Patent Publication Number: US-6988731-B2

Title: Symbol display device for game machine

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a symbol display device mounted in a game machine, such as a roulette game machine. The symbol display device displays the win or the loss of the game by rotating and stopping rotational members having predetermined symbols. 
   2. Description Related to the Prior Art 
   A symbol display device mounted in a slot game machine or a Pachinko game machine generally uses reels arranged in lines or in a matrix. Some symbol display devices use a liquid crystal display to simulate rotation of the reels. For instance, Japanese Patent Laid-Open Publication (JP-A) No. 2000-116843 describes a symbol display device that determines the win or lose in accordance with combinations of the symbols displayed on a rotary reel (first display) having a transparent window and a second display inside the first display. The second display is a liquid crystal display panel or another rotary reel having a diameter different from that of the first display. Additionally, U.S. Pat. No. 5,152,529 describes another example of the symbol display device that uses double structured reel composed of an outer reel having an opening and an inner reel disposed inside the outer reel. The game machines with the symbol display devices described above may change the symbols twice and provide a variety of symbol display patterns. 
   However, since the second display provided inside the first display is validated only when the transparent window or the opening stop on a predetermined winning line, which is not always happened, it is not possible to use the second display effectively. Accordingly, such symbol display devices have limitations to provide various display patterns of symbols. In order to provide various display patterns of symbols by use of the second display devices in the outer reels, all of the outer reels need to have transparent windows or the openings. 
   The symbol display device, described in Japanese Utility-Model Publication No. H07-22301, has three concentric rotary disks. The player wins if a predetermined combination of the symbols on the rotary disks is displayed in a radial direction. Such symbol display device may be more compact than that having mechanical reels arranged in lines or in a matrix. Such symbol display device, however, has insufficient display patterns in a game because a player can observe all the symbols. Thus, sufficient appeal to a player is not expected. 
   In order to solve the above problems, a symbol display device, described in JP-A H06-327807, has a first display device having a round rotator, for example, and a second display device having mechanical reels disposed inside of the round rotator. When a player plays a game machine that mounts such symbol display device, the first display device executes roulette game, and the second display device is operated if the player wins in the roulette game. If the player wins in the slot game executed by the second display device, the points gained by winning in the slot game is added to the points gained in the roulette game, so as to encourage the player&#39;s expectation to win. Although playing different games continuously may prevent a player from being dull, a game machine is not organized as the first and the second display devices are less associated with each other. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a symbol display device for a game machine that provides various display patterns associated with the game result. 
   Another object of the present invention is to provide a symbol display device that improves the appeal effect to a player. 
   In order to achieve the above objects, the symbol display device of the present invention comprises plural concentric main display units having display parts, and a sub display unit for displaying symbols in motion and/or a static symbol behind at least one of the light-penetrate area. The sub display unit is mounted on a rotary member provided concentrically with the main display units. The main display units and said rotary member rotate separately. 
   In a preferred embodiment, the display part is composed of at least one symbol area in which a symbol is provided and at least one transparent non-symbol area. The light-penetrate area is one of the non-symbol area, a transparent area inside the symbol, or a transparent area outside the symbol in the symbol area. 
   The main display unit may have at least one transparent part inside or outside of the display part. When the sub display unit is stopped in an overlap area where the light-penetrate area of one of the main display units is overlapped with the transparent parts of other main display units, the sub display unit displays symbols in motion and/or a static symbol behind the overlap area. 
   The sub display unit may display symbols in motion and/or a static symbol, when the light-penetrate areas of the main display units are stopped and arranged in line. In that case, the drive mechanism rotates the rotary member to the position where the sub display unit is overlapped with the light-penetrate areas arranged in line. 
   It is possible to overlap the symbol of the sub display unit with the symbol of the main display unit so as to form a single composite symbol. 
   According to the present invention, since the display patterns of two different games by the main display units and the sub display unit are associated with each other, it is possible to improve the appeal effect to a player. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One with ordinary skill in the art would easily understand the above-described objects and advantages of the present invention when the following detailed description is read with reference to the drawings attached hereto. 
       FIG. 1  is a front perspective view of a slot machine in which a symbol display device of the present invention is mounted; 
       FIG. 2  is a perspective view of the symbol display device; 
       FIGS. 3 ,  4  and  5  are front views illustrating an example of a first, a second and a third display plates, respectively; 
       FIG. 6  is a front view illustrating an example of a symbol sheet attached to a periphery of a sub reel; 
       FIG. 7 and 8  are partial cross sections illustrating a composition of the symbols display device; 
       FIG. 9  is a functional block view illustrating a part of an electrical composition of the slot machine; 
       FIG. 10  is a flow chart showing the process of a sub game; 
       FIG. 11  is a front view illustrating an example of a winning symbol combination of first-third display parts; 
       FIG. 12  is a front view illustrating an example of a losing symbol combination of the first-third display parts; 
       FIG. 13  is a front view illustrating an example wherein blank symbols are arranged in line on a winning line; 
       FIG. 14  is a front view illustrating an example wherein a reel mounting plate is rotated to shift the sub reel behind the blank symbols; 
       FIG. 15  is a front view illustrating an example wherein a winning symbol is displayed when the sub reel stops; 
       FIG. 16  is a front view illustrating an example wherein a losing symbol is displayed when the sub reel stops; 
       FIG. 17  is a front view illustrating an example wherein a re-rotation symbol is displayed when the sub reel stops; 
       FIG. 18  is a front view illustrating an example wherein the sub reel is displayed behind the second display part; 
       FIG. 19  is a front view illustrating an example wherein the blank symbols and the losing symbol stop in line on a winning line when the first-third display plates stop rotating. 
       FIG. 20  is a front view illustrating an example wherein the symbols of the sub reel and the second display part compose a composite symbol when the sub reel stops; 
       FIG. 21  is a partial cross section illustrating plural reel mounting plates on which the sub reels are mounted; and 
       FIG. 22  is a front view illustrating an example of a Pachinko game machine wherein the symbol display device is mounted. 
   

   PREFERRED EMBODIMENTS OF THE INVENTION 
   As shown in  FIG. 1 , a slot game machine  2  has a front panel  11 , wherein display windows  10  are arranged in a matrix of  3  lines and  3  rows. Reel units (not shown) are disposed behind the display windows  10  of the front panel  11 , and three symbols in lengthwise direction disposed on each reel  12  may be observed through the display window  10  when reel  12  of the reel unit stops rotating. The result of the game (win or loss) is determined in accordance with symbol combinations on eight winning lines running vertically, horizontally and diagonally, or a symbol stopped in the display window  10 . Indicators  13  are provided in the front panel  11  to indicate the winning lines. A coin slot  14 , an operation panel  15 , a coin tray  16  are provided below the front panel  11 , while a start lever  17  is provided at the lateral side of the slot game machine  2 . 
   The operation panel  15  has buttons such as a bet button  18  and a payout button. When the bet button  18  is operated to select the number of coins to be bet, the winning line to be validated is determined. For example, one winning line is validated when one coin is bet, and eight winning lines are validated in maximum betting. Then, the game is started by the operation of the start lever  17 , and each reel automatically stops at stop positions to display the symbols determined in accordance with random numbers sampled in advance. If a winning symbol combination stops on the winning line or a winning symbol is displayed, dividend coins are dispensed to the coin tray  16 . The amount of the dividend coins is determined based on the type of the win. 
   A symbol display device  20  mounted in the slot game machine  2  is disposed above the front panel  11 . The symbol display device  20  executes the roulette game (sub game) if the player wins in the slot game (main game) using the reels. As shown in  FIG. 2 , the symbol display device  20  is a unit composed of first, second and third display plates  21 ,  22  and  23 , a reel mounting plate (rotator)  24 , a sub reel  25 , a display driver  26  and a support plate  27 . The symbol display device  20  is covered with a front door  30  (see FIG.  1 ). Besides the sub game device, the symbol display device  20  may be utilized as means to determine the amount of the dividend coins, for instance. 
   As shown in from  FIG. 3  to  FIG. 5 , each of the first, second and third display plates  21 ,  22  and  23  are respectively composed of transparent circular plate having the same diameter. A first, second and third display parts  21   a ,  22   a  and  23   a  are provided in the first, second and third display plates  21 ,  22  and  23 , respectively. The first display part  21   a  in the first display plate  21  is the smallest while the third display part  23   a  in the third display plate  23  is the largest. The outer diameter D 1  of the first display part  21   a  has the same length as the inner diameter D 2  of the second display part  22   a , while the outer diameter D 3  of the second display part  22   a  has the same length as the inner diameter D 4  of the third display part  23   a.    
   The second display plate  22  is disposed in front of the third display plate  23 , and the first display plate  21  is disposed in front of the second display plate  22 . The third display plate  23  is disposed in front of a sub reel  25 . The first, second and third display plates  21 ,  22  and  23  are concentrically attached to the display driver  26 . Note that the display part  22   a  of the second display plate  22  is observable through the transparent part  21   b  of the first display plate  21 , and the display part  23   a  of the third display plate  23  is observable through the transparent part  21   b  of the first display plate  21  and the transparent part  22   b  of the second display plate  22 . Thereby, the first, second and third display parts  21   a ,  22   a  and  23   a  are disposed concentrically and adjacent to each other (see FIG.  11 ). The first, second and third display plates  21 ,  22  and  23  operate as main display means. 
   Each of the display parts  21   a ,  22   a  and  23   a  is divided into plural parts corresponding to the number of the disposed symbols. For example, each display is divided into twelve parts for number symbols of “1” to “10” and two blank symbols. Note that the blank symbol is a cell having no symbol. The blank symbols  31   a ,  31   b  are disposed on the first display part  21   a , the blank symbols  31   c ,  31   d  are disposed on the second display part  22   a , and the blank symbols  31   e ,  31   f  are disposed on the third display part  23   a . The blank symbols  31   a  to  31   f  are transparent so that at least one symbol on the display part behind the blank symbol is observable through the blank symbol. Twelve symbols on the first, second and third display plate parts  21   a ,  22   a  and  23   a , form a winning line in radial directions (indicated by numerals from  120  to  131  in FIG.  11 ). Note that the first-third display parts  21   a ,  22   a  and  23   a  may have other symbol type than the number in the above embodiment. Examples of other symbol type are marks, signs, color and pictures. Arrangement and the number of the symbols including the blank symbols on the display parts  21   a ,  22   a  and  23   a  are not limited in the embodiment shown in  FIGS. 3 ,  4  and  5 , but may be determined appropriately. Furthermore, though borderlines between the blank symbols and the transparent parts are shown by chain double-dashed lines, it is possible to omit the borderlines. 
   The reel mounting plate  24  is disposed behind and concentrically with the first, second and third display plates  21 ,  22  and  23 . The sub reel  25  is mounted on the reel mounting plate  24 . The reel mounting plate  24  is rotated when the blank symbols of first, second and third display parts  21   a ,  22   a  and  23   a  is arranged in line on any of winning lines  120  to  131  when the first-third displays  21 ,  22  and  23  stop rotating. In addition, the reel mounting plate  24  shifts the sub reel  25  behind the blank symbols on the winning line. 
   The sub reel  25  is disposed behind the first, second and third displays  21 ,  22  and  23  such that the axial direction coincides the radial direction of the reel mounting plate  24  and crosses the first, second and third display parts  21   a ,  22   a  and  23   a . As shown in  FIG. 6 , a symbol sheet  32 , whereon plural symbols  34 ,  35  and  36  and the blank symbols  37  are disposed alternately, is attached to the sub reel  25 . The symbols  34 ,  35  and  36  respectively represent the win, the loss and re-rotation of the first, second and third display plates  21 ,  22  and  23 . Although dotted lines are used as the borderlines between the symbols  34  to  36  and the blank symbols  37  so as to distinguish them from each other, it is possible to omit the borderlines. 
   The sub reel  25  normally displays the blank symbol  37  when it is not rotating. If the blank symbols of the display plates  21 ,  22  and  23  are arranged in line, the reel mounting plate  24  starts rotating and shifts the sub reel  25  to the position behind the blank symbols. Then, the sub reel  25  starts rotating and stops to display a symbol representing the win, the loss or the re-rotation of the display plates  21 ,  22  and  23  through the blank symbols. Thus, the sub reel  25  functions as sub display means. 
   As shown in  FIGS. 7 and 8 , the display driver  26  is provided with first, second, third and fourth rotary shafts  40 ,  41 ,  42  and  43  and first, second, third, fourth and fifth drive motors  44 ,  45 ,  46 ,  47  and  48 . The rotary shafts except the first rotary shaft  40  have tubular shapes. The first to third displays  21 ,  22  and  23  and the reel mounting plate  24  are firmly screwed to first, second, third and fourth flanges  49 ,  50 ,  51  and  52  that are fixed to the one ends of the first to fourth rotary shafts  40 ,  41 .  42  and  43 , respectively. A portion of the first flange  49  is fitted into a concave part  50   a  formed in the second flange  50 . A portion of the second flange  50  is fitted into a concave part  51   a  formed in the third flange  51 . 
   The first rotary shaft  40  is inserted into the hollow part of the second rotary shaft  41  and determined its position by bearings (not shown) attached to both ends of the second rotary shaft  41 . Thereby, the first rotary shaft  40  and the second rotary shaft  41  are held concentrically, so are the first display plate  21  and the second display plate  22 . Similarly, the second rotary shaft  41  is inserted into the hollow part of the third rotary shaft  42  and determined its position by the bearings (not shown) attached to both ends of the third rotary shaft  42 . Thereby, the second rotary shaft  41  and the third rotary shaft  42  are held concentrically, so are the second display plate  22  and the third display plate  23 . The third rotary shaft  42  is inserted into the hollow part of the fourth rotary shaft  43  and determined its position by the bearings (not shown) attached to both ends of the fourth rotary shaft  43 . Thereby, the third rotary shaft  42  and the fourth rotary shaft  43  are held concentrically, so are the third display plate  23  and the reel mounting plate  24 . 
   Accordingly, the first-fourth rotary shafts  40 ,  41 ,  42 , and  43  are held concentrically, and the first-third displays  21 ,  22  and  23  and the reel mounting plate  24  are held concentrically as well. The fourth rotary shaft  43  is fixed to the support plate  27  by bearing members  54  and  55 . Note that the reference numerical  54   a  and  55   a  represent bearings to enable smooth rotation of the fourth rotary shaft  43 . Gears  60 ,  61 ,  62  and  63  are respectively fixed to the other ends of the first to fourth rotary shafts  40 ,  41 ,  42  and  43 . 
   Each of the first to fourth drive motors  44 ,  45 ,  46 , and  47  is a stepping motor driven by drive pulses, and rotates the first-third displays  21 ,  22  and  23  and the reel mounting plate  24 . Gears  65 ,  66 ,  67 , and  68  fixed to the drive shafts of corresponding drive motors are respectively in mesh with the gears  60 ,  61 ,  62  and  63  of the first to fourth rotary shafts  40 ,  41 ,  42 , and  43 . Drive force of the first to fourth drive motors  44 ,  45 ,  46  and  47  is transmitted to the first to fourth rotary shafts  40 ,  41 ,  42  and  43  so as to rotate the first to third displays  21 ,  22  and  23  and the reel mounting plate  24  individually. Each of the first to fourth drive motors  44 ,  45 ,  46  and  47  is respectively held by brackets  70 ,  71 ,  72  and  73  and fixed to the rear side of the support plate  27 . 
   Each of the gears  60 ,  61 ,  62  and  63  is provided with position detecting segments  75 ,  76 ,  77  and  78  to indicate standard positions of the first to third displays  21 ,  22  and  23  and the reel mounting plate  24 . Photo interrupters  80  mounted on each drive motors detects the position detecting segments  75 ,  76 ,  77  and  78  so as to detect that the first to fourth rotary shafts  40 ,  41 ,  42  and  43  rotate by 360 degrees. 
   Similarly, the photo interrupter  80  detects the position detecting segment  78  to detect that the sub reel  25  mounted on the reel mounting plate  24  makes one rotation. Note that the photo interrupters mounted to the drive motors  46  and  47  are not shown to avoid complication of the drawing. Note that, in the present embodiment, the blank symbols  31   a ,  31   c  and  31   e  on the first to third display parts  21   a ,  22   a  and  23   a  are respectively on a standard line  88  when the position detecting segments  75 ,  76  and  77  are detected by each photo interrupter  80  (see  FIGS. 3 ,  4  and  5 ). The sub reel  25  is on the standard line  88  when the position detecting segment  78  is detected by the photo interrupter  80  (see FIG.  11 ). 
   The fifth drive motor  48  is fixed to the reel mounting plate  24  by brackets  81  and  82 . The sub reel  25  is fixed to the drive shaft of the fifth drive motor  48  by a flange  83 . Thereby, drive force of the fifth drive motor  48  is transmitted to the sub reel  25 . The photo interrupter  85  detects the position detecting segment  84 , which is fixed to the flange  83 , so as to detect the rotation of the sub reel  25 . Note that, in the present embodiment, the winning symbol  34  in the sub reel  25  is displayed behind the third display plate  23  when the position detecting segment  84  is detected by the photo interrupter  85 . 
   Since the display driver  26  is fixed to the support plate  27  as one unit, the symbol display device  20  becomes small. Moreover, it is possible to improve workability, because the symbol display device  20  is easily mounted in the slot game machine  2  just by mounting the support plate  27  to a predetermined position and it improves the workability as well. Note that the composition of the display driver  26  is not limited in the above embodiment but other mechanism may be utilized. For example, a pulley and a toothed belt may be used instead of the gears. 
     FIG. 9  is a functional block diagram showing an electrical configuration of a part of the slot game machine  2  for executing roulette game. Note that an explanation and drawing of a part for executing slot game are omitted. A CPU  90  controls each section in accordance with a roulette game program stored in a ROM  91  when the player wins in the slot game. 
   The ROM  91  stores pulse number data to specify the number of the drive pulse of the drive motors  44 ,  45  and  46  to rotate the first to third display plates  21 ,  22  and  23  by predetermined angle. On receiving a game start signal from the CPU  90 , a random number generator  93  samples a random number and outputs it to a stop symbol determining section  94 . The stop symbol determining section  94  determines the stop positions for the blank symbols  31   a ,  31   c  and  31   e  in the first to third display parts  21   a ,  22   a  and  23   a  with reference to a stop position table  95 . The stop symbol determining section  94  obtains pulse number data for the first, second and third display plates  21 ,  22  and  23  from the ROM  91  such that the blank symbols  31   a ,  31   c  and  31   e  reach the respective stop positions. 
   A motor controller  96 , operated in response to the game start signal from the CPU  90 , drives the first to third drive motors  44 ,  45  and  46  through the drivers  97 ,  98  and  99 . Each of counters  100 ,  101  and  102  counts the number of each of the drive pulse inputted to the first to third drive motors  44 ,  45  and  46 . By monitoring the number of the drive pulses, the motor controller  96  specifies the positions of the blank symbols  31   a ,  31   c  and  31   e . The CPU  90  outputs a rotation stop signal to the motor controller  96  when the counters  100 ,  101  and  102  count the same pulse numbers as the ones stored in the RAM  92 . In response to the rotation stop signal, the motor controller  96  stops driving of the first to third drive motors  44 ,  45  and  46 . Note that the count values of the counters  100 ,  101  and  102  is reset respectively at the time when the photo interrupters  80  detect the position detecting segments  75 ,  76 ,  77 . 
   Referring to the count values of the counters  100 ,  101  and  102 , a stop position checking section  105  checks whether the blank symbols on the first to third display parts  21   a ,  22   a  and  23   a  stop in line on any of winning lines  120  to  131 . If the stop position checking section  105  recognizes that the blank symbols stop in line on any of the winning lines  120  to  131 , the motor controller  96  drives the fourth drive motor  47  through a driver  106 . 
   The sub reel  24  is located at a position in which the rotary shaft of the sub reel  25  is overlapped with one of the winning lines  120  to  131 . The ROM  91  stores pulse number data for the fourth drive motor  47  to rotate the sub reel  24  by predetermined angle. The motor controller  96  stops the fourth drive motor  47  when the count value of the counter  107  reaches the pulse number for the winning line with three blank symbols in line. Note that the count value of the counter  107  is reset at the time when the photo interrupter  80  detects the position detecting segment  78 . 
   Then, the motor controller  96  drives the fifth drive motor  48  through a driver  108  to start rotating the sub reel  25 . The CPU  90  reads pulse number data for the fifth drive motor  48 , stored in the ROM  91 , to rotate the sub reel  25  by predetermined angle. The motor controller  96  stops the fifth drive motor  48  when the count value counted by a counter  109  reaches the pulse number. Note that the count value of the counter  109  is reset at the time when the photo interrupter  85  detects the position detecting segment  84 . 
   A winning judging section  110  judges whether there is a winning symbol combination in a radial direction when the first to third displays  21 ,  22  and  23  stop rotation. The ROM  91  stores winning count value data for the counters  81 ,  82  and  83  at the time when winning symbol combinations are appeared on the winning lines  120  to  131 . The winning judging section  110  refers the count value of the counters  81 ,  82  and  83  to judge whether there is a winning symbol combination. In addition, the winning judging section  110  judges the win or the loss based on the count value of the counter  109  when the sub reel  25  stops rotation. If the winning judging section  110  judges that the re-rotation symbol  36  is displayed, the CPU  90  operates a random number generator  93  again. If the winning judging section  110  judges the win, the CPU  90  operates a coin dispenser  112  to dispense dividend coins, whose amount is determined based on the type of the win. 
   The function of the slot game machine, wherein the symbol display device structured as described above is mounted, is explained with reference to the flow chart of FIG.  10 . Note that the explanation about the slot game as the main game is omitted so that only the roulette game as the sub game is explained. 
   If the player wins in the main game, the CPU  90  operates the random number generator  93  to sample a random number. Based on the sampled random number, the stop symbol determining section  94  determines the stop positions of the blank symbols  31   a ,  31   c  and  31   e  and the symbol  34  of the sub reel  24 , which are temporarily stored in the RAM  92 . Simultaneously, the CPU  90  operates the motor controller  96  to rotate the first to third display plates  21 ,  22  and  23  through the first to third drive motors  44 ,  45  and  46 . 
   After the first to third display plates  21 ,  22  and  23  start rotating, the CPU  90  stops the first display plate  21  first, then the second display plate  22 , and the third display plate  23  at last, by use of a random timer section (not shown). After all of the first to third display plates  21 ,  22  and  23  stop rotating, the CPU  90  operates the stop position checking section  105  to check whether the blank symbols of the first to third display parts  21   a ,  22   a  and  23   a  stop in line on any of the winning lines from  120  to  131 . 
   If the blank symbols are not arranged in line on any of the winning lines from  120  to  131 , the CPU  90  operates the winning judging section  110  to judge (to execute winning judgment) whether the same symbols stop in line on any of the winning lines from  120  to  131 . For example, as shown in  FIG. 11 , if the symbols “1” of the first-third display parts  21   a ,  22   a  and  23   a  are arranged on the winning line  131 , the CPU  90  judges the win and drive the coin dispenser  112  to dispense the dividend coins. The amount of dispensed coins is determined based on the type of the win. If the same symbols do not stop in line on any of the winning lines from  120  to  131  as shown in  FIG. 12 , the CPU  90  judges the loss and finishes the game. 
   On the other hand, if the blank symbols  31   b ,  31   d  and  31   e  stop in line on the winning line  122 , as shown in  FIG. 13 , the CPU  90  drives the fourth drive motor  47  through the motor controller  96  to rotate the reel mounting plate  24 . Then, the CPU  90  stops the fourth drive motor  47  when the sub reel  25  reaches the position behind the blank symbols  31   b .  31   d  and  31   e , as shown in FIG.  14 . When the reel mounting plate  24  stops rotating, the motor controller  96  operates the fifth drive motor  48  to rotate the sub reel  25  and stops it after a predetermined time. When the sub reel  25  stops the rotation, one of the symbols of the sub reel  25  is displayed through the blank symbols  31   b ,  31   d  and  31   e . If the blank symbols are arranged on the same winning line as the last game, the reel mounting plate  24  rotates by 360 degrees and then stops at the same position. 
   After the sub reel  25  stops rotating, the winning judging section  110  refers the count values of the counters  100 ,  101 ,  102  and  109  to judge whether the combination of the same symbols is displayed on any of the winning lines  120  to  131  or whether the winning symbol  34  is displayed. As shown in  FIG. 15 , for example, if no combination of the same symbols stops on any of the winning lines from  120  to  131 , the player loses in terms of the combination of the symbols. However, since the winning symbol  34  of the sub reel  25  is displayed through the blank symbols  31   b ,  31   d  and  31   e , the player wins in this game and gets the dividend coins, whose amount is determined based on the type of the win. 
   On the other hand, if the losing symbol  35  of the sub reel  25  is displayed when the sub reel  25  stops rotating as shown in  FIG. 16 , the player loses in this game. If, as shown in  FIG. 17 , the re-rotation symbol  36  of the sub reel  25  is displayed when the sub reel  25  stops rotating, the CPU  90  determines the stop positions of the blank symbols  31   a ,  31   c  and  31   e  and the symbol  34  of the sub reel  25  again. Simultaneously, the CPU  90  rotates and stops the first to third displays  21 ,  22  and  23  through the motor controller  96 , in the same manner described above. Then, the CPU  90  rotates and stops the reel mounting plate  24  and the sub reel  25  in the order mentioned if the blank symbols of the first to third display parts  21   a ,  22   a  and  23   a  stop on the same winning line. After the sub reel  25  is stopped, the winning judging section  110  judges whether the win or the loss. 
   Since two different games in a single symbol display device are associated with each other, a player may continue to have expectation for the win in one game even after losing in the other game. Moreover, such symbol display device can provide sufficient appeal to a player by giving a variety of display types. 
   The first to third display plates  21 ,  22  and  23  may be rotated into the same direction, or one of them may be rotated in the opposite direction. It is also possible to change the rotational speed of each of the first to third display plates  21 ,  22  and  23 . The order to stop the rotation of the first to third display plates  21 ,  22  and  23  is not limited in the above embodiment. 
   If the two same symbols are arranged on one of the winning lines when two display plates stop rotating, the remaining display plate may rotate slowly or repeat the rotation in the clockwise and counterclockwise directions alternately such that the remaining display plate rotate clockwise little by little. Thereby, the symbol display device may provide a variety of performances to sustain the player&#39;s interest. The first to third display plates  21 ,  22  and  23  and the sub reel  25  may be stopped not only automatically but by the manual operation of the stop button. 
   Though lightings such as lamps and LEDs are not described in the above embodiment, it is possible to emit light in the front panel  11  during the rotation of the first to third display plates and the sub reel. It is also possible to change the color of emitted light when one of the first to third display panels rotates in the opposite direction as other display panels. 
   It is possible to move the reel mounting plate  24  to the initial position in which the rotary shaft of the sub reel  25  is overlapped with one of the standard line  88  in FIG.  3 . 
   The display device of the present invention may be composed of two or more than three display panels without losing the effects of the present invention. Note that the symbols other than the blank symbol may be transparent or non-transparent. The display plate is not necessarily transparent except the display part, but the area that overlaps the display part of other display plate may be partially opaque. In this case, the reel mounting plate is rotated to move the sub reel behind the blank symbol only if the blank symbols of the first to third display plates are arranged in line on the same winning line and, simultaneously, the blank symbol is overlapped with the transparent parts of the other display plates. After the reel mounting plate stop rotating, the sub reel is rotated. On the other hand, if the blank symbol is overlapped with the opaque parts of the other display plates, the reel mounting plate is not rotated. 
   Though the first to third display plates are formed of three rotary disks having the same diameters in the above embodiment, they may have different diameters. The present invention is not limited to the embodiment in which the first display part is the smallest while the third display part is the largest. For instance, the first display part may be the largest while the third display part may be the smallest. The second display part may be the largest among the three display parts. In addition, the first to third display plates may have other shapes, such as polygon. 
   Although reel mounting plate in the above embodiment is rotated only when the blank symbols on the first to third display parts are arranged in line, the reel mounting plate may be rotated together with the first to third display plates. In this case, the reel mounting plate may rotate in the same direction as the first to third display plates as well as in the opposite direction. In addition, the sub reel may rotate together with the reel mounting plate. The present invention is not limited to the embodiment in which the reel mounting plate is stopped when the sub reel reaches the position behind the blank symbol. For example, the sub reel may be rotated in the opposite direction to the position behind the blank symbol once after passing the blank symbol. 
   The blank symbol of the sub reel is displayed at the start of the game in the above embodiment. However, any symbols of the sub reel may be displayed initially. When the blank symbols of the first to third display parts stop on the same winning line, whether to rotate the reel mounting plate or the sub reel may be determined by lottery. It is not necessary to stop the sub reel at the position behind the blank symbols of the first to third display parts on the same winning line. 
   Instead of the sub reel, it is possible to use other display device, such as a liquid crystal display device or a display device of dot matrix style or 7 segments style, to display the symbols and the quasi-movement of the symbols. It is also possible to change the number and position of the sub reel. For example, plural sub reels may be mounted to the reel mounting plate at predetermined intervals or at random intervals. Plural sub reels having different symbols provide various winning types. 
   Although the sub reel is overlapped with the first to third display parts in the above embodiment, the sub reel may be overlapped with only one of the display parts.  FIG. 18  shows an example of the sub reel disposed behind the second display part. In this case, a reel mounting plate  143  begins the rotation after first to third display parts  140   a ,  141   a  and  142   a  stop rotating. When the sub reel  145  reaches the predetermined position behind a blank symbol  144   a  of a second display part  141   a , the sub reel  145  rotates to display symbols in motion and stops rotation. Accordingly, the player may expect the chance to win due to the rotation of the sub reel  145  even after losing the game in the main display means. 
   The display plate may be partially opaque in the area that overlaps the display part of other display plates. In that case, the reel mounting plate is rotated after the display plates are stopped. When the sub reel is stopped in an area where the blank symbol of one of the display plates is overlapped with the transparent areas of the other two display plates, the sub reel is rotated to display symbols in motion. 
   It is possible to provide a composite symbol of the symbol of the sub reel and the symbol in front of the sub reel. In the following explanation, the same elements as those in the above embodiment are represented by the same reference numerals. In  FIG. 19 , the star symbols  150 ,  151  and the number symbols “1” to “10” are provided in the second display part  152   a . The star symbols  150 ,  151  to represent the loss are disposed respectively in transparent parts  153  and  154 . When the star symbol  150  and the blank symbols  156 ,  157  of the first and third display parts  21   a ,  23   a  are arranged on one of the winning lines, the reel mounting plate  24  is rotated to move the sub reel  25  behind the blank symbols  156  and  157  and the star symbol  150 . The sub reel  25  behind the star symbol  150  starts rotating. 
   For instance, a symbol  160  of the sub reel  25  is displayed behind the star symbol  150 , as shown in FIG.  20 . In that case, the symbol  160  is overlapped with the star symbol  150  to form a composite symbol  161 , so that more dividend coins than other wins are dispensed. It is possible to change the number and the kinds of the composite symbols. In addition, though the star symbols  150  and  151  are provided in transparent parts  153  and  154  in the above embodiment, only the part inside the star symbols  150 ,  151  may be transparent and the parts outside the star symbols  150 ,  151  may be opaque. In that case, the symbol of the sub reel is observable through the transparent part inside one of the star symbols  150 ,  151 . 
   The star symbol  150  is not necessarily stopped on the same line as the blank symbols of the first and third display. It is possible to rotate the sub reel when the star symbol is arranged with other symbols (number symbol, for instance) than the blank symbol. Furthermore, it is also possible to provide three sub reels corresponding to the first to third display parts, and to judge the win or loss based on the symbols on three sub reels. 
   In the above embodiment, the reel mounting plate (rotator), to which a sub reel (sub display means) is mounted, is disposed behind and concentrically with the first to third. Instead, plural reel mounting plates may be provided. In the following explanation, the same elements as those in the above embodiment are represented by the same reference numerals. As shown in  FIG. 21 , the sub reel  25  is mounted on a transparent reel mounting plate  165 . Behind the reel mounting plate  165 , a sub reel  166  is mounted on a reel mounting plate  167 . The reel mounting plate  167  is attached to a rotary shaft  168  by a flange  169 . The reel mounting plates  165 ,  167  are concentric with each other. The reel mounting plates  165  and  167  are separately rotatable. Thus, the sub reels  25 ,  166  may be stopped at different positions to perform various display patterns. 
   Though the symbol display device is used to execute a sub game after the win in the main game (the slot game) in the above embodiment, the symbol display device of the present invention may be also applicable to a device to determine the amount of dividend coins in the main game or to execute the main game. 
   The symbol display device of the present invention may be mounted in the other game machine such as a Pachinko game machine. As shown in  FIG. 22 , a symbol display device  173  of the present invention is mounted behind a display window  172  formed in the center of a game board  171  in a Pachinko game machine  170 . The first to third display plates start rotating under a specific condition such as that, for example, a ball enters a particular hole among winning holes  174  on the game board  171 . The player wins a jackpot if the same symbols on the first third display plates are arranged in line. When the blank symbols on the first to third display plates stop in line, the reel mounting plate starts rotating to move the sub reel to behind the blank symbols. Then, the sub reel starts rotating and stops to display the symbol. The player wins a jackpot if the winning symbol of the sub reel is displayed. In the jackpot, an attacker  176  repeats opening and closing a predetermined times, and the player may win a number of premium balls if a boll enters the attacker  176  while it opens. Therefore, the symbol display device of the present invention may give sufficient appeal to the player to win the jackpot, and its various display patterns may enhance the interest of the game. 
   In the Pachinko game machine, whether the win or the loss is determined by the lottery when a specific condition is completed. In accordance with the result of the lottery, the stop positions for the first to third display plates and the sub reel of the symbol display device are determined. In response to the determination, the symbol display device is operated to rotate the first to third display plates. 
   In the above embodiments, the symbol display device judges whether the win or the loss in accordance with the combination of the symbols of the first to third display parts and the symbol of the sub reel after the rotation of the first to third display parts and the sub reel. Instead, the symbol display device may determine the win or the loss, and then determine the sop position of the first to third display plates and the sub reel. 
   Various changes and modifications are possible in the present invention and may be understood to be within the present invention.