Field of the Invention

The present invention relates to jackpot awarding systems, controllers and methods of gaming. It particularly relates to techniques for implementing mystery jackpots for table games such as Baccarat, Roulette, Sic Bo, Money Wheel, Craps and other casino table games with a communal result.

Background of the Invention

Having a progressive jackpot associated with a casino table game is now widespread and features in most casinos worldwide. Typically, a physical bet sensing device is used to detect side bets made by players, said side bets contributing to an incrementing jackpot fund and confirming a player’s eligibility to win the jackpot.

Typically, the progressive jackpot is triggered by either a specific predefined game outcome or by random means. The possibility of winning a jackpot draws more players to the casino game and encourages the players to play for longer as they hope to win the jackpot prize.

Jones, et al. (U.S. Pat. No. 5,078,405) discloses a method and apparatus for including a progressive jackpot component in a live casino table game. In addition to playing a live casino table game, each player makes an additional wager at the beginning of each hand that makes that player eligible to win all or part of a jackpot. If during the play of the hand, a player is dealt a predetermined arrangement of cards, the player wins a preselected percentage of the jackpot amount.

A mystery jackpot is a type of jackpot typically linked to electronic gaming machines. The jackpot increases in value as a function of each wager made until it is won.

Once won, the jackpot is initialised to a starting value and the process begins again. A mystery progressive jackpot is defined by a starting and ending (maximum) value. The award must be won before the jackpot value grows larger than the maximum value. Mystery jackpots are triggered by random means. Wity, et al (U.S. Pat. No 9336643) discloses a computer-implemented method of playing an auxiliary mystery progressive jackpot game during play of an associated live casino base game, which is comprised of wager registration devices, random means for triggering a mystery jackpot and indicators displaying a sequence indicating the winning side wager beting position.

The methods and apparatus employed by mystery jackpot systems typically differ between electronic gaming machine systems and table game systems. In the case of electronic gaming machines, mystery jackpots are funded by taking a percentage of the player’s bet for each game and adding it to the jackpot pool. This is achieved as bets are made using electronic devices and processing jackpot contributions and wins are automated.

In the case of table game jackpots, typically registration means are employed to detect a side bet consisting of a single beting chip. Reliability limitations of the current technology typically require a single beting chip to be placed on a sensing device to register the bet to contribute to the mystery jackpot.

Technologies utilizing RFID and camera technology exist to detect players' bets on table games but these technologies are expensive and may not be accurate enough to be used to detect all qualifying bets placed on a busy table game. Consider a game like Roulete or Baccarat where multiple players can place a large number of bets, typically comprised of stacks of beting chips sometimes up to 20 units in height, on a communal playing surface.

Summary of the Invention

In accordance with a first aspect there is provided a system for awarding a mystery jackpot prize for a table-based wager game, the system comprising: at least one table on which the wager game is playable, each table comprising: an event determination means for determining when a predefined game event has occurred; a table controller electrically communicable with the event determination means and configured to output a signal when the event determination means has determined one of the predefined game events, the signal comprising a unique identifier for the corresponding table; a jackpot controller comprising: a communications module for receiving the signals output from the table controllers; a random number generator; and an account module configured to maintain: a table register associating the unique identifier for each participating table with a prize pool increment value; a mystery jackpot prize pool having a minimum start value and a maximum trigger value; and wherein in response to receiving a signal output from one of the table controllers, the account module is configured to evaluate the table register and increase the jackpot prize pool by the increment value for the associated table and such that when the value of the mystery jackpot prize pool reaches a randomly determined trigger value between the minimum and maximum values the account module is configured to award the mystery jackpot prize to the table that made the associated increment, the mystery jackpot prize being funded from the mystery jackpot prize pool.

In accordance with a second aspect there is provided a system for awarding a mystery jackpot prize for a virtual table-based wager game, the system comprising: at least one electronic gaming terminal for receiving a wager on the game; a central controller for facilitating play of the game, the central controller comprising: a communications module for receiving the player wagers; a random number generator; and an account module configured to maintain: a register associating at least one table on which the game is played with a prize pool increment value; a mystery jackpot prize pool having a minimum start value and a maximum trigger value; and wherein, for each of the at least one tables, in response to a predefined event occurring during play of the game thereon, the account module is configured to evaluate the register and increase the jackpot prize pool by the increment value for the associated table and such that when the value of the mystery jackpot prize pool reaches a randomly determined trigger value between the minimum and maximum values the account module is configured to award the mystery jackpot prize to the table that made the associated increment, the mystery jackpot prize being funded from the mystery jackpot prize pool.

In accordance with a third aspect there is provided a system for awarding a mystery jackpot prize for a wager game, the system comprising: at least one electronic gaming terminal operable by a player for receiving a wager on the game; a central controller for facilitating play of the game, the central controller comprising: a communications module for receiving the player wagers; a random number generator; and an account module configured to maintain: a mystery jackpot prize pool having a minimum start value and a maximum trigger value; and wherein, in response to a predefined event occurring during play of the game, the account module is configured increase the jackpot prize pool by a predefined increment value for and such that when the value of the jackpot reaches a randomly determined trigger value between the minimum and maximum values the account module is configured to award the mystery jackpot prize to players that placed qualifying wagers on the game, the mystery jackpot prize being funded from the mystery jackpot prize pool.

In accordance with a fourth aspect there is provided a system for awarding a mystery jackpot prize for a table-based wager game, the system comprising: at least one dealer station for implementing play of the wager game, each dealer station comprising: an event determination means for determining when a predefined game event has occurred; a station controller electrically communicable with the event determination means and configured to output a signal when the event determination means has determined one of the predefined game events, the signal comprising a unique identifier for the corresponding station; a jackpot controller comprising: a communications module for receiving the signals output from the station controller(s); a random number generator; and an account module configured to maintain: a register associating the unique identifier for each participating dealer station with a prize pool increment value; a mystery jackpot prize pool having a minimum start value and a maximum trigger value; and wherein in response to receiving a signal output from one of the controllers, the account module is configured evaluate the register and increase the jackpot prize pool by the increment value for the associated station and such that when the value of the mystery jackpot prize pool reaches a randomly determined trigger value between the minimum and maximum values the account module is configured to award the mystery jackpot prize to players that placed qualifying wagers with the dealer station that triggered the jackpot prize, the mystery jackpot prize being funded from the mystery jackpot prize pool.

In accordance with yet another aspect there is provided a computer readable medium comprising computer program including at least one instruction which is arranged to implement the method as described in accordance with any of the preceding aspects.

An embodiment of the apparatus further includes a central controller for running a gaming algorithm, and a plurality of remote clients in communication with the central control over a communications network, the remote clients including screens for the display of information to players.

Embodiments of the present invention may be applied in non-table based format on any suitable type of gaming system or platform. For example, they can be implemented by a stand-alone gaming apparatus, e.g. electronic gaming machines, such as video gaming machines, to gaming machines that are linked together, e.g. via a network such as an intranet, and/or to gaming systems provided through computing or other electronic devices, e.g. personal computers, PDAs, mobile telephones, digital televisions, and the like, e.g. over the Internet or other communications networks.

Brief Description of the Drawings

Features and advantages of the present invention will become apparent from the following description of embodiments thereof, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic block diagram of a gaming system, according to an embodiment of the present invention;

Figure 2 is a plan view of a casino gaming table showing an example wager game for which an embodiment of the present invention is applicable;

Figure 3 is a schematic block diagram of operative components of a jackpot controller of the gaming system, according to an embodiment; and

Figure 4 is a flowchart of an embodiment.

Detailed Description

Embodiments described herein relate to a jackpot awarding system for table-based wager games whereby all players who place a qualifying bet on a wager outcome are eligible to win a mystery jackpot. The system as described herein allows contributions to be made to the mystery jackpot on a per-game round basis using means that allow for a predetermined game state (e.g., the outcome of a game or the no more betting state of a game) to be communicated to a central jackpot controller responsible for awarding the mystery jackpot. Such means may include, for example, sensors in roulette wheels, devices that read the indicia on playing cards, or manual input means where dealing staff confirm game timing events. When a mystery jackpot is triggered, all players who placed a qualifying bet on the standard game wager share in the jackpot. As will be described in more detail in subsequent paragraphs, a qualifying wager can be any wager offered by the game or a specific wager such as a tie bet or a pairs bet for the game of Baccarat. It will be understood that embodiments may be implemented either in physical form (i.e., where wagers are placed on a physical wager table operated by a croupier), or in a virtual form (e.g., played in an automated fashion on an electronic gaming terminal, or on a personal computer or mobile device via the internet, or the like).

An embodiment of the present invention that is particularly suited for playing in a casino is shown in Figure 1. According to the illustrated embodiment the game takes the form of Baccarat played on a physical table 12. It will be understood, however, that embodiments are not so limited and that embodiments may extend to other table games, such as Roulette, Sic Bo, Money Wheel, Craps and other casino table games with a communal result.

With reference to Figure 1, the system 10 includes at least one physical table 12 on which a Baccarat wager game is playable. Each table 12 implements a table controller 16 which is communicable with a central jackpot controller 20, as will be described in more detail in subsequent paragraphs.

In essence, and with additional reference to Figure 2, Baccarat is a card comparing game played between two hands: the "Player" and the “Banker". Accordingly, for each player position (typically 7 to 14 player positions are included), each table 12 includes the following wager spaces: space 104 is marked "Player" for placing wagers on the player’s card total; space 106 is marked "Banker" for placing wagers on the banker’s card total; and space 108 is marked "Tie" for placing a wager that the point count of the banker's hand and the player's hand will be equal. Baccarat is played with four to eight decks of cards stored in a card shoe 14. Each deck consists of 52 cards without jokers.

Importantly, and as will be explained in more detail in subsequent paragraphs, the mystery jackpot is not funded from players’ bets. Rather, a fixed pre-determined contribution is used to increment the mystery jackpot, typically funded by the casino, thereby making all players who placed a qualifying bet eligible to win the jackpot (as opposed to only players who placed a dedicated jackpot bet as required for conventional table-based jackpot games). Thus, the table 12 does not require any wager sensing or bet registration means for implementing the jackpot. Returning to Figure 1, each of the participating gaming tables 12 is provided with an event determination means/apparatus 18 that is triggered (either manually or automatically) in response to one of the following game play states occurring which includes but is not limited to: a. Start of a new game b. Start betting phase c. No-more -bets phase of the game d. Game result e. Conclusion of the game

The event determination means 18 may, for example, comprise a sensor incorporated into the shoe 14 configured to sense the start of a new game when the first card of the game is drawn. In an alternative embodiment, the shoe 14 or table 12 may incorporate a button or other suitable input device (e.g., touchscreen, keypad, footswitch etc.) that a croupier can control to indicate one of the afore-described conditions. For example, the shoe 14 may include a “confirm result” button that the croupier presses to signal the game result. As another example, the event determination means may comprise a camera system with recognition software configured to recognise game states. As another example RFID tags and readers can be used to detect the location of playing cards and / or gaming chips to recognise/determine game states. As another example, motion sensors can be embedded in the table to detect a croupier’s hand gesture to indicate the game states.

The event determination means 18 is wired or wirelessly communicable with, or alternatively electrically integrated within, a table controller 16 implementing a communication circuit for communicating with the central jackpot controller 20 over a network 22, e.g., via Local Area Network. When a predefined game state is determined by the event determination means 18 it sends an electrical signal to the table controller 16 which in turn is configured to communicate a signal representative of that state to the central jackpot controller 20. The signal sent to the central jackpot controller 20 includes (e.g., encodes) a unique identifier for the associated table 12.

It will be understood that the communication signals sent by the respective communication table controllers 16 could take any suitable electronic form, depending only on the desired implementation. According to the presently described embodiment, the central jackpot controller 20 is responsible for implementing a mystery jackpot for wager games played on the gaming tables 12 (although it will be understood that the jackpot controller 20 could be incorporated into other network elements, such as a player tracking system etc., depending on the desired implementation).

With additional reference Figure 3, the jackpot controller 20 implements various modules for carrying out the above functionality.

In more detail, the jackpot controller 20 includes a processor 250 which is arranged to carry out a number of functions associated with maintaining a prize pool and awarding of jackpot prizes therefrom. It will be apparent that the processor 250 implements several modules, namely a prize trigger module 252, account module 254, communications module 256 and display controller module 258 based on program code stored in memory 260. For simplicity, only those modules (which may be implemented in software, hardware or a combination of the two) needed to carry out embodiments of the invention are illustrated.

The account module 254 is configured to initiate and maintain a mystery prize pool and award (or revoke if required) a jackpot prize therefrom. New mystery prize pools are initiated with a minimum start and maximum end (trigger) value. Once initiated, the account module 254 is configured to process communications received from the table controllers 16 for incrementing the mystery prize pool on a per game round basis. In this regard, the account module 254 is configured to maintain a table register (stored in memory 260) which stores a unique identifier for each participating table in association with a prize pool increment value. In response to receiving a state update signal output from a table controller 16, the account module 254 is configured to evaluate the entry in the table register forthat table (i.e., determined using the unique identifier encoded in the signal) and increase the value of the prize pool by the associated increment value. In one embodiment, the increment value stored in the table register for each table is a value associated with (i.e., a function of) the minimum or maximum bet for the table. It will be understood that the entry in the table register may change if the minimum or maximum bet value for a table increases or decreases. Further, according to a particular embodiment, the predefined table contributions may differ from one table grouping to another table grouping, such groupings being defined by parameters such as game type, table location, table minimum bet, table maximum bet, or any other group parameter determined by the casino operator. Irrespective of the size of the contributions, the prize pool increases in response to state update signals until it randomly triggers between the minimum and maximum value. According to the illustrated embodiment, this random trigger value is determined utilising a random number generator implemented by the trigger module 252. The table that made the triggering contribution is determined to be the “winning table”. In one embodiment the random trigger value is determined each time a state update signal is received from one of the table controllers 16. In an alternative embodiment, the random trigger value is determined at the time the prize pool is initiated.

Once the winning table has been determined, the jackpot goes in to a “pending” status until a determination has been made as to whether at least one player at the table made a qualifying bet during the triggering round. A positive determination (hereafter “confirmed jackpot”) results in the confirmation and awarding of the jackpot prize, whereas a negative determination (hereafter “unqualified jackpot”) results in the jackpot prize being revoked.

In one embodiment, a croupier at the winning table indicates to the jackpot controller 20 whether a qualifying bet was made. For example, a handset operated by the croupier may be operated to cause the table controller 16 to send a signal to the jackpot controller 20 that indicates whether a qualifying bet was made. In another embodiment, an automated detection means may determine that a qualifying bet has been made (e.g., using an image recognition system that is configured to recognise placement of a wager and which is communicable with the table controller 16 for instructing the communication signal to be sent). In yet another alternative embodiment, the confirmation signal may be encoded in the state update signal as described above. For example, where the predefined state is the “no more bets” stage of the game, the croupier may have the option of selecting one of two buttons on the handset where one button indicates to the table controller 16 that the predefined state has occurred and no wagers were placed, and the other that indicates to the table controller 16 that the predefined state has occurred, and qualifying wagers were placed. Irrespective of how or when the jackpot controller 20 makes the qualifying bet determination, triggering of a jackpot immediately causes a new jackpot to be initiated by the account module 254 with all subsequent contributions accrued as afore-described.

When a mystery jackpot has been confirmed, all players at the winning table who placed a qualifying wager on the base game will share in the jackpot. The jackpot may be divided by the winning players in one of several ways. In one embodiment the jackpot is evenly divided amongst the players. In another embodiment of the invention the jackpot is divided pro rata amongst the players according to the players’ bet wagers. In another embodiment certain bets have a higher weighting, as an example bets on Tie may be worth 5 times the value of bets placed on Player or Banker when dividing up the jackpot win.

Returning to Figure 1, an electronic display 200 located at each gaming table 12 is communicatively linked to the jackpot controller 20 and displays an odometer value which either shows the current jackpot prize pool value or an approximation of the prize pool value, typically a lower amount which is incrementing towards the actual amount. The display 200 may also provide an indication when that table has made a contribution to the mystery jackpot. When the mystery jackpot is triggered, the display 200 on the winning table indicates that it was the table which made the winning contribution and the winning prize amount. The display 200 may also display a winning animation sequence associated with the win. An animation sequence may also be displayed on the displays for tables that did not win the jackpot. A central display 300 may also be provided that displays some or all of the information afore described.

An unqualified jackpot (i.e., where no qualifying bets were made for the triggering round of play) results in the jackpot prize being revoked. The account module 254 may either re-direct some or all of the winning amount (minus the minimum start value) to the newly initiated jackpot prize pool, or alternatively re-claim the prize altogether. While pending, the table display 200 for the winning table may indicate that the jackpot is in a pending status.

To avoid the scenario where a jackpot is triggered at a value that is near the jackpot maximum and during the pending phase contributions to the new prize pool in addition to a reversed jackpot prize amount would push the new jackpot pool above a predefined value (that is lower than the jackpot maximum), then any jackpot amount exceeding the predefined value may be removed.

In the event of a jackpot win being subsequently revoked, and during the pending status prior to revocation, at which time the jackpot has initiated a new cycle, then if another win is triggered, the winning funds minus the start value from the preceding revoked jackpot are added to the winning amount of the current triggered jackpot, each jackpot win being processed in order of occurrence. If the first winning amount (minus the start value) added to the second winning amount would increment the jackpot above its predefined maximum, the amount above the maximum is removed (and optionally placed into a secondary jackpot pool, or alternatively added to the current jackpot pool). In this case the second winning amount is the predefined maximum.

Figure 4 depicts a general process flow for implementing an embodiment of the invention. At step SI, a new mystery prize pool is initiated. At step S2, the controller 20 receives an event signal from one of the participating gaming tables 12 and increments the prize pool accordingly. At step S3, the controller 20 determines if the event signal caused the mystery jackpot to trigger. If a positive determination was made, the controller 20 initiates a pending phase and initiates a new jackpot prize pool (i.e., returns to step SI). At step S4 the controller determines if a qualifying wager was made at the triggering table 12. If a positive determination was made the jackpot prize is awarded to players at the winning table that made qualifying wagers (S5). If a negative determination was made at step S4 then the jackpot prize is revoked (step S6) and the newly initiate prize pool adjusted accordingly (if necessary, per the desired embodiment).

In another embodiment electronic gaming terminals are provided for players to play table games such as Baccarat. Typically, there are dealer stations comprising playing cards, a card shoe and a game layout, replacing the traditional table, which are communicatively linked to each of the electronic terminals and the game is operated by a croupier at the dealer station with a video connection to large display screens, and to each terminal, so players can observe and participate in the game. Bets are made via a user interface and input device at the terminals. The same method is employed with electronic terminals whereby, at a predetermined game phase, a fixed contribution is made to a mystery progressive jackpot. All payers who made qualifying bets, for the round of play which triggered the jackpot, share the jackpot prize. The proportion of the jackpot prize is automatically calculated as the electronic terminal gaming system records data for each of the players bets which can be used to determine the prize allocation per player as previously described. In one embodiment, each electronic gaming terminal is configured to show a player the proportion of the jackpot prize which could be won, based on their current bet size for that round, if the mystery triggered for that round. In yet another alternative embodiment, the electronic terminals may be communicable with a virtual game controller that uses an RNG and animated graphics to play and determine the outcome of the game. The electronic gaming terminals may comprise, for example: a display; a credit input mechanism operable to establish credits on the gaming machine (which could include at least one of a coin input chute, a bill collector, a card reader and a ticket reader); meters configured for monitoring credits established via the credit input mechanism and changes to the established credits due to play of the gaming machine, the meters including a credit meter to which credit input via the credit input mechanism is added and a win meter; a random number generator; a game play mechanism including a plurality of buttons configured for operation by a player to input a wager from the established credits and to initiate a play of a game; and a controller for communication with a central controller.

It will be appreciated in the aforementioned described embodiments where gaming terminals are used to place wagers on the game, that the table as previously described consists of both the dealer station or a virtual game, on which the game is dealt, and the associated players terminals on which players make their wagers, and contributions made to the mystery jackpot pool contingent on a game state event, relate to the game played at the dealer station or virtual game. A winning table relates to the players who made qualifying bets via their gaming terminals on the game from which the game state signal triggered the jackpot.

Although the afore-described embodiments were described in the context of a venue-based game it will be understood that alternative embodiments may involve players remotely participating in the game. For example, the gaming controller 20 could be configured to communicate over any suitable network such as an intranet, and/or to gaming systems provided through computing or other electronic devices, e.g. personal computers, PDAs, digital mobile devices, digital televisions, and the like, e.g. over the Internet or other suitable communications networks.

It will be understood that the embodiments described above should not be seen as being limited for play on a physical casino table and instead could readily be implemented as a screen-based game, e.g. as an Internet-based game or the like. In this regard an electronic game controller implemented by a computer server may be used to receive player bets, control game play and award jackpots.

One or more of the following advantages may arise from one or more embodiments of the invention as described herein. Embodiments of the present invention may further drive house revenues by enticing players to wager on games that they may not have otherwise due to the potential of a mystery jackpot being awarded to their table for any wager game played thereon. This is particularly advantageous for games such as Baccarat where players typically do not wager on every game and may sit out for several rounds of play or may decide to only make a bet when a certain pattern of preceding results have occurred. An associated behavior is where players wait for several hands to be played at the start of a new shoe before making their first bet. Players can also be influenced by other players’ betting behaviors at the table which may cause them to decide not to make a bet on a certain round. A main feature of an embodiment of the present invention is that for every game played out at the table, there is a chance the mystery jackpot will be triggered, even when no participating bets have been made. Furthermore, the mystery jackpot may be configured to hit frequently, as an example once a day, and sometimes a jackpot will be awarded to the table and then reversed as there were no qualifying bets made by players forthat round. When players observe that a jackpot was triggered and subsequently reversed, then they will be enticed to place qualifying bets on every round of play for fear of missing out on the jackpot prize.

Another advantage of the present invention and in particular the embodiment where players share a jackpot prize on a pro rata basis to the size of their bet (wager value), is that players will be enticed to increase their bet size in relation to any other players bets for that round of play, to increase their proportion of the jackpot prize, should it trigger for that round.

Another advantage of the present invention is the load balancing effect of a shared jackpot on numbers of players at each table. A casino typically schedules to open and staff a set number of tables for each gaming period to accommodate demand from players seeking to play games. Typically, with baccarat games as a non-limiting example, players tend to cluster and crowd around certain tables such that some tables are busy and other tables are less busy and sometimes empty. This player clustering behavior has a significant impact on operational efficiencies. The busy tables are more difficult to manage, and the game speed deteriorates, whereas at other tables there are fewer players making the operational overheads expensive. One effect of adding a shared mystery jackpot to baccarat tables is that players will realize that they will win a larger share of any triggered jackpot if they play at tables with few other players. By example, if a player seeks out an empty table and becomes the only player at the table who is making participating bets in the game, then should the jackpot be triggered, said player will win 100% of the jackpot prize. If there are two participating players at the table then the jackpot prize will be shared amongst them and so on. The effect of players seeking out less busy tables balances demand across all tables and improves operational efficiencies.

Another advantage of the present invention is the ability to control the percentage probability that a table, or a group of tables, has to win a mystery jackpot. This is achieved because it is the table which is associated with the jackpot contributions as opposed to player’s wagers. In the jackpot configuration module different contribution levels can be associated with different tables or table groupings. By way of example, if table A or table group A is configured to contribute $1.00 per game to the jackpot pool, whereas table B or table group B contributes $2.00 per game to the jackpot pool, then table B, or table group B has twice the probability to trigger a jackpot than table A or table group A. This allows for jackpot segmentation and targeting. As an example, a casino may wish to offer VIP tables a higher probability of winning the mystery jackpots than main gaming floor tables. Another example might be offering a higher probability of winning the mystery jackpots to certain game types which are more profitable to the casino because they have a higher house edge. Another example is to offer a greater probability of winning to tables with a higher minimum bet. It is the method used by the present invention, by associating jackpot contributions on a per game per table basis, that enables different tables or different groups of tables to have different probabilities of winning a jackpot.

Another advantage of the present invention is to define qualifying bets as specific bets which may be side bets or one bet from a set of bets offered. Preferably these bets would be bets with a higher house edge than other bets offered on the game and the opportunity to win a mystery jackpot would encourage players to play these bets in preference to other bets. As an example, the qualifying bets on a baccarat game could be the pairs bet or the tie bet. In the baccarat example these bets have a house edge around 10 to 15 percent compared to a house edge of between 1 and 2 percent for Player and Banker bets.

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. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.