JP5715543B2 - Two-dimensional symbol and printing method thereof - Google Patents

Description

  The present invention relates to a two-dimensional symbol capable of recording information represented by a binary code and optically reading the recorded information and a printing method thereof.

  Two-dimensional symbols are widely used because they can record information represented by binary codes of about 2,000 bytes and have a recording capacity that is several tens to about one hundred times that of barcodes. For example, as shown in FIG. 10A, the two-dimensional symbol is configured by arbitrarily arranging a plurality of square bright cells 10 and dark cells 20 vertically and horizontally. The bright cell 10 is usually composed of a plurality of uncolored bright dots 100, and the dark cell 20 is composed of a plurality of colored dark dots 200. The two-dimensional symbol 50A thus configured is information in which binary code is recorded in an array pattern of bright cells 10 and dark cells 20, and the brightness of the bright cells 10 and dark cells 20 is optically measured by a scanner or the like. The information is read by judgment. For this reason, the two-dimensional symbol is required not to be erroneously recognized but to have high reading accuracy.

  Since a two-dimensional symbol normally prints only dark cells on a print medium, the size after printing needs to be the same for dark cells and light cells. However, in flexographic printing and gravure printing, there is a problem that dark cells tend to thicken due to the plate pressure for transfer when ink is applied to a printing medium. In order to solve this problem, a technique such as BWR (Bar Width Reduction), which reduces the width of the dark cell plate by taking into account the thickening due to the plate pressure, has been established.

  On the other hand, when printing a two-dimensional symbol by the ink jet method, there is an advantage that there is no step of transferring ink attached to a plate, and printing on a printing medium is possible without contact. There is no need to consider the thickness. However, before ink is fixed, adjacent inks become familiar with each other, and there is a problem that the ink easily spreads on the print medium. In particular, when printing on a printing medium such as plastic or metal where ink is difficult to penetrate by the inkjet method, such a problem is likely to occur, and the ink spreads to adjacent bright cells, resulting in a decrease in reading accuracy. It was.

  As means for solving such a problem, Patent Document 1 proposes a technique for printing a two-dimensional symbol with a small amount of ink. Further, Patent Document 2 proposes a technique for making some or all of the dots constituting the outermost periphery of the dark cell smaller than dots other than the outermost periphery. Japanese Patent Application Laid-Open No. 2004-228561 is a technology that sets an offset value that allows for the amount of change in the size of a dark cell that constitutes a two-dimensional symbol on a print medium, and makes only the outermost peripheral dot of the dark cell a bright dot. Has been proposed. Patent Document 4 proposes a technique of alternately arranging bright dots and dark dots in the circumferential direction with respect to the dots constituting the outermost periphery of the dark cell.

  Among these, in the techniques described in Patent Documents 1 and 2, the amount of ink ejected can be changed by increasing or decreasing the capacity of the ink chamber communicating with the ink nozzle, thereby preventing ink bleeding.

JP 2000-103042 A JP 2003-237059 A JP 10-49610 A JP 2004-102350 A

  However, in the techniques described in Patent Documents 1 and 2, since the ink discharge amount has to be controlled for each dot, there is a problem in that the control and structure become complicated and fine maintenance is required.

  In the techniques described in Patent Documents 3 and 4, ink bleeding can be prevented by reducing the number of outermost dark dots from half to zero. However, with this technique, the number of dark dots on the outermost periphery is reduced from half to zero, and the reflectivity of dark cells may increase, especially when the number of dots per cell is small. As a result, the contrast of the dark cell is lowered, and the dark cell may be erroneously recognized as a bright cell, which may cause a reduction in information reading accuracy.

  In the course of conducting research to solve the above-described conventional problems, the present inventor has found the largest cause of a decrease in reading accuracy, and solved the above-described conventional problems by solving the cause. FIG. 10A is an enlarged view of a two-dimensional symbol having an ideal shape, and FIG. 10B is an enlarged view of a two-dimensional symbol actually printed by the ink jet method. The two-dimensional symbol is composed of a bright cell 10 and a dark cell 20, and the contacts 30, 30 'indicate points where the rectangular dark cells 20 are in contact with each other in the diagonal direction. As shown in FIG. 10B, in the bright cell 10 adjacent to the dark cell 20 on at least two consecutive sides, the ink in the dark cell 20 is at the contact 30 ′ where the rectangular dark cells 20 are in contact with each other in the diagonal direction. The area of the bright cell 10 was reduced by spreading to the top of the bright cell 10 and spreading. That is, it has been found that such a phenomenon is the main cause of the decrease in the reading accuracy of the two-dimensional symbol, and has found that this phenomenon may cause a decrease in the reading accuracy of the two-dimensional symbol information.

  The present invention has been made in order to solve the main cause of the conventional problem found by the present inventor, and an object of the present invention is to perform a two-dimensional symbol having high reading accuracy without performing complicated processing and the same. It is to provide a printing method.

A two-dimensional symbol according to the present invention for solving the above-described problem is configured by a rectangular and a plurality of bright cells and a plurality of dark cells and a plurality of dark cells, each of which is composed of a plurality of dots . Among the dark cells adjacent to at least two consecutive sides of the bright cell, only one or two or more dots at the top of the dark cell that are in contact with each other in the diagonal direction are formed as bright dots, and 1 of the top of the dark cell. Alternatively, the dots of the dark cells other than the dots formed in two or more bright dots are formed as dark dots, and the dark cells other than the dark cells adjacent to at least two consecutive sides of the bright cells among the plurality of dark cells The cell is characterized in that all dots constituting the dark cell are dark cells .

  According to the present invention, the dark cell adjacent to at least two continuous sides of the bright cell has one or more dots at the top of the dark cell that are in contact with each other in the diagonal direction. The ink does not spread and blot at the contact point where they touch each other. As a result, the conventional phenomenon that the ink spreads on the top of the bright cell and reduces the area of the bright cell does not occur, so that it is possible to prevent the reading accuracy of the two-dimensional symbol information from being lowered. According to the present invention, it is not necessary to apply a complicated process or apparatus as in the prior art, and a two-dimensional symbol with high reading accuracy can be provided.

  In the two-dimensional symbol according to the present invention, when one or more bright dots at the top of the dark cell draw a circle or ellipse inscribed on the four sides of the square or rectangular dark cell, the circle or ellipse Among the crossing dots, a dot whose area outside the circle or ellipse of the dot is more than half of the area of the dot and a dot outside the dot, or 2 inscribed in the three sides of the rectangular dark cell When two circles are drawn, among the dots that the circle crosses within the area surrounded by two continuous sides of the circle and the dark cell, the area outside the circle of the dot is the area of the dot A dot that is more than half and a dot outside the dot.

  According to the present invention, when one or more bright dots at the top of a dark cell draw a circle or ellipse inscribed on the four sides of a square or rectangular dark cell, among the dots that the circle or ellipse crosses, When you draw a dot that has an area outside the dot circle or ellipse that is more than half the area of the dot and a dot that is outside the dot, or two circles that touch the three sides of the rectangular dark cell In the area surrounded by two continuous sides of the circle and the dark cell, among the dots that the circle crosses, the dot that has an area outside the circle of the dot that is more than half the area of the dot and the dot Since the dots are on the outside, for example, when dark cells are formed with a large number of dots, the inks do not become familiar and spread at the contact points where the dark cells contact each other in the diagonal direction.

  In the two-dimensional symbol according to the present invention, among the dark cells, the dark cells in one row or one column are formed by only dark dots, or all the dark cells are on one side of the four tops. One or two or more dots at the two tops on both sides are formed as bright dots, and other than the bright dots are formed as dark dots.

  According to the present invention, the dark cells in one row or one column among the dark cells are formed by only the dark dots, or all the dark cells are formed on the two tops on both sides of one side of the four tops. Since one or more dots are formed as bright dots and other than the bright dots are formed as dark dots, only one of the dots at the top of the dark cell adjacent in the diagonal direction is formed as a bright dot. . For this reason, the dark dots at the tops of the dark cells do not contact each other in the diagonal direction, so that there is no possibility that the inks become familiar and spread. Moreover, since it can suppress that the reflectance of a dark cell becomes high, the fall of the contrast of a dark cell can be suppressed. As a result, a two-dimensional symbol with high information reading accuracy can be provided.

In order to solve the above problems, a two-dimensional symbol printing method according to the present invention is a two-dimensional symbol printing method in which a plurality of rectangular and plurality of bright cells and a plurality of rectangular and dark cells are arranged vertically and horizontally. Of the plurality of dark cells, only one or two or more dots at the top of the dark cells that are in contact with the dark cells adjacent to at least two continuous sides of the bright cells in the diagonal direction are light dots. The dots of the dark cell other than the dots formed on the one or more bright dots at the top of the dark cell are dark dots, and among the plurality of dark cells, at least two continuous sides of the bright cell. dark cells other than the dark cells adjacent to is characterized in that all of the dots constituting the dark cell is printed so that such a dark cell.

  In the two-dimensional symbol printing method according to the present invention, when one or more bright dots at the top of the dark cell draw a circle or an ellipse inscribed on the four sides of the dark cell that is square or rectangular, Or, among the dots traversed by the ellipse, the dot outside the circle or ellipse of the dot is half or more of the area of the dot and the dot outside the dot, or on the three sides of the rectangular dark cell When two inscribed circles are drawn, the area outside the circle of the dots among the dots crossed by the circle in the area surrounded by the two continuous sides of the circle and the dark cell is the dot. A dot that is more than half the area of the dot and a dot outside the dot.

  According to the two-dimensional symbol and the printing method thereof according to the present invention, the ink does not spread and spread at the contact point where the dark cells contact each other in the diagonal direction, so that the ink spreads on the top of the bright cell and the area of the bright cell is reduced. The conventional phenomenon of reducing the size does not occur. As a result, it is possible to prevent a decrease in reading accuracy of 2D symbol information, and it is not necessary to apply complicated processing and equipment as in the prior art, and a 2D symbol with high reading accuracy is provided. it can.

It is a schematic diagram which shows an example of the two-dimensional symbol which concerns on this invention. It is a schematic diagram which shows another example of the two-dimensional symbol which concerns on this invention. It is a schematic diagram which shows another example of the two-dimensional symbol which concerns on this invention. It is a schematic diagram which shows another example of the two-dimensional symbol which concerns on this invention. It is a schematic diagram which shows another example of the two-dimensional symbol which concerns on this invention. (A) is an enlarged view showing an example of a two-dimensional symbol according to the present invention, and (B) is an enlarged view showing another example of a two-dimensional symbol according to the present invention. (A) is a schematic diagram showing an application example of the two-dimensional symbol according to the present invention, (B) is a schematic diagram showing another application example of the two-dimensional symbol according to the present invention, and (C) is a schematic diagram showing the present invention. It is a schematic diagram which shows the other application example of the two-dimensional symbol which concerns on. It is a schematic diagram which shows the example of a two-dimensional symbol. It is an enlarged view explaining the basic composition of a two-dimensional symbol. (A) is an enlarged view of a two-dimensional symbol having an ideal shape, and (B) is an enlarged view of a two-dimensional symbol actually printed by the ink jet method.

  Hereinafter, a two-dimensional symbol and a printing method thereof according to the present invention will be described in detail with reference to the drawings. The present invention can be modified in various ways as long as it has the technical features, and is not limited to the embodiments specifically shown below.

[Two-dimensional symbol]
(Basic configuration)
The two-dimensional symbol 1 (1A, 1B) according to the present invention can record information represented by a binary code, and can optically read the recorded information. As shown, a rectangular bright cell 10 formed by a plurality of bright dots 100 and a rectangular dark cell 20 formed by a plurality of dark dots 200 are arranged vertically and horizontally. Further, the dark cell 20 adjacent to at least two continuous sides of the bright cell 10 is characterized in that one or more dots at the top of the dark cell 20 in contact with the diagonal direction are formed by the bright dots 100.

  The bright cell 10 is formed by arranging a plurality of uncolored bright dots 100 vertically and horizontally. The shape of the bright cell 10 is a rectangle, and the size thereof is n dots × m dots in rows × columns (n and m are integers of 3 or more). In the present specification, “rectangular” means a square and a rectangle.

  The dark cell 20 is formed by arranging a plurality of colored dark dots 200 vertically and horizontally. The dark dot 200 is a colored dot, and the uncolored portion becomes the bright dot 100 as a result. Therefore, the portion where the dark cell 20 is not formed becomes the bright cell 10. The shape and size of the dark cell 20 are the same as those of the bright cell 10. In FIG. 1 to FIG. 7, the dark cell 20 is shown in gray for easy understanding, but normally the dark cell 20 is shown in black as shown in FIG.

  The types of the two-dimensional symbol 1 include a stack type and a matrix type. Among them, the stack type includes “PDF417” in FIG. 8A, and the matrix type is as shown in FIG. 8B. “QR code” (registered trademark of DENSO WAVE INCORPORATED) having quadrilateral cut-out symbols at the three corners of the two-dimensional symbol 1 or L on two consecutive sides of the two-dimensional symbol 1 as shown in FIG. There is “DataMatrix” or the like having a cut-out symbol of a letter-shaped line. The cut-out symbol represents the directionality of the two-dimensional symbol 1. The present invention is not limited to such a format, and can be applied to any two-dimensional symbol 1.

  The two-dimensional symbol 1 in FIG. 9 is configured by arranging four cells vertically and horizontally, and centering on a contact point 30 where the tops of the four cells (referred to as “corners”) contact. From the cell in the upper right (first quadrant) to the cell in the lower right (fourth quadrant), the light cell 10, the dark cell 20, the light cell 10, and the dark cell 20 are arranged in this order. The dark cell 20 has four apexes C2, C3, and C4 clockwise from the top left top C1. Similarly, the bright cell 10 has four apexes C′1, C′2, C′3, and C′4 clockwise from the top left.

  In FIG. 9, the dark cell 20 adjacent to at least two consecutive sides of the bright cell 10 is, for example, one side connecting the tops C′1 and C′4 of the bright cell 10 on the upper right, The two dark cells 20 are adjacent to two consecutive sides composed of one side connecting C′4 and C′3. The dark cell 20 touching the diagonal direction means that the dark cells 20 touch each other in the diagonal direction of the dark cell 20 like the dark cell 20, and more specifically, the top of the dark cell 20 at the upper left. C3 and the top C1 of the lower right dark cell 20 are in contact with each other in the diagonal direction of the dark cell 20 at the contact point 30.

  The two-dimensional symbol 1 includes the first embodiment (two-dimensional symbol 1A shown in FIG. 1) in which one or more dots at the top of some dark cells 20 are formed by the bright dots 100, and all the dark cells 20. In the second embodiment (two-dimensional symbol 1B shown in FIG. 4), one or two or more dots at the four tops are formed of bright dots 100. This will be described in detail below.

(Two-dimensional symbol of the first embodiment)
For example, as illustrated in FIG. 1, the two-dimensional symbol 1 </ b> A according to the first embodiment includes the dark cells 20 b to 20 h adjacent to at least two continuous sides of the bright cell 10 and the tops of the dark cells 20 b to 20 h that are in a diagonal direction. The dots are formed by bright dots.

  As shown in FIG. 1, the two-dimensional symbol 1 </ b> A includes a contact point 30 and a contact point 32 where the tops of the two bright cells 10 and the tops of the two dark cells 20 are in contact with each other. There is a contact 31 to which the tops of the two dark cells 20 are in contact. Each will be described below.

  The tops of the four cells, the bright cell 10a, the bright cell 10b, the dark cell 20d, and the dark cell 20g, are in contact with each other at the contact point 30. The dark cell 20d and the dark cell 20g are adjacent to two continuous sides of the bright cell 10a and the bright cell 10b, and the top of the dark cell 20d and the top of the dark cell 20g are diagonally connected at the contact 30. Is in contact with That is, using the reference numerals described in FIG. 9, the lower right apex C3 of the dark cell 20d and the upper left apex C1 of the dark cell 20g are in contact with each other in the diagonal direction. In the two-dimensional symbol 1A, one dot at the top C3 of the dark cell 20d and one dot at the top C1 of the dark cell 20g that are in contact with the diagonal direction are formed as bright dots. Therefore, since the dark dots do not contact each other at the contact point 30 where the dark cell 20d and the dark cell 20g contact each other in the diagonal direction, there is no possibility that the inks become familiar and spread.

  The tops of the four cells, the dark cell 20b, the dark cell 20a, the dark cell 20d, and the bright cell 10a, are in contact with each other at a contact point 31. The dark cell 20b and the dark cell 20d are adjacent to two continuous sides of the bright cell 10a, and the top of the dark cell 20b and the top of the dark cell 20d are in contact with each other in the diagonal direction at the contact point 31. In other words, using the symbols described in FIG. 9, the lower left apex C4 of the dark cell 20b and the upper right apex C2 of the dark cell 20d are in contact with each other in the diagonal direction. In the two-dimensional symbol 1A, one dot at the top C4 of the dark cell 20b and one dot at the top C2 of the dark cell 20d that are in contact with the diagonal direction are formed as bright dots. Therefore, since the dark dots do not contact each other at the contact point 31 where the dark cell 20b and the dark cell 20d contact in the diagonal direction, there is no possibility that the inks become familiar and spread.

  Further, although the dot at the top C3 of the dark cell 20a is formed by a dark dot, one dot at the top C4 of the dark cell 20b and the top C2 of the dark cell 20d is formed by a light dot, so the dark cell 20a The dark dots at the top C3 of the other are not in contact with the dark dots at the top of the other dark cells 20. Therefore, there is no possibility that the inks become familiar and spread.

  The tops of the dark cell 20e and the dark cell 20f are in contact with each other at the contact point 32, but the dark cell 20e and the dark cell 20f are not adjacent to the two continuous sides of the bright cell 10, and The top and the top of the dark cell 20f are not in contact with each other in the diagonal direction. For this reason, there is no possibility that the inks will become familiar and spread, and it is not necessary to form the dots at the top of the dark cell 20e and the dark cell 20f with bright dots.

  The two-dimensional symbol 1A has a contact point where the top part of three bright cells 10 and the top part of one dark cell 20 contact each other, and a contact point where the top parts of four bright cells 10 contact each other. Since there is no possibility that the inks of each other become familiar and spread, it is not necessary to make the vertices of the dark cells light dots. Further, at the contact point at which the tops of the four dark cells 20 are in contact, there is no problem caused by the inks becoming familiar and bleeding, so there is no need to make the dark cell apexes light dots.

  When one or more bright dots at the top of the dark cell 20 of the two-dimensional symbol 1A draw a virtual circle inscribed in the dark cell 20, for example, as shown in FIGS. Among the dots that cross, a dot that has an area outside the virtual circle of the dot that is more than half of the area of the dot and a dot that is outside the dot can be used.

  FIG. 2 is an example in which a virtual circle 40 inscribed in the square dark cell 20 of 4 dots × 4 dots of the two-dimensional symbol 1A is drawn. In the dark cell 20, the dark cell 20 d will be described as an example. The virtual circle 40 drawn so as to be inscribed in the four sides of the dark cell 20 d is the dark dot 200 a, the bright dot 100 a, and the top C 3 described in FIG. 9. Crosses the dark dot 200b. The dot whose outer area of the dot virtual circle 40 is more than half of the dot area is the bright dot 100a. That is, the bright dot 100a is divided by the bright dot 100a being crossed by the virtual circle 40. Of the two areas obtained, the area outside the virtual circle 40 is larger than the area inside the virtual circle 40. On the other hand, the dark dot 200a and the dark dot 200b are dots whose area outside the virtual circle 40 of the dot is less than half of the area of the dot.

  FIG. 3 shows an example in which a virtual circle 40 inscribed in the 7-by-7 dot square dark cell 20 of the two-dimensional symbol 1A is drawn. Of the dark cells 20, the dark cell 20d will be described as an example. The virtual circle 41 inscribed in the four sides of the dark cell 20d is the dark dot 200c, the bright dot 100c, the bright dot 100d, and the dark dot at the top C3 described in FIG. Crosses the dot 200d. The bright dot 100c and the bright dot 100d are dots in which the area outside the virtual circle 41 of the dot is more than half the area of the dot. The bright dot 100e is a dot outside the bright dot 100c and the bright dot 100d. On the other hand, the dark dot 200c and the dark dot 200d are dots whose outside area of the virtual circle 41 of the dot is less than half of the area of the dot.

  As described above, the two-dimensional symbol 1 in which two or more dots at the top of the dark cell 20 are formed by light dots is compared with the two-dimensional symbol 1A in which one dot at the top of the dark cell 20 is formed by light dots. In addition, it is possible to prevent the ink from becoming familiar and bleeding. Therefore, the present invention can be preferably applied when the dark cell 20 is formed with a large number of dots, or when the printing medium is made of plastic, metal, or the like that is difficult to fix the ink and is likely to become familiar with each other. Note that when two or more dots at the top of the dark cell 20 are formed as bright dots, the method for determining which dots are bright dots is not limited to this method.

  As described above, according to the two-dimensional symbol 1 </ b> A of the first embodiment, since the inks do not become familiar and spread at the contact points where the dark cells 20 are in contact with each other in the diagonal direction, the ink spreads on the top of the bright cell 10 and the bright cell 10 The conventional phenomenon of reducing the area of the substrate is not caused. As a result, it is possible to prevent a decrease in the reading accuracy of the information of the two-dimensional symbol 1A, and it is not necessary to apply a complicated process or apparatus as in the prior art, and the two-dimensional symbol has a high reading accuracy. 1A can be provided.

(Two-dimensional symbol of the second embodiment)
As shown in FIG. 4, in the two-dimensional symbol 1B of the second embodiment, all the dark cells 20 are formed by forming one or more dots at the four tops with light dots, and dark dots other than the light dots. It is what is formed. That is, in such a two-dimensional symbol 1B, compared to the two-dimensional symbol 1A, there are more places where the dots at the top of the dark cell 20 are formed of bright dots. The pattern of the cell 20 is composed of one type.

  As shown in FIG. 4, the two-dimensional symbol 1 </ b> B includes a contact 30 and a contact 32 where the tops of the two bright cells 10 and the tops of the two dark cells 20 are in contact, and the tops of the one bright cell 10 and 3. There is a contact 31 to which the tops of the two dark cells 20 are in contact. Among these, the contact 30 is the same as the contact 30 of the two-dimensional symbol 1A in FIG.

  In the contact 31, compared to the contact 31 of the two-dimensional symbol 1 </ b> A in FIG. 1, one dot at the top right C <b> 3 of the dark cell 20 a is formed as a bright dot. For this reason, since the dark dots at the tops of the dark cells 20 do not contact each other in the diagonal direction, there is no possibility that the inks become familiar and spread. Even at the contact 32, the dark dots at the top of the dark cells 20 do not contact each other in the diagonal direction, so there is no possibility that the inks will become familiar and spread.

  Such a two-dimensional symbol 1B differs from the two-dimensional symbol 1A in that there is one type of pattern of the dark cell 20, so that the dot at the top of the dark cell 20 is changed to a bright dot depending on how the dark cell 20 is arranged. Since there is no need to perform print control to do, printing can be performed without performing more complicated processing than the two-dimensional symbol 1A.

  Further, since the dark cells 20 of the two-dimensional symbol 1B are formed by the dark dots 200 other than the four dots at the top, it is possible to suppress an increase in the reflectance of the dark cells 20 and to reduce the contrast of the dark cells 20. Can be suppressed.

  In the two-dimensional symbol 1B, as shown in FIG. 5, two or more dots at the top of the dark cell 20 may be formed as bright dots. Since this configuration is the same as that described in FIG. 3 of the “two-dimensional symbol of the first embodiment”, the description is omitted by using the same reference numerals. The effect of this configuration is also the same as the content described in the above “two-dimensional symbol of the first embodiment”, and the description thereof is omitted here.

  When the dark cell 20 is rectangular, one or more bright dots at the top of the dark cell 20 are drawn when a virtual ellipse inscribed in the dark cell 20 is drawn as shown in FIG. Among the dots traversed by the virtual ellipse, the dot can be a dot whose outer area of the virtual ellipse is half or more of the area of the dot and a dot outside the dot. In addition, as shown in FIG. 6B, when two virtual circles inscribed on the three sides of the dark cell 20 are drawn, the virtual circle and the dark cell 20 are surrounded by two continuous sides. Thus, among the dots traversed by the virtual circle, a dot whose outer area of the virtual circle of the dot is half or more of the area of the dot and a dot outside the dot can be used.

  FIG. 6A shows an example in which a virtual ellipse 42 that is inscribed in the four sides of a rectangular dark cell 20 of 8 dots × 10 dots is drawn. The virtual ellipse 42 crosses the dark dot 200e, the bright dot 100f, the bright dot 100g, the dark dot 200f, the bright dot 100i, and the dark dot 200g at the top C2 described in FIG. The bright dot 100f, the bright dot 100g, and the bright dot 100i are dots in which the area outside the virtual ellipse 42 of the dot is half or more of the area of the dot. The bright dot 100h is a dot outside the bright dot 100f, the bright dot 100g, and the bright dot 100i. On the other hand, the dark dot 200e, the dark dot 200f, and the dark dot 200g are dots in which the area outside the virtual ellipse 42 of the dot is less than half of the area of the dot. The ellipse may or may not be an ellipse obtained from the elliptic formula.

  6B shows a rectangular dark cell 20 of 8 dots × 10 dots, a virtual circle 43 inscribed in the three sides on the top and bottom and the left side of the dark cell 20, and a virtual circle 43 ′ on the top and bottom and the right side of the dark cell 20. This is an example in which two virtual circles are drawn. In the top portion C2, the bright dots 100g and the bright dots 100i are regions surrounded by a virtual circle 43 ′, two sides that are formed by one side connecting the top portion C1 and the top portion C2, and one side connecting the top portion C2 and the top portion C3. Among the dots traversed by the virtual circle 43 ′, the dot has an area outside the virtual circle 43 ′ that is more than half the area of the dot. The bright dot 100h is a dot outside the bright dot 100g and the bright dot 100i. On the other hand, the dark dot 200h, the dark dot 200f, and the dark dot 200g are dots in which the area outside the virtual circle 43 'of the dot is less than half of the area of the dot.

  In addition, although the case where the dark cell 20 which comprises the two-dimensional symbol 1B was a rectangle was demonstrated, this structure is applicable similarly even if the dark cell 20 which comprises the two-dimensional symbol 1A of 1st Embodiment is a rectangle. .

  As described above, according to the two-dimensional symbol 1 </ b> B of the second embodiment, the inks do not become familiar and spread at the contact points where the dark cells 20 are in the diagonal direction, so that the ink spreads on the top of the bright cell 10 and the bright cell 10. The conventional phenomenon of reducing the area of the substrate is not caused. As a result, it is possible to prevent a decrease in the reading accuracy of the information of the two-dimensional symbol 1B, and it is not necessary to apply a complicated process or apparatus as in the conventional technique, and the two-dimensional symbol has a high reading accuracy. 1B can be provided.

(Application examples)
As shown in FIG. 7, the application example of the two-dimensional symbol 1 is a two-dimensional symbol 1 in which only one of the dots at the top of the dark cell 20 adjacent in the diagonal direction is formed by the bright dots 100. It is.

  FIG. 7A shows the two-dimensional symbol 1A of the first embodiment shown in FIG. 1 in which the dark cells 20 for each row are composed of normal dark cells 20 formed only of dark dots. That is, the dark cell 20 adjacent to at least two continuous sides of the bright cell 10 is formed by forming one or more dots at the top of the dark cell 20 for each row that are in contact with each other in the diagonal direction. . Further, although not shown, the dark cells 20 for each column may be formed with only dark dots.

  FIG. 7B shows the two-dimensional symbol 1B of the second embodiment shown in FIG. 4 in which the dark cells 20 for each row are formed of normal dark cells 20 formed only of dark dots. That is, the dark cells 20 in each row are formed by forming one or more dots at the four tops with bright dots and forming the dots other than the top dots with dark dots. Further, although not shown, the dark cells 20 for each column may be formed with only dark dots.

  FIG. 7C shows the two-dimensional symbol 1B of the second embodiment shown in FIG. 4, which is composed of only the dark cell 20 in which the dots on both sides of the left side of the dark cell 20 are formed by bright dots. 9, only the dark cell 20 in which the dots on both sides of one side connecting the top part C1 and the top part C4 of the dark cell 20 are formed by bright dots is used. That is, all the dark cells 20 are formed by forming one or more dots on the two tops on both sides of one side among the four tops with bright dots and forming other than the bright dots with dark dots. . In addition, although not shown in figure, you may comprise only the dark cell 20 which formed the dot of the both sides of the one side which connects the top part C1 and the top part C2 of the dark cell 20 with the bright dot, and the top part C2 and the top part C3 of the dark cell 20 are comprised. You may comprise only the dark cell 20 which formed the dot of the both sides of the connecting side by the bright dot, or only the dark cell 20 which formed the dot of the both sides of the one side connecting the top part C3 and the top part C4 of the dark cell 20 by the bright dot. You may comprise.

  As described above, according to the application example of the two-dimensional symbol 1, only one of the dots at the top of the dark cell 20 adjacent in the diagonal direction is formed as a bright dot, so that the dark dot at the top of the dark cells 20 is diagonal. Do not touch the direction. Therefore, there is no possibility that the inks become familiar and spread. Moreover, it can suppress that the reflectance of the dark cell 20 becomes high, and can suppress the fall of the contrast.

  Further, in the application example shown in FIG. 7A, the number of dark cells 20 formed with light dots on the top is about half, so that the top of the dark cell 20 depends on how the dark cells 20 are arranged. It is possible to reduce the work load for performing complicated printing control of making the dots of light dots bright. Further, since the application example shown in FIG. 7B is two types of the dark cell 20 in which the four dots at the top of the dark cell 20 are formed by bright dots, printing can be performed without performing complicated processing. In addition, the application example shown in FIG. 7C can also be printed without performing complicated processing because the pattern of the dark cell 20 is one kind.

[How to print two-dimensional symbols]
The printing method of the two-dimensional symbol 1 according to the present invention is a method of printing the two-dimensional symbol 1 in which the rectangular light cells 10 and the dark cells 20 composed of a plurality of dots shown in FIGS. The dark cell 20 adjacent to at least two continuous sides of the bright cell 10 is printed so that one or more dots at the top of the dark cell 20 that are in contact with each other in the diagonal direction are light dots. And

  On the print medium, ink is applied and printed. The means for printing the two-dimensional symbol 1 is not particularly limited, and examples thereof include means using a toner type or ink jet type printer. Inkjet printers include, for example, an electrostatic drive system that applies and discharges ink from an ink nozzle by increasing or decreasing the volume of an ink chamber that stores ink using electrostatic force, or a heater in an ink nozzle. Although there is a system in which ink is ejected and applied by the pressure of bubbles generated by heating, the present invention can be applied to any inkjet printer. In addition, “ink” as used in the present application includes toner that is used in a toner system in addition to ink that is usually used in an inkjet system.

  The print medium of the two-dimensional symbol 1 is not particularly limited as long as it can be printed, and examples thereof include paper, cloth, plastic, an OHP sheet, and metal.

  Whether the two-dimensional symbol 1 to be printed is the two-dimensional symbol 1A or the two-dimensional symbol 1B is arbitrarily selected in consideration of the number of dots forming the dark cell 20, the control function of the printer, and the like. For example, when the number of dots forming the dark cell 20 is small, the reflectance of the dark cell 20 is higher in the two-dimensional symbol 1A in which a part of the top of the dark cell 20 is formed of bright dots. This is preferable because the decrease in contrast of the dark cell 20 can be further suppressed. In addition, when it is difficult to control the printing position of the dark dots by the control function of the printer, how the dark cells 20 are arranged in the two-dimensional symbol 1B having one kind of dark cell 20 pattern. This is preferable because it is not necessary to perform a complicated process of making the dot at the top of the dark cell 20 a bright dot.

  The dark cell 20 in which two or more dots at the top are printed as light dots, when the dark cell 20 is a square, when a circle inscribed on the four sides of the dark cell 20 is drawn, Among them, a dot whose outer area of the dot circle is half or more of the area of the dot and a dot outside the dot may be printed as bright dots. When the dark cell 20 is rectangular, when an ellipse inscribed on the four sides of the dark cell 20 is drawn, among the dots that the ellipse crosses, the area outside the dot ellipse is half the area of the dot. The above dots and dots outside the dots may be printed as bright dots. Further, when the dark cell 20 is rectangular, when two circles inscribed on the three sides of the dark cell 20 are drawn, in a region surrounded by the circle and the two continuous sides of the dark cell 20, Of the dots traversed by the circle, the dots whose area outside the dot circle is half or more of the area of the dots and the dots outside the dots may be printed as bright dots.

  As described above, according to the printing method of the two-dimensional symbol 1 according to the present invention, the ink does not become familiar and spread at the contact point where the dark cells 20 contact each other in the diagonal direction. The conventional phenomenon of reducing the area of the cell 10 is not caused. As a result, it is possible to prevent a decrease in the reading accuracy of the information of the two-dimensional symbol 1, and it is not necessary to apply a complicated process or apparatus as in the prior art, and the reading accuracy is high. 1 can be provided.

  The present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

[Example 1]
Using a two-dimensional symbol generation software for a personal computer, a bitmap image of a two-dimensional symbol in which the code of “12345678890123456789” is in the DataMatrix format and the size of one cell is 6 dots × 6 dots was created. In all the dark cells 20 constituting the two-dimensional symbol, as in the two-dimensional symbol 1B shown in FIG. 4, one dot at the four tops is formed by the bright dots 100, and dark dots 200 other than the dots at the top are formed. It was supposed to be formed. The above bitmap image was printed by an inkjet printer (Canon Inc., iP4700) with the length of one side of the unit cell being 0.3 mm. The ink is expressed in RGB, and the black color is represented by R (red) = 0, G (green) = 0, and B (blue) = 0 when the lightness of the color is from the minimum value 0 to the maximum value 255. The print medium was white fine paper.

[Example 2]
A two-dimensional symbol was printed in the same manner as in Example 1 except that the ink was blue in RGB notation represented by R = 0, G = 0, and B = 204.

[Example 3]
A two-dimensional symbol was printed in the same manner as in Example 1 except that the two-dimensional symbol was in the QR code format.

[Comparative Example 1]
A two-dimensional symbol was printed in the same manner as in Example 1 except that the dark cell 20 constituting the two-dimensional symbol was a normal dark cell 20 formed of only the dark dots 200.

[Comparative Example 2]
A two-dimensional symbol was printed in the same manner as in Comparative Example 1 except that the ink was blue expressed by R = 0, G = 0, B = 204 in RGB notation.

[Comparative Example 3]
A two-dimensional symbol was printed in the same manner as in Comparative Example 1 except that the two-dimensional symbol was in the QR code format.

[Evaluation]
Using the TruCheck USB CCD remote imager (manufactured by WebScan, Inc.), the two-dimensional symbols printed in Examples 1 to 3 and Comparative Examples 1 to 3 described above are “maximum reflectance”, “minimum reflectance”, “Contrast”, “Modulation”, “Error correction unused rate”, “Decoding” and “Printing accuracy” were evaluated.

  The “maximum reflectance” represents the whiteness of the bright cell 10 and is represented by a value of 0% to 100%. The larger this value, the brighter the cell 10 is. The “minimum reflectance” represents the blackness of the dark cell 20 and is represented by a value of 0% to 100%. It shows that the dark cell 20 is black, so that this value is small. “Contrast” represents the difference between “maximum reflectance” and “minimum reflectance”. The results are shown in Table 1.

  “Modulation” indicates the sharpness of the color tone of the border between the light cell 10 and the dark cell 20, that is, the clarity of the color tone of the border between the light cell 10 and the dark cell 20. Is. Here, “modulation” is represented by a five-level evaluation of “A”, “B”, “C”, “D”, and “F”, where “A” is the closest neighbor of the bright cell 10 and the dark cell 20. This indicates that the color tone of the boundary of the part is sharp, and “B” to “F” indicate that the color tone of the boundary of the adjacent part between the light cell 10 and the dark cell 20 is inferior in that order. ing. The results are shown in Table 1.

  The “error correction unused rate” is an unused rate of a correction function incorporated in advance in a two-dimensional symbol in order to correct a reading abnormality in a part of the two-dimensional symbol. Here, the “error correction unused rate” is expressed by a five-level evaluation of “A”, “B”, “C”, “D”, and “F”, and “A” is a correct two-dimensional symbol. “B” to “F” indicate that the number of defects of the two-dimensional symbol increases in that order. The results are shown in Table 1.

  “Decoding” indicates whether information has been read from the two-dimensional symbol. Here, “decoding” is expressed by two-stage evaluation of “A” and “F”, “A” indicates that information is correctly read from the two-dimensional symbol, and “F” is two-dimensional. Indicates that information could not be read from the symbol. The results are shown in Table 1.

  “Printing accuracy” is determined by determining the lowest evaluation among the above evaluation results as a comprehensive evaluation. Here, “printing accuracy” is represented by a five-step evaluation of “A”, “B”, “C”, “D”, and “F”, and “A” has the highest printing accuracy. “B” to “F” are inferior in “printing accuracy” in that order.

[result]
The “maximum reflectance” and “minimum reflectance” of the two-dimensional symbol of Example 1 are each 1% larger than those of the two-dimensional symbol of Comparative Example 1, and as a result, the “contrast” of both is as follows. It was equivalent. Further, the “error correction unused rate” and “decoding” of the two-dimensional symbol of Example 1 were equivalent to those of the two-dimensional symbol of Comparative Example 1. On the other hand, the “modulation” and “printing accuracy” of the two-dimensional symbol of Example 1 were “A”, whereas the “modulation” and “printing accuracy” of the two-dimensional symbol of Comparative Example 1 were “C”. Yes, “Modulation” and “Printing accuracy” were superior to Example 1.

  The “maximum reflectance” and “minimum reflectance” of the two-dimensional symbol of Example 2 are each 2% larger than the two-dimensional symbol of Comparative Example 1, and as a result, the “contrast” of both is It was equivalent. Further, the “error correction unused rate” and “decoding” of the two-dimensional symbol of Example 2 were equivalent to those of the two-dimensional symbol of Comparative Example 2. On the other hand, the “modulation” and “printing accuracy” of the two-dimensional symbol of Example 2 were “A”, whereas the “modulation” and “printing accuracy” of the two-dimensional symbol of Comparative Example 2 were “B”. Yes, “Modulation” and “Printing accuracy” were superior in Example 2.

  The “maximum reflectance”, “minimum reflectance”, “contrast”, “error correction unused rate”, and “decoding” of the two-dimensional symbol of Example 3 were all equivalent to the two-dimensional symbol of Comparative Example 3. . On the other hand, the “modulation” and “printing accuracy” of the two-dimensional symbol of Example 1 were “A”, whereas the “modulation” and “printing accuracy” of the two-dimensional symbol of Comparative Example 3 were “B”. Yes, “Modulation” and “Printing accuracy” were superior in Example 3.

  From the above results, the “modulation” of the two-dimensional symbols of Examples 1 to 3 was improved as compared with the two-dimensional symbols of Comparative Examples 1 to 3. This is because, in the two-dimensional symbols of Examples 1 to 3, since one dot at the top of each of the dark cells 20 is formed by the bright dots 100, the inks are familiar with each other at the contact point where the dark cells 20 contact each other. This is considered to be because the color tone of the boundary of the adjacent portion between the bright cell 10 and the dark cell 20 became sharper.

  In addition, the two-dimensional symbols of Examples 1 to 3 had the same or larger “maximum reflectance” and “minimum reflectance” than the two-dimensional symbols of Comparative Examples 1 to 3. This is because, in the two-dimensional symbols of Examples 1 to 3, since one dot at the top of each of the dark cells 20 is formed by the bright dots 100, the inks are familiar with each other at the contact point where the dark cells 20 contact each other. This is considered to be because the white color of the bright cell 10 is improved and the black color of the dark cell 20 is reduced. As a result, the “contrast” of the two-dimensional symbols of Examples 1 to 3 and Comparative Examples 1 to 3 are equivalent, and the two-dimensional symbol 1B has one dot at the top of all four dark cells 20 as a bright dot 100. Even if formed, the contrast was equivalent to that of a normal two-dimensional symbol.

  Therefore, the two-dimensional symbol 1B is suppressed in contrast, and the color tone of the boundary between the bright cell 10 and the dark cell 20 is sharp, so that the reading accuracy is higher than that of the conventional two-dimensional symbol. It was expensive.

1, 1A, 1B Two-dimensional symbol 10, 10a, 10b Bright cell 20, 20a, 20b, 20c, 20d, 20e, 20f, 20g, 20h, 20i Dark cell 30, 30 ', 31 Contact 40, 41, 43, 43 'Virtual circle 42 Virtual ellipse 50A, 50B Two-dimensional symbol 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i Bright dot 200, 200a, 200b, 200c, 200d, 200e, 200f, 200g, 200h Dark dot A, A 'Bright cell area C1, C2, C3, C4 Top (corner) dot of dark cell C1', C2 ', C3', C4 'Top (corner) dot of bright cell

Claims (5)

A rectangle and a plurality of bright cells and a rectangle and a plurality of dark cells composed of a plurality of dots are arranged vertically and horizontally, and
Among the plurality of dark cells, dark cells adjacent to at least contiguous two sides of the bright cells, only one or more dots of the top of the dark cells in contact with the diagonal direction are formed in the light dots, dark The dots of the dark cells other than the dots formed on one or more light dots at the top of the cell are formed as dark dots,
Among the plurality of dark cells, a dark cell other than a dark cell adjacent to at least two consecutive sides of the bright cell is a two-dimensional symbol in which all dots constituting the dark cell are dark cells. . One or more bright dots at the top of the dark cell are
When a circle or ellipse inscribed on the four sides of the square or rectangular dark cell is drawn, among the dots traversed by the circle or ellipse, the area outside the circle or ellipse of the dot is more than half of the area of the dot A dot to be and a dot outside the dot, or
When two circles inscribed on the three sides of the rectangular dark cell are drawn, among the dots that the circle crosses in an area surrounded by the circle and the two continuous sides of the dark cell, The two-dimensional symbol according to claim 1 , wherein the area outside the circle is a dot that is more than half of the area of the dot and the dot outside the dot. Among the dark cells, the dark cells for each row or column are formed of only dark dots, or
Wherein all of the dark cell, four of one or more dots of the two top portions on both sides of one side of the top portion is formed in the light dots, except該明dots are formed by dark dots, to claim 1 The described two-dimensional symbol. A printing method of a two-dimensional symbol in which a rectangle and a plurality of bright cells and a rectangle and a plurality of dark cells made of a plurality of dots are arranged vertically and horizontally,
Among the plurality of dark cells, a dark cell adjacent to at least contiguous two sides of the bright cells, Ri only 1 or 2 or more dots of the top of the dark cells in contact with the diagonal direction Do a bright dot, dark The dots of the dark cells other than the dots formed on one or more bright dots at the top of the cell are dark dots,
Among the plurality of dark cells, the bright least dark cells other than the dark cells adjacent to two sides of consecutive cells, wherein all of the dots constituting the dark cell is printed so that such a dark cell 2D symbol printing method. One or more bright dots at the top of the dark cell are
When a circle or ellipse inscribed on the four sides of the square or rectangular dark cell is drawn, among the dots traversed by the circle or ellipse, the area outside the circle or ellipse of the dot is more than half of the area of the dot A dot to be and a dot outside the dot, or
When two circles inscribed on the three sides of the rectangular dark cell are drawn, among the dots that the circle crosses in an area surrounded by the circle and the two continuous sides of the dark cell, 5. The two-dimensional symbol printing method according to claim 4 , wherein the outer area of the circle is a dot that is more than half of the area of the dot, and the dot is outside the dot.