells is twice the size of the graphic cell corresponding to the unit data pattern 31 (the length of one side). If the graphic cell is arranged at the intersection point PI in all the unit pattern data generation regions, the area density is 25%. Therefore, the area density AD _UP (%) of the unit data pattern 31 is calculated by the following formula.

AD _UP = N _b1 / N _ab × 25
In the above formula, N _b1 represents “total number of bits“ 1 ”in all bit strings of data D”, and N _ab represents “total number of bits of data D”.

Using the calculated area density AD _UP (%) as an index, dummy pattern data D ₃₂ is added to the extracted dummy pattern data generation region. Since the area density AD _UP (%) calculated as described above represents the area density of the unit data pattern 31 in the storage area SA, the area density of the dummy pattern 32 in the dummy pattern data generation area is the area density AD. _The graphic cells corresponding to the dummy pattern 32 are arranged in the dummy pattern data generation region so that the area density is substantially the same as _UP (about 90 to 110%, preferably about 95 to 105% of the area density AD _UP ). To do. When a graphic cell corresponding to the dummy pattern 32 is arranged, for example, an intersection point PI in which a graphic cell corresponding to the dummy pattern 32 is arranged among the intersection points PI in the dummy pattern data generation area is determined using a random number table or the like. can do. In this way, drawing data can be generated by generating dummy pattern data D ₃₂ (second drawing data) and adding it to the first drawing data.

[Data storage medium production process]
Subsequently, a data storage medium substrate 10 made of quartz having a first surface 11 and a second surface 12 opposite to the first surface 11 is prepared, and unit data is provided on the first surface 11 of the substrate 10. Resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ and R ₅ corresponding to the pattern 31, dummy pattern 32, discrimination pattern 33, address pattern 4 and boundary pattern ₅ are formed (see FIG. 10A). .

Such resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ , and R ₅ are formed using a conventionally known exposure apparatus (electron beam drawing apparatus, laser drawing apparatus, etc.) used in a semiconductor manufacturing process or the like. obtain. Using this exposure apparatus, based on the drawing data generated as described above, a pattern latent image is formed on the resist layer formed on the first surface 11 side of the substrate 10 for data storage medium, and developed. By performing the processing, resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ , R ₅ can be formed.

The material constituting the resist layer is not particularly limited, and a conventionally known energy beam sensitive resist material (for example, electron beam sensitive resist material) can be used. In the example shown in FIG. 10 (a), since a positive energy ray sensitive resist material is used, the resist layer R on which the pattern latent image is formed is subjected to a development process, thereby forming a concave resist pattern R. ₃₁ , R ₃₂ , R ₃₃ , R ₄ and R ₅ are formed.

After forming a resist pattern _{R 31, R 32, R 33} , R 4, R 5 In this way, using the resist pattern _{R 31, R 32, R 33} , R 4, R 5 as a mask, wet etching Alternatively, the first surface 11 of the data storage medium substrate 10 is etched by a dry etching method (see FIG. 10B), and the remaining resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ , and R ₅ are removed. . Thereby, the data storage medium 1 according to the present embodiment, in which the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, the address pattern 4 and the boundary pattern 5 are formed on the first surface 21 of the base material 2, is manufactured. can do. In addition, you may use what the hard mask layer which consists of chromium oxide etc. is formed in the 1st surface 11 side surface of the base material 10 for data storage media. In this case, a hard mask pattern is formed by etching using the resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ , and R ₅ as a mask, and the first data storage medium substrate 10 is formed using the hard mask pattern as a mask. The data storage medium 1 can be manufactured by etching the surface 11 and removing the hard mask pattern.

  A method for producing a copy of the data storage medium 1 thus produced will be described. FIG. 11 is a process flow diagram showing a process of producing a replica of the data storage medium 1 according to the present embodiment at a cut end face.

  First, the data storage medium 1 in which the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, the address pattern 4 and the boundary pattern 5 are formed on the first surface 21 of the substrate 2, the first surface 51, and the opposite side. A substrate 50 having a second surface 52 and having a resin layer 60 provided on the first surface 51 is prepared (see FIG. 11A).

  The material constituting the substrate 50 is not particularly limited, and examples thereof include a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an acrylic glass substrate, and a borosilicate glass substrate. A glass substrate; a single-layer substrate composed of a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, other resin substrates such as a polyolefin substrate, or a laminated substrate obtained by laminating two or more arbitrarily selected from the above substrates. It is done.

  In the resin layer 60, the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, the address pattern 4 and the boundary pattern 5 of the data storage medium 1 are formed in a later-described process (see FIG. 11B). Layer. As the resin material constituting the resin layer 60, a resin material such as a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin can be used, and more specifically, an acrylic resin, a styrene resin, an olefin resin, or the like. Resins, polycarbonate resins, polyester resins, epoxy resins, silicone resins, and the like can be used.

  Next, the first surface 21 of the data storage medium 1 is pressed against the resin layer 60 on the substrate 50, and the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, and the address of the data storage medium 1 are applied to the resin layer 60. The pattern 4 and the boundary pattern 5 are transferred to form a reverse pattern thereof (see FIG. 11B). After the resin layer 60 is cured, the data storage medium 1 and the substrate 50 are peeled from the resin layer 60, whereby the resin mold 70 is manufactured (see FIG. 11C). At this time, since the dummy pattern 32 is formed in the area where the unit data pattern 31 is not formed (dummy area DMA) in the data storage medium 1 according to the present embodiment, the first surface of the data storage medium 1 is formed. On the entire surface of 21, the stress applied at the time of peeling becomes substantially uniform. Therefore, the resin mold 70 having a highly accurate reversal pattern can be produced without causing defective transfer.

  Subsequently, a replica base material 10 ′ made of quartz having a first surface 11 ′ and a second surface 12 ′ opposite to the first surface 11 ′ is prepared. On the first surface 11 ′ of the replica base material 10 ′. A resist layer 80 is formed, the surface of the resin mold 70 on which the reverse pattern is formed is pressed against the resist layer 80, and the resist layer 80 is cured in this state (see FIG. 11D).

  After the resist layer 80 is cured, the resin mold 70 is peeled from the resist layer 80 to form a resist pattern 90 to which the reverse pattern of the resin mold 70 is transferred (see FIG. 11E). Similarly, at this time, the resin mold 70 has a reversal pattern in which the dummy pattern 32 of the data storage medium 1 according to the present embodiment is transferred with high accuracy, so that the entire surface of the resin mold 70 is peeled off. The stress becomes substantially uniform.

  Then, the first surface 11 ′ of the duplicate substrate 10 ′ is etched using the resist pattern 90 as a mask. Thereby, a replica 1 'of the data storage medium 1 can be produced (see FIG. 11 (f)). As long as the curing of the resist layer 80 is not affected, a material in which a hard mask layer made of chromium oxide or the like is formed on the first surface 11 ′ side surface of the replica base material 10 ′ as necessary is used. May be. In this case, a resist pattern 90 is formed on the hard mask layer, a hard mask pattern is formed by etching using the resist pattern 90 as a mask, and the first surface 11 of the replica substrate 10 ′ is formed using the hard mask pattern as a mask. After 'is etched, the hard mask pattern is removed, whereby a replica 1' of the data storage medium 1 can be produced.

  As described above, according to the present embodiment, the data storage medium 1 can be easily and accurately manufactured by using a conventionally known lithography technique used in a semiconductor manufacturing process or the like. In addition, a copy as a backup of data recorded / stored in the case where the data storage medium 1 is damaged can be easily made by using a conventionally known imprint technique.

[Data reading device / data reading method]
A data reading apparatus for reading data recorded and stored in the data storage medium 1 having the above-described configuration and a data reading method using the data reading apparatus will be described. FIG. 12 is a block diagram showing a schematic configuration of the data reading device in the present embodiment.

  The data reading device 100 according to the present embodiment includes an image data acquisition unit 110 that acquires image data in the storage area SA of the data storage medium 1, a control unit 121 that performs data processing based on the image data, and the image data acquisition unit. And a control device 120 having a storage unit 122 that stores the image data acquired by 110, various data generated by the control unit 121, various programs, and the like.

  The image data acquisition unit 110 captures an image in a predetermined shooting target area such as a CCD camera as image data, and the unit storage area UA in which the shooting target area is the storage area SA of the data storage medium 1. And a scanning unit 112 that performs a scanning process so as to sequentially move relative to the unit 111. A general-purpose optical microscope or the like can be used as the image data acquisition unit 110.

  The control unit 121 performs arithmetic processing according to instructions of various programs. Specifically, the control unit 121 reads unit data (unit bit string) based on the image data of the unit data pattern 31 formed in each unit storage area UA, or based on the image data of the determination pattern 33. The end of the unit data (unit bit string) is determined, the position information of the unit storage area UA is read based on the image data of the address pattern 4 formed in the data non-storage area NA, or the image data acquisition unit 110 Data recorded or stored in the data storage medium 1 by storing the acquired image data, various generated data, or the like in the storage unit 122 or combining the read unit data (unit bit string). Or restore.

  The storage unit 122 stores the image data of the storage area SA (unit storage area UA) acquired by the image data acquisition unit 110, and based on the image data of the unit data pattern 31 formed in the unit storage area UA. The read unit data (unit bit string) and the position information of the unit storage area UA read based on the image data of the address pattern 4 are stored in association with each other. A general-purpose computer or the like can be used as the control device 120 having the control unit 121 and the storage unit 122.

  A method of reading data recorded / stored in the data storage medium 1 using the data reading device 100 having such a configuration will be described.

  First, when the data storage medium 1 is set in the image data acquisition unit 110, the image data acquisition unit 110 causes the scanning unit 112 to move the data storage medium 1 relative to the imaging unit 111, and the imaging unit 111. Thus, each unit storage area UA of the storage area SA of the data storage medium 1 is picked up in order, and image data including each unit storage area UA and the image of the address pattern 4 corresponding thereto is acquired.

  The scanning unit 112 of the image data acquisition unit 110 recognizes the boundary pattern 5 of the data storage medium 1 so that the unit storage area UA and the corresponding address pattern 4 are included in the imaging target area. 1 is moved relative to the imaging unit 111. As a result, the image captured by the imaging unit 111 includes at least one unit storage area UA and the corresponding address pattern 4.

  Each image data acquired by the image data acquisition unit 110 is stored in the storage unit 122 of the control device 120, and the control unit 121 is formed in the unit storage area UA from each image data stored in the storage unit 122. The unit data (unit bit string) is read based on the unit data pattern 31, and the position information of the unit storage area UA is read based on the address pattern 4, and the unit data (unit bit string) and the position information are stored in association with each other. Stored in the unit 122.

  When reading unit data (unit bit string) based on the unit data pattern 31, the control unit 121 defines a virtual grid Gr on the image data including the unit storage area UA and the boundary pattern 5. The virtual grid Gr is defined so as to pass through the reference point Cp of the boundary pattern 5 located at four corners. And the control part 121 determines whether the recessed part 311 exists on each intersection PI of the virtual grid Gr in the unit storage area UA. The determination of whether or not the recess 311 exists can be made based on, for example, a light / dark distribution in the image data.

  The control unit 121 associates bit “1” with the intersection point PI determined to have the recess 311 and associates bit “0” with the intersection point PI determined to have no recess 311, thereby generating unit data (unit bit string). Is read out.

  When reading the unit data (unit bit string) based on the unit data pattern 31, the control unit 121 recognizes the boundary pattern 5 located at the upper left in the image data, uses the reference point Cp of the boundary pattern 5 as an index, Judgment is made on whether or not the concave portion 311 exists in the right direction from the intersection point PI of the virtual grid Gr located in the lower direction and in the unit storage area UA.

  When the control unit 121 recognizes the discrimination pattern 33 while reading the unit data (unit bit string) based on the unit pattern data 31 from each image data, the control unit 121 determines that the uneven structure after the discrimination pattern 33 is the dummy pattern 32. , Reading of unit data (unit bit string) is stopped.

  Thereafter, the control unit 121 combines the unit data (unit bit string) stored in the storage unit 122 to generate data (bit string).

  In generating the data (bit string), the control unit 121 determines the combination order of the unit data (unit bit string) based on the position information stored in association with the unit data (unit bit string). Specifically, the control unit 121 combines the unit data (unit bit string) in ascending order of the row number and the column number with the row number as the position information as the first priority and the column number as the second priority. In this way, data stored in the data storage medium 1 can be restored.

  As described above, according to the data reading apparatus and the data reading method in the present embodiment, by recognizing the discrimination pattern 33, the data based on the dummy pattern 32 is not read, and the unit based on the unit pattern data 31 is recognized. Since only the data can be read, the data stored in the data storage medium 1 can be accurately restored.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  In the above embodiment, the data storage medium 1 includes the unit data pattern 31 and the dummy pattern on the first surface 11 of the substrate 10 for data storage medium made of quartz, which has the first surface 11 and the second surface 12 opposite to the first surface 11. 32, the discrimination pattern 33, the address pattern 4 and the boundary pattern 5 are formed simultaneously (see FIG. 10), but the present invention is not limited to such an embodiment. For example, as shown in FIG. 13, a plurality of unit storage areas UA and data are provided on a first surface 11 ′ of a quartz substrate 10 ′ having a first surface 11 ′ and a second surface 12 ′ opposite thereto. A data storage medium in which a storage area SA including a non-storage area NA is set, and an address pattern 4 and a boundary pattern 5 corresponding to each unit storage area UA are formed in the data non-storage area NA of the storage area SA. The data storage medium 1 may be manufactured by preparing and simultaneously forming the unit data pattern 31, the dummy pattern 32, and the discrimination pattern 33 in each unit storage area UA of the data storage medium.

In the above-described embodiment, the mode in which the resist patterns R ₃₁ , R ₃₂ , R ₃₃ , R ₄ , and R ₅ are formed using a positive type energy beam sensitive resist material has been described as an example (see FIG. 10). The present invention is not limited to such an embodiment, and a resist pattern may be formed using a negative type energy ray sensitive resist material. As a result, the data storage medium 1 having the unit data pattern 31, the dummy pattern 32, the discrimination pattern 33, and the address pattern 4 as convex portions (pillars) and portions having no convex portions and the boundary pattern 5 as convex portions (pillars) is provided. Can be produced.

In the above embodiment, it calculates the area density AD _UP unit pattern data D ₃₁ in the area other than the dummy pattern data generation region (a region where the unit data pattern 31 in the storage area SA is formed), the area density AD _UP the has been described by way of example the manner of generating the dummy pattern data D ₃₂ as an index, the present invention is not limited to such a mode. For example, after extracting the dummy pattern data generation area, the area density AD _UP of the unit pattern data D _{31 in} the area corresponding to the unit storage area surrounding the area is calculated, and the area density AD _UP is used as an index to calculate the dummy pattern data generation area. A graphic cell corresponding to the dummy pattern 32 may be arranged in the pattern data generation area. For example, with reference to FIG. 3, since the area corresponding to the unit storage area UA14 (part of UA14) to UA16 is a dummy pattern data generation area, the unit storage areas UA7 to UA11 surrounding the area. , UA13, UA17, as an index area density AD _UP unit pattern data D ₃₁ in the region corresponding to the UA19～UA23, graphic cell corresponding to the dummy pattern 32 is disposed. The area density of the unit data pattern 31 is usually different for each of the plurality of unit storage areas in the storage area SA. For example, even if the area density of the unit data pattern 31 in the entire storage area SA is 15%, the area density of the unit data pattern 31 around the dummy area DMA may be 10% or 20%. is there. Therefore, even if the dummy pattern 32 is formed in the dummy area DMA with an area density of 15% using the area density of the unit data pattern 31 in the entire storage area SA as an index, the area density of the unit data pattern 31 around the dummy area DMA is In the case of 10%, the difference in area density between the dummy area DMA and the data area DTA becomes large. When a replica is produced by imprint processing using such a data storage medium 1, stress at the time of peeling increases at the boundary between the data area DTA and the dummy area DMA, and there is a possibility that a defect occurs. However, by making the area density of the unit data pattern 31 in the unit storage area around the dummy area DMA substantially the same as the area density of the dummy pattern 32 in the dummy area DMA, the data area DTA and the dummy area DMA The stress at the time of peeling at the boundary of the film can be reduced, and a duplicate by imprint processing can be produced with high accuracy.

The extracts dummy pattern data generation region, after calculating the areal density AD _UP unit pattern data D31 of each unit storage area UA in the storage area SA, the extracted region centered, in the storage area SA The gradient of the change in the area density AD _UP is calculated, the area density of the dummy pattern 32 in the dummy region DMA is obtained using the gradient as an index, and the graphic cell corresponding to the dummy pattern 32 is determined based on the area density of the dummy pattern 32 May be arranged. By forming the dummy pattern 32 in such a manner, a change in stress applied to the entire storage area SA during peeling can be reduced, so that a duplicate by imprint processing can be manufactured with high accuracy.

DESCRIPTION OF SYMBOLS 1 ... Data storage medium 2 ... Base material 21 ... 1st surface 22 ... 2nd surface 31 ... Unit data pattern 32 ... Dummy pattern 33 ... Discrimination pattern 4 ... Address pattern 5 ... Boundary pattern SA ... Storage area UA ... Unit storage area NA ... Data non-storage area Gr ... Virtual grid PI ... Intersection

Claims (14)

A method of manufacturing a data storage medium in which data is stored,
Pattern data generation for generating pattern data used when forming a concavo-convex structure on the first surface side of the substrate for a data storage medium made of quartz having a first surface and a second surface opposite to the first surface Process,
A concavo-convex structure forming step of forming the concavo-convex structure on the first surface of the base material for the data storage medium based on the pattern data;
The concavo-convex structure is formed in a data area in a storage area defined on the first surface side of the data storage medium base material, and a data concavo-convex structure expressing the data content of the data, and in the storage area Including a dummy concavo-convex structure formed in a dummy area which is an area other than the data area in
The pattern data generation step includes adding a first step of generating first pattern data corresponding to the data uneven structure and second pattern data corresponding to the dummy uneven structure to the first pattern data. A second step of generating pattern data,
In the second step, adding the second pattern data to the first pattern data based on the first pattern data so that an area density of the concavo-convex structure in the storage region is substantially uniform. A method for manufacturing a data storage medium. In the pattern data generation step, set a pattern data generation area corresponding to the storage area,
In the first step, a first graphic cell corresponding to the data concavo-convex structure is arranged in the pattern data generation region to generate the first pattern data,
The second step is a step of extracting, as the first pattern data generation region, a region where the first graphic cell is arranged in the pattern data generation region based on the first pattern data, and the first pattern data generation region Extracting a region other than the second pattern data generation region corresponding to the dummy region, and arranging the second graphic cell corresponding to the dummy concavo-convex structure in the second pattern data generation region to form the second pattern data The method for producing a data storage medium according to claim 1, further comprising a step of generating the data. The storage area includes a plurality of unit storage areas arranged in a matrix,
The data concavo-convex structure is composed of a plurality of unit data concavo-convex structures expressing the data contents of each of a plurality of unit data obtained by dividing the data,
In the pattern data generation step, set a plurality of unit pattern data generation areas corresponding to each of the plurality of unit storage areas,
In the first step, the first graphic cells corresponding to the unit data concavo-convex structures are arranged in the unit pattern data generation areas in the matrix arrangement order of the plurality of unit pattern data generation areas, and the first pattern data is arranged. Generate
The second step is a step of extracting, as the first pattern data generation region, a region where the first graphic cell is arranged in each of the plurality of unit pattern data generation regions based on the first pattern data. Extracting a region other than the pattern data generation region as a second pattern data generation region corresponding to the dummy region; and disposing a second graphic cell corresponding to the dummy concavo-convex structure in the second pattern data generation region The method of manufacturing a data storage medium according to claim 1, further comprising a step of generating second pattern data.   In the step of generating the second pattern data, a ratio of a total area of the first graphic cell to a total area of the first pattern data generation region in which the first graphic cell is arranged is based on the first pattern data. Calculating and generating the second pattern data by arranging the second graphic cells in the second pattern data generation region at an area ratio substantially the same as the ratio of the total area of the first graphic cells. A method for manufacturing a data storage medium according to claim 3.   In the step of generating the second pattern data, the unit pattern data generation area located around the second pattern data generation area is extracted based on the first pattern data, and the extracted unit pattern data generation area The ratio of the total area of the first graphic cell to the total area is calculated, and the second graphic cell is placed in the second pattern data generation region at an area ratio substantially the same as the ratio of the total area of the first graphic cell. 4. The method of manufacturing a data storage medium according to claim 3, wherein the second pattern data is generated by arranging the data.   In the step of generating the second pattern data, from the ratio of the total area of the first graphic cells in the unit pattern data generation region located around the second pattern data generation region, the unit pattern data generation region A gradient of the ratio of the total area of the first graphic cell is calculated, and the second graphic cell is arranged in the second pattern data generation region based on the gradient of the ratio of the total area of the first graphic cell. 6. The method of manufacturing a data storage medium according to claim 5, wherein two pattern data is generated. The uneven structure further includes a determination uneven structure for determining a boundary between the data uneven structure and the dummy uneven structure,
The pattern data generation step further includes a step of adding third pattern data corresponding to the determination uneven structure to the first pattern data generated in the first step,
7. The data storage medium manufacturing according to claim 1, wherein in the second step, the second pattern data is added to the first pattern data to which the third pattern data is added. Method.   The method for manufacturing a data storage medium according to claim 1, wherein the data uneven structure and the dummy uneven structure have substantially the same dimensions. A data storage medium in which data is stored,
A base material made of quartz having a first surface and a second surface opposite to the first surface;
A concavo-convex structure formed in a storage region set on the first surface of the base material,
The storage area includes a plurality of unit storage areas arranged in parallel in at least one direction, and a data non-storage area located between the adjacent unit storage areas,
The concavo-convex structure is formed in a data pattern expressing the data content of the data, formed in a data area in the unit storage area, and in a dummy area which is an area other than the data area in the unit storage area. A dummy pattern formed in the unit storage area, and a determination pattern for determining a boundary between the data pattern and the dummy pattern,
Each of the data pattern and the dummy pattern is formed in each of the data region and the dummy region so that an area density of the concavo-convex structure in the storage region is substantially uniform. Data storage medium. The data pattern and the dummy pattern have substantially the same shape and dimensions as each other,
The data storage medium according to claim 9, wherein the discrimination pattern has a shape and a size different from those of the data pattern and the dummy pattern. An apparatus for reading data stored in the data storage medium according to claim 9 or 10,
An image data acquisition unit for acquiring image data including the storage area;
A data reading unit that extracts the data pattern of the concavo-convex structure formed in the storage area from the image data, and reads the data based on the extracted data pattern ; Data reading device. Before Symbol data reading unit as an indicator the Determination pattern, wherein the image data, the data reading device according to claim 11, characterized in that to extract the data pattern of said convex-concave structure. A method for reading data stored in a data storage medium according to claim 9 or 10,
An image data acquisition step of acquiring image data including the storage area;
A data reading step of extracting the data pattern of the concavo-convex structure formed in the storage area from the image data and reading the data based on the extracted data pattern. Data reading method. Before Symbol data reading process, as an index the Determination pattern, from the image data, the data reading method according to claim 13, characterized in that to extract the data pattern of said convex-concave structure.

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