Roulette gaming machine and method for selecting constant rotation period

A roulette gaming machine comprises a roulette board, a ball, a rotatable portion, ball receiving parts, numerals, a driving motor and a main control CPU. The rotatable portion is rotatably provided at a center portion of the roulette board. The ball receiving parts receives the ball and circularly arranged on an inner periphery side of the rotatable portion. The numerals are circularly arranged on an outer periphery side of the rotatable portion so as to be opposed to the ball receiving parts respectively. The driving motor rotates the rotatable portion in a certain direction. The main control CPU selects a drive control pattern. The main control CPU varies a constant speed rotation period for rotating the rotatable portion at a certain rotation speed according to the drive control pattern, and controls the driving unit according to the constant speed rotation period and the certain rotation speed.

CROSS REFERENCE TO RELATED APPLICATION

This application claims benefit of priority under 35 U.S.C. §119 to Japanese Patent Application No. 2005-185458, filed on Jun. 24, 2005, the entire contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a roulette gaming machine configured to cause a ball to roll on a roulette board and the rolling ball to be received into one of ball receiving parts formed on a rotatable portion. More specifically, the roulette gaming machine causes the rolling ball to be received into one of the ball receiving parts while varying a period for rotating the rotatable portion at a fixed rotation speed according to a lottery result. The present invention further relates to a method for selecting a constant speed rotation period for rotating the rotatable portion.

2. Description of the Related Art

There have been conventionally various roulette gaming machines. When a player bets one or more game media on one or more desired numerals arranged on a roulette board, the roulette gaming machine causes a roulette wheel (rotatable portion) of the roulette board to rotate at a fixed rotation speed and during a fixed period. Then, a ball is launched to the roulette board and then rolls on the roulette board. If the roulette wheel slowly rotates, the rolling ball is received into one of ball receiving grooves (ball receiving parts) formed on the roulette wheel. The roulette gaming machine identifies one numeral (winning number) assigned to the ball receiving groove in which the ball is received, and then determines whether or not the one numeral is equal to one of the one or more desired numerals bet on by the player. If the one numeral is equal to one of the one or more desired numerals, the roulette gaming machine pays out game media corresponding to a dividend amount.

The conventional roulette gaming machine rotates the roulette wheel, in order to vary the winning number as randomly as possible by each roulette game to prevent skilled players from predicting the winning number surely. However, since the roulette wheel is rotated at the fixed rotation speed and during the fixed period in each roulette game, the skilled players can roughly predict a next winning number on the basis of the arrangement of the roulette wheel at the time of launching the ball.

A conventional method for solving the above-described problem is disclosed in Japanese Patent Laid-open Publication No. 2003-334275. In the conventional method, a rotation speed of a roulette wheel is varied according to a sampled random number when a certain time has elapsed since the ball is launched. It is noted that the ball is retrieved from a fixed position of the roulette wheel after the ball has been received in a ball receiving groove formed on the roulette wheel, and then launched from a fixed postion of the roulette board.

However, the conventional method needs a complicated drive control process for a motor to be employed to rotate the roulette wheel because the rotation speed of the roulette wheel is randomly varied in each roulette game. Further, in a case where a pseudo random number generating circuit is employed in the conventional method, if skilled players obtain the previous winning number, the tendency for random numbers to be generated by the pseudo random number generating circuit, and the rotation speed of the roulette wheel corresponding to each random number in each roulette game, they can roughly predict a next winning number because the arrangement of the roulette wheel is reset in each roulette game so that the ball receiving groove to which the previous winning number is assigned is located at the fixed position of the roulette wheel every time the ball is retrieved.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide a roulette gaming machine configured to easily and surely prevent skilled players from roughly predicting a winning number in comparison with the conventional roulette gaming machines.

It is another object of the present invention to provide a method for selecting a constant speed rotation period which is capable of easily and surely preventing skilled players from roughly predicting a winning number in comparison with the conventional method.

In order to achieve the object, the present invention provides a roulette gaming machine comprising: a roulette board; a ball rolling on the roulette board; a rotatable portion formed into an annular shape and rotatably provided at a center portion of the roulette board; a plurality of ball receiving parts configured to receive the ball and circularly-arranged on an inner periphery side of the rotatable portion; a plurality of marks circularly-arranged on an outer periphery side of the rotatable portion so as to be opposed to the plurality of ball receiving parts respectively; a bank passage provided on an outer periphery of the roulette board and on which the ball rolls along a circumferential orbit; a driving unit configured to rotate the rotatable portion in a certain direction; a selecting unit configured to select one drive control pattern among a plurality of drive control patterns for the driving unit; and a rotation period variation control unit configured to vary a constant speed rotation period for rotating the rotatable portion at a certain rotation speed according to the one drive control pattern, and then control the driving unit according to the constant speed rotation period and the certain rotation speed.

According to the present invention, the roulette gaming machine does not need a complicated drive control process for the driving unit because the constant speed rotation period instead of a rotation speed is varied in each roulette game. Therefore, the roulette gaming machine can easily and surely prevent skilled players from roughly predicting a winning number, in comparison with the conventional roulette gaming machine.

In order to achieve the object, the present invention provides a method for selecting a constant speed rotation period for rotating a rotation portion having a plurality of ball receiving parts configured to receive a ball launched by a ball launching unit in a roulette gaming machine, the method comprising the steps of: reading a previous winning number; generating a pseudo random number; selecting a constant speed rotation period according to the generated pseudo random number; and compensating the selected constant speed rotation period according to a positional relation between a ball receiving part to which the previous winning number is assigned and a ball receiving part opposed to the ball launching unit, the positional relation generated when the rotatable portion stops rotating in a previous roulette game.

According to the present invention, even if skilled players obtain the previous winning number, the tendency for pseudo random numbers, and the constant speed rotation period corresponding to each pseudo random number, they cannot roughly predict a next winning number because the tendency for pseudo random numbers is disturbed by chaos caused when a ball rolls on a roulette board in the previous roulette game.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, one exemplary embodiment of the present invention will be described with reference toFIGS. 1 to 22.

A roulette gaming machine is a gaming machine configured to allow a player to play a roulette game. More specifically, the roulette gaming machine pays out the certain number of game media such as medals to a player when a roulette device selects among a plurality of numerals one numeral on which the player has bet one or more game media.

As shown inFIG. 1, a roulette gaming machine1comprises a roulette device2, a cabinet3, a plurality of satellites4, a plurality of medal payout slots8, a plurality of speakers9and an electronic display unit77. The cabinet3forms a main body of the roulette gaming machine1. The roulette device2is mounted in a center portion of the cabinet3.

The satellites4are mounted on an upper periphery portion of the cabinet3. It is noted that twelve satellites4are mounted on the cabinet3in the present exemplary embodiment. Each satellite4comprises a medal insertion slot5, a control portion6and an image display device7. A player can insert one or more game media such as medals or bills into the medal insertion slot5. The medal insertion slot5has a medal sensor97(seeFIG. 12) therein. The medal sensor97detects and counts the game media inserted into the medal insertion slot5. A player can input various instructions into the roulette gaming machine1by using a plurality of control buttons mounted on the control portion6. The image display device7displays various images associated with a roulette game thereon. The roulette game proceeds when a player operates the control portion6while watching the image display device7.

The medal payout slots8are mounted on a lower periphery portion of the cabinet3. Each medal payout slot8has a hopper94(seeFIG. 12) therein. The hopper94pays out the certain number of game media via the medal payout slot8when a player operates the control portion6.

The speakers9are mounted on the upper periphery portion of the cabinet3. The roulette gaming machine1makes an effective sound via the speakers9. The satellite4, the medal payout slot8and the speaker9make a set in the roulette gaming machine1. It is noted that twelve sets are mounted on the periphery portion of the cabinet3in the present exemplary embodiment.

The electronic display unit77is mounted on an upper portion of the cabinet3. The electronic display unit77has a jackpot value display78at the top thereof. The jackpot value display78displays a jackpot value generated by accumulating a certain percentage (e.g. 0.5%) of the amount of total credits which have been bet by all players participating in the roulette game by means of the satellites4. All players who participate in the roulette game can have visual contact with the jackpot value display78because the jackpot value display78is mounted at the top of the electronic display unit77.

As shown inFIG. 2, the roulette device2comprises a roulette board12, a support table13, a compressor14, air tubes15,16, a first valve17and a second valve18. The roulette board12has thereon a rolling area on which a ball11rolls during a roulette game. The roulette board12is supported on the support table13in the roulette device2. The compressor14takes in surrounding air and compresses the surrounding air by a constant pressure (1 Mpa in the present exemplary embodiment). Then, the compressor14discharges the compressed air to the roulette board12via the air tubes15,16. The first valve17is mounted at a center portion of the air tube15and adjusts air pressure within the air tube15. The second valve18is mounted at a center portion of the air tube16and adjusts air pressure within the air tube16.

The roulette board12comprises a rotatable portion20, a rim21and a center fixed portion22. The rotatable portion20and the rim21form the rolling area. The rim21has a bottom panel21A at a lower portion thereof (seeFIG. 4). The center fixed portion22substantially forms into a circular cone and is fixedly supported on the bottom panel21A of the rim21. The rotatable portion20substantially forms into an annular bank and is rotatably supported by the center fixed portion22. The rotatable portion20has an inner periphery surface abutting on an outer periphery surface of the center fixed portion22. The rim21substantially forms into an annular bank and is fixedly supported on the support table13. The rim21has an inner periphery surface abutting on an outer periphery surface of the rotatable portion20. The rotatable portion20has a plurality of concave ball receiving parts23(thirty-eight ball receiving parts in the present exemplary embodiment) arranged on an inner periphery side of an upper surface thereof and along a circumferential direction thereof. The ball receiving parts23are adjacent to one another via party walls23A each which substantially forms into a triangle (seeFIG. 6). The rotatable portion20further has a number indication part24arranged on the upper surface thereof and along a circumferential direction thereof so as to surround the ball receiving parts23. In the number indication part24, numerals “0”, “00”, “1” to “36” are respectively arranged to areas which are opposed to the ball receiving parts23. Each of the areas is painted red or black.

The rectangular support table13is made by assembling a plurality of metal columns one another. The support table13fixedly supports the roulette board12by means of fixing tools41mounted on four corners of an upper portion thereof. The roulette board12is thereby located at a certain height.

The compressor14is arranged within the support table13. The compressor14has a discharge nozzle42for discharging the compressed air. The discharge nozzle42is connected to the air tubes15,16. The air tubes15,16are respectively connected to a first outlet portion33and second outlet portions36mounted on the roulette board12(seeFIG. 3).

The first and second valves17,18are magnetic valves and capable of controlling an opening valve time. The first and second valves17,18are connected to a main control CPU80(seeFIG. 11). The main control CPU80controls the opening valve time according to a program stored in a ROM81in advance. The main control CPU80can thereby adjusts air pressure to be discharged from the first and second outlet portions33,36via the first and second valves17,18, which causes the ball11to roll on the roulette board12during a certain time.

When the roulette device2is installed in the roulette gaming machine1, the roulette board12is covered with a semispherical cover member25which is made of transparent acrylic (seeFIG. 1). The cover member25prevents the rolling ball11from getting out of the roulette board12during a roulette game. The cover member25further prevents foreign matter from getting into the roulette board12, which leads to prevent deceptive acts.

More specifically, the configuration of the roulette board12will be described with reference toFIGS. 3 to 5.

The roulette board12comprises the rotatable portion20, the rim21and the center fixed portion22. As shown inFIG. 4, the rotatable portion20is rotatably supported by the center fixed portion22via a cross ball bearing26. The rotatable portion20is rotated by a driving motor34mounted in the roulette board12, at a certain speed (e.g. 5.005 rpm or 16.683 rpm) and in a certain direction (e.g. an anticlockwise direction) with respect to the rim21. The rotation of the rotatable portion20starts at a certain time before the ball11will be launched from one of the ball receiving parts23and finishes at a certain time after the ball11has been received in one of the ball receiving parts23.

In a case where the ball11has been received in the ball receiving part23, the ball receiving part23is located at the front of the first outlet portion33by rotating the rotatable portion20, so that the ball11is launched from the ball receiving part23. Also, in a case where the ball11has been received in the ball receiving part23, the ball receiving part23passes the front of one of ball detecting sensors44mounted on the center fixed portion22by rotating the rotatable portion20, so that the ball receiving part23is detected by one of the ball detecting sensors44. A rotation driving mechanism and rotating operation of the rotatable portion20will be described later.

The rim21has a bank passage29around an outer periphery portion thereof. The bank passage29guides the rolling ball11in a circumferential direction of the rim21, against centrifugal force acting on the rolling ball11. The ball11thereby rolls on a circular orbit. The bank passage29is formed by a guide wall30and an upper wall31. The guide wall30vertically extends from the outer periphery portion of the rim21. The upper wall31inward and horizontally extends from an upper end portion of the guide wall30. The upper wall31prevents the rolling ball11from getting out of the bank passage29.

When the ball11is launched from one of the ball receiving parts23, the launched ball11starts to roll by air discharged from the second outlet portions36. Then, the ball11rolls on the bank passage29while accelerating in the circumferential direction of the rim21by the discharged air. In this state, when discharging air from the second outlet portions36is stopped, the rolling ball11decelerates to lose the centrifugal force acting thereon. Then, the ball11rolls down a first slope surface28B of the rim21to reach the rotating rotatable portion20. Further, the ball11rolls on the number indication part24of the rotating rotatable portion20and then is received into one of the ball receiving parts23. One numeral arranged to the area opposed to the one of ball receiving parts23becomes a winning number.

As shown inFIG. 5, the value of the depth L of the ball receiving part23with respect to a bottom surface of the ball receiving part23is smaller than the value of the diameter D of the ball11. This allows participating players to easily identify the ball11received in the ball receiving part23from every angle, during a roulette game. In the number indication part24, a second slope surface (bottom surface)28A inward extends from the first slope surface28B of the rim21(seeFIG. 4). An oblique angle α of the first slope surface28B is equal to that of the second surface28A. This also allows the participating players to easily identify the ball11received in the ball receiving part23from every angle, during the roulette game. The first and second slope surfaces28B,28A form a whole slope surface28. Thereby, the ball11is launched and smoothly rolls toward the bank passage29on the whole slope surface28.

The ball receiving parts23are detachably fixed to the rotatable portion20by means of screws38so that maintenance of respective ball receiving parts23is easily conducted. The screws38are driven into the bottom surfaces of all the ball receiving parts23, respectively. Here, it would appear that a convex upper portion of each screw38interferes with entry of the ball11into the ball receiving part23, which would influence probability for the entry of the ball11into the ball receiving part23. However, the interference occurs with equal probability in all the ball receiving parts23, which does not influence the probability while increasing diversity of ball trajectories.

Next, the configuration of the first outlet portion33will be described with reference toFIGS. 3 to 6.

As shown inFIGS. 3,4, the first outlet portion33is fixedly supported by a clamping plate27mounted at an outer periphery edge of the center fixed portion22which is opposed to the rotatable portion20. The compressor14generates compressed air and feeds the compressed air into the roulette board12through the air tube15and the first outlet portion33.

Each ball receiving part23has an inner wall37on which a circular air pass hole35is formed (seeFIG. 6). In the present exemplary embodiment, since the rotatable portion20has thirty-eight ball receiving parts23, thirty-eight air pass holes35are formed. Before the ball11is launched from the ball receiving part23(ball receiving part opposed to the area to which the numeral “21” is arranged inFIG. 6), the ball receiving part23is located at the front of the first outlet portion33by rotating the rotatable portion20. Then, the ball11is launched by the compressed air discharged through the first outlet portion33and the air pass hole35and rolls on the whole slope surface28toward the bank passage29.

Next, the configuration of the second outlet portions36will be described with reference toFIGS. 3,4,7.

As shown inFIGS. 3,7, the second outlet portions36are formed in the guide wall30at certain intervals (45° intervals in the present exemplary embodiment). More specifically, each second outlet portion36is formed in the guide wall30along a tangential direction of the roulette board12so as to generate air-flow along a circumferential direction of the bank passage29(seeFIG. 21).

A semicircular air pipe39is installed on a back surface of the guide wall30. The air pipe39is connected to the air tube16and the second outlet portions36. The compressor14also generates compressed air and feeds the compressed air into the air pipe39through the air tube16to discharge the compressed air into the roulette board12through the second outlets36.

When the launched ball11reaches the bank passage29, the ball11rolls on the bank passage29while accelerating in the circumferential direction of the bank passage29by the air discharged from the second outlets36. In this state, when discharging air from the second outlet portions36is stopped, the rolling ball11decelerates to lose the centrifugal force acting thereon. Then, the ball11rolls down the first slope surface28B of the rim21to reach the rotating rotatable portion20. Further, the ball11rolls on the number indication part24of the rotating rotatable portion20and then is received into one of the ball receiving parts23.

Next, various sensors employed in the roulette board12will be described with reference toFIGS. 3,8.

The ball detecting sensors44are fixedly supported by the clamping plate27mounted at the outer periphery edge of the center fixed portion22which is opposed to the rotatable portion20. The ball detecting sensors44are arranged at certain intervals (about 120 intervals in the present exemplary embodiment). Each ball detecting sensor44is a reflective light sensor and comprises a light emitting element for emitting infrared rays and a light receiving element for receiving the infrared rays reflected by any objects. Therefore, the ball detecting sensor44can detect the ball11received in the ball receiving part23opposed thereto via the air pass hole35. It is noted that each ball detecting sensor44may be a transmissive light sensor and comprise a light emitting element arranged to the bank passage29and a light receiving element arranged to the center fixed portion22opposed to the light emitting element.

An identification sensor57and a rotation sensor58are also fixedly supported by the clamping plate27. The identification sensor57detects a specific identification plate (not shown) mounted to the ball receiving part23opposed thereto. The rotation sensor58detects whether or not the rotatable portion20rotates.

A method for identifying one numeral (winning number) arranged to the area opposed to the ball receiving part23in which the ball11is received will be described.

In the present exemplary embodiment, thirty-eight ball receiving parts23surrounds the center fixed portion22. Each ball receiving part23has an identification plate mounted on a back surface of the inner wall37thereof. The identification plate has a specific corrugated pattern corresponding to one numeral arranged to the area which is opposed to the ball receiving part23.

In a condition that the first outlet portion33, three ball detecting sensors44, the identification sensor57and the rotation sensor58are simultaneously opposed to the ball receiving parts23, these members are arranged to the center fixed plate22along an anticlockwise direction of the center fixed plate22as follows (seeFIG. 3): the ball receiving part23opposed to the first ball detecting sensor44(1st) is arranged at intervals of thirteen ball receiving parts from the ball receiving part23opposed to the third ball detecting sensor44(3rd); the ball receiving part23opposed to the second ball detecting sensor44(2nd) is arranged at intervals of thirteen ball receiving parts from the ball receiving part23opposed to the first ball detecting sensor44(1st); the ball receiving part23opposed to the third ball detecting sensor44(3rd) is arranged at intervals twelve ball receiving parts from the ball receiving part23opposed to the second ball detecting sensor44(2nd); the ball receiving part23opposed to the first outlet portion33is arranged at intervals of six ball receiving parts from the ball receiving part23opposed to the second ball detecting sensor44(2nd); the ball receiving part23opposed to the identification sensor57is arranged at intervals of seven ball receiving parts from the ball receiving part23opposed to the first ball detecting sensor44(1st); and the ball receiving part23opposed to the rotation sensor58is arranged at intervals of five ball receiving parts from the ball receiving part23opposed to the first ball detecting sensor44(1st). The numerals are arranged on the number indication part24along an anticlockwise direction of the number identification part24as the follows: “0”, “2”, “14”, “35”, “23”, “4”, “16”, “33”, “21”, “6”, “18”, “31”, “19”, “8”, “12”, “29”, “25”, “10”, “27”, “00”, “1”, “13”, “36”, “24”, “3”, “15”, “34”, “22”, “5”, “17”, “32”, “20”, “7”, “11”, “30”, “26”, “9” and “28”. The above member arrangements are previously stored in the ROM81as a member arrangement table. It is noted that the above member arrangements may be replaced with another member arrangements.

When the ball11is received in one of the ball receiving parts23, one of the ball detecting sensors44detects the one ball receiving part23, and at the same time, the identification sensor57detects the identification plate mounted to the ball receiving part23opposed thereto while the rotation sensor58detects the rotation of the rotatable portion20. The main control CPU80reads the member arrangement table from the ROM81and then identifies one numeral (winning number) corresponding to the ball receiving part23in which the ball11is received with reference to the read member arrangement table (see S20inFIG. 17) because a positional relation between the identification sensor57and the one of the ball detecting sensor44has been defined in the member arrangement table.

When next roulette game is started, the identification sensor57detects the identification plate mounted to the ball receiving part23opposed thereto. Then, the main control CPU80identifies the numeral corresponding to the detected identification plate, and determines whether or not the ball receiving part23in which the ball11is received is located at the front of the first outlet portion33on the basis of the previous winning number, the identified numeral and the member arrangement table. If not at the front of the first outlet portion33, the main control CPU80controls the driving motor34to locate the ball receiving part23in which the ball11is received at the front of the first outlet portion33in order to launch the ball11(see S6to8inFIG. 16).

Next, the rotation driving mechanism and the rotating operation of the rotatable portion20will be described with reference toFIGS. 4,9.

As shown inFIG. 4, the driving motor34is fixed on the bottom panel21A of the rim21. The driving motor34is a stepping motor capable of rotating in a step unit by feeding a pulse signal thereto. The number and durations of the pulse signals fed to the driving motor34determine a rotation angle and a rotation speed of the driving motor34. The driving motor34is connected to the main control CPU80. The main control CPU80controls the driving motor34according to a program stored in the ROM81(seeFIGS. 13,14). When the main control CPU80stops feeding the pulse signal to the driving motor34, the driving motor34holds the rotation angle thereof.

The driving motor34is connected to the rotatable portion20via a driven shaft46and a driven roller47. The driven shaft46has one end connected to the driving motor34and the other end connected to the driven roller47. The driven shaft46rotates at the same rotation angle and rotation speed as those of the driving motor34. The driven roller47has an outer surface abutting on a side surface20A of the rotatable portion20. When the main control CPU80drives the driving motor34, the driving motor34rotates the driven roller47via the driven shaft46to further rotate the rotatable portion20with respect to the center fixed portion22. The driven roller47is received in a roller case48having a substantial U-letter shape. The roller case48is biased toward the side surface20A of the rotatable portion20by a biasing member49. The biasing member49always presses the driven roller47on the side surface20A via the roller case48at a proper pressure, which prevents the driven roller47from rotating in overload or without abutting on the side surface20A.

As shown inFIGS. 4,9, an inner extending wall51of the rotatable portion20is rotatably connected to an outer extending wall50of the center fixed portion22via the cross ball bearing26. The cross ball bearing26has a substantial ring shape and a substantial square section. The cross ball bearing26has a plurality of bearings52respectively mounted to somewhere between thirty to forty parts on four side surfaces thereof. The bearings26abut the inner extending wall51and the outer extending wall50, so that the rotatable portion20is rotatably supported by the center fixed portion22.

In this configuration, the rotatable portion20rotates at a certain speed and by a certain angle with respect to the center fixed portion22, according to a rotation speed and a rotation angle of the driving motor34driven by the pulse signals. This allows the ball detecting sensors44to detect the ball receiving part23in which the ball11is received, and also allows the first outlet portion33to launch the ball11received in the ball receiving part23.

Next, the configurations of the control portion6and the image display device7with reference toFIGS. 1,10.

As shown inFIG. 1, the control portion6is arranged on the right side of the image display device7and includes buttons to be pressed by a player. More specifically, the control portion6has a BET determination button62, a PAYOUT button63and a HELP button64in this order from the left side thereof.

When a player determines a bet after carrying out a bet operation in the image display device7, the player presses the BET determination button62. Then, if one numeral on which the player has bet becomes a winning number, the number of credits corresponding to the number of bet game media is added to the number of credits which the player possesses at this time. The bet operation will be described later.

When a player finishes playing a roulette game, the player presses the PAYOUT button63. If the PAYOUT button63is pressed, one or more game media corresponding to the number of credits which the player possesses at this time are paid out from the medal payout slot8. Normally, one game medium corresponds to one credit.

When a player does not know how he/she plays a roulette game, the player presses the HELP button64. If the HELP button64is pressed, the image display device7displays a help screen including various types of operation information thereon.

The image display device7is a liquid crystal display with a touch panel53mounted on a front surface of the liquid crystal display (seeFIG. 12). When a player presses via the touch panel53an icon displayed on the liquid crystal display with his/her finger, the icon is selected.

As shown inFIG. 10, the image display device7displays a BET screen61thereon during a roulette game. A player can bet one or more virtual betting chips on one or more desired numerals by means of own one or more credits when operating the BET screen61. The BET screen61includes a table type betting board60, a result history display part65, unit BET buttons66, a payout result display part67, a credit number display part68and a BET timer graph69therein.

On the table type betting board60, numerals “0”, “00” and “1” to “36” are arranged in a grid. Also, graphic characters indicating “EVEN”, “ODD”, “black”, “red”, “1 to 18”, “19 to 36”, “1ST 12”, “2nd 12”, “3rd 12” and “2 to 1” are arranged on the table type betting board60in a grid.

Below the table type betting board60, the result history display part65, the unit BET buttons66, the payout result display part67and the credit number display part68are arranged on the BET screen61. Above the table type betting board60, the BET timer graph69is arranged on the BET screen61.

On the result history display part65, a list of up to sixteen winning numbers is displayed. More specifically, when one roulette game finishes, one winning number selected in the one roulette game is added from the top of the list and the oldest winning number is deleted from the bottom of the list. It is noted that one roulette game means a sequence of events from betting on one or more desired numerals in the satellite4to paying out one or more credits according to one winning number selected in this roulette game.

When a player bets on one or more desired numerals, the player operates the unit BET buttons66. The unit BET buttons66includes a 1 BET button66A, a 5 BET button66B, a 10 BET button66C and a 100 BET button66D. First, a player directly presses with his/her finger a BET area of the table type betting board60including a numeral on which the player desires to bet, via the touch panel53. This causes a cursor70to move on the BET area. Then, when the player presses the 1 BET button66A, the virtual betting chip is bet by one chip (the number of bets increases in an order of “1”→“2”→“3” . . . each time the 1 BET button66A is pressed with a finger). When the player presses the 5 BET button66B, the virtual betting chips are bet by five chips (the number of bets increases in an order of “5”→“10”→“15” . . . each time the 5 BET button66B is pressed with a finger). When the player presses the 10 BET button66C, the virtual betting chips are bet by ten chips (the number of bets increases in an order of “10”→“20”→“30” . . . each time the 10 BET button66C is pressed with a finger). When the player presses the 100 BET button66D, the virtual betting chips are bet by one hundred chips (the number of bets increases in an order of “100”→“200”→“300” . . . each time the 100 BET button66D is pressed with a finger). Accordingly, a player can bet a large amount of vertical betting chips with simplified operation.

On the payout result display part67, the number of virtual betting chips bet by a player and the number of credits paid out in a previous roulette game are displayed. At this time, the number of paid out credits minus the number of bet credits is equal to the number of credits which the player has newly obtained in the previous roulette game.

On the credit number display part68, the number of credits which a player currently possesses is displayed. The number of credits decreases according to the number of virtual betting chips when a player bets the virtual betting chips. The number of credits increases according to the number of paid out credits when a numeral on which a player has bet becomes a winning number. If the number of credits is equal to 0, the roulette game finishes.

The BET timer graph69is a graph that shows a remaining time before the roulette gaming machine1closes acceptance of the player's bet. In the BET timer graph69, a red bar gradually extends toward the right end of the BET timer graph69when one roulette game starts. If the red bar reaches the right end of the BET timer graph69, the roulette gaming machine1closes the acceptance of the player's bet. At five seconds before the red bar reaches the right end of the BET timer graph69, the ball11received in the ball receiving part23is launched by means of the first outlet portion33.

On the cursor70placed on the BET area where a player has selected, a chip mark71is displayed to indicate the BET area and the number of virtual betting chips. A numeral displayed on the chip mark71indicates the number of virtual betting chips bet by the player. For example, as shown inFIG. 10, the chip mark71of “7” placed on the BET area “18” indicates that the player has bet seven virtual betting chips on one numeral “18”. A method of betting on only one numeral is called a straight up betting method. The chip mark71of “1” placed on an intersecting point of the BET areas “5”, “6”, “8” and “9” indicates that the player has bet one virtual betting chip on four numerals “5”, “6”, “8” and “9” simultaneously. A method of betting on the four numerals is called a corner betting method.

Examples of other betting method include the following methods: a split betting method of betting on two numerals by placing the chip mark71on a line between the two numerals; a street betting method of betting on three numerals (e.g. “13”, “14” and “15”) by placing the chip mark71on a vertical line ofFIG. 10; a five betting method of betting on five numerals “0”, “00”, “1”, “2” and “3” by placing the chip mark71on a vertical line between “00” and “3”; a line betting method of betting on six numerals (e.g. “13”, “14”, “15”, “16”, “17” and “18”) by placing the chip mark71on a vertical line ofFIG. 10; a column betting method of betting on twelve numerals by placing the chip mark71on the graphic character “2 to 1” corresponding to the twelve numerals; a dozen betting method of betting on twelve numerals by placing the chip mark71on the graphic character “1st 12”, “2nd 12” or “3rd 12” corresponding to the twelve numerals; and another betting method of betting on eighteen numerals according to a color (red or black) of the number indication part24, odd or even numbers, or “1 to 18” or “19 to 36” by placing the chip mark71on each of six graphic characters arranged on the bottom of the table type betting board60.

When a player makes a bet by using the BET screen61, the player specifies a desired BET area on the BET screen61and then presses it with his/her finger directly. The cursor70thereby moves on the desired BET area. Then, the player operates the unit BET buttons66, the virtual betting chips corresponding to the respective units are bet on the desired BET area. For example, when the player presses the 10 BET button66C four times, the 5 BET button66B one time and the 1 BET button66A three times, forty-eight virtual betting chips can be bet.

Next, a control system of the roulette gaming machine1will be described with reference toFIG. 11.

As shown inFIG. 11, the control system of the roulette gaming machine1comprises the roulette device2, the plurality of satellites4, a motor driving circuit55, the electronic display unit77, a main controller83, a timer84, a random number generating circuit85and a random number sampling circuit86.

The main controller83comprises the main control CPU80, the ROM81and a RAM82. The roulette device2, the satellites4, the motor driving circuit55, the electronic display unit77, the ROM81, the RAM82, the timer84, the random number generating circuit85and the random number sampling circuit86are connected to the main control CPU80. The main control CPU80executes various processes according to various input signals from the respective satellites4and the data and program stored in the ROM81or the RAM82. The main control CPU80transmits order signals to the respective satellites4according to the result of processes. When the satellite4receives the order signal, a roulette game proceeds in the satellites4.

The roulette device2comprises the first valve17, the second valve18, the driving motor34, the ball detecting sensor44, the identification sensor57and the rotation sensor58. The first valve17, the second valve18, the ball detecting sensor44, the identification sensor57and the rotation sensor58are connected to the main control CPU80. Also, the driving motor34is connected to the main control CPU80via the motor driving circuit55.

The main control CPU80transmits various order signals to the roulette device2according to the result of processes. When the roulette device2receives a motor driving order signal, the driving motor34is driven to launch the ball11and then cause the launched ball11to roll. More specifically, when the main control CPU80outputs the motor driving order signal into the motor driving circuit55, the motor driving circuit55generates pulse signals to output them into the driving motor34. If the driving motor34receives the pulse signals, the driving motor34is driven to rotate at a certain rotation speed, in a certain rotation direction and during a certain period, according to the received pulse signals. Thereby, the rotatable portion20rotates with respect to the rim21and the center fixed portion22, at the certain rotation speed, in the certain rotation direction and during the certain period, according to a control program for the driving motor34stored in the ROM81.

When the roulette device2receives sensor action order signals, the ball detecting sensors44, the identification sensor57and the rotation sensor58are controlled to obtain various types of associated information and then output them to the main controller83. Thereby, the main control CPU80can identify one numerical (winning number) corresponding to the ball receiving part23in which the ball11is received. Also, the main control CPU80can determine whether or not the ball receiving part23in which the ball11is received is located at the front of the first outlet portion33. Further, when the roulette device2receives valve action order signals, the first valve17and the second valve18are opened or closed to adjust air pressure within the air tubes15,16. If the first valve17is opened, air compressed by the compressor14is discharged from the first outlet33. If the second valve18is opened, air compressed by the compressor14is discharged from the second outlets36.

The ROM81consists of a semiconductor memory and permanently stores therein the following data and programs: a program for implementing basic functions of the roulette gaming machine1; a program for controlling elements (e.g. the first valve17, the second valve18, the driving motor34, the ball detecting sensor44, the identification sensor57and the rotation sensor58) in the roulette device2; a rotation period lottery table99employed when one rotation pattern of the rotatable portion20(drive control pattern for the driving motor34) is selected among a plurality of rotation patterns (seeFIG. 15); odds (the number of credits paid out per one virtual betting chip) for a typical roulette game; a program for controlling the respective satellites4; and the member arrangement table.

The RAM82temporarily stores therein the following data and programs: bet information about the virtual betting chips supplied from the respective satellites4; a winning number identified by the main control CPU80; and various data on results of processes executed by the main control CPU80.

The random number generating circuit85sequentially generates random numbers within a constant range according to an order of the main control CPU80. The random number sampling circuit86samples one random number among the generated random numbers in a certain sampling period and then inputs the sampled random number into the main control CPU80according to an order of the main control CPU80. The sampled random number is employed to select one rotation pattern of the rotatable portion20among the plurality of rotation patterns, with reference to the rotation period lottery table99.

The electronic display unit77controls emission of an emission means such as a light emitting diode (LED) to produce electrical spectaculars or cause the jackpot value display78to display the jackpot value. The timer84outputs time information into the main control CPU80. The main control CPU80controls the first valve17, the second valve18and the driving motor34according to the time information.

Next, a control system of the satellite4will be described with reference toFIG. 12.

As shown inFIG. 12, the control system of the satellite4comprises the control portion6, the image display device7, the speaker9, a satellite controller90, the hopper94, a liquid crystal driving circuit95, a sound output circuit96and the medal sensor97. The satellite controller90comprises a satellite control CPU91, a ROM92and a RAM93. The control portion6, the image display device7, the ROM92, the RAM93, the hopper94, the liquid crystal driving circuit95, the medal sensor97are connected to the satellite control CPU91. Also, the speaker9is connected to the satellite control CPU91via the sound output circuit96.

The ROM92consists of a semiconductor memory and permanently stores therein the following data and programs: a program for implementing basic functions of the satellite4; and a program and table for controlling elements in the satellite4. The RAM93temporarily stores therein the following data and programs: various data on results of processes executed by the satellite control CPU91; the number of credits which a player currently possesses; and bet information about the virtual betting chips bet by a player.

In the control portion6, the BET determination button62, the PAYOUT button63and the HELP button64are connected to the satellite control CPU91. When the BET determination button62is pressed, the satellite control CPU91receives a determination signal from the control portion6to execute various processes according to the programs and data stored in the ROM92and/or the RAM93. Then, the satellite control CPU91outputs data on results of the processes into the main control CPU80. When the PAYOUT button63is pressed, the satellite control CPU91receives a payout order signal from the control portion6and controls the hopper94to pay out from the medal payout slot8one or more game media corresponding to the number of credits which a player currently possesses. When the HELP button64is pressed, the satellite control CPU91receives a help order signal from the control portion6and control the image display device7by means of the liquid crystal driving circuit95to display the help screen on the image display device7. Further, when a winning number is determined, the satellite control CPU91receives an update order signal from the main control CPU80and control the image display device7by means of the liquid crystal driving circuit95to update contents displayed on the BET screen61.

The liquid crystal driving circuit95comprises a program ROM, an image ROM, an image control CPU, a work RAM, a video display processor (VDP) and a video RAM. The program ROM stores therein an image control program and various selection tables regarding a display of the image display device7. The image ROM stores therein dot data employed to form an image to be displayed on the image display device7. The image control CPU determines an image to be displayed on the image display device7on the basis of the dot data, according to a parameter set in the satellite control CPU91and the image control program. The work RAM is temporarily employed when the image control CPU executes the image control program. The VDP is employed to form an image according to display contents determined by the image control CPU and then output it into the image display device7. The video RAM is temporarily employed when the VDP forms the image.

The touch panel53is mounted on the front surface of the liquid crystal display in the image display device7. When a player has carried out an operation of the touch panel53such as a selection of the BET area and an operation of the unit BET buttons66, bet information about virtual betting chips bet by the player is supplied to the satellite control CPU91. If the satellite control CPU91receives the bet information, the satellite control CPU91stores the bet information (e.g. one or more BET areas specified by the player and the number of the virtual betting chips) on the RAM93. Further, the satellite control CPU91supplies the bet information to the main control CPU80and then stores it on a bet information memory area in the RAM82.

The satellite4outputs effective sounds via the speakers9according to an output signal from the sound output circuit96. The medal sensor97detects the number of game media inserted from the medal insertion slot5and outputs it into the satellite control CPU91. The satellite control CPU91increases the number of credits stored in the RAM93according to the number of inserted game media.

Next, an open-and-close timing of the first valve17and the second valve18and a drive timing of the driving motor34will be described with reference toFIG. 13.

As shown inFIG. 13, when one roulette game starts, the one roulette game proceeds with a bet period for receiving the player's bet in the satellite4. At ten seconds before the bet period is over, if the main control CPU80determines that the ball receiving part23receiving the ball11therein is not located at the front of the first outlet portion33according to a previous winning number and a detection result of the identification sensor57, the main control CPU80drives the driving motor34at a first rotation speed and in a certain rotation direction, to rotate the rotatable portion20with respect to the center fixed portion22at a certain rotation speed (e.g. 4 rpm) until the ball receiving part23is located at the front of the first outlet portion33. Then, at five seconds before the bet period is over, the main control CPU80simultaneously opens the first valve17during a certain period (2 seconds in the present exemplary embodiment) and the second valve18during a certain period (20 seconds in the present exemplary embodiment). Thereby, the ball11is launched from the ball receiving part23toward the bank passage29and then rolls on the bank passage29in a clockwise direction of the bank passage29.

When the certain period regarding the first valve17is over, the main control CPU80drives the driving motor34to rotate the rotatable portion20with respect to the center fixed portion22, during a first step period. The rotation speeds of the driving motor34and the rotatable portion20linearly increase until they reach a second rotation speed and a certain rotation speed (e.g. 5.005 rpm). Then, when the first step period is over, the main control CPU80drives the driving motor34to rotate the rotatable portion20with respect to the center fixed portion22, during a second step period. The rotation speeds of the driving motor34and the rotatable portion20linearly increase until they reach a third rotation speed and a certain rotation speed (e.g. 16.683 rpm). Here, it is noted that parts of the first and second step periods are varied every one roulette game, according to one random number sampled among the generated random numbers (seeFIG. 14).

When the certain period regarding the second valve18is over, the main control CPU80closes the second valve18to stop discharging the compressed air from the second outlet portions36. Thereby, the ball11gradually decelerates because air-flow disappears from the bank passage29. The ball11rolls down the first slope surface28B of the rim21in time to reach the rotating rotatable portion20. When the ball11enters the rotating rotatable portion20, the ball11rolls on the number indication part24and then is received into one of the ball receiving parts23. At a few seconds after the second valve18is closed, the main control CPU80linearly decreases the rotation speed of the driving motor34to slow the rotation speed of the rotatable portion20. While the rotatable portion20slowly rotates, the main control CPU80drives the ball detecting sensor44, the identification sensor57and the rotation sensor58to determine a winning number on the basis of data from these sensors and the member arrangement table stored in the ROM81. Then, the main control CPU80transmits the update order signal to the satellite control CPU91and the one roulette game finishes. If next one roulette game continuously starts, the above processes are carried out again.

Next, a rotation form of the rotatable portion20and a drive control of the driving motor34between the time when the ball11is launched and the time when the ball11rolls down will be described, with reference toFIG. 14.

As shown inFIG. 14, a rotation term of the rotatable portion20between the time when the ball11is launched and the time when the ball11rolls down consists of seven periods.

In a first period T1between the time when the ball11is launched and the time when the rotatable portion20starts to rotate, the main control CPU80continues to stop driving the driving motor34so that the rotation speed of the rotatable portion20is equal to 0 rpm.

In a second period T2between the time when the rotatable portion20starts to rotate and the time when the rotation speed of the rotatable portion20reaches 5.005 rpm, the main control CPU80drives the driving motor34so that the rotation speed of the rotatable portion20linearly increases from 0 rpm to 5.005 rpm.

In a third period T3between the time when the rotation speed of the rotatable portion20is equal to 5.005 rpm and the time when the main control CPU80closes the acceptance of the player's bet, the main control CPU80drives the driving motor34so that the rotatable portion20maintains the rotation speed at 5.005 rpm.

In a fourth period T4between the time when the main control CPU80closes the acceptance of the player's bet and the time when the rotation speed of the rotatable portion20starts to increase again, the main control CPU80drives the driving motor34so that the rotatable portion20maintains the rotation speed at 5.005 rpm.

In a fifth period T5between the time when the rotation speed of the rotatable portion20starts to increase again and the time when it reaches 16.683 rpm, the main control CPU80drives the driving motor34so that the rotation speed of the rotatable portion20linearly increases from 5.005 rpm to 16.683 rpm.

In a sixth period T6between the time when the rotation speed of the rotatable portion20is equal to 16.683 rpm and the time when the main control CPU80closes the second valve18, the main control CPU80drives the driving motor34so that the rotatable portion20maintains the rotation speed at 16.683 rpm.

In a seventh period T7between the time when the main control CPU80closes the second valve18and the time when the ball11will roll down, the main control CPU80drives the driving motor34so that the rotatable portion20maintains the rotation speed at 16.683 rpm.

The first step period consists of the second to fourth periods T2, T3, T4. The second step period consists of the fifth to seventh periods T5, T6, T7. Time lengths of the first to third, fifth and sixth periods T1, T2, T3, T5, T7are fixed. On the other hand, time lengths of the fourth and sixth periods T4, T6are varied every one roulette game, according to one random number sampled among the generated random numbers, the rotation period lottery table99, the member arrangement table, and a positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and one numeral (previous winning number) assigned to the ball receiving part23in which the ball11is received.

Next, a process for determining time lengths of the fourth and sixth periods T4, T6will be described with reference toFIG. 15.

As shown inFIG. 15, combinations of time lengths of the fourth and sixth periods T4, T6are previously set to thirty-eight patterns in the rotation period lottery table99. The main control CPU80selects one pattern among the thirty-eight patterns on the basis of one random number sampled among the random numbers sequentially generated within the range of “0” to “37” by the random number sampling circuit86. For example, if the sampled one random number is equal to “32”, the main control CPU80selects one combination of the time length “0.776 sec” of the fourth period T4and the time length “4.500 sec” of the sixth period T6. If the sampled one random number is equal to “7”, the main control CPU80selects one combination of the time length “4.156 sec” of the fourth period T4and the time length “1.120 sec” of the sixth period T6.

In the rotation period lottery table99, although the total time length of the fourth and sixth periods T4, T6is fixed to “5.276 sec”, a rotation number per 5.276 sec of the rotatable portion20increases from “n” to “n+ 1/38” (0<n) in proportion as the random number increases from “m” to “m+1” (0≦m≦36). More specifically, the rotatable portion20rotates by extra one ball receiving part23in proportion as the random number increases from “m” to “m+1”.

The main control CPU80compensates the sampled random number, on the basis of the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and one numeral (previous winning number) assigned to the ball receiving part23in which the ball11is received. More specifically, the main control CPU80first identifies one numeral assigned to the ball receiving part23opposed to the identification sensor57, by means of the identification sensor57. Next, the main control CPU80calculates the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and the previous winning number, with reference to the identified one numeral and the member arrangement table. It is noted that a position a relation between the identification sensor57and the first outlet portion33has been defined in the member arrangement table. When the main control CPU80identifies the previous winning number as 1-th numeral (0≦1≦38) from one numeral assigned to the ball receiving part23opposed to the first outlet portion33in an anticlockwise direction of the number identification part24, the main control CPU80adds “1” to the sampled random number and then identifies the added random number as a compensation random number. If the added random number is more than “37”, the main control CPU80subtracts “38” from the added random number and then identifies the subtracted random number as a compensation random number. Then, the main control CPU80sets values corresponding to the compensation random number in the rotation period lottery table99to time lengths of the fourth and sixth periods T4, T6(seeFIG. 18). Therefore, the rotatable portion20rotates by extra “1” ball receiving part(s)23in an anticlockwise direction thereof during the fourth and sixth periods T4, T6.

In the roulette gaming machine1, when the ball11is launched, the ball receiving part23in which the ball11is received is located at the front of the first outlet portion33. The main control CPU80however carries out the above-described compensation according to the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and one numeral (previous winning number) assigned to the ball receiving part23in which the ball11is received. Therefore, in a case where the random number generating circuit85is a pseudo random number generating circuit, even if skilled players obtain the previous winning number, the tendency for random numbers to be generated by the random number generating circuit85, and the fourth and sixth periods T4, T6corresponding to each random number in each roulette game, they can not roughly predict a next winning number because they need to additionally know the arrangement of the rotatable portion20at the time of stopping the rotation of the rotatable portion20after the ball11is received in one of the ball receiving parts23in the previous roulette game.

As a result of the compensation, the arrangement of the rotatable portion20at the time of stopping the rotation of the rotatable portion20depends on randomness in the current roulette game and chaos in the previous roulette game. It is noted that the randomness is caused when the random number generating circuit85sequentially generates random numbers and the chaos is caused when the ball11rolls on the roulette board12. The tendency for random numbers is therefore disturbed by the chaos caused in the previous roulette game. On the other hand, in the conventional roulette gaming machine, since the compensation is not carried out, the arrangement of the rotatable portion at the time stopping the rotation of the rotatable portion depends on only randomness caused when the random number generating circuit sequentially generates random numbers in the current roulette game. The tendency for random numbers therefore remains.

Next, a roulette game process program executed by the roulette gaming machine1will be described with reference toFIGS. 16,17.

In step S1, the main control CPU80determines whether or not a player has inserted one or more medals and/or bills. When the player inserts one or more medals and/or bills into the medal insertion slot5in each satellite4, the medal sensor97detects the inserted medals and/or bills and then sends a detecting signal to the satellite control CPU91. The satellite control CPU91of the satellite4transmits a medal detecting signal to the main control CPU80of the roulette gaming machine1. Also, the satellite control CPU91stores in the RAM93the number of credits corresponding to the inserted one or more medals and/or bills. When the main control CPU80receives the medal detecting signal, the main control CPU80determines that the player has inserted one or more medals and/or bills. If the player has inserted one or more medals and/or bills, the process proceeds in step S2. If the player has not inserted one or more medals and/or bills, the process remains in step S1.

In step S2, a bet period when the main control CPU80receives a player's bet starts. When the bet period starts, the satellite control CPU91causes the image display device7to display the BET screen61thereon (seeFIG. 10). The bet period is shown by the BET timer graph69. When the bet period starts, the satellite control CPU91also causes the red bar in the BET timer graph69to gradually extend toward the right side of the BET timer graph69. If the red bar reaches the right side of the BET timer graph69, the bet period is over. During the bet period, the player can operate the touch panel53to bet one or more virtual betting chips on one or more desired numerals. It is noted that other players (up to twelve players in the present exemplary embodiment) can participate this roulette game during the bet period.

In step S3, if there is a winning number in a previous roulette game on a winning number memory area of the RAM82, the main control CPU80reads the winning number from the RAM82. In step S4, the main control CPU80carries out a drive control pattern lottery process for selecting one driving control pattern for the driving motor34by means of a random number sampled by the random number sampling circuit86and the rotation period lottery table99(seeFIG. 18).

In step S5, the main control CPU80determines whether or not it reaches ten seconds before the bet period is over. If it reaches ten seconds before the bet period is over, the process proceeds to step S6. If it does not reach ten seconds before the bet period is over, the process remains in step S5. In step S6, the main control CPU80determines whether or not the ball receiving part23receiving the ball11therein is located at the front of the first outlet portion33according to the previous winning number and a detection result of the identification sensor57. If the ball receiving part23receiving the ball11therein is located at the front of the first outlet portion33, the process proceeds to step S9. If the ball receiving part23receiving the ball11therein is not located at the front of the first outlet portion33, the process proceeds to step S7.

In step S7, the main control CPU80drives the driving motor34at the first rotation speed and in a certain rotation direction, to rotate the rotatable portion20with respect to the center fixed portion22at a certain rotation speed (e.g. 4 rpm) until the ball receiving part23receiving the ball11therein is located at the front of the first outlet portion33. In step S8, when the ball receiving part23receiving the ball11therein is located at the front of the first outlet portion33, the main control CPU80stops driving the driving motor34.

For example, as shown inFIG. 19, it assumes that the ball receiving part23(opposed to the area of the number indication part24to which the numeral “29” is arranged) receiving the ball11therein is the twenty-seventh ball receiving part23with respect to the ball receiving part23opposed to the first outlet portion33, in the clockwise direction of the number indication part24. In this case, the main control CPU80drives the driving motor34to rotate the rotatable portion20in the anticlockwise direction and at the certain rotation angle corresponding to twenty-seven ball receiving parts23.

In step S9, the main control CPU80turns on the compressor14to cause the compressor14to compress the surrounding air. In step S10, the main control CPU80determines whether or not it reaches five seconds before the bet period is over. If it reaches five seconds before the bet period is over, the process proceeds to step S11. If it does not reach five seconds before the bet period is over, the process remains in step S10.

In step S11, the main control CPU80simultaneously opens the first valve17during the certain period t1(2 seconds in the present exemplary embodiment) and the second valve18during the certain period t2(20 seconds in the present exemplary embodiment). Thereby, the ball11is launched from the ball receiving part23toward the bank passage29in a direction of an arrow72shown inFIG. 20and then rolls on the bank passage29in a direction of an arrow73shown inFIG. 21. In step S12, the main control CPU80determines whether or not the certain period t1regarding the first valve17is over, by using the timer84. If the certain period t1is over, the process proceeds to step S13. If the certain period t1is not over, the process remains in step S12.

In step S13, the main control CPU80closes the first valve17. In step S14, the main control CPU80drives the driving motor34to rotate the rotatable portion20with respect to the center fixed portion22during the first and second step periods, according to the one drive control pattern selected in the drive control pattern lottery process in step S4.

As shown inFIG. 21, when the main control CPU80opens the second valve18in step S11, the second valve18generates air-flow in the clockwise direction along the bank passage29by the compressed air discharged from the second outlet portions36. The traveling direction of the launched ball11is changed from the radial direction to the circumferential direction of the roulette board12by the air-flow, along a direction of an arrow74.

In step S15, the main control CPU80determines whether or not the bet period is over. If the bet period is over, the process proceeds to step S16. If the bet period is not over, the process remains in step S15. In step S16, the main control CPU80transmits a betting end signal to the satellite control CPU91of each satellite4and then receives bet information about virtual betting chips bet by the player from the satellite control CPU91of each satellite4. More specifically, if the satellite control CPU91receives the betting end signal, the satellite control CPU91causes the image display device7to display “BET PERIOD IS OVER” on the BET screen61and rejects the operations from the touch panel53. Then, the satellite control CPU91transmits the bet information to the main control CPU80and then stores the bet information on the bet information memory area in the RAM82.

In step S17, the main control CPU80determines whether or not the certain period t2regarding the second valve18is over, by using the timer84. If the certain period t2is over, the process proceeds to step S18. If the certain period t2is not over, the process remains in step S17. In step S18, the main control CPU80closes the second valve18. In step S19, the main control CPU80turns off the compressor14to cause the compressor14to stop compressing the surrounding air.

As shown inFIG. 22, when the main control CPU80closes the second valve18in step18, the air-flow disappears from the bank passage29. Thereby, the ball11gradually decelerates and then rolls down the first slope surface28B of the rim21in time to reach the rotating rotatable portion20(see a direction of an arrow75). When the ball11enters the rotating rotatable portion20, the ball11rolls on the number indication part24and then is received into one of the ball receiving parts23.

In step20, the main control CPU80determines a winning number by means of the ball detecting sensor44, the identification sensor57and the rotation sensor58. More specifically, at a few seconds after the second valve18is closed, the main control CPU80linearly decreases the rotation speed of the driving motor34to slow the rotation speed of the rotatable portion20. While the rotatable portion20slowly rotates, the main control CPU80drives the ball detecting sensor44, the identification sensor57and the rotation sensor58to determine the winning number on the basis of data from these sensors and the member arrangement table stored in the ROM81.

In step S21, the main control CPU80stops driving the driving motor34. In step S22, the main control CPU80determines whether or not the winning number is equal to one of the one or more desired numerals on which the player has bet in each satellite4, on the basis of the winning number determined in step S20and the bet information stored in the RAM82. If the winning number is equal to one of the one or more desired numerals, the process proceeds to step S23. If the winning number is not equal to one of the one or more desired numerals, the process proceeds to step S25.

In step S23, the main control CPU80carries out a dividend calculation process. In the dividend calculation process, the main control CPU80recognizes each satellite4in which the player has bet on the winning number and then calculates a dividend amount to be paid out for the each satellite4by means of odds (the number of credits per one virtual betting chip to be paid out) stored in a dividend credit memory area of the ROM81, with respect to the BET area, which includes the winning number, specified by the player.

In step S24, the main control CPU80transmits credit data corresponding to the calculated dividend amount to the satellite control CPU91of the each satellite4. If the satellite control CPU91receives the credit data, the satellite control CPU91carries out a payout process. In the payout process, the satellite control CPU91adds the number of credits corresponding to the calculated dividend amount to the number of credits, which the player possesses at this time, stored in the RAM93.

In step S25, the main control CPU80carries out an update process. In the update process, the main control CPU80transmits an update order signal to the satellite control CPU91of each satellite4. If the satellite control CPU91receives the update order signal, the satellite control CPU91updates contents displayed on the BET screen61and then finish one roulette game.

In step S26, the main control CPU80determines whether or not the process finishes. More specifically, the main control CPU80determines whether or not all participating one or more satellites4transmit process end signals thereto. In each participating satellite4, if the PAYOUT button63is pressed, the satellite control CPU91paid out one or more game media corresponding to the number of credits which the player possesses at this time, from the medal payout slot8via the hopper94. Then, the satellite control CPU91transmits the process end signal to the main control CPU80. If the main control CPU80receives the process end signals from the all participating one or more satellites4, the main control CPU80rotates the rotatable portion20so that the ball receiving part23in which the ball11is received is located at the front of the first outlet portion33, and then finishes the process. If the main control CPU80does not receive the process end signals from the all participating one or more satellites4, the process proceeds to step S2to carry out next one roulette game.

Next, the drive control pattern lottery process to be carried out in step S4will be described with reference toFIG. 18.

In step S31, the main control CPU80causes the random number sampling circuit86to sample one random number among the random numbers sequentially generated within the range of “0” to “37”, in a certain sampling period. In step S32, the main control CPU80selects one combination of time lengths of the fourth and sixth periods T4, T6among the thirty-eight combinations on the basis of the sampled one random number and the rotation period lottery table99. For example, if the sampled one random number is equal to “32”, the main control CPU80selects one combination of the time length “0.776 sec” of the fourth period T4and the time length “4.500 sec” of the sixth period T6. If the sampled one random number is equal to “7”, the main control CPU80selects one combination of the time length “4.156 sec” of the fourth period T4and the time length “1.120 sec” of the sixth period T6.

In step S33, the main control CPU80determines whether or not the winning number in the previous roulette game has been read from the winning number memory area of the RAM82in step S3. If the winning number in the previous roulette game is read, the process proceeds to step S34. If the winning number in the previous roulette game is not read, the process proceeds to step S5. In step S34, the main control CPU80compensates the sampled one random number, with reference to the member arrangement table and the winning number in the previous roulette game. The main control CPU80first identifies one numeral assigned to the ball receiving part23opposed to the identification sensor57, by means of the identification sensor57. Next, the main control CPU80calculates the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and the previous winning number, with reference to the identified one numeral and the member arrangement table. When the main control CPU80identifies the previous winning number as 1-th numeral (0≦1≦38) from one numeral assigned to the ball receiving part23opposed to the first outlet portion33in the anticlockwise direction of the number identification part24, the main control CPU80adds “1” to the sampled random number and then identifies the added random number as a compensation random number. If the added random number is more than “37”, the main control CPU80subtracts “38” from the added random number and then identifies the subtracted random number as a compensation random number. Then, the main control CPU80sets values corresponding to the compensation random number in the rotation period lottery table99to time lengths of the fourth and sixth periods T4, T6. Here, it is noted that the identified positional relation is employed in step S6. When the values are set, the process proceeds to step S5.

Next, advantageous features of the roulette gaming machine1will be described hereinafter.

In the roulette gaming machine1, time lengths of the fourth and sixth periods T4, T6are varied in each roulette game according to the compensation random number and the rotation period lottery table99. More specifically, one random number is sampled among the random numbers sequentially generated within the range of “0” to “37”. Then, the sampled random number is compensated according to the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and the previous number. If the main control CPU80identifies the previous winning number as 1-th numeral (0≦1≦38) from the one numeral in the anticlockwise direction of the rotatable portion20, the main control CPU80adds “1” to the sampled random number. The rotatable portion20rotates by extra “1” ball receiving part(s)23in the anticlockwise direction thereof during the fourth and sixth periods T4, T6. Therefore, in a case where the random number generating circuit85is a pseudo random number generating circuit, even if skilled players obtain the previous winning number, the tendency for random numbers to be generated by the random number generating circuit85, and the fourth and sixth periods T4, T6corresponding to each random number in each roulette game, they can not roughly predict a next winning number because they need to additionally know the arrangement of the rotatable portion20after the ball11is received in one of the ball receiving parts23in the previous roulette game.

As a result of the compensation, the arrangement of the rotatable portion20at the time of stopping the rotation of the rotatable portion20depends on randomness in the current roulette game and chaos in the previous roulette game. It is noted that the randomness is caused when the random number generating circuit85sequentially generates random numbers and the chaos is caused when the ball11rolls on the roulette board12. The tendency for random numbers is therefore disturbed by the chaos caused in the previous roulette game. On the other hand, in the conventional roulette gaming machine, since the compensation is not carried out, the arrangement of the rotatable portion at the time stopping the rotation of the rotatable portion depends on only randomness caused when the random number generating circuit sequentially generates random numbers in the current roulette. The tendency for random numbers therefore remains.

Since the total time length of the fourth and sixth periods T4, T6is fixed, the variation of the drive control pattern does not influence the total control of the roulette gaming machine1.

In the roulette gaming machine1, the main control CPU80rotates the rotatable portion20so that the ball receiving part23in which the ball11is received is located at the front of the first outlet portion33when the roulette game process is finished. Therefore, the arrangement of the rotatable portion20is reset at the time of finishing the roulette game process.

In the roulette gaming machine1, the ball11can be launched from one of the ball receiving parts23and received into one of the ball receiving parts23by adjusting air pressure to be discharged from the first outlet potion33and the second outlet portions36. Therefore, the roulette gaming machine1needs not complicate mechanisms for launching the ball11from one of the ball receiving parts23and collecting the ball11received in one of the ball receiving parts23because the ball11is not collected from the roulette board12. As a result, this can facilite the maintenance work of the roulette gaming machine1and reduce the cost of the roulette gaming machine1.

In the roulette gaming machine1, a collecting device for the ball11and a launching device for the ball11are not mounted. Therefore, the value of the depth L of the ball receiving part23with respect to the bottom surface of the ball receiving part23is smaller than the value of the diameter D of the ball11. Thereby, the height h and the oblique angle α of the roulette board12can be smaller and larger than those of the conventional roulette board, respectively (seeFIG. 5). As a result, this allows participating players to easily identify the ball11received in the ball receiving part23from every angle, during a roulette game.

In the roulette gaming machine1, the oblique angle α of the first slope surface28B is equal to that of the second slope surface28A. Thereby, the ball11is launched and smoothly rolls toward the bank passage29on the whole slope surface28.

In the roulette gaming machine1, the rotatable portion20is only rotated with respect to the center fixed portion22. This reduces the load of the driving motor34.

In the roulette gaming machine1, the bank passage29has the upper wall31. This prevents the rolling ball11from getting out of the bank passage29.

Next, modified examples of the present exemplary embodiment will be described hereinafter.

The time lengths of various periods may be varied instead of varying those of the fourth and sixth periods, under the condition that the total time length of the first to seventh periods is fixed.

The ball11may be launched by using a physical contact means such as a solenoid, instead of the compressed air from the first outlet portion33.

The air pass hole35may be formed into another shape instead of the circular shape.

The roulette device2may have a sub-control CPU connected to the ball detecting sensor44, the identification sensor57and the rotation sensor58and a ROM storing the member arrangement table therein, in order to determine the winning number and the positional relation between one numeral assigned to the ball receiving part23opposed to the first outlet portion33and the previous winning number.

The arrangement of the rotatable portion20may be not reset at the time of finishing the roulette game process.

The random number generating circuit85may generate random numbers depending on the arrangement of the rotatable portion20at the time of stopping the rotation of the rotatable portion20after the ball11is received in one of the ball receiving parts23in the previous roulette game. This more surely prevents skilled players from roughly predicting a next winning number.

It is noted that, besides those already mentioned above, many modifications and variations of the present exemplary embodiments may be made without departing from the novel and advantageous features of the present invention. Accordingly, all such modifications and variations are intended to be included within the scope of the appended claims.