JP2000235632A - Digital information recording carrier, digital information recording method/device and digital information decoding method/device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a reading error on a whole area even if the area of an information area is enlarged and to increase storage capacity by constituting a system of a center close area and a circular part which continuously surrounds the periphery of the area and is formed of the specified number of squares to which black is given as a mark. SOLUTION: In a recording face 20, plural specified patterns 22 where black/ white are given to plural squares connected in a specified form with, the specified patterns are arranged in the gaps of areas 21 showing original recording information in an information recording area 23 where information is actually recorded. Namely, 10 specified patterns 22 pertaining to an uppermost stage, the lowermost stage, a left stage and a right stage in an array are arranged along the outer periphery of the information recording area 23. Two remaining specified patterns 22 are arranged in a center close area detached from the outer periphery of the information recording area 23. When the specified patterns 22 are thus arranged, digital information can precisely be read even if distortion slightly exists in the recording face 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital information recording carrier for recording digital information on a recording surface as a two-dimensional pattern. Further, the present invention relates to a digital information recording method and apparatus capable of producing such a digital information record carrier. The present invention also relates to a digital information decoding method and apparatus capable of reading and decoding digital information recorded on such a digital information recording carrier.

[0002]

2. Description of the Related Art As a method of recording digital information by arranging a matrix two-dimensionally on a recording surface, for example, a two-dimensional data code as shown in FIG.
No. 2-012579). The two-dimensional data code is for virtually setting a matrix in a matrix corresponding to a bit on a recording surface 220 of a record carrier, and recording digital information with white or black representing data in each of the cells. It is.

In general, in such a recording method, an information recording area 219 is provided on a recording surface 220 for convenience of reading.
And control information indicating the size of the cells and the size (data density) of the cells. In the example of FIG. 50, as the control information, a straight line portion 212 formed by connecting black meshes to two adjacent sides 221 of the outer periphery of the rectangular information recording area 219 is provided, and a white part is formed on the remaining two sides 231. A clocking information section 216 is provided in which the cells and the black cells are alternately connected. At the time of reading, the direction of the information recording area 219 is detected by the linear part 212, and the size of the mesh is detected by the clocking information part 216.

[0004]

However, in the conventional digital information recording system, the clocking information section 2
Since the area 16 is provided along the outer periphery of the information recording area 219, the distance between the clocking information section 216 and the data increases as the area of the information recording area 219 increases. Therefore, near the center of the information recording area 219, the recording surface 22
Due to the distortion of 0 and the characteristics of the reading device (scanner, CCD camera, etc.), the deviation between the data position at the time of recording and at the time of reading becomes large, and a reading error may occur. For example, when the information on the cell in the fifth row and the fourth column is to be read, the information in the sixth row and the fifth column is incorrectly read. For this reason, in the conventional digital information recording method,
There is a problem that the storage capacity cannot be increased by increasing the area of the information recording area 219.

Accordingly, an object of the present invention is to provide a digital information recording carrier capable of preventing a reading error from occurring in the entire information recording area even if the area of the information recording area is increased, and thus increasing the storage capacity. To provide. Another object of the present invention is to provide a digital information recording method and apparatus capable of producing such a digital information record carrier. Another object of the present invention is to provide a digital information decoding method and apparatus capable of reading and decoding digital information recorded on such a digital information recording carrier.

[0006]

According to a first aspect of the present invention, there is provided a digital information recording medium comprising: a digital information recording carrier having a matrix-like structure corresponding to bits in an information recording area provided in a planar recording surface; A cell is virtually set, and an optically recognizable mark corresponding to the digital information to be recorded is given to each cell, and the digital information to be recorded is recorded on a digital information recording carrier recorded as a two-dimensional pattern. In the information recording area, a specific pattern in which the mark is provided in a predetermined pattern on a plurality of cells connected to a specific shape is arranged, and the cells have the same shape. The specific pattern includes a central closed area composed of four meshes with light as the mark, and a continuous area surrounding the central closed area, and twelve meshes with darkness as the mark. From It is characterized by comprising an annular portion that.

According to a second aspect of the present invention, there is provided a digital information recording carrier, wherein a matrix in the form of a matrix corresponding to bits is virtually set in an information recording area provided in a planar recording surface,
A digital information recording carrier in which each of the cells is provided with an optically recognizable mark corresponding to the digital information to be recorded, and the digital information to be recorded is recorded as a two-dimensional pattern. In addition, a specific pattern in which the mark is applied in a predetermined pattern to a plurality of cells connected to a specific shape is arranged, and each of the cells has the same shape. A central portion made up of one mesh with darkness, a first annular portion made up of eight meshes surrounding the central portion in succession, and being lighted as the mark; 1
The present invention is characterized in that it comprises a second annular portion which surrounds the periphery of the annular portion in succession and is made up of 16 meshes which are shaded as the mark.

According to a third aspect of the present invention, there is provided the digital information recording carrier according to the first or second aspect, wherein a plurality of the specific patterns are dispersedly arranged over the entire information recording area. It is characterized by having.

According to a fourth aspect of the present invention, there is provided a digital information recording carrier according to any one of the first to third aspects, wherein the specific pattern is located inside the information recording area. Thus, it is characterized by being arranged at high density around the information recording area.

According to a fifth aspect of the present invention, there is provided a digital information recording carrier according to any one of the first to third aspects, wherein the specific pattern has a smaller size than a peripheral portion of the information recording area. Further, it is characterized in that it is arranged at a high density inside the information recording area.

According to a sixth aspect of the present invention, there is provided a digital information recording carrier according to any one of the first to fifth aspects, wherein the information recording area is a rectangular area. The specific pattern is arranged at a corner of the recording area.

According to a seventh aspect of the present invention, in the digital information record carrier according to the sixth aspect, the specific pattern arranged in the corner is another specific pattern arranged in the information recording area. The feature is that the shape and the brightness are different from the pattern.

The digital information record carrier according to claim 8 is the digital information record carrier according to claim 6 or 7, wherein a part of the specific pattern arranged at the corner is a part of the specific pattern at this corner. The shape and brightness of the remaining specific patterns arranged in the corners are different so that the set is asymmetric with respect to the rotation of 90 °, 180 ° or 270 ° in the plane of the recording surface. It is characterized by.

According to a ninth aspect of the present invention, there is provided a digital information recording carrier according to any one of the first to eighth aspects, wherein the information recording area has a constant brightness as the mark in the information recording area. The present invention is characterized in that a specific pattern and a specific pattern obtained by inverting the brightness of the specific pattern so as to have a contrast with the surrounding cells representing the original recording information are arranged.

In the digital information recording method according to the tenth aspect, a matrix in a matrix corresponding to bits is virtually set in an information recording area provided in a planar recording surface,
A digital information recording method in which an optically recognizable mark corresponding to digital information to be recorded is provided in each of the cells, and the digital information to be recorded is recorded as a two-dimensional pattern. A specific pattern in which the mark is provided in a predetermined pattern on a plurality of cells connected to a specific shape is arranged inside the space separated from the outer periphery, and an area of the information recording area where the specific pattern is to be arranged. It is characterized in that digital information to be originally recorded is recorded in an area other than.

The digital information recording method according to claim 11 is the digital information recording method according to claim 10, wherein the digital information is recorded in an area of the information recording area other than the area where the specific pattern is to be arranged. After recording the digital information to be recorded, the brightness of the mesh around the area where the specific pattern is to be arranged is compared with the brightness of the portion of the specific pattern adjacent to the surrounding mesh, and compared. When the lightness and darkness match, a specific pattern obtained by reversing the lightness and darkness of the specific pattern is arranged in the area where the specific pattern is to be arranged, instead of the specific pattern.

According to a twelfth aspect of the present invention, there is provided a digital information decryption method for decrypting information recorded on a digital information recording carrier according to any one of the first to ninth aspects, The specific pattern is searched for in the information recording area to determine its position, and based on the positions of four specific patterns located in specific two rows and two columns in the searched specific pattern, original information is obtained. Calculating the position of an arbitrary cell in which is recorded by proportional distribution, reading the bit information represented by the cell at the calculated position, and reproducing the digital information recorded on the recording surface based on the bit information. Features.

According to a thirteenth aspect of the present invention, in the digital information decoding method according to the twelfth aspect, when the specific pattern according to the first aspect is searched for in the information recording area, Examining the brightness of the reference position where the center closed region of the pattern should exist, and determining that the reference position is included in the center closed region when the brightness of the reference position is bright; and Checking whether the area, width and height of this area are within a certain range, respectively, for the area including the connected lights, and confirming that this area is the central closed area, It is characterized in that a specific pattern is recognized.

According to a fourteenth aspect of the present invention, in the digital information decrypting method according to the twelfth aspect, when the specific pattern according to the second aspect is searched for in the information recording area, Examining the brightness of the reference position where the center should be located, and determining that the reference position is included in the center when the reference position is dark; Checking whether the area, width, and height of this area are within certain ranges, and confirming that this area is the central part. A step of confirming that the bright region is the first annular portion when a dark region appears within a certain distance in any of the upper, lower, left, and right directions and when the circuit has made a round along the boundary between the bright region and the dark region. By, it is characterized in that it has to recognize the specific pattern.

According to a fifteenth aspect of the present invention, there is provided a digital information recording apparatus, wherein cells in a matrix corresponding to bits are virtually set in an information recording area provided in a planar recording surface, and the cells are recorded in the cells. A digital information recording apparatus for recording an optically recognizable mark corresponding to digital information to be recorded and recording the digital information to be recorded as a two-dimensional pattern, for inputting the digital information to be recorded. Input means, and a specific pattern formed by attaching the mark in a predetermined pattern to a plurality of cells connected to a specific shape in an interior separated from the outer periphery of the information recording area, and the information recording area A pattern in which digital information to be originally recorded is arranged in an area other than an area in which the specific pattern is to be arranged, and a two-dimensional pattern to be printed on the recording surface is generated. And forming means is characterized by comprising a printing means for printing on the recording surface a two-dimensional pattern generated by said pattern generating means.

A digital information decrypting device according to a sixteenth aspect is a digital information decrypting device for reading and decrypting digital information from a digital information recording carrier according to any one of the first to ninth aspects. 2 recorded on the surface
Reading means for reading a two-dimensional pattern and outputting information representing the two-dimensional pattern; and searching for the specific pattern in the two-dimensional pattern represented by the output information of the reading means to determine the position of the specific pattern. Among them, based on the positions of four specific patterns located in specific two rows and two columns, the position of an arbitrary cell where original information is recorded is calculated by proportional distribution, and the cell at the calculated position is calculated. And information output means for reading the bit information represented by the symbol information and reproducing the digital information recorded on the recording surface based on the bit information, and outputting the digital information reproduced by the information decoding means. And

Hereinafter, the operation of the present invention will be described.

In the digital information recording carrier according to the first aspect, since the specific pattern is arranged in the information recording area, even if the vicinity of the center of the information recording area is distorted, the information recording is performed based on the position of the specific pattern. The position of the mesh in the vicinity of the center of the area can be obtained with high accuracy. Therefore, even if the area of the information recording area is increased, no reading error occurs near the center of the information recording area. Further, in the peripheral portion of the information recording area, the occurrence of a reading error is prevented by providing clocking information or providing the specific pattern as in the related art. Therefore, it is possible to increase the area of the information recording area and increase the storage capacity. In addition, the specific pattern includes a central closed area composed of four meshes with light as the mark, and a continuous area surrounding the central closed area, and twelve squares with darkness as the mark. It consists of an annular part consisting of eyes. Therefore, it becomes easy to find a specific pattern in the information recording area. In addition, the number of cells constituting the specific pattern is relatively small. Further, when the same or similar pattern appears in the vicinity as the original recording information, the specific pattern is unlikely to overlap the pattern. Further, the specific pattern is less susceptible to effects such as stains during printing and ink bleeding. Also, the algorithm for finding a specific pattern is simplified.

According to the digital information recording carrier of the present invention, since the specific pattern is arranged in the information recording area, even if the vicinity of the center of the information recording area is distorted, the information recording is performed based on the position of the specific pattern. The position of the mesh in the vicinity of the center of the area can be obtained with high accuracy. Therefore, even if the area of the information recording area is increased, no reading error occurs near the center of the information recording area. Further, in the peripheral portion of the information recording area, the occurrence of a reading error is prevented by providing clocking information or providing the specific pattern as in the related art. Therefore, it is possible to increase the area of the information recording area and increase the storage capacity. In addition, the specific pattern includes a central portion composed of one mesh with darkness as the mark, and a continuous area surrounding the central portion, and eight meshes with light as the mark. And a second annular portion comprising 16 meshes which surround the first annular portion in a continuous manner, and are darkened as the mark. Therefore, similarly to the first aspect, it becomes easy to find the specific pattern in the information recording area. In addition, the number of cells constituting the specific pattern is relatively small. Further, when the same or similar pattern appears in the vicinity as the original recording information, the specific pattern is unlikely to overlap the pattern. Further, the specific pattern is less susceptible to effects such as stains during printing and ink bleeding. Also, the algorithm for finding a specific pattern is simplified.

In the digital information recording carrier according to the third aspect, since the plurality of specific patterns are arranged dispersedly over the entire area of the information recording area, the position of an arbitrary cell can be accurately determined over the entire area of the information recording area. Well sought. Therefore, it is possible to increase the area of the information recording area and increase the storage capacity.

In the digital information recording carrier according to the present invention, the specific pattern is arranged at a higher density in the periphery of the information recording area than in the information recording area. The reading accuracy of the peripheral portion where distortion easily occurs is increased, and the occurrence of a reading error is prevented.

[0027] In the digital information recording carrier according to the fifth aspect, the specific pattern is arranged at a higher density inside the information recording area than at a peripheral portion of the information recording area. The reading accuracy near the center is improved, and the occurrence of a reading error is prevented.

In the digital information record carrier of the present invention, the information recording area is a rectangular area, and the specific pattern is arranged at a corner of the information recording area. Thus, the range occupied by the information recording area on the recording surface can be easily determined.

According to the digital information recording carrier of the present invention, the specific pattern arranged in the corner has a different shape or lightness and darkness from other specific patterns arranged in the information recording area. By searching for a specific pattern, the range occupied by the information recording area on the recording surface can be easily determined.

In the digital information record carrier according to the present invention, a part of the specific patterns arranged at the corners may be such that the set of specific patterns at the corners is 90 ° or 180 ° within the recording surface.
Alternatively, since the shape and brightness are different from the remaining specific patterns arranged in the corners so as to be asymmetric with respect to the rotation of 270 °, the top and bottom and right and left of the information recording area can be easily recognized.

In the digital information record carrier according to the ninth aspect, the specific pattern having a constant brightness as the mark in the information recording area and the specific pattern so as to have a contrast with surrounding meshes representing the original recording information. Since the specific pattern obtained by inverting the brightness of the specific pattern is arranged, the boundary between the specific pattern and the surrounding cells representing the original recording information can be easily recognized. As a result, each specific pattern is easily searched.

According to the digital information recording method of the tenth aspect, the digital information recording carrier of the first to ninth aspects can be easily created.

According to the digital information recording method of the present invention, the boundary between the specific pattern and the surrounding mesh representing the original recording information can be easily recognized on the recording surface of the digital information recording carrier. As a result, each specific pattern is easily searched.

According to the digital information decoding method of the twelfth aspect, the digital information recorded on the recording surface of the digital information recording carrier of the first to ninth aspects can be easily reproduced.

According to the digital information decoding method of claim 13, when searching for the specific pattern described in claim 1 in the information recording area, the specific pattern is easily and easily recognized.

According to the digital information decoding method of claim 14, when searching for the specific pattern according to claim 2 in the information recording area, the specific pattern is easily and easily recognized.

According to the digital information recording apparatus of the present invention, first, the input means inputs the digital information to be recorded. Next, the pattern generation means arranges a specific pattern in which the mark is attached in a predetermined pattern to a plurality of cells connected to a specific shape inside the information recording area separated from the outer periphery of the information recording area, and Digital information to be originally recorded is arranged in an area other than the area where the specific pattern is to be arranged, and a two-dimensional pattern to be printed on the recording surface is generated. Then, the printing unit prints the two-dimensional pattern generated by the pattern generation unit on a recording surface. Therefore, the digital information record carrier of claims 1 to 9 can be easily produced.

According to the digital information decoding apparatus of the present invention, first, the reading means reads the two-dimensional pattern recorded on the recording surface of the digital information recording carrier, and outputs information representing the two-dimensional pattern. Next, the information decoding means searches for the specific pattern in the two-dimensional pattern represented by the output information of the reading means to find its position, and locates the position in specific two rows and two columns in the searched specific pattern. Based on the positions of the four specific patterns, the position of an arbitrary cell on which the original information is recorded is calculated by proportional distribution, and the bit information represented by the cell at the calculated position is read. To reproduce the digital information recorded on the recording surface. Then, the output means outputs the digital information reproduced by the information decoding means. Therefore, the digital information recorded on the digital information record carrier according to claims 1 to 9 can be easily decoded.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments.

(1) Basic Configuration of Digital Information Record Carrier FIG. 1 shows an embodiment of a digital information record carrier according to one embodiment of the present invention, and FIG. 2 schematically shows this record carrier.

On the recording surface 20 of the digital information recording carrier, a matrix of squares in a matrix corresponding to the bits of the digital information is virtually set. White (bright) representing “0” or black (dark) representing “1” is added (black is indicated by hatching for convenience). Thus, digital information is recorded on the recording surface 20 as a two-dimensional pattern.

In the information recording area 23 where the information is actually recorded on the recording surface 20, a plurality of meshes connected to a specific shape are provided in a gap between the areas 21 representing the original recording information. Specific pattern 22 with black and white in the pattern
Are arranged. In this example, a total of 12 specific patterns 2 (vertical 4 × horizontal 3) are stored in the rectangular information recording area 23.
2 are arranged in a matrix at regular intervals in the vertical and horizontal directions. As can be clearly understood from FIG. 2, ten specific patterns 22 belonging to the uppermost row, the lowermost row, the left column, and the right column in the arrangement of the specific patterns 22 are arranged along the outer periphery of the information recording area 23, and the remaining two The specific pattern 22 is disposed inside (near the center) separated from the outer periphery of the information recording area 23. In this example, the specific pattern 22B shown in FIG. 7 is employed as the specific pattern 22 (the specific pattern itself will be described later in detail).

As described above, when the specific pattern 22 is arranged inside the information recording area 23 at a distance from the outer periphery, when reading the recorded digital information, even if the recording surface 20 is slightly distorted, Digital information can be read accurately.

For example, as shown in FIG. 3B, the clocking information 3 is provided along the outer circumference of the information recording area 23 as in the prior art.
When the recording surface 20 is distorted only by providing 1,
For example, the information of the cells in the fifth row and the fourth column is to be read inside the information recording area 23 apart from the outer periphery, but the information of the cells in the sixth row and the fifth column may be erroneously read. On the other hand, when the specific pattern 22 is arranged inside the information recording area 23 at a distance from the outer periphery as described above, even if the recording surface 20 is distorted as shown in FIG. According to the distortion, the specific pattern 22 moves from the original position 53 to the position 54, for example. Therefore, when information of a certain cell (which originally exists at the position 55) is read, the actual position 56 of that cell is known based on the movement amount 51 (shown by an arrow in the figure) of the specific pattern 22 in the vicinity. be able to. Therefore, it is possible to accurately read the information recorded in the grid.

The problem here is the difference between the movement amount 52 of the cell to be read and the movement amount 51 of the specific pattern 22 in the vicinity thereof. This difference is large (for example, this difference is 1
A reading error occurs when the number of cells exceeds the number of cells. However, such a reading error is reduced by narrowing the interval between the specific patterns 22 and 22 so that the cell to be read and the specific pattern are close to each other. be able to.

Conversely, based on the movement amount of the specific pattern 22, the interval between the specific patterns 22 should be set to be small enough to correct the positional deviation of the cell to be read. However, if the interval between the specific patterns 22 is too narrow, the number of the specific patterns 22 occupying the information recording area 23 becomes too large, and the amount of information that can be recorded is reduced. Therefore, from both viewpoints, the interval between the specific patterns 22, 22 is set to an appropriate value.

When trying to read information from this information record carrier using, for example, a line sensor or a CCD camera,
Distortions tend to occur at both ends of the line sensor and at the periphery of the field of view of the CCD camera. In such a case, as shown in FIG. 4, specific patterns are arranged at high density around the information recording area 23. That is, according to the characteristics of the reading device,
The specific patterns 22 are arranged at a high density where relatively large read distortion is likely to occur. This allows
Reading errors can be reduced.

Conversely, as shown in FIG. 5, when the specific pattern 22 is arranged inside the information recording area 23 and the clocking information 31 is provided around the information recording area 23, the specific pattern 22 The complementary role of clocking information 31 is expected. Therefore, it is desirable to arrange the specific patterns 22 at a high density in a portion where an error easily occurs in reading based on only the clocking information 31, that is, in the center of the information recording area 23.

In these cases, the specific patterns 22, 22
The vertical interval and the horizontal interval between them may be the same or different.

However, when the interval between the specific patterns 22 is changed in the information recording area 23, the position of the specific pattern 22 must be known in advance when reading, or the first stage of the reading process can be performed. Need to be available at In order to know the arrangement of the specific pattern 22 at the first stage of the reading process, for example, the arrangement of the uppermost specific pattern 22 is determined. What is necessary is just to be able to read information.

When the decoding device knows the arrangement of the specific pattern 22 in advance, the specific pattern 22 does not need to be in contact with the outer periphery of the information recording area 23, and the specific pattern 22 is arranged in a grid. You don't have to be. The specific pattern 22 can be freely arranged.

(2) Preferable Examples of Specific Patterns The following conditions are required to be satisfied for the specific pattern 22 to be preferable. That is, it has features (specific black-and-white patterns) that can be easily found in the information recording area 23, the number of constituent cells is relatively small, and the same or similar patterns appear as original recording information in the vicinity. In this case, it is difficult to overlap with the pattern that appears, it is hard to be affected by stains or bleeding of ink at the time of printing, and the algorithm for finding is simple.

FIG. 6 shows a preferred example 22 of the specific pattern 22.
A is shown. This specific pattern 22A has a central closed area 44 composed of four cells of 2 rows × 2 columns with white.
And an annular portion 45 composed of twelve black cells surrounding the periphery in a ring shape. The whole is a square block including a total of 16 cells of 4 rows × 4 columns.

FIG. 7 shows another preferred example 22 B of the specific pattern 22. The specific pattern 22B includes a central portion 41 composed of one black-colored mesh, a first annular portion 42 composed of eight white-colored meshes surrounding the periphery in a ring shape, and The second annular portion 43 is composed of 16 black cells surrounding the periphery in a ring shape. The whole is a square block including a total of 25 cells of 5 rows × 5 columns.

FIGS. 8A to 8G show various examples 22C to 22I of the specific pattern 22. FIG.

The specific pattern 22C shown in FIG. 9A has a central portion composed of a single black cell and an annular cell composed of eight white cells surrounding the cell in a circular shape. It is composed of a part and a part. The whole is a square block including a total of 9 meshes of 3 rows × 3 columns.

The specific pattern 22D shown in FIG.
Is a square block including a total of 25 cells of 5 rows × 5 columns, and the cells in the block are alternately colored black and white to form a checkered pattern.

The specific pattern 22E shown in FIG.
Is a square block including a total of 25 cells of 5 rows × 5 columns, and the diagonal cells in the block are colored black to form an X-shaped pattern.

The specific pattern 22F shown in FIG.
Is a closed central area consisting of 9 cells in 3 rows x 3 columns with white and black with 16 surrounding the periphery in a ring.
And an annular portion composed of individual meshes. The whole is a square block including a total of 25 cells of 5 rows × 5 columns.

The specific pattern 22G shown in FIG.
Is obtained by removing the mesh at the center of each of the upper, lower, left and right sides in the specific pattern 22E shown in FIG.

The specific pattern 22H shown in FIG.
Is a square block including a total of 35 meshes of 5 rows × 7 columns, and the meshes in black in the block have an S-shaped pattern.

The specific pattern 22I shown in FIG.
Is composed of a central portion made up of a single white mesh and an annular portion made up of eight black meshes surrounding the periphery in a ring shape. The whole is a square block including a total of 9 meshes of 3 rows × 3 columns.

As described above, various patterns can be adopted as the specific pattern 22, but the specific patterns 22A and 22B shown in FIGS. 6 and 7 are more preferable than the other specific patterns 22C to 22I. The reason will be described in the following (i) to (v) in relation to the above conditions (1) to (5).

(I) First, there is an advantage that it is relatively easy to extract the specific patterns 22A and 22B from the information recording area 23. The checkerboard specific pattern 22D as shown in FIG. 8B is buried in the information recording area 23 and cannot be found.
A and 22B can be recognized by the naked eye, for example. In particular,
When it is known in advance that the specific patterns 22A and 22B are arranged in a grid pattern, it can be more easily found.

(Ii) Second, specific patterns 22A, 22
The number of cells constituting B is 16 in the specific pattern 22A.
There is an advantage that the number of the individual patterns and the specific pattern 22B is relatively small as 25.

(Iii) Third, the specific patterns 22A, 2A
When the same pattern appears as the original recording information near 2B, there is an advantage that the specific pattern 22A or 22B and the pattern hardly overlap.

FIG. 9 shows an example in which, when the checkerboard specific pattern 22D shown in FIG. 8B is used, the same pattern appears as the original recording information in the vicinity thereof. In the case of this specific pattern 22D, the same pattern may appear at a position shifted by one square in the vertical direction and one square in the horizontal direction. When calculated as the length of one side of the cell, the minimum distance between the specific pattern 22D and the same pattern is 21/2.
Becomes

On the other hand, FIG.
In the case where A is used, an example in which the same pattern appears as original recording information in the vicinity thereof is shown. In the case of the specific pattern 22A, the same pattern can appear only at a position shifted by three grids vertically or horizontally. FIG. 11 shows an example in which when the specific pattern 22B is used, the same pattern appears near the specific pattern 22B as the original recording information. In the case of the specific pattern 22B, the same pattern can appear only at a position shifted by four grids vertically or horizontally. In this way, the specific patterns 22A and 22B have relatively little overlap even if the same or similar pattern appears as the original recording information in the vicinity thereof, and the specific patterns 22A and 22B are displaced from each other to some extent. From this, the specific patterns 22A, 22B
Can be said to be a pattern that is relatively easy for the reader to distinguish from the original recorded information.

The handling when the specific pattern 22 and the same pattern overlap with each other will be described in detail in the section of the decoding method described later.

(Iv) Fourth, specific patterns 22A and 22
B has the advantage of being less susceptible to effects such as dirt and ink bleeding.

Generally speaking, in printing on paper, black meshes tend to spread due to ink bleeding and white meshes tend to be eroded. For example, in the specific pattern 22I shown in FIG. 8G, one white cell is surrounded by black cells, but the white cells tend to be crushed. As shown in FIG. 12, when the influence of ink bleeding is calculated on the assumption that each side of the black grid 47 spreads 1.4 times, the area of the white grid 46 at the center of the specific pattern 22I is normal. Only 36% of the time.

On the other hand, in the specific pattern 22A,
As shown in FIG. 13, the central closed area (four white squares) 44
Can secure 64% of the normal area. In the specific pattern 22B, as shown in FIG. 14, the first annular portion (8
The area of each of the white squares 42 can secure 60% of the normal area. In the case of the specific pattern 22A, as shown in FIG. 15, one of the four white cells constituting the central closed region 44 has been completely crushed by dirt or the like (it has been changed to a black cell). Even at this time, since the feature of “white closed area surrounded by a black frame” is retained, the influence of dirt can be avoided by adopting a reading method using this feature.

(V) Fifth, specific patterns 22A, 22
B has the advantage that the reading algorithm is simple.

As a general reading algorithm,
A method is used in which the size of a cell is determined and cut out from the recording surface, and the value of each cut-out cell (white or black in this example) is checked. Therefore, even when the specific pattern 22 is recognized, the cells constituting the specific pattern 22 are cut out,
A method of checking the values of all the meshes included in the specific pattern 22 can be considered.

On the other hand, a method of examining the specific pattern 22 without cutting out the cells may be considered. For example, in the case of the specific pattern 22B shown in FIG.
First, the central portion (black grid) 41 forms a closed region surrounded by white grids, and the first annular portion (white grid) 42 forms a closed region surrounded by black grids. You can find out by checking if there is. In the case of the specific pattern 22A shown in FIG. 6, the specific pattern 22A can be found by checking whether or not the central closed region 44 has an area for the fourth cell. The read portion is the specific pattern 2
It merely checks whether or not the features of 2A and 22B are matched, in other words, whether or not the necessary conditions of the specific pattern are satisfied, but not the value of each cell. However,
In practice, this method is sufficient, and even if another pattern is erroneously recognized as a specific pattern, for example, by extracting all the specific patterns, by checking whether each specific pattern is arranged in a grid pattern, Misrecognition can be ignored. In this case, it is also possible to perform a more accurate check only on a specific pattern that is considered to have a high possibility of erroneous recognition. Thus, the specific patterns 22A and 22B can be recognized by a simple algorithm.

As described above, the specific patterns 22A and 22B have many advantages as compared with the other specific patterns, and can be said to be preferable patterns.

(3) Recognition of Specific Pattern FIG. 16 shows an example of a processing flow for recognizing the specific pattern 22B shown in FIG.

The recognition process is performed on the bitmap data read from the reading device.

First, when the specific pattern 22B is arranged according to a predetermined arrangement in the information recording area 23, a position where the specific pattern 22B should appear in the bitmap data is predicted (S61). A position P serving as a search reference is determined in the map data (S6).
2). It is checked whether or not the dot at the reference position P is black (S63). If the dot is black, the process proceeds to step S66, assuming that the dot forms the central portion 41.

On the other hand, if the dot at the reference position P is not black in S63, the next search position is determined within a certain range from the reference position P (S64), and whether the dot at that search position is black again is determined. Find out. However, if all the search within the predetermined range from the reference position P is performed, but the black dot corresponding to the central portion 41 of the specific pattern 22B cannot be found (S65), the search fails (S76). And the process ends.

In step S66, a recursive search is made for black dots connected in the vertical, horizontal, and oblique directions to the dot at the reference position P. Then, it is determined whether or not the number of connected black dots is within a certain range (S67). If the number of connected black dots exceeds a certain number,
It is determined that the area where the black dots are connected is not closed, or even if it is closed, the area of the central portion 41 is too large. If the number of connected black dots is less than a certain number, it is determined that the noise is not the central portion 41 but merely noise. If the number of the connected black dots is not within the predetermined range, the process returns to S64 and the process is repeated.

On the other hand, if the number of connected black dots is within a certain range (S67), the process proceeds to S68, where the width and height of the connected region of the black dots are within a certain range. Is checked, and the shape of the area is checked. The width of the connected area is expressed by subtracting the minimum value from the maximum value of the X coordinate of the connected area, and the height of the connected area is expressed by subtracting the minimum value from the maximum value of the Y coordinate. You. If the width and height of the region where the black dots are connected are not within the predetermined range, the process returns to S64 and the process is repeated.

On the other hand, if the width and height of the area where the black dots are connected are within a certain range (S68), it is determined that the area where the black dots are connected is the central portion 41, and S
Go to 69.

Next, in S69, a check on the first annular portion 42 is started. One black dot (the one with the smallest Y coordinate) on the bottom surface of the connected area of the black dots determined to be the center portion 41 is selected (S69). Then, as shown by an arrow in FIG. 17, a search is performed downward from the area 41, and a black dot (second dot) that appears next to a white dot (considered as a white dot constituting the first annular portion 41) is obtained. (The black dots constituting the annular portion 42 are searched for) (S70). If the next black dot is not found within a certain distance from the white dot area, it is determined that the white dot area is not the first annular portion 42 of the specific pattern 22B (S71), and the process returns to S64. And repeat the process. On the other hand, when the next black dot is found within a certain distance from the white dot area (S71), it is considered that the black dot forms the second annular portion 43 of the specific pattern 22B. Then, as shown by the arrow in FIG.
Around the inner periphery of the region considered to be the annular portion 43, that is, along the boundary between the black dot and the white dot, by the left method (a method of following the wall of the maze while putting the left hand on the wall) (S7).
2). If you cannot make a round within a certain number of steps,
It is determined that the white dot area is not closed or that it is too large even if closed (S73). Also, when one round by the left method is performed in a counterclockwise direction, it is considered that the area of the white dot is not closed, but a closed area of some black dot is searched as shown in FIG. (S7
4). In these cases, the process returns to S64 and the process is repeated.
Then, by clearing all the steps S61 to S74, the specific pattern 22B can be recognized (S75).

As described above, the specific pattern 22B can be recognized by a simple algorithm.

FIG. 19 shows the specific pattern 22 shown in FIG.
4 shows an example of a processing flow for recognizing A.

First, when the specific pattern 22A is arranged in the information recording area 23 in accordance with a predetermined arrangement, the position where the specific pattern 22A should appear in the bitmap data is predicted (S41). A position P serving as a search reference is determined in the map data (S4
2). It is checked whether the dot at the reference position P is white (S43). If the dot is white, it is assumed that the dot constitutes the central closed area 44, and the process proceeds to step S4.
Proceed to 6.

On the other hand, if the dot at the reference position P is not white in S43, the next search position is determined within a certain range from the reference position P (S44), and whether or not the dot at that search position is white again Find out. All of the search within the predetermined range from the reference position P has been performed.
If the white dot corresponding to No. 4 cannot be found (S45), the process is terminated assuming that the search has failed (S50).

In step S46, a white dot connected vertically, horizontally, and diagonally to the white dot at the reference position P is recursively searched. Then, it is determined whether or not the number of connected white dots is within a certain range (S47). If the number of connected white dots exceeds a certain number, it is determined that the connected area of the white dots is not closed, or even if it is closed, the area of the central closed area 44 is too large. If the number of connected white dots is less than a certain number, it is determined that the noise is not the central closed area 44 but merely noise (S48). If the number of the connected white dots is not within the predetermined range, the process returns to S44 and the process is repeated. Then, the above steps S41 to S41
By clearing all S48, the specific pattern 22A can be recognized (S49).

As described above, the specific pattern 22A can be recognized by a simple algorithm.

Although the processing flow shown in FIGS. 16 and 19 merely checks some of the necessary conditions for forming the specific patterns 22A and 22B, the specific patterns 22A and 22B are practically used without any problem. Can be recognized. Moreover, it is efficient.

(4) Shape of cells The shape of the cells constituting the information recording area 23 has been described as a square, but the shape of the cells is not limited to a square.

As will be described later, when a reading method is used in which the recording information is read from a reading device to form bitmap data and the bitmap data is analyzed, one cell is divided into four squares on the bitmap. × 4 or 3 ×
It is necessary to have a spread of about 3 dots or more. In such a case, a square having the smallest area for the analysis of the bitmap can be realized by making the shape of the square a square. Therefore, square meshes are advantageous.

However, this is a story on bitmap data. For example, it is a scanner having a line sensor of 200 dpi in the main scanning direction and realizing 400 dpi in the sub-scanning direction by adjusting the speed of the paper feed motor. In the case of using a rectangular cell, it is more advantageous to use a rectangular cell having a length-to-width ratio of 1: 2 on the recording subject so that it can be read as a square cell on a bitmap. is there.

Further, as the shape of the mesh, a shape whose sides are not orthogonal such as a parallelogram or a polygon such as a triangle or a hexagon can be adopted. In short, the recording surface 20
Any shape can be used as long as it can be filled without gaps. For example, in FIG. 20, the information recording area 73 is formed by using a parallelogram as a grid on the recording surface 20 and the information recording area 73 is formed.
In the figure, there is shown an example in which specific patterns 72 are arranged at regular intervals. The specific pattern 72 shown in FIG.
2B is deformed in one direction to form a parallelogram. Reference numeral 71 denotes a mesh representing the original recording information.

FIG. 21 shows an example in which an information recording area 63 is formed on the recording surface 20 by using hexagons as cells, and specific patterns 62 are arranged in the information recording area 63 at regular intervals. As shown in FIG. 22, the specific pattern 62 includes a central portion 64 made of one regular hexagonal mesh with white and six regular hexagons with black surrounding the periphery thereof in a ring shape. And an annular portion 63 made of meshes. The block as a whole includes seven meshes. Reference numeral 61 denotes a mesh representing the original recording information.

(5) Mapping of Recorded Information A method of mapping recorded information in the information recording area 23 will be described with reference to the arrangement of the specific pattern 22, taking the digital information record carrier shown in FIG. 1 as an example.

In the digital information recording carrier of FIG. 1, the information recording area 23 is a virtual set of 35 × 50 = 17.
It has 50 cells. In the information recording area 23,
12 specific patterns 2 (3 horizontal × 4 vertical)
Are arranged every 15 grids horizontally and every 15 grids vertically. As described above, the specific pattern 22
, The ten specific patterns 22 belonging to the uppermost, lowermost, left and right columns are arranged along the outer periphery of the information recording area 23, and the remaining two specific patterns 22 are arranged at the outer periphery of the information recording area 23. It is arranged inside (in the vicinity of the central part) away from the center. In particular, those located at the four corners in the arrangement of the specific patterns 22 are arranged at the four corners of the information recording area 23. Each specific pattern 22 is composed of 25 (5 × 5) cells.
The number of cells used for a specific pattern out of 750 is 3
00. Therefore, the remaining 1450 squares 21
Is used to represent the original recording information, and can represent 1450 bits of information (21450 kinds of information).

FIG. 24 shows the information recording area 23 shown in FIG.
2 shows a part 23A of a 35 × 20 grid corresponding to a part (upper part) of the square. This information recording area 23A contains 6
The specific patterns 22 (3 in the horizontal direction × 2 in the vertical direction)
It is arranged every 15 squares horizontally and every 15 squares vertically. Of the 700 cells in the information recording area 23A, the number of cells used for the specific pattern 22 is 150, and the remaining 550 cells 21 are used to represent the original recording information. .., 550 (only some addresses are shown for simplicity). The address addresses are from address 1 to address 10 from the leftmost cell in the first row in contact with the specific pattern 22 at the upper left corner to address right, and further from address 11 to address 20 beyond the specific pattern 22 at the top center. I have.
Addressing is similarly performed from the second row to the fifth row, and the grid in contact with the specific pattern at the right end of the fifth row is address 100. From the sixth row to the fifteenth row, the addresses increase by one from the cell at the left end of each row toward the right. From the 16th line to the 20th line, addresses are made beyond the central specific pattern 22, as in the 1st to 5th lines. In this way, when the specific pattern 22 is arranged at the center of the row, the addressing is performed beyond the specific pattern 22. The first bit information of the recording information corresponds to the cell at the address 1, and when the value of the bit information is “1”, black is added, and when the value of the bit information is “0”, white is added to the cell. Hereinafter, similarly, the recording information is recorded, and as a result, the information recording area 2
550 bits of digital information can be mapped to 550 squares 21 of 3A.

In FIG. 24, the bit information is arranged from left to right for each row, but how to map the bit information to the cells 21 is not restricted by this example, and is freely performed. Can be.

(6) Configuration and Basic Operation of Digital Information Recording Apparatus FIG. 23 shows a schematic configuration of a digital information recording apparatus according to an embodiment of the present invention. This device includes an input device 82 as input means, an information recording device 81 as pattern generation means, and a printing device 83 as printing means.
The input device 82 includes, for example, a keyboard, a database, and the like, and can read various data. The information recording device 81 includes an input unit 84, a data conversion unit 85, an output unit 86, and a data conversion (coding) algorithm 87. The input unit 84 includes the input device 8
2 is received as input information and passed to the data converter 85. The data conversion unit 85 converts the input information received from the input unit 84 into an expression format (format) according to the present invention based on a data conversion (coding) algorithm 87, and passes the converted information to the output unit 86 as output information.

The output unit 86 outputs the output information received from the data conversion unit 85 to the printing device 83. Note that, generally, the output information passed to the printing device 83 is a bit image. The printing device 83 is configured by, for example, a dot printer, a laser printer, or the like according to a required printing accuracy.

This information recording apparatus can record various data to be recorded on the recording surface 20 of the record carrier according to the flow shown in FIG.

First, the input device 82 reads various data (S01), and reads the read data into the information recording device 81.
Is passed to the input unit 84.

In the information recording device 81, the data conversion unit 85, which has received data via the input unit 84, performs the following processing based on a data conversion (coding) algorithm 86.

First, the size of the information recording area 23 is determined according to the size of the data (S02). Information recording area 2
3 is the size of the recording information and the specific pattern 2 to be added.
It depends on the number of 2. In some cases, restrictions such as setting the width of the information recording area 23 to a fixed size, or making the shape of the information recording area 23 square, may be added. This step is not required if the size of the recording information is determined in advance.

The specific pattern 22 is arranged at a predetermined position in the information recording area 23 (S03). As this arrangement, for example, a lattice-like arrangement in which the specific pattern 22 appears at every 10th grid and every 15th grid is adopted.

[0108] Bit information of data is allocated to the cells 21 representing the original recording information in the information recording area 23 according to a predetermined mapping (S04). As this mapping, for example, the mapping described above with reference to FIG. 24 is employed.

The output unit 86 of the information recording device 81
The printing device 83 prints the recording information passed from on the recording surface 20 (S05).

As described above, according to the digital information recording apparatus, digital information can be recorded on the recording surface 20 of the record carrier.

(7) Searching for a Specific Pattern and Reading Information Using the Specific Pattern A method for decoding recorded information recorded on a digital information recording carrier as shown in FIG. 1 will be described. The recorded information is read by the reading device, and as shown in FIG.
Bitmap data consisting of black and white pixels corresponding to the recording information is obtained. In FIG. 26, the same reference numerals are used for elements corresponding to the elements on the recording surface 20 in FIG. 1 for simplicity, and a00 is used to distinguish each specific pattern 22.
To a44 are used. Decoding is performed on this bitmap data.

First, a specific pattern is searched.

First, a rectangular area corresponding to the information recording area 23 is determined from the bitmap data, and its four corners are examined. In this example, the specific patterns a00, a0
Since 4, 4, a40 and a44 are arranged, specific patterns a00, a04, a40 and a44 at the four corners are detected.

Since it is known in advance that each specific pattern 22 is the specific pattern 22B shown in FIG. 7 and is composed of 5 × 5 cells, the specific patterns a00, a04, a40, By analyzing a44, the approximate size of a cell virtually set in the information recording area 23 can be known.

Subsequently, a search is made for a specific pattern 22 arranged along the four sides of the information recording area 23. Taking the search for the specific pattern 22 along the upper side of the information recording area 23 as an example, first, the specific pattern a01 next to the specific pattern a00 at the upper left corner is searched, and then a02 and a03 are sequentially searched to the right. For example, when searching for the specific pattern a01, since it is known in advance that the specific pattern appears in the information recording area 23 at a pitch of 15 horizontal grids, the specific pattern a is located at a position advanced by 15 grids from a00 to a04.
01 is expected to appear. Therefore, the vicinity of the expected position is examined to find a shape (pattern) that matches the specific pattern 22. By repeating this operation, the specific patterns 22 along the upper side of the information recording area 23 can be sequentially found. Similarly, the specific patterns 22 along the other three sides of the information recording area 23 can be sequentially found.

Specific patterns a11-a13, a21-a near the central portion which are not adjacent to the four sides of the information recording area 23
23, a31 to a33 predict the position by utilizing the fact that the specific patterns are arranged in a grid pattern in the information recording area 23, examine the vicinity of the predicted position, and search for a shape that matches the specific pattern. be able to.

Here, the specific pattern a11 near the center portion
The following two methods can be considered as a method of searching for .about.a13, a21 to a23, and a31 to a33.

In the first search method, as shown in FIG. 27, an intersection between a straight line connecting the corresponding left and right specific patterns 22 and a straight line connecting the upper and lower corresponding specific patterns 22 is obtained, and the position of the intersection is determined. From the specific pattern 22 near the center
How to look for. That is, the specific patterns a10, a20, a30 along the left side and the specific patterns a41, a42, a43 along the right side are connected by a straight line, and the specific patterns a01, a02, a0 along the upper side.
3 and specific patterns a41, a42, a43 along the lower side
Are connected by a straight line, and the intersection b11 of these straight lines
To b13, b21 to b23, and b31 to b33.
The intersections b11 to b13, b21 to b23, b31 to b
33, specific patterns a11 to a13, a21 to a2
3, a31-a33 are expected to appear. Then, it is a method of examining the vicinity of the expected position and searching for a shape that matches the specific pattern 22. For example, when searching for a specific pattern a12, a straight line connecting a10 and a14 and a02 and a42
Is set as an expected position, and the vicinity of that position is checked to find a specific pattern a12.

The second search method is, as shown in FIG. 28, a method of predicting the position of a neighboring specific pattern 22 using three known adjacent specific patterns 22. Generally, as shown in FIG. 29, three coordinates c00, c01, c1
If 0 is known, another coordinate c11 forming a parallelogram with the three coordinates is three coordinates c00 and c0.
1 and c10 using a combination of vectors (vector c00 → c01 and vector c00 → c1).
The sum of 0 is equal to the vector c00 → c11. ). Therefore, for example, the specific patterns a00, a0
The position of the specific pattern a11 is predicted using the coordinates of a1 and a10, and the vicinity of the predicted position is examined to search for a shape that matches the specific pattern. This newly obtained specific pattern a1
The search for the specific pattern a12 is performed using the coordinates of No. 1 and the coordinates of the specific patterns a01 and a02. In this way,
Specific patterns a11 to a13, a in the vicinity of the center sequentially
21 to a23 and a31 to a33 can be searched for.

The distortion of the recording surface 20 changes continuously within the recording surface 20 as shown in FIG. Therefore, regarding the predicted position, the second position for determining the position of the neighboring specific pattern using the position information of the adjacent specific pattern 22 is used.
Is more accurate than the first search method for searching overall. However, in the second search method, once the position of the specific pattern is mistaken, the error is reflected in calculating the expected position of the next adjacent specific pattern. In contrast, the first search method does not have such a case. After all, it is not possible to say which search method is advantageous.

Next, the position (position information) of the searched specific pattern 22 is obtained.

FIG. 30 shows the specific pattern 22 shown in FIG.
B illustrates bitmap data obtained by reading B. The position of the specific pattern 22B can be indicated by the position of the center 41, and the position of the center 41 is preferably represented by the position of the center of gravity.

The position of the center of gravity of the central portion 41 in the bitmap data of FIG. 30 can be obtained by checking the positions of all the black bits constituting the central portion 41 and averaging them. When the center of gravity is determined by averaging, the more the number of samples used for averaging, the more accurate the center of gravity is determined. Since the specific pattern 22B has a symmetrical shape with respect to up, down, left and right, the position of the center of gravity of the first annular portion 42 should also match the position of the center of gravity of the center portion 41. Therefore, in the bitmap data of FIG. 30, the positions of all the black bits constituting the central portion 41 and the positions of all the white bits constituting the first annular portion 42 are respectively averaged, so that the central portion 41 is obtained. The position of the center of gravity can be obtained with high accuracy. It is also conceivable to use the information of the second annular portion 43. However, when the value of the square representing the original recording information adjacent to the outside of the second annular portion 43 is black, the second annular portion 4 is used.
Since it is difficult to distinguish the boundary between the third mesh and the area 21 representing the original recording information, it is not practical to use the information of the second annular portion 43.

Also for the specific pattern 22A shown in FIG. 6, the position of the center of gravity can be obtained by averaging the positions of all the white bits constituting the central closed area 44. However, it should be noted that the position of the center of gravity represents the middle position of the four cells constituting the central closed region 44, and does not represent any one of the cells.

Next, the value of the cell 21 representing the original recording information is obtained.

The method will be described with reference to FIG. FIG.
Reference numeral 1 schematically shows an area including four adjacent specific patterns 22 (an area including cells in M rows and N columns) in the information recording area 23. Even when the non-uniform distortion as shown in FIG. 3B occurs in the entire recording surface 20, the distortion occurs in such a small area surrounded by four adjacent specific patterns. The distortion is approximated to a nearly proportional distortion.

In FIG. 31, the position of the specific pattern 22 at the upper left (0 row and 0 column) is P ₀₀ , the position of the specific pattern 22 at the upper right (0 row and N column) is P _0N , and the lower left (M row and 0 column) ), The position of the specific pattern 22 at the lower right (Mth row, Nth column) is _PMN , and the position of the specific pattern 22 at the lower right (Mth, Nth column) is _mN , nth column in the area surrounded by these four specific patterns 22. The position of the cell of (m and n are arbitrary integers) is defined as P _mn .

The points obtained by internally dividing P ₀₀ and P _0N into n: (N−n) are denoted by P _0n , and the points obtained by internally dividing P _M0 and P _MN into n: (N−n) are denoted by P _Mn and P _Mn . _{The point at which 00} and P _M0 are internally _divided into m: (M−m) is P _m0 , and the point at which P _0N and P _MN are internally _divided into m: (M−m) is P
When _mN, the position of the meshes P _mn seeking is a straight line L1 connecting the P _0n and P _Mn, expressed as the intersection of the straight line L2 connecting the P _m0 and P _mN. The intersection P _mn between the straight line L1 and the straight line L2 is
A point where the straight line L1 is inside m: (M−m) or the straight line L2
Is divided into n: (N−n). The positions P ₀₀ , P _0N , P _M0 , P _{MN of the} four specific patterns 22
Is used to represent the position P _mn of a mesh in an area surrounded by these four specific patterns 22.

[0129]

(Equation 1)

Is obtained.

From the viewpoint of obtaining the position P _mn of a _cell representing original recording information from the positions P ₀₀ , P _0N , P _M0 , and P _{MN of the} four adjacent specific patterns 22 in a proportional manner, It is also possible to use not only a dividing point but also an external dividing point. Therefore, as shown in FIG.
Even if any specific pattern (marked with “x”) is not found among the four specific patterns 22 enclosing, the proportional division is performed using the set of the four specific patterns 22 on the right side, for example. The position P _mn of the target cell can be obtained by a method using (external division).

It is not always necessary to select adjacent ones as the four specific patterns 22. As shown in FIG. 33, when any one of the four specific patterns adjacent to each other is not found (marked with “x”), for example, four specific patterns adjacent to each other vertically and separated to the left and right A similar proportional division process is possible using the 22 sets.

Further, the method of finding the position of an arbitrary cell from the four specific patterns is not limited to the case where the information recording area is rectangular, but also the case where the information recording area is, for example, a parallelogram (FIG. 2).
0) can also be applied.

Thus, the position P _mn of the target cell can be obtained, and the value of the obtained cell can be obtained.

(8) Configuration and Basic Operation of Digital Information Decoding Device FIG. 34 shows a schematic configuration of a digital information decoding device according to an embodiment of the present invention. This device comprises a reading device 92 as reading means and an information decoding device 9 as information decoding means.
1 and an output device 93 as output means. The reading device 92 includes, for example, an image scanner, a CCD (Charge Coupled Device) camera, or the like according to the required reading accuracy.
It is possible to read the record information printed on 0.

The information decoding device 91 includes an input section 94, a data conversion section 95, an output section 96, and a data conversion (decryption) algorithm 97. The input unit 94 receives data from the reading device 92 as input information and passes it to the data conversion unit 95. Generally, the input information passed from the reading device 92 to the input unit 94 is a bit image. The data conversion section 95 decodes the input information received from the input section 94 based on a data conversion (decoding) algorithm 97 and passes the information to the output section 96 as output information. The output unit 96 outputs the output information received from the data conversion unit 95 to the output device 93. The output device 93 includes, for example, a display, a database, and the like, and displays or stores the read information.

Here, the data conversion (coding) algorithm 87 in FIG. 23 and the data conversion (decoding) algorithm 97 in FIG. Therefore, the recording information printed on the recording surface 20 by the recording device of FIG. 23 can be read by the decoding device of FIG. 34, and the same data as the original data can be obtained.

This information decoding apparatus can read information recorded on the recording surface 20 of the record carrier according to the flow shown in FIG. Here, as shown in FIG. 1, recording information in which specific patterns 22 are arranged in a grid pattern at regular intervals in information recording area 23 and specific patterns 22 are disposed at four corners of information recording area 23. Shall be decrypted.

First, the reading device 92 reads the information recorded on the recording surface 20 of the record carrier (S11), and transfers the information to the input section 94 of the information decoding device 91.

In the information decoding device 91, the data conversion unit 95, which has received the data via the input unit 94, performs the following processing based on a data conversion (decryption) algorithm 96.

First, the specific patterns 22 arranged at the four corners in the information recording area 23 are extracted (S12).

Next, the size of one cell is determined based on the information of the specific pattern 22 at the four corners (S13).

Next, the remaining specific patterns are extracted based on the predetermined arrangement information (S14). Here, the predetermined arrangement information is information on the arrangement of the specific patterns 22 such as a lattice arrangement such that the specific patterns appear every 10 grids vertically and every 15 grids horizontally.

Next, based on the information (position information) about the position of the extracted specific pattern, the position of the cell 21 representing the original recording information is determined (S15).

Next, information recorded in such a cell 21 is read out according to a predetermined mapping (S16). Here, the predetermined mapping is
For example, each mesh 21 as already described with reference to FIG.
And bit information.

The output unit 96 of the information recording device 91
The output device 93 outputs the output information passed from the
17).

As described above, according to the digital information decrypting apparatus, the digital information recorded on the recording surface 20 of the record carrier can be decrypted.

(9) Regarding Specific Patterns at Four Corners of Information Recording Area In the present invention, specific patterns 22
Are arranged, but the specific patterns 22 arranged at the four corners of the information recording area 23 have a more important meaning than the other specific patterns.

(I) In the information decoding method shown in the processing flow of FIG. 35, as shown in S12, the specific patterns 22 at the four corners of the information recording area 23 are searched prior to the other specific patterns. This is because the specific pattern 22 at the four corners is easier to find than the other specific patterns, and the area occupied by the information recording area 23 in the recording surface 20 is determined by first finding the specific pattern 22 at the four corners. There is a reason that you can do it.

That is, since the specific patterns 22 are present at the four corners of the information recording area 23, it is possible to easily recognize (so-called cut out) the area occupied by the information recording area 23 in the recording surface 20 at the time of reading. For example, in the example of FIG. 1, even if all the cells forming the information recording area 23 are white, the specific pattern 22 exists at the four corners, so that the range occupied by the information recording area 23 can be easily determined. it can. The same is true even if all the cells constituting the information recording area 23 are black. Note that it is not considered that the specific pattern is composed entirely of white cells. On the other hand, the information recording area 2
If the specific pattern 22 does not exist at the four corners of No. 3, it is not possible to distinguish white in the information recording area 23 from white outside the information recording area 23. This is because there may be a case where all cells along the outer periphery of the information recording area 23 are white.

(Ii) FIG. 37 schematically shows a method of searching for the specific patterns 22 at the four corners of the information recording area 23 from the bitmap data constituting the recording information. When searching for the specific pattern 22 at the upper left corner, scanning is performed in an oblique direction (indicated by an arrow in the figure) from the upper left corner of the bitmap data. Assuming that the outside of the information recording area 23 is constituted by white bits, the black bits appearing first in the oblique scanning are the black bits constituting the specific pattern 22 at the upper left corner. Thus, the specific pattern 22 at the upper left corner can be found. Of course, the specific pattern 22 at the upper right corner, lower left corner, and lower right corner of the information recording area 23 can be similarly found by scanning diagonally from the upper right corner, lower left corner, and lower right corner of the bitmap data.

(Iii) The technique itself for determining the range occupied by the information recording area 23 in the recording surface 20 by attaching the discrimination marks at the four corners of the information recording area 23 is conventionally known. However, conventionally, as shown in FIG. 36 (b), since the discrimination mark 29 is arranged outside the rectangular information recording area 23, the area between the discrimination marks 29, 29 is a useless area. On the other hand, as shown in FIG.
36, the area representing the original recording information can be enlarged as compared with the arrangement of FIG. 36A, and the recording surface 20 can be used without waste.

(Iv) The discrimination mark 29 shown in FIG.
An application example in which the specific pattern 22A shown in FIG. 6 or the specific pattern 22B shown in FIG. 7 is used is considered.

When a discrimination mark 29 is formed by simply adding black to one square or simply consisting of a black circle,
It is difficult to obtain information such as the size of the cells constituting the information recording area 23 due to the influence of stains during printing and ink bleeding. On the other hand, as the discrimination mark 29, FIG.
7 and the specific pattern 22B shown in FIG. 7, as described above, are less susceptible to dirt and ink bleeding during printing, and the cells forming the information recording area 23 Information such as the size can be easily obtained.

Although the specific pattern 22A shown in FIG. 6 and the specific pattern 22B shown in FIG. 7 are used as the discrimination marks, when it is not necessary to obtain information on the cells in the information recording area 23, the specific patterns 22A and 22B are used. Does not depend on the size or shape of the cells constituting the information recording area 23. For example, as shown in FIG. 38, the size of the cells forming the specific pattern 22B used as the discrimination mark may be reduced to half the size of the cells forming the information recording area 23.

(V) As shown in FIG. 39, as the specific patterns at the four corners of the information recording area 23, a pattern 22F different from the other specific patterns 22B (see FIG. 8D).
May be used. When the specific pattern 22F at the four corners of the information recording area 23 and the other specific pattern 22B are different patterns, the four corners of the information recording area 23 can be easily found by searching for the modified specific pattern 22F. However, the reading device needs to be able to recognize the two types of specific patterns 22F and 22B.

(Vi) FIG. 40 shows another example in which specific patterns at the four corners of the information recording area 23 are deformed.
In this example, as shown in FIG. 41 (the upper part of the information recording area 23 in FIG. 40 is enlarged), two sides of the second annular portion 43 of the specific pattern 22B are used as the specific patterns at the four corners. A pattern 22J formed by extending outward by two meshes is used. In this case, the area sandwiched between the extended portions 44J of the modified specific patterns 22J, 22J becomes the quiet area 29 in which neither the original recorded information nor the specific pattern 22B appears. Therefore, by detecting the silence region 29, the outer periphery of the information recording region 23 can be easily detected.

The modified specific pattern 22J can be found by using the same method as the specific pattern 22B searching method described with reference to the processing flow of FIG. FIG.
In the processing flow of (1), the central portion 41 and the first annular portion 42 of the specific pattern 22B are examined to determine
B, the deformed specific pattern 22J has the same central portion 41 and the first annular portion 42 as the specific pattern 22B.
It is because it has.

(Vii) Further, as shown in FIG. 42, the deformation specifying patterns at the four corners of the information recording area 23 may be different in the upper and lower directions. In this example, the specific patterns 22J, 22J shown in FIG. 40 are used in the upper left corner and the upper right corner as the deformation specific patterns of the four corners, and two specific patterns 22K, 22K are used in the lower left corner and the lower right corner. I have. The specific pattern 22K at the lower left corner and the lower right corner is obtained by extending the extended portion 43J (see FIG. 41) of the two sides of the specific pattern 22J toward the four corners of the information recording area 23 while maintaining its width. As described above, by making the deformation specific patterns at the four corners of the information recording area 23 different at the top and bottom,
The left and right sides of the recording surface 20 can be recognized.

As can be seen from the above, a part of the specific patterns arranged at the four corners is changed to a 90 °, 180 °, or 270 °
If the shape and the brightness are different from the remaining specific patterns arranged at the four corners so as to be asymmetric with respect to the rotation of °, the top and bottom of the recording surface 20 can be easily identified. For example, a pair of specific patterns arranged on the left side of the specific patterns arranged at the four corners may be different in shape or brightness from the other pair of specific patterns arranged on the right side, or may be arranged at the four corners. One specific pattern among the specific patterns may be different in shape and brightness from the remaining three specific patterns.

(Viii) As shown in FIG. 43, another black portion is separated from a basic pattern portion (for example, the same as the specific pattern 22B) as a deformation specific pattern at the four corners of the information recording area 23. It is also possible to employ a pattern 22L that is configured by being added in such a state. As shown in FIG. 45, the deformed specific pattern 22L has a central portion 41, a first annular portion 42, and a second annular portion 43 similarly to the specific pattern 22B, and has two sides outside the second annular portion 43. Opposing black bar-shaped portions 48 are formed of five meshes connected linearly. A white area for one mesh is provided between the two outer sides of the second annular portion 43 and each of the black bar-shaped portions 48. This deformation specifying pattern 22
L can be considered to be a specific pattern composed of 7 × 7 cells as a whole.

Further, as shown in FIG. 44, not only the specific patterns at the four corners, but also all the specific patterns arranged along the outer periphery of the information recording area 23, the black portions may be added in a separated state. good. In this example, the information recording area 2
The specific patterns 22M excluding the specific patterns 22L at the four corners of the specific patterns arranged along the outer periphery of No. 3 are outside the basic pattern portion (the same as the specific pattern 22B), and the white area for one mesh A black bar-like portion composed of five meshes connected linearly is added to the left and right sides.

As shown in FIGS. 43 and 44, when the black bar portion of the deformation specific pattern is provided so as to protrude from the information recording area 23, the specific pattern 22L at the four corners and the specific pattern M at the outer periphery can be easily found. it can.

(10) Inversion of Black and White of Specific Pattern FIG. 46 exemplifies a state in which the specific pattern 22A shown in FIG. 6 is deformed by the influence of ink bleeding, stains on the record carrier, and the like. In this example, the central closed area 4
4 is not deformed on the left and upper sides,
The right side and the lower side are black and deformed. When reading such a specific pattern 22A, the central closed area 44
If it is attempted to set the position (position information) of the entire specific pattern 22A using only the position, the position may be shifted to the upper left from the original position. Such a displacement can be corrected by using the position of the annular portion 45 of the specific pattern 22A. FIG.
In the case of the deformation shown in FIG. 7, the right and lower sides of the annular portion 45 are thicker than the left and upper sides.
This is because, contrary to the position shift of No. 4, the position shift of the annular portion 45 tends to go to the lower right.

However, in order to perform such correction, it is necessary to recognize the outer periphery (edge) of the annular portion 45. If the outside of the annular portion (black) 45 is surrounded by white cells, the edge of the annular portion 45 can be recognized. However, as shown in FIG. 47, the values of the surrounding cells 21 are all black. In such a case, the edge of the annular portion 45 cannot be recognized, and the correction cannot be performed.

Therefore, the specific pattern 22
When the contrast between the pattern 21 and the cell 21 representing the original recording information surrounding the pattern is not clear, the specific pattern 2
Means for accurately knowing the position of No. 2 is required.

As means for this, when the contrast between the specific pattern 22 and the cells surrounding the specific pattern 22 is not clear, a method of inverting and arranging the value of the specific pattern 22 is considered as follows.

That is, as shown in FIG. 48, in the information recording area 23, except for an area 25 of 4 × 4 in which a specific pattern (to be referred to as 22A) is to be arranged, first, a cell representing the original recording information. Set the value of 21. Next, cells along the area 25 (cells marked with “○” or “△” in FIG. 48)
Check the value of. Then, for example, it is determined whether or not the condition that the values of the cells marked with “○” are all black is satisfied. When this condition is satisfied, a specific pattern 22A # obtained by inverting the black and white of the specific pattern 22A is arranged in the area 25 as shown in FIG. In FIG. 49, 44
# Indicates a portion where the central closed region 44 is inverted, and 45 # indicates a portion where the annular portion 45 is inverted. On the other hand, when the condition that all the values of the cells marked with “」 ”in FIG. 48 are not black is not satisfied, the normal specific pattern 22A is arranged in the area 25.

In this case, the specific pattern 22A
And the contrast between the cell 21 and the cells 21 that represent the original recording information surrounding the cell can be clarified.

The specific patterns 22A and 22A # are searched from the information recording area 23 in which the specific patterns 22A and 22A # are arranged as follows. Note that a new algorithm is not required to search for the inverted specific pattern 22A #, and an algorithm for searching for the normal specific pattern 22A is shared.

The search processing will be described with reference to the processing flow shown in FIG.

First, a search is performed on the assumption that a normal non-inverted specific pattern 22A is used as the specific pattern 22. The search process is started from S41, and if the normal specific pattern 22A is found, the search is successful (S49).
Then, the processing ends. Normal specific pattern 2
If 2A is not found, the search fails (S50). However, the process does not end in S50, returns to S42, and continues to search for the inverted specific pattern 22A #. At this time, for all the processing from S42 to S49,
The processing is performed by changing the parameters “black → white” and “white → black”. That is, the first processing (normal specific pattern 22
In the process (search for A), a pattern in which a white region is surrounded by a black region is searched, whereas in the second time (process for searching the inverted specific pattern 22A #), the black region is surrounded by a white region. Look for patterns that look like If the inverted specific pattern 22A # is found, the process is terminated assuming that the search was successful (S50). On the other hand, if neither the normal specific pattern 22A nor the inverted specific pattern 22A # is found, the process ends assuming that the search has failed (S50). By setting a specific pattern search algorithm using white and black as parameters,
Specific pattern 22 inverted from normal specific pattern 22A
A # can be searched by the same algorithm.

As described above, by using the normal specific pattern 22A and the inverted specific pattern 22A # properly, at least one of the upper, lower, left, and right sides of the specific pattern 22A, the boundary line (edge) between the black and white cells is formed. Can be detected. Using the edge information representing this boundary line, the width of at least one of the upper, lower, left, and right sides of the annular portion 45 of the specific pattern 22A can be detected. FIG.
In the case of the deformation in which the right side and the lower side are thicker than the left side and the upper side of the annular portion 45 as shown in the above, contrary to the positional shift of the central closed region 44, the positional shift of the annular portion 45 is in the lower right. Since there is a tendency to move, it is possible to detect or correct an error in the position information of the specific pattern 22A.

The reason why the search algorithm for the specific pattern 22A and the pattern 22A # obtained by inverting the specific pattern 22A can be shared simply by changing the parameters of “black → white” and “white → black” is as follows. This is because the configuration of “surrounded by a part” does not change by the black-and-white inversion.

As can be seen from this, the method of inverting black and white can be applied to the specific pattern 22B shown in FIG. 7 so as to have a contrast with the surrounding cells representing the original recording information. Specific pattern 22
In B, the configuration that “the first annular portion is surrounded by the second annular portion” does not change due to the black-and-white inversion.

[0176]

As is apparent from the above description, in the digital information recording carrier according to the first aspect, since the specific pattern is arranged inside the information recording area, even if the vicinity of the center of the information recording area is distorted, the specific information is recorded. Based on the position of the pattern, the position of the mesh near the center of the information recording area can be obtained with high accuracy. Therefore, even if the area of the information recording area is increased, it is possible to prevent a reading error from occurring near the center of the information recording area. Further, in the peripheral portion of the information recording area, the occurrence of a reading error can be prevented by providing clocking information or providing the specific pattern as in the related art. Therefore, the storage capacity can be increased by increasing the area of the information recording area. In addition, the specific pattern includes a central closed area composed of four meshes with light as the mark, and a continuous area surrounding the central closed area, and twelve squares with darkness as the mark. It consists of an annular part consisting of eyes. Therefore, the specific pattern can be easily found in the information recording area. In addition, the number of cells constituting the specific pattern can be relatively reduced. Further, when the same or similar pattern appears in the vicinity as the original recording information, the specific pattern is unlikely to overlap the pattern. Further, the specific pattern is less susceptible to effects such as stains during printing and ink bleeding. Also, a specific pattern can be found with a simple algorithm.

According to the digital information recording carrier of the present invention, since the specific pattern is arranged in the information recording area, even if the vicinity of the center of the information recording area is distorted, the information recording is performed based on the position of the specific pattern. The position of the mesh in the vicinity of the center of the area can be obtained with high accuracy. Therefore,
Even if the area of the information recording area is increased, it is possible to prevent a reading error from occurring near the center of the information recording area. Further, in the peripheral portion of the information recording area, the occurrence of a reading error can be prevented by providing clocking information or providing the specific pattern as in the related art. Therefore, the storage capacity can be increased by increasing the area of the information recording area. In addition, the specific pattern includes a central portion formed of a single cell shaded as the mark,
A first annular portion consisting of eight meshes marked with the light as the mark is continuously surrounded around the center portion, and the periphery of the first annular portion is continuously surrounded and the mark is darkened. And a second annular portion comprising 16 meshes. Therefore, similarly to the first aspect, the specific pattern can be easily found in the information recording area. Also,
The number of cells constituting the specific pattern can be relatively reduced. Further, when the same or similar pattern appears in the vicinity as the original recording information, the specific pattern is unlikely to overlap the pattern. Further, the specific pattern is less susceptible to effects such as stains during printing and ink bleeding. In addition, a simple algorithm can look at a specific pattern.

In the digital information recording carrier according to the third aspect, since the plurality of specific patterns are dispersedly arranged over the entire area of the information recording area, the position of an arbitrary cell can be accurately determined over the entire area of the information recording area. Can be found well. Therefore, the storage capacity can be increased by increasing the area of the information recording area.

According to the digital information recording carrier of the present invention, the specific pattern is arranged at a higher density around the information recording area than inside the information recording area. It is possible to improve the reading accuracy of the peripheral portion where distortion is likely to occur, and it is possible to prevent a reading error from occurring.

In the digital information recording carrier according to the fifth aspect, since the specific pattern is arranged at a higher density inside the information recording area than at a peripheral portion of the information recording area, the specific pattern is formed in the information recording area. The reading accuracy near the center can be improved, and the occurrence of a reading error can be prevented.

In the digital information recording carrier of the present invention, the information recording area is a rectangular area, and the specific pattern is arranged at a corner of the information recording area. Thus, the range occupied by the information recording area on the recording surface can be easily determined.

According to the digital information recording carrier of the present invention, the specific pattern arranged in the corner has a different shape and lightness / darkness from other specific patterns arranged in the information recording area. By searching for a specific pattern, the range occupied by the information recording area on the recording surface can be easily determined.

In the digital information recording carrier according to the present invention, a part of the specific patterns arranged at the corners may be such that the set of specific patterns at the corners is 90 ° or 180 ° within the recording surface.
Alternatively, since the shape and brightness of the remaining specific patterns arranged in the corners are different from each other so as to be asymmetric with respect to the rotation of 270 °, it is possible to easily recognize the top, bottom, left and right of the information recording area. it can.

[0184] In the digital information recording carrier according to the ninth aspect, in the information recording area, the specific pattern having a constant brightness as the mark and the specific pattern may be formed so as to have a contrast with the surrounding cells representing the original recording information. Since the specific pattern obtained by inverting the light and dark is arranged, it is possible to easily recognize the boundary between the specific pattern and the surrounding cells representing the original recording information. As a result, each specific pattern can be easily searched.

According to the digital information recording method of the tenth aspect, the digital information recording carrier of the first to ninth aspects can be easily prepared.

According to the digital information recording method of the eleventh aspect, it is possible to easily recognize the boundary between the specific pattern and the surrounding mesh representing the original recording information on the recording surface of the digital information recording carrier. As a result, each specific pattern can be easily searched.

According to the digital information decoding method of the twelfth aspect, the digital information recorded on the recording surface of the digital information recording carrier of the first to ninth aspects can be easily reproduced.

According to the digital information decoding method of claim 13, when searching for the specific pattern according to claim 1 in the information recording area, the specific pattern can be easily and easily recognized.

According to the digital information decoding method of claim 14, when searching for the specific pattern according to claim 2 in the information recording area, the specific pattern can be easily and easily recognized.

According to the digital information recording device of the present invention, the digital information recording carrier of the present invention can be easily prepared.

According to the digital information decrypting device of the present invention, digital information recorded on the digital information recording carrier of the present invention can be easily decrypted.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a digital information recording carrier according to one embodiment of the present invention.

FIG. 2 is a diagram schematically showing the digital information record carrier of FIG. 1;

FIG. 3 is a diagram showing a state where the recording surface of the digital information recording carrier is distorted in comparison with a state where the recording surface of the conventional digital information recording carrier is distorted.

FIG. 4 is a diagram showing an example in which specific patterns are arranged at high density in a peripheral portion of an information recording area.

FIG. 5 is a diagram showing an example in which specific patterns are arranged at a high density at the center of an information recording area.

FIG. 6 is a diagram showing a preferred example of a specific pattern.

FIG. 7 is a diagram showing another preferred example of the specific pattern.

FIG. 8 is a diagram showing various examples of a specific pattern.

FIG. 9 shows a checkerboard specific pattern shown in FIG.
It is a figure showing the state where it overlapped with the same pattern which appeared near it.

FIG. 10 is a diagram showing a state where the specific pattern of FIG. 6 overlaps with the same pattern appearing in the vicinity thereof.

FIG. 11 is a diagram showing a state where the specific pattern of FIG. 7 overlaps with the same pattern appearing in the vicinity thereof.

FIG. 12 is a diagram showing an aspect of the specific pattern shown in FIG. 8 (g) when a blur occurs such that each side of a black cell is spread by a factor of 1.4.

FIG. 13 is a diagram showing an aspect of the specific pattern of FIG. 6 when a blur occurs such that each side of a black square is spread by 1.4 times.

FIG. 14 is a diagram showing an aspect of the specific pattern of FIG. 7 when a blur occurs such that each side of a black square is spread by 1.4 times.

FIG. 15 is a diagram showing an aspect when one of the white cells constituting the central closed area is changed to a black cell in the specific pattern of FIG. 6;

FIG. 16 is a diagram illustrating an example of a processing flow for recognizing the specific pattern in FIG. 7;

When recognizing the specific pattern in FIG. 7, the boundary between the first annular portion and the second annular portion is circled by the left method,
It is a figure showing typically how to check the 2nd annular part.

FIG. 18 is a diagram schematically illustrating a state in which a closed black dot area is circled by the left method in FIG. 17;

FIG. 19 is a diagram illustrating an example of a processing flow for recognizing the specific pattern in FIG. 6;

FIG. 20 is a diagram showing an example in which a specific pattern is arranged in an information recording area having a parallelogram as a mesh;

FIG. 21 is a diagram showing an example in which a specific pattern is arranged in an information recording area having hexagons as meshes.

FIG. 22 is a diagram showing a specific pattern arranged in the information recording area of FIG. 21;

FIG. 23 is a diagram showing a block configuration of a digital information recording device according to an embodiment of the present invention.

FIG. 24 is a diagram illustrating a mapping method for associating bit information to be originally recorded with cells in an area other than an area where a specific pattern is to be arranged in an information recording area.

FIG. 25 is a diagram schematically showing a processing flow for implementing a digital information recording method according to an embodiment of the present invention;

FIG. 26 is a diagram showing bitmap data obtained by reading the digital information record carrier of one embodiment by a reading device.

FIG. 27 is a diagram illustrating a first search method for searching for a specific pattern near the center of the information recording area based on the position of the specific pattern along the outer periphery of the information recording area.

FIG. 28 is a diagram illustrating a second search method for searching for a specific pattern near the center of the information recording area based on the position of the specific pattern along the outer periphery of the information recording area.

FIG. 29 is a diagram illustrating a method of obtaining another coordinate constituting a parallelogram by using vector synthesis using three known coordinates.

30 is a diagram showing bitmap data obtained by reading the specific pattern of FIG. 7 by a reading device.

FIG. 31 is a diagram illustrating a method of calculating the position of an arbitrary cell in the information recording area based on the positions of four specific patterns.

FIG. 32 is a diagram illustrating a modification of the method of calculating the position of an arbitrary cell in the information recording area based on the positions of four specific patterns.

FIG. 33 is a diagram illustrating a further modification of the method of calculating the position of an arbitrary cell in the information recording area based on the positions of four specific patterns.

FIG. 34 is a diagram showing a block configuration of a digital information decoding device according to an embodiment of the present invention.

FIG. 35 is a diagram schematically showing a processing flow for implementing a digital information decoding method according to an embodiment of the present invention;

FIG. 36 is a diagram showing a comparison between an example in which specific patterns are arranged at four corners of an information recording area and an example in which the specific patterns are arranged outside the information recording area;

FIG. 37 is a diagram illustrating a method of searching for a specific pattern at four corners of an information recording area.

FIG. 38 is a diagram showing an example in which a specific pattern composed of meshes having dimensions different from those in the information recording area is arranged at the upper left corner of the information recording area.

FIG. 39 is a diagram showing an example in which specific patterns at four corners of an information recording area are different from other specific patterns.

FIG. 40 is a diagram showing another example in which specific patterns at four corners of an information recording area are different from other specific patterns.

FIG. 41 is an enlarged view showing an upper portion of the information recording area of FIG. 40;

FIG. 42 shows a specific pattern at four corners of an information recording area;
It is a figure which shows the example which made a pair of upper specific patterns different from a pair of lower specific patterns.

FIG. 43 is a diagram showing still another example in which specific patterns at four corners of an information recording area are different from other specific patterns.

FIG. 44 is a diagram showing an example in which the specific pattern at a position along the outer periphery of the information recording area is different from the specific pattern inside the information recording area in the example of FIG. 43;

FIG. 45 is an enlarged view showing a specific pattern arranged at the upper left corner of the information recording area in FIGS. 43 and 44.

FIG. 46 is a diagram showing an example in which the right side and the lower side of the central closed area of the specific pattern in FIG. 6 are blackened;

FIG. 47 is a diagram showing a state in which all surrounding squares surrounding the specific pattern in FIG. 6 are blackened;

FIG. 48 is a diagram illustrating conditions for determining whether or not to arrange a specific pattern by inverting black and white.

FIG. 49 is a diagram showing a mode when the specific pattern of FIG. 6 is arranged with black and white inverted.

FIG. 50 is a diagram showing an embodiment of a conventional digital information recording carrier.

[Explanation of symbols]

20 recording surface 21 area where original information is to be recorded 22, 22A, 22B, 22C, ..., 22M, 62, 7
2 Specific pattern 23 Information recording area 41 Central part 42 First annular part 43 Second annular part 44 Central closed area 45 Annular part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiro Esashi 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Hiroaki Niwamoto 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Norimasa Yamaguchi, the inventor No. 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture Within Sharp Co., Ltd. (72) Tsukasa Jinnomon 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka In the company

Claims (16)

[Claims] An information recording area provided in a planar recording surface virtually sets a matrix of matrixes corresponding to bits, and optically sets a matrix corresponding to digital information to be recorded in each of the above-mentioned squares. A digital information recording carrier in which a recognizable mark is provided and the digital information to be recorded is recorded as a two-dimensional pattern, wherein the mark is formed in a plurality of cells connected to a specific shape in the information recording area. Are arranged in a predetermined pattern, the meshes have the same shape, and the specific pattern is marked 4 as the mark.
A central closed area composed of a plurality of meshes and a surrounding area surrounding the central closed area in a row,
A digital information recording carrier comprising: an annular portion comprising two meshes. 2. A method according to claim 1, further comprising: setting virtually a matrix of matrixes corresponding to the bits in an information recording area provided in the planar recording surface; A digital information recording carrier in which a recognizable mark is provided and the digital information to be recorded is recorded as a two-dimensional pattern, wherein the mark is formed in a plurality of cells connected to a specific shape in the information recording area. Are arranged in a predetermined pattern, and each of the meshes has the same shape, and the specific pattern has a dark mark 1 as the mark.
A central portion made up of individual meshes and a periphery of the central portion are continuously connected to each other, and a first annular portion composed of eight meshes marked with the mark as the mark is connected to the periphery of the first annular portion. A digital information recording carrier, comprising a second annular portion formed of 16 meshes which are surrounded and shaded as the mark. 3. The digital information recording carrier according to claim 1, wherein a plurality of the specific patterns are dispersedly arranged over the entire area of the information recording area. 4. The digital information recording carrier according to claim 1, wherein the specific pattern has a higher density in a peripheral portion of the information recording area than in the information recording area. A digital information record carrier, which is arranged. 5. The digital information recording carrier according to claim 1, wherein the specific pattern has a higher density inside the information recording area than at a peripheral part of the information recording area. A digital information recording carrier, which is arranged. 6. The digital information recording carrier according to claim 1, wherein the information recording area is a rectangular area, and the specific pattern is arranged at a corner of the information recording area. A digital information record carrier. 7. The digital information recording carrier according to claim 6, wherein the specific pattern arranged in the corner has a different shape and brightness from other specific patterns arranged in the information recording area. A digital information record carrier characterized by the following. 8. The digital information record carrier according to claim 6, wherein a part of the specific pattern disposed at the corner is such that a set of the specific pattern at the corner is 90 ° in the plane of the recording surface. , 180 ° or 270 °, so that the shape and the brightness of the remaining specific pattern are different from each other so as to be asymmetric with respect to the rotation of 180 ° or 270 °. 9. The digital information recording carrier according to claim 1, wherein the information recording area includes a specific pattern having a constant brightness as the mark, and a surrounding pattern representing the original recording information. A digital information recording carrier, wherein a specific pattern obtained by inverting the brightness of the specific pattern is arranged so as to form a contrast with the mesh. 10. A matrix in the form of a matrix corresponding to bits is virtually set in an information recording area provided in a planar recording surface, and optically corresponding to digital information to be recorded in each of the above-mentioned cells. A digital information recording method for providing a recognizable mark and recording the digital information to be recorded as a two-dimensional pattern, comprising: Arranging a specific pattern in which the mark is provided in a predetermined pattern on a square, and recording digital information to be originally recorded in an area of the information recording area other than an area where the specific pattern is to be arranged. A digital information recording method characterized by the above-mentioned. 11. The digital information recording method according to claim 10, wherein the digital information to be originally recorded is recorded in an area of the information recording area other than the area where the specific pattern is to be arranged, and then the specific pattern is recorded. Is compared with the lightness and darkness of a mesh around the area where the is to be arranged and the lightness and darkness of a portion of the specific pattern adjacent to the surrounding meshes. When the compared lightness and darkness match, the specific pattern is arranged. A digital information recording method, wherein a specific pattern obtained by inverting the brightness of the specific pattern is arranged in a region to be replaced, instead of the specific pattern. 12. A digital information decryption method for decrypting information recorded on a digital information recording carrier according to claim 1, wherein the specific pattern is searched for in the information recording area. Of the specific pattern searched, and two specific rows and two specific
Based on the positions of the four specific patterns located in the column, the position of an arbitrary cell where the original information is recorded is calculated by proportional distribution, and the bit information represented by the cell at the calculated position is read.
A digital information decoding method, characterized by reproducing digital information recorded on the recording surface based on the bit information. 13. The digital information decoding method according to claim 12, wherein, when searching for the specific pattern according to claim 1 in the information recording area, a reference position of a reference position where a central closed area of the specific pattern should exist. Examining light and darkness, and determining that the reference position is included in the central closed region when the lightness and darkness of the reference position are bright; and for a region where light including the reference position is connected, Checking whether the area, width, and height are each within a predetermined range, and confirming that the area is the central closed area, thereby recognizing the specific pattern. Digital information decryption method. 14. The digital information decoding method according to claim 12, wherein, when searching for the specific pattern according to claim 2 in the information recording area, a reference position where the center of the specific pattern should be arranged. Examining the brightness of the reference position, when the reference position is dark, determining that the reference position is included in the center portion; and for a region where the darkness including the reference position is connected, the area of this region, Checking whether the width and the height are each within a certain range, and confirming that this area is the center part; and Appearing and making a round along the boundary between the bright area and the dark area, confirming that the bright area is the first annular portion, thereby recognizing the specific pattern. Digital information decoding method characterized by the the like. 15. A cell in a matrix corresponding to bits is virtually set in an information recording area provided in a plane recording surface, and optically corresponding to digital information to be recorded in each cell. What is claimed is: 1. A digital information recording apparatus for recording a digital information to be recorded as a two-dimensional pattern by providing a recognizable mark, comprising: an input unit for inputting the digital information to be recorded; A specific pattern in which the mark is provided in a predetermined pattern on a plurality of cells connected to a specific shape is arranged inside the space separated from the outer periphery, and an area of the information recording area where the specific pattern is to be arranged. Place digital information that should be recorded in areas other than
A digital information recording apparatus, comprising: pattern generation means for generating a two-dimensional pattern to be printed on the recording surface; and printing means for printing the two-dimensional pattern generated by the pattern generation means on a recording surface. 16. A digital information decoding device for reading and decoding digital information from the digital information recording carrier according to claim 1, wherein the device reads a two-dimensional pattern recorded on the recording surface. Reading means for outputting information representing the two-dimensional pattern; searching for the specific pattern in the two-dimensional pattern represented by the output information of the reading means to determine its position; Based on the positions of the four specific patterns located in two rows and two columns, the position of an arbitrary cell in which the original information is recorded is calculated by proportional distribution,
Read the bit information represented by the mesh at the calculated position,
A digital information decoding device comprising: information decoding means for reproducing digital information recorded on the recording surface based on the bit information; and output means for outputting digital information reproduced by the information decoding means.