PATENT ABSTRACT
To provide a gaming machine which can carry out a lizhi effect rich in impact without giving a feeling of boredom. 
     A gaming machine includes: a first display device which displays a plurality of symbols which can be variably displayed and stop displayed; a second display device which, being provided in front of the first display device, can display an image and can be switched to a transmissive condition or a non-transmissive condition; and a controller which controls the first display device and the second display device, the controller, in a case in which a combination of a plurality of symbols reaches a condition in which it lacks one symbol of a prescribed combination, putting at least a portion in front of symbols other than a last stop displayed symbol into the non-transmissive condition.

PATENT DESCRIPTION
RELATED APPLICATION 
     This application claims the priority of Japanese Patent Application No. 2006-190851 filed on Jul. 11, 2006, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a gaming machine which carries out a game using a token such as a coin, and a game control method according to the gaming machine. 
     2. Related Art 
     A slot machine, in which reels, on a peripheral surface of each of which is depicted a symbol column with a plurality of symbols, are rotated and then stopped, and a game result is determined according to a combination of symbols displayed, that is, a slot machine equipped with mechanical reels is divided roughly into a so-called pachi-slot machine and a so-called casino machine. The pachi-slot machine and the casino machine differ in whether or not an operation of stopping the rotation of the reels is needed. That is, the pachi-slot machine including a number of stop buttons equal to that of the reels, the rotation of the reels stops in accordance with a player&#39;s depression operation of the stop buttons. Meanwhile, the casino machine, including no stop button, is configured in such a way that each reel stops automatically in a prescribed order. 
     To date, the pachi-slot machine and the casino machine each being provided with a liquid crystal display device or the like, in accordance with the rotation, stopping or the like of the reels, a variety of effects due to an image is carried out on the liquid crystal display device or the like. 
     In recent years, in the pachi-slot machine, the fact has prevailed that, a transparent liquid crystal panel being installed in front of the reels, an image is displayed in front of the reels. As this kind of pachi-slot machine, for example, a pachi-slot machine exists in which, in a case in which each reel is stop displayed in a transparent display area of the transparent liquid crystal panel, by determining a display priority among a plurality of image elements, such as spotlights (a partial transmissive condition) or rocks, based on a stop display mode of the reels, it is possible to carry out an effect display in multifarious ways (for example, refer to Japanese Unexamined Patent Publication No. 2005-52449). 
     In the pachi-slot machine described in Japanese Unexamined Patent Publication No. 2005-52449, in a case in which an effect carried out in a condition in which a combination of a plurality of symbols lacks one symbol of a prescribed combination (a so-called lizhi effect) is carried out, for example, when a bonus symbol “red 7” is stop displayed in each of two of three reels, and a lizhi occurs, the display priority of the spotlights being made higher than that of the image representing the rocks, the lizhi effect by the reels is preferentially carried out. 
     SUMMARY OF THE INVENTION 
     The invention has an object of providing a gaming machine which can carry out a lizhi effect rich in impact without giving a feeling of boredom, and a game control method. 
     In order to achieve the heretofore described object, the invention provides the following. 
     A gaming machine of the invention includes: a first display device which displays a plurality of symbols which can be variably displayed and stop displayed; a second display device which, being provided in front of the first display device, can display an image and can be switched to a transmissive condition or a non-transmissive condition; and a controller which controls the first display device and the second display device, the controller, in a case in which a combination of the plurality of symbols reaches a condition in which it lacks one symbol of a prescribed combination, by controlling the second display device, putting at least a portion in front of symbols other than a last stop displayed symbol into the non-transmissive condition. 
     According to the heretofore described configuration, in a case of the heretofore described condition, by at least a portion of the second display device taking on the non-transmissive condition, as the symbols other than the last stop displayed symbol are now in an invisible condition, it is not necessary to wait aimlessly until the symbols other than the last stop displayed symbol stop. Consequently, it being possible to increase the player&#39;s hope for and joy at a winning combination at a point at which an effect carried out in the condition in which the combination of the plurality of symbols lacks one symbol of the prescribed combination, that is, a lizhi effect, is carried out, it is possible as a result to make the lizhi effect rich in impact for the player. 
     In the invention, the “transmissive condition” refers to a condition in which a symbol is visible or easy to visually perceive from a front, and the “non-transmissive condition” refers to a condition in which the symbol is invisible or difficult to visually perceive from the front. That is, it being sufficient that a difference in symbol visibility occurs between the transmissive condition and the non-transmissive condition, the non-transmissive condition does not refer to a condition in which the symbol is literally invisible. Also, in the invention, “invisible”, being a concept including a condition of being invisible and a condition of being difficult to visually perceive, does not refer to a literally invisible condition. Also, the condition in which the combination of the plurality of symbols lacks one symbol of the prescribed combination will be referred to hereafter as a “lizhi”. 
     In the gaming machine of the invention, it is possible to employ a configuration in which, in the case in which at least the portion in front of the symbols other than the last stop displayed symbol takes on the non-transmissive condition, a varying display period of the last stop displayed symbol becomes longer than in other cases. 
     In the gaming machine of the invention, it is possible to employ a configuration in which, in the case in which the combination of the plurality of symbols reaches the heretofore described condition (the so-called “lizhi”, which is the condition in which the combination lacks one symbol of the prescribed combination), at least the portion in front of the symbols other than the last stop displayed symbol takes on the non-transmissive condition on condition that the image displayed on the second display device is a specified image. 
     In the gaming machine of the invention, it is possible to employ a configuration in which, immediately after the varying display of the plurality of symbols is started, at least the portion in front of the symbols other than the last stop displayed symbol takes on the non-transmissive condition. As used herein, “immediately after” refers, at least, to a period from the varying display of the symbols being started until a stop display of one symbol is carried out but, preferably, is substantially the same point as a point at which the varying display of the symbols is started. 
     In the gaming machine of the invention, it is possible to employ a configuration in which, apart from the case in which the combination of the plurality of symbols reaches the heretofore described condition (the condition in which the combination lacks one symbol of the prescribed combination), in a case in which the combination becomes a combination corresponding to a bonus game which is a gaming mode advantageous to a player, at least the portion in front of the symbols other than the last stop displayed symbol takes on the non-transmissive condition. 
     According to the invention, in the condition in which the combination of the plurality of symbols lacks one symbol of the prescribed combination (the lizhi condition), it is possible to carry out the effect rich in impact without giving the feeling of boredom. 
     Additional objects and advantage of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE INVENTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principals of the invention. 
         FIG. 1  is a perspective view schematically showing a gaming machine according to an embodiment of the invention; 
         FIG. 2  is a schematic diagram showing an example of a column of symbols depicted on an outer peripheral surface of each reel; 
         FIG. 3  is a diagram for illustrating a correlation between a plurality of kinds of winning combination and an establishment possibility of, and a payout quantity for, each winning combination; 
         FIG. 4  is a block diagram showing an internal configuration of the gaming machine shown in  FIG. 1 ; 
         FIG. 5  is a flowchart showing a sub-routine of a game execution process; 
         FIG. 6  is a flowchart showing a sub-routine of a stop symbol determination process; 
         FIGS. 7A and 7B  are diagrams each showing an example of a lizhi effect table; 
         FIGS. 8A and 8B  are views showing an example of an image displayed on a lower image display panel; 
         FIGS. 9A and 9B  are views showing an example of an image displayed on the lower image display panel; 
         FIGS. 10A and 10B  are views showing an example of an image displayed on the lower image display panel; 
         FIGS. 11A and 11B  are views showing an example of an image displayed on the lower image display panel; 
         FIGS. 12A and 12B  are views showing an example of an image displayed on the lower image display panel; 
         FIGS. 13A and 13B  are views showing an example of an image displayed on the lower image display panel; and 
         FIG. 14  is a view showing an example of an image displayed on the lower image display panel. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description, a description will be given, centered on characteristic portions, in such a way as to enable an easier understanding of the invention. The invention, not being limited to an embodiment described in the following detailed description, can also be applied to other embodiments, and its range of application is diverse. Also, the terminology and phraseology used in this specification are used to accurately describe the invention, and not used to limit the interpretation of the invention. Also, it is deemed easy for those skilled in the art to deduce, from the concept of the invention described in this specification, another configuration, system, method or the like included in the concept of the invention. Consequently, the description of the claims has to be considered to include a uniform configuration without departing from the scope of the technical idea of the invention. Also, the aim of the abstract is to allow the patent office and general public institutions, or engineers or the like who, belonging to the art, are not skilled in patent, legal or technical terms, to immediately judge technical contents of the invention and its essence from a simple investigation. Consequently, the abstract is not intended to limit the scope of the invention which should be evaluated from the description of the claims. Also, in order to fully understand the object of the invention and the unique advantages of the invention, it is desirable to interpret them by making full allowance for an already disclosed document or the like. 
     The following detailed description includes processes executed by a computer. The following description and expressions are given for the purpose of the most efficient understanding of those skilled in the art. In this specification, each step used to derive one result should be understood as a self-consistent process. Also, in each step, a transmission and reception, a recording or the like of an electric or magnetic signal is carried out. In the process of each step, although this kind of signal is expressed in a form of a bit, a value, a symbol, a letter, a term, a number or the like, it is necessary to keep in mind that they are used merely for convenience of explanation. Also, although the processes of each step are sometimes described using terms common to those of human behavior, the processes described in this specification are executed by each kind of device in principle. Also, other configurations required to carry out each step will be obvious from the following description. 
       FIG. 1  is a perspective view schematically showing a gaming machine according to an embodiment of the invention. 
     In this embodiment, a gaming machine  10  is a slot machine. However, in the invention, the gaming machine not being limited to the slot machine, it is also acceptable that it is, for example, a so-called single game machine, such as a video slot machine or a video card game machine, or a so-called mass game machine (a multi-terminal gaming machine) or the like which carries out a game, such as a horse racing game, a bingo game or a lottery, which requires a prescribed time until a result is displayed. 
     In the gaming machine  10 , a coin, a bill or electronic valuable information equivalent to them is used as a game medium. However, in the invention, the game medium can include, but is not particularly limited to, for example, a medal, a token, electronic money and a ticket. The ticket can include, but is not particularly limited to, for example, a bar-coded ticket, such as to be described hereafter, and the like. 
     The gaming machine  10  includes a cabinet  11 , a top box  12  disposed on top of the cabinet  11 , and a main door  13  provided on a front of the cabinet  11 . Three reels  14  ( 14 L,  14 C and  14 R) are rotatably provided inside the cabinet  11 . These reels  14  correspond to a first display device. A symbol column with 22 symbols is depicted on an outer peripheral surface of each reel  14 . 
     A lower image display panel  16  is provided in front of the reels  14  in the main door  13 . The lower image display panel  16  including a transparent liquid crystal panel and a liquid crystal shutter disposed on a back thereof, during a game, various information relating to the game, an effect image and the like are displayed on the transparent liquid crystal panel. The lower image display panel  16  corresponds to a second display device. A credit quantity display portion  31  and a payout quantity display portion  32  are set in the lower image display panel  16 . A number of coins credited is displayed in the credit quantity display portion  31  by means of an image. A number of coins to be paid out in the event that a combination of symbols stop displayed on a win line L is a prescribed combination is displayed in the payout quantity display portion  32  by means of an image. 
     Three display windows  15  ( 15 L,  15 C and  15 R), being formed in the lower image display panel  16  in such a way as to make its rear face visible, three of the symbols depicted on the outer peripheral surface of each reel  14  are displayed via each display window  15 . The display windows  15  can be switched to a transmissive condition or a non-transmissive condition by means of the liquid crystal shutter. The switching to the transmissive condition or the non-transmissive condition can be carried out individually for each of the display windows  15 L,  15 C and  15 R. Also, it not always being necessary that the switching to the transmissive condition and the non-transmissive condition is carried out in an instant, it is also possible, for example, by gradually increasing a non-transmissive area in a case in which the display window  15 L is in the transmissive condition, to take time to switch the display windows  15  from the transmissive condition to the non-transmissive condition. As this kind of liquid crystal shutter, being described in, for example, Japanese Unexamined Patent Publication Nos. 2004-8705, 2004-73651 and the like, is publicly known, a description will be omitted here. One win line L passing horizontally through the three display windows  15  is formed on the lower image display panel  16 . The win line L regulates a combination of symbols. In the event that a combination of symbols stop displayed on the win line L is the prescribed combination, a number of coins corresponding to the combination and a number of coins inserted (a BET quantity) is paid out. 
     Furthermore, a touch sensitive screen  69 , not shown, being provided on a front surface of the lower image display panel  16 , it is possible for a player to input various instructions by operating the touch sensitive screen  69 . 
     A control panel  20  having a plurality of buttons  23  to  27  with which instructions relating to a game implementation are input by the player, a coin acceptor  21  which accepts coins into the cabinet  11 , and a bill validator  22  are provided below the lower image display panel  16 . 
     The control panel  20  is provided with a SPIN button  23 , a CHANGE button  24 , a CASHOUT button  25 , a 1-BET button  26  and a MAX BET button  27 . The SPIN button  23  is for inputting an instruction to start a rotation of the reels  14 . The CHANGE button  24  is used to request a change of money from an attendant of a game establishment. The CASHOUT button  25  is for inputting an instruction to pay out credited coins into a coin tray  18 . 
     The 1-BET button  26  is for inputting an instruction to bet one coin, from among the credited coins, on the game. The MAX BET button  27  is for inputting an instruction to bet a maximum number (in this embodiment, 50) of coins, from among the credited coins, which can be bet on one game. 
     The bill validator  22 , as well as recognizing a legitimacy of a bill, accepts the legitimate bill into the cabinet  11 . It is also acceptable that the bill validator  22  is configured in such a way as to be able to read a bar-coded ticket  39  to be described hereafter. A belly glass  34  on which is depicted a character or the like of the gaming machine  10  is provided on a lower front of the main door  13 , that is, below the control panel  20 . 
     An upper image display panel  33  is provided on a front of the top box  12 . The upper image display panel  33  includes a liquid crystal panel, on which is displayed, for example, an image representing an introduction of game contents or an explanation of game rules. 
     Also, a speaker  29  is provided on the top box  12 . A ticket printer  35 , a card reader  36 , a data indicator  37  and a keypad  38  are provided below the upper image display panel  33 . The ticket printer  35  prints a bar code into which are encoded data, such as a credit quantity, a date and time, and an identification number of the gaming machine  10 , on a ticket, and outputs the ticket as the bar-coded ticket  39 . The player can cause another gaming machine to read the bar-coded ticket  39  and play a game on the relevant gaming machine, or can change the bar-coded ticket  39  into a bill or the like at a prescribed place of the game establishment (for example, a cashier in a casino). 
     The card reader  36  carries out a reading of data from a smart card and a writing of the data onto the smart card. The smart card is a card which the player possesses, on which are stored, for example, data for identifying the player and data relating to a history of a game which the player has played. It is also acceptable that data equivalent to the coin, bill or credit are stored on the smart card. Also, it is also acceptable to employ a magnetic stripe card in place of the smart card. The data indicator  37 , having a fluorescent display or the like, indicates, for example, data read by the card reader  36  or data input by the player via the keypad  38 . The keypad  38  is for inputting instructions or data relating to a ticketing or the like. 
       FIG. 2  is a schematic diagram showing the column of symbols depicted on the outer peripheral surface of each reel. 
     22 symbols are depicted on the outer peripheral surface of each of the left reel  14 L, the central reel  14 C and the right reel  14 R. The symbols depicted on the reels  14  differ between one column and another. Each symbol column is configured by combining symbols “JACKPOT 7”, “BLUE 7”, “BELL”, “CHERRY”, “STRAWBERRY”, “PLUM”, “ORANGE” and “APPLE”. In the figure, code numbers in a left section are allotted to symbols in a right section. Regarding “JACKPOT 7”, “BLUE 7”, “BELL”, “CHERRY”, “STRAWBERRY”, “PLUM” and “ORANGE”, in the event that three of a kind are stop displayed on the win line L, a predetermined credit quantity is added as a credit owned by the player. Also, regarding “CHERRY” and “ORANGE”, even in the event that either of them or two of a kind are stop displayed on the win line L, a predetermined credit quantity is added as the credit owned by the player, in accordance with the number. 
     “APPLE” is a bonus game trigger (a symbol for allowing a transition to a bonus game). In the event that three “APPLE&#39;s” are stop displayed on the win line L, it is possible to make a transition to the bonus game. In this embodiment, the bonus game is a free game (a game which can be played a prescribed number of times without betting any coins). 
     The columns of the symbols depicted on the reels  14 , when a game is started by depressing the SPIN button  23  after depressing the 1-BET button  26  or the MAX BET button  27 , are displayed scrolling from a top to a bottom in the display windows  15 , in conjunction with a rotation of the reels  14 , and, after a prescribed time elapses, are stop displayed in the display windows  15 , in conjunction with a stopping of the rotation of the reels  14 . Furthermore, various winning combinations being fixed in advance based on symbol combinations, when a symbol combination corresponding to a winning combination is stopped on the win line L, a coin payout quantity corresponding to the winning combination is added to the credit owned by the player. Also, when the bonus game trigger is established, the bonus game occurs. 
     Herein, a description will be given of the winning combinations in this embodiment. 
       FIG. 3  is a diagram illustrating a relationship between a plurality of kinds of winning combination and a possibility of establishment of, and a payout quantity for, each winning combination. The possibility of establishment of each winning combination shown in  FIG. 3  is for a case in which a payout ratio in other than the bonus game is 88%. The establishment possibility shown in the figure shows a possibility that, in a case in which a code number of each reel  14  has been determined based on three random numbers with reference to symbol weighing data to be described hereafter, the relevant winning combination is established. That is, the establishment possibility is not based on a correlation of a random number with each winning combination. 
     The possibility of establishment of the bonus game trigger is 0.5%. When the bonus game trigger is won, three “APPLE” symbols are stop displayed on the win line L, and the bonus game occurs. In the bonus game, a number of free games fixed by a selection is executed. The possibility of establishment of “JACKPOT 7” is 0.5%. When this winning combination is established, three “JACKPOT 7” symbols are stop displayed on the win line L, and 30 coins are paid out for each coin inserted. The lower the establishment possibility, the higher the payout quantity set. However, in the event that a symbol combination which forms none of the winning combinations shown in  FIG. 3  is stop displayed, it is a loss, and no payout of coins is carried out. 
       FIG. 4  is a block diagram showing an internal configuration of the gaming machine shown in  FIG. 1 . 
     A gaming board  50  includes a CPU (Central Processing Unit)  51 , an ROM  55 , a boot ROM  52 , a card slot  53 S compatible with a memory card  53 , and an IC socket  54 S compatible with a GAL (Generic Array Logic)  54 , which are mutually connected via an internal bus. 
     The memory card  53 , including a nonvolatile memory such as Compact Flash (a registered trademark), stores a game program and a game system program. A selection program is included in the game program. The selection program is a program for determining symbols (code numbers corresponding to the symbols) of the reels  14  stop displayed on the win line L. Symbol weighing data corresponding to each of a plurality of kinds of payout ratio (for example, 80%, 84% and 88%) are included in the selection program. The symbol weighing data are data which, regarding each of three reels  14 , indicate a correlation between the code number of each symbol (refer to  FIG. 2 ) and one or a plurality of random numbers belonging to a prescribed range of numbers (0 to 255). A payout ratio being fixed based on payout ratio setting data transmitted from the GAL  54 , a selection is carried out based on symbol weighing data corresponding to this payout ratio. 
     Also, the card slot  53 S, being configured in such a way that the memory card  53  can be inserted into and removed from it, is connected to a mother board  40  via an IDE bus. Consequently, by removing the memory card  53  from the card slot  53 S, writing another game program and game system program into the memory card  53 , and inserting the relevant memory card  53  into the card slot  53 S, it is possible to change a type and contents of the game carried out on the gaming machine  10 . A program relating to a game implementation is included in the game program. Also, image data and sound data transmitted during the game are included in the game program. 
     The GAL  54  is a kind of PLD having an OR fixed array structure. The GAL  54  including a plurality of input ports and output ports, when prescribed data are input into the input ports, data corresponding to the data are output from the output ports. The data output from the output ports are the heretofore described payout ratio setting data. 
     Also, the IC socket  54 S, being configured in such a way that the GAL  54  can be inserted into and removed from it, is connected to the mother board  40  via a PCI bus. Consequently, by replacing the GAL  54  with another GAL  54 , it is also possible to change the payout ratio setting data. 
     The CPU  51 , the ROM  55  and the boot ROM  52 , which are mutually connected via the internal bus, are connected to the mother board  40  via a PCI bus. 
     The mother board  40 , being configured by using a general-purpose mother board available on the market (a printed circuit board mounted with basic parts of a personal computer), includes a main CPU  41 , an ROM (Read Only Memory)  42 , an RAM (Random Access Memory)  43  and a communication interface  44 . The main CPU  41  corresponds to a controller. 
     The ROM  42  includes a memory device such as a flash memory, in which are stored a program, such as a BIOS (Basic Input/Output System), executed by the main CPU  41 , and permanent data. When the BIOS is executed by the main CPU  41 , as well as a process of initializing a prescribed peripheral device being carried out, a process of downloading the game program and game system program stored in the memory card  53  via a gaming board  50  is started. In the invention, it is also acceptable that the ROM  42  is either capable or incapable of rewriting the contents. 
     Data and a program used for the main CPU  41  to operate are stored in the RAM  43 . Also, the RAM  43  can store the game program. The RAM  43  is a memory in the invention. Furthermore, data such as a credit quantity, and an insertion quantity and a payout quantity in one game, are stored in the RAM  43 . 
     Also, a main body PCB (Printed Circuit Board)  60  and a door PCB  80 , to be described hereafter, are each connected to the mother board  40  via a USB. Furthermore, a power unit  45  is connected to the mother board  40 . 
     An instrument or a device, which generates an input signal to be input into the main CPU  41 , and an instrument or a device, an operation of which is controlled by a control signal transmitted from the main CPU  41 , are connected to the main body PCB  60  and the door PCB  80 . The main CPU  41 , based on the input signal input into the main CPU  41 , by executing the game program stored in the RAM  43 , carries out a prescribed calculation process, and stores a result thereof in the RAM  43 , or transmits the control signal to each instrument or device as a control process with respect to each instrument or device. 
     A lamp  30 , a sub-CPU  61 , a hopper  66 , a coin detector  67 , a graphic board  68 , the speaker  29 , the touch sensitive screen  69 , the bill validator  22 , the ticket printer  35 , the card reader  36 , a key switch  38 S and the data indicator  37  are connected to the main body PCB  60 . The lamp  30 , based on the control signal transmitted from the main CPU  41 , comes on in a prescribed pattern. 
     The sub-CPU  61  carries out a control of the rotation and stopping of the reels  14  ( 14 L,  14 C and  14 R). A motor drive circuit  62  including an FPGA (Field Programmable Gate Array)  63  and a driver  64  is connected to the sub-CPU  61 . The FPGA  63 , being an electronic circuit such as a programmable LSI, functions as a control circuit of stepping motors  70 . The driver  64  functions as an amplifier circuit for pulses input into the stepping motors  70 . The stepping motors  70  ( 70 L,  70 C and  70 R) carrying out the rotation of the corresponding reels  14  are connected to the motor drive circuit  62 . The stepping motors  70  are 1-2 phase excitation type stepping motors. 
     Also, an index detection circuit  65  and a position change detection circuit  71  are connected to the sub-CPU  61 . The index detection circuit  65  detects a position (an index to be described hereafter) of each rotating reel  14  and, furthermore, can detect a loss of synchronism of each reel  14 . The position change detection circuit  71  detects a change of a stop position of each reel  14  after the rotation of each reel  14  stops. The position change detection circuit  71  is configured in such a way that, by detecting, for example, fins (not shown) attached to inner portions of each reel  14  at prescribed intervals, it is possible to detect the change of the stop position of each reel  14 . 
     The hopper  66 , being disposed in the cabinet  11 , based on the control signal transmitted from the main CPU  41 , pays out a prescribed number of coins into the coin tray  18  through a coin payout opening  19 . The coin detector  67 , being provided inside the coin payout opening  19 , in a case of detecting that the prescribed number of coins has been paid out through the coin payout opening  19 , transmits an input signal to the main CPU  41 . 
     The graphic board  68 , based on the control signal transmitted from the main CPU  41 , as well as controlling an image display on the upper image display panel  33  and the lower image display panel  16 , carries out a control of switching each display window  15  of the lower image display panel  16  to the transmissive condition or the non-transmissive condition. The credit quantity stored in the RAM  43  is displayed in the credit quantity display portion  31  of the lower image display panel  16 . Also, the coin payout quantity is displayed in the payout quantity display portion  32  of the lower image display panel  16 . The graphic board  68  includes a VDP (Video Display Processor), which generates image data based on the control signal transmitted from the main CPU  41 , a video RAM, which temporarily stores the image data generated by the VDP, a microcomputer, which carries out a control of the liquid crystal shutter, a drive circuit, and the like. Image data used for the VDP to generate the image data are included in the game program which has been read from the memory card  53  and stored in the RAM  43 . 
     The bill validator  22 , as well as recognizing the legitimacy of the bill, accepts the legitimate bill into the cabinet  11 . The bill validator  22 , when accepting the legitimate bill, transmits an input signal to the main CPU  41 , based on a value of the bill. The main CPU  41  stores a credit quantity corresponding to the value of the bill transmitted via the input signal in the RAM  43 . 
     The ticket printer  35 , based on the control signal transmitted from the main CPU  41 , prints a bar code into which are encoded data stored in the RAM  43 , such as the credit quantity, the date and time, and the identification number of the gaming machine  10 , on a ticket, and outputs the ticket as the bar-coded ticket  39 . 
     The card reader  36  reads the data from the smart card and transmits them to the main CPU  41  or, based on the control signal from the main CPU  41 , carries out the writing of the data onto the smart card. The key switch  38 S, being provided on the keypad  38 , transmits a prescribed input signal to the main CPU  41  when the keypad  38  is operated by the player. 
     The data indicator  37 , based on the control signal transmitted from the main CPU  41 , indicates the data read by the card reader  36  and the data input by the player via the keypad  38 . 
     The control panel  20 , a reverter  21 S, a coin counter  21 C and a cold cathode tube  81  are connected to the door PCB  80 . The control panel  20  is provided with a SPIN switch  23 S corresponding to the SPIN button  23 , a CHANGE switch  24 S corresponding to the CHANGE button  24 , a CASHOUT switch  25 S corresponding to the CASHOUT button  25 , a 1-BET switch  26 S corresponding to the 1-BET button  26 , and a MAX BET switch  27 S corresponding to the MAX BET button  27 . Each switch  235  to  27 S, when the corresponding buttons  23  to  27  is operated by the player, transmits an input signal to the main CPU  41 . 
     The coin counter  21 C, being provided inside the coin acceptor  21 , recognizes a legitimacy of a coin inserted into the coin acceptor  21  by the player. Coins other than the legitimate coin are ejected from the coin payout opening  19 . Also, the coin counter  21 C, when detecting the legitimate coin, transmits an input signal to the main CPU  41 . 
     The reverter  21 S, operating based on the control signal transmitted from the main CPU  41 , sorts coins recognized as the legitimate coins by the coin counter  21 C into a cash box (not shown) or the hopper  66 , disposed in the gaming machine  10 . That is, in the event that the hopper  66  is filled with coins, the legitimate coins are sorted into the cash box by the reverter  21 S while, in the event that the hopper  66  is not filled with coins, the legitimate coins are sorted into the hopper  66 . The cold cathode tube  81 , functioning as a back light disposed on a back of each of the lower image display panel  16  and the upper image display panel  33 , comes on based on the control signal transmitted from the main CPU  41 . 
     Next, a description will be given of processes carried out in the gaming machine  10 . 
     The main CPU  41 , by reading and executing the game program, implements the game. 
       FIG. 5  is a flowchart showing a sub-routine of a game execution process. 
     In the game execution process, first, the main CPU  41  judges whether or not a coin has been bet (step S 10 ). In this process, the main CPU  41  judges whether or not it has received an input signal transmitted from the 1-BET switch  26 S when the 1-BET button  26  is operated, or whether or not it has received an input signal transmitted from the MAX BET switch  27 S when the MAX BET button  27  is operated. The main CPU  41 , if it judges that no coin has been bet, returns the process to step S 10 . 
     Meanwhile, the main CPU  41 , if it judges in step S 10  that coins have been bet, in accordance with a number of the coins bet, carries out a process of reducing the credit quantity stored in the RAM  43  (step S 11 ). If the number of coins bet is larger than the credit quantity stored in the RAM  43 , the main CPU  41 , without carrying out the process of reducing the credit quantity stored in the RAM  43 , returns the process to step S 10 . Also, if the number of coins bet exceeds an upper limit (in this embodiment, 50) which can be bet on one game, the main CPU  41 , without carrying out the process of reducing the credit quantity stored in the RAM  43 , advances the process to step S 12 . 
     Next, the main CPU  41  judges whether or not the SPIN button  23  has been turned on (step S 12 ). In this process, the main CPU  41  judges whether or not it has received an input signal transmitted from the SPIN switch  23 S when the SPIN button  23  has been depressed. 
     The main CPU  41 , if it judges that the SPIN button  23  has not been turned on, returns the process to step S 10 . If the SPIN button  23  has not been turned on (for example, if an instruction to finish the game has been input without the SPIN button  23  being turned on), the main CPU  41  cancels a reduction result of step S 11 . 
     Meanwhile, the main CPU  41 , if it judges in step S 12  that the SPIN button  23  has been turned on, carries out a stop symbol determination process (step S 13 ). 
     Herein, a description will be given of the stop symbol determination process. 
       FIG. 6  is a flowchart showing a sub-routine of the stop symbol determination process which is called up and executed in step S 13  of the sub-routine shown in  FIG. 5 . This process is one which is carried out by the main CPU  41  executing the selection program stored in the RAM  43 . 
     First, the main CPU  41 , by executing a random number generation program included in the selection program, samples one random number corresponding to each of the three reels  14  from within the range of numbers 0 to 255 (step S 30 ). Next, the main CPU  41 , referring to the symbol weighing data corresponding to the payout ratio setting data which have been transmitted from the GAL  54  and stored in the RAM  43 , determines code numbers of the reels  14  based on the selected three random numbers (refer to  FIG. 2 ) (step S 31 ). The code numbers of the reels  14  correspond to code numbers of symbols stop displayed on the win line L. The main CPU  41 , by determining the code numbers of the reels  14 , determines a winning combination (refer to  FIG. 3 ). 
     Next, the main CPU  41  judges whether or not the determined winning combination is a combination in which the bonus game trigger constitutes the lizhi, that is, a combination which includes two or more bonus game triggers (step S 32 ). The main CPU  41 , if it judges that the winning combination is not the combination in which the bonus game trigger constitutes the lizhi, finishes this sub-routine. Meanwhile, the main CPU  41 , if it judges that the winning combination is the combination in which the bonus game trigger constitutes the lizhi, judges whether or not the winning combination is a combination which establishes the bonus game trigger, that is, a combination which includes three bonus game triggers (step S 33 ). The main CPU  41 , if it judges that the winning combination is not the combination which establishes the bonus game trigger, sets a losing lizhi flag to “ON” in the RAM  43  (step S 34 ), and finishes this sub-routine. Meanwhile, the main CPU  41 , if it judges that the winning combination is the combination which establishes the bonus game trigger, sets a bonus lizhi flag to “ON” in RAM  43  (step S 35 ), and finishes this sub-routine. Subsequently, the main CPU  41  advances the process to step S 14  of the sub-routine shown in  FIG. 5 . 
     Next, the main CPU  41  carries out an effect determination process (step S 15 ) 
     In this process, the main CPU  41 , by executing the random number generation program, samples one random number from within the range of numbers 0 to 255. Meanwhile, the main CPU  41 , referring to the flag or the like set in the RAM  43 , selects an effect table corresponding to a gaming mode from among effect tables stored in the RAM  43 . Then, the main CPU  41 , referring to the effect table, selects an effect corresponding to the sampled random number. For example, the main CPU  41 , when the losing lizhi flag is set to “ON”, selects the effect by referring to a lizhi effect table for when setting the losing lizhi flag (refer to  FIG. 7A ). Also, the main CPU  41 , when the bonus game lizhi flag is set to “ON”, selects the effect by referring to a lizhi effect table for when setting the bonus lizhi flag (refer to  FIG. 7B ). 
       FIG. 7A  is a diagram showing an example of the lizhi effect table for when setting the losing lizhi flag. 
     Effects “normal lizhi”, “telescope lizhi (failure)” and “bird lizhi (failure)” have their appearance ratios fixed by allotting them respectively with the random numbers (not shown) belonging to the prescribed range of numbers. Also, in the effect “normal lizhi”, a non-transmission display is not carried out, and a lizhi period is also short. Meanwhile, in the effects “telescope lizhi (failure)” and “bird lizhi (failure)”, the non-transmission display is carried out, and the lizhi period is also long (a so-called long lizhi). 
       FIG. 7B  is a diagram showing an example of the lizhi effect table for when setting the bonus lizhi flag. 
     Effects “normal lizhi”, “telescope lizhi (success)”, “telescope lizhi (comeback)”, “bird lizhi (success) and “bird lizhi (comeback)” have their appearance ratios fixed by allotting them respectively with random numbers (not shown) belonging to the prescribed range of numbers. Also, in the effect “normal lizhi”, the non-transmission display is not carried out, and the lizhi period is also short. Meanwhile, in the effects “telescope lizhi (success)”, “telescope lizhi (comeback)”, “bird lizhi (success) and “bird lizhi (comeback)”, the non-transmission display is carried out, and the lizhi period is also long (the long lizhi). Each heretofore described effect will be described in detail hereafter. 
     Next, the main CPU  41  starts a rotation of all the reels  14  (step S 15 ). Subsequently, the main CPU  41  judges whether or not the effect selected in step S 14  is accompanied by the non-transmission display (step S 16 ) and, if it judges that the effect is accompanied by the non-transmission display, referring to a result or the like of the stop symbol determination process (step S 13 ), carries out a control of putting display areas, other than a display area (a display window  15 ) in front of a reel  14  which stops last, into the non-transmissive condition (step S 17 ). Then, the main CPU  41  carries out the effect determined in the process of step S 14  (step S 18 ). The main CPU  41  carries out, for example, a process of displaying an image corresponding to the heretofore described effect on each image display panel  16  and  33 , or emitting a sound (background music, a sound effect, a voice or the like) corresponding to the image from the speaker  29 . It is also acceptable to carry out a non-transmission control of the display area after starting the effect. 
     Subsequently, the main CPU  41  judges whether or not a time has come to stop one of the three reels  14  (step S 19 ) and, if it judges that the time has come, carries out a process of stopping a rotation of the relevant reel  14  (step S 20 ), while the main CPU  41 , if it judges that the time has not come to stop the reel  14 , returns the process to step S 18 . In a case of stopping a last rotating reel  14 , in the event that the long lizhi has been selected in step S 14 , the main CPU  41  sets a rotation period of the reel  14  which stops last to be long. Continuing on, the main CPU  41  judges whether or not all the reels  14  have stopped (step S 21 ) and, if not all the reels  14  have stopped, returns the process to step S 18 , and repeats the processes of steps S 18  to S 20  until all the reels  14  stop. 
     If all the reels  14  have stopped, the main CPU  41  judges whether or not the bonus game trigger has been established (step S 22 ). The main CPU  41 , if it judges that the bonus game trigger has been established, reads a program for carrying out the bonus game from the RAM  43 , and executes a bonus game process (step S 23 ). 
     Meanwhile, the main CPU  41 , if it judges that the bonus game trigger has not been established, judges whether or not a winning combination has been established (step S 24 ). The main CPU  41 , if it judges that a winning combination has been established, carries out a payout of coins corresponding to the insertion quantity and the winning combination (step S 25 ). 
     In a case of carrying out a storing of coins, the main CPU  41  carries out a process of adding the credit quantity stored in the RAM  43 . Meanwhile, in a case of carrying out the payout of coins, the main CPU  41  transmits the control signal to the hopper  66 , and carries out a payout of a prescribed number of coins. After the process of step S 16 , the main CPU  41 , after the process of step S 18 , or if it judges that no winning combination has been established in step S 24 , finishes this sub-routine. 
     Next, a description will be given, using  FIGS. 8A to 14 , of an image which is displayed on the lower image display panel  16  by the process of step S 18  of the sub-routine shown in  FIG. 5  being carried out. 
       FIGS. 8A to 14  are views showing examples of the image displayed on the lower image display panel. 
     In  FIGS. 8A to 14 , N designates a non-transmissive area, and T 1  to T 3  designate transmissive areas. The reels  14 L,  14 C and  14 R become visible via the transmissive areas T 1  to T 3  respectively. C designates a main character, and B designates a bird character. S designates a field of view of a telescope. 
     Telescope Lizhi (Success) 
     When the SPIN button  23  (refer to  FIG. 4 ) is depressed, the image shown in  FIG. 8A  is displayed on the lower image display panel  16 . As shown in  FIG. 8A , an image representing the main character C on a voyage is displayed in the non-transmissive area N of the lower image display panel  16 . Meanwhile, portions corresponding to the display windows  15  (not shown) becoming the transmissive areas T 1  to T 3 , the reels  14 L,  14 C and  14 R are visible via the transmissive areas T 1  to T 3 . Subsequently, the image switches to a scene of looking through the telescope and, as shown in  FIG. 8B , an image S representing the field of view of the telescope is displayed in a form of moving from the bottom to the top of the lower image display panel  16 . At this time, a control of putting the areas in front of the reels  14 L and  14 C into the non-transmissive condition is carried out, and the transmissive areas T 1  and T 2  narrow gradually and vanish. Next, as shown in  FIG. 9A , an image representing a foggy shadow is displayed in the image S representing the field of view of the telescope. Also, a rotation period of the right reel  14 R (a varying display period of the symbols depicted on the reel  14 R) is longer than a period of the normal lizhi (refer to  FIG. 7B ) in which no non-transmission control is carried out (the long lizhi). Subsequently, as shown in  FIG. 9B , an image is displayed in which the fog has cleared and a ghost ship appears. Then, the rotation of the right reel  14 R stops, and the bonus game trigger is stop displayed. In this case, the bonus game is subsequently carried out. 
     Telescope Lizhi (Failure) 
     After the image shown in  FIG. 9A  is displayed, as shown in  FIG. 10A , as well as an image in which the fog has cleared and a mirage appears being displayed, the rotation of the right reel  14 R stops, and a symbol (in the figure, “CHERRY”) other than the bonus game trigger may be stop displayed. In this case, no bonus game is subsequently carried out. 
     Telescope Lizhi (Comeback) 
     After the image shown in  FIG. 10A  is displayed, the rotation of the right reel  14 R starts again and, as shown in  FIG. 10B , a color of the image S representing the field of view of the telescope becomes darker, and an image representing the bird character B may be displayed therein. In this case, the rotation of the reel  14 R subsequently stops, the bonus game trigger is stop displayed, and the bonus game is carried out. 
     Bird Lizhi (Success) 
     When the SPIN button  23  (refer to  FIG. 4 ) is depressed, the image shown in  FIG. 11A  is displayed on the lower image display panel  16 . As shown in  FIG. 11A , the image representing the bird character B is displayed in the non-transmissive area N of the lower image display panel  16  in a form of crossing a screen. Meanwhile, the portions corresponding to the display windows  15  (not shown) becoming the transmissive areas T 1  to T 3 , the reels  14 L,  14 C and  14 R are visible via the transmissive areas T 1  to T 3 . Subsequently, an image representing a face of the main character C is displayed in a cut-in form. At this time, the control of putting the areas in front of the reels  14 L and  14 C into the non-transmissive condition is carried out, and the transmissive areas T 1  and T 2  gradually narrow and vanish. Next, as shown in  FIG. 12A , an image representing an aspect in which the main character C tries to catch the bird character using a rope is displayed. Also, the rotation period of the right reel  14 R (the varying display period of the symbols depicted on the reel  14 R) is longer than the period of the normal lizhi (refer to  FIG. 7B ) in which no non-transmission control is carried out (the long lizhi). Subsequently, an image representing in enlarged dimension the rope flying toward the bird character is displayed (refer to  FIG. 13A ). 
     When an image representing an aspect in which the bird character is caught with the rope is displayed, as shown in  FIG. 12B , an image representing an aspect in which the main character C rides on the bird character and aims for a treasure is displayed. Then, the rotation of the right reel  14 R stops, and the bonus game trigger is stop displayed. In this case, the bonus game is subsequently carried out. 
     Bird Lizhi (Failure) 
     After the image shown in  FIG. 12B  is displayed, an image representing an aspect in which the bird character has not been caught with the rope is displayed, as shown in  FIG. 13B , an image representing an aspect in which, as well as the bird character B fleeing, the main character C is disappointed is displayed, the rotation of the right reel  14 R stops, and a symbol (in the figure, “CHERRY”) other than the bonus game trigger may be stop displayed. In this case, no bonus game is subsequently carried out. 
     Bird Lizhi (Comeback) 
     After the image shown in  FIG. 13B  is displayed, the right reel  14 R starts rotating again and, as shown in  FIG. 14 , an image representing an aspect in which, as well as the bird character B coming back, the main character C is delighted may be displayed. In this case, the rotation of the reel  14 R subsequently stops, the bonus game trigger is stop displayed, and the bonus game is carried out. 
     As described heretofore, the gaming machine  10  according to the invention, being provided with the lower image display panel  16 , which can display an image and can be switched to the transmissive condition or the non-transmissive condition, in front of a plurality of symbols which can be variably displayed, in the event that a combination of the plurality of symbols reaches the lizhi, executes a process of putting a portion in front of symbols other than a last stop symbol into the non-transmissive condition. Also, the gaming machine  10 , in the case of putting the portion in front of the symbols other than the last stop symbol into the non-transmissive condition, executes a process of making a varying display period of the last stop symbol longer than in other cases. Also, the gaming machine  10 , in the event that the lizhi occurs, executes a process of putting the portion in front of the symbols other than the last stop symbol into the non-transmissive condition on condition that the image displayed on the lower image display panel  16  is a specified image (for example, the telescope lizhi or the bird lizhi). Also, the gaming machine  10 , immediately after the varying display of the plurality of symbols starts, executes the process of putting the portion in front of the symbols other than the last stop symbol into the non-transmissive condition. 
     Also, the gaming machine  10  executes a game control method of the invention in the following way. 
     That is, the gaming machine  10 , in the event that the combination of the plurality of symbols reaches the lizhi, puts a whole or a portion of the symbols other than the last stop symbol into an invisible condition. Also, the gaming machine  10 , in the case of putting the symbols other than the last stop symbol into the invisible condition, executes the process of making the varying display period of the last stop symbol longer than in other cases. Also, the gaming machine  10 , in the event that the lizhi occurs, puts the symbols other than the last stop symbol into the invisible condition on condition that the image displayed on the lower image display panel  16  is the specified image. 
     Also, the gaming machine  10 , immediately after the varying display of the plurality of symbols starts, puts the symbols other than the last stop symbol into the invisible condition. 
     In the invention, as described using  FIGS. 8A to 10B , it is possible to employ a configuration in which, in the case in which the non-transmission control is carried out, the image S representing the field of view of the telescope is displayed on a screen of the second display device for which the non-transmission control has been carried out, and furthermore, when the bonus game occurs, an image representing an aspect in which a prescribed phenomenon occurs (for example, a phenomenon in which the fog has cleared and the ghost ship appears) is displayed in the image representing the field of view. 
     Also, in the invention, as described using  FIGS. 11A to 14 , it is possible to employ a configuration in which, in the case in which the non-transmission control is carried out, an ally character (for example, the main character C) and a target character (for example, the bird character B) are displayed on the screen of the second display device for which the non-transmission control has been carried out, and furthermore, when the bonus game occurs, an image representing an aspect in which the ally character succeeds in catching the target character is displayed. 
     Furthermore, in the invention, it is also acceptable to carry out the varying display and stop display of the plurality of symbols on the display device and, in the event that the lizhi occurs, turn the symbols other than the last stop displayed symbol into a non-display on the relevant display device. 
     Although the embodiment of the invention has been described heretofore, it merely exemplifying a specific example and not particularly limiting the invention, a specific configuration of each component or the like can be changed in design as appropriate. Also, the advantages described in the embodiment of the invention being derived by merely citing most preferred advantages resulting from the invention, the advantages due to the invention are not limited to the ones described in the embodiment of the invention. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.