Patent Description:
In various playing card games such as poker, baccarat, bridge, and blackjack, a dealer sets playing cards of one deck or a plurality of decks on a card shooter and the like, delivers the playing cards one by one from the card shooter, and distributes the playing cards to a game participant. At this time, in order to guarantee fairness of the game, these cards need to be distributed randomly, so a game sponsor needs to sufficiently shuffle the playing cards randomly before setting the playing cards on the card shooter.

However, when the game sponsor performs shuffling prior to the game, it may take a long time to shuffle cards, which is a factor of hindering an efficient operation of a game. In addition, when the game sponsor performs shuffling, there is a problem in that there is room to perform fraudulent acts such as inserting and removing cards and replacing cards.

In order to solve such a problem, <CIT> discloses shuffled playing cards individually packaged in a state in which playing cards constituting a predetermined number of decks are shuffled. In the packaging of the shuffled playing card, a shuffled playing card ID for accessing information, which can specify a shuffle machine or a shuffle machine group shuffling the shuffled playing card, on database is assigned as an ID code.

Originally, in a printing industry, it is essential to use a carbon black ink in addition to three primary colors, in order to express sharper and darker black in a black part. Naturally, even in the case of the playing card, it is common sense to normally print the black part with the carbon black ink. The prior art document <CIT> discloses a system and method of combining two playing card values, sight unseen, and displaying which of multiple ranges that the total falls into, without displaying the actual total or the actual values of either card. The prior art document <CIT> discloses a dot pattern on which code information and x and y coordinate information can be defined even if the dot pattern is extremely small.

Carbon has characteristics that infrared emissivity (absorption ratio) is high, so the carbon black ink will appear black when viewed through an infrared camera.

In recent years, ultra-miniaturization and high performance of electronic devices have been advanced, and even the infrared camera with good performance can be made ultra-miniaturized by malicious fraudulent players, so that there is a risk that the camera will be brought from the outside into a game hall without being noticed.

When a normal playing card is viewed through an infrared camera with good performance, a printed part on a front side to which the carbon black ink is applied can be seen even from a back side of the playing card. That is, there is a possibility to identify ranks and suits on the front side when viewed from the back side.

An object of the present invention is to provide a playing card capable of making it difficult to see through a printed part on a front side even when the playing card is viewed through an infrared camera.

The present invention provides a solution to the above mentioned problems according to the independent claims. Preferred embodiments are provided by the dependent claims. There is provided a playing card according to an aspect of the present invention, wherein.

According to this aspect, since the card base sheet is provided with an infrared seeing-through preventing layer containing the carbon as the intermediate layer, infrared rays radiated from the printed part on the front side of the card are absorbed by the intermediate layer, and hardly transmit the back side of the card. In addition, since the ink containing no carbon is used to print the suit and the rank, a difference between intensity of infrared rays radiated from the printed part and intensity of infrared rays radiated from an area therearound is small. Thus, it is extremely difficult to distinguish the suit and the rank from a distribution of a trace amount of transmitted infrared rays even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer. Therefore, it is possible to provide a playing card capable of making it difficult to see through the printed part on the front side even when the playing card is viewed through the infrared camera.

In the playing card according to the aspect of the present invention,
the back pattern on the back surface of the card base sheet may be printed with an ink containing carbon.

According to the aspect, since the back pattern of the card is printed with an ink containing carbon, the infrared distribution having the same pattern as the back pattern appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern of the card, so it is even more difficult to distinguish the printed part on the front side of the card even when the playing card is viewed through the infrared camera.

There is provided a playing card according to an aspect of the present invention, wherein.

According to this aspect, since the card base sheet is provided with the infrared seeing-through preventing layer containing the carbon as the intermediate layer, infrared rays radiated from the front side of the card are absorbed by the intermediate layer, and hardly transmit the back side of the card. In addition, since the back pattern of the card is printed with the ink containing carbon, the distribution of the infrared rays having the same pattern as the back pattern appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern of the card, so it is extremely difficult to distinguish the suit and the rank from the distribution of the infrared rays. Therefore, it is possible to provide a playing card capable of making it difficult to see through the printed part on the front side even when the playing card is viewed through the infrared camera.

According to the aspect, since the ink containing no carbon is used to print the suit and the rank, a difference between intensity of infrared rays radiated from the printed part and intensity of infrared rays radiated from an area therearound is small. Thus, it is extremely difficult to distinguish the suit and the rank from a distribution of a trace amount of transmitted infrared rays even if there are the infrared rays radiated from the printed part on the front side of the card and the infrared rays transmitting the back side of the card. In addition, since the back pattern of the card is printed with the ink containing carbon, the distinct uneven distribution of the infrared rays having the same pattern as the back pattern appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern of the card, so it is extremely difficult to distinguish the suit and the rank from the distribution of the infrared rays. Therefore, it is possible to provide a playing card capable of making it difficult to see through the printed part on the front side even when the playing card is viewed through the infrared camera.

There is provided a shuffled playing card according to an aspect of the present invention, wherein
a predetermined sets of playing cards having any of the above-described characteristics are shuffled by a shuffle machine to form a set of shuffled playing cards, and the set of shuffled playing cards is individually packaged and sealed.

According to the aspect, it is possible to provide a shuffled playing card which need not be shuffled by a game sponsor over a long period of time prior to a game and does not provide any room to perform fraudulent acts such as inserting and removing cards and replacing cards.

In the shuffled playing card according to the aspect of the present invention,
individually different shuffled playing card IDs may be assigned to the shuffled playing card individually packaged and sealed as ID codes.

According to the aspect, for example, if the shuffled playing card ID is associated with information that can specify the shuffle machine or a shuffle machine group shuffling the shuffled playing card, the shuffled playing card ID is assigned to the shuffled playing card individually packaged and sealed, and thus when it is conceived that there is any defect in the playing card and the shuffle machine is a cause of the defect, it is possible for a manufacturer to easily specify in which shuffle machine or shuffle machine group the defect occurs, thereby making it possible to take countermeasures as soon as possible.

In the playing card according to the aspect of the present invention,.

According to this aspect, since the card base sheet on which the different sheet IDs are printed for one card base sheet or each of the plurality of card base sheets is cut to produce the playing card of one deck or a plurality of decks, it is possible to confirm, on the database, the information on when the card is printed and also when the card is inspected by tracing back through the distribution history of the playing card. As a result, it is possible to confirm whether the playing card is a genuine product correctly manufactured and distributed by reading the sheet ID from the contents of the card to confirm the history on the database even if the contents of the packaged shuffled playing card are replaced with a set of cards whose arrangement is known by malicious fraudulent players.

In a shuffled playing card according to the aspect of the present invention,.

In the playing card according to the aspect of the present invention,
the back pattern of the card base sheet may be printed with an ink containing carbon to allow the ink containing carbon of the back pattern to prevent the transmission of the infrared rays from the back surface.

In the playing card according to the aspect of the present invention,
the intermediate layer may prevent the infrared rays including the carbon from seeing-through.

There is provided a shuffled playing card according to an aspect of the present invention, wherein
predetermined sets of the playing cards having any one of the above characteristics may be shuffled by a shuffle machine to form a set of shuffled playing cards.

In the shuffled playing card according to an aspect of the present invention,
individually different shuffled playing card IDs may be assigned to the shuffled playing cards as ID codes.

A table game system according to an aspect of the present invention includes:.

In the respective drawings, constituent elements having equivalent functions are denoted by the same reference numerals, and the detailed description of the constituent elements denoted by the same reference numerals is not repeated.

The table game system according to one embodiment includes a playing card <NUM> having a suit 21a and a rank 21b printed on one surface thereof (see <FIG>), a game table which plays a game using the playing card <NUM>, and a card distribution device which withdraws the playing card <NUM> in the game table sheet by sheet.

As will be described later, the suit 21a and the rank 21b are printed on the playing card <NUM> with ink containing no carbon. In addition, the playing card <NUM> is printed with a code indicating the suit 21a and the rank 21b with invisible ink (for example, ultraviolet light emitting ink which emits light by irradiation of ultraviolet light or DNA containing paint which emits light having a specific wavelength with respect to light).

The card distribution device has a function of allowing the code or the rank printed with the invisible ink to read and determining and displaying win or loss results of each game based on the information of the rank. As the card distribution device, for example, a card shooter device described in <CIT> or a card shooter device described in <CIT> can be used.

Next, the structure of the playing card <NUM> according to one embodiment will be described. <FIG> is an exploded view of a playing card <NUM> according to one embodiment. <FIG> is an enlarged view of a part of a cross section of the playing card <NUM> shown in <FIG>.

As shown in <FIG>, the playing card <NUM> according to the present embodiment has the suit 21a and the rank 21b printed on one surface thereof, a back pattern <NUM> printed on the back surface thereof, and an infrared seeing-through preventing layer <NUM> as an intermediate layer.

In the present embodiment, the infrared seeing-through preventing layer <NUM> as the intermediate layer contains carbon. Since the carbon has characteristics that infrared emissivity (absorption ratio) is high, as shown in <FIG>, the infrared rays irradiated from the printed part (for example, sheet ID <NUM> to be described later) of the front surface of the card are absorbed by the infrared seeing-through preventing layer <NUM> as the intermediate layer and hardly transmit the back side of the card. In the present specification, the term "visible ray" means radiation that can enter the eyes and generate visual sensation and the term "infrared ray" means radiation which has a wavelength of a monochromatic light component longer than that of visible radiation (visible rays) and shorter than about <NUM>, which are based on the definition of JIS Z <NUM>: <NUM>.

The infrared seeing-through preventing layer <NUM> is not limited to an aspect including a material such as carbon which absorbs infrared rays as long as it can prevent the transmission of infrared rays. For example, the infrared seeing-through preventing layer <NUM> may be an aspect including a material such as aluminum foil which reflects infrared rays.

In the playing card <NUM> according to the present embodiment, ink containing no carbon is used for the printed part of the suit 21a and the rank 21b. The use of the ink containing no carbon is out of common sense, but since a jet black is not required for the rank and the suit or the pattern of the playing card, there is no problem even if the ink containing no carbon is used. Since the ink containing no carbon is used for the printed part of the suit 21a and the rank 21b, the difference between intensity of infrared rays radiated from the printed parts 21a and 21b and intensity of infrared rays radiated from an area therearound is small. Thus, it is extremely difficult to distinguish shapes of the suit 21a and the rank 21b from a distribution of a trace amount of transmitted infrared rays even if there are the infrared rays radiated from the printed parts 21a and 21b on the front side of the card and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer <NUM>.

In the playing card <NUM> according to the present embodiment, the back pattern <NUM> of the card is printed with the ink containing carbon (for example, carbon black ink). For this reason, as shown in <FIG>, the distribution of the infrared rays having the same pattern as the back pattern <NUM> appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part (for example, sheet ID <NUM>) on the front side and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer <NUM>, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern <NUM> of the card, so it is even more difficult to distinguish the printed part <NUM> on the front side of the card even when the playing card is viewed through the infrared camera.

<FIG> is a diagram showing the front surface of the card <NUM> constituting a set of decks among playing cards <NUM> according to one embodiment, and <FIG> is a diagram showing the back surface of the card. <FIG> is a diagram showing a front surface of a card <NUM> other than the card constituting a set of decks among the playing cards <NUM> according to one embodiment, and <FIG> is a diagram showing a back surface of the card.

As shown in <FIG>, a set of playing cards <NUM> according to the present embodiment has <NUM> × <NUM> = <NUM> cards which are constituted by a combination of four suits 21a (that is, spade, club, diamond, and heart) and <NUM> ranks 21b (that is, ace (A), <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, jack (J), queen (Q), and king (K)) as a card <NUM> constituting a set of decks.

In addition, as shown in <FIG>, the set of playing cards <NUM> according to the present embodiment further has a "joker" card <NUM> as a card other than the cards constituting the set of decks. The "joker" card <NUM> included in one set of playing cards <NUM> may be one sheet or two sheets. The "joker" card <NUM> is a card which is removed and discarded before a shuffling process at the time of producing a shuffled playing card to be described later.

The set of playing cards <NUM> and <NUM> according to the present embodiment are formed by being individually cut from one card base sheet <NUM> (see <FIG>) by a cutting machine.

As shown in <FIG>, common sheet IDs <NUM> and <NUM> are printed on front surfaces of each of the set of playing cards <NUM> and <NUM>, and a common back pattern <NUM> is printed on a back side thereof. The sheet IDs <NUM> and <NUM> may be a character code including a plurality of figures, alphabets, or symbols, or may be a bar code or a two-dimensional code in which the character code is encoded.

As shown in <FIG>, the sheet ID <NUM> printed on the card <NUM> constituting the set of decks may be printed with ink (for example, transparent UV ink) invisible to human eyes, or may be printed with ink (for example, black ink) visible to human eyes. When the sheet ID <NUM> is printed with ink (for example, transparent UV ink) invisible to human eyes, the appearance becomes similar to that of the conventional card, and thus a user of the card can use the card without feeling uncomfortable. On the other hand, when the sheet ID <NUM> is printed with ink (for example, black ink) visible to the human eyes, although there is a possibility that the user of the card may feel uncomfortable, the sheet ID <NUM> is simply an ID code, and therefore it does not cause special problems in the game.

In addition, as shown in <FIG>, the sheet ID <NUM> printed on a card <NUM> other than the card constituting the set of decks may be printed with ink (for example, transparent UV ink) invisible to human eyes, or may be printed with ink (for example, black ink) visible to human eyes. When the card printed with ink (for example, black ink) visible to human eyes, a manufacturer can easily confirm the sheet ID <NUM> in the manufacturing process to be described later when inspecting quality of the printed card base sheet.

As shown in <FIG>, the sheet IDs <NUM> and <NUM> printed on the respective playing cards <NUM> and <NUM> are stored in the database in association with one or both of recording of a printing date of the sheet ID on the original card base sheet <NUM> and recording of a cut date on the individual playing cards <NUM> and <NUM>.

<FIG> is a diagram showing a shuffled playing card <NUM> according to the present embodiment, and is a diagram showing the shuffled playing card <NUM> before a package <NUM> is sealed with a seal <NUM>. <FIG> is a diagram showing the shuffled playing card <NUM> according to the present embodiment, and is a diagram showing the shuffled playing card <NUM> in which a shuffled playing card ID 13a is assigned to the seal <NUM> for sealing the package <NUM>.

The shuffled playing card <NUM> according to the present embodiment is a card in which a plurality of decks (for example, four decks or eight decks) of the card <NUM> constituting the deck among the above-described playing cards <NUM> are one set, and is sufficiently shuffled by a shuffle machine. In the shuffled playing card <NUM>, different shuffled playing card IDs 13a are assigned as ID codes for each set. In the shown example, the shuffled playing card <NUM> is housed in a box-shaped package <NUM> and a lid thereof is sealed with a seal <NUM>. The shuffled playing card ID 13a is encoded as a bar code and printed on the seal <NUM> which seals the package <NUM>.

As shown in <FIG>, the sheet ID <NUM> of the playing card <NUM> constituting the shuffled playing card <NUM> and the shuffled playing card ID 13a are stored in the database in association with each other. In addition, in the example shown in <FIG>, the shuffled playing card ID 13a and a shuffle machine ID and a shuffle date which specify a shuffle machine or a shuffle machine group shuffling the shuffled playing card <NUM> are stored in database in association with each other.

Next, a method of manufacturing a playing card <NUM> and a shuffled playing card <NUM> according to the present embodiment will be described. <FIG> is a flowchart showing a method of manufacturing a playing card <NUM> and a shuffled playing card <NUM> according to the present embodiment.

In the manufacturing process of the playing card <NUM> and the shuffled playing card <NUM> according to the present embodiment, it is preferable for a process management system to consistently perform process management from order to shipment. In the present embodiment, a manufacturing method using such a process management system will be described.

First, the card base sheet <NUM> having the infrared seeing-through preventing layer <NUM> as the intermediate layer is prepared. As shown in <FIG> and <FIG>, as a printing process, the printing machine prints the suit 21a and the rank 21b on the front surface of the card base sheet <NUM>, and prints the back pattern <NUM> on the back surface thereof (step S40). In the present embodiment, the ink containing no carbon is used for printing the suit 21a and the rank 21b. In addition, the ink containing carbon is used for printing the back pattern <NUM>.

In the example shown in <FIG>, a total of <NUM> cards including <NUM> cards <NUM> including a combination of four suits and <NUM> ranks, one "joker" card <NUM>, and three other cards <NUM> are printed in a matrix arrangement of <NUM> rows × <NUM> columns.

As one modification, as shown in <FIG>, a total of <NUM> cards including two decks of <NUM> cards <NUM> including a combination of four suits and <NUM> ranks and one other card <NUM> may be printed in a matrix arrangement of <NUM> rows × <NUM> columns.

Next, as a sheet ID assigning step, the process management system assigns different sheet IDs to each card base sheet or the plurality of card base sheets and the printing machine prints the sheet IDs <NUM> and <NUM> on the front surface of the card base sheet <NUM> (step S41). In addition, by the process management system, the sheet IDs <NUM> and <NUM> and the printing dates of the sheet IDs <NUM> and <NUM> on the card base sheet <NUM> are stored in the database in association with each other (see <FIG>). Although not shown in the drawing, the sheet IDs <NUM> and <NUM> may be stored in the database in association with one or two or more of a factory name, a manufacturing line, a customer name (casino name).

In the present embodiment, the sheet ID <NUM> is printed on the card <NUM> constituting a set of decks with ink (for example, transparent UV ink) invisible to human eyes. As a result, the card <NUM> constituting the set of decks has the same appearance as a conventional card, and thus the user of the card can use the card without feeling uncomfortable. It should be noted that the sheet ID <NUM> may be printed only on a specific card (for example, spade A) among the cards <NUM> constituting the set of decks, or may be printed on all the cards.

On the other hand, the sheet ID <NUM> is printed on the cards <NUM> and <NUM> other than the card constituting the set of decks with ink (for example, black ink) visible to human eyes. As a result, when the manufacturer can easily confirm the sheet ID when inspecting the quality of the printed card base sheet.

In the present embodiment, the sheet ID assigning process (step S41) is performed after the printing process (step S40), but the present embodiment is not limited thereto, and the printing process (step S40) may be performed after the sheet ID assigning process (step S41).

Next, the card base sheet <NUM> having undergone the printing process (step S40) and the sheet ID assigning process (step S41) is cut into individual cards <NUM>, <NUM>, and <NUM> by the cutting machine (step S42). By removing cards <NUM> and <NUM> other than the cards constituting the set of decks from the cut card, the playing card <NUM> corresponding to one deck (corresponding to two decks from the card base sheet <NUM> shown in <FIG>) is produced.

The sheet ID <NUM> is read from the playing card <NUM> constituting the set of decks by the process management system before being shuffled or during being shuffled by the shuffle machine to be described later and is stored in the database in association with the shuffle machine (or shuffle machine group) and shuffled date and time (see <FIG>).

Next, as the shuffling process, the plurality of decks (for example, four decks or eight decks) of playing card <NUM> are shuffled by the shuffle machine, and the set of shuffled playing cards <NUM> is produced (step S43). As the shuffle machine, for example, the shuffle machine described in <CIT> can be used.

Next, the set of shuffled playing cards <NUM> which has undergone the shuffling process (step S43) is packaged by a packaging machine (step S44). In the present embodiment, as shown in <FIG>, the set of shuffled playing cards <NUM> is housed in the box-shaped package <NUM>. The material of the package <NUM> is not particularly limited, and may be paper or a resin film. As shown in <FIG>, the lid of the package <NUM> is sealed with the seal <NUM>.

Next, different shuffled playing card IDs are generated for each set of shuffled playing cards by the process management system, and the shuffled playing card ID 13a is assigned to the set of shuffled playing cards <NUM> as the ID code (step S45). In the shown example, the shuffled playing card ID 13a is encoded as the bar code and is printed on the seal <NUM> sealing the lid of the package <NUM> by the printing machine.

In the shown example, in addition to the shuffled playing card ID 13a, a specification table 13b is printed on the seal <NUM>. For example, arbitrary information such as a manufacturing number, a product number, a product name, a color, and a manufacturing date of the shuffled playing card is described in the specification table 13b.

Further, by the process management system, the sheet ID <NUM> read from the playing card <NUM> constituting the set of decks before the shuffling process (step S43) is stored in the database in association with the shuffled playing card ID 13a of the set of shuffled playing cards <NUM> to which the deck belongs (see <FIG>). In the shown example, the set of shuffled playing cards <NUM> are configured from the playing cards <NUM> corresponding to four decks, and four sheet IDs <NUM> are stored in the database in association with each shuffled playing card ID 13a. In addition, by the process management system, in the database, the shuffled playing card ID 13a and the shuffle machine ID and the shuffle date which specify the shuffle machine or the shuffle machine group shuffling the shuffled playing card <NUM> are stored in the database in association with each other.

According to the present embodiment, as shown in <FIG>, since the card base sheet <NUM> is provided with the infrared seeing-through preventing layer <NUM> containing the carbon as the intermediate layer, the infrared rays radiated from the printed part on the front side of the card are absorbed by the intermediate layer <NUM>, and hardly transmit the back side of the card. In addition, since the ink containing no carbon is used to print the suit 21a and the rank 21b, a difference between intensity of infrared rays radiated from the printed part and intensity of infrared rays radiated from an area therearound is small. Thus, it is extremely difficult to distinguish the suit 21a and the rank 21b from a distribution of a trace amount of transmitted infrared rays even if there are the infrared rays radiated from the printed part on the front side of the card and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer <NUM>. Therefore, it is possible to provide a playing card <NUM> capable of making it difficult to see through the printed part on the front side even when the printed part on the front side is viewed through the infrared camera.

In addition, according to the present embodiment, since the back pattern <NUM> on the back surface of the card base sheet <NUM> is printed with the ink containing carbon, as shown in <FIG>, the distribution of the infrared rays having the same pattern as the back pattern <NUM> appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side of the card without being absorbed by the intermediate layer <NUM>, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern <NUM> of the card, so it is even more difficult to distinguish the printed part on the front side of the card even when the playing card is viewed through the infrared camera.

In addition, according to the present embodiment, since the predetermined sets of playing cards <NUM> described above are shuffled by the shuffle machine to form a set of shuffled playing cards <NUM> and a set of shuffled playing cards <NUM> is packaged and sealed individually, it is possible to provide a shuffled playing card which need not be shuffled by a game sponsor over a long period of time prior to a game and does not provide any room to perform fraudulent acts such as inserting and removing cards and replacing cards.

In addition, according to the present embodiment, since different shuffled playing card IDs 13a are individually assigned, as ID codes, to the shuffled playing card <NUM> individually packaged and sealed, for example, as shown in <FIG>, if the shuffled playing card ID 13a is associated with information that can specify the shuffle machine or the shuffle machine group shuffling the shuffled playing card <NUM>, when it is conceived that there is any defect in the playing card and the shuffle machine is a cause of the defect, it is possible for a manufacturer to easily specify in which shuffle machine or shuffle machine group the defect occurs, thereby making it possible to take countermeasures as soon as possible.

In addition, according to the present embodiment, since the card base sheet <NUM> on which the different sheet ID <NUM> are printed for one card base sheet <NUM> or each of the plurality of card base sheets <NUM> is cut to produce the playing card of one deck or a plurality of decks, it is possible to confirm, on the database, the information on when the card is printed and also when the card is inspected by tracing back through the distribution history of the playing card <NUM>. As a result, it is possible to confirm whether the playing card is a genuine product correctly manufactured and distributed by reading the sheet ID <NUM> from the contents of the card to confirm the history on the database in units of sheet even if the contents of the packaged shuffled playing card <NUM> are replaced with a set of cards whose arrangement is known by malicious fraudulent players.

In addition, by printing different sheet IDs <NUM> for each card base sheet <NUM> or the plurality of card base sheets <NUM>, the ID management of the card base sheet <NUM> in the factory becomes possible. For example, even when the card base sheet <NUM> is discarded halfway, it is possible to manage at which step the playing card is discarded in the database. In this way, it is possible to grasp a yield in each process at the manufacturing stage. In addition, it will be able to be understood whether the card of the card base sheet which is determined to be defective in each process and thus discarded is inadvertently mixed in goods (that is, it will be able to be understood whether only cards of good card base sheet are used for goods). In addition, even if malicious fraudulent players illegally obtain the discarded card base sheet <NUM> and cut the obtained card base sheet by themselves to produce a counterfeit card and bring the produced counterfeit card for use in a game, the sheet ID <NUM> is read from the card to confirm the history on the database, thereby making it possible to easily detect that the playing card is a counterfeit card and enhance the security of the game.

In addition, in the above-described embodiment, in the sheet ID assigning step, as shown in <FIG> and <FIG>, the sheet IDs <NUM> and <NUM> are printed on a part of the card base sheet <NUM> on which the cards <NUM> to <NUM> are printed, but the present embodiment is not limited thereto, and the sheet ID may also be printed on a part of the card base sheet <NUM> on which the card is not printed. In this case, it is possible to acquire the sheet ID from the remaining part (so-called punching scrap) after removing the cards <NUM> to <NUM> from the card base sheet <NUM>.

In addition, in the above-described embodiment, (<NUM>) in addition to the fact that the card base sheet <NUM> has the infrared seeing-through preventing layer <NUM> as the intermediate layer, (<NUM>) the ink containing no carbon is used to print the suit 21a and the rank 21b, (<NUM>) furthermore, the back pattern <NUM> on the back surface of the card base sheet <NUM> is printed with the ink containing carbon, but (<NUM>) in addition to the fact that the card base sheet <NUM> has the infrared seeing-through preventing layer <NUM> as the intermediate layer, (<NUM>) when the ink containing no carbon is used to print the suit 21a and the rank 21b, (<NUM>) the back pattern <NUM> on the back surface of the card base sheet <NUM> is not necessarily printed with the ink containing carbon, and the back pattern <NUM> may also be printed with the ink containing no carbon.

Further, (<NUM>) the ink containing no carbon is used to print the suit 21a and the rank 21b, and (<NUM>) furthermore, when the back pattern <NUM> on the back surface of the card base sheet <NUM> is printed with the ink containing carbon, (<NUM>) the card base sheet <NUM> does not necessarily have the infrared seeing-through preventing layer <NUM> as the intermediate layer, and the card base sheet <NUM> may not have the infrared seeing-through preventing layer <NUM> as the intermediate layer. Even in the aspect, since (<NUM>) the ink containing no carbon is used to print the suit 21a and the rank 21b, the difference between intensity of infrared rays radiated from the printed part and intensity of infrared rays radiated from an area therearound is small. For example, it is extremely difficult to distinguish the suit 21a and the rank 21b from a distribution of a trace amount of transmitted infrared rays even if there are the infrared rays radiated from the printed part on the front side of the card and the infrared rays transmitting the back side of the card. In addition, since the back pattern <NUM> of the card is printed with the ink containing carbon, the distribution of the infrared rays having the same pattern as the back pattern <NUM> appears on the back side of the card. Therefore, even if there are the infrared rays radiated from the printed part on the front side and the infrared rays transmitting the back side, the distribution of the trace amount of transmitted infrared rays is buried by overlapping the distribution of the infrared rays radiated from the back pattern <NUM> of the card, so it is extremely difficult to distinguish the suit 21a and the rank 21b from the distribution of the infrared rays. Therefore, even in the aspect, it is possible to provide a playing card capable of making it difficult to see through the printed part on the front side even when the playing card is viewed through the infrared camera.

<FIG> is a diagram showing a cross section of a conventional playing card <NUM>. Since visible rays <NUM> and infrared rays <NUM> transmit the conventional playing card <NUM>, there was a problem in that it is possible to distinguish printing <NUM> indicating a rank or a suit from the back surface.

<FIG> is a diagram showing a cross section of a playing card <NUM> having an intermediate layer <NUM> added to the conventional playing card <NUM>. The playing card <NUM> includes the intermediate layer <NUM> having a black layer or a color layer similar to black to prevent the transmission of the visible rays <NUM> and make it difficult for the visible rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface. However, since the infrared rays <NUM> have a strong transmitting force and transmit the intermediate layer <NUM>, there was a problem in that the printing <NUM> indicating the rank or the suit still can be distinguished from the back surface by using the infrared rays <NUM>.

<FIG> is a diagram showing a cross section of a playing card <NUM> according to an embodiment. The playing card <NUM> according to the present embodiment includes the intermediate layer <NUM> having the black layer or the color layer similar to black, and furthermore, the ink containing no carbon is used for printing <NUM> indicating a rank or a suit. First, the playing card <NUM> includes the intermediate layer <NUM> having a black layer or a color layer similar to black to prevent the transmission of the visible rays <NUM> and make it difficult for the visible rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface. The infrared rays <NUM> transmit the intermediate layer <NUM>, but furthermore, the ink containing no carbon is used for the printing <NUM> indicating the rank or the suit, so the infrared rays <NUM> transmit the printing <NUM> indicating the rank or the suit and it is difficult for even the infrared rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface. As described above, in the playing card <NUM> according to the present embodiment, it is difficult for both of the visible rays <NUM> and the infrared rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface.

<FIG> is a diagram showing a cross section of a playing card <NUM> according to another embodiment of the present invention. The playing card <NUM> according to another embodiment includes an intermediate layer <NUM> having a black layer or a color layer similar to black, and furthermore, the ink containing no carbon is used for the printing <NUM> indicating the rank or the suit. In addition, the intermediate layer <NUM> contains carbon. The intermediate layer <NUM> having the black layer or the color layer similar to black prevents the transmission of the visible rays <NUM>, and the intermediate layer <NUM> containing the carbon reduces the transmission amount of the infrared rays <NUM>. The infrared rays <NUM> do not completely stop at the intermediate layer <NUM> and some of the infrared rays transmit the intermediate layer <NUM>, but furthermore, the ink containing no carbon is used for the printing <NUM> indicating the rank or the suit, so the infrared rays <NUM> transmit the printing <NUM> indicating the rank or the suit and it is difficult for even the infrared rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface. As described above, the playing card <NUM> of another embodiment of the present invention further reduces the amount of the infrared rays <NUM> transmitting the intermediate layer <NUM> than the playing card <NUM>, so it is difficult for both of the visible rays <NUM> and the infrared rays <NUM> to distinguish the printing <NUM> indicating the rank or the suit from the back surface.

Claim 1:
A gaming card (<NUM>) used in a game, comprising:
a first layer of a card base sheet (<NUM>) on which a pattern representing a type of the gaming card (<NUM>) is printed; and
a second layer with a back surface on which a back pattern (<NUM>) common to a plurality of the gaming cards (<NUM>) is printed,
wherein the pattern representing a type of the gaming card (<NUM>) is printed using an ink containing no carbon to allow the pattern representing a type of the gaming card (<NUM>) printed by the ink containing no carbon to transmit infrared rays (<NUM>), such that it is difficult to distinguish the type of the gaming card (<NUM>) from the back surface using visible rays (<NUM>) and infrared rays (<NUM>).