Electronic Dice And Method Of Determining Dice Number Thereof

Abstract

The present invention relates to an electronic dice and a method of determining a dice number. There is provided an electronic dice in which an acceleration sensor and a wired or wireless transmit-receive unit are provided. According to the electronic dice of the present invention, the dice number can be determined and transmitted to an external device based on changes in acceleration values over time, which are detected by the acceleration sensor in accordance with the movement of the dice, thereby combining play of the physical dice with a software game.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention generally relates to a technique of an electronic dice, and more specifically, to an electronic dice of a new type and a method of determining a dice number thereof, in which an acceleration sensor and a transmit-receive unit are provided in a physical polyhedron dice, and the dice number is determined and transmitted to an external device based on changes in acceleration values over time, which are detected by the acceleration sensor in accordance with the movement of the dice, thereby combining play of the physical dice with a software game.

[0003] 2. Description of the Related Art

[0004] When a user plays a game using a dice conventionally, the user first throws the dice. Then, the user confirms a numeral or the number of spots marked on the topmost face of the thrown dice with eyes as a dice number and applies the dice number to the game or play.

[0005] Recently, computers provide a random selection function on behalf of a physical dice. However, since the amusement of throwing a real dice is limited in a dice game using a computer, it has been required to develop a technique capable of combining the action of throwing a real dice with a software game executed in a computer.

[0006] An electronic dice has been proposed in order to meet the requirement, in which electronic devices are embedded in a conventional physical dice, and a dice number obtained by throwing the dice is transmitted to an external electronic device such as a computer.

[0007] For example, the Korean Patent Laid-opened Publication No. 10-2006-0000802 discloses an electronic dice provided with infrared sensors, light emitting devices and an electronic circuit unit inside a physical dice having a cube shape. According to the conventional technique, when the dice is thrown onto a certain bottom surface, the electronic circuit unit provided inside the electronic dice identifies a face of the dice most closely contacted to the bottom surface, automatically determines a numeral or the number of spots on the top face of the dice, and wirelessly transmits a signal corresponding to the numeral or the number of spots to an outside apparatus. However, the conventional technique has a problem in that since each of infrared sensors should be installed into each face of the cubic dice, respectively, the dice has inevitably a complex structure and consumes much power accordingly, and the infrared sensors may function erroneously due to environmental conditions surrounding them.

[0008] In this respect, in the technical field pertinent to the present invention, there is a technical requirement for uniformly detecting a value regardless of external environmental conditions while the sensors and the circuit unit embedded in the electronic dice consume only less power. A sensor that can satisfy the requirement is known to be an inertial sensor capable of detecting the force of inertia from an acceleration applied to a moving object, or an acceleration sensor capable of detecting the change of velocity per a unit time. Recently, these sensors are designed to be miniaturized and consume less power by applying the Micro Electro Mechanical System (MEMS) technique and developed as a multi-axis sensor, and thus the sensors have an optimum condition to be applied to an electronic dice.

[0009] However, since the inertial and acceleration sensors are too sensitive, even a movement such as fine trembling of a hand can be sensed when a user holds an object with the hand, and the sensors malfunction unexpectedly. An example of a technique for solving the problem by a method of correcting errors using a software within a circuit is disclosed in the Korean Patent Publication No. 10-0940095 of "a device for calculating a value of movement of a pointer, a method of correcting a value of movement of a pointer and a 3-dimensional pointing device using the same". According to the above technique, a value sensed by a sensor detecting the slope of a pointer can be corrected using a specific algorithm executed by a processor, and thus it is possible to prevent malfunctions caused by the accumulation of errors generated by unnecessarily sensing fine trembling of a hand.

[0010] However, the above conventional technique for correcting fine trembling of a hand holding a pointer has difficulty in being applied when a dice held in a hand is thrown. Accordingly, it is difficult to apply the technique to an electronic dice as it is, and a new algorithm appropriately applicable to the movement of a thrown dice is required.

[0011] As a result of continued studies on the technique, the inventor has developed an electronic dice comprising an acceleration sensor of miniaturized low-power elements, which can detect the movement of the dice, determine a dice number based on the detection values and transmit the dice number to an external device, and a new algorithm capable of determining the dice number appropriately applicable to the movement of the electronic dice.

SUMMARY OF THE INVENTION

[0012] Accordingly, the present invention is conceived to solve the problems in the prior art as described above. It is an object of the present invention to provide an electronic dice provided with an acceleration sensor therein for transmitting a dice number determined by a new algorithm to an external device, and a method of determining the dice number.

[0013] Specifically, an object of the present invention is to provided an electronic dice of a new type and a method of determining a dice number thereof, in which an acceleration sensor and a wired or wireless transmit-receive unit are provided in a physical polyhedron dice, and the dice number is determined and transmitted to an external device based on changes in acceleration values over time, which are detected by the acceleration sensor in accordance with the movement of the dice, thereby combining play of the physical dice with a software game

[0014] The objects are accomplished by an electronic dice and a method of determining a dice number according to the present invention.

[0015] According to an aspect of the present invention for achieving the objects, there is provided an electronic dice comprising: a main body having a regular polyhedron shape; an acceleration sensor disposed at a center of the main body to sense acceleration values with respect to three perpendicular axes; a control unit for determining that the electronic dice has moved from a stationary state if a displacement of an acceleration value sensed by the acceleration sensor exceeds a predetermined threshold value for a certain period of time, determining a state as a peak detection state if the displacement of the acceleration value over time exceeds a predetermined threshold displacement, determining a state as a stationary state or a completed state where the action of rolling the dice has been completed if the displacement of the acceleration value is smaller than the predetermined threshold value for a certain period of time, and determining a dice number based on the acceleration values sensed in the stationary state or the completed state; and a transmit-receive unit for transmitting the dice number determined by the control unit to an external device.

[0016] The electronic dice according to an embodiment of the present invention may further comprise a memory unit for storing the acceleration values sensed by the acceleration sensor and previously storing numerals of the dice each of which is allocated depending on whether a direction of a top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z. The control unit can determine the direction of the top face of the stationary dice based on the acceleration values sensed with respect to the three axes of X, Y and Z in the stationary or completed state, and determine the dice number by reading said numerals of the dice each of which is allocated depending on whether the direction of the top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z, from the memory unit storing said numerals previously.

[0017] The electronic dice according to an embodiment of the present invention may further comprise an output unit for visually or aurally expressing an operation state of the electronic dice or the operation result for a user.

[0018] In the electronic dice according to an embodiment of the present invention, the acceleration sensor may have a measurement range of .+-.2 g for each axis, and the predetermined threshold displacement for sensing the peak detection state may be 1 g.

[0019] In the electronic dice according to an embodiment of the present invention, the transmit-receive unit is preferably an apparatus capable of communicating through a short-range wireless communication. The transmit-receive unit may be an apparatus capable of communicating with the external device through a short-range wireless communication such as Bluetooth, wireless USB, Zigbee, Infrared Data Association (IrDA), Nordic, SimliciTi or the like. The external device preferably includes all kinds of computing devices provided with a short-range wireless communication means such as a personal computer (PC), a mobile Internet device (MID), a notebook, a netbook, a cellular phone, a smart phone, a smart TV, a conventional TV, an Internet Protocol television (IPTV), a personal digital assistant (PDA) or the like.

[0020] In the electronic dice according to an embodiment of the present invention, the main body of the electronic dice may be a regular tetrahedron, a regular hexahedron, a regular octahedron, a regular dodecahedron, a tetradecahedron, or the like.

[0021] According to another aspect of the present invention, there is provided a method of determining a dice number of an electronic dice, the method comprising the steps of: determining that the electronic dice has moved from a stationary state if a displacement of an acceleration value sensed by an acceleration sensor exceeds a predetermined threshold value for a certain period of time, the acceleration sensor being disposed at a center of a main body of the electronic dice having a regular polyhedron shape, and sensing acceleration values with respect to three perpendicular axes; determining a state as a peak detection state if the displacement of the acceleration value over time exceeds a predetermined threshold displacement; determining a state as a stationary state or a completed state where the action of rolling the dice has been completed if the displacement of the acceleration value is smaller than the predetermined threshold value for a certain period of time; and determining a dice number based on the acceleration values sensed in the stationary state or the completed state, and transmitting the dice number to an external device.

[0022] In the method of determining a dice number of an electronic dice according to an embodiment of the present invention, a direction of a top face of the stationary dice may be determined based on the acceleration values sensed with respect to the three axes of X, Y and Z in the stationary or completed state. The dice number may be determined by reading numerals of the dice each of which is allocated depending on whether the direction of the top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z, from a memory unit storing said numerals previously, and transmitted to the external device.

[0023] The method of determining a dice number of an electronic dice according to an embodiment of the present invention may further comprise visually or aurally expressing an operation state of the each step or the operation result for a user.

[0024] In the method of determining a dice number of an electronic dice according to an embodiment of the present invention, the transmitting of the dice number to the external device may be performed through a short-range wireless communication. For example, the short-range wireless communication may be a short-range wireless communication using Bluetooth, wireless USB, Zigbee, Infrared Data Association (IrDA), Nordic, SimliciTi or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a perspective view showing a schematic internal structure of an electronic dice according to an embodiment of the present invention.

[0026] FIG. 2 is a block diagram showing a configuration example of an internal circuit in an electronic dice according to an embodiment of the present invention.

[0027] FIG. 3 is a flowchart illustrating a method of determining a dice number by detecting movements of an electronic dice according to an embodiment of the present invention.

[0028] FIG. 4 is a graph showing a relationship between changes in acceleration values over time and each detection step in the method of determining a dice number by detecting movements of an electronic dice according to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The following embodiments of the present invention are just to implement the present invention and are not intended to limit or restrict the scope of the present invention. All techniques easily conceivable by those skilled in the art from the detailed descriptions and embodiments of the present invention are interpreted as belonging to the scope of the present invention. The references cited herein are incorporated herein by reference.

[0030] An electronic dice according to an embodiment of the present invention is directed to a physical dice easy to handle capable of being constructed using an acceleration sensor, particularly, using an acceleration sensor manufactured by the MEMS technique for miniaturization and less power consumption.

[0031] In addition, according to the present invention, a dice number can be determined based on the degree of changes of acceleration values on three axes (i.e., the displacement of the acceleration value), in a state of holding a stationary dice with a hand and starting moving the dice, a state of dropping the thrown dice onto a bottom or bumping into an object, and a state of stopping the dropped or bumped dice. The dice number determined as described above may be transmitted to an external device, such as a personal computer (PC), a mobile Internet device (MID), a notebook, a netbook, a cellular phone, a smart phone, a smart TV, a conventional TV, an Internet Protocol television (IPTV), a personal digital assistant (PDA) or the like, through a short-range wireless communication. At this time, the external device may be executing a game software using the transmitted dice number.

[0032] Generally, games executed in a personal computer, a smart phone, a smart TV or the like can be interfaced with a user by various methods. There are various methods for interfacing games with a user. For the methods, a dice capable of generating diverse random numbers are frequently used for inducing user's interests in the games. Currently used computer games operate to adopt a virtual dice by implementing a dice software, and a number selected from the virtual dice is used as a variable of the games. However, from the viewpoint of the user, a conventional method of rolling a physical dice may be preferred.

[0033] Taking into consideration of the above viewpoint, the present invention provides a new interface between a game and a user using an electronic dice for transmitting a dice number to a game executed in a personal computer, a smart phone or a smart TV, the electronic dice being a polyhedron electronic dice for detecting a numeral of the dice using an acceleration sensor.

[0034] As shown in FIG. 1, an electronic dice 10 according to an embodiment of the present invention may comprise an acceleration sensor 17, a battery 15 and a circuit board 13 inside a main body 11 having a cubic shape. The circuit board 13 is preferably configured as a printed circuit board. The battery 15 intervenes between the top and the bottom boards 13, which are disposed at the center of the main body 11 in order to maintain the center of gravity of the electronic dice 10. The acceleration sensor 17 is also placed at the center of the circuit board 13 to measure acceleration values with respect to three axes.

[0035] As is shown in FIG. 2, the acceleration sensor 17 disposed at the center of the circuit board 13 is connected to a control unit 131. The control unit 131 is connected with the battery 15, a memory unit 133, a transmit-receive unit 135 and an output unit 137 to control the operations of the acceleration sensor 17, the memory unit 133, the transmit-receive unit 135 and the output unit 137.

[0036] Although the main body 11 is a cube in the example shown in FIG. 1, it is apparent that it is not limited only to a cube in the present invention. That is, a main body having any regular polyhedron shape may be used in the present invention. For example, the main body 11 may be formed in a regular tetrahedron, a regular hexahedron, a regular octahedron, a regular dodecahedron, a tetradecahedron, or the like.

[0037] The battery 15 supplies electric power for operating the acceleration sensor 17 and the components mounted on the circuit boards 13.

[0038] The acceleration sensor 17 is disposed at the center of the main body 11, i.e., the center of gravity to sense acceleration values of three perpendicular axes, i.e., axis X, axis Y, and axis Z. For example, a three-axis digital acceleration sensor manufactured by any known technique in the art, e.g., the MEMS technique may be used as the acceleration sensor 17.

[0039] For example, an acceleration sensor of model No. CMA3000-D01 (commercially available from VTI Technologies, Inc.) or an acceleration sensor of model No. ADXL345 (commercially available from Analog Devices, Inc.) may be used as the acceleration sensor 17. The acceleration sensor of model No. CMA3000-D01 may have a measurement range of .+-.2 g or .+-.8 g, and the acceleration sensor of model No. ADXL345 may have a measurement range of .+-.2 g, .+-.4 g, .+-.8 g, or .+-.16 g.

[0040] In an embodiment of the present invention, an acceleration sensor having a measurement range of about .+-.2 g for each axis can be used as the acceleration sensor 17. If the acceleration sensor having a measurement range of .+-.2 g has a resolution of 10 bits, the resolution can be converted into a resolution of 4 g/1024 using an ADC, and if the acceleration sensor has a resolution of 12 bits, the resolution can be converted into a resolution of 4 g/4096 using an ADC. However, the present invention is not limited to the exemplary acceleration sensor as described above, and it is apparent that a variety of acceleration sensors known in the art can be used.

[0041] In the example shown in FIG. 1, each of the circuit boards 13 is disposed on the top and bottom of the battery 15, respectively to distribute their weights symmetrically and thus to distribute the whole weight of the electronic dice 10 in circular symmetry with respect to the acceleration sensor 17 disposed at the center of the electronic dice 10.

[0042] The memory unit 133 stores data sensed by the acceleration sensor 17. In addition, the memory unit 133 may store various software commands required to operate the control unit 131, and various reference data such as a threshold value for determining a transition from a stationary state and/or a threshold displacement for determining a peak detection state.

[0043] The transmit-receive unit 135 is a communication means capable of communicating with an external device through a wired communication or a short-range wireless communication such as Bluetooth, wireless USB, Zigbee, Infrared Data Association (IrDA), Nordic, SimliciTi, or the like. For example, a communication protocol of BT, Nordic, SimliciTi or the like may be used as a communication protocol for the wireless communication of the transmit-receive unit 135. Meanwhile, it is apparent that a short-range wireless communication device and/or a communication protocol that can be used in the present invention is not limited to the communication devices and protocols as described above, but those skilled in the art can adopt a variety of short-range wireless communication devices and/or communication protocols used in the field of the present invention.

[0044] The output unit 137 may include, for example, a light emitting diode (LED), a vibrator, a buzzer, or the like, and thus may visually or aurally express the operation state of the dice 10 for a user.

[0045] The control unit 131 can determine a dice number in accordance with the algorithm of the present invention with controlling the operations of the acceleration sensor 17, the memory unit 133, the transmit-receive unit 135 and the output unit 137. The control unit 131 can detect the movement of the dice 10 and determine a dice number based on acceleration values with respect to each of three axes sensed by the acceleration sensor 17 and changes of the acceleration values over time (i.e., the displacement of the acceleration value).

[0046] The movement of the dice 10 detected by the control unit 131 may include four different states such as a stationary state, a peak detection state, a stop detection state, and a completed state. The control unit 131 determines that the dice 10 has been thrown only when the four states are consecutively detected to determine a dice number.

[0047] A method of determining a dice number by the electronic dice 10 according to an embodiment of the present invention configured as described above is shown in FIG. 3 as an example.

[0048] Referring to FIG. 3, if a user holds the electronic dice 10 with a hand and throws the dice 10 on a bottom, the control unit 131 checks acceleration values sensed by the acceleration sensor 17 at certain time intervals, e.g., nanoseconds or microseconds, and determines that the dice 10 is in a stationary state (or a sleep state) if the acceleration values do not exceed a predetermined threshold value, e.g., 1/6 g (S301).

[0049] The acceleration sensor 17 reads acceleration values of three axes of X, Y and Z under the control of the control unit 131 (S302). If a displacement of the read acceleration value exceeds the threshold value (e.g., 1/6 g, approximately corresponding to 10 DAC), the control unit 131 determines that the dice 10 has moved from a stationary state to a moving state (i.e., there is a movement) ("Yes" of S303). This may mean a state in which a user holds the dice 10 with a hand and is about to throw the dice 10, or a state right after a user has thrown the dice 10. On the contrary, if the displacement of the read acceleration value is smaller than the threshold value ("No" of S303), the control unit 131 determines that the dice 10 is still in a sleep state, and the acceleration sensor 17 returns to the step of S302.

[0050] In the case of "Yes" in the step of S303, the acceleration sensor 17 reads changes in acceleration values over time in three axes of X, Y and Z under the control of the control unit 131 (S304). If a displacement of the read acceleration value exceeds a predetermined threshold displacement (e.g., 1 g, approximately corresponding to 70 DAC), the control unit 131 determines that the dice 10 is in a peak detection state (or a high frequency vibration detection state) ("Yes" of S305). This may mean a state in which a user throws the dice 10 and the dice 10 falls onto a bottom or bumps into an object. On the contrary, if the displacement of the read acceleration value is smaller than the threshold displacement ("No" of S305), the acceleration sensor 17 returns to the step of S304 and continues to read changes in acceleration values over time in three axes of X, Y and Z under the control of the control unit 131.

[0051] When detecting a peak (a high frequency vibration), the control unit 131 controls the output unit 137 to express visually or aurally starting of detection for determining a state of the dice 10, i.e., a dice number for a user (S306). For example, the LED visually emits light, or the buzzer generates a certain beep sound, and thus a user may recognize starting of a dice game.

[0052] Subsequently, the acceleration sensor 17 continues to periodically read changes in acceleration values over time in three axes of X, Y and Z under the control of the control unit 131 (S307). If a displacement of the acceleration value is smaller than the threshold value for a certain period of time, the control unit 131 determines that the dice 10 is in a stationary or a completed state ("Yes" of S308). If the displacement of the read acceleration value is not smaller than the threshold value ("No" of S308), the acceleration sensor 17 returns to the step of S307 and continues to periodically read changes in acceleration values over time in three axes of X, Y and Z.

[0053] In the case of "Yes" in the step of S308, the control unit 131 determines that the action of rolling the dice 10 is completed and thus controls the output unit 137 to express visually or aurally the stationary or completed state where the movement of the dice 10 is stopped for a user (S309). Then, the control unit 131 determines a dice number (a numeral) based on the acceleration values sensed in the stationary or completed state and transmits the dice number to an external device through the transmit-receive unit 135 (S310).

[0054] For example, the memory unit 133 previously stores numerals of the dice each of which is allocated depending on whether a direction of a top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z. The control unit 131 can determine the direction of the top face of the stationary dice based on the acceleration values sensed with respect to the three axes of X, Y and Z in the stationary or completed state, and determine the dice number by reading said numerals of the dice each of which is allocated depending on whether the direction of the top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z, from the memory unit 133 storing said numerals previously.

[0055] FIG. 4 is a graph showing a relationship between changes in acceleration values over time and each detection step in the method of determining a dice number by detecting movements of an electronic dice according to an embodiment of the present invention. In the graph of FIG. 4, acceleration values detected with respect to each of three axes of X, Y and Z are expressed as curves of different colors, respectively. In the example of FIG. 4, the horizontal axis is a time axis where a unit time having a time length of about 1/30 second is represented from 1 to 246. In addition, the vertical axis represents acceleration values in a range of .+-.150 digital acceleration (DAC) where 10 DAC corresponds to approximately 1/6 g. In this case, the acceleration values are converted into DAC values, assuming that the acceleration sensor has a measurement range of .+-.2 g and a resolution of 8 bits. In the detailed description of the specification, "g" denotes an acceleration of gravity.

[0056] Reviewing changes in acceleration values over time as shown in FIG. 4, it is seen that there are four separate dice states along the time axis.

[0057] The first state is a stationary (sleep) state (see a unit time [1:15]), and it is understood that there is no substantial change in acceleration values of the three-axis acceleration sensor. This is a state before the movement of the dice is detected. The transition from a stationary state to a moving state (i.e., there is a movement) can be determined based on the threshold value stored in the memory unit 133. The control unit 131 controls the memory unit 133 to maintain an average of the acceleration values sensed by the acceleration sensor 17 in the memory unit 133. The control unit 131 controls the acceleration sensor 17 to periodically check the acceleration values sensed by the acceleration sensor 17. If a displacement of the average acceleration value exceeds the threshold value (e.g., 10-DAC, approximately corresponding to 1/6 g) and the displacement of the average acceleration value exceeding the threshold value is maintained for a certain period of time (e.g., 1 second), it may be determined that there is a movement and the dice has moved from a stationary state.

[0058] The second state is a peak detection state (see a unit time [16:156]). The peak detection state includes a transition state from the stationary state where a displacement of an acceleration value of the three-axis acceleration sensor exceeds the threshold value. In the peak detection state, a high frequency component (i.e., a phenomenon that a displacement of an acceleration value over time abruptly increases) can be detected as shown in FIG. 4 (see a unit time [136:156]). If the dice falls onto a bottom or bumps into an object, the acceleration value abruptly changes, and thus the high frequency component is occurred as a frequency component of tens of Hz (e.g., 10 to 30 Hz) or more with its amplitude of 1 g or more (corresponding to approximately 70 DAC). In the present invention, a high-pass filter may be additionally provided on the circuit board 13 of the electronic dice 10 or embedded in the acceleration sensor as one chip, and a cut-off frequency of the high-pass filter may be set to the aforesaid high frequency. Accordingly, if the amplitude of the frequency component occurred and detected as described above is more than the threshold displacement (e.g., 1 g) stored in the memory unit 133, the control unit 131 determines this phenomenon as a peak detection. After a peak is detected, the control unit 131 controls the dice to progress toward a stop detection state, considering a phenomenon that the dice stops spontaneously after the peak detection.

[0059] The third state is a stop detection state (see a unit time [156:171]). In this state, the acceleration sensor 17 determines whether all the displacements of the acceleration values sensed by the three-axis acceleration sensor drop below the threshold value (e.g., 10-DAC), under the control of the control unit 131. If all the displacements of acceleration values of the three axes detected by the acceleration sensor 17 are smaller than the threshold value, the control unit 131 controls the dice to progress toward a completed state, considering a phenomenon that the dice stops slowly and gradually even after the stop detection.

[0060] The fourth state is a completed state (see a unit time [171:246]). In this state, the acceleration sensor 17 detects whether the displacement of the acceleration value dropped less than the threshold value is maintained for a certain period of time (e.g., 3 seconds), under the control of the control unit 131. If the control unit 131 determines that the dice is in a completed state based on the detection of the acceleration sensor 17, it searches for an axis showing a certain acceleration value, for example, .+-.1 g among the three-axis acceleration values of the acceleration sensor 17. In the example of FIG. 4, since the acceleration value of axis X is -1 g (corresponding to approximately -48 DAC) in the completed state, the control unit 131 can determine that the top face of the dice is on axis +X thus and a numeral thereof is "3". Accordingly, the control unit 131 can inform the external device of the result of the determination, i.e, "3".

[0061] In this regard, the memory unit 133 previously stores numerals of the dice each of which is allocated depending on whether a direction of a top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z. Accordingly, the control unit 131 can determine a dice number, according to the axis direction and/or the corresponding direction of the top face of the stationary dice, based on the data of the memory unit 133 and the acceleration values of the acceleration sensor 17.

[0062] For example, the memory unit 133 may store numerals of the top face of the stationary dice in accordance with each of axis directions corresponding to three-axis acceleration values of the acceleration sensor 17 (See an example as below).

Example

[0063] Dice numeral 1: axis direction.fwdarw.-Z, in this case, the acceleration value of the acceleration sensor of axis Z is -1 g;

[0064] Dice numeral 6: axis direction.fwdarw.+Z, in this case, the acceleration value of the acceleration sensor of axis Z is +1 g;

[0065] Dice numeral 3: axis direction.fwdarw.-X, in this case, the acceleration value of the acceleration sensor of axis X is -1 g;

[0066] Dice numeral 4: axis direction.fwdarw.+X, in this case, the acceleration value of the acceleration sensor of axis X is +1 g;

[0067] Dice numeral 2: axis direction.fwdarw.+Y, in this case, the acceleration value of the acceleration sensor of axis Y is +1 g; and

[0068] Dice numeral 5: axis direction.fwdarw.-Y, in this case, the acceleration value of the acceleration sensor of axis Y is -1 g.

[0069] Accordingly, the control unit 131 can determine a dice number, according to the axis direction and/or the corresponding direction of the top face of the stationary dice, based on the aforesaid data of the memory unit 133 and the acceleration values of the acceleration sensor 17.

[0070] Meanwhile, although acceleration sensor values with respect to three axes in the completed state and a numeral on the topmost face of the dice stopped after being thrown may be determined in the method as described above, this is only an example, and a dice number of the topmost face of the dice may be determined in a variety of methods based on acceleration values sensed in the completed state.

[0071] The present invention as described above in which an acceleration sensor and a wired or wireless transmit-receive unit are provided has the effect that a dice number can be determined and transmitted to an external device based on changes in acceleration values over time, which are detected by the acceleration sensor in accordance with the movement of the dice, thereby combining play of the physical dice with a software game.

[0072] Although preferred embodiments of the present invention have been described, the present invention is not limited thereto. It will be apparent that those skilled in the art can make various modifications and changes thereto without departing from the spirit and scope of the present invention and the modifications and changes are also included in the scope of the present invention.

Claims

1. An electronic dice, comprising: a main body having a regular polyhedron shape; an acceleration sensor disposed at a center of the main body to sense acceleration values with respect to three perpendicular axes; a control unit for determining that the electronic dice has moved from a stationary state if a displacement of an acceleration value sensed by the acceleration sensor exceeds a predetermined threshold value for a certain period of time, determining a state as a peak detection state if the displacement of the acceleration value over time exceeds a predetermined threshold displacement, determining a state as a stationary state or a completed state where the action of rolling the dice has been completed if the displacement of the acceleration value is smaller than the predetermined threshold value for a certain period of time, and determining a dice number based on the acceleration values sensed in the stationary state or the completed state; and a transmit-receive unit for transmitting the dice number determined by the control unit to an external device.

2. The dice as claimed in claim 1, further comprising a memory unit for storing the acceleration values sensed by the acceleration sensor and previously storing numerals of the dice each of which is allocated depending on whether a direction of a top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z.

3. The dice as claimed in claim 2, wherein the control unit determines the direction of the top face of the stationary dice based on the acceleration values sensed with respect to the three axes of X, Y and Z in the stationary or completed state, and determines the dice number by reading said numerals of the dice each of which is allocated depending on whether the direction of the top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z, from the memory unit storing said numerals previously.

4. The dice as claimed in claim 1, further comprising an output unit for visually or aurally expressing an operation state of the electronic dice or the operation result for a user.

5. The dice as claimed in claim 1, wherein the acceleration sensor has a measurement range of .+-.2 g for each axis, and the predetermined threshold displacement for sensing the peak detection state is 1 g.

6. The dice as claimed in claim 1, wherein the transmit-receive unit is an apparatus capable of communicating with the external device through a short-range wireless communication using Bluetooth, wireless USB, Zigbee, Infrared Data Association (IrDA), Nordic, or SimliciTi.

7. A method of determining a dice number of an electronic dice, comprising: determining that the electronic dice has moved from a stationary state if a displacement of an acceleration value sensed by an acceleration sensor exceeds a predetermined threshold value for a certain period of time, the acceleration sensor being disposed at a center of a main body of the electronic dice having a regular polyhedron shape, and sensing acceleration values with respect to three perpendicular axes; determining a state as a peak detection state if the displacement of the acceleration value over time exceeds a predetermined threshold displacement; determining a state as a stationary state or a completed state where the action of rolling the dice has been completed if the displacement of the acceleration value is smaller than the predetermined threshold value for a certain period of time; and determining a dice number based on the acceleration values sensed in the stationary state or the completed state, and transmitting the dice number to an external device.

8. The method as claimed in claim 7, wherein a direction of a top face of the stationary dice is determined based on the acceleration values sensed with respect to the three axes of X, Y and Z in the stationary or completed state, and the dice number is determined by reading numerals of the dice each of which is allocated depending on whether the direction of the top face of the stationary dice is +X, -X, +Y, -Y, +Z or -Z, from a memory unit storing said numerals previously, and transmitted to the external device.

9. The method as claimed in claim 7, further comprising visually or aurally expressing an operation state of the each step or the operation result for a user.

10. The method as claimed in claim 7, wherein the acceleration sensor has a measurement range of .+-.2 g for each axis, and the predetermined threshold displacement for sensing the peak detection state is 1 g.

11. The method as claimed in claim 7, wherein the transmitting of the dice number to the external device is performed through a short-range wireless communication using Bluetooth, wireless USB, Zigbee, Infrared Data Association (IrDA), Nordic, or SimliciTi.