EP0181420A1

EP0181420A1 - A target apparatus

Info

Publication number: EP0181420A1
Application number: EP84307732A
Authority: EP
Inventors: Julian Eason Bardo
Original assignee: JPM (AUTOMATIC MACHINES) Ltd; VIRAGATE Ltd
Current assignee: JPM (AUTOMATIC MACHINES) LIMITED
Priority date: 1984-11-08
Filing date: 1984-11-08
Publication date: 1986-05-21

Abstract

A target (4), such as a dart board, is intended to have a projectile of conductive material partially embedded therein. The target (4) is made of a plurality of separate mutually insulated conducting beds. An aerial (15) transmits a signal and a dart protruding from one bed will transfer part of the signal to that bed. The presence of the signal on the bed may be detected and utilised to determine the score attributable to the projectile.

Description

The present invention relates to a target apparatus, and more particularly relates to a target apparatus incorporating a target of the type into which a projectile may be embedded, with part of the projectile still protruding from the target. Examples of such targets are dart-boards and archery targets.
In this specification, the invention will be described with prime reference to a dartboard, but it is to be understood that the invention may be applied to other similar targets, such as an archery target, if the appropriate modifications are made.
Various attempts have been made to provide an automatic scoring dartboard. Some of these attempts have involved the use of mechanical devices, such as the arrangement described in British Patent Specification No. 1,370,609. In this arrangement when a dart hits the target, a member moves and an appropriate electronic signal is generated. The disadvantage with this type of target is that the target involves many moving parts, which can go wrong, and also the dart does not become embedded in the target in the same way that the dart would become embedded in an ordinary dartboard.
British Patent Specification No. 1,603,792 describes a different arrangement in which the dartboard is provided with a number of superimposed conducting layers, that are insulated from each other. As a dart becomes embedded in the dartboard the point of the dart interconnects the various layers, and consequently electric signals can be passed from one layer to another to provide an indication of the precise location of the dart. One disadvantage with this particular arrangement is that the conductive layers are formed of a conductive foam material. Thus the described dartboard does not have the same "feel" and does not have the same playing characteristics as a conventional dartboard. Also, in areas of the dartboard where the darts land frequently, for example the triple-twenty region, the foam is soon severely damaged by the points of the darts, and looses its conductive characteristics.
According to this invention there is provided a target apparatus comprising a target of the type into which a projectile of conductive material may be embedded with part of the projectile still protruding from the target, and an associated automatic scoring arrangement, the target being divided into a plurality of separate mutually insulated beds each associated with a predetermined score that can be obtained by a player or sportsman causing a projectile to become embedded in that bed, and an aerial or antenna transmitting electro magnetic radiation which can be received by a part of a projectile protruding from a bed, each bed incorporating electrically conductive means for leading any signal present on the bed to means for determining the score attributable to the projectile, embedded in the bed, which is receiving the radiation.
Preferably the target face is divided into a plurality of beds, which are formed from fibres that are, or have been treated to be, conductive at least on the outer surfaces thereof adjacent the face of the target, the fibres in each bed being insulated from the fibres in the adjacent beds.
Conveniently the target comprises a backing member and a plurality of fibres that extend normally to the backing member, the free ends of the fibres defining the front face of the target.
Advantageously the fibres are vegetable fibres that have been at least partly coated with metal or with conductive metal oxide.
Preferably the fibres have been coated with graphite by being treated with a liquid comprising a suspension of finely divided graphite.
Conveniently the fibres in adjacent beds constituting the target are insulated from each other by a separator member formed of insulating material and having at least one inner conductor, said inner conductor acting as an electric shield between the two beds.
Preferably each bed is connected to an appropriate input port of a multiplexer, the output of the multiplexer being fed to a detector/ discriminator means, the arrangement being such that the beds may be sequentially interrogated by the detector/discriminator means which detect and discriminate the amplitude of the signal transmitted by the aerial or antenna being received by the bed.
In one embodiment of the invention the output of the detector/ discriminator means is fed to a computer which stores the information and which compares the amplitude of the detected signal on each bed with the amplitude of the signal present on the bed during the preceding interrogation of the bed, the computer responding to a change in amplitude above a predetermined minimum threshold value to attribute an appropriate score to the player or sportsman then playing.
In another embodiment, means are provided for supplying a phase signal to the said aerial and means are provided for supplying an antiphase signal to the said beds, so that no response is produced when no projectile is embedded in the bed, the detector/discriminator means detecting the increase in phase signal received or detected when a dart becomes embedded in the said bed.
Preferably the target is mounted on means adapted to provide an output signal indicative of whenever there is an increment in the weight of the target, signals thus being provided whenever a projectile becomes embedded in the target, the output of the weight detecting means being passed to said computer.
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure I is a perspective view of a spider used in making a dartboard;
Figure 2 is an enlarged view of part of the spider with part thereof cut away;
Figure 3 is a perspective view of part of the dartboard with part cut away;
Figure 4 is a diagrammatic view of the apparatus ready for use; and
Figure 5 is a block diagram of one embodiment of the apparatus;
Figure 6 is a block diagram of another embodiment of the apparatus; and
Figures 7 and 8 show further details of the Figure 6 embodiment.

Figure I shows a structure that is termed a spider I. The spider I has the configuration of the wire framework that is conventionally mounted on the front face of a dartboard to divide the dartboard into various beds. The score attributed to any dart thrown at the dartboard depends upon the precise identity of the bed in which the dart becomes embedded.
The structure of the spider is illustrated in Figure 2. The spider is preferably of a moulded construction. Each part of the spider has a central conducting region 2. This may be a metallic component e.g. copper foil or aluminium located in position during the moulding process, but preferably the spider is moulded with recesses which are subsequently filled with a conducting material to form the conducting regions 2. The purpose of the conducting regions 2 will be described below. The conducting regions 2 are provided throughout the spider, and all the regions 2 are electrically interconnected.
Each part of the spider extends rearwardly from the front face, and the spider has a uniform depth. Each of the laterally facing parts of the spider are provided with a conducting element, such as a spray coating of copper, 3.
A conventional dartboard consists of a plurality of fibres of sisal which are bonded to, and which extend forwardly from a back board which may be of hardboard or chipboard. A dartboard 4, shown in Figure 3, for use in the presently described embodiments of the invention consists of a plurality of conductive fibres 5 which extend forwardly from a backing member 6. The spider I is located within the mass of the fibres and serves to separate the fibres in each bed from the fibres in adjacent beds. A dartboard of this type may be fabricated by substantially conventional techniques utilising conductive fibres. The fibres may be sisal fibres that have been coated with a waterproofing material and subsequently coated with a conductive material, for example by immersing in (or spraying with) or a suspension of graphite particles as sold under the Trade Mark "ELECTRODAG". The fibres are compressed whilst substantially parallel and are cut to have a planar end face. This is bonded to an appropriate backing sheet, which may be a temporary backing sheet having an aperture or perforated portions corresponding to the shape of the spider. The fibres are then cut again so that a plurality of short parallel fibre lengths remain bonded to the backing sheet. A hole is then cut in the assembly thus produced having a shape corresponding to that of the spider. The hole may be cut through the aperture or perforated portions of the backing sheet. The spider is then pressed into the hole to form separate beds in the target. The assembly may then, if desired, be bonded to a rigid permanent backing sheet.
Electric contacts are made with the electrically conducting core of the spider and with the various conducting elements on the laterally facing parts of the spider. This provides a separate electrical contact with each of the discrete beds of fibres. Instead of coating parts of the spider with conductive material conductive shims, eg. copper shims, may be slid between the spider and the fibres of each conductive bed. The spider may replace the conventional wire framework that divides the dartboard into separate beds, especially if the front face of the spider protrudes slightly from the front face of the dartboard.
At least one, and preferably two, loops of wire are mounted on or adjacent the front face of the dartboard. The loops are preferably insulated so that a dart that is embedded in the dartboard cannot contact the wire electrically. The first loop 7 is located at the outer periphery of the scoring area of the board and the second loop 8 is located at the boundary between the "triple" scoring beds and the innermost region of "single" scoring beds. An electrical connection is provided to the loops which act as an aerial, as will be described. The loops may, of course, form part of a conventional wire framwork if such a framework is provided, but in a preferred embodiment they are embedded in the appropriate parts of the spider being, of course, insulated from the conducting core 2 of the spider.
The dartboard 4 is mounted in position on a weight monitoring device 9. The device 9 may be located between the rear of the dartboard and the supporting wall, and serves to monitor the weight of the dartboard. Associated with the dartboard in the described embodiments is a display and control panel 10. The display has two display windows 11, 12 each to display the score of a respective player. The panel 10 also has some control buttons I to reset the apparatus and to enable players to choose the precise nature of the game to be played.
Figure 5 is a general block diagram of one embodiment of the invention.
A signal source 13 is provided which generates a suitable radio frequency signal at an appropriate peak-to-peak amplitude. At present, it is contemplated that a radio frequency of approximately 35 KH₂ and a peak-to-peak amplitude of approximately 5.5 volts will be employed. The signal is applied to an amplifier 14, and from the amplifier 14 the signal is led to an aerial 15 constituted by the above-described loops 7 and 8. The signal will thus be transmitted by the aerial 15.
The individual conductive beds of the dart board 4 are connected individually to the 88 input ports of a multiplexer 16 to enable each bed to be interrogated sequentially. The multiplexer is controlled by an address decoder 17 which in turn is associated with a computer 18.
The single output of the multiplexer 16 is connected, (optionally via a filter and/or amplifier circuit - not shown) to a detector/discriminator arrangement 19 which is intended to detect the presence of a signal from the signal source 13 as being received by the bed of the dartboard being interrogated by the multiplexer 16 at any instant, and to discrimate the level of the received signal. The output of the detector/discriminator 19 is fed to the computer 18.
A detector 20 is provided to detect a person when at the playing position. This may be a pressure switch under the carpet at the appropriate position, or may be a heat sensitive detector or, may be an ultrasonic device or any other appropriate arrangement. By monitoring the signal supplied from the detector 20 the computer can ascertain when a player has finished throwing his three darts and leaves the playing position, even if all three darts have not stuck in the dart board.
When the described device is in operation, when a player is detected at the playing position by the detector 20 the signal source generates a signal which is amplified and transmitted by the aerial 15. Initially the signal is detected by each conductive bed, and as the multiplexer sequentially interrogates the beds, the signal received by each bed is fed to the detector/discriminator. The presence of the signal is detected and the level or amplitude of the detected signal is discriminated. The relevant information is passed to the computer where the information is stored.
When the player throws the first dart, the dart becomes embedded in one bed on a dart board. Since the dart is conductive, the dart acts as an aerial, and consequently the amplitude of the signal, (as transmitted by the aerial 15) received by the bed in which the dart is embedded increases, relative to the level of the signal previously received by that bed. When the multiplexer next interrogates that particular bed, the increased level of signal is detected and discriminated. The computer is programmed to compare the amplitude of each discriminated signal on each bed with the previously stored value for the same bed, and when the signal shows an increase in excess of a predetermined tolerance, it is deemed that a dart has become embedded in that dartboard.
The weight detector 9 will confirm an increase in weight of the total dart board assembly, thus confirming that a dart has become embedded in the bed.
When the computer has determined the identity of the bed in which the dart has tended, it calculates the score, and causes the score to be displayed. The score may be displayed as an increasing total, each player thus starting with a score of "zero" displayed, the game ending when the winner reaches the score of "301" or "501" as may be appropriate. Alternatively the score may start at "301" or "501" for each player and may be reduced appropriately until the winner has a score of "zero".
When the second dart is thrown and becomes embedded in the board, the increase in the overall weight of the board will again be detected, and the beds will again be sequentially interrogated by the multiplexer 16. If the second dart is in a different bed from the first dart, an appropriate signal will be detected when that bed is interrogated. Even if the two darts are touching, signals will be received from two beds, but the amplitudes of the signals will not be the same as they would be if the darts are not touching. If the second dart enters the same bed as the first dart the amplitude of the signal detected by the detector/discriminator 19 when the multiplexer 16 interrogates the appropriate bed will be greater than the amplitude when only one dart was present in the bed.
When the third dart is thrown the procedure is repeated. If all three darts are in different beds signals will be detected when each of those beds is interrogated by the multiplexer 16, even if two or more of the darts are touching. If the third dart enters a bed already occupied by one of the first two darts, the signal level detected when that bed is interrogated will be greater when there was only one dart in the bed. If the third dart enters a bed that is already occupied by the first two darts, this will still be detected since even if the resultant increase in the signal detected by the detector/ disciminator 19 when that bed is interrogated is minimal, the fact that the dart is embedded in the board will be confirmed by the output from the weight detector 9, and the computer may, in such circumstances, be programmed to include that all three darts are in one bed.
When three darts have become embedded in the board, the player has finished his turn, and the computer will attribute the next three darts to the next player. In some cases, especially when the players are not very skilled, one or more darts may fail to stick in the dart board, or may fail even to hit the dart board. The player may then end his turn with, for example, only one or two darts stuck in the board. The detector 20 will detect when the player leaves the playing position, and the computer will treat that event as being indicative of the end of the turn of that player. Of course, in an alternative arrangement a "reset" button may be provided on the control panel.
The conducting regions 2 present in the spider serve to isolate the beds from each other, reducing the possibility of spurious signals being generated as a result of "cross-talk".
Figure 6 is a general block diagram of another embodiment of the invention in which items corresponding to the same items as in Figure 5 have the same reference numerals. In this embodiment, the signal from the signal source 13 is applied to an amplifying and multiplexing arrangement 21 which will be described in greater detail hereinafter. The arrangement 21 acts to apply the signal to the aerial 15 which thus transmits the signal. The multiplexer of the arrangement 21 is provided with appropriate controlling signals from the address decoder 17 which is controlled by the computer 18.
The signal from the signal source is also supplied to a second amplifying and multiplexing arrangement 22, the multiplexer of which is controlled by signals from the address decoder 17. This amplifying and multiplexing arrangement serves to supply to the beds of the dartboard antiphase signals which cancel out the transmitted signal received from the aerial by the bed of the dartboard that is being interrogated at that instant. The bed being interrogated is connected to the detector discriminator 19 to detect any signal present on the bed. However, since the signals provided from the amplifying and multiplexing arrangement 22 always cancel out the signals received from the aerial 15 when no dart is embedded in the board, no signal is detected from the bed in the absence of a dart.
Figure 7 shows the amplifying and multiplexing arrangement 21 in greater detail. The signal from the signal source 13 passes along lead 23 and is fed to each of the 88 inputs of an 88 to I multiplexer 24 by a respective variable phase lead network 25. The networks 25 are each adjusted to impart a respective phase lead to the output signal thereof when initially setting up the apparatus to compensate for any deviation from antiphase between the transmitted signal received by a bed from the aerial 15 and the signal applied thereto by the arrangement 22. The single output 27 of the multiplexer 24 is connected to the aerial 15. The multiplexer 24 of the arrangement shown in Figure 7 is supplied with control signals from the address decoder 17 through the lead 26.
Figure 8 illustrates in more detail the amplifying and multiplexing arrangement 22. The input signal from signal source 13 on lead 29 is fed to a I-to-88 multiplexer 30 via a phase retard circuit 31 which imparts a 90⁰ phase lag to the signal with unity gain and a phase inversion amplifier 32 which converts the signal into an antiphase signal. The multiplexer 30 is controlled by signals from the address decoder 17 which are supplied via the lead 32. Each output of the multiplexer 30 is connected to a respective attenuating network. Only one such network is shown in Figure 9, but the remaining eighty seven networks correspond. One output 34 of the multiplexer 30 is fed through a buffer 35 to the ends of the resistive element of a respective variable resistor 36. The other end of the resistor 36 is grounded. The slide of the variable resistor is connected to a respective bed of the dartboard for applying to the bed an attenuated signal which is in antiphase to the transmitted signal received from aerial 15 and which has the same amplitude as the transmitted signal received by the bed from the aerial.
During use of the embodiment described with reference to Figures 6 to 8, the described multiplexers are enabled appropriately by the address decoder 17 so that the beds are sequentially interrogated with a simultaneous energisation of the appropriate paths through the amplifying and multiplexing arrangements 21 and 22. The decoder 16 has a manual override to enable the various beds to be energised sequentially under manual control. This facilitates setting up the system since it enables the aerial and each bed to be energised for the period of time necessary to adjust the appropriate phase lead network 25 and variable resistor 36 to balance the transmitted signal received by the bed from the aerial and the signal applied to the bed by the arrangement 22.
The operation of the second embodiment of the invention during a game corresponds to that described with reference to Figures I to 5, except that a null output signal is delivered to the detector/discriminator 19 from a bed in the absence of a dart and the detector/discriminator serves to detect the increase in the output signal from the bed resulting from the increased signal received from the aerial 15 when a dart is embedded in the bed.
Whilst the invention has been described by way of example, many modifications may be effected without departing from the scope of the invention.

Claims

I. A target apparatus comprising a target of the type into which a projectile of conductive material may be embedded with part of the projectile still protruding from the target, and an associated automatic scoring arrangement, the target being divided into a plurality of separate mutually insulated beds each associated with a predetermined score that can be obtained by a player or sportsman causing a projectile to become embedded in that bed, and an aerial or antenna transmitting electro magnetic radiation which can be received by a part of a projectile protruding from a bed, each bed incorporating electrically conductive means for leading any signal present on the bed to means for determining the score attributable to the projectile, embedded in the bed, which is receiving the radiation.
2. A target according to claim I, the target face being divided into a plurality of beds, which are formed from fibres that are, or have been treated to be, conductive at least on the outer surfaces thereof adjacent the face of the target, the fibres in each bed being insulated from the fibres in the adjacent beds.
3. A target according to claim 2, comprising a backing member and a plurality of fibres that extend normally to the backing member, the free ends of the fibres defining the front face of the target.
4. A target according to claim 2 or 3, wherein the fibres are vegetable fibres that have been at least partly coated with metal or with conductive metal oxide.
5. A target according to claim 4 wherein the fibres have been coated with graphite by being treated with a liquid comprising a suspension of finely divided graphite.
6. A target according to claim 2 or any claim dependent thereon wherein the fibres in adjacent beds constituting the target are insulated from each other by a separator member formed of insulating material and having at least one inner conductor, said inner conductor acting as an electric shield between the two beds.
7. An apparatus according to any one of the preceding claims wherein each bed is connected to an appropriate input port of a multiplexer, the output of the multiplexer being fed to a detector/discriminator means, the arrangement being such that the beds may be sequentially interrogated by the detector/discriminator means which detect and discriminate the amplitude of the signal transmitted by the aerial or antenna being received by the bed.
8. A target according to claim 7, wherein the output of the detector/discriminator means is fed to a computer which stores the information and which compares the amplitude of the detected signal on each bed with the amplitude of the signal present on the bed during the preceding interrogation of the bed, the computer responding to a change in amplitude above a predetermined minimum threshold value to attribute an appropriate score to the player or sportsman then playing.
9. A target according to claim 7, wherein means are provided for supplying a phase signal to the said aerial and means are provided for supplying an antiphase signal to the said beds, so that no response is produced when no projectile is embedded in the bed, the detector/ discriminator means detecting the increase in phase signal received or detected when a dart becomes embedded in the said bed.
10. A target apparatus according to any one of the preceding claims wherein the target is mounted on means adapted to provide an output signal indicative of whenever there is an increment in the weight of the target, signals thus being provided whenever a projectile becomes embedded in the target, the output of the weight detecting means being passed to said computer.