[0001] The present invention relates to a transmitter tag, and more particularly but not
limited to a transmitter tag for a golf ball.
[0002] 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.
[0003] 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.
[0004] 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 (~9m).
[0005] It is an object of the present invention to provide a transmitter tag, which mitigates
at least one of the above issues.
[0006] 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.
[0007] Preferably said activation means comprises an impact switch operable to activate
said transmitter in response to said ball being struck.
[0008] Preferably said deactivation means comprises a magnetic switch operable to deactivate
said transmitter in response to the presence of a magnetic field.
[0009] Preferably said magnetic switch is a Hall effect switch.
[0010] 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.
[0011] Preferably, said signal is allocated to a specific carrier frequency, said frequency
being configurable to provide an identifier for identifying said ball.
[0012] Preferably said issued signal has a duty cycle of less than 1%.
[0013] Preferably each pulse has a width in the region of 200µs, and wherein one pulse is
issued in the region of every 60ms.
[0014] Preferably said transmitter comprises an oscillator for producing said carrier signal.
[0015] Preferably said oscillator comprises a surface acoustic wave resonator.
[0016] According to another aspect of the present invention there is provided a golf ball
comprising the transmitter tag.
[0017] 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.
[0018] An embodiment of the invention will now be described by way of example only with
reference to the attached figures in which:
FIG 1 shows a cut-away 3D view of a transmitter tag according to the invention, installed
in a golf ball;
FIG 2(a) is a block diagram of a first embodiment of the transmitter tag of figure
1;
FIG 2(b) is a block diagram of a second embodiment of the transmitter tag of figure
1)
FIG 3 is a block diagram of an Amplitude Shift Key Superheterodyne receiver for receiving
signals transmitted from the transmitter tag of figure 1; and
FIG 4 show a hand held unit into which the Amplitude Shift Key Superheterodyne receiver
of figure 3 may be incorporated.
[0019] 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.
[0020] In figure 1 a golf ball having a transmitter tag is shown generally at 10. The golf
ball comprises a shell portion 12, a core portion 14, and a tag 16.
[0021] The shell portion 12 generally 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.
[0022] The core portion 14 is embedded for concentric centre of mass within the shell portion.
The core 14 may 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 portion 14 is 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.
[0023] The materials of both the shell 12 and the core 14 are 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.
[0024] The tag 16 is embedded for concentric centre of mass within the core. The tag 16
comprises 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.
[0025] The shell 12, the core 14 and the tag 16 are further arranged to ensure compliance
with rules concerning spherical symmetry, initial velocity, the overall distance standard
and similar rules.
[0026] In figure 2(a) a first embodiment of a transmitter circuit, suitable for implementation
in the transmitter tag 16, is shown generally at 20. The transmitter circuit 20 is
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 ~200µs for a period of 60ms. Thus, the power consumption of the transmitter
is minimised thereby prolonging battery life.
[0027] 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.
[0028] The transmitter circuit 20 comprises a power source 22, activation means 24, deactivation
means 26, a latching portion 28, a boost portion 30, oscillator means 32, modulation
means 34, and antenna means 36.
[0029] The power source 22, is a conventional battery or the like arranged for providing
a working voltage to the latching portion 28, and the rest of the circuit. Typically,
for example, the battery is a primary 3V lithium or the like.
[0030] The activation means 24 comprises 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 1000g and 5000g,
where g = 9.8 m/s
2. The switch may additionally be hemispherically omni-directional.
[0031] The latching portion 28 comprises a gated switch or circuit having a gate terminal
38, an input terminal 40, and an output terminal 42. The latching portion 28 is operable
to switch from a high impedance off state, between the input and output terminals
40, 42, to a low impedance on state, on the application of an appropriate voltage
to the gate 38. The latching portion 28 is 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 gate 38 and ground.
[0032] The activation means 24 is connected between the power source 22, and the gate 38
of the latching portion 28. The input terminal 40 of the latching portion 28 is connected
directly to the power source 22.
[0033] The deactivation means 26, comprises a first terminal 44 and a second terminal 46
connected respectively to the gate terminal 38 via an internal connection in the latching
portion 28, and ground. The deactivation means 26 is operable to switch from a high
impedance off state, to a low impedance on state, between the first and second terminals
44, 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.
[0034] 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.
[0035] 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.
[0036] Power for operation of the Hall effect switch 26 is provided, when the latching portion
28 is latched, from the output terminal 42. Thus, when the latching portion 28 is
not latched the Hall effect switch 26 does not consume power.
[0037] Hence, in operation, when the golf ball is struck the activation means 24 switches
to the on state, thereby activating the latching portion 28, such that the voltage
at the output terminal 42 rises to that of the input terminal 40, where it is maintained
due the latching action of the latching portion 28. Power is therefore supplied to
the Hall effect switch 26, via the output terminal 42. Thus, when a magnetic field
of suitable flux density is applied to the Hall effect switch 26, the deactivation
means 26 switches to the on state thereby short-circuiting the gate 38 to ground via
the latching portion 28, hence de-latching the latching portion 28. After de-latching
the latching portion 28 switches back to the off state thereby isolating the output
terminal 42 from the input terminal 40, and hence the power source 22.
[0038] The boost portion 30 comprises 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
means 32, 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 source 22.
[0039] The output terminal 42, of the latching portion 28 provides an input to the power
boost portion 30. Hence, in operation, when the latching portion 28 is latched the
voltage of the power source 22 is applied to the input of the boost converter 30,
thereby resulting in a boosted voltage at the output.
[0040] The oscillator and modulator means 32,34 are arranged for powering by the boosted
voltage, in operation, when the latching portion is latched.
[0041] The oscillator means 32 comprises 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 means 36.
[0042] The UHF oscillator 32 may 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
80000g.
[0043] The antenna means comprises an omni-directional antenna operable to radiate the UHF
carrier bursts in all directions.
[0044] Hence, in operation, when the golf ball is struck the activation means 24 switches
to the on state, and the latching portion 28 latches thereby supplying the input of
the boost converter, and Hall effect switch with power from the power source 22. Thus,
the boost converter provides the boosted voltage to the oscillator 32 and the modulator
34 and thus the transmitter begins to transmit the on/off key modulated signal.
[0045] 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.
[0046] 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.
[0047] The transmitter circuit is designed to comply with appropriate statutory and other
requirements such as, for example, FCC regulations.
[0048] In figure 2(b) a second embodiment of a transmitter circuit, suitable for implementation
in the transmitter tag 16, is shown generally at 120. The transmitter circuit 120
is similar to the circuit of figure 2(a) and will be described to highlight the main
differences. Like the first embodiment the transmitter circuit 120 is operable to
transmit an amplitude shift key modulated signal as generally described previously.
[0049] Like the transmitter circuit 20 the circuit 120 comprises a power source 122, activation
means 124, deactivation means 126, a latching portion 128, oscillator means 132, modulation
means 134, and antenna means 136. The circuit 120, however, does not include a boost
converter arrangement, and the rest of the circuit is modified accordingly.
[0050] 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 ~50m and 60m.
[0051] The power source 122, latching portion 128, oscillator means 132, modulation means
134 and antenna means are generally arranged and configured as described with reference
to figure 2(a) and will not be described again in detail.
[0052] As described previously, the latching portion 128 comprises a gated switch or circuit
having a gate terminal 138, an input terminal 140, and an output terminal 142. Similarly,
the deactivation means 126, comprises a Hall effect switch having a first terminal
144 and a second terminal 146 connected respectively to the gate terminal 138 of the
latching portion 128, and ground.
[0053] In the absence of the boost converter, the oscillator and modulator means 132, 134
are powered directly from the output terminal 142, of the latching portion 128, when
the latching portion is latched.
[0054] Furthermore, unlike the embodiment of figure 2(a), the activation means 124 comprises
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 gate 138 when subjected to a predefined level of acceleration. Typically, for
example, the activation means 124 comprises a standard ceramic resonator configured
to produce a voltage of sufficient amplitude to induce the required change in the
impedance of the latching portion 128, in response to an acceleration between 1000g
and 5000g where g = 9.8 m/s
2. 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.
[0055] The activation means 124 is connected between ground and the gate terminal 138 of
the latching portion 128. The input terminal 140 of the latching portion 128 is connected
directly to the power source 122.
[0056] Hence, in operation, when the golf ball is struck the ceramic resonator 124 produces
an appropriate voltage, thereby activating the latching portion 128, such that the
voltage at the output terminal 142 rises to that of the input terminal 140, where
it is maintained due the latching action of the latching portion 128. Power is therefore
supplied to the Hall effect switch 126, via the output terminal 142. Thus, when a
magnetic field of suitable flux density is applied to the Hall effect switch 126,
the deactivation means 126 switches to the on state thereby short-circuiting the gate
138 to ground via terminals 144 and 146 of the Hall effect switch 126, hence de-latching
the latching portion 128. After de-latching the latching portion 128 switches back
to the off state thereby isolating the output terminal 142 from the input terminal
140, and hence the power source 122.
[0057] As described previously, the oscillator means 132 comprises a UHF radio frequency
oscillator configured for providing a predefined UHF carrier signal. The modulator
means 134 comprises an on/off key modulator arranged to modulate the carrier signal
with a signal comprising a periodic series of on/off pulses.
[0058] Hence, in operation, when the golf ball is struck, the ceramic resonator 124 produces
the required voltage at gate terminal 138, and the latching portion 128 latches thereby
supplying the input of the Hall effect switch 126, the oscillator 132 and the modulator
134 with power from the power source 122. Thus the transmitter begins to transmit
the on/off key modulated signal.
[0059] 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 126 to de-latch the
latching portion 128, thereby isolating the UHF oscillator 132, and the modulator
134 from the power source 122. Thus, the transmission of UHF bursts is stopped and
power consumption reduced substantially to zero as described with reference to figure
2(a)
[0060] In figure 3 a receiver circuit for receiving the signal transmitted by the transmitter
circuit of figure 2(a) or 2(b) is shown generally at 50. The receiver 50 is operable
to receive the on/off key modulated signal, to recover the signal, and to provide
an indication of its strength.
[0061] The receiver circuit 50 forms 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.
[0062] The receiver 50 comprises, an antenna 52, a first filter portion 54, a mixer portion
56, a local oscillator portion 58, a second filter portion 60, a demodulator portion
62, peak detection means 64, and indicator means 66.
[0063] The antenna 52 is operable to receive the on/off key modulated signal transmitted
by the golf ball. In the embodiment described the antenna 52 comprises 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.
[0064] The first filter portion 54 comprises 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.
[0065] The oscillator means 58 comprises a UHF radio frequency oscillator configured for
providing a second carrier signal. The mixer portion 56 is configured to heterodyne
the filtered signal with the second carrier signal, produced by the oscillator portion
58, 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.
[0066] The second filter portion 60 is configured to further filter and amplify the heterodyned
signal for subsequent demodulation. The demodulator portion 62 is operable to amplitude
demodulate the output of the second filter portion 60 to recover the on/off key encoded
signal transmitted by the transmitter tag in the golf ball.
[0067] 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 means 64 comprises 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 means 64 comprises 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/offkey 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 means 66. 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.
[0068] The indicator means 66 comprises means for providing a visual and/or audible indication
of signal strength to a user.
[0069] The entire circuit is powered by an appropriate power source VCC.
[0070] An example of a typical hand held receiver unit is shown in figure 4 generally at
70. The receiver unit incorporates the receiver circuit 50 of figure 3 and a switch
72 for switching power to the circuit on and off as required. 1rx the hand held unit
of figure 4 the indicator means 66 is 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.
[0071] 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
unit 70 to 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 means 66 indicates 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.
[0072] 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.
[0073] 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 60zn, and a life span exceeding 200 hours in continuous operation.
1. 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.
2. A tag as claimed in claim 1 wherein said activation means comprises an impact switch
operable to activate said transmitter in response to said ball being struck.
3. A tag as claimed in claim 2 wherein said impact switch is operable to produce a voltage
depending on acceleration induced when the ball is struck.
4. A tag as claimed in claim 3 wherein said impact switch comprises a ceramic based resonator.
5. A tag as claimed in any preceding claim wherein said deactivation means comprises
a magnetic switch operable to deactivate said transmitter in response to the presence
of a magnetic field.
6. A tag as claimed in claim 5 wherein said magnetic switch is a Hall effect switch.
7. A tag as claimed in claim 5 or 6 wherein said magnetic switch is an omnipolar.
8. A tag as claimed in any of claims 5 to 7 wherein said magnetic switch has an internal
clocking mechanism.
9. A tag as claimed in any preceding claim wherein said transmitter is configured for
issuing a signal comprising a series of pulses modulated with a camel signal.
10. A tag as claimed in claim 9 wherein said signal is allocated to a specific carrier
frequency, said frequency being configurable to provide an identifier for identifying
said ball.
11. A tag as claimed in claim 9 wherein said issued signal has a duty cycle of less than
1 %.
12. A tag as claimed in claim 9 wherein each pulse has a width in the region of 200µs,
and wherein one pulse is issued in the region of every 60ms.
13. A tag as claimed in any of claims 9 to 12 wherein said transmitter comprises an oscillator
for producing said carrier signal.
14. A tag as claimed in claim 13 wherein said oscillator comprises a surface acoustic
wave resonator.
15. A transmitter tag substantially as described with reference to figure 2.
16. A golf ball comprising a tag according to any preceding claim.
17. A golf ball according to claim 16, comprising 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.