Card reading device and card game fraud detection device

1. A card used in a card game, comprising:

a code including at least two sets of invisible code elements printed on a surface of the card, each set comprising at least two adjacent rows of the invisible code elements,

each of the at least two sets of code elements provided on a respective side of the surface of the card.

2. The card of claim 1 , wherein each set of code elements represents different content.

3. The card of claim 1 , wherein the sets of code elements are spaced from an edge of the card.

4. The card of claim 1 , wherein the code indicates a group code which represents a group to which the card belongs.

5. The card of claim 4 , wherein the group to which the card belongs includes one or more decks of cards.

6. The card of claim 1 , wherein the sets of code elements are printed where no mark is printed.

7. The card of claim 1 , wherein, within each set of code elements, the rows are arranged along a reading direction of a code reader.

8. The card of claim 1 , wherein the sets of code elements are adjacent to each other.

9. The card of claim 1 , wherein the sets of code elements are stacked inwardly from an edge of the card.

10. The card of claim 1 , wherein the code corresponds to an identification number to identify the card.

11. The card of claim 10 , wherein the identification number is unique to each individual card in a deck of cards.

12. The card of claim 11 , wherein the identification number is a binary code.

13. The card of claim 1 , wherein the code indicates the rank and suit of the card.

14. The card of claim 13 , wherein one set of code elements indicates at least a rank of the card.

15. The card of claim 1 , wherein the same code is provided on both sides on the surface of the card along a reading direction of a code reader.