Patent Publication Number: US-8979632-B2

Title: Gaming machine and gaming method

Description:
BACKGROUND 
     (a) Field 
     The present invention generally relates to a gaming machine and a gaming method. 
     (b) Description of the Related Art 
     A gaming machine executes a game to rearrange symbols, and awards a benefit to the player according to a result of the rearranged symbols. Various gaming machines have been developed to meet players&#39; various preferences, so various features such as symbol patterns, gaming scenarios, side effects such as background sound and additional visual display, and reel spinning schemes have been varied. 
     A gaming machine operator wants the players to frequently play the games, thereby increasing their profits. However, visual effects that are provided by varying the above features are general effects that can be provided by gaming machines of other operators. Accordingly, there are limits to continuously attracting the players&#39; attention through only the above features. 
     SUMMARY 
     Aspects of the present invention provide a gaming machine, a gaming system, and a gaming method for continuously attracting the players&#39; attention. 
     According to an aspect of the present invention, a gaming machine including a first display, a second display, a memory and a controller is provided. The first display displays a game result. The second display includes a display panel and a door located in front of the display panel, and controls opening or closing of the door to control an exposure of the display panel. The memory stores a plurality of control data for controlling the door that correspond to a plurality of types of game results respectively and a plurality of display data that correspond to the plurality of control data respectively. Each of the plurality of control data includes at least one position data for determining a position of the door, and the at least one position data corresponds to at least one of a first position data for fully closing the door, a second position data for fully opening the door, or at least one third position data for partially opening the door. The controller executes a game to randomly determine a game result of the executed game, selects a control data corresponding to a type of the game result among the plurality of control data. Further, the controller displays on the display panel an image according to a display data that corresponds to the selected control data among the plurality of display data, controls the door using at least one position data of the selected control data, and displays the game result on the first display. 
     The controller may display the image on the display panel and control the door using the at least one position during a period between a start of the game and a display of the game result. 
     Each of the plurality of display data may include at least one object image, a display position data representing a position where the object image is displayed on the display panel, and a display timing data representing a timing when the object image is displayed on the display panel. The control data may be associated with the display position data and the display timing data of a corresponding display data to expose the object image through the door. 
     Each of the plurality of control data may further include at least one timing data that corresponds to the at least one position data and represents a timing when the door is moved to the position indicated by the corresponding position data. 
     The controller may trigger an additional game when the game result satisfies a predetermined condition. A plurality of rendering modes may be defined by the plurality of control data and the plurality of the display data, and may include a first rendering mode and a second rendering mode. In this case, a probability of the additional game being triggered when the controller renders the first rendering pattern may be different from a probability of the additional game being triggered when the controller renders the second rendering pattern. 
     A plurality of holes may be formed in the door. At least part of the plurality of display data may include at least one object image shown through at least part of the holes. 
     The first display may include a plurality of reels and a display window for showing the plurality of reels, and a plurality of holes that correspond to the plurality of reels respectively may be formed in the door. When a predetermined image are shown through at least one hole among the plurality of holes, the game result may include a predetermined symbol that is rearranged on at least one reel corresponding to at least one hole among the plurality of reels. 
     The door may include a left sliding door configured to be opened in a left direction from a center position for the door and a right sliding door configured to be opened in a right direction from the center position. 
     The game may include a normal mode game. The controller may trigger a chance mode game including a plurality of chance rounds when the game result of the normal mode game satisfies a first condition, and may determine a chance type of the chance mode game among a plurality of chance types and a control data and an display data corresponding to the determined chance type among the plurality of control data and the plurality of display data. Further, the controller may execute each chance round of the chance mode game according to the determined chance type by displaying on the display panel an image according to the determined display data and controlling the door using at least one position data of the determined control data. 
     The controller may trigger a bonus mode game when the game result of the normal mode game or a game result of the chance mode game satisfies a second condition, and may provide a player with an additional benefit according to the bonus mode game. In this case, a probability of the bonus mode game being triggered in the chance mode game may be higher than a probability of the bonus mode game being triggered in the normal mode game. 
     The plurality of chance types may include at least one chance type for showing a sign of the bonus mode game being triggered. The controller may show the sign of the bonus mode game being triggered by displaying on the display panel an image according to the determined display data and controlling the door using the at least one position data of the determined control data. 
     The plurality of chance types may include at least one chance type for showing a probability of the bonus mode game being triggered. The controller may show the probability of the bonus mode game being triggered by displaying on the display panel a predetermined image according to the determined display data and controlling the door using the at least one position data of the determined control data. 
     The predetermined image may be varied according to the probability of the bonus mode game being triggered. 
     The controller may close the door when the bonus mode game is triggered, to determines a bonus type among a plurality of bonus types for the bonus mode game, and may open the door and display an image for notifying the determined bonus type on the display panel. 
     According to another aspect of the present invention, a gaming method by a gaming machine is provided. The gaming machine includes a first display and a second display, and the second display includes a display panel and a door located in front of the display panel and controls opening or closing of the door to control an exposure of the display panel. The method includes executing a game to randomly determine a game result of the executed game, and selecting a control data corresponding to a type of the game result among a plurality of control data for controlling the door. Each of the plurality of control data include at least one position data for determining a position of the door, and the at least one position data corresponds to at least one of a first position data for fully closing the door, a second position data for fully opening the door, or at least one third position data for partially opening the door. The method further includes selecting a display data corresponding to the selected control data among a plurality of display data, displaying on the display panel an image according to the selected display data, controlling the door using at least one position data of the selected control data, and displaying the game result on the first display. 
     Displaying the image on the display panel and controlling the door using the at least one position may be performed during a period between a start of the game and a display of the game result. 
     Each of the plurality of display data may include at least one object image, a display position data representing a position where the object image is displayed on the display panel, and a display timing data representing timing when the object image is displayed on the display panel. The control data may be associated with the display position data and the display timing data of a corresponding display data to expose the object image through the door. 
     Each of the plurality of control data may further include at least one timing data that corresponds to the at least one position data and represents timing when the door is moved to the position indicated by the corresponding position data. 
     The method may further include triggering an additional game when the game result satisfies a predetermined condition. A plurality of rendering modes may be defined by the plurality of control data and the plurality of the display data, and may include a first rendering mode and a second rendering mode. In this case, a probability of the additional game being triggered when the controller renders the first rendering pattern may be different from a probability of the additional game being triggered when the controller renders the second rendering pattern. 
     A plurality of holes may be formed in the door. At least part of the plurality of display data may include at least one object image shown through at least part of the holes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a flowchart of a gaming method according to an embodiment of the present invention. 
         FIG. 2  is a schematic perspective view of a slot machine according to an embodiment of the present invention. 
         FIG. 3  is a schematic front view of a display window of a primary display in the slot machine shown in  FIG. 2  according to an embodiment of the present invention. 
         FIG. 4  and  FIG. 5  are schematic diagrams showing exemplary paylines according to an embodiment of the present invention. 
         FIGS. 6 and 7  are symbol code tables according to an embodiment of the present invention. 
         FIG. 8  is a layout view of a control panel in the slot machine shown in  FIG. 49  according to an embodiment of the present invention. 
         FIG. 9  is an electrical block diagram of the slot machine shown in  FIG. 49  according to an embodiment of the present invention. 
         FIG. 10A  is a block diagram of an electrical circuit of the reel assembly according to an embodiment of the present invention. 
         FIG. 10B  is a block diagram of the second display according to an embodiment of the present invention. 
         FIG. 11  is a functional block diagram of the game program executed by a main CPU of a motherboard in the slot machine shown in  FIG. 2  according to an embodiment of the present invention. 
         FIG. 12  is a schematic perspective view of a display device for a gaming machine according to an embodiment of the present invention. 
         FIG. 13  is a schematic exploded view of the display device shown in  FIG. 12 . 
         FIG. 14  is a schematic perspective view of the frame shown in  FIG. 12  and  FIG. 13  according to an embodiment of the present invention. 
         FIG. 15  is a schematic exploded view of the frame shown in  FIG. 14 . 
         FIG. 16  is a schematic perspective view of parts of the frame and the display panel assembly. 
         FIG. 17  and  FIG. 18  are schematic perspective views of a base assembly of the frame shown in  FIG. 14  according to an embodiment of the present invention. 
         FIG. 19  is a sectional view of the base assembly shown in  FIG. 17  and  FIG. 18  taken along line VIII-VIII. 
         FIG. 20  is a schematic perspective view of a right column of the frame shown in  FIG. 14  according to an embodiment of the present invention. 
         FIG. 21  is a schematic perspective view of a rear plate of the frame shown in  FIG. 14  according to an embodiment of the present invention. 
         FIG. 22  is a schematic perspective view of a top assembly of the frame shown in FIG.  14  according to an embodiment of the present invention. 
         FIG. 23  is a schematic perspective view of a top plate of the top assembly shown in  FIG. 22  according to an embodiment of the present invention. 
         FIG. 24  is a schematic rear perspective view of idle pulley supports and magnetic sensor supports of the top plate of the top assembly shown in  FIG. 22  according to an embodiment of the present invention. 
         FIG. 25  is a schematic exploded view of the display panel assembly according to an embodiment of the present invention. 
         FIG. 26  is a schematic perspective view of the shutter assembly the shutter assembly  300  according to an embodiment of the present invention. 
         FIG. 27  is a schematic exploded view of parts of the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention. 
         FIG. 28  is a sectional view of an upper track of the shutter assembly shown in  FIG. 26  taken along line XVII-XVII. 
         FIG. 29  is a rear view of an extension of the upper track of the shutter assembly shown in  FIG. 26 . 
         FIG. 30  is a schematic perspective view of a right connecting plate of the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention. 
         FIG. 31  is a schematic partially-exploded view of a right inner sliding door and a belt catcher in the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention. 
         FIG. 32  is a schematic exploded view of parts of the right inner sliding door and the belt catcher shown in  FIG. 31  according to an embodiment of the present invention. 
         FIG. 33  is a schematic perspective view of the belt catcher shown in  FIG. 32  according to an embodiment of the present invention. 
         FIG. 34  is a schematic rear perspective view of the belt catcher shown in  FIG. 33  according to an embodiment of the present invention. 
         FIG. 35  is a schematic partially-exploded view of a right outer sliding door in the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention. 
         FIG. 36  is a schematic perspective view of the driving unit shown in  FIG. 13  according to an embodiment of the present invention. 
         FIG. 37  is a schematic exploded view of a motor assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention. 
         FIG. 38  is a perspective view of the motor assembly shown in  FIG. 37  fixed in the right column of the frame according to an embodiment of the present invention. 
         FIG. 39  is a rear exploded view of the motor assembly and the right column of the frame according to an embodiment of the present invention. 
         FIG. 40  is a schematic exploded view of a drive pulley assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention. 
         FIG. 41  is a schematic exploded view of an idle pulley assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention. 
         FIG. 42  is a schematic perspective view of the idle pulley assembly shown in  FIG. 41  seated in the idle pulley support according to an embodiment of the present invention. 
         FIG. 43  is a schematic sectional view of the idle pulley assembly and the idle pulley support shown in  FIG. 42  taken along line XXXII-XXXII according to an embodiment of the present invention. 
         FIG. 44  is a schematic rear view of a belt in the driving unit shown in  FIG. 36  being caught in the belt catcher according to an embodiment of the present invention. 
         FIG. 45  is a schematic perspective view of a photosensor in the driving unit shown in  FIG. 36  mounted on the photosensor support according to an embodiment of the present invention. 
         FIG. 46  is a schematic perspective view of the belt catcher, the belt, and the photosensor according to an embodiment of the present invention. 
         FIG. 47  is a schematic exploded view of a drive printed circuit board in the driving unit shown in  FIG. 36  and the rear plate of the frame according to an embodiment of the present invention. 
         FIG. 48  is a schematic exploded view of the touch panel assembly shown in  FIG. 13  according to an embodiment of the present invention. 
         FIG. 49A  is a schematic perspective view of portions of the display device shown in  FIG. 12  to  FIG. 48  illustrating the operations of the display device according to an embodiment of the present invention. 
         FIG. 49B  is a schematic perspective view of the driving unit of the display device shown in  FIG. 12  to  FIG. 48  illustrating the operations of the driving unit according to an embodiment of the present invention. 
         FIG. 50  to  FIG. 55  are schematic front views of the shutter assembly and the driving unit in the display device shown in  FIG. 49  illustrating the operations of the display device according to an embodiment of the present invention. 
         FIG. 56  is a schematic diagram comparing a double sliding door system with a single sliding door system. 
         FIG. 57  is a schematic front view of the shutter assembly and the driving unit in the display device shown in  FIG. 49  illustrating the operations of the display device according to an embodiment of the present invention. 
         FIG. 58  and  FIG. 59  are schematic top views of a track for the sliding doors according to embodiments of the present invention. 
         FIG. 60  shows a state machine of a gaming mode in a gaming machine according to an embodiment of the present invention. 
         FIG. 61  and  FIG. 62  show an example of a normal mode game according to an embodiment of the present invention. 
         FIG. 63  shows an example of a symbol code determination table for a normal mode game according to an embodiment of the present invention. 
         FIG. 64  to  FIG. 66  show examples of control data and image data according to an embodiment of the present invention. 
         FIG. 67  shows a trigger of a bonus mode game according to an embodiment of the present invention. 
         FIG. 68  shows a trigger of a chance mode game according to an embodiment of the present invention. 
         FIG. 69  shows a start of an example of a normal mode game according to an embodiment of the present invention. 
         FIG. 70  to  FIG. 78  show examples of bonus sign rendering patterns in a normal mode game according to an embodiment of the present invention. 
         FIG. 79  shows an example of a chance sign rendering patterns in a normal mode game according to an embodiment of the present invention. 
         FIG. 80  and  FIG. 81  show examples of payout rendering patterns in a normal mode game according to an embodiment of the present invention. 
         FIG. 82  shows an example of a rendering pattern for a bonus mode game according to an embodiment of the present invention. 
         FIG. 83  shows an example of a bonus mode game according to the rendering pattern shown in  FIG. 82 . 
         FIG. 84  shows another example of a rendering pattern for a bonus mode game according to an embodiment of the present invention. 
         FIG. 85  shows an example of a bonus mode game according to the rendering pattern shown in  FIG. 84 . 
         FIG. 86  shows yet another example of a rendering pattern for a bonus mode game according to an embodiment of the present invention. 
         FIG. 87  to  FIG. 90  show examples of a bonus mode game according to the rendering pattern shown in  FIG. 86 . 
         FIG. 91  shows an example of symbol code determination tables for a bonus mode game according to an embodiment of the present invention. 
         FIG. 92  shows an example of a chance mode game according to an embodiment of the present invention. 
         FIG. 93  shows an example of symbol code determination tables for a chance mode game according to an embodiment of the present invention. 
         FIG. 94  to  FIG. 97  show examples of a chance type for bonus sign in a chance mode game according to an embodiment of the present invention. 
         FIG. 98  to  FIG. 100  show examples of a chance type for bonus probability in a chance mode game according to an embodiment of the present invention. 
         FIG. 101  and  FIG. 102  show examples of a chance type for additional benefit in a chance mode game according to an embodiment of the present invention. 
         FIG. 103  to  FIG. 105  show examples of a chance type for event in a chance mode game according to an embodiment of the present invention. 
         FIG. 106  is a flowchart of a normal mode game process according to an embodiment of the present invention. 
         FIG. 107  and  FIG. 108  are flowcharts of a normal mode game process according to another embodiment of the present invention. 
         FIG. 109  and  FIG. 110  are flowcharts of a chance mode game process according to an embodiment of the present invention. 
         FIG. 111  and  FIG. 112  are flowcharts of a chance mode game process according to another embodiment of the present invention. 
         FIG. 113  is a flowchart of a bonus mode game process according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, only certain embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
     A gaming machine and a gaming method thereof according to embodiments of the present invention are described in detail with reference to the accompanying drawings. 
     Outline for Gaming Method 
       FIG. 1  is a flowchart of a gaming method according to an embodiment of the present invention. 
     Referring to  FIG. 1 , a gaming machine executes a game (S 10 ), and randomly determines a game result of the game (S 20 ). The gaming machine includes a first display panel and a secondary display, and the secondary display includes a display panel and a door located in front of the display panel. The door is opened or closed to control an exposure of the display panel, and may include a left sliding door configured to be opened in a left direction from a center position for the door and a right sliding door configured to be opened in a right direction from the center position. 
     Next, the gaming machine selects a control data corresponding to a type of the game result among a plurality of control data for controlling the door (S 30 ). The plurality of control data correspond to a plurality of types of game results, respectively. Each control data includes at least one position data for determining a position of the door, and the at least one position data corresponds to at least one of a position data for fully closing the door, a position data for fully opening the door, or at least one position data for partially opening the door. Further, the gaming machine selects a display data corresponding to the selected control data among a plurality of display data (S 40 ). The plurality of display data correspond to the plurality of control data, respectively. 
     The gaming machine displays on the display panel an image according to the selected display data (S 50 ), and controls the door using at least one position data of the selected control data (S 60 ). Subsequently, the gaming machine displays the game result on the first display (S 70 ). In this case, the gaming machine may display the image on the display panel and control the door using the at least one position, during a period between a start of the game and a display of the game result. 
     Each display data may include at least one object image, a display position data representing a position where the object image is displayed on the display panel, and a display timing data representing a timing when the object image is displayed on the display panel. The control data may be associated with the display position data and the display timing data of the corresponding display data to expose the object image through the door. Further, each control data may further include at least one timing data to move the door to a position indicated by the position data at an appropriate timing. 
     Overall Configuration of Gaming Machine 
     A gaming machine according to embodiments of the present invention is described in detail. 
     First, a mechanical structure of a gaming machine according to embodiments of the present invention is described in detail with reference to  FIG. 2  to  FIG. 8 . 
       FIG. 2  is a schematic perspective view of a slot machine according to an embodiment of the present invention,  FIG. 3  is a schematic front view of a display window of a primary display in the slot machine shown in  FIG. 2  according to an embodiment of the present invention,  FIG. 4  and  FIG. 5  are schematic diagrams showing exemplary paylines according to an embodiment of the present invention,  FIGS. 6 and 54  are symbol code tables according to an embodiment of the present invention, and  FIG. 8  is a layout view of a control panel in the slot machine shown in  FIG. 2  according to an embodiment of the present invention. 
     Referring to  FIG. 2 , a gaming machine, for example, a slot machine 1 may include a cabinet  11 , a top box  13  disposed on the cabinet  11 , and a main door  12  disposed in front of the cabinet  11 . 
     A primary display  20  including a reel assembly  30  is provided in the main door  12 . According to an embodiment of the present embodiment, the reel assembly  30  may include five reels  31   a  to  31   e . Each of the reels  31   a  to  31   e  may include a drum (not shown) that has a peripheral surface bearing plural types of symbols. The primary display  20  further includes a reel cover  21  disposed in front of the reel assembly  30  and having a display window  22  that exposes a portion of the reels  31   a  to  31   e . The reel cover  21  is provided with a display panel  24  that may include a transparent liquid crystal display panel (not shown). The primary display  20  may further include a touch panel (not shown) for receiving touch input instruction of a game player. 
     Referring to  FIG. 3 , a given number of symbols, for example, three symbols on each of the reels  31   a  to  31   e  may be shown on the display window  22  when the reels  31   a  to  31   e  are at rest. Therefore, a symbol matrix including five columns and three rows is shown on the display window  22 , where a pair of a column and a row define a symbol block DB. 
       FIG. 3  also shows an exemplary payline PL that may be displayed on the display panel  24  and may pass through a display block DB in each column. When a combination of the symbols on the payline PL in a game satisfies a predetermined condition, a player wins the game. For example, if all the symbols in a combination are the same, the gaming machine 1 awards a prize to the player. Such a combination of the symbols that provides a win is referred to as a “winning combination.” The payline PL shown in  FIG. 3  is merely an example, and various paylines may be drawn and two or more paylines may be selected by a player. 
       FIG. 4  and  FIG. 5  show a variety of paylines PL 1 -PL 30 . An exemplary play line P 1 , P 2  or P 3  shown in  FIG. 4  connects five blocks in the second, first, or third row, respectively, and another exemplary payline P 11  shown in  FIG. 4  connects four lower blocks in the first, second, fourth, and fifth columns and a middle block in the third column. Another exemplary payline P 21  shown in  FIG. 5  connects lower blocks in the second, third, and fourth columns and middle blocks in the first and fifth columns at the second row. 
     In addition to a win with the payline PL (referred to as a “line win”), there is another type of win referred to as “scatter win” that is given when a scatter symbol among the plural types of the symbols is shown on the display window  22 . 
     Referring to  FIG. 6 , a symbol sequence including a plurality of symbols is marked on each of the reels  31   a  to  31   e . Each symbol in the symbol sequence may be assigned to a code, and may include a picture (hereinafter referred to as “a picture symbol”) or may include no picture (hereinafter referred to as “a blank symbol”). The picture symbols may include symbols denoted by, for example, “7,” “BAR,” “DOUBLE BAR,” or “TRIPLE BAR,” a scatter symbol (denoted by “BONUS”), and a specific symbol (denoted by “CHANCE”). For example, the symbol sequence may include eleven picture symbols and eleven blank symbols each being located between adjacent two picture symbols. Codes ranging from “00” to “21” may be assigned to the eleven picture symbols and the eleven blank symbols. In an example symbol code table shown in  FIG. 6 , the “BAR,” blank, “7,” blank, “TRIPLE BAR,” blank, “BONUS,” blank, “DOUBLE BAR,” blank, “TRIPLE BAR,” blank, “DOUBLE BAR,” blank, “7,” blank, “DOUBLE BAR,” blank, “BAR,” blank, “7,” and blank symbols to which the codes from “00” to “21 are respectively assigned are marked on the first reel  31   a  (reel  1 ). Further, as shown in  FIG. 6 , “CHANCE” symbol may be marked on only the third reel  31   c  (reel  3 ). A gaming machine spins the reels  31   a  to  31   e  according to a player&#39;s input, and randomly determines a code for each of the reels  31   a  to  31   e . After a certain time period elapses, the gaming machine stops each of the reels  31   a  to  31   e  to locate the symbol corresponding to the determined code at one row (for example, the middle row) of the symbol matrix. Accordingly, the symbols are rearranged in the symbol matrix. 
     In another example symbol code table shown in  FIG. 7 , “WILD” symbol is marked on each of the reels  31   a  to  31   e , instead of a predetermined symbol, for example the “7” symbol. The blank symbol adjacent to the “WILD” symbol may be substituted to the “WILD” symbol. The “WILD” symbol may establish its own winning combination, or may be substituted to a certain symbol to combine with the certain symbol of the pay line and establish the winning combination. Alternatively, the “WILD” symbol may be not marked on all of the reels  31   a  to  31   e , but be marked to only some of the reels  31   a  to  31   e.    
     The arrangement of the symbols may determine a mode of a subsequent game, the mode selected from a normal mode and a chance mode. 
     The display panel  24  on the reel cover  21  displays a betting amount, a credit amount and a payout amount in respective areas which do not overlap the symbol arrangement. The credit amount indicates the number of coins that are owned by the player and deposited inside the slot machine 1. The payout amount indicates the number of coins to be paid out to the player when a winning combination is established. 
     Although the slot machine 1 employs the mechanical reels  31   a  to  31   e  in the present embodiment, video reels or a combination of the mechanical reels and the video reels may be used as well, alternatively. 
     An IC card reader  62  is disposed below the primary display  20 . The IC card reader  62  receives an IC card which stores predetermined data such as player identification information and game log data related with the games previously played by the player. Also, the IC card may store data equivalent to coins, bills, or credits owned by the player. The IC card reader  62  reads and writes data from and to the inserted IC card. The IC card reader  62  includes an LCD for displaying the data read from the IC card. 
     In front of a lower end of the IC card reader  62  are provided a control panel  40 , on which includes various buttons, a coin entry  41 , and a bill entry  43 . For example, referring to  FIG. 8 , a RESERVE button  51 , a COLLECT button  52 , and a GAME RULES button  53  are disposed on an upper left area of the control panel  40 . 1-BET button  56   a , 2-BET button  56   b , 3-BET button  56   c , 5-BET button  56   d , and 10-BET button  56   e  are disposed on a lower left area of the control panel  40 . Also, a START button  54  is disposed on the lower center area of the control panel  40 . The coin entry  41  is disposed upper center area, and the bill entry  43  is disposed right area of the control panel  40 . 
     The RESERVE button  51  is used when the player temporarily leaves the seat or when the player wants to ask a staff of the game facility to exchange money. Alternatively, the RESERVE button  51  may be used to store remaining credits into an IC card inserted into the IC card reader  62 . The COLLECT button  52  is used to instruct the slot machine 1 to pay out credited coins to a coin tray  15 . The GAME RULES button  53  is used when the player is not acquainted with game rules or manipulation method. When the GAME RULES button  33  is pressed, various types of help information are displayed on a secondary display  70 . 
     The BET buttons  56   a  to  56   e  are used to set the betting amount. Each time the 1-BET button  56   a  is pressed, one credit is bet for each active pay line from the current credits owned by the player. When the 2-BET button  56   b  is pressed, the game is started on condition that two credits are bet for each active pay line. When the 3-BET button  56   c  is pressed, the game is started on condition that three credits are bet for each active pay line. When the 5-BET button  56   d  is pressed, the game is started on condition that five credits are bet for each active pay line. When the 10-BET button  56   e  is pressed, the game is started on condition that ten credits are bet for each active pay line. The START button  54  is used to instruct the initiation of spinning the reels  31   a  to  31   e  under the previously set betting condition. 
     The coin entry  41  receives coins and guides the inserted coins into a hopper inside the cabinet  11 . The bill entry  43  receives a bill and validates the legitimacy of the inserted bill to accept only a legitimate bill into the cabinet  11 . 
     On a lower front face of the main door  13  and below the control panel  40 , there are provided a belly glass  14  on which a character of the slot machine b  1  or the like is drawn, and a coin tray  15  receiving coins paid out from the cabinet  11 . 
     Referring back to  FIG. 2 , a secondary display  70  that may include the display device  1000  shown in  FIG. 1  to  FIG. 48  is provided at the front face of the top box  13 . The secondary display  70  may provide rendering effect for enhancing the amusement of the game, and displays information of game rules and manipulation methods. Also, a speaker  17  and a lamp  18  are provided on the side and top faces, respectively, of the top box  13 . The slot machine 1 augments the amusement of the game by providing sound effect or flashing light through the speaker  17  or the lamp  18 , respectively. 
     Below the secondary display  70 , there are provided a ticket printer  66 , a keypad  67 , and a data display  68 . 
     The ticket printer  66  prints, on a ticket, a bar code containing the credit data, date and time, and an ID number of the slot machine 1 to output the barcode imprinted ticket. The player can exchange the barcode imprinted ticket with bills or the like at a predetermined location of a gaming facility (e.g., from a casher in a casino). 
     The keypad  67  includes a plurality of keys allowing the player to input instructions pertinent to the issuance of the ticket. The data display  68 , which is implemented using a fluorescent display, LEDs, or the like, displays data input by the player through the keypad  67 . 
     Electrical Configuration of Slot Machine 
     Now, electrical structure of the slot machine 1 shown in  FIG. 2  is described in detail with reference to  FIG. 9  to  FIG. 11 . 
       FIG. 9  is an electrical block diagram of the slot machine shown in  FIG. 2  according to an embodiment of the present invention,  FIG. 10A  is a block diagram of an electrical circuit of the reel assembly according to an embodiment of the present invention,  FIG. 10B  is a block diagram of the second display according to an embodiment of the present invention, and  FIG. 11  is a functional block diagram of the game program executed by a main CPU of a motherboard in the slot machine shown in  FIG. 2  according to an embodiment of the present invention. 
     Referring to  FIG. 9 , the slot machine 1 includes a gaming board  80 , a motherboard  90 , and a door PCB  86 , and a body PCB  87 . 
     A gaming board  80  includes a CPU  81 , a ROM  82  accessible by the CPU  81  through an internal bus, and a boot ROM  83  accessible by the CPU  81  by an internal bus. The gaming board  80  additionally includes a card slot  84  which can receive and communicate with a memory card  84   s , and an IC socket  85  provided correspondingly to a Generic Array Logic (GAL)  85   s.    
     The memory card  84   s  includes a non-volatile memory and stores a game program and a game system program. 
     The card slot  84  is configured to receive and eject the memory card  84   s , and is connected to a motherboard  90  by an IDE bus. The details of the game performed in the slot machine 1 can be changed by replacing the memory card  84   s  with another one, or by withdrawing the memory card  84   s  from card slot  84 , writing another program into the memory card  84   s , and then inserting the memory card  84   s  into the card slot  84  again. 
     The GAL  85   s , which is a type of a Programmable Logic Device (PLD) having a fixed OR array structure, has a plurality of input ports and output ports. When the GAL  85   s  receives certain data through the input ports, it outputs data corresponding to the input data through the output ports. 
     The IC socket  85  is configured in such a manner that the GAL  85   s  can be inserted into the IC socket  85  or detached from the IC socket  85 , and connected to a motherboard  90  by a PCI bus. 
     The CPU  81 , the ROM  82 , and the boot ROM  83  interconnected by the internal bus are connected to the motherboard  90  by the PCI bus. The PCI bus enables signal transmission between the motherboard  90  and the gaming board  80 , and supply of power from the motherboard  90  to the gaming board  80 . 
     The ROM  82  stores an authentication program. The boot ROM  83  stores a preliminary authentication program, a boot code to be used by the CPU  81  for activating the preliminary authentication program, and the like. The authentication program is a tamper check program for authenticating the originality of the game program and the game system program. The preliminary authentication program is a program for authenticating the originality of the authentication program. The authentication program and the preliminary authentication program are written in a sequence of proving that the subject program has not been tampered. 
     The motherboard  90 , which may be implemented using a commonly available general main board, executes the game program and the game system program. The motherboard  90  includes a main CPU  91 , a ROM  92 , a RAM  93 , and a communication interface  94 . 
     The ROM  92 , which may be a flash memory, may be configured to store a program to be executed by the main CPU  91  such as BIOS, along with another data to be maintained permanently. When being executed by the main CPU  91 , the BIOS performs initialization of peripheral devices. Also, the BIOS starts to load the game program and the game system program stored in the memory card  54  through the gaming board  80 . The ROM  92  may be rewritable. However, write-protected one might be used as the ROM  92  as well. 
     The RAM  93  stores data and programs which are used during the operation of the main CPU  91 . For example, when the game program, the game system program, or the authentication program is to be loaded, the RAM  93  can store such programs. Also, the RAM  93  is provided with working space for the execution of the programs. Examples of the space include a space for storing the number of bets, the payout amount, the credit amount, and the like can be maintained during the execution of the game. Also, plurality of tables defining symbols, symbol codes, winning combinations, and their probabilities are maintained during the execution of the game. Further, the RAM  93  stores symbol code determination tables which stores mapping information between symbol codes and random number which can used for determining symbols based on random numbers. In particular, the RAM  93  maintains a mode flag indicating the gaming mode, along with a game and a game counter of which count value indicates the number of executed chance mode games or the number of possibly remaining chance mode games. 
     Also, the RAM  93  stores count values of a plurality of counters, which include a bet counter, a payout amount counter, a credit amount counter, and a chance mode game counter which counts the number of chance mode games. Alternatively, however, some of the count values can be maintained in an internal register of the main CPU  91 . 
     The communication interface  94  facilitates data communication of the main CPU  91  with an external controller of, for example, a server through a communication channel. 
     Besides, the motherboard  90  is connected to the door PCB  86  and the body PCB  87  by USB communications. The motherboard  90  is also connected to a power supply  88 . The main CPU  91  of the motherboard  90  boots up and operates using the power supplied from the power supply  88 , and passes over some of the power to the gaming board  80  through the PCI bus so as to boot up the CPU  81 . The door PCB  86  and the body PCB  87  are connected to input devices such as a switch and a sensor, and peripheral devices of which operation are controlled by the main CPU  91 . Also, the door PCB  86  is connected with a control panel  40 , a coin counter  46 , a reverter  47 , and a cold cathode tube  78 . 
     The control panel  40  has a reserve switch  51   s , a collect switch  52   s , a game rule switch  53   s , a start switch  54   s , a 1-BET switch  56   as , a 2-BET switch  56   bs , a 3-BET switch  56   cs , a 5-BET switch  56   ds , and a 10-BET switch  56   es , each of which is provided correspondingly to respective buttons  51  to  54  and  56   a  to  56   e . The switches  51   s  to  54   s  and  56  as to  56   es  detects pressing of the respective buttons  51  to  54  and  56   a  to  56   e  to output signals to the main CPU  91 . 
     The coin counter  46  and the reverter  47  are disposed in the coin entry  41 . The coin counter  46  validates legitimacy of coins inserted into the coin entry  41  in terms of material, shape, or the like. The coin counter  46  outputs a signal to the main CPU  91  when detecting a legitimate coin. Meanwhile, illegitimate coins are discharged to the coin tray  15 . The reverter  47 , which operates based upon a control signal from the main CPU  91 , distributes the legitimate coins validated by the coin counter  46  into either a hopper  16  or a cash box (not shown in the drawing). The coins are guided into the hopper  16  when the hopper  16  is not filled with coins. Contrarily, however, the coins are guided into the cash box when the hopper  16  is filled with coins. 
     The cold cathode tube  78 , which is disposed on the rear face of the secondary display  70 , functions as a backlight and illuminates based on a control signal from the main CPU  91 . 
     The body PCB  87  is connected with the speaker  17 , the lamp  18 , the hopper  16 , a coin detector  42 , the touch panel  26 , a bill validator  44 , the reel assembly  30 , the IC card reader  62 , a graphic card  76 , the ticket printer  66 , a key switch  67   s , and the data display  68 . 
     The lamp  18  flashes based upon a control signal from the main CPU  91 . The speaker  17  outputs a sound such as BGM based upon the control signal from the main CPU  91 . 
     The hopper  16 , which operates based upon a control signal from the main CPU  91 , pays out coins of the designated payout amount to the coin tray  15  through a coin payout exit formed between the belly glass  14  and the coin tray  15 . The coin detector  42  detects coins paid out from the hopper  16  to output a detection signal to the main CPU  91 . 
     The touch panel  26  detects a position touched by the player to provide the main CPU  91  with a position sense signal corresponding to the detected position. The bill validator  44  in the bill entry  43  provides, upon detection of a legitimate bill, the main CPU  91  with a bill detection signal corresponding to the bill amount. 
     The graphic card  76  controls video display of the secondary display  70  and the display panel  24  of the primary display  20  in response to a control signal from the main CPU  91 . The graphic card  76  includes a Video Display Processor (VDP) generating video data, and a video RAM temporarily storing the video data. The video data may be originated from the game program stored in the RAM  93 . 
     The IC card reader  62  reads out data stored in the IC card inserted into the card slot  176  to provide the read-out data to the main CPU  91 . Also, the IC card reader  62  writes data received the main CPU  91  into the ID card. 
     The ticket printer  66  prints on a ticket the barcode containing information of the credit amount stored in the RAM  93 , date and time, the identification number of the slot machine 1, and the like, in response to the control signal from the main CPU  91  to output the barcode imprinted ticket. 
     The key switch  67   s , which is disposed behind the keypad  67 , outputs a key detection signal to the main CPU  91  when the keypad  67  is pressed by the player. 
     The data display  68  displays information related the input through the keypad  67  in response to a control signal from the main CPU  91 . 
     The body PCB  87  is also electrically connected to the reel assembly  30 , which includes first to fifth reel units  30   a  to  30   e , each of the reel unit  30   a  to  30   e  including the reels  31   a  to  31   e , respectively. 
     Referring to  FIG. 10A , each of the reel units  30   a  to  30   e  includes a reel circuit board  36 . The reel circuit board  36  includes an input/output (I/O) unit  37  capable of communicating with the body PCB  87 , a reel driver  32   t  connected to the I/O unit  37 , a backlight driver  34   t , and a lighting unit driver  35   t.    
     To the I/O unit  37  is connected a magnetic field detector  33 , which includes a magnetic sensor for sensing magnetic field intensity to output a magnetic detection signal proportional to the magnetic field intensity, and sensor fixation means for fixing the magnetic sensor to a predetermined position. The magnetic sensor detects the intensity of the magnetic field generated by a magnet which is connected to a rotating axis of a reel motor  32  to rotate with the reel  31   a.    
     The reel driver  32   t  supplies electric power to the reel motor  32 . The backlight driver  34   t  supplies electric power individually to each light source  34   s  in a backlight unit  34 . The lighting unit driver  35   t  supplies electric power individually to each light source  35   t  of a lighting unit  35 . 
     Since a second to a fifth reel units  30   b  to  30   e  have the same configuration as a first reel unit  30   a , detailed description thereof will be omitted. 
     The body PCB  87 , which is connected to the main CPU  92 , may be also electrically connected to the secondary display  70 . Therefore, referring to  FIG. 10B , the main CPU  92  may be also connected to the secondary display  70 , particularly to the magnetic sensor  460  and the photosensors  471  and  475  of a driving unit ( 400  of below  FIG. 12 ). As described above, the magnetic sensor  460  detects the rotation of the idle pulley  431  coupled to the belt  440  and generates a magnetic sensor signal corresponding thereto. 
     The magnetic sensor  460  may include a discotic magnet  462  configured to rotate along with the idle pulley  431  and a magnetic field detection member  464  configured to detect magnetic field and to generate the magnetic sensor signal. The magnetic field detection member  464  may be disposed near a circumference of the magnet  462 , and thus the magnetic field at the position of the magnetic field detection member  464  may be different for different rotational angles of the magnet  462  and the idle pulley  431 . Therefore, different values of the magnetic sensor signal generated by the magnetic field detection member  464  may indicate different positions of the sliding door  330 . 
     According to another embodiment of the present invention, a single value of the magnetic sensor signal may indicate a few different positions of the sliding door  330  when the moving distance of the sliding door  330  is greater than the circumference of the idle pulley  431 . In this case, a counter (not shown) may be added to count the rotation number of the magnet  462  such that a combination of the rotational angle and the rotation number of the magnet  462  may have one-to-one correspondence with the position of the sliding door. 
     The information about the relation between the magnitude of the magnetic sensor signal and the position of the sliding door  330  or between a combination of the magnitude of the magnetic sensor signal and the count number and the position of the sliding door  330  may be stored as a door position table in a memory MEM. 
     The body PCB  87  and thus the main CPU may be also electrically connected to the drive printed circuit board  490  of the driving unit  400 . The main CPU  91  determines the position of the sliding door  330  based on the signal from the magnetic sensor  460 , and controls the motor  411  to move the sliding door  330  to a target position and to stop at the target position for a target duration via the motor gear  416 , the pulley gear  423 , the driving pulley  421 , and the belt  440 . 
     The shutter system of the secondary display  70  may be used in conducting a rendering effect of a game or indicating a sign for a game. For example, the second display  70  may be configured to inform that a result of a game triggers a bonus game by a predetermined expectation degree before the result of the game is displayed. 
     A plurality of patterns of moving pictures and corresponding movements of the sliding door  330  may be used in rendering effect. The information about the patterns of the moving pictures may be stored as a pattern table in the memory MEM, and the information about the movements of the sliding door  330 , for example, the positions of the sliding door  330  and resting durations of the sliding door  330  may be stored as a door control table in the memory MEM. The main CPU  92  may select one of the pattern data stored in the pattern table and one of the door control data stored in the door control table based on the result of the game. The main CPU  92  may control the display panel  210  to display images based on the selected pattern data, and may control the movement of the first sliding door based on the selected door control data. 
     The magnetic sensor  460  and the photosensors  471  and  475  may be used in checking the driving unit  400 . 
     There are a plurality of types of errors of the driving unit  400 , which may be detectable by using the magnetic sensor  460  and the photosensors  451  and  457 . Hereinafter, the photosensor  471  near the driving pulley  421  is referred to as “an origin sensor,” and the photosensor  475  near the idle pulley  431  is referred to as “an limit sensor.” For example, when the motor  411  does not operate, the sliding door  430  does not move, or the belt  440  is loosened to be taken away, it may be detected by the magnetic sensor  460  and/or the limit sensor  475 . In addition, the magnetic sensor  460  and/or the limit sensor  475  also may detect whether the sliding door  431  does not reach its target position, and whether the sliding door  430  is separated from the belt  440 . 
     When initializing the driving unit  400 , first, the sliding door  430  is fully closed. If the origin sensor  471  turns off, it is determined that it is in a normal state. However, if the origin sensor  471  turns on, it is determined that there is a defect in the origin sensor  471 . On the other hand, it is determined that the limit sensor  475  is in a normal state if it turns on, but it is determined that the limit sensor  475  is in an abnormal state if it turns off. The magnetic sensor  460  may be determined to be normal if the value of the magnetic sensor signal varies. When the value of the magnetic sensor signal does not vary, the magnetic sensor  460  is normal if the limit sensor  475  turns on at the beginning, while the magnetic sensor  460  is abnormal otherwise. If it is determined that there are errors in both the limit sensor  475  and the magnetic sensor  460 , there may be an error in the moor  411 . 
     Next, the sliding door  430  is fully opened, and then the error detection condition may be opposite to the previous case. That is, the origin sensor  471  is determined to be normal when it turns on, but abnormal if the origin sensor  471  turns off. On the other hand, the limit sensor  475  is determined to be normal if it turns off, but abnormal if it turns on. The magnetic sensor  460  may be determined to be normal if the detected position of the sliding door  330  is not far from the motor  411 . When the value of the magnetic sensor signal does not vary, the magnetic sensor  460  is normal if the limit sensor  475  turns on at the beginning, while the magnetic sensor  460  is abnormal otherwise. If it is determined that there are errors in both the origin sensor  471  and the magnetic sensor  460 , there may be an error in the moor  411 . 
     During a normal operation of the driving unit  400 , the sliding door  430  is fully closed. If the origin sensor  471  turns off, it is determined that it is in a normal state. However, if the origin sensor  471  turns on, it is determined that there is a defect in the origin sensor  471 . On the other hand, it is determined that the limit sensor  475  is in a normal state if it turns on, but it is determined that the limit sensor  475  is in an abnormal state if it turns off. When the sliding door  430  is fully opened, the origin sensor  471  is determined to be normal when it turns on, but abnormal if the origin sensor  471  turns off, and the limit sensor  475  is determined to be normal if it turns off, but abnormal if it turns on. At this time, the magnetic sensor  460  may be determined to be abnormal if the detected position of the sliding door  330  is far from the motor  411 . 
     When the power is supplied to the slot machine 1, the main CPU  91  reads the authenticated game program and game system program from the memory card  84   s  through the gaming board  80  and writes the programs into the RAM  93 . The game program is executed in a state being loaded into the RAM  93  in such a manner. 
     According to an embodiment, as shown in  FIG. 11 , the game program includes a input/bet check  91   a , a random number generation  91   b , a symbol determination  91   c , a game counter  91   d , a reel control  91   e , a win determination  91   f , a rendering control  91   g , a payout  91   h , and a game mode determination  91   i  to execute respective processing. 
     The bet/input check  91   a , in an idle state where the reels  31   a  to  31   e  stop, continuously checks whether any of the BET buttons  56   a  to  56   e  or the START button  79  is pressed. After the BET buttons  56   a  to  56   e  or the START button  79  is pressed, the bet/input check  91   a  checks whether there remains any credit for the player on the basis of credit data  93   a  stored in the RAM  93 . If the player has at least one remaining credit, the bet/input check  91   a  call the random number generation  91   b.    
     Subsequently, the random number generation  91   b  generates random numbers to be used for the symbol determination  91   c . In the present embodiment, the random number generation  91   b  generates five random numbers, each of which is directed to respective one of the first though the fifth reel units  30   a  to  30   e.    
     After five random numbers are completely extracted, the symbol determination  91   c  determines a to-be-stopped symbol for each of the reel units  30   a  to  30   e  with reference to the symbol code determination table stored in the RAM  93 . The symbol determination  91   c  uses the five random numbers to determine five to-be-stopped symbols for the reel units  30   a  to  30   e  to be shown in the display window  22  of the primary display  20  for each of the reels  31   a  to  31   e.    
     In particular, the symbol determination  91   c  checks the current gaming mode with reference to mode flag  93   b  stored in the RAM  93 , and differentiates the symbol determination process between the normal mode and the chance mode. In the normal mode, the symbol determination  91   c  applies a fixed symbol code determination table to determine the symbol using the random number according to a fixed scheme. Contrarily, however, the symbol determination  91   c  consecutively changes the symbol code determination table for each unit game to vary the symbol determination process. The consequence of varying the symbol code determination table is that winning combinations including at least one specific symbol increases as the chance mode games continue. Possible number of chance mode games available in a single session is limited to a certain limit, e.g., eight. In order to limit the number of chance mode games, a game counter  91   d  counts the number of chance mode games already performed or possibly remaining in the session, and a game count value  93   c  is stored in the RAM  93 . The game counter  91   d  may reside in the symbol determination  91   c , alternatively. 
     The reel control  91   e  provides controls the reel assembly  30  by providing stop position information corresponding to the determined symbols, so that the reels  31   a  to  31   e  spins and stops at position designated by the stop position information. Thus, the symbols scrolls along with the spinning of the reels  31   a  to  31   e  and then stops in such a manner that the determined symbols are arranged in central position vertically in the display window  22  of the primary display  20 . 
     Meanwhile, the win determination  91   f  determines whether any winning combination is established in the rearranged symbols. In case that a winning combination is established in the rearranged symbols, the rendering control  91   g  controls the primary display  20  and the other devices such as the speaker  17 , the lamp  18 , the secondary display  70  to output production effect. The production effect includes video and audio effect, backlight change, and lighting effect. Also, the payout  91   h  determines payout amount depending on the established winning combination to payout the amount the player obtained. 
     Meanwhile, whenever the unit game is completed, the game mode determination  91   i  determines the gaming mode of the next unit game. The game mode determination  91   i  changes the normal mode into the chance mode when a trigger event occurs in the rearranged symbols. On the other hands, the game mode determination  91   i  changes the chance mode into the normal mode when an exit condition is satisfied. In the other cases, the game mode determination  91   i  maintains the previous gaming mode. Meanwhile, the game mode determination  91   i  can be implemented inside win determination  91   f.    
     Outline of Display Device for Gaming Machine 
     A display device for a gaming machine according to embodiments of the present invention is described with reference to  FIG. 12  and  FIG. 13 . 
       FIG. 12  is a schematic perspective view of a display device for a gaming machine according to an embodiment of the present invention, and  FIG. 13  is a schematic exploded view of the display device shown in  FIG. 12 . 
     Referring to  FIG. 12  and  FIG. 13 , a display device  1000  for a gaming machine according to embodiments of the present invention includes a frame  100 , a display panel assembly  200 , a shutter assembly  300 , a driving unit  400 , and a touch panel assembly  500 . 
     The shutter assembly  300  may be disposed in front of the display panel assembly  200 , and may be driven by the driving unit  400  to selectively cover the display panel assembly  200 . The frame  100  may support the display panel assembly  200 , the shutter assembly  300 , the driving unit  400 , and the touch panel assembly  500 . For example, the frame  100  may form a space  190  therein so that the display panel assembly  200  may be received in the space  190  of the frame  100 . 
     The display device  1000  may have a rough bilateral symmetry, but embodiments of the present invention are not limited thereto. 
     The display device  1000  may be coupled to a gaming machine (not shown). For example, the display device  1000  may be used as a secondary display of a gaming machine. 
     Now, exemplary structures of the frame  100 , the display panel assembly  200 , the shutter assembly  300 , and the driving unit  400  are described with reference to corresponding figures. 
     Frame 
     First, the frame  100  according to embodiments of the present invention is described in detail with reference to  FIG. 14  to  FIG. 24 . 
       FIG. 14  is a schematic perspective view of the frame shown in  FIG. 12  and  FIG. 13  according to an embodiment of the present invention,  FIG. 15  is a schematic exploded view of the frame shown in  FIG. 14 ,  FIG. 16  is a schematic perspective view of parts of the frame and the display panel assembly,  FIG. 17  and  FIG. 18  are schematic perspective views of a base assembly of the frame shown in  FIG. 14  according to an embodiment of the present invention,  FIG. 19  is a sectional view of the base assembly shown in  FIG. 17  and  FIG. 18  taken along line VIII-VIII,  FIG. 20  is a schematic perspective view of a right column of the frame shown in  FIG. 14  according to an embodiment of the present invention,  FIG. 21  is a schematic perspective view of a rear plate of the frame shown in  FIG. 14  according to an embodiment of the present invention,  FIG. 22  is a schematic perspective view of a top assembly of the frame shown in  FIG. 14  according to an embodiment of the present invention,  FIG. 23  is a schematic perspective view of a top plate of the top assembly shown in  FIG. 22  according to an embodiment of the present invention, and  FIG. 24  is a schematic rear perspective view of idle pulley supports and magnetic sensor supports of the top plate of the top assembly shown in  FIG. 22  according to an embodiment of the present invention. 
     Referring to  FIG. 14  and  FIG. 15 , the frame  100  according to embodiments of the present invention may include a base assembly  110 , a right column  120 , a left column  140 , a rear plate  150 , a top assembly  160 , and a cover plate  180 . The frame  100  according to embodiments of the present invention may have a bilateral symmetry. For example, the right column  120  and the left column  140  may be bilaterally symmetrical, and each of the base assembly  110 , the rear plate  150 , the top assembly  160 , and the cover plate  180  may have a bilateral symmetry by itself. However, embodiments of the present invention are not limited thereto. 
     The right column  120 , the left column  140 , and the rear plate  150  may be coupled to the base assembly  110 . The top assembly  160  may be coupled to the right column  120  and the left column  140 , and the cover plate  180  may be coupled to the top assembly  160 . The base assembly  110 , the right column  120 , the left column  140 , the rear plate  150 , and the top assembly  160  may form the space  190  configured to receive the display panel assembly  200 , and  FIG. 16  shows the display panel assembly  200  received in the space  190  of the frame  100 . 
     Referring to  FIG. 17  to  FIG. 19 , the base assembly  110  according to embodiments of the present invention may include a base plate  111 , a first support  116 , a second support  117 , and a threshold  118 . The first support  116 , the second support  117 , and the threshold  118  may be fixed to the base plate  111 . 
     The base plate  111  may include a horizontal portion  112  and a plurality of vertical portions  113 ,  114  and  115  connected to the horizontal portion  112 . The horizontal portion  112  may have a flat surface, and may have a shape of a rectangle that has a pair of transverse edges and a pair of longitudinal edges shorter than the transverse edges. The vertical portions  113 ,  114  and  115  may be connected to respective edges of the horizontal portion  112 , and may have rectilinear or curved bottom edges. For example, a front vertical portion  113  may be connected to a front edge of the horizontal portion  112 , and a rear vertical portion  115  may be connected to a rear edge of the horizontal portion  112 , while a pair of lateral vertical portions  114  may be connected to lateral edges of the horizontal portion  112 . The vertical portions  113 ,  114  and  115  may serve as supports for the horizontal portion  112 , and the front vertical portion  113  may be coupled with the right column  120  and the left column  140 . 
     The first support  116  and the second support  117  may be coupled to or fixed to a bottom surface of the horizontal portion  112  of the base plate  111 , and may extend along a longitudinal direction. The first support  116  may be folded twice to include a horizontal portion, a vertical portion, and an inclined portion connected in series. The horizontal portion of the first support  116  may face the bottom surface of the horizontal portion  112  of the base plate  111 , and may be fixed thereto. At least a part of the vertical portion and the inclined portion of the first support  116  may project below the vertical portions  113 ,  114  and  115  of the base plate  111 . The second support  117  may be disposed in front of the first support  116 , and may be folded once to have a horizontal portion and a vertical portion connected to the horizontal portion. The horizontal portion of the second support  117  may face the bottom surface of the horizontal portion  112  of the base plate  111 , and may be fixed thereto. 
     A bottom edge of the first support  116  may be disposed lower than a bottom edge of the second support  117  and the bottom edges of the base plate  111 , and the horizontal portion  112  of the base plate  111  and thus the display device  1000  disposed thereon may become inclined frontward when the display device  1000  is placed on a horizontal surface. 
     The threshold  118  may be coupled to or fixed to a top surface of the horizontal portion  112  of the base plate  111 , and may extend in the longitudinal direction. The threshold  118  may be folded once to have a horizontal portion and a vertical portion connected thereto. The horizontal portion of the threshold  118  may face the top surface of the horizontal portion  112  of the base plate  111 , and may be fixed thereto. The vertical portion of the threshold  118  may project upward so that the threshold  118  may be configured to set a front boundary of the space  190  of the frame  100 , which receives the display panel assembly  200 , as shown in  FIG. 16 . 
     The right column  120  and the left column  140  may be affixed to the base plate  111  of the base assembly  110 , and may include supports for the display device assembly  300 , the driving unit  400 , the touch panel assembly  500 , and the top assembly  160 . 
     Referring to  FIG. 20 , the right column  120  according to embodiments of the present invention may include a front plate  130 , a rear plate  121 , an inner plate  127 , and an outer plate  128 . The front plate  121  and the rear plate  125  facing each other may be fixed to the inner plate  127  and the outer plate  128  facing each other. 
     The front plate  130  may include an upper portion  131  and a lower portion  135  connected to the upper portion  131 . The upper portion  131  of the front plate  131  may stand vertically, and may be rectangular. The upper portion  131  may be coupled to the shutter assembly  300 , and may have a plurality of holes, for example, four rectangular holes  132  disposed near corners thereof. The lower portion  135  may project frontward from a lower edge of the upper portion  131 , and may be folded at least once, for example, three times. The lower portion  135  may include a shutter support  136  configured to support the shutter assembly  300 , and may further include a touch panel support  137  configured to support the touch panel assembly  500 . The lower portion  135  may further include coupling members, for example, a first vertical surface  138  configured to be coupled to the touch panel assembly  500  and a second vertical surface  139  configured to be coupled to the base plate  111  of the base assembly  110 . The second vertical surface  139  of the front plate  130  of the right column  120  and the front vertical portion  113  of the base plate  111  of the base assembly  110  may be affixed together by fasteners, for example, flat head screws, but embodiments of the present invention are not limited thereto. 
     Referring to  FIG. 20  and  FIG. 16 , an inner edge of the lower portion  135  of the front plate  130  may project inwards from an inner edge of the upper portion  131  so that the lower portion  135  may fence the display panel assembly  200  placed in the space  190  of the frame  100 . 
     The rear plate  121  may stand vertically, and may include a coupling member  122  configured to be coupled with the base plate  111  of the base assembly  110 . The coupling member  124  may be, for example, a horizontal extension protruding rearwards, and may be affixed to the horizontal portion  112  of the base plate  111  of the base assembly  110  by fasteners, for example, screws, but embodiments of the present invention are not limited thereto. The rear plate  121  may support at least a portion of the driving unit  400 . For example, the rear plate  121  may have a central supporting hole  123  and a plurality of peripheral supporting holes  124  surrounding the central supporting hole  123  near an upper edge thereof. The central supporting hole  123  may be circular and much larger than the peripheral supporting holes  124  that may have a shape of a round rectangle. However, the shapes and the sizes of the central supporting hole  123  and the peripheral supporting holes  124  may not be limited thereto. 
     The inner plate  127  and the outer plate  128  may stand vertically. The inner plate  127  may be coupled with the rear plate  150 . The outer plate  128  may include a coupling member  129  configured to be coupled with the top assembly  160 . The coupling member  124  may be, for example, a small horizontal extension protruding inwards. 
     The left column  140  may have a structure having a substantially bilateral symmetry with the right column  120 , and thus detailed description thereof is omitted. 
     The rear plate  150  of the frame  100  may be affixed to the base plate  111  of the base assembly  110  and to the inner plate  127  of the right column  120  as well as an inner plate of the left column  140 . The rear plate  150  may also support portions of the driving unit  400 . 
     Referring to  FIG. 21 , the rear plate  150  may have a shape of a rectangular box without a lid, which stands laterally so that a bottom surface of the box may face frontwards. The rear plate  150  may include a front portion  151 , a bottom portion  156 , a top portion  157 , and a pair of later portions  158 . The front portion  151  may stand vertically, and may have a plurality of through holes  152 ,  153  and  154 . The through holes  152 ,  153  and  154  may include a pair of upper through holes  152  and  153  and a lower through hole  154 , and each of the through holes  152 ,  153  and  154  may be nearly rectangular. The bottom portion  156  and the top portion  157  may be laid horizontal, and the bottom portion  156  may be fixed to the horizontal portion  112  of the base plate  111  of the base assembly  110 . The pair of lateral portions  158  may stand vertically, and may be fixed to the inner plate  127  of the right column  120  as well as the inner plate of the left column  140 . 
     The top assembly  160  may include supports for the driving unit  400  and the cover plate  180 , and may be affixed to the outer plate  128  of the right column  120  as well as an outer plate of the left column  140 . 
     Referring to  FIG. 22 , the top assembly  160  may include a top plate  170 , and a plurality of pairs of supports  161 ,  163 ,  165 ,  167  and  168  and a pair of cover plates  169  coupled to or fixed to the top plate  170 . 
     Referring to  FIG. 22  and  FIG. 23 , the top plate  170  may include a flat horizontal portion  171 , a front portion  173 , an inner rear portion  175 , and a pair of outer rear portions  178 . The horizontal portion  171  may extend in the longitudinal direction, and may be coupled to the coupling member  129  of the right column  120  as well as a coupling member of the left column  140  near its ends. The horizontal portion  171  may include an extension  172  that may protrude rearwards. The front portion  173  may be folded upward from a substantially rectilinear front edge of the horizontal portion  171 . The inner rear portion  175  may be folded upward from a rear edge of the extension  172  of the horizontal portion  171 , and may be bifurcated into a pair of branches that may be folded frontwards to form a pair of coupling portions  176  configured to be coupled to the cover plate  180 . The pair of outer front portions  178  may be folded upward from remaining portions of the rear edge of the horizontal portion  171 . 
     Referring to  FIG. 22 , the plurality of pairs of supports  161 ,  163 ,  165 ,  167  and  168  may include two pairs of pulley supports  161  and  163 , a pair of magnetic sensor supports  165 , and two pairs of photosensor supports  167  and  168 . A pair of pulley supports  161  and  163 , a magnetic sensor support  165 , and a pair of photosensor supports  167  and  168  may be disposed left to a center of the top plate  170 , and the other pair of pulley supports  161  and  163 , the other magnetic sensor support  165 , and the other pair of photosensor supports  167  and  168  may be disposed right to the center of the top plate  170  substantially in a bilaterally symmetrical manner. 
     Each pair of the two pairs of pulley supports  161  and  163  may include a driving pulley support  161  and an idle pulley support  163 . The driving pulley support  161  may be disposed near an end of the horizontal portion  171  of the top plate  170 , and may be affixed to the horizontal portion  171 . The driving pulley support  161  may include four vertical walls, for example, a front wall, a rear wall, an inner wall, and an outer wall. The front wall and the rear wall of the driving pulley support  161  may have concentric circular through holes  162  configured to support a pulley assembly (not shown). The idle pulley support  163  may be disposed near the center of the horizontal portion  171  of the top plate  170 , and may be affixed to the horizontal portion  171 . The idle pulley support  163  may also include four vertical walls, for example, a front wall, a rear wall, an inner wall, and an outer wall. The front wall and the rear wall of the idle pulley support  163  may have concentric circular through holes  164  configured to support another pulley assembly (not shown). The idle pulley supports  163  of left and right pairs of the pulley supports  163  may form a single structure that a pair of brackets are placed laterally on a structure resembling a desk bookshelf or a file holder. 
     Referring to  FIG. 22  and  FIG. 24 , each of the pair of magnetic sensor supports  165  may be coupled to the rear wall of a corresponding idle pulley support  163 . The magnetic sensor support  165  may include a bracket that may have a circular through hole  166  configured to support a magnetic sensor (not shown). The through hole  166  of the magnetic sensor support  165  may concentric with the through holes  164  of the corresponding idle pulley support  163 , and may be smaller than the through holes  164  of the corresponding idle pulley support  163 . 
     Referring to  FIG. 22 , each of the two pairs of photosensor supports  167  and  168  may be affixed to the horizontal portion  171  of the top plate  170 , and may include a bracket. Each pair of the two pairs of photosensor supports  167  and  168  may include an outer photosensor support  167  and an inner photosensor support  168 . The outer photosensor support  167  may be disposed adjacent to a corresponding driving pulley support  161 , and may be located closer to the center of the top plate  170  than the corresponding driving pulley support  161 . The inner photosensor support  168  may be disposed adjacent to a corresponding idle pulley support  163 , and may be located closer to the center of the top plate  170  than the corresponding idle pulley support  163 . 
     Each of the pair of cover plates  169  may be affixed to the horizontal portion  171  of the top plate  170 , and may be disposed between a corresponding pair of the outer photosensor support  167  and the inner photosensor support  168 . The cover plate  169  may be folded three times such that a portion of the cover plate  169  protrudes frontwards from the top plate  170 . 
     Display Panel Assembly 
     Next, the display panel assembly  200  according to embodiments of the present invention is described in detail with reference to  FIG. 25 . 
       FIG. 25  is a schematic exploded view of the display panel assembly according to an embodiment of the present invention. 
     Referring to  FIG. 25 , the display panel assembly may include a display panel  210 , a main bracket  220 , a subsidiary bracket  230 , and a cover  240 . 
     The display panel  210  may include a flat panel display, for example, a liquid crystal display (LCD), an organic light emitting display (OLED), a plasma display panel (PDP), and so on. However, embodiments are not limited thereto. 
     The main bracket  220  may receive the display panel  210 , and may have a large center hole  222  and a plurality of heat dissipations  224 . The center hole  222  may receive the subsidiary bracket  230 . The plurality of heat dissipations  224  may be configured to dissipate heat generated by the display panel  210 , and may be located under the center hole  222 . The subsidiary bracket  230  may fit the center hole  222  of the main bracket  220 , and may have a plurality of holes  232  through which cables for the display panel  210  may pass. 
     The cover  240  may cover and protect the display panel  210 , the main bracket  220 , and the subsidiary bracket  230 . 
     Shutter Assembly 
     Next, the shutter assembly  300  according to embodiments of the present invention is described in detail with reference to  FIG. 26  to  FIG. 35 . 
       FIG. 26  is a schematic perspective view of the shutter assembly the shutter assembly  300  according to an embodiment of the present invention,  FIG. 27  is a schematic exploded view of parts of the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention,  FIG. 28  is a sectional view of a upper track of the shutter assembly shown in  FIG. 26  taken along line XVII-XVII,  FIG. 29  is a rear view of an extension of the upper track of the shutter assembly shown in  FIG. 26 ,  FIG. 30  is a schematic perspective view of a right connecting plate of the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention,  FIG. 31  is a schematic partially-exploded view of a right inner sliding door and a belt catcher in the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention,  FIG. 32  is a schematic exploded view of parts of the right inner sliding door and the belt catcher shown in  FIG. 31  according to an embodiment of the present invention,  FIG. 33  is a schematic perspective view of the belt catcher shown in  FIG. 32  according to an embodiment of the present invention,  FIG. 34  is a schematic rear perspective view of the belt catcher shown in  FIG. 33  according to an embodiment of the present invention, and  FIG. 35  is a schematic partially-exploded view of a right outer sliding door in the shutter assembly shown in  FIG. 26  according to an embodiment of the present invention. 
     Referring to  FIG. 26 , the shutter assembly  300  according to embodiments of the present invention may include a pair of tracks  310  and  320 , two pairs of sliding doors  330 ,  350 ,  360  and  370 , a pair of belt catchers  381  and  389 , a pair of connecting plates  391  and  394 , and a pair of stoppers  397  and  398 . The shutter assembly  300  may be coupled to or fixed to the right column  120  and the left column  140 . The shutter assembly  300  according to embodiments of the present invention may have a bilateral symmetry except for the positions of movable elements such as the two pairs of sliding doors  330 ,  350 ,  360  and  370  and the pair of belt catchers  381  and  389 . For example, the two pairs of sliding doors  330 ,  350 ,  360  and  370  may include a right pair of sliding doors  330  and  350  and a left pair of sliding doors  360  and  370  that may be bilaterally symmetrical to the right pair of sliding doors  330  and  350  when ignoring their positions. Similarly, the pair of connecting plates  391  and  394  may include a right connecting plate  391  and a left connecting plate  394  that may be bilaterally symmetrical to the right connecting plate  391 . Each of pair of tracks  310  and  320  may have a bilateral symmetry by itself. However, embodiments of the present invention are not limited thereto. For example, the shutter assembly  300  may include only a pair of sliding doors, for example, a right pair of sliding doors  330  and  350 , and correspondingly, a belt catcher  381 . 
     Referring to  FIG. 27 , the pair of tracks  310  and  320  may include an upper track  310  and a lower track  320  that may face each other. The upper track  310  and the lower track  320  may be connected by the right connecting plate  391  and the left connecting plate  394 , and to be coupled to the right column  120  and the left column  140  of the frame  100  along with the right connecting plate  391  and the left connecting plate  394 . The pair of stoppers  397  and  398  may include an upper stopper  397  for the upper track  310  and a lower stopper  398  for the lower track  320 . 
     Referring to  FIG. 27  and  FIG. 28 , the upper track  310  may include a pair of guide channels, for example, a front guide channel  311  and a rear guide channel  312  that are configured to guide the sliding doors  330 ,  350 ,  360  and  370 . The front guide channel  311  and the rear guide channel  312  may be formed by a plurality of elongated walls, for example, a front wall, an intermediate wall, a rear wall, and top walls. The front wall may have a stopper hole  316  near its center, and the upper stopper  397  may be fixed to the intermediate wall through the stopper hole  316  by a fastener, for example, a flat head screw FH 1 . The top wall of the front guide channel  311  has a pair of trenches  314  elongated along the front guide channel  311 , which allow the belt catchers  381  and  389  to be coupled to the sliding doors  330  and  360 . 
     The upper track  310  may further include a pair of extensions  317  that may extend downward near both ends of the upper track  310 . The pair of extensions  317  may be fixed to the right column  120  and the left column  140  of the frame  100 . For example, a right one of the extensions  317  may be affixed to the front plate  130  of the right column  120  along with the right connecting plate  391  by a fastener, for example, by a bolt and a nut. Referring to  FIGS. 28 and 18 , the extension  317  may include a front protrusion  318  and a pair of rear protrusions  319 . The front protrusion  318  may be configured to obstruct the sliding doors  350  and  370  from getting out of limited ranges in the rear guide channel  312 , and may extend horizontally in a transverse direction. The pair of rear protrusions  319  may be received in the holes  132  of the front plate  130  of the right column  120  when the upper track  310  and the right column  120  are affixed together. 
     Referring to  FIG. 27 , the lower track  330  may have structure similar to the upper track  310 . In detail, the lower track  330  may include a pair of guide channels, for example, a front guide channel  321  and a rear guide channel  322  that may be aligned with the front guide channel  311  and the rear guide channel  312 , respectively, so that they are configured to guide the sliding doors  330 ,  350 ,  360  and  370 . The lower stopper  398  may be fixed to a center of the front guide channel  321  through a stopper hole  326  by a fastener, for example, a flat head screw FH 2 . The lower track  330  may further include a pair of extensions  327  that may extend upward near both ends of the lower track  330 , and may be fixed to the right column  120  and the left column  140  of the frame  100 . 
     However, the lower track  330  may have no trench. 
     Referring to  FIG. 30 , the right connecting plate  391  may include a pair of thresholds, for example, an inner threshold  392  and an outer threshold  393  that may obstruct the sliding door  350  from getting out of limited ranges in the rear guide channel  312 . The left connecting plate  394  may also include a pair of thresholds that may obstruct the sliding door  370  from getting out of limited ranges in the rear guide channel  312 . The right connecting plate  391  and the left connecting plate  394  may be fixed to the extensions  317  and  327  by fasteners, for example, a plurality of flat head screws FH 3  and FH 4 . 
     Referring to  FIG. 26  again, each pair of sliding doors  330  and  350  or  360  and  370  may include a inner sliding door  330  or  360  and a rear door  350  or  370 . For example, the right pair of sliding doors  330  and  350  may include a right inner sliding door  330  and a right rear door  350 , and the left pair of sliding doors  360  and  370  may include a left inner sliding door  360  and a left rear door  370 . The inner sliding doors  330  and  360  may be guided by the front channels  311  and  321  of the upper and lower tracks  310  and  320 , while the outer sliding doors  350  and  370  may be guided by the rear channels  312  and  322  of the upper and lower tracks  310  and  320 . According to another embodiment, the inner sliding doors  330  and  360  may be guided by the rear channels  312  and  322 , and the outer sliding doors  350  and  370  may be guided by the front channels  311  and  321 . 
     Referring to  FIG. 31 , each of the inner sliding doors  330  and  360 , for example, the right inner sliding door  330  may include a door frame  340  and a door cover  335 . The right inner sliding door  330  may further include a pair of cushioning members  331  and  332  and four pairs of rollers  333  and  334  that are coupled to the door frame  340 . 
     The door cover  335  may be attached in front of the door frame  340 , and may have a pattern or unevenness related to a game. The pattern on the door cover  335  of the right inner sliding door  330  may be continuous to a pattern on a door cover of the left inner sliding door  360 . Furthermore, the door cover  335  may have a complete hole  336  and/or an incomplete hole  337  that may allow a game player to see a portion of a game image shown in the display panel  210 . The incomplete hole  137  may be located adjacent to an inner edge of the door cover  335 , and may form a complete hole along with another incomplete hole of the left front door  360 . 
     Referring to  FIG. 32 , the door frame  340  may include a top bar  341 , a bottom bar  343 , an outer bar  344 , a pair of inner bars  345  and  347 , and a plurality of intermediate bars  349 . The door frame  340  may not overlap the holes  336  and  337  of the door cover  335 . 
     The top bar  341  and the bottom bar  343  may face each other, and the door cover  335  may be fixed to the top bar  341  and the bottom bar  343 . The belt catcher  381  may be fixed to the top bar  341  near a center of the top bar  341  by fasteners, for example, a pair of flat head screws FH 5 . The top bar  342  may have a depression  342  on its rear surface, configured to receive the belt catcher  381 . 
     The outer bar  344  and the pair of inner bars  345  and  347  may face each other, and may be connected to the top bar  341  and the bottom bar  343 . The pair of inner bars  345  and  347  may include an upper inner bar  345  and a lower inner bar  347  aligned in a vertical direction. The inner bars  345  and  347  may protrude rearwards to form protrusions, and the inner bars  345  and  347  will be also referred to as catching protrusions hereinafter. The pair of cushioning members  331  and  332  may be attached to right (or inner) surfaces of the catching protrusions  345  and  347 . The catching protrusions  345  and  347  may have depressions  346  and  347  on the right surfaces thereof, which may receive the cushioning members  331  and  332 . 
     The plurality of intermediate bars  349  may be connected between the inner bars  345  and  347  and the outer bar  344  and between inner bars  349 . 
     Each pair of the plurality of pairs of rollers  333  and  334  may be coupled to the top bar  341  or the bottom bar  343  near an end thereof. Each pair of the rollers  333  and  334  may include a horizontal roller  333  and a vertical roller  334 . The horizontal roller  333  may have a horizontal shaft fixed to the top bar  341  or the bottom bar  343 , and the vertical roller  334  may have a vertical shaft fixed to the top bar  341  or the bottom bar  343 . The horizontal roller  333  may be closer to a corner of the door frame  340  than the vertical roller  334 . 
     Referring to  FIG. 33  and  FIG. 34 , the belt catcher  381  may include a pair of lower and upper protrusions  382  and  383  that may protrude rearwards to define a recess  385  configured to catch a belt (not shown) for power transmission. The upper protrusion  383  may have teeth  384  configured to clamp the belt. The belt catcher  381  may further include a detection piece  386  that may protrude rearwards to define a space  387  along with the upper protrusion  383 . The belt catcher  381  may further include a vertical extension  388  configured to be coupled to the top bar  341  of the door frame  340 , and the vertical extension  388  may include an elongated horizontal protrusion  389  configured to be disposed on a top surface of the top bar  341  as a threshold in the vertical direction when the belt catcher  381  is coupled to the top bar  341 . 
     Referring to  FIG. 35 , each of the outer sliding doors  350  and  370 , for example, the right outer sliding door  350  may include a door frame  351  and a door cover  358 . The right outer sliding door  350  may further include a pair of cushioning members  355  and four pairs of rollers  356  and  357  that are coupled to the door frame  351 . 
     The door cover  358  may be attached in front of the door frame  351 , and may have a pattern or unevenness related to a game. The pattern on the door cover  358  of the right outer sliding door  350  may be continuous to the pattern on the door cover  335  of the right inner sliding door  330  so that the patterns on the door covers  335  and  358  of the doors  330 ,  350 ,  360  and  370  may form a large single pattern. Furthermore, the door cover  358  may have a hole  359  that may allow a game player to see a portion of a game image shown in the display panel  210 . The height of the hole  359  of the door outer sliding door  350  may be different from the holes  336  and  337  of the inner sliding door  330 . Therefore, the hole  359  of the outer sliding door  350  may not overlap the holes  336  and  337  of the inner sliding door  330  when the inner sliding door  330  and the outer sliding door  350  overlap each other. 
     The door frame  351  may include a top bar  352   t , a bottom bar  352   b , an outer bar  352   o , and an inner bar  352   i . The top bar  352   t  and the bottom bar  352   b  may face each other, and the door cover  358  may be fixed to the top bar  352   t  and the bottom bar  352   b . The outer bar  352   o  and the inner bar  352   i  may face each other, and may be connected to the top bar  352   t  and the bottom bar  352   b . The inner bar  352   i  may include a pair of catching protrusions  354  protruding frontwards, and the pair of cushioning members  355  may be attached to right (or inner) surfaces of the catching protrusions  354 . 
     The catching protrusions  354  of the right outer sliding door  350  may overlap the catching protrusions  345  and  347  or the outer bar  344  of the right inner sliding door  330  so that the right outer sliding door  350  may follow the right inner sliding door  330  when the right inner sliding door  330  moves along the guide channels  311 ,  312 ,  321  and  322  of the tracks  310  and  320  after the right inner sliding door  330  and the right outer sliding door  350  are assembled in the upper track  310  and the lower track  320 . The cushioning members of the right outer sliding door  350  and the cushioning members  331  and  332  of the right inner sliding door  330  may reduce the impact generated when the catching protrusions  345  and  347  or the outer bar  344  of the right inner sliding door  330  bumps against the catching protrusions  354  of the right outer sliding door  350 . 
     When the inner sliding doors  330  and  360  may be guided by the rear channels  312  and  322 , and the outer sliding doors  350  and  370  may be guided by the front channels  311  and  321 , the protruding directions of the catching protrusions  354  of the right outer sliding door  350  and the catching protrusions  345  and  347  of the right inner sliding door  330  may be reversed. For example, the catching protrusions  345  and  347  of the right inner sliding door  330  may protrude frontwards, while the catching protrusions  354  of the right outer sliding door  350  may protrude rearwards. 
     Each pair of the plurality of pairs of rollers  356  and  357  may be coupled to the top bar  352   t  or the bottom bar  352   b  near an end thereof. Each pair of the rollers  356  and  357  may include a horizontal roller  356  and a vertical roller  357 . The horizontal roller  356  may have a horizontal shaft fixed to the top bar  352   t  or the bottom bar  352   b , and the vertical roller  357  may have a vertical shaft fixed to the top bar  352   t  or the bottom bar  352   b . The horizontal roller  356  may be closer to a corner of the door frame  351  than the vertical roller  357 . 
     Driving Unit 
     Next, the driving unit  400  according to embodiments of the present invention is described in detail with reference to  FIG. 36  to  FIG. 47 . 
       FIG. 36  is a schematic perspective view of the driving unit shown in  FIG. 13  according to an embodiment of the present invention,  FIG. 37  is a schematic exploded view of a motor assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention,  FIG. 38  is a perspective view of the motor assembly shown in  FIG. 37  fixed in the right column of the frame according to an embodiment of the present invention,  FIG. 39  is a rear exploded view of the motor assembly and the right column of the frame according to an embodiment of the present invention,  FIG. 40  is a schematic exploded view of a drive pulley assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention,  FIG. 41  is a schematic exploded view of a idle pulley assembly in the driving unit shown in  FIG. 36  according to an embodiment of the present invention,  FIG. 42  is a schematic perspective view of the idle pulley assembly shown in  FIG. 41  seated in the idle pulley support according to an embodiment of the present invention,  FIG. 43  is a schematic sectional view of the idle pulley assembly and the idle pulley support shown in  FIG. 42  taken along line XXXII-XXXII according to an embodiment of the present invention,  FIG. 44  is a schematic rear view of a belt in the driving unit shown in  FIG. 36  being caught in the belt catcher according to an embodiment of the present invention,  FIG. 45  is a schematic perspective view of a photosensor in the driving unit shown in  FIG. 36  mounted on the photosensor support according to an embodiment of the present invention,  FIG. 46  is a schematic perspective view of the belt catcher, the belt, and the photosensor according to an embodiment of the present invention, and  FIG. 47  is a schematic exploded view of a drive printed circuit board in the driving unit shown in  FIG. 36  and the rear plate of the frame according to an embodiment of the present invention. 
     Referring to  FIG. 36 , the driving unit  400  according to embodiments of the present invention may include a pair of left and right driving subunits configured to drive the left inner sliding door  360  and the right inner sliding door  330 , respectively. Since the left driving subunit may have a substantially bilateral symmetry with the right driving subunit, the description of the driving unit  400  will be made as if the left driving subunit does not exist. 
     The driving unit  400  may include a motor assembly  410 , an driving pulley assembly  420 , an idle pulley assembly  430 , a belt  440 , a magnetic sensor  460 , a pair of photosensors  471  and  475 , and a drive printed circuit board  490 . The driving pulley assembly  420  may be coupled to the motor assembly  410  to transmit power generated by the motor assembly  410  to the belt  440 . The right inner sliding door  330  which in turn is coupled to the belt  440  may be moved by the belt  440  through the belt catcher  381  coupled to the right inner sliding door  330  and the belt  440 . The idle pulley assembly  430  may be rotated by the belt  440 , and the rotation of the idle pulley assembly  430  may be detected by the magnetic sensor  460 . The pair of photosensors  471  and  475  may be configured to detect the belt catcher  381 , and thus the right inner sliding door  330 . 
     Referring to  FIG. 37  to  FIG. 39 , the motor assembly  410  may include an actuator, for example, a motor  411 . The motor  411  may be a stepping motor, but embodiments of the present invention are not limited thereto. The motor  411  may include a motor body  412  and a main shaft  413 , and may further include a locking pin  414  and a rear shaft  415 . The main shaft  413  may have a circumferential groove near its end, and the locking pin  414  may be pinned in the main shaft  413  near the motor body  412 . 
     The motor assembly  410  may further include a motor gear  416 , a motor shaft hub  417 , and an e-ring  419 , which may be coupled to the main shaft  413  of the motor  411 . The motor gear  416  and the motor shaft hub  417  may be affixed to each other by fasteners. The motor gear  416  may be a toothless gear, but embodiments of the present invention are not limited thereto. The motor shaft hub  417  may have a recess  418  that may engage with the locking pin  414  of the motor  411 , and the e-ring  419  may clamp the main shaft  413  in the circumferential groove of the main shaft  413 . The motor shaft hub  417  and the motor gear  416  may be fixed to the main shaft  413  between the locking pin  414  and the e-ring  419 . 
     Referring to  FIG. 38  and  FIG. 39 , the motor assembly  410  may be fixed to the rear plate  121  of the right column  120  by fasteners passing through the peripheral supporting holes  124  such that a rear surface of the motor body  412  faces a front surface of a front surface of the rear plate  121 . The rear shaft  415  and a surrounding portion of the rear surface of the motor assembly  410  may be exposed through the center supporting hole  123  of the rear plate  121 . 
     Referring to  FIG. 40 , the driving pulley assembly  420  may include a shaft  422  and a driving pulley  421  and a pulley gear  423  that may be fixed to the shaft  422  at respective ends of the shaft  422  by fasteners, for example, pins. The pulley gear  423  may engage with the motor gear  416  to transmit the rotational power from the motor gear  416  to the shaft  422 . The pulley gear  423  may be a toothless gear, but embodiments of the present invention are not limited thereto. The driving pulley  421  may be coupled to the belt  440 . The driving pulley assembly  420  may further include a pair of bearings  424  and  425  coupled to the shaft  422  between the driving pulley  421  and the pulley gear  423 . The shaft  422  may have a plurality of circumferential grooves in which e-rings  426 ,  427 ,  428  and  429  configured to prevent the movement of the driving pulley  421 , the pulley gear  423 , and the pair of bearings  424  and  425  along the shaft  422  may clamp the shaft  422 . 
     Referring to  FIG. 41 , the idle pulley assembly  430  may include a shaft  432  and an idle pulley  431  that may be fixed to the shaft  432  at an end of the shaft  432  by a fastener, for example, a pin. The idle pulley  431  may be coupled to the belt  440 . The idle pulley assembly  430  may further include a pair of bearings  433  and  434  coupled to the shaft  432 . The shaft  432  may have a plurality of circumferential grooves in which e-rings  435 ,  436  and  437  configured to prevent the movement of the idle pulley  431  and the pair of bearings  433  and  434  along the shaft  432  may clamp the shaft  432 . 
     The magnetic sensor or the magnetic encoder  460  may be coupled to the shaft  432  of the idle pulley assembly  430  near an end of the shaft  432  opposite the idle pulley  431 , and may detect the rotational angle of the idle pulley  431 . However, the magnetic sensor  460  may be coupled to the driving pulley assembly  420 . 
     Referring to  FIGS. 42 and 32 , the idle pulley assembly  430  and the magnetic sensor  460  may be coupled to the idle pulley support  163  of the top assembly  160  in the frame  100  so that the idle pulley support  163  may support the idle pulley assembly  430  and the magnetic sensor  460 . In detail, the bearings  433  and  434  of the idle pulley assembly  430  may be placed in the through holes  164  of the idle pulley support  163 , the shaft  432  of the idle pulley assembly  430  may pass through the through hole  166  of the magnetic sensor support  165 , and the magnetic sensor  460  may be fixed to the magnetic sensor support  165  by fasteners. Likewise, the driving pulley assembly  420  may be coupled to the driving pulley support  161  of the top assembly  160  in the frame  100 . In detail, the bearings  424  and  425  of the driving pulley assembly  420  may be seated in the through holes  162  of the driving pulley support  161  so that the driving pulley support  161  may support the driving pulley assembly  420 . 0   
     Referring to  FIG. 44  and  FIG. 34 , the belt  440  may be inserted into the recess  385  of the belt catcher  381  such that the belt  440  is clamped by the belt catcher  381 . Referring to  FIG. 36 , the pair of the photosensors  471  and  475  may include an outer photosensor  471  disposed near the driving pulley  421  and an inner photosensor  475  disposed near the idle pulley  431 . Referring to  FIG. 45 , each of the photosensors  471  and  475 , for example, the outer photosensor  471  may have a shape of a bracket including an upper branch and a lower branch. The outer photosensor  471  may include a light emitter  472  and a light receiver  473  provided in the upper branch and the lower branch, respectively. However, the positions of the light emitter  472  and the light receiver  473  may be reversed. 
     Referring to  FIG. 46 , when the belt catcher  381  approaches to the outer photosensor  471  and the detection piece  386  is interposed between the light emitter  472  and the light receiver  473 , the detection piece  386  may block the light emitted from the light emitter  472  such that the light receiver  473  does not receive the light. Then, the outer photosensor  471  may generate a signal corresponding thereto, and it may be determined from the signal that the right inner sliding door  330  is near the position of the outer photosensor  471 . 
     Referring to  FIG. 47 , the drive printed circuit board  490  may be fixed to a rear surface of the rear plate  150  of the frame  100  so that a front surface of the drive printed circuit board  490  may be exposed through the upper through hole  152  or  153 . 
     Touch Panel Assembly 
     Next, the touch panel assembly  500  according to embodiments of the present invention is described in detail with reference to  FIG. 48 . 
       FIG. 48  is a schematic exploded view of the touch panel assembly shown in  FIG. 13  according to an embodiment of the present invention. 
     Referring to  FIG. 48 , the touch panel assembly  500  may include a touch panel  510 , a control board  520 , a rear frame  530 , a front frame  540 , and a plurality of cushioning members  552  and  554 . The touch panel  510  may be placed between the rear frame  530  and the front frame  540 , and edges of the touch panel  510  may be covered by the cushioning members  552  and  554 . The control board  520  may be fixed on the rear frame  530  that may have a depression configured to receive the control board  520 . Although the control board  520  is shown to be disposed right to the touch panel  510  in  FIG. 48 , embodiments of the present invention are not limited thereto. The front frame  540  may include a plurality of pieces, for example, a top piece  542 , and a pair of lateral pieces  544  and  546 . One of the pair of lateral pieces  544  and  546 , for example, a right lateral piece  546  may include an extension  548  to fasten the control board  520 . 
     Operation of Display Device 
     Now, operations of the display device  1000  according to embodiments of the present invention is described in detail with reference to  FIG. 49A  to  FIG. 57 . 
       FIG. 49A  is a schematic perspective view of portions of the display device shown in  FIG. 12  to  FIG. 48  illustrating the operations of the display device according to an embodiment of the present invention,  FIG. 49B  is a schematic perspective view of the driving unit of the display device shown in  FIG. 12  to  FIG. 48  illustrating the operations of the driving unit according to an embodiment of the present invention,  FIG. 50  to  FIG. 55  and  FIG. 57  are schematic front views of the shutter assembly and the driving unit in the display device shown in  FIG. 49  illustrating the operations of the display device according to an embodiment of the present invention, and  FIG. 56  is a schematic diagram comparing a double sliding door system with a single sliding door system. 
     Referring to  FIG. 49A ,  FIG. 49B , and  FIG. 13 , the shutter assembly  300  according to embodiments of the present invention have a multiple sliding door structure, for example, a double sliding door structure including the inner sliding door  330  and the outer sliding door  350  that may move along the front guide channels  311  and  321  and the rear guide channels  312  and  322 , respectively, or vice versa. The inner sliding door  330  may be driven by the driving unit  400 , and the outer sliding door  350  follows the inner sliding door  330  by means of catching member(s), for example, the catching protrusions  345 ,  347  and  354 . 
     The driving unit  400  may include an actuator and a power transmission member configured to transmit the driving force from the actuator to the inner sliding door  330 . The driving force from the actuator, i.e., the motor  411 , may be transmitted to the inner sliding door  330  via the belt catcher  381  as well as the power transmission member including the gears  416  and  423  and the belt  440 . The magnetic sensor  460  may detect the rotation of the idle pulley  431  to inform of the position of the inner sliding door  330 . Furthermore, the photosensors  471  and  475  respectively disposed near a left limit position and a right limit position of the inner sliding door  330  may inform whether the inner sliding door  330  reaches the limit positions. The motor  411  may be driven by the drive printed circuit board  490  that may include a motor driver. The drive printed circuit board  490  may be controlled by a controller 5 configured to receive the signals from the magnetic sensor  460  and the photosensors  471  and  475  and to determine the position of the inner sliding door  330  and to determine the error of the driving unit  400 . The controller 5 may determine a target position of the inner sliding door  330  and may send a corresponding signal to the motor driver. The controller may be provided on the drive printed circuit board  490 . 
     Referring to  FIG. 50  and  FIG. 51 , the inner sliding door  330  may be driven by the driving unit  400  to start to move leftward when the inner sliding door  330  is expected to move from the rightmost position to the leftmost position. Referring to  FIG. 51  and  FIG. 52 , the outer sliding door  350  may not move until the outer bar  344  of the inner sliding door  330  meets the catching protrusions  354  of the outer sliding door  350 . Referring to  FIG. 52  and  FIG. 53 , the outer sliding door  350  may follow the inner sliding door  330  thereafter. The inner sliding door  330  may stop when it is determined that the inner sliding door  330  arrives at the left limit position, and then the outer sliding door  350  may also stop. 
     When the starting position of the inner sliding door  330  is the leftmost position, and the target position is the rightmost position, the inner sliding door  330  may be driven to start to move rightward while the outer sliding door  350  remains it rest state as shown in  FIG. 54 . Referring to  FIG. 55 , the inner sliding door  330  and the outer sliding door  350  may move together to their target positions after the catching protrusions  345  and  347  of the inner sliding door  330  contact the catching protrusions  354  of the outer sliding door  350 . Referring to  FIG. 52  and  FIG. 53 , the outer sliding door  350  may follow the inner sliding door  330  thereafter. The inner sliding door  330  may stop when it is determined that the inner sliding door  330  arrives at the left limit position, and then the outer sliding door  350  may also stop. 
     The multiple sliding door structure of the shutter assembly  300  may allow a wider open area than a single sliding door structure. Referring to  FIG. 56 , when a length L 0  is given for a door system, a double sliding door system may have a maximum open length L 1  equal to about two thirds of the given length L 0 , while a single sliding door system may have a maximum open length L 1  equal to about a half of the given length L 0 . Therefore, various rendering effects for a game may be obtained by applying a multiple sliding door system. 
     In order to conduct a variety of rendering effects for a game, the shutter assembly  300  may be precisely controlled. For example, the positions of both the sliding doors  330  and  350  may be precisely controlled in order to allow a game player to see images on the display panel  210  through the holes  336  and  337  because an image or a character to be shown to the player is aligned with the holes  336  and  337 . However, since the outer sliding door  350  is not driven independently, its position may not be unpredictable. 
     Referring to  FIG. 53 , the outer sliding door  350  and the inner sliding door  330  may be stuck together and may move at substantially the same speed after the outer bar  344  of the inner sliding door  330  meets the catching protrusions  354  of the outer sliding door  350  in a movement from right to left. In this case, when the inner sliding door  330  stops, the outer sliding door  350  may also stop at the same time. 
     However, referring to  FIG. 53  and  FIG. 56 , the outer sliding door  350  may move faster than the inner sliding door  330  after the outer bar  344  of the inner sliding door  330  meets the catching protrusions  354  of the outer sliding door  350  in a movement. In this case, the stop of the outer sliding door  350  may lag behind the stop of the inner sliding door  330 , or the outer sliding door  350  may not stop until the catching protrusions  354  of the outer sliding door  350  strikes the catching protrusions  345  and  347  of the inner sliding door  330  even though the inner sliding door  330  stops. 
     In the former case, it may be expected that the position of the outer sliding door  350  differs from the position of the inner sliding door  330  by a distance equal to about a width of the inner sliding door  330 . However, in latter case, the position of the outer sliding door  350  may vary in a range from the same position as the inner sliding door  330  to the position differing from the position of the inner sliding door  330  by a distance equal to about a width of the inner sliding door  330 . Therefore, the movements of the sliding doors  330  and  350  may be controlled like the former case. 
     A mechanism for obtaining expectable positions of the sliding doors  330  and  350  according to embodiments of the present invention is described in detail with reference to  FIG. 58  and  FIG. 59 . 
       FIG. 58  and  FIG. 59  are schematic top views of a track for the sliding doors according to embodiments of the present invention. 
     The moving speed of the outer sliding door  350  may depend on the friction between the outer sliding door  350  and the guide channels  312  and  322 . Therefore, the moving speed of the doors  330  or  350  may be controlled by adjusting the friction between the outer sliding door  350  and the guide channels  312  and  322 . For example, the friction between the outer sliding door  350  and the rear guide channels  312  and  322  may be set to be greater than the friction between the inner sliding door  330  and the front guide channels  311  and  321  so that the outer sliding door  350  may not move faster than the inner sliding door  330 . Since the rollers  333 ,  334 ,  356  and  357  directly contact the guide channels  311 ,  312 ,  321  and  322 , the friction between rollers  333 ,  334 ,  356  and  357  and the guide channels  311 ,  312 ,  321  and  322  may be adjusted. 
     According to an embodiment of the present invention, the walls of at least one of the rear guide channels  312  and  322  may be formed of a material having coefficient of friction greater than coefficient of friction of a material of the walls of the front guide channels  311  and  321 . 
     According to another embodiment of the present invention, referring to  FIG. 58 , an additional member  325  giving relatively large coefficient of friction to the outer sliding door  350 , for example, an oilless bearing may be added to an inner surface of at least one of the rear guide channels  312  and  322 . 
     According to another embodiment of the present invention, referring to  FIG. 59 , a width of at least one of the rear guide channels  312  and  322  may be narrower than the front guide channels  311  and  321  so that the outer sliding door  350  may move relatively hard compared with the inner sliding door  330 . 
     According to another embodiment of the present invention, the rollers  356  and  357  of the outer sliding doors  350  and  370  may include a material having coefficient of friction greater than coefficient of friction of a material of the rollers  333  and  334  of the inner sliding doors  330  and  360 . 
     Game Mode 
     Next, a game mode according to an embodiment of the present invention is described in detail with reference to  FIG. 60 . 
       FIG. 60  shows a state machine of a gaming mode in a gaming machine according to an embodiment of the present invention. 
     According to an embodiment of the present invention, a gaming machine executes a game in any one mode of a normal mode, a chance mode and a bonus mode, and switches one mode to another mode. Generally, the gaming machine starts a game (i.e., a normal mode game) in the normal mode as a base game, and maintains the normal mode unless a trigger event occurs. When a game result of the normal mode game satisfies the trigger event for the chance mode, the gaming machine switches the normal mode to the chance mode and starts a game (i.e., a chance mode game) in the chance mode. Further, when a game result of the normal mode game or the chance mode game satisfies the trigger event for the bonus mode, the gaming machine switches the normal mode or chance mode to the bonus mode and starts a game (i.e., a bonus mode game) in the bonus mode. The trigger event for the chance mode may be appearance of a specific symbol (“CHANCE”), and the trigger event for the bonus mode may be appearance of three or more scatter symbols (“BONUS”). The chance mode game or the bonus mode game is an additional game that is advanced from the normal mode game according to the game result of the normal mode game. 
     The gaming machine switches the chance mode to the normal mode when an ending condition of the chance mode is satisfied in the chance mode. The chance mode may be switched to the normal mode when the number of rounds executed in the chance mode is equal to a threshold. Further, the gaming machine switches the bonus mode to the normal mode when an ending condition of the bonus mode is satisfied in the bonus mode. The bonus mode may be switched to the normal mode when the number of rounds executed in the bonus mode is equal to a threshold. 
     Gaming Operations 
     Hereinafter, gaming operations in game modes according to embodiments of the present invention are described in detail with reference to  FIG. 61  to  FIG. 105 . For easy description, a left pair of sliding doors ( 360  and  370  of  FIG. 26 ) are shown and described as one left sliding door  71 , and a right pair of sliding doors ( 330  and  350  of  FIG. 26 ) are shown and described as one right sliding door  72 . 
     Normal Mode Game 
       FIG. 61  and  FIG. 62  show an example of a normal mode game according to an embodiment of the present invention,  FIG. 63  shows an example of a symbol code determination table for a normal mode game according to an embodiment of the present invention,  FIG. 64  to  FIG. 66  show examples of control data and image data according to an embodiment of the present invention,  FIG. 67  shows a trigger of a bonus mode game according to an embodiment of the present invention, and  FIG. 68  shows a trigger of a chance mode game according to an embodiment of the present invention. 
     Referring to  FIG. 61 , a plurality of reels  31   a  to  31   e  stop in a primary display  100  before a normal mode game is executed. Further, sliding doors  71  and  72  are opened in a secondary display  70 , and the secondary display  70  displays a background image for the normal mode game of a display panel  73 . For example, the background image may include a tree image and a rocky mountain image. The player bets a desired amount of credits, and starts the normal mode game. The player may bet the credits by pressing at least one of BET buttons ( 56   a  to  56   e  of  FIG. 8 ), and may start the normal mode game by pressing a START button ( 54  of  FIG. 8 ). When betting the credits, the player may select at least one of a plurality of pay lines such that the pay lines can be partially activated depending on the player&#39;s select. Alternatively, all the pay lines may be effective or activated irrespectively of the player&#39;s select. 
     If the player starts the normal mode game, the reels  31   a  to  31   e  starts to spin as shown in  FIG. 62 . Thus, symbols of symbol sequences scroll along with the spinning of the reels  31   a  to  31   e . After a certain time period elapses, the reels  31   a  to  31   e  stop spinning to rearrange the symbols on the symbol matrix. Three symbols of each symbol sequence appear on each of the reels  31   a  to  31   e  of the primary display  30  when each of the reels  31   a  to  31   e  stops. The gaming machine may randomly determine symbols to be stopped on each of the reels  31   a  to  31   e  based on the random number for each reel. In this case, the gaming machine may generate random numbers for the reels  31   a  to  31   e , determine codes corresponding to the random numbers, and determine the symbols to be arranged in the middle row of the symbol matrix based on the determined codes. 
     In one embodiment, a symbol code determination table for matching a code and a random number is stored in a memory. The memory may be a RAM ( 93  of  FIG. 9 ), a ROM ( 92  of  FIG. 9 ), or other storage devices. In an example shown in  FIG. 63 , the symbol code determination table stores each code and a range of random numbers corresponding to each code in table form. Accordingly, the gaming machine may determine the code corresponding to the generated random number based on the symbol code determination table stored in the memory. The range of random numbers corresponding to each code may determined by a probability of a winning combination for each symbol being satisfied, a probability of a bonus mode game being triggered (hereinafter referred to as “a bonus probability”), and/or a probability of a chance mode game being triggered (hereinafter referred to as “a chance probability”). 
     The gaming machine determines whether a combination of the symbols arranged on each pay line, i.e., a game result of the normal mode game satisfy a winning combination. The winning combination is a combination where the combination of symbols arranged on the pay line becomes a beneficial state for the player. The beneficial state is a state where credits corresponding to the winning combination are to be awarded the player, a state where a bonus mode game is to be triggered, or the like. Various winning combinations are predefined for all symbols. For example, when at least three identical symbols are continuously arranged from the first column on the pay line, the winning combination for the identical symbol is satisfied. The credits to be paid out may be varied according to a type of the identical symbol and/or the number of continuous identical symbols. 
     The gaming machine opens or closes the sliding doors  71  and  72  to expose an object image displayed on the display panel  73  of the secondary display  70 . Operations of the sliding doors  71  and  72  and the object image are varied according to a game result of the normal mode game. The game result of the normal mode game is any one of various types of game results. The gaming machine stores a plurality of rendering pattern data which respectively correspond to the various types of game results in a memory. The memory may be a RAM  93 , a ROM  92 , or other storage devices. 
     Referring to  FIG. 64 , the plurality of rendering pattern data include a plurality of control data for controlling the sliding doors  71  and  72  and a plurality of display data which correspond to the plurality of control data respectively, and the plurality of control data correspond to the various types of game results respectively. The plurality of control data and the plurality of display data define a plurality of rendering patterns. Accordingly, the gaming machine determines the game result by the symbol code determination table, and then selects a control data and an display data (i.e., a rendering pattern data) corresponding to the determined game result among the plurality of control data and the plurality of display data stored in the memory. If at least two rendering patterns correspond to the determined game result, the gaming machine may randomly determine any one among the at least two rendering patterns. Next, the gaming machine renders the rendering pattern by opening or closing the sliding doors  71  and  72  and displaying the object image on the display panel  73  according to the selected control data and display data, before the gaming result is displayed on the reels  31   a  to  31   e . The object image may be a character image, an article image, or a symbol image, etc. 
     Referring to  FIG. 65 , each control data may include at least one position data for determining positions of the sliding doors  71  and  72 . The at least one position data may correspond to a position data for fully closing the sliding doors  71  and  72 , a position data for fully opening the sliding doors  71  and  72 , and/or at least one position data for partially opening the sliding doors  71  and  72 . Each control data may further include at least one timing data corresponding to the at least one position data, and the timing data represents a timing when the sliding doors  71  and  72  are moved to positions indicated by the position data. Accordingly, the gaming machine can move positions of the sliding doors  71  and  72  to positions indicated by the position data at a time indicated by the timing data. 
     Referring to  FIG. 66 , each display data includes at least one object image, a display position data representing a position where the object image is displayed on the display panel  73 , and a display timing representing a timing when the object image is displayed on the display panel  73 . Furthermore, the position data and the timing data of the corresponding control data may be associated with the display position data and the display timing data of the corresponding display data. Accordingly, the gaming machine can display the object data on a position indicated by the display position data at a time indicated by the displaying timing data, and move the sliding doors  71  and  72  to expose at least part of the display panel  73 . As a result, the gaming machine can render the rendering pattern. 
     In one embodiment, regardless of the pay lines, when a combination of symbols rearranged on the reels  31   a  to  31   e , i.e., the game result satisfies a predetermined condition, a bonus mode game that is an additional game advanced from the normal mode game is triggered. In an example shown in  FIG. 67 , when scatter symbols (“BONUS”) with a number greater than a predetermined number (for example, 3) are arranged on the reels  31   a  to  31   e , the bonus mode game is triggered. In one embodiment, when the bonus mode game is triggered, left and right sliding doors  71  and  72  are closed in a secondary display  70 . Further, the gaming machine may output a sound for notifying a trigger of the bonus mode game. 
     In another embodiment, when a specific symbol (i.e., “CHANCE” symbol) is arranged on a predefined position of the reels  31   a  to  31   e , a chance mode game that is an additional game advanced from the normal mode game is triggered. In an example shown in  FIG. 68 , when the specific symbol (“CHANCE”) stops on the middle row of the third reel  31   c , the chance mode game is triggered. In one embodiment, when the chance mode game is triggered by the specific symbol (“CHANCE”), left and right sliding doors  71  and  72  are closed in a secondary display  70 . Further, the gaming machine may output a sound for notifying a trigger of the chance mode game. Furthermore, the gaming machine may chance a color of the reel  31   a  to  31   e  by controlling light sources ( 34   s  of  FIG. 10 ) of a backlight unit ( 34  of  FIG. 10 ). 
     A bonus probability of the chance mode game may be higher than a probability of the bonus mode game being triggered in the normal mode game. That is, the gamine machine may increase a probability with which the scatter symbol (“BONUS”) stops on each of the reels  31   a  to  31   e  in the chance mode game compared to the normal mode game. In one embodiment, the probability is randomly determined when the chance mode game is triggered. 
     As described above, the gaming machine according to an embodiment of the present invention can provide the chance mode game or the bonus mode game as well as a payout according to a result of the normal mode game. As a result, the player can continuously play the game to trigger the chance or bonus mode game in which the additional benefit and/or a visual rendering effect are provided. Further, since the gaming machine can provide various rendering effects according to the game result, the player can be interested in the game. 
     Next, a normal mode game according to various embodiments of the present invention is described in detail with reference to  FIG. 69  to  FIG. 81 . 
       FIG. 69  shows a start of an example of a normal mode game according to an embodiment of the present invention. 
     Referring to  FIG. 61  again, sliding doors  71  and  72  of a secondary display are opened when a normal mode game is executed. When the normal mode game is executed by the player, a controller (i.e., a main CPU  91  of  FIG. 9 ) of a gaming machine starts to spin reels  31   a  to  31   e  and raffles the sliding doors  71  and  72  of a secondary display, as shown in  FIG. 69 . The controller displays a background image on a display panel  73  of the secondary display  70 . Further, the controller randomly determines any one rendering pattern among a plurality of rendering patterns for the normal mode game according to a game result to be displayed, and selects a rendering pattern data including a control data and an image data for the determined rendering pattern from a memory. 
     The rendering patterns may include, for example, rendering patterns showing a sign of a bonus mode game being triggered (hereinafter referred to as “bonus sign rendering patterns”), rendering patterns showing a sign of a chance mode game being triggered (hereinafter referred to as “chance sign rendering patterns”), or rendering patterns for determining credits to be paid out to the player (hereinafter referred to as “payout rendering patterns”), etc. The controller of the gaming machine may control the sliding doors  71  and  72  and the display panel  73 , to render a rendering pattern according to the selected rendering pattern data. 
     As such, since the gaming machine provides the various rendering patterns and randomly selects the rendering patterns, the player can continuously play the game to experience the various rendering patterns. 
     First, the bonus sign rendering patterns are described with reference to  FIG. 70  to  FIG. 78 . The bonus sign rendering patterns may include various types of bonus sign rendering patterns according to various embodiments, and each type may include a plurality of bonus sign rendering patterns having the different bonus probabilities. 
       FIG. 70  to  FIG. 78  show examples of bonus sign rendering patterns in a normal mode game according to an embodiment of the present invention. 
     Type 1 of Bonus Sign Rendering Pattern 
     The type 1 of bonus sign rendering patterns may include a plurality of rendering patterning including a rendering pattern 1, a rendering pattern 2, and a rendering pattern 3. When the normal mode game is started, symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) are randomly determined based on a symbol code determination table. A controller of a gaming machine selects any one of the plurality of rendering patterns. That is, the controller selects a control data and an image data among a plurality of control data and a plurality of image data for the plurality of rendering patterns. Next, a background image, which is displayed on a display panel  73  of the secondary display  70 , slides to the right as shown in  FIG. 70  and  FIG. 71 . In this case, the reels  31   a  to  31   e  are continuously spinning. 
     If the determined rendering pattern is the rendering pattern 1, the background image slides to the right such that an entire image of a left part of the background image appears, as shown in  FIG. 70 . The left part may be, for example, a tree image. When the rendering pattern 1 is rendered, the bonus probability of the normal mode game is set to a probability 1. After the rendering pattern 1 is rendered, three or more scatter symbols (“BONUS”) can appear on the stopped reels  31   a  to  31   e  with the probability 1. That is, the bonus mode game can be triggered with the possibility 1 in the current normal mode game. The probability 1 may be, for example, 10%. 
     If the determined rendering pattern is the rendering pattern 2, the background image slides to the right such that an object image NC 1  corresponding to a main character is display on the entire image of the left part, as shown in  FIG. 71 . For example, the main character NC 1  may be Ali Baba in the story of “Ali Baba and the Forty Thieves.” When the rendering pattern 2 is rendered, the bonus probability of the normal mode game is set to a probability 2 that is higher than the probability 1. After the rendering pattern 2 is rendered, the three or more scatter symbols (“BONUS”) can appear on the stopped reels  31   a  to  31   e  with the probability 2. That is, the bonus mode game can be triggered with the possibility 2 in the current normal mode game. For example, the probability 2 may be 33%. 
     If the determined rendering pattern is the rendering pattern 3, the gaming machine renders the rendering pattern 2 and then closes the left sliding door  71  as shown in  FIG. 72 . As a result, the left sliding door  71  bumps into the main character NC 1  and the main character NC 1  moves to the right. Subsequently, the background image BG 1  slides to the left such that an entire image of a right part of the background image appears, as shown in  FIG. 72 . The right part may be a rocky mountain image. An object image NC 2  corresponding to opponent characters may be displayed on the right part. That is, the main character NC 1  moved to the right meets opponent characters NC 2 . For example, the opponent characters NC 2  may be thieves in the story of “Ali Baba and the Forty Thieves.” When the rendering pattern 3 is rendered, the bonus probability of the normal mode game is set to a probability 3 that is higher than the probability 2. After the rendering pattern 3 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 3. For example, the probability 3 may be 100%. That is, the bonus mode game can be always triggered if the rendering pattern 3 is rendered. 
     For example, when the controller determines that the scatter symbol (“BONUS)” is arranged on the first reel  31   a , the rendering mode 1 may be rendered. That is, the probability 1 may be a probability of at least two scatter symbols (“BONUS”) being arranged on remaining four reels  31   b  to  31   e . When the controller determines that the two scatter symbols (“BONUS)” are arranged on two reels among the first to third reels  31   a  to  31   c , the rendering mode 2 may be rendered. That is, the probability 2 may be a probability of at least one symbol (“BONUS”) being arranged on remaining two reels  31   d  and  31   e . When the controller determines that the three scatter symbols (“BONUS)” are arranged on three reels among the reels  31   a  to  31   e , the rendering mode 3 may be rendered. 
     Type 2 of Bonus Sign Rendering Pattern 
     The type 2 of bonus sign rendering patterns may include a plurality of rendering patterning including a rendering pattern 4, a rendering pattern 5, and a rendering pattern 6. When the normal mode game is started, symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) are randomly determined based on a symbol code determination table. A controller of a gaming machine selects any one of the plurality of rendering patterns. That is, the controller selects a control data and an image data among a plurality of control data and a plurality of image data for the plurality of rendering patterns. Next, a background image BG 2 , which is displayed on a display panel  73  of the secondary display  70 , slides to the left as shown in  FIG. 73  and  FIG. 74 . In this case, the reels  31   a  to  31   e  are continuously spinning. 
     If the determined rendering pattern is the rendering pattern 4, the background image BG 2  slides to the left such that an entire image of a right part of the background image appears, as shown in  FIG. 73 . The right part may be, for example, a rocky mountain image. When the rendering pattern 4 is rendered, the bonus probability of the normal mode game is set to a probability 4. After the rendering pattern 4 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 4. The probability 4 may be, for example, 10%. 
     If the determined rendering pattern is the rendering pattern 5, the background image BG 2  slides to the left such that an object image corresponding to opponent characters NC 3  together with the entire image of the right part appears, as shown in  FIG. 74 . For example, the opponent characters NC 3  may be thieves in the story of “Ali Baba and the Forty Thieves.” When the rendering pattern 5 is rendered, the bonus probability of the normal mode game is set to a probability 5 that is higher than the probability 4. After the rendering pattern 5 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 5. For example, the probability 5 may be 33%. 
     If the determined rendering pattern is the rendering pattern 6, the controller renders the rendering pattern 5 and then closes the right sliding door  72  as shown in  FIG. 75 . As a result, the right sliding door  72  bumps into the opponent characters NC 3  and the opponent characters NC 3  move to the left. Subsequently, the background image slides to the right such that an entire image of a left part of the background image appears, as shown in  FIG. 75 . The left part may be a tree image. An object image NC 4  corresponding to a main character may be displayed on the right part. That is, the opponent characters NC 3  moved to the left meet the main character NC 4 . The main character NC 4  may be, for example, Ali Baba in the story of “Ali Baba and the Forty Thieves.” When the rendering pattern 6 is rendered, the bonus probability of the normal mode game is set to a probability 6 that is higher than the probability 5 of the rendering pattern. After the rendering pattern 6 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 6. For example, the probability 6 may be 100%. 
     For example, when the controller determines that the scatter symbol (“BONUS)” is arranged on the first reel  31   a , the rendering mode 4 may be rendered. When the controller determines that the two scatter symbols (“BONUS)” are arranged on two reels among the first to third reels  31   a  to  31   c , the rendering mode 5 may be rendered. When the controller determines that the three scatter symbols (“BONUS)” are arranged on three reels among the reels  31   a  to  31   e , the rendering mode 6 may be rendered. 
     Type 3 of Bonus Sign Rendering Pattern 
     The type 3 of bonus sign rendering patterns may include a plurality of rendering patterning including a rendering pattern 7 and a rendering pattern 8. When the normal mode game is started, symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) are randomly determined based on a symbol code determination table. A controller of a gaming machine selects any one of the plurality of rendering patterns. That is, the controller selects a control data and an image data among a plurality of control data and a plurality of image data for the plurality of rendering patterns. Next, one side sliding door, for example a left sliding door  71  of a secondary display  70  is closed, as shown in  FIG. 76 . In this case, the reels  31   a  to  31   e  are continuously spinning. 
     If the determined rendering pattern is the rendering pattern 7, an object image NC 5  is displayed on a display panel  73  of the secondary display  70 , and appears through at least one hole  74   a  of the left sliding door  71 , as shown in  FIG. 77 . For example, the object image NC 5  may be an eye of an opponent character. Subsequently, the left sliding door  71  is opened and an object image corresponding to a character NC 6  is displayed on the display panel  73 . The character NC 6  may be, for example, a head thief or Morgiana in the story of “Ali Baba and the Forty Thieves.” After the rendering pattern 7 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 7. For example, the probability 7 may be 33%. 
     If the determined rendering pattern is the rendering pattern 8, the left sliding door  71  is opened in a moment, and then the left and right sliding doors  71  and  72  are closed, as shown in  FIG. 78 . Subsequently, the left and right sliding doors  71  and  72  are opened and an object image NC 7  representing a bonus mode appears on the display panel  73 . For example, the object image NC 7  representing the bonus mode may be “BONUS” symbol. When the rendering pattern 8 is rendered, the bonus probability of the normal mode game is set to a probability 8 that is higher than the probability 7. After the rendering pattern 8 is rendered, three or more scatter symbols (“BONUS”) can stop on the reels  31   a  to  31   e  with the probability 8. For example, the probability 8 may be 100%. That is, the bonus mode game can be always triggered if the rendering pattern 8 is rendered. 
     For example, when the controller determines that the two scatter symbols (“BONUS)” are arranged on two reels among the first to third reels  31   a  to  31   c , the rendering mode 7 may be rendered. When the controller determines that the three scatter symbols (“BONUS)” are arranged on three reels among the reels  31   a  to  31   e , the rendering mode 8 may be rendered. 
     As described above, the gaming machine according to the above embodiment can show a sign of a bonus mode game being triggered by using the sliding doors  71  and  72 . Accordingly, the player can play the game with the expectation that the bonus mode game will be triggered. 
     Next, the chance sign rendering pattern is described in detail with reference to  FIG. 79 . 
       FIG. 79  shows an example of a chance sign rendering patterns in a normal mode game according to an embodiment of the present invention. 
     Chance Sign Rendering Pattern 
     When symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) that are randomly determined based on a symbol code determination table satisfy a triggering condition of a chance mode game, a controller of a gaming machine may select a control data and an image data for a chance sign rendering pattern among a plurality of control data and a plurality of image data. Then, a display panel  73  of a secondary display  70  and reels  31   a  to  31   e  are darkened, and then a backlight unit ( 34  of  FIG. 10 ) of the reels  31   a  to  31   e  controls a light to be focused on a center of the reel  31   a  to  31   e , as shown in  FIG. 79 . Subsequently, an object image NC 8  representing a chance mode appears on a display panel  73  of the secondary display  70 , and the backlight unit  34  focuses the light on the center of the reels  31   a  to  31   e . For example, the object image NC 8  representing the chance mode may be “CHANCE” symbol. After the chance sign rendering pattern is rendered, a specific symbol (“CHANCE”) stops on the middle row of the third reel  31   c . That is, the chance mode game is triggered after the chance sign rendering pattern is rendered. 
     As described above, the gaming machine according to the above embodiment can notify the player of a trigger of the chance mode game using the sliding doors  71  and  72 . Accordingly, the gaming machine can provide the player with a visual effect when the chance mode game is triggered. 
     Next, the payout rendering patterns are described in detail with reference to  FIG. 80  and  FIG. 81 . The payout rendering patterns may include various types of payout rendering patterns according to various embodiments. 
       FIG. 80  and  FIG. 81  show examples of payout rendering patterns in a normal mode game according to an embodiment of the present invention. 
     Type 1 of Payout Rendering Pattern 
     When symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) that are randomly determined based on a symbol code determination table do not include a particular symbol such as a scatter symbol (“BONUS”), a specific symbol (“CHANCE”), or a “WILD” symbol, a controller of a gaming machine may select a control data and an image data for a type 1 of payout rendering pattern among a plurality of control data and a plurality of image data. Then, left and right sliding doors  71  and  72  are closed and at least one hole  74   b  and/or  74   e  appears on the sliding doors  71  and  72 , as shown in  FIG. 80 . When a plurality of holes  74   b  and  74   e  appears, the holes  74   b  and  74   e  may sequentially appear on the sliding doors  71  and  72 . In this case, an effect that an earthquake hits the sliding doors  71  and  72  such that at least one rock on the sliding doors  71  and  72  crumbles and the at least one hole  74   b  and/or  74   e  appears may be rendered. Further, a roulette having images representing a plurality of payout ratios rotates on a display panel  73  of a secondary display  70 , and some of the payout ratios are shown through the hole. 
     Subsequently, the reels  31   a  to  31   e  stop to spin, and the rotation speed of the roulette is gradually reduced. When the reels  31   a  to  31   e  are stopped, a winning combination of the symbols is determined by the symbols arranged on the reels  31   a  to  31   e . After the rotation of the roulette is stopped, the payout ratio shown through the at least one hole is applied to a payout according to the winning combination. For example, assuming that a payout ratio corresponding to two times (“×2”) and a payout ratio corresponding to five times (“×5”), ten times the payout according to the winning combination is awarded to the player. If no payout ratio is shown through the at least one hole, only the payout according to the winning combination is awarded to the player. 
     Type 2 of Payout Rendering Pattern 
     When symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) that are randomly determined based on a symbol code determination table include “WILD” symbols with a number greater than a predetermined number, a controller of a gaming machine may select a control data and an image data for a type 2 of payout rendering pattern among a plurality of control data and a plurality of image data. Then, left and right sliding doors  71  and  72  are closed and characters appear or disappear on a display panel  73  of a second display device  70 , as shown in  FIG. 81 . When the characters are displayed on the display panel  73 , faces of the characters are shown through holes  74   a  to  74   e  of the sliding doors  71  and  72 . 
     Subsequently, the sliding doors  71  and  72  are open, and the characters whose faces are shown through the holes  74   a  to  74   e  are displayed at locations corresponding to the holes  74   a  to  74   e  on the display panel  73 . Next, the characters jump into reels corresponding to the locations among the reels  31   a  to  31   e  such that the “WILD” symbols are stopped on the reels into which the characters jump. The three “WILD” symbols may be stopped on each of the reels into which the characters jump. Subsequently, the remaining reels are stopped, and a winning combination is determined by the “WILD” symbols and symbols arranged on the remaining reels. A payout according to the winning combination is determined and is awarded to the player. 
     As described above, the gaming machine according to the above embodiment can provide the player with the additional benefit along with a visual effect using the sliding doors  71  and  72 . Accordingly, the player can be interested in the game through the visual effect. 
     Bonus Mode Game 
     Next, a bonus mode game according to embodiments of the present invention is described in detail with reference to  FIG. 82  to  FIG. 91 . 
     Referring to  FIG. 67  again, when three or more scatter symbols (“BONUS”) are arranged on reels  31   a  to  31   e , a bonus mode game is triggered, and left and right sliding doors  71  and  72  are closed in a secondary display  70 . The gaming machine provides various bonus types for the bonus mode game. Accordingly, a controller of the gaming machine randomly determines any one of the various bonus types, and selects a rendering pattern data corresponding to the determined bonus type among a plurality of rendering pattern data for the bonus mode game stored in a memory. The rendering pattern data may include a control data for controlling the sliding doors  71  and  72  and an image data corresponding to the control data, as described in the normal mode game. 
     Subsequently, the controller opens the sliding doors  71  and  72  according to the selected rendering pattern data. When the sliding doors  71  and  72  are opened, an image corresponding to the selected rendering pattern data is displayed on a display panel  73  of the secondary display  70 . The controller may control the sliding doors  71  and  72 , the display panel  73  and the reels  31   a  to  31   e , to render an effect according to the selected rendering pattern data. Further, the bonus mode game may include at least one free round. The free round can be executed without actual betting of the player (i.e., without reducing credits of the player), and the bet amount used for determining the win prize of the free round may be that of the normal mode game executed just before the bonus mode game. 
     Hereinafter, the various bonus types for the bonus mode game are described. The controller of the gaming machine controls the sliding doors  71  and  72  and the display panel  73  to render an effect according to the selected rendering pattern data. 
     Bonus Type 1 
       FIG. 82  shows an example of a rendering pattern for a bonus mode game according to an embodiment of the present invention, and  FIG. 83  shows an example of a bonus mode game according to the rendering pattern shown in  FIG. 82 . 
     When the bonus type 1 is determined, an object image BT 1  for notifying the bonus type 1 is displayed on the display panel  73  and are shown through the open sliding doors  71  and  72 , as shown in  FIG. 82 . For example, the object image BT 1  may be an image that a plurality of characters appear, and the characters may be thieves in the story of “Ali Baba and the Forty Thieves.” After the image is displayed, the gaming machine provides the player with the bonus mode game including a plurality of free rounds. 
     In each free round, reels  31   a  to  31   e  starts to spin and an object image corresponding to the characters BC 1  is displayed on the display panel  73 , as shown in  FIG. 83 . In certain free round, an effect that the characters BC 1  jump into at least one of the reels  31   a  to  31   e  which are spinning may be rendered on the display panel  73 . Subsequently, “WILD” symbols are stopped on the reel into which the characters BC 1  jump, and then the remaining reels are stopped. In this case, the controller may render the effect that the characters BC 1  jump into the reel when the “WILD” symbol is determined to stop on the reel based on the symbol code determination table. The controller determines a winning combination by the “WILD” symbols and symbols arranged on the remaining reels, and provides the player with a payout according to the winning combination. On the other hand, in the free round in which the effect that the characters jump into at least one of the reels  31   a  to  31   e  is not rendered, the gaming machine determines a winning combination by symbols arranged on the reels  31   a  to  31   e.    
     The controller counts the number of executed free rounds each time the free round is executed, and ends the bonus mode game and returns to a normal mode game when the number of free rounds reaches a predetermined number, for example seven. Further, in each free round, the controller may randomly determine whether to render or not an effect that the characters jump into at least one of the reels  31   a  to  31   e . In this case, the gaming machine may predefine an expected value of credits that are awarded to the player during the bonus mode game, and may set a range of random numbers corresponding to the effect that the characters jump into at least one of the reels  31   a  to  31   e  according to the expected value. Accordingly, the gaming machine may generate a random number each time the free round is executed, and may perform the effect when the random number is within the range of the random numbers. 
     Bonus Type 2 
       FIG. 84  shows another example of a rendering pattern for a bonus mode game according to an embodiment of the present invention, and  FIG. 85  shows an example of a bonus mode game according to the rendering pattern shown in  FIG. 84 . 
     When the bonus type 2 is determined, an object image BT 2  for notifying the bonus type 2 is displayed on the display panel  73  and are shown through the open sliding doors  71  and  72 , as shown in  FIG. 85 . For example, the object image BT 2  may be an image that a main character appears, and the main character may be Ali Baba in the story of “Ali Baba and the Forty Thieves.” After the object image BT 2  is displayed, the controller provides the player with the bonus mode game including a plurality of free rounds. 
     In each free round, reels  31   a  to  31   e  starts to spin and an object image corresponding to opponent characters BC 2  is displayed on the display panel  73 , as shown in  FIG. 85 . For example, the opponent characters BC 2  may be thieves in the story of “Mi Baba and the Forty Thieves.” In addition, the opponent characters BC 2  may correspond to the reel  31   a  to  31   e , respectively. In certain free round, the scatter symbol (“BONUS”) may be stopped on at least one of the reels  31   a  to  31   e  when the reels  31   a  to  31   e  stop. Subsequently, the gaming machine renders an effect that a light is emitted from a symbol block on which the scatter symbol is stopped to the opponent character BC 2  corresponding to the reel on which the scatter symbol is stopped. Next, an effect that the main character BC 3  defeats the opponent character BC 2  and a benefit is provided from the defeated opponent character BC 3  is rendered on the display panel  73 . The benefit may be a payout of credits and additional free round. In addition, the gaming machine determines a winning combination by symbols arranged on the remaining reels, and provides the player with a payout according to the winning combination. 
     The controller counts the number of executed free rounds each time the free round is executed, and ends the bonus mode game and returns to a normal mode game when the number of free rounds reaches a predetermined number, for example eight. Further, in each free round, the controller may randomly determine the symbols to be stopped on the reels  31   a  to  31   e . In this case, the controller may predefine an expected value of credits that are awarded to the player during the bonus mode game, and may set a range of random numbers corresponding to each symbol of a symbol code determination table according to the expected value. 
     Bonus Type 3 
       FIG. 86  shows yet another example of a rendering pattern for a bonus mode game according to an embodiment of the present invention,  FIG. 87  to  FIG. 90  show examples of a bonus mode game according to the rendering pattern shown in  FIG. 86 , and  FIG. 91  shows an example of symbol code determination tables for a bonus mode game according to an embodiment of the present invention. 
     When the bonus type 3 is determined, an object image BT 3  corresponding to the bonus type 3 is displayed on the display panel  73  and are shown through the open sliding doors  71  and  72 , as shown in  FIG. 86 . For example, the object image BT 3  may an image that a treasure chest appears. After the object image BT 3  is displayed, the gaming machine provides the player with the bonus type 3 of bonus mode game. The bonus type 3 of the bonus mode game may be a board game including a plurality of cells that form a course on which a character moves, and may include a plurality of free rounds. The character can move from a start cell to a goal cell during the plurality of free rounds. 
     In each free round, a map including a plurality of cells that form the course and the character BC 4  located at a current cell are displayed on a display panel  73  of the secondary display  70 , as shown in  FIG. 87 . When reels  31   a  to  31   e  stop after spinning, at least one scatter symbol (“BONUS”) may be appeared on the reels  31   a  to  31   e . The controller moves the character BC 4  from the current cell to a destination cell by the number of the scatter symbol(s). For example, when two scatter symbols are appeared on the reels  31   a  to  31   e , the character BC 4  is moved by two cells. Subsequently, the controller provides the player with an event set to the destination cell. If the destination cell is a cell C 10  to which a fixed credit value is set, the controller awards credits corresponding to the fixed credit value to the player. After a plurality of free rounds are performed, the character may arrive at a cell corresponding to a goal point of the course. Then, the controller awards credits of the goal point to the player. The credits of the goal point may be greater than credits of the other cells. 
     If the destination cell at which the character arrives is a cell C 20  to which a treasure chest is set, the gaming machine randomly determines a content of the treasure chest and opens the treasure chest to provide the content to the player. The content of the treasure chest may be a fixed credit value, moving by predetermined cells, etc. 
     If the destination cells is a cell C 30  corresponding to a turning point, the controller closes the sliding doors  71  and  72 , as shown in  FIG. 88 . The character is moved to any one of at least two cells including a cell C 40  to which an end of the game is set and a cell C 50  to which the fixed credit value or the treasure chest is set. The controller randomly determines any one of the at least two cells, and moves the character to the determined cell after opening the sliding doors  71  and  72 . 
     In one embodiment, if the destination cell is an end cell C 60  to which an end of the game is set, the gaming machine ends the bonus mode game. 
     In another embodiment, the gaming machine renders an ending event and determines whether to end the bonus mode game according to a result of the ending event. Referring to  FIG. 89 , the gaming machine closes the sliding doors  71  and  72  when the character BC 4  arrives at the end cell C 60 , and provides at least one free sub-round. In each free sub-round, the controller renders an effect that a character is displayed on the display panel  73  and gradually appears through a hole  74   c  located between the left and right sliding doors  71  and  72 . 
     If the player presses a certain button, for example a START button ( 54  of  FIG. 8 ) when the character appears through the hole  74   c , the sliding doors  71  and  72  attempt to sandwich the character by being opened and closed. When an effect that the character is defeated by being sandwiched by the sliding doors  71  and  72  is rendered, the controller awards predetermined credits to the player and executes a next free sub-round. If a character is successfully defeated in the last free sub-round, the controller does not end the bonus mode game and continuously executes a next free round of the bonus mode game at the end cell C 60 . If the player fails to defeat character, the controller notifies the player of the end of the bonus mode game and returns to a normal mode game. The character may be, for example, a thief in the story of “Ali Baba and the Forty Thieves,” and the character appeared in the last free sub-round may be a head thief. 
     In yet another embodiment, when the character arrives at the end cell C 60 , the controller closes the sliding doors  71  and  72  and randomly determines whether to end the bonus mode game. If the controller determines to continue the bonus mode game, it renders an effect that an object image corresponding to a character BC 5  opens the sliding doors  71  and  72 , as shown in  FIG. 90 . Accordingly, the gaming machine continuously executes a next free round of the bonus mode game at the end cell C 60 . If the gaming machine determines to end the bonus mode game, it notifies the player of the end of the bonus mode game and returns to the normal mode game. 
     In yet another embodiment, the controller predefines an expected value of credits that to be awarded to the player during the bonus type 3 of bonus mode game, and can set events and payouts for cells of the map according to the expected value. 
     In one embodiment, the gaming machine stores a plurality of symbol code determination tables corresponding to a plurality of bonus types in a memory, as shown in  FIG. 91 . The memory may be a RAM ( 93  of  FIG. 9 ), a ROM ( 92  of  FIG. 9 ), or other storage devices. The controller may select the symbol code determination table for the determined bonus type from the memory when selecting the rendering pattern data from the memory. In the symbol code determination table for the bonus type 1, a range (BL 1 P˜BU 1 Q, BL 2 P˜BU 2 Q, BL 3 P˜BU 3 Q, BL 4 P˜BU 4 Q, or BL 5 P˜BU 5 Q) of random numbers for the “WILD” symbol is wider than a range (NL 1 P˜NU 1 Q, NL 2 P˜NU 2 Q, NL 3 P˜NU 3 Q, NL 4 P˜NU 4 Q, or NL 5 P˜NU 5 Q) of random numbers for the scatter symbol in  FIG. 63 . Accordingly, a probability of the “WILD” symbol being stopped can be increased in the bonus type 1. In the symbol code determination tables for the bonus types 2 and 3, a range (BL 1 F˜BU 1 G, BL 2 F˜BU 2 G, BL 3 F˜BU 3 G, BL 4 F˜BU 4 G, or BL 5 F˜BU 5 G) of random numbers for the scatter symbol (“BONUS”) is wider than a range (NL 1 F˜NU 1 G, NL 2 F˜NU 2 G, NL 3 F˜NU 3 G, NL 4 F˜NU 4 G, or NL 5 F˜NU 5 G) of random numbers for the scatter symbol in  FIG. 63 . Accordingly, a probability of the scatter symbol being stopped can be increased in the bonus type 2 or 3. 
     In another embodiment, the game machine predefines an expected value of credits to be awarded during each bonus type of bonus mode game, and set a probability of each bonus type being determined to be inversely proportional to the expected value. For example, the gaming machine may set the expected value of the bonus type 3 to the greatest value and the expected value of the bonus type 3 to the least value. Further, the gaming machine may set the probability of the bonus type 3 being determined to the lowest value and the probability of the bonus type 1 being determined to the highest value. 
     As described above, the gaming machine according to the above embodiment can provide various visual effects and additional benefits in the bonus mode game. As a result, the player can continuously play the game to trigger the bonus mode game in which the additional benefits and the visual rendering effects are provided. Further, the player can continuously play the game to experience the various types of bonus mode games that are randomly determined. 
     Chance Mode Game 
     Next, a chance mode game according to embodiments of the present invention is described in detail with reference to  FIG. 92  to  FIG. 105 . 
       FIG. 92  shows an example of a chance mode game according to an embodiment of the present invention, and  FIG. 93  shows an example of symbol code determination tables for a chance mode game according to an embodiment of the present invention. 
     Referring to  FIG. 68  again, when a specific symbol (“CHANCE”) is arranged on a predefined position of the reels  31   a  to  31   e , a chance mode game is triggered, and left and right sliding doors  71  and  72  are closed in a secondary display  70 . A gaming machine provides various chance types for the chance mode game. Accordingly, the gaming machine determines any one among the various chance types. In one embodiment, the gaming machine may randomly determine a game result of the chance mode game, and determines a chance type corresponding to the game result among the various chance types. In another embodiment, the gaming machine may randomly determine a chance type among the various chance types regardless of the game result. After determining the chance type, the gaming machine selects a rendering pattern data of a rendering pattern corresponding to the determined chance type among a plurality of rendering pattern data stored in a memory. The rendering pattern data may include a control data for controlling the sliding doors  71  and  72  and an image data corresponding to the control data, as described in the normal mode game. 
     Subsequently, the controller starts to spin reels  31   a  to  31   e  and opens the sliding doors  71  and  72  halfway according to the selected rendering pattern data, as shown in  FIG. 92 . In this case, each of the left and right sliding doors  71  and  72  may be opened halfway or only one of the left and right sliding doors  71  and  72  may be fully opened. Further, the controller controls a backlight unit ( 34  of  FIG. 10 ) for the reels  31   a  to  31   e  to make the player look up the secondary display  70 . For example, the controller may turn on light sources ( 34   s  of  FIG. 10 ) that correspond to lower rows of the first and fifth reels  31   a  and  31   e , a middle row of the second and fourth reels  31   b  and  31   d , and an upper row of the third reel  31   c  among light sources  34   s  of the backlight unit  34 . The controller of the gaming machine may control the sliding doors  71  and  72  and the display panel  73 , to render a rendering pattern according to the selected rendering pattern data. 
     The chance types may include, for example, chance types showing a sign of a bonus mode game being triggered (hereinafter referred to as “chance types for bonus sign”), chance types for determining credits to be paid out to the player (hereinafter referred to as “chance types for payout”), chance types showing a probability of a bonus mode game being triggered (hereinafter referred to as “chance types for bonus probability”), or chance types showing an event (hereinafter referred to as “chance types for event”), etc. 
     The chance mode game may include a plurality of chance rounds, for example ten chance rounds. Accordingly, the gaming machine may randomly determine the plurality of chance types (i.e., a plurality of game results) for the plurality of chance rounds when the chance mode game is executed. Alternatively, the controller may select a chance type (i.e., a game result) for each chance round when each chance round is executed. The chance round may be executed without actual betting of the player (i.e., without reducing credits of the player), and the bet amount used for determining the win prize of the chance round may be that of the normal mode game executed just before the chance mode game. Alternatively, the chance round may be executed with actual betting of the player. The gaming machine counts the number of executed chance rounds each time the chance round is executed, and ends the chance mode game and returns to a normal mode game when the number of chance rounds reaches a predetermined number, for example ten. Further, if the bonus mode game is triggered in a certain chance round, the gaming machine ends the chance mode game and executes the bonus mode game. 
     In the chance mode game, symbols to be arranged on the reels  31   a  to  31   e  (i.e., a game result) may be determined by codes that are randomly determined based on the symbol code determination tables for the chance mode game. In detail, the gaming machine stores a plurality of symbol code determination tables in a memory, as shown in  FIG. 93 . The memory may be a RAM ( 93  of  FIG. 9 ), a ROM ( 92  of  FIG. 9 ), or other storage devices. Each of the symbol code determination tables has a higher bonus probability than the symbol code determination table for the normal mode game. That is, a range (CL 1 F˜CU 1 G, CL 2 F˜CU 2 G, CL 3 F˜CU 3 G, CL 4 F˜CU 4 G, or CL 5 F˜CU 5 G) of random numbers for the scatter symbol is wider than a range (NL 1 F˜NU 1 G, NL 2 F˜NU 2 G, NL 3 F˜NU 3 G, NL 4 F˜NU 4 G, or NL 5 F˜NU 5 G) of random numbers for the scatter symbol in  FIG. 63 . Further, the bonus probabilities may different between the symbol code determination tables. In one embodiment, the gaming machine may randomly select the symbol code determination table among the symbol code determination table stored in the memory, and may apply the selected symbol code determination table to the determined chance type. In another embodiment, the gaming machine may select the symbol code determination table corresponding to the determined chance type among the symbol code determination table stored in the memory. 
     As such, since the gaming machine provides the various chance types and randomly selects the chance types, the player can continuously play the game to experience the various chance types. Further, since the gaming machine can provide various rendering effects according to the various chance types, the player can be interested in the game. 
     Hereinafter, the various chance types for the chance mode game are described. The controller of the gaming machine controls the sliding doors  71  and  72  and the display panel  73  to render an effect according to the selected rendering pattern data. 
     First, the chance types for bonus sign are described with reference to  FIG. 94  to  FIG. 96 . The chance types for bonus sign may include various chance types according to various embodiments. 
       FIG. 94  to  FIG. 97  show examples of a chance type for bonus sign in a chance mode game according to an embodiment of the present invention. 
     Chance Type 1 for Bonus Sign 
     When the chance type 1 for bonus sign is determined, a controller of a gaming machine displays an object image corresponding to a character CC 1  on a display panel  73 , and attempts to fully open the sliding doors  71  and  72  while reels  31   a  to  31   e  are spinning, as shown in  FIG. 94 . As the sliding doors  71  and  72  are gradually opened, the reels  31   a  to  31   e  sequentially stop such that scatter symbols (“BONUS”) appears on some of the stopped reels  31   a  to  31   e . When the character CC 1  opens the sliding doors  71  and  72  fully, the three scatter symbols (“BONUS”) are arranged on the three stopped reels  31   a  to  31   e , for example the first, third and fifth reels  31   a ,  31   c  and  31   e . As a result, a bonus mode game is triggered. On the other hand, when the two or less scatter symbols (“BONUS”) are arranged on the reels  31   a  to  31   e , the sliding doors  71  and  72  are closed again. 
     Chance Type 2 for Bonus Sign 
     When the chance type 2 for bonus sign is determined, a controller closes the sliding doors  71  and  72  while reels  31   a  to  31   e  are spinning, and a plurality of holes  74   a  to  74   e  appear on the sliding doors  71  and  72 , as shown in  FIG. 95 . In this case, an effect that an earthquake hits the sliding doors  71  and  72  may be rendered such that rocks on the sliding doors  71  and  72  crumble and the holes  74   a  to  74   e  appear. When alphabets “B,” “O,” “N,” “N,” and “S” corresponding to “BONUS” are displayed on a display panel  73  of a second display device  70  and appeared through the holes  74   a  to  74   e , the three scatter symbols (“BONUS”) are arranged on the three stopped reels  31   a  to  31   e . As a result, the bonus mode game is triggered. 
     Chance Type 3 for Bonus Sign 
     When the chance type 3 for bonus sign is determined, a plurality of holes  74   a  to  74   e  appear on the sliding doors  71  and  72  like the type 2 of bonus sign rendering pattern. Subsequently, the controller renders an effect that opponent characters pass the holes  74   a  to  74   e  on a display panel  73  of a second display device  70 , as shown in  FIG. 96 . Next, the controller opens the sliding doors  71  and  72  halfway, and renders an effect that an object image corresponding to a particular character CC 2  runs after an object image corresponding to the opponent characters CC 3  when determining to trigger the bonus mode game. Accordingly, the three scatter symbols (“BONUS”) are arranged on the three stopped reels  31   a  to  31   e . The particular character CC 2  and the opponent character CC 3  may be, for example, Morgiana and thieves in the story of “Ali Baba and the Forty Thieves,” respectively. On the other hand, an effect that a head thief runs after the thieves may be rendered when the bonus mode game is not triggered. 
     As described above, the gaming machine according to the above embodiment can show a sign of a bonus mode game being triggered by using the sliding doors  71  and  72 . Accordingly, the player can play the game with the expectation that the bonus mode game will be triggered. Further, the player can continuously play the game to trigger the chance mode game in which the bonus mode game can be triggered with a high probability. 
     In another embodiment, the gaming machine can notify the player of the trigger of the bonus mode game without the bonus sign rendering pattern. Referring to  FIG. 97 , when the symbols to be arranged on reels  31   a  to  31   e  satisfy a condition for triggering the bonus mode game, the gaming machine displays an object image corresponding to a character CC 4  on the display panel  73  and renders an effect that the character appears the open sliding doors  71  and  72 . The character CC 4  may be, for example, Ali Baba. 
     Next, the chance types for bonus probability are described with reference to  FIG. 98  to  FIG. 100 . The chance types for bonus probability may include various chance types according to various embodiments. 
       FIG. 98  to  FIG. 100  show examples of a chance type for bonus probability in a chance mode game according to an embodiment of the present invention. 
     Chance Type 1 for Bonus Probability 
     When the chance type 1 for bonus probability is determined, a controller of a gaming machine displays an object image corresponding to a particular image CC 5  on a display panel  50  of a secondary display  70 , and renders an effect that a particular image CC 5  comes from the inside, as shown in  FIG. 98 . The size of the particular image CC 5  represents a bonus probability that is randomly determined by the gaming machine. The size of the particular image CC 5  may be proportional to the bonus probability. The particular image CC 5  may be, for example, a jewel image or an image for a particular symbol (e.g., “CHANCE”). The determined bonus probability, i.e., the determined symbol code determination table is applied to the chance round. 
     Chance Type 2 for Bonus Probability 
     When the chance type 2 for bonus probability is determined, a controller closes left and right sliding doors  71  and  72 , and renders an effect that an object image corresponding to particular images CC 6  are displayed on a display panel  73  of a secondary display  70  and appears through holes  74   a  to  74   e  of the sliding doors  71  and  72 , as shown in  FIG. 99 . The number of the particular images CC 6  represents a bonus probability that is randomly determined by the gaming machine. The number of the particular images CC 6  may be proportional to the bonus probability. The particular image may be, for example, a jewel image or an image for a particular symbol (e.g., “CHANCE”). 
     Chance Type 3 for Bonus Probability 
     When the chance type 3 for bonus probability is determined, a controller renders an effect that characters CC 7  pass carrying jewels with them on a display panel  73 , as shown in  FIG. 100 . The number of the passing characters CC 7  represents a bonus probability that is randomly determined by the gaming machine. The number of the passing characters may be proportional to the bonus probability. The characters CC 7  may be, for example, thieves in the story of “Ali Baba and the Forty Thieves.” 
     As described above, the gaming machine according to the above embodiment can visually show a bonus probability in a chance round. Accordingly, the player can play the game with the expectation that the bonus mode game will be triggered with the shown bonus probability. Further, the player can continuously play the game to trigger the chance mode game in which the bonus mode game can be triggered with a high probability. 
     Next, the chance types for additional benefit are described with reference to  FIG. 101  and  FIG. 102 . The chance types for additional benefit may include various chance types according to various embodiments. 
       FIG. 101  and  FIG. 102  show examples of a chance type for additional benefit in a chance mode game according to an embodiment of the present invention. 
     Chance Type 1 for Additional Benefit 
     When the chance type 1 for additional benefit is determined, a controller of a gaming machine displays an object image CC 8  corresponding to a character on a display panel  73  of a secondary display  70 , and renders an effect that the character CC 8  is defeated and a fixed payout is provided, as shown in  FIG. 101 . The character CC 8  may be, for example, a thief in the story of “Ali Baba and the Forty Thieves.” The gaming machine awards to the player credits corresponding to the fixed payout as well as, if any, credits corresponding to a winning combination. 
     Chance Type 2 for Additional Benefit 
     When the chance type 2 for additional benefit is determined, the controller displays an object image CC 9  corresponding to a treasure chest on a display panel  73  of a secondary display  70 , and renders an effect that a payout ratio comes from the treasure chest CC 9  is provided, as shown in  FIG. 102 . The gaming machine multiplies credits corresponding to a winning combination by the payout ratio, and provides the multiplied credits to the player. 
     As described above, the gaming machine according to the above embodiment can provide the player with the additional benefit along with a visual effect in a chance round. Accordingly, the player can continuously play the game to trigger the chance mode game that can receive the additional benefit. 
     Next, the chance types for event are described with reference to  FIG. 103  to  FIG. 105 . The chance types for event may include various chance types according to various embodiments. 
       FIG. 103  to  FIG. 105  show examples of a chance type for event in a chance mode game according to an embodiment of the present invention. 
     In the chance types for event, a gaming machine starts opens the sliding doors  71  and  72  halfway, by fully opening only one of the left and right sliding doors  71  and  72 . It is assumed that the left sliding door  71  is opened and the right sliding door  72  is closed when reels  31   a  to  31   e  starts to spin. 
     Chance Type 1 for Event 
     When the chance type 1 for event is determined, a controller of a gaming machine displays an object image corresponding to a character CC 10  on a display panel  73  of a secondary display  70 , and renders an effect that the character CC 10  appears through the open sliding door  71  while reels  31   a  to  31   e  are spinning, as shown in  FIG. 103 . Subsequently, an effect that the character CC 10  tries to carry a treasure pouch CC 11  or CC 12  out of the closed sliding door  72  is rendered. Each time the character CC 10  carries the treasure pouch CC 11  or CC 12  out of the closed sliding door  72 , the payer obtains a payout from the treasure pouch CC 11  or CC 12 . Further, the open sliding door  71  is gradually closed, and the chance round ends when the sliding door  71  is closed. The character CC 10  may be, for example, Ali Baba. 
     Chance Type 2 for Event 
     When the chance type 2 for event is determined, a controller displays an object image corresponding to a character CC 13  on a display panel  73  of a secondary display  70 , and renders an effect that the character CC 13  appears through the open sliding door  71  while reels  31   a  to  31   e  are spinning. Subsequently, an effect that the character CC 13  tries to pull something out of the closed sliding door  72  is rendered, as shown in  FIG. 104 . The right sliding door  72  is opened while the character CC  13  pulls something out of the right sliding door  72 . When the treasure pouch CC  14  appears through the right sliding door  72  on the display panel  73 , the payer obtains a payout from the treasure pouch C 14 . However, if other character appears through the right sliding door  72 , the chance round is ended. The other character may be, for example, a thief. 
     Chance Type 3 for Event 
     When the chance type 3 for event is determined, a controller displays an object image corresponding to a character CC 15  on a display panel  73  of a secondary display  70 , and renders an effect that the character CC 15  appears through the open sliding door  71  while reels  31   a  to  31   e  are spinning. Subsequently, an effect that the character CC 15  tries to push the closed sliding door  72  such that rocks on the closed sliding doors crumble and holes  74   d  and  74   e  appear is rendered, as shown in  FIG. 105 . An effect that a female character or a male character is shown through the holes is rendered. When the character CC 15  pushes and opens the sliding door  72 , an object image corresponding CC 16  to the female character or the male character is displayed on the display panel  73 . If the female character appears, the gaming machine triggers a bonus mode game. If the male character appears, the gaming machine does not trigger a bonus mode game and ends the event rendering pattern. For example, the female character may be Morgiana, and the male character may be a thief. 
     As described above, the gaming machine according to the present embodiment can visually show an event in a chance round and provide a benefit to the player according to a result of the event. Accordingly, the player can play the game with the expectation that the additional benefit can be provided in the chance round. Further, the player can continuously play the game to trigger the chance mode game that can receive the additional benefit. 
     Gaming Method 
     Hereinafter, a gaming method in a gaming machine according to embodiments of the present invention will be described in detail with reference to  FIG. 106  to  FIG. 113 . 
       FIG. 106  is a flowchart of a normal mode game process according to an embodiment of the present invention. 
     According to an embodiment of the present invention, a controller of the gaming machine performs the normal mode game process shown in  FIG. 106  to execute the normal mode game. 
     Referring to  FIG. 106 , in the normal mode game process, the controller determines whether credits are bet by a player (S 105 ). When the credits are not bet (S 105 : NO), the step S 2105  is re-executed and the gaming machine is under a standby state until credits are bet. 
     When the credits are bet (S 105 : YES), the player&#39;s credit value is reduced by an amount of the betted credits (S 110 ). If the amount of betted credits is larger than the credit value, the process (S 110 ) of reducing the credit value is not carried out and the control performs the step S 115 . The controller determines whether a game is started by the player. The player may start the game by pressing a START button ( 54  of  FIG. 8 ). If the game is not started (S 115 : NO), the normal mode game process is returned to the step S 105 . Further, if the game is not started (for example, if the game is not started and an instruction to end the game is input), the subtraction result from the step S 110  is canceled. 
     If the game is started (S 115 : YES), the controller executes a symbol determining process (S 120 ). In other words, the controller generates a random number for each of reels  31   a  to  31   e , and determines symbols to be appeared on each of the reels  110  to  31   e  based on the generated random number and a symbol code determination table for the normal mode game. Accordingly, symbols to be stopped on each pay line are determined. Further, the controller starts to spin the reels  31   a  to  31   e.    
     When a certain time period elapses after spinning of the reels  31   a  to  31   e  is started, the controller stops each of the reels  31   a  to  31   e  to locate the determined symbols on a symbol matrix of the reels  31   a  to  31   e  (S 125 ). That is, the symbols are rearranged on the symbol matrix. On the basis of the combination of symbols stopped on the pay lines, the controller determines whether the combination of symbols is a winning combination or not (S 130 ). When the combination is the winning combination (S 130 : YES), a payout process is executed (S 135 ). In other words, if the combination is the winning combination, the controller calculates the amount of credits to be paid out according to a type of the winning combination. 
     When the payout process in the step S 135  is executed or the combination is not the winning combination (S 130 : NO), the controller continues to determine whether the rearranged symbols satisfy a triggering condition of a chance mode game or a bonus mode game (S 140 ). The controller may determine that the chance mode game is triggered when a special symbol (“CHANCE”) is stopped on a middle row of the third reel  31   c . The controller may determine that the bonus mode game is triggered when three or more scatter symbols (“BONUS”) are rearranged on the reels  31   a  to  31   e.    
     When the rearranged symbols satisfy the triggering condition of the chance mode game (S 140 : YES), the controller triggers the chance mode game and executes a chance mode game process (S 145 ). In this case, the gaming machine may render a rendering pattern for notifying the trigger of the chance mode game, using sliding doors  71  and  72  and a display panel  73  of a secondary display. In the chance mode game process, the chance mode game with a higher bonus probability than the normal mode game is executed. 
     When the rearranged symbols satisfy the triggering condition of the bonus mode game (S 140 : YES), the controller triggers the bonus mode game and executes a bonus mode game process (S 150 ). In this case, the gaming machine may render a rendering pattern for notifying the trigger of the bonus mode game, using sliding doors  71  and  72  and a display panel  73  of a secondary display  70 . In the bonus mode game process, the bonus mode game including a plurality of free rounds is executed. If the triggering game is not satisfied (S 140 : NO), the process of the step S 105  is executed. 
       FIG. 107  and  FIG. 108  are a flowchart of a normal mode game process according to another embodiment of the present invention. 
     According to another embodiment of the present invention, a controller of the gaming machine renders a rendering pattern using a display panel  73  and sliding doors  71  and  72  of a secondary display  70  when executing the normal mode game. 
     Referring to  FIG. 107 , the controller opens left and right sliding doors  71  and  72  in the secondary display  70  when the normal mode game is started (S 205 ). The controller determines whether the credits are bet by the player (S 210 : YES), and reduces the player&#39;s credit value by an amount of the betted credits (S 215 ). If the chance mode game is started (S 220 ), the controller randomly determines symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) based on a symbol code determination table (S 225 ). The controller selects a rendering pattern data corresponding to a type of the game result among a plurality of rendering pattern data (S 230 ), and starts to spin reels  31   a  to  31   e . Next, the controller displays an image according to a display data of the selected rendering pattern data on a display panel  73  of the second display  70  while the reels  31   a  to  31   e  are spinning (S 235 ). Further, the controller controls the sliding doors  71  and  72  according to a control data of the selected rendering pattern data while the reels  31   a  to  31   e  are spinning (S 240 ). 
     Next, the controller stops each of the reels  31   a  to  31   e  to locate the symbols corresponding to the game result on a symbol matrix of the reels  31   a  to  31   e  (S 245 ). Referring to  FIG. 108 , the controller determines whether the combination of symbols is a winning combination or not (S 250 ). Further, the controller determines whether an additional benefit is provided according to a result of the determined rendering pattern (S 255 ). If the combination is the winning combination (S 250 : YES) and the additional benefit is provided (S 255 : YES), the controller combines the additional benefit with a payout (credits) according to the winning combination and awards the combined payout to the player (S 260 ). For example, the additional benefit may be a payout ratio and the combined payout may be the payout according to the winning combination multiplied by the payout ratio. If the combination is the winning combination (S 250 : YES) and the additional payout is not provided (S 255 : NO), the controller awards the credits according to the winning combination to the player (S 265 ). 
     When the payout process in the step S 260  or S 265  is executed or the combination is not the winning combination (S 250 : NO), the controller continues to determine whether the rearranged symbols satisfy a triggering condition of a chance mode game or a bonus mode game (S 270 ). When the rearranged symbols satisfy the triggering condition of the chance mode game (S 270 : YES), the controller triggers the chance mode game and executes a chance mode game process (S 275 ). When the rearranged symbols satisfy the triggering condition of the bonus mode game (S 270 : YES), the controller triggers the bonus mode game and executes a bonus mode game process (S 280 ). If the triggering condition is not satisfied (S 270 : NO), the process of the step S 205  is executed. 
       FIG. 109  and  FIG. 110  are a flowchart of a chance mode game process according to an embodiment of the present invention. 
     According to an embodiment of the present invention, a controller of the gaming machine performs the chance mode game process shown in  FIG. 109  and  FIG. 110  to execute the chance mode game. 
     Referring to  FIG. 109 , the controller closes left and right sliding doors  71  and  72  in a secondary display  70  when the chance mode game is triggered (S 305 ). When a chance round of the chance mode game is started (S 310 ), the controller randomly determines symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) based on a symbol code determination table for the chance mode game (S 315 ), and determines a chance type corresponding to the game result among various chance types (S 320 ). The controller may randomly determine the symbol code determination table among a plurality of symbol code determination tables for the chance mode game. Each symbol code determination table for the chance mode game may have a higher bonus probability than a default symbol code determination table for the normal mode game. The chance round may be started automatically or an input of the player. 
     The controller selects a rendering pattern data corresponding to the selected chance type among a plurality of rendering pattern data for the chance mode game (S 325 ), and starts to spin reels  31   a  to  31   e . Next, the controller displays an image according to a display data of the selected rendering pattern data on a display panel  73  of the second display  70  while the reels  31   a  to  31   e  are spinning (S 330 ). Further, the controller controls the sliding doors  71  and  72  according to a control data of the selected rendering pattern data while the reels  31   a  to  31   e  are spinning (S 335 ). 
     Next, the controller stops each of the reels  31   a  to  31   e  to locate the determined symbols on a symbol matrix of the reels  31   a  to  31   e  (S 340 ). Referring to  FIG. 110 , the controller determines whether the combination of symbols is a winning combination or not (S 345 ). Further, the controller determines whether an additional benefit is provided according to a result of the determined rendering pattern (S 345 ). If the combination is the winning combination (S 345 : YES) and the additional benefit is provided (S 350 : YES), the controller combines the additional benefit with a payout according to the winning combination and awards the combined payout to the player (S 355 ). If the combination is the winning combination (S 345 : YES) and the additional benefit is not provided (S 350 : NO), the controller awards the credits according to the winning combination to the player (S 360 ). If the combination is not the winning combination (S 345 : NO) and the additional benefit is provided (S 350 : YES), the controller awards the additional benefit to the player (S 365 ). 
     When the payout process in the step S 355 , S 360  or S 365  is executed or the combination is not the winning combination (S 345 : NO), the controller increments the number of executed chance round by 1 (S 370 ). Further, the controller continues to determine whether an ending condition of the chance mode game is satisfied (S 375  or S 385 ). The controller determines whether the rearranged symbols satisfy a triggering condition of a bonus mode game (S 375 ). When the rearranged symbols satisfy the triggering condition of the bonus mode game (S 375 : YES), the controller ends the chance mode game and executes a bonus mode game process (S 380 ). If the triggering condition is not satisfied (S 375 : NO), the controller determines whether the number of executed chance rounds is less than a threshold (S 385 ). When the number of executed chance rounds is less than the threshold (S 385 : YES), the controller starts a next chance round in the step S 310 . When the number of executed chance rounds is equal to the threshold (S 385 : NO), the controller ends the chance mode game and returns to the normal mode game (S 390 ). 
       FIG. 111  and  FIG. 112  are a flowchart of a chance mode game process according to another embodiment of the present invention. 
     Referring to  FIG. 111 , the controller closes left and right sliding doors  71  and  72  in a secondary display  70  when the chance mode game is triggered (S 405 ). When a chance round of the chance mode game is started (S 410 ), the controller randomly determines a chance type to be executed in a current chance round among a plurality of chance types (S 415 ). The chance round may be started automatically or an input of the player. Further, the controller selects a rendering pattern data corresponding to the determined chance type among a plurality of rendering pattern data for the chance mode game (S 420 ). Further, the controller selects a symbol code determination table corresponding to the determined chance type among a plurality of symbol code determination tables for the chance mode game (S 425 ). Each symbol code determination table for the chance mode game has a higher bonus probability than a default symbol code determination table for the normal mode game. 
     Further, the controller starts to spin reels  31   a  to  31   e  and randomly determines symbols to be rearranged on reels  31   a  to  31   e  (i.e., a game result) based on the selected symbol code determination table for the chance mode game (S 430 ). Further, the controller displays an image according to a display data of the selected rendering pattern data on a display panel  73  of the second display  70  while the reels  31   a  to  31   e  are spinning (S 435 ). Further, the controller controls the sliding doors  71  and  72  according to a control data of the selected rendering pattern data while the reels  31   a  to  31   e  are spinning (S 440 ). 
     Next, the controller stops each of the reels  31   a  to  31   e  to locate the symbols corresponding to the game result on a symbol matrix of the reels  31   a  to  31   e  (S 445 ). Referring to  FIG. 112 , the controller determines whether the combination of symbols is a winning combination or not (S 450 ). Further, the controller determines whether an additional benefit is provided according to a result of the determined rendering pattern (S 455 ). If the combination is the winning combination (S 450 : YES) and the additional benefit is provided (S 455 : YES), the controller combines the additional benefit with a payout according to the winning combination and awards the combined payout to the player (S 460 ). If the combination is the winning combination (S 450 : YES) and the additional benefit is not provided (S 455 : NO), the controller awards the credits according to the winning combination to the player (S 465 ). If the combination is not the winning combination (S 450 : NO) and the additional benefit is provided (S 455 : YES), the controller awards the additional benefit to the player (S 470 ). 
     When the payout process in the step S 460 , S 465  or S 470  is executed or the combination is not the winning combination (S 450 : NO), the controller increments the number of executed chance round by 1 (S 475 ). Further, the controller continues to determine whether an ending condition of the chance mode game is satisfied (S 480  or S 490 ). The controller determines whether the rearranged symbols satisfy a triggering condition of a bonus mode game (S 480 ). When the rearranged symbols satisfy the triggering condition of the bonus mode game (S 480 : YES), the controller ends the chance mode game and executes a bonus mode game process (S 485 ). If the triggering condition is not satisfied (S 480 : NO), the controller determines whether the number of executed chance rounds is less than a threshold (S 490 ). When the number of executed chance rounds is less than the threshold (S 490 : YES), the controller starts a next chance round in the step S 410 . When the number of executed chance rounds is equal to the threshold (S 490 : NO), the controller ends the chance mode game and returns to the normal mode game (S 495 ). 
       FIG. 113  is a flowchart of a bonus mode game process according to an embodiment of the present invention. 
     According to an embodiment of the present invention, a controller of the gaming machine performs the bonus mode game process shown in  FIG. 113  to execute the bonus mode game. 
     Referring to  FIG. 113 , the controller closes left and right sliding doors  71  and  72  in a secondary display  70  when the bonus mode game is triggered (S 505 ). The controller randomly determines a bonus type to be executed in the bonus mode game among a plurality of bonus types (S 510 ). The controller selects a rendering pattern data corresponding to the determined bonus type among a plurality of rendering pattern data for the bonus mode game (S 515 ). The controller selects a symbol code determination table corresponding to the determined bonus type among a plurality of symbol code determination tables for the bonus mode game (S 520 ). Further, the controller opens left and right sliding doors  71  and  72  and displays an image for notifying the determined bonus type on a display panel  73  of the secondary display  70  (S 525 ). In this case, the controller may open the sliding doors  71  and  72  fully. 
     Next, the controller starts a free round of the bonus mode game according to the determined bonus type (S 530 ). The free round may be started automatically or an input of the player. Further, the controller starts to spin reels  31   a  to  31   e , and executes a symbol determining process based on the selected symbol code determination table (S 535 ). Further, the controller renders a rendering pattern according to the rendering pattern data corresponding to the determined bonus type using the display panel  73  and the reels  31   a  to  31   e  (S 540 ). The controller may render any one of the rendering patterns exemplified in  FIG. 38  to  FIG. 47 . 
     Next, the controller determines a benefit to be awarded to the player (S 545 ), and provides the benefit to the player (S 550 ). For example, the controller may determine the benefit (i.e., credits) according to “WILD” symbols and the other symbols arranged on the reels  31   a  to  31   e  in the bonus type 1, determine the benefit (i.e., credits) according to the defeated character and the symbols arranged on the reels  31   a  to  31   e  in the bonus type 2, and determine the benefit according to an event of a cell at which the character arrives by the number of the scatter symbols (“BONUS”). 
     Further, the controller increments the number of executed free round by 1 (S 555 ), and determines whether an ending condition of the bonus mode game is satisfied (S 560 ). The controller determines whether the number of executed free rounds is less than a threshold (S 560 ). When the number of executed chance rounds is less than the threshold (S 560 : YES), the controller starts a next free round in the step S 530 . When the number of executed free rounds is equal to the threshold (S 560 : NO), the controller ends the bonus mode game and returns to the normal mode game (S 565 ). 
     Embodiments of the present invention can also be embodied as a computer readable program on a computer-readable recording medium. The computer readable recording medium is any data storage device that can store data that can be read thereafter by a computer. Examples of the computer readable recording medium include ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. The computer readable recording medium can also be distributed over a network coupled computer system so that the computer readable code is stored and executed in a distributed fashion. 
     While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.