Patent ID: 7789746

Claim:
A roulette gaming machine comprising: a roulette board; a ball for rolling on the roulette board; a rotatable portion having 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, the plurality of marks being 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 random number generating circuit configured to generate a pseudo random number; a selecting unit configured to select one drive control pattern among a plurality of drive control patterns for the driving unit according to the pseudo random number generated by the random number generating circuit; a ball launching unit being opposed to at least one of the ball receiving parts and configured to launch the ball received in the at least one of the ball receiving parts; and a rotation period variation control unit configured to vary a plurality of constant speed rotation periods for rotating the rotatable portion at a plurality of rotation speeds different from each other according to the one drive control pattern after the rotatable portion stops rotating in a previous roulette game and before the ball launching unit launches the ball received in the at least one of the ball receiving parts in a current roulette game, and then control the driving unit according to the varied plurality of constant speed rotation periods and the plurality of rotation speeds, wherein when a ball receiving part in which the ball is received in the previous roulette game is located apart from a ball receiving part opposed to the ball launching unit by n ball receiving parts (0≦n) in the certain direction, the rotation period variation control unit compensates the varied plurality of constant speed rotation periods without changing a total period of the varied plurality of constant speed rotation periods, and then controls the driving unit such that the rotatable portion rotates by extra n ball receiving parts in the certain direction during the total period after the ball receiving part in which the ball is received is opposed to the ball launching unit in the current roulette game.