Transmitter tag

A transmitter tag for a ball, the tag comprises a transmitter configured to issue a signal for location of the ball, a power source for powering the transmitter, activation means operable for activating the transmitter when the ball is in use, and deactivation means operable for remote manual deactivation of the transmitter after the ball is located.

The present invention relates to a transmitter tag, and more particularly but not limited to a transmitter tag for a golf ball.

Golf is a well known, and popular game in which a participant attempts to use a golf club to hit a golf ball into one of a series of holes in as few shots as possible. One issue associated with the game is the frequent loss of golf balls, which can occur. Lost or irretrievable balls result in the participant incurring penalty points thereby negating the objective of the game. Furthermore, the loss of balls adds to the financial cost of playing the game, and can result in a relatively large amount of much time being spent searching for the lost balls. The time spent searching for golf balls can also reduce the throughput of players on a golf course, thereby having a negative impact, not just on the participant, who has lost the ball but on other players also.

Solutions to help players locate golf balls have been proposed in the past. One such example comprises a golf ball, which flashes for a preset period after it has been struck. However, such systems rely on a line of sight between a player and the ball, which frequently isn't the case with lost balls. In order to conserve batteries the ball is designed to stop flashing after a relatively short period, typically 5 minutes or so. This means that if the ball is not located within that period the ball might not be found at all. Additionally, if the ball is located immediately after flashing is initiated, for example, on a putting green or the like, the flashing can be distracting either to the player taking the shot, or other players in the vicinity.

In another example, a golf ball is provided with an embedded passive radio frequency tag. The tag contains a microchip that responds to a signal transmitted from a locater device by returning a modified signal. The microchip has no independent power source, but instead operates off power taken from a carrier signal transmitted from the locator device. Thus, the device is inherently limited to a relatively short range (˜9 m).

It is an object of the present invention to provide a transmitter tag, which mitigates at least one of the above issues.

According to one aspect of the present invention there is provided a transmitter tag for a ball, the tag comprising: a transmitter configured to issue a signal for location of said ball; a power source for powering said transmitter; activation means operable for activating said transmitter when said ball is in use; and deactivation means operable for remote manual deactivation of said transmitter after said ball is located.

Preferably said activation means comprises an impact switch operable to activate said transmitter in response to said ball being struck.

Preferably said deactivation means comprises a magnetic switch operable to deactivate said transmitter in response to the presence of a magnetic field.

Preferably said magnetic switch is a Hall effect switch.

Preferably said transmitter is configured for issuing a signal comprising a series of pulses modulated with a carrier signal. This may be a periodic on/off key modulated ultra high frequency carrier signal.

Preferably, said signal is allocated to a specific carrier frequency, said frequency being configurable to provide an identifier for identifying said ball.

Preferably said issued signal has a duty cycle of less than 1%.

Preferably each pulse has a width in the region of 200 μs, and wherein one pulse is issued in the region of every 60 ms.

Preferably said transmitter comprises an oscillator for producing said carrier signal.

Preferably said oscillator comprises a surface acoustic wave resonator.

According to another aspect of the present invention there is provided a golf ball comprising the transmitter tag.

Preferably said golf ball comprises a substantially spherical core embedded concentrically within said golf ball, wherein said tag is embedded in said core, and wherein said core, tag, and golf ball share substantially the same centre of mass.

The invention has particular application for the location of golf balls. Hence, for the sake of clarity, the invention is described with particular reference to golf balls. It will be appreciated, however, that the invention has wider application than to golf balls alone.

InFIG. 1a golf ball having a transmitter tag is shown generally at10. The golf ball comprises a shell portion12, a core portion14, and a tag16.

The shell portion12generally comprises a hollow sphere of external dimensions and appearance corresponding to the standard requirements for golf balls. For example, at the time of filing the application, golf balls are required to have a minimum diameter of 1.68 inches. The external appearance may include, for example, the dimpled effect associated with maximising the distance that a ball of a particular weight will travel.

The core portion14is embedded for concentric centre of mass within the shell portion. The core14may be made of any material suitable for ensuring that the golf ball has a weight conforming to standard requirements, and for ensuring an acceptable balance and feel. For example, at the time of filing the application, golf balls are required to have a maximum weight of 1.62 ounces. An example of a suitable material for construction of the core portion14is a plastics material, such as polyurethane, whose density and other material characteristics (e.g. elasticity), may be manipulated to allow conformity of the golf ball both with appropriate rules, and with the expectations of players.

The materials of both the shell12and the core14are of sufficient durability, and resilient strength both to resist physical damage and/or deformity during the normal course of play, and to give the golf ball an acceptable lifespan.

The tag16is embedded for concentric centre of mass within the core. The tag16comprises a transmitter circuit configured for issuing a suitable signal for minimising power consumption while the transmitter is operational. In operation, the transmitted signal is received by a complementary receiver circuit, provided in a separate unit, for locating the transmitter tag and hence the golf ball in which it is embedded.

The shell12, the core14and the tag16are further arranged to ensure compliance with rules concerning spherical symmetry, initial velocity, the overall distance standard and similar rules.

InFIG. 2(a) a first embodiment of a transmitter circuit, suitable for implementation in the transmitter tag16, is shown generally at20. The transmitter circuit20is operable to transmit an amplitude shift key modulated signal, comprising an ultra high frequency (UHF) signal modulated by a periodic series of on/off pulses to produce periodic UHF carrier bursts. Each pulse is relatively short, thereby resulting in a pulsed signal having a correspondingly low mark space ratio and the transmitted signal having an equivalent duty cycle. Typically, for example, the duty cycle is less than ˜1%, the mark space ratio being less than ˜0.01. A typical pulse length, for example, is ˜200 μs for a period of 60 ms. Thus, the power consumption of the transmitter is minimised thereby prolonging battery life.

It will be appreciated that different tags may be provided with transmitter circuits in which the on/off keyed signal is allocated to a different carrier frequency. Similarly, the associated receiver may be configured for distinguishing between the frequencies thereby allowing a player to locate a ball having a specific identity. Thus, in a different embodiment of the invention, different frequencies could be used to identify different golf balls. The identification may be, for example, an electronic equivalent to the number printed on the side of a ball for visual identification purposes.

The transmitter circuit20comprises a power source22, activation means24, deactivation means26, a latching portion28, a boost portion30, oscillator means32, modulation means34, and antenna means36.

The power source22, is a conventional battery or the like arranged for providing a working voltage to the latching portion28, and the rest of the circuit. Typically, for example, the battery is a primary 3V lithium or the like.

The activation means24comprises a normally open switch, operable in the event of acceleration above a predefined level to switch temporarily from an open circuit or off state, to a short circuit or on state. Typically, for example, the switch comprises an impact, acceleration, or shock sensor, operable to switch temporarily from the off state, to the on state, in response to an acceleration between 1000 g and 5000 g, where g=9.8 m/s2. The switch may additionally be hemispherically omni-directional.

The latching portion28comprises a gated switch or circuit having a gate terminal38, an input terminal40, and an output terminal42. The latching portion28is operable to switch from a high impedance off state, between the input and output terminals40,42, to a low impedance on state, on the application of an appropriate voltage to the gate38. The latching portion28is further operable to latch, on switching to the on state, thereby maintaining the low impedance state after the applied gate voltage is removed. In operation, the latched condition is maintained until a short-circuit condition exists between the gate38and ground.

The activation means24is connected between the power source22, and the gate38of the latching portion28. The input terminal40of the latching portion28is connected directly to the power source22.

The deactivation means26, comprises a first terminal44and a second terminal46connected respectively to the gate terminal38via an internal connection in the latching portion28, and ground. The deactivation means26is operable to switch from a high impedance off state, to a low impedance on state, between the first and second terminals44,46, in the presence of a magnetic field of a suitable flux density. In the embodiment shown the deactivation means comprises a Hall effect switch, although it will be appreciated that other remotely influenced switching is possible.

The Hall effect switch comprises a micro-power omnipolar Hall effect switch. This allows a constant, polarity independent, magnetic field to be used to change the state of the hall switch. Hence, a simple, permanent magnetic source may be used to deactivate the device thereby reducing cost and complexity. A permanent magnet could, for example, be incorporated into the hand held receiver unit to allow for ball de-activation.

The Hall effect switch also incorporates an internally controlled clocking mechanism to cycle power to the Hall element and analogue processing circuits. The clocking mechanism serves to place the high current consuming portions of the circuit into a “Sleep” mode. Periodically the device is “Awakened” by internal logic, and the magnetic flux from the Hall element evaluated against predefined thresholds. If the flux density is above or below these thresholds then the output transistor is driven to change state accordingly. While in the “Sleep” cycle the output transistor remains latched in its previous state. Thus, the Hall effect switch is optimized for extended operating lifetime in battery powered systems.

Power for operation of the Hall effect switch26is provided, when the latching portion28is latched, from the output terminal42. Thus, when the latching portion28is not latched the Hall effect switch26does not consume power.

Hence, in operation, when the golf ball is struck the activation means24switches to the on state, thereby activating the latching portion28, such that the voltage at the output terminal42rises to that of the input terminal40, where it is maintained due the latching action of the latching portion28. Power is therefore supplied to the Hall effect switch26, via the output terminal42. Thus, when a magnetic field of suitable flux density is applied to the Hall effect switch26, the deactivation means26switches to the on state thereby short-circuiting the gate38to ground via the latching portion28, hence de-latching the latching portion28. After de-latching the latching portion28switches back to the off state thereby isolating the output terminal42from the input terminal40, and hence the power source22.

The boost portion30comprises an input and an output, and is operable to boost the voltage applied to the input, to yield a higher working voltage at the output. In the embodiment shown the boost portion comprises a DC-DC boost converter suitable for providing a sufficient output voltage for driving the oscillator and modulation means32,34. Typically, for example, the voltage output is ˜9V. It will be appreciated that alternatively, or additionally, additional voltage may be provided by providing at least one lithium power cell or the like, in addition to the power source22.

The output terminal42, of the latching portion28provides an input to the power boost portion30. Hence, in operation, when the latching portion28is latched the voltage of the power source22is applied to the input of the boost converter30, thereby resulting in a boosted voltage at the output.

The oscillator and modulator means32,34are arranged for powering by the boosted voltage, in operation, when the latching portion is latched.

The oscillator means32comprises a UHF radio frequency oscillator configured for providing a predefined UHF carrier signal. The modulator means comprises an on/off key modulator arranged to modulate the carrier signal with a signal comprising a periodic series of on/off pulses. Thus, in operation the transmitter produces an associated on/off key modulated signal comprising UHF carrier bursts, which it then transmits via the antenna means36.

The UHF oscillator32may comprise any suitable oscillator. Typically, for example, the oscillator comprises a single port surface acoustic wave (SAW) resonator operating at an appropriate frequency. The SAW resonator is particularly advantageous because it provides a good degree of frequency stability when subject to excessive mechanical shock of the type the golf ball is likely to receive during play. Typically, for example, a SAW resonator exhibits acceptable frequency stability at accelerations of the order 80000 g.

The antenna means comprises an omni-directional antenna operable to radiate the UHF carrier bursts in all directions.

Hence, in operation, when the golf ball is struck the activation means24switches to the on state, and the latching portion28latches thereby supplying the input of the boost converter, and Hall effect switch with power from the power source22. Thus, the boost converter provides the boosted voltage to the oscillator32and the modulator34and thus the transmitter begins to transmit the on/off key modulated signal.

In order to switch off the transmitter, a user brings the ball into the proximity of a magnetic field, thereby activating the Hall effect switch to de-latch the latching portion, thereby isolating the boost converter. Thus, the transmission of UHF bursts is stopped and power consumption reduced substantially to zero.

Hence, the deactivation means is manually operable to deactivate the transmitter. It will be appreciated that in addition to the manually operable switch, the deactivation means may further comprise a time delay switch, which automatically switches off the transmitter after a pre-determined delay, thereby avoiding undue power loss in the unlikely event that the transmitter is accidentally switched on.

The transmitter circuit is designed to comply with appropriate statutory and other requirements such as, for example, FCC regulations.

InFIG. 2(b) a second embodiment of a transmitter circuit, suitable for implementation in the transmitter tag16, is shown generally at120. The transmitter circuit120is similar to the circuit ofFIG. 2(a) and will be described to highlight the main differences. Like the first embodiment the transmitter circuit120is operable to transmit an amplitude shift key modulated signal as generally described previously.

Like the transmitter circuit20the circuit120comprises a power source122, activation means124, deactivation means126, a latching portion128, oscillator means132, modulation means134, and antenna means136. The circuit120, however, does not include a boost converter arrangement, and the rest of the circuit is modified accordingly.

The absence of the DC-DC boost has the advantage of reduced complexity and cost, and is particularly advantageous for applications where the maximum finding range is limited to between ˜50 m and 60 m.

The power source122, latching portion128, oscillator means132, modulation means134and antenna means are generally arranged and configured as described with reference toFIG. 2(a) and will not be described again in detail.

As described previously, the latching portion128comprises a gated switch or circuit having a gate terminal138, an input terminal140, and an output terminal142. Similarly, the deactivation means126, comprises a Hall effect switch having a first terminal144and a second terminal146connected respectively to the gate terminal138of the latching portion128, and ground.

In the absence of the boost converter, the oscillator and modulator means132,134are powered directly from the output terminal142, of the latching portion128, when the latching portion is latched.

Furthermore, unlike the embodiment ofFIG. 2(a), the activation means124comprises a standard ceramic resonator that uses the mechanical resonance of piezoelectric ceramics (generally, lead zirconium titanate or PZT) in order to produce the appropriate voltage at the gate138when subjected to a predefined level of acceleration. Typically, for example, the activation means124comprises a standard ceramic resonator configured to produce a voltage of sufficient amplitude to induce the required change in the impedance of the latching portion128, in response to an acceleration between 1000 g and 5000 g where g=9.8 m/s2. For example, the ceramic resonator may have a resonant frequency of 2 MHz to 16 MHz. The ceramic resonator may additionally be hemispherically omni-directional in X, Y and Z planes.

The activation means124is connected between ground and the gate terminal138of the latching portion128. The input terminal140of the latching portion128is connected directly to the power source122.

Hence, in operation, when the golf ball is struck the ceramic resonator124produces an appropriate voltage, thereby activating the latching portion128, such that the voltage at the output terminal142rises to that of the input terminal140, where it is maintained due the latching action of the latching portion128. Power is therefore supplied to the Hall effect switch126, via the output terminal142. Thus, when a magnetic field of suitable flux density is applied to the Hall effect switch126, the deactivation means126switches to the on state thereby short-circuiting the gate138to ground via terminals144and146of the Hall effect switch126, hence de-latching the latching portion128. After de-latching the latching portion128switches back to the off state thereby isolating the output terminal142from the input terminal140, and hence the power source122.

As described previously, the oscillator means132comprises a UHF radio frequency oscillator configured for providing a predefined UHF carrier signal. The modulator means134comprises an on/off key modulator arranged to modulate the carrier signal with a signal comprising a periodic series of on/off pulses.

Hence, in operation, when the golf ball is struck, the ceramic resonator124produces the required voltage at gate terminal138, and the latching portion128latches thereby supplying the input of the Hall effect switch126, the oscillator132and the modulator134with power from the power source122. Thus the transmitter begins to transmit the on/off key modulated signal.

In order to switch off the transmitter, a user brings the ball into the proximity of a magnetic field, thereby activating the Hall effect switch126to de-latch the latching portion128, thereby isolating the UHF oscillator132, and the modulator134from the power source122. Thus, the transmission of UHF bursts is stopped and power consumption reduced substantially to zero as described with reference toFIG. 2(a)

InFIG. 3a receiver circuit for receiving the signal transmitted by the transmitter circuit ofFIG. 2(a) or2(b) is shown generally at50. The receiver50is operable to receive the on/off key modulated signal, to recover the signal, and to provide an indication of its strength.

The receiver circuit50forms an amplitude shift key (ASK) superheterodyne receiver. Superheterodyne receivers are well known and hence the circuit will not be described in detail other than to further illustrate the invention.

The receiver50comprises, an antenna52, a first filter portion54, a mixer portion56, a local oscillator portion58, a second filter portion60, a demodulator portion62, peak detection means64, and indicator means66.

The antenna52is operable to receive the on/off key modulated signal transmitted by the golf ball. In the embodiment described the antenna52comprises an omni-directional antenna for reasons of practicality and cost efficiency. However, it will be appreciated that the antenna may alternatively be a directional antenna for assisting directional location of the golf ball emitting the modulated signal.

The first filter portion54comprises a band pass filter configured for filtering and amplifying the signal received by the antenna such that only the UHF frequency corresponding to the carrier of the modulated signal is amplified.

The oscillator means58comprises a UHF radio frequency oscillator configured for providing a second carrier signal. The mixer portion56is configured to heterodyne the filtered signal with the second carrier signal, produced by the oscillator portion58, to generate a lower sideband at a beat frequency known as the intermediate frequency. The intermediate frequency is substantially equal to the difference between the frequencies of the second carrier and the carrier of the modulated signal.

The second filter portion60is configured to further filter and amplify the heterodyned signal for subsequent demodulation. The demodulator portion62is operable to amplitude demodulate the output of the second filter portion60to recover the on/off key encoded signal transmitted by the transmitter tag in the golf ball.

The peak voltage of the recovered signal is indicative of the signal strength of the received signal, and hence the distance of the golf ball containing the transmitter tag from the receiver. The peak detection means64comprises a peak detector operable to detect the peak voltage of the recovered on/off key encoded signal and to convert it into a corresponding DC voltage. The peak detection means64comprises a high impedance unity gain amplifier having a diode isolated output. The amplifier is configured to have a suitable bandwidth for the intended application. A parallel capacitor, resistor arrangement is connected to the amplifier, the arrangement having a time constant sufficient to convert the on/off key recovered signal into a DC voltage. The DC voltage is fed into a further high impedance unity gain amplifier thereby producing a buffered output suitable for driving the indicator means66. The buffered DC voltage is thus indicative of the received signal strength, and hence the distance of the golf ball incorporating the transmitter tag from the receiver.

The indicator means66comprises means for providing a visual and/or audible indication of signal strength to a user.

The entire circuit is powered by an appropriate power source VCC.

An example of a typical hand held receiver unit is shown inFIG. 4generally at70. The receiver unit incorporates the receiver circuit50ofFIG. 3and a switch72for switching power to the circuit on and off as required. In the hand held unit ofFIG. 4the indicator means66is shown as an analogue coil indicator. It will be appreciated, however, that the indicator means may comprise any suitable means for indicating signal strength to the user. For example, the indicator means may alternatively or additionally comprise a digital display, an audible pitched output, an indicator bar or the like.

Hence, in operation, when a golf ball containing the transmitter tag is struck the tag begins transmitting an on/off key modulated signal. A user then uses the receiver unit70to pick up the transmitted signal and to give an indication of the associated received signal strength. The user then moves generally toward the area where he thinks the ball may have landed. If the indicator means66indicates that the signal strength is increasing the user knows that he is getting closer to the ball. On the other hand if the signal strength decreases the user knows that he is getting further away from the ball and can change direction accordingly. In this manner the user can find the ball quickly and easily without distracting other players.

After the ball is found the user deactivates the transmitter by putting a magnet of appropriate field strength near the golf ball. Conveniently, the golf ball may be provided with a storage container, of suitable dimensions for storing at least one golf ball, in which a suitable magnet is incorporated for ensuring that stored balls cannot start to transmit accidentally. Such a container would also mitigate against a user forgetting to deactivate the transmitter tag after finishing with the ball.

The use of a transmitter tag of the type described allows for a relatively large range, without contravening associated regulations, and without undue power consumption. Typically, for example, the transmitter tag of the second embodiment has a range in the region of 60 m, and a life span exceeding 200 hours in continuous operation.