Abstract:
A gaming machine artwork assembly includes a carrier on which images to be illuminated are carried. An electroluminescent illuminating arrangement is mounted on an operatively rear surface of the carrier. The electroluminescent illuminating arrangement comprises a plurality of electroluminescent elements, at least one element being associated with each image to be illuminated. A driver circuit is connected to the illuminating arrangement for driving the electroluminescent illuminating arrangement to illuminate selected electroluminescent elements of the arrangement on command from a controller of the gaming machine. The driver circuit includes individual drivers for each electroluminescent element for independently driving the electroluminescent elements and variably controlling the intensity of the illumination of the images with which said electroluminescent elements are associated.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 10/498,340 filed Dec. 2, 2004, which is a 371 of PCT/AU/03/00948 having an International filing date of Jul. 28, 2003, which claims priority to Australian Application No. 2002950569 filed Jul. 29, 2002, which is incorporated herein by reference in its entirety. 
     
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    [Not Applicable] 
       MICROFICHE/COPYRIGHT REFERENCE 
       [0003]    [Not Applicable] 
       BACKGROUND OF THE INVENTION 
       [0004]    This invention relates to a gaming machine. More particularly, the invention relates to a gaming machine artwork assembly and to a method of illuminating gaming machine artwork. 
         [0005]    Presently, to light artwork associated with a game of a gaming machine, it has been necessary to use incandescent lighting or light emitting diodes (LED&#39;s). Incandescent lights have a limited life span and, by using them, the game can lose its effectiveness by not having the artwork light up as required. 
         [0006]    The intensity of incandescent lights or LED&#39;s cannot easily be adjusted nor adjusted sufficiently rapidly to give a realistic impression of the events occurring in the game. As a result, when it is necessary to change lighting intensity or to light up a component or image of the artwork, in response to an event in the game, this cannot be easily achieved within the required time span. 
         [0007]    It will also be appreciated that the artwork comprises numerous images each of which may require separate illumination. To effect back lighting of these images by using incandescent lights or LED&#39;s, shielding in the form of metal or plastics formwork needs to be applied about each image to inhibit light leakage. The shielding has to be accurately mounted to match the artwork images. Any mismatch or out of tolerance mounting of the shielding causes overlapping with other images of the artwork or, in the case of finer&#39; images, lighting the wrong image altogether. The requirement to make use of shielding has also made it extremely difficult to light irregular, odd shapes or fine images. 
         [0008]    Australian Patent No 741427 (International Publication No WO 99/39552) in the name of Screen Sign Arts Limited entitled “Electroluminescent display” discloses the use of electroluminescent material for illumination purposes. The contents of Australian Patent No 741427 are specifically incorporated in this specification by reference. The applicant proposes use of an electroluminescent illuminating arrangement. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    According to a first aspect of the invention, there is provided a gaming machine artwork assembly which includes: 
         [0010]    a carrier on which images to be illuminated are carried; 
         [0011]    an electroluminescent illuminating arrangement mounted on an operatively rear surface of the carrier, the electroluminescent illuminating arrangement comprising a plurality of electroluminescent elements, at least one element being associated with each image to be illuminated; and 
         [0012]    a driver circuit connected to the illuminating arrangement for driving the electroluminescent illuminating arrangement to illuminate selected electroluminescent elements of the arrangement on command from a controller of the gaming machine, the driver circuit including individual drivers for each electroluminescent element for independently driving the electroluminescent elements and variably controlling the intensity of the illumination of the images with which said electroluminescent elements are associated. 
         [0013]    The carrier may be a planar sheet of material on which the images are carried. The sheet may be a sheet of plastics material. 
         [0014]    Each element of the electroluminescent illuminating arrangement may comprise, as described in Australian Patent No 741427, a pair of electrodes sandwiching a dielectric layer and a phosphor layer, a first, operatively front electrode being mounted to the rear surface of the carrier. The front electrode may be of a transparent material and, conveniently, may be in the form of an indium tin oxide layer. The phosphor layer may be carried on a rear surface of the front electrode and is at least partially encapsulated by the dielectric layer. A second, rear electrode may be arranged on top of the dielectric layer to form a structure having a capacitive impedance. 
         [0015]    When an alternating voltage is applied across the electrodes, a time-varying electric field is generated in the phosphor layer and the dielectric layer. Electroluminescence occurs in the element by exciting atoms of the phosphor layer by means of the electric field. When the excitation of the atoms is removed, decay to a ground state of the atoms occurs via the emission of radiant energy in the visible spectrum resulting in illumination by the electroluminescent element. 
         [0016]    As indicated above, the driver circuit may include a driver associated with each electroluminescent element. 
         [0017]    The driver circuit may include a control device. The control device may be a dedicated microprocessor executing proprietary software for individually controlling each driver. The driver associated with each electroluminescent element of the artwork may be mapped to a memory location of the microprocessor and may be illuminated on command from the controller of the gaming machine. 
         [0018]    The microprocessor may employ a modulation technique for controlling the intensity of illumination of each electroluminescent element. The modulation technique employed may be a pulse width modulation (PWM) technique. 
         [0019]    The electroluminescent element may be driven by means of an AC signal. Typically, the AC signal has a frequency of about 500 to 1,000 Hz, preferably, about 600 to 900 Hz and, optimally, about 800 Hz. 
         [0020]    Each driver may include a zero voltage detector circuit which detects a zero crossing of each cycle of the AC signal. For lower intensity, the AC signal may be turned off on the zero crossing for a predetermined number of cycles to obtain the required intensity of illumination. It will be appreciated that, due to the frequency of the AC signal, even if the signal is turned off for a number of cycles, it will be undetectable by the human eye and the likelihood of observing flicker is small. 
         [0021]    For maximum intensity, the signal may not be turned off for any number of cycles. For zero illumination, the signal remains off and, for an intermediate intensity, the signal may be turned off for the appropriate number of cycles. 
         [0022]    Assuming eight levels of illumination from zero intensity to maximum intensity, seven cycles of the AC signal are used, zero intensity having no signal. The number of levels could be increased or decreased depending on the number of cycles used. The electroluminescent elements are capacitive in nature, resulting in the AC current signal leading the AC voltage signal by 90°. Therefore, the zero voltage detector may detect a zero crossing of the voltage signal and, from that, determine or calculate a maximum or peak voltage of the AC voltage signal to determine the zero crossing of the associated AC current signal. In the case of half intensity, the driver circuit may, therefore, turn on at a maximum voltage of a first cycle of the AC voltage signal, turn off at a maximum voltage of the fourth cycle and, to commence the next period of illumination, turn on again at a maximum voltage of the eighth cycle. 
         [0023]    The artwork may be arranged in a top box and/or on a belly board of the gaming machine. Additionally, artwork, in accordance with the invention, may be included in tower-like components, known as “traffic lights”, on one or both sides of a monitor of the gaming machine. The “traffic lights” may be mounted on a door of the gaming machine. Due to the light weight of the artwork of the invention, no major structural alterations to the door are required. 
         [0024]    According to a second aspect of the invention, there is provided a method of illuminating gaming machine artwork, the method including the steps of: 
         [0025]    providing a carrier on which images to be illuminated are carried; 
         [0026]    illuminating selected images on the carrier on command from a controller of the gaming machine by means of electroluminescent elements of an electroluminescent illuminating arrangement mounted on an operatively rear surface of the carrier; and 
         [0027]    controlling the intensity of illumination of the electroluminescent elements to control the intensity of illumination of the images. 
         [0028]    Each electroluminescent element may have a driver associated with it and the method may include driving each electroluminescent element independently via its driver to control the intensity of illumination of the image associated with that element independently of each other image. 
         [0029]    The driver associated with each electroluminescent element of the artwork may include a microprocessor and the method may include mapping to a. memory location of the microprocessor the driver associated with each electroluminescent element of the artwork and illuminating the electroluminescent element of each selected image on command from the controller of the gaming machine. 
         [0030]    The method may include using a modulation technique for controlling the intensity of illumination of each electroluminescent element. 
         [0031]    Further, the method may include driving each electroluminescent element by means of an AC signal. 
         [0032]    The method may include detecting a zero crossing of each cycle of the AC signal. For lower intensity illumination, the method may include turning off the AC signal on the zero crossing for a predetermined number of cycles to obtain the required intensity of illumination. 
         [0033]    The method may include detecting a zero crossing of an AC voltage signal and, from that, determining a peak voltage of the AC voltage signal to determine the zero crossing of an associated AC current signal. 
         [0034]    According to yet a further aspect of the invention, there is provided a gaming machine which includes 
         [0035]    a carrier carrying artwork associated with a game of the gaming machine; and 
         [0036]    an electroluminescent illuminating arrangement arranged behind the carrier for illuminating images of the artwork on command from a controller of the gaming machine. 
     
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         [0037]    The invention is now described, by way of example, with reference to the accompanying diagrammatic drawings in which: 
           [0038]      FIG. 1  shows a three dimensional view of a gaming machine, in accordance with an embodiment of the invention; 
           [0039]      FIG. 2  shows a block diagram of a control circuit of the gaming machine; 
           [0040]      FIG. 3  shows a schematic, sectional view of a part of artwork of the gaming machine; 
           [0041]      FIG. 4  shows a block diagram of control circuitry of the artwork; 
           [0042]      FIG. 5  shows a block diagram of a driver circuit of the control circuitry; 
           [0043]      FIG. 6  shows examples of waveforms of signals in the circuit of  FIG. 5 ; and 
           [0044]      FIG. 7  shows a front view of an example of gaming machine artwork, in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0045]    In  FIG. 1 , reference numeral  10  generally designates a gaming machine in accordance with an embodiment of the invention. The machine  10  includes a console  12  having a video display unit  14  on which a game  16  is played, in use. The game  16  may, for example, be a spinning reel game which simulates the rotation of a number of spinning reels  18 . A midtrim  20  of the machine  10  houses a bank  22  of buttons for enabling a player to play the game  16 . The midtrim  20  also houses a credit input mechanism  24  including a coin input chute  24 . 1  and a bill collector  24 . 2 . 
         [0046]    The machine  10  includes a top. box  26  on which artwork  28 , in accordance with an embodiment of the invention, is carried. The artwork  28  includes images related to the game  18 . Further artwork  42 , which, desirably, is also in accordance with an embodiment of the invention, is carried on a belly board  44  of the gaming machine  10 . 
         [0047]    A coin tray  30  is mounted beneath the console  12  for cash payouts from the machine  10 . 
         [0048]    Referring now to  FIG. 2  of the drawings, a control means or control circuit  32  is illustrated. A program which implements the game and user interface is run on a processor  34  of the control circuit  32 . The processor  34  forms part of a controller  36  that drives the screen of the video display unit  14  and that receives input signals from sensors  38 . The sensors  38  include sensors associated with the bank  22  of buttons and touch sensors mounted in the screen of the video display unit  14 . The controller  36  also receives input pulses from the mechanism  24  to determine whether or not a player has provided sufficient credit to commence playing. The mechanism  24  may, instead of the coin input chute  24 . 1  or the bill collector  24 . 2 , or in addition thereto, be a credit card reader (not shown) or any other type of validation device. 
         [0049]    Still further, the controller  36  controls illumination of the artwork  28  and  42 , as will be described in greater detail below. 
         [0050]    Finally, the controller  36  drives a payout mechanism  40  which, for example, may be a coin hopper for feeding coins to the coin tray  30  to make a pay out to a player when the player wishes to redeem his or her credit. 
         [0051]    Referring to  FIG. 4  of the drawings, the artwork  28 ,  42  is described in greater detail. The artwork is represented schematically at  50  in  FIG. 4  of the drawings. As shown in  FIG. 3  of the drawings, the artwork  50  comprises a front carrier or panel  52  which is transparent. An electroluminescent illuminating arrangement  54  is arranged on an operatively rear surface of the panel  52 . It is to be noted that the panel  52  carries images such as those shown in  FIG. 7  of the drawings. 
         [0052]    The electroluminescent illuminating arrangement  54  comprises a plurality of electroluminescent illuminating elements  56 . Each image on the panel  52  has one or more elements  56  associated with it. 
         [0053]    The electroluminescent illuminating arrangement  54  comprises a first, operatively front, transparent electrode  58 . The electrode  58  covers the rear surface of the carrier  52  and is an indium tin oxide layer. 
         [0054]    Each electroluminescent element  56  comprises, in addition, a phosphor layer  60  in the shape of the image to be illuminated. The layer  60  is applied to an operatively rear surface of the first electrode  58 . The phosphor layer  60  is encapsulated in a dielectric layer  62 . It is to be noted that the dielectric layer  62  overlies the phosphor layer  60  of each of the various elements  56  of the electroluminescent illuminating arrangement  54 . 
         [0055]    Finally, a second, operatively rear electrode  64  which, once again, is in the shape of the image on the panel  52  to be illuminated is applied to the dielectric layer  62  in register with its associated phosphor layer  60 . The electrode  64  is of any suitable conductive material, for example, silver. 
         [0056]    It will be appreciated that the electrodes  58  and  64 , together with the dielectric layer  62  and phosphor layer  60  sandwiched between them, form a structure having a capacitive impedance. When an alternating electric field is applied to the electrodes  58  and  64 , phosphorescence of the layer  60  occurs. This occurs as a result of, once the electric field has been removed, atoms in the layer  60  returning to their ground state by releasing energy which is in the visible spectrum of light. 
         [0057]    It is also to be noted that the connection to each of the electrodes  58  and  64  have been omitted from  FIG. 3  for the sake of clarity. Reference is made to Australian Patent No. 741427 where the connections are described in greater detail. 
         [0058]    The artwork  50  is driven by one or more driver circuits  66  ( FIG. 4 ). Each driver circuit  66 , in turn, is controlled by a controller board  68 . The controller board  68  receives commands from the game controller  36  via a sequencer  70 . The controller board  68  receives electrical power from a high voltage power supply  72  which provides an AC signal having a frequency in the range of about 500 to 1000 Hz, preferably about 600 to 900 Hz and, optimally, about 800 Hz to the driver circuits  66 . 
         [0059]    The artwork  28 ,  42  also includes a plurality of light emitting diodes (LED&#39;s) arranged about a periphery of the artwork  28 ,  42 . These LED&#39;s are commonly referred to as chaser LED&#39;s  74  which are driven by an LED driver  76  from the controller board  68 . It is to be noted in  FIG. 7  of the drawings that part of the image in the top box  26  of the artwork  28  is a screen  78 . The screen  78  is an LED screen and displays jackpot amounts for a mini, minor, major and grand jackpot associated with the applicant&#39;s game  18 , Jackpot Deluxe™. The LED&#39;s of the screen  78  are also driven by the controller board  68 . 
         [0060]    A further lighting arrangement can be mounted on the gaming machine  10  on each side of the video display unit  14 . Although not shown in  FIG. 1  of the drawings, a column of electroluminescent devices, commonly referred to as “traffic lights”  79  ( FIG. 4 ), may be mounted on opposed sides of the video display unit  14 . The “traffic lights”  79 , being of electroluminescent construction, are relatively lightweight. As a result, the “traffic lights”  79  can be mounted on a door of the gaming machine without significant, if any, structural modification to the door being required. The “traffic lights”  79  are controlled by the controller board  68 . 
         [0061]    Referring now to  FIG. 5  of the drawings, a block diagram of part of the circuitry of the artwork, including the driver circuit  66 , is shown. 
         [0062]    The driver circuit  66  includes a driver  80  for each electroluminescent element  56 . Each driver  80  is controlled by a control device, in the form of a microprocessor  82 , which, in turn, is controlled by the controller  36  of the gaming machine  10 . The drivers  80  constitute an interface between low and high voltage circuitry of the artwork  50 . 
         [0063]    The microprocessor  82  is a dedicated unit executing proprietary software. Individual electroluminescent elements  56  of the electroluminescent illuminating arrangement  54  are mapped to memory locations of the microprocessor  82 . The appropriate image of the artwork  50  is illuminated by energising the relevant electroluminescent element or elements  56  associated with that image with the required intensity of illumination as determined by the microprocessor  82  under the control of the controller  36 . 
         [0064]    Each electroluminescent element  56  is supplied with an AC signal. As indicated above, the AC signal has a frequency of, optimally, approximately 800 Hz. 
         [0065]    To effect the required intensity of illumination of the relevant image, the AC signal is modulated by a pulse width modulation (PWM) technique. 
         [0066]    The PWM technique employed relies on a zero crossing of cycles of an AC current signal. For this purpose, the driver circuit  66  includes a zero voltage detector  84 . An AC voltage signal is supplied from the AC power supply  72  to the driver circuit  66  on a line  86 . The AC voltage signal fed to the driver circuit  66  on line  86  is shown at  88  in  FIG. 6  of the drawings. 
         [0067]    The zero voltage detector  84  detects the zero crossing of the AC voltage signal  88 . From that, the detector  84  determines the position of the peak of each voltage cycle of the signal  88  using the frequency of the signal  88 . Because the electroluminescent elements  56  are capacitive in nature, a current signal, an example of which is shown at  90  in  FIG. 6  of the drawings, supplied to the artwork  50 , leads the voltage signal  88  by 90°. Having determined the position of the peak voltage of each cycle of the signal  88 , the zero voltage detector  84  is able to determine the zero crossing position of each cycle of the AC current signal  90  as it is in phase with the peak voltage of each cycle of the signal  88 . 
         [0068]    The processor  82  of the driver circuit  66  issues a control signal  91  as shown in  FIG. 6  of the drawings under the control of the controller board  68  or sequencer  70 , as the case may be. The signal  91  is input to a gate of a triac (not shown) of the relevant driver  80  of the driver circuit  66  which connects the electroluminescent element  56  associated with that driver  80  to ground causing the current signal  90  to be supplied by the driver  80  to the relevant electroluminescent element  56  of the artwork  50 . 
         [0069]    It is assumed that, for full intensity illumination, seven cycles of the signal  88  are required. The example shown in  FIG. 6  of the drawings illustrates the example of an electroluminescent element  56  being illuminated at 50% intensity of illumination. The current signal  90  is output by the driver  80  to its associated electroluminescent element  56  of the artwork  50 . Thus, at the input to the driver  80 , the signal  91  goes high on at a maximum voltage of a first cycle  92  of the signal  88  as shown in  FIG. 6  of the drawings. The signal  91  goes low at the maximum voltage of the fourth cycle  94  of the signal  88  and, to commence the next period of illumination, again goes high at the maximum voltage of the eighth cycle  96  of the signal  88  to provide a 50% illumination of the artwork  50 . As indicated above, while the signal  91  is high, the current signal  90  is applied to the electroluminescent element  56  being controlled. 
         [0070]    For various other intensities of illumination, the signal  91  goes low for longer or shorter periods of time, as the case may be. It will be appreciated that, due to the relatively high frequency of the current signal  90 , observable flicker will be minimised. As each element  56  is separately controlled, it will also be appreciated that each image of the artwork  50  can be illuminated with light of the desired intensity independently of any other image of the artwork  50 . 
         [0071]    It is to be noted that, to spread the load over different cycles of the power supply  72 , different electroluminescent elements  56  are turned on and off at different cycles of the AC signal  88 . 
         [0072]    Referring to the specific example shown in  FIG. 7  of the drawings, it is to be noted that various images are displayed. Each of these images is individually illuminated by its own electroluminescent element or elements  56 . Thus, for example, a star image as illustrated at  98  is illuminated by its own electroluminescent element  56 . A champagne bottle  100 , which may or may not be illuminated, may give the effect of champagne spouting from the bottle  100  in a region  102  of the artwork  28 , the region  102  being illuminated by one or more electroluminescent elements  56 . 
         [0073]    Still further, a champagne flute  104 , or parts thereof, is/are individually illuminated as are various other icons such as those indicated at  106  associated with jackpot prizes of the applicant&#39;s game Jackpot Deluxe™. 
         [0074]    It is a particular advantage of the invention that individual elements  56  can be illuminated by means of the electroluminescent illuminating arrangement  54 . The artwork  50  can comprise any number of images to be illuminated. For example, for the artwork  28  shown in  FIG. 7  of the drawings,  192  individual images to be illuminated are included in the artwork  28 . Each image can be illuminated separately and individually with its own intensity under the control of the microprocessor  82  and the controller  36  of the gaming machine  10  in response to particular actions in the game  16  on the gaming machine  10 . 
         [0075]    Due to the fact that each electroluminescent element  56  is constituted by layers, very fine detail can be formed in the images such as the stars  98  shown in the artwork  28  in  FIG. 7  of the drawings without leakage of light or the need for metal or plastics formwork. 
         [0076]    The benefit of switching the signal  88  at a zero crossing also results in reduced emissions and makes the design more robust. 
         [0077]    The electroluminescent illuminating arrangement  54  is rapidly switchable so that the artwork  28  can be illuminated in real time relative to the events in the game  16 . 
         [0078]    It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.