US Patent 7674175 Video slot machine

A video slot machine is disclosed in which a plurality of reel images comprising at least two types of arranged symbols are displayed on a monitor. The video slot machine includes a game controller configured to control a game including a unit game in response to a BET operation; a display controller configured to control the monitor such that the symbols of the reel images are successively changed and then stopped for display during the unit game; a change time determination unit configured to determine whether or not it is time to change the reel images; and a reel image changing unit configured to change at least one of the reel images to a different reel image having a different symbol arrangement when the change timing determination unit determines that it is time to change the reel images.