TABLES

BACKGROUND OF THE PRESENT INVENTION

1. FIELD OF THE INVENTION

This invention relates to apparatus for printing quasi random number tables and has been devised particularly though not solely for printing tables for games of chance.

2. BACKGROUND ART

It is well known to provide tables of apparently random numbers for use in playing games of chance, such as bingo or various other games requiring the selection of a number of "winning numbers" from a table of such numbers. Further adaptations of these games require a winning combination incorporating, for example, three numbers the same in a row or three "prizes" of the same value alongside three numbers drawn from a selection of such numbers and announced or otherwise published.

In fact these tables are seldom true random number tables but incorporate a very large number of variables which are eventually repeated after a large number of tables have been printed. To the end user, however, each table appears to incorporate a matrix of apparently random numbers and is referred to throughout this specification as a "quasi random number table".

It has also been known to use such tables in which "prizes" are covered by a silvered layer rendering the prize values invisible until the silver layer is scratched off. Such games are commonly called "scratch bingo games". It has been a disadvantage in the past that the cards of quasi random number tables incorporating silvered coatings used in scratch bingo games have been time consuming and difficult to print, requiring a number of printing runs and considerable handling and collating.

It is therefore an object of the present invention to provide apparatus for printing quasi random number tables which will obviate or minimize the foregoing disadvantages in a simple yet effective manner, or which will at least provide the public with a useful choice.

SUMMARY OF THE PRESENT INVENTION

The invention consists in apparatus for printing quasi-random number tables (as herein defined) comprising a rotogravure printing press having at least two printing stations, characterized by the provision of at least two of said stations in the form of table printing stations incorporating printing cylinders having different circumferences, the circumference of each station being a multiple of a basic pitch value, each table printing cylinder being arranged to print one or more rows or columns of numbers arrayed in a matrix together with the rows or columns of numbers printed by the other table printing station. Preferably the circumference of each cylinder is determined by the basic pitch value multiplied by a prime number.

In one form of the invention the table printing cylinders at the table printing stations include a pair of table printing cylinders having different circumferences, each one of the pair of table printing cylinders being arranged to print a plurality of rows of numbers, the numbers in each row being spaced from one another and interspaced with numbers printed from the other of the pair of table printing cylinders.

In an alternative form of the invention each one of the table printing cylinders is arranged to print at least one column of numbers incorporating a predetermined number of numbers therein different from the number of numbers printed in a column by another of the said cylinders, the columns of numbers being arranged alongside one another in a predetermined matrix.

Preferably one or more background printing cylinders are provided, arranged to print background frameworks and/or supporting artwork in conjunction with the quasi-random number tables.

Preferably the rotogravure press is provided with a further roller adapted to print a removable coating over numbers printed by the table printing cylinders.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagrammatic view of a 6 station rotogravure press incorporating random number table printing cylinders according to the invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

This invention is intended to print quasi random number tables in a similar manner to the method described in my co-pending Australian patent application PI 1054 and also in my granted U.S. Patents 4,541,333 and 4,601,239. This specification however describes a variation on the printing method to adapt the method to use with a rotogravure printing press. Rather than having the printing cylinders arrayed around a central impression drum as is the case in the flexographic press described in the above referenced specifications, the rotogravure press locates each cylinder in a separate printing station located one after the other along the web of paper or film to be printed.

The quasi random number table printing system can be applied to a rotogravure press provided that each station has its own registration capacity and can be operated with different circumference printing cylinders on each station. The control- of registration of the quasi random number table system on a rotogravure press is not by a common drive gear as on a flexographic press but by the use of electronic controls used in setting registration equipment.

Each station has a different size engraved printing cylinder, and the cylinder sizes are selected according to the criterion described in the above referenced patent specifications.

For example as shown in the accompany drawing, the successive cylinders may have their circumferences as multiples of prime gradients such as 23, 19, 17, 13, 11, and 7. Alternatively non-prime and prime gradients may be used together such as a succession of cylinders wherein the circumferences are multiples of a prime gradient as follows;

22, 14, 10, 12, 23, 19, 17, and 13. Up to ten stations can be available on large rotogravure presses and it is possible to include one or more flexographic printing stations within the mix of rotogravure stations.

In addition to having the same size gradients around the circumference of the cylinder, each gradient has engraved into the edge of the cylinder image a registration mark. This registration mark is picked up by the photoelectric cell of the insetting equipment of that printing station. Each station and each printing cylinder have the same size gradients with a different number of gradients on each station printing cylinder.

The quasi random number tables system of using different size cylinders is controlled by a photoelectric cell picking up the registration marks on every gradient on each printing cylinder on each station of the rotogravure press. In normal use of a rotogravure press, with equal size cylinders at each station, the insetting electronics would be reacting to one registration mark on each cylinder and having an entire rotation of the cylinder to readjust and stay in register. The printing registration of this system of different size cylinders is controlled by the insetting electronics only compensating after twenty registration marks on each cylinder have passed the photoelectric cell. The purpose of this is to prevent the fine adjustment of the press registration equipment overcompensating too often to each small gradient and causing web breaks and other issues associated with overcompensation by the insetting equipment.

Still referring to Figure 1, each cylinder has formed thereon a plurality of registration marks 14 such as the registration marks on cylinder 23. In the preferred embodiment, each registration mark has the same pitch gradient and each cylinder has a number of registration marks equal to its individual pitch ratio. Thus, for example, cylinder 23 has 23 registration marks, cylinder 19 has 19 registration marks, and so on. A photoelectric cell 10 is disposed adjacent each cylinder and is utilized to detect each registration mark on the cylinder. Upon detection of each registration mark, the photoelectric cell provides a signal to motor controller 11. The motor controller 11 outputs a speed control signal 12 to its associated cylinder to speed up or slow down the cylinder depending on the timing of the occurrence of the registration marks.

In the past, equal sized cylinders have employed a single registration mark with synchronization occurring upon each detection of the mark. However, since the cylinders of the present invention each have a plurality of registration marks, it is preferred to synchronize only after a certain number of marks have been detected. In the preferred embodiment of the present invention, synchronization occurs after the detection of twenty registration marks. Thus, each motor controller includes a counter for enabling the output of a control signal 12 only after 20 marks have been detected. If desired, the motor controllers can be ganged together in parallel so that updating of all cylinders may be achieved in a consistent manner. In an alternate embodiment, the output of all photoelectric cells is coupled to a single motor controller which outputs a plurality of control signals to the individual cylinders. Although only a single photoelectric cell/motor controller assembly is illustrated in Figure 1, it is understood that each cylinder has an associated cell/ controller assembly in the preferred embodiment.

The method described above can be applied to the printing of any substrates commonly printed by the gravure method, including but not limited to paper, supported foil, polypropylene, and polyethylene films. Rub-off or "scratch" ink can be applied as described in the previous above referenced patent specifications.