IES84590Y1

IES84590Y1 - Method and apparatus for measuring a golf stroke

Info

Publication number: IES84590Y1
Application number: IE2004/0818A
Authority: IE
Inventors: Francis Mooney Brian
Original assignee: Francis Mooney Brian
Filing date: 2004-12-06
Publication date: 2007-05-30

Abstract

ABSTRACT A method of an apparatus for tracking or measuring the movement characteristics of an object uses the detection of changes in beams. A set of beams F1 — B1, F2 — B2, F3 - B3 is disposed in the movement path of the object; at relative angles to each other; and at acute angles to the intended direction of the object. The number of changes in the beams or durations between changes in the beams are recorded. The relative times, durations or differences in relative times, at which different beams of the set are changed and are measured. The resulting measurements are associated with the relevant movement characteristics of the object.

Description

The present invention relates to a method and apparatus for measuring th!rEnovement 1 characteristics of an object by detection of the interruption of electromagnetic wave beams. The invention relates more specifically, but not exclusively, to a method and apparatus for measuring the movement characteristics of a substantially straight edge or flat surface, such as the leading edge or face of a golf club. The invention also relates more specifically, but not exclusively, to a method and apparatus for measuring the movement characteristics of an object struck by a substantially straight edge or flat surface, such as a golf ball, which has been struck by a golf club face.

The prior art has produced various devices which claim to measure certain movement characteristics of golf club faces and golf balls by detection of the interruption of electromagnetic wave beams.

Wilson, US 4,150,825; Takase et al., US 4,542,906; Arnold et al., US 5,333,874; lijima et al., US 5,481,355 and Pao et al.. US 5,626,526, all disclose devices which are stated to measure certain movement characteristics of a golf ball passing through one or more substantially vertical, planar arrays of optical beams and sensors. positioned a relatively short distance downstream of the starting position of the ball.

Rusnak, US 4,254,956, discloses a device which is said to measure certain movement characteristics of the shadow of a golf club head passing over a mat comprising a horizontal planar array of optical sensors, the shadow being generated by a single overhead lamp which casts substantially vertical optical beams. The device also proposes means to determine the vertical height of the golf club.

White, US 4,630,829, discloses a device which is stated to measure the speed of a golf club head passing through two pairs of substantially horizontal, transverse optical beams.

Pao, US 6,302,802, discloses a device which is said to measure certain movement characteristics of a golf ball and golf club head passing through a single planar array of optical beams and sensors, positioned a relatively short distance downstream of the starting position of the ball. The planar array is oriented at an angle which is midway between horizontal and vertical. All measurements are taken following completion of IE 040818 impact and contact between the club and ball, when the club no longer retains the characteristics relevant to impact.

None of these prior art speciﬁcations discloses a device which can accurately measure the important movement characteristics of a golf club face or of a golf club face and ball.

The present invention seeks to overcome many of the deficiencies of the prior art.

The present invention provides a method and apparatus for measuring the movement characteristics of an object by detection of the interruption of electromagnetic wave beams. Where the object includes a substantially straight edge or ﬂat surface, the movement characteristics may include movement characteristics of the edge or surface, such as its angle and position relative to the direction of motion. The invention relates more particularly, but not exclusively, to a method and apparatus for measuring the movement characteristics of the leading edge or face of a golf club. The invention also relates more particularly, but not exclusively, to a method and apparatus for measuring the movement characteristics of a golf ball, which has been struck by a golf club face.

The present invention relates to an insight that the motion characteristics of an object moving in a plane can be determined by the interruption or reinstatement of beams in that plane, where the beams are set at different angles to each other.

An aspect of the invention relates to an appreciation that the relative direction and relative speed of an object moving in a plane can be determined by the durations, and differences in durations, between interruptions in two sets of parallel beams in that plane, where the sets are lying at different relative angles, provided certain knowledge is available regarding the shape of that part of the object which first interrupts the beams.

A further aspect of the invention relates to an appreciation that the relative angle and relative offset of a substantially straight edge moving in a plane can be determined by the durations, and differences in durations, between the interruptions of a plurality of beams in that plane, where at least three or four lie at different relative angles to each other, provided certain knowledge is available regarding the shape of that part of the object which ﬁrst interrupts the beams.

|E040818 Yet another aspect of the invention relates to an appreciation that the relative direction and relative speed of an object moving in a plane can be determined by the durations, and differences in durations, between interruptions and reinstatements of two beams in that plane, where the beams are lying at different relative angles, provided certain knowledge is available regarding the shape of that part of the object which ﬁrst interrupts and ﬁrst reinstates the beams.

Where applied to a golf swing, the first said aspect of the invention relates to an appreciation that the relative direction and relative speed of a moving golf ball, or a moving golf club face, projected onto a substantially horizontal plane, can be determined by the durations, and differences in durations, between interruptions in two sets of parallel beams in that plane, the sets lying at different relative angles.

The second said aspect of the invention relates to an appreciation that the relative angle and relative offset of a moving golf club face projected onto a substantially horizontal plane, can be determined by the durations, and differences in durations, between the interruptions of a plurality of beams in that plane, where at least three or four lie at different relative angles to each other.

The third said aspect of the invention relates to an appreciation that the relative direction and relative speed of a moving golf ball, projected onto a substantially horizontal plane, can be determined by the durations, and differences in durations. between interruptions and reinstatements of two beams in that plane, the beams lying at different relative angles.

The invention will now be described more particularly with reference to the accompanying drawings in Figure 1 to Figure 10 (b), which show, by way of example only, an embodiment of the invention which is suitable as a device which measures the movement characteristics of a golf club face and a golf ball which has been struck by a golf club face.

In the drawings: Figure 1 shows a diagrammatic plan view of the detection region of an apparatus, suitable for measuring the motion characteristics of a golf club face and golf ball, including an emitter means and receiver means. The figure also shows a golf ball placed in position, |E040818 prior to being struck by the club, and shows an imaginary straight line representing the intended direction of motion of the ball from right to left. The emitter means, shown on the lower region of the figure, emits ﬁve pairs of beams which are detected by the receiver means, shown on the upper region of the figure. Each pair of beams comprises two beams at reversed angles with their intersections lying on the line of the intended direction of movement of the ball.

Three pairs of beams are positioned on the club incoming side of the ball, to its right, and two are positioned on the outgoing side, to its left. Two of the pairs of beams on the incoming side have beams which are parallel to each other and have intersections which are spaced apart. The third pair of beams is set at different reverse angles, but has its intersection coincident with one of the other pairs. Both pairs of beams on the outgoing side have beams which are parallel to each other and have intersections which are spaced apart.

Figure 2 shows a magnified view of the central incoming region of the apparatus illustrated in Figure 1, but with the third pair of beams omitted for clarity. It also shows four representations of the club face approaching the ball, each representation showing the club face position as it first interrupts each of the four beams. Each representation relates to the substantially flat surface or leading edge of the club face, as projected onto the horizontal plane. The ﬁgure also shows various construction lines and angles used in the determination of club face direction and club face speed.

Figure 3 shows a similar view to Figure 2, except than in this instance the omitted pair of beams is that which has its intersection spaced apart from the others. it also shows various construction lines and angles used in the determination of club face angle.

Figure 4 shows a similar view to Figure 2. but includes an imaginary straight line passing through the midpoints of the representations of the club face. It also shows various construction lines and angles used in the determination of the position of the club face relative to the impact point on the ball.

Figure 5 shows a magniﬁed view of the central outgoing region of the apparatus illustrated in Figure 1. It also shows four additional representations of the ball after an impact which hits the ball in a direction to the right of the intended direction. Each representation shows IE 040819 the ball position as it ﬁrst interrupts each of the four beams. The figure also shows various construction lines and angles used in the determination of ball movement direction and ball speed.

Figure 6 shows a magniﬁed view of the central outgoing region of the apparatus illustrated in Figure 1, but in this instance with just one pair of intersecting beams. it also shows four additional representations of the ball after an impact which hits the ball in a direction to the right of the intended direction. similar to that shown in Figure 5. Each representation shows the ball position as it ﬁrst interrupts and ﬁrst reinstates each of the two beams. The figure also shows various construction lines and angles used in the determination of ball movement direction and ball speed.

Figure 7 shows a similar view to Figure 1. but with greater details shown of the emitter means and receiver means. The elements of a parallel light beam within the emitter means are depicted by dashed lines.

Figure 8 shows a diagrammatic plan view of the apparatus, shown in Figure 1, but on a smaller scale. The figure includes the playing surface and player standing surface.

Figure 9 (a) shows the lower right hand corner of the apparatus, shown in Figure 7, on a larger scale. The view includes a portion of the emitter means and beams.

Figure 9 (b) shows an end view, looking from left to right, of the portion of the apparatus shown in Figure 9 (a). The view includes a portion of the emitter means and beams.

Figure 10 (a) shows the upper right hand corner of the apparatus. shown in Figure 7, on a larger scale. The view includes a portion of the receiver means and beams.

Figure 10 (b) shows an end view, looking from left to right, of the portion of the apparatus shown in Figure 10 (a). The view includes a portion of the receiver means and beams.

The elements of the illustrated beam are depicted as dashed lines.

The following is an index of the reference numerals used in the drawings: IE 040813 Apparatus Emitter means Receiver means Ball in starting position Line showing intended direction of flight Beam Beam intersection Representation of a moving club face .<°9°.‘*‘!3"9".‘>.°°!°.-* Representation of a moving ball . Emitter light source _|. 3 —\ —L . Emitter reflecting means _L K) . Emitter screening means _x CO . Receiver sensing means . Receiver focusing means _x U1 . Receiver screening means _L C) . Playing surface _x \l . Player standing surface MEASUREMENT OF CLUB FACE MOVEMENT Referring to Figures 1 to 4, the arrangement comprises three pairs of beams, F1-B1, F2- B2 and F3-B3. Each pair comprises two intersecting beams, which substantially lie in the horizontal plane. The beams are positioned relative to the ball such that the club face interrupts them prior to striking it.

The intersections of each pair of beams lie on a straight line which passes through the centre of the ball and lies in the horizontal plane. it is also coincident with the projection of the intended flight direction of the ball on the horizontal plane, which will henceforth be referred to as the “intended direction”.

Beams F1 and F2 lie at equal angles, 8, to the intended direction. Beams B1 and B2 also lie at equal angles, S, to the intended direction, but in opposite directions of rotation to those of F1 and F2. For convenience throughout this specification, angles to the intended direction which are of equal magnitude, but lie in opposite directions of rotation, will be referred to as being “reverse" angles to each other. Beams F3 and B3 similarly lie at reverse angles to each other, in this instance the angle being T to the intended direction of flight. Angles S and T are shown at 75° and 65°, respectively, in the figures.

The intersections of beam pairs F2-B2 and F3-B3 are coincident. They are spaced a small distance from the edge of the ball, sufficient to ensure that the beams are clear of the ball surface. In the figure, this distance is shown as 5 mm. The intersection of beam pair F1- F2 is spaced a distance away from the joint intersection of beam pairs F2-B2 and F3-B3.

In the figure. this distance is shown as 50 mm.

Each of the ﬁgures shows the same example of club swing movement, which is deliberately made imperfect in respect of club movement direction, club face angle and club face position relative to the impact point on the ball. Club movement direction is shown at an angle -U, relative to the intended direction. Club face angle is shown at an angle +Z, relative to the club face direction and therefore ~(U—Z) to the intended direction.

The club face position at impact is shown with the impact occurring off-centre closer to the toe of the club.

The apparatus is operable to determine the club movement direction, club speed, club face angle and club face position at impact by calculation methods which commence with an accurate recording of the times at which the six incoming beams are ﬁrst interrupted.

For convenience, the characteristic related to club face position at impact will be referred to as club face "offset” throughout this specification.

CLUB FACE DIRECTION The determination of club movement direction relies on a recognition that the distance travelled by any point on the club face between the two parallel beams F1 and F2, or the two parallel beams B1 and B2, will varies with the relative angle of direction to the beam, becoming shorter as the club direction of motion becomes more closely aligned with the perpendicular to the beam and becoming longer as it becomes less closely aligned.

Accordingly, since the two sets of parallel beams lie at different angles, the ratio of the distance travelled between them provides sufficient information to give a direct indication of the relative angle of direction of club motion.

IE 040813 Referring again to Figure 2, this shows a club face travelling in a direction parallel to lines DA and HE, at an angle of magnitude U to the intended direction. The club face is represented by DH, CG, BF and AE where it first encounters beams F2, F1, B1 and B2 respectively.

All references to club faces refer to its substantially straight leading edge, as projected in the horizontal plane. For example, in the case of line DH, point D represents the corner of the flat leading edge of the club closest to its toe or distal end. Point H represents the corner closest to its heel or shaft end.

The club face is assumed to remain at a substantially constant speed and at a substantially constant angle to its direction of motion as it interrupts the four beams.

Therefore the two time intervals which are recorded between F1 and F2, and between Btand B2 being broken will be in proportion to the distances AC and FH, respectively.

Therefore, measurement of these two time intervals will provide the ratio AC / FH.

The figure also shows a perpendicular line CJ drawn from point C onto the line representing beam F2 and a perpendicular line HK drawn from point H onto the line representing beam B2.

Triangle CAJ is a right angled triangle, and angle CAJ = S + U.

Therefore, CJ = AC x sin (S+U).

Triangle KFH is a right angled triangle, and angle KFH = S — U.

Therefore, HK = FH x sin (S-U).

Since the two sets of parallel beams are equally spaced apart, CJ = HK.

Therefore, FH x sin (S-U) = AC x sin (S+U). and AC / FH = sin (S-U) I sin (S+U).

Since S and the ratio AC / FH are known, it is therefore possible to calculate the angle of club movement direction, U, relative to the intended direction.

CLUB SPEED "E 040818 The speed of the club face, as projected in the horizontal plane, can be determined when the angle of club movement, U, is determined, since this allows distances to be calculated between two recorded instances of the beams being interrupted. The parallel sets of beams provide the framework for this distance calculation.

Referring again to Figure 2, it can be seen that where the toe end corner of the club face interrupts beams F1 and F2 at C and A, respectively, the distance travelled is AC. Since the distance CJ between parallel beams is a known characteristic of the apparatus, AC can therefore be calculated, since AC = CJ / sin (S+U). Referring to the time duration between the recorded interruptions of F1 and F2 as TF, the speed is therefore given by Speed = (distance)/(time) = TF / [CJ / sin (S+U)].

The speed can also be determined where the heel end of the club interrupts beams B1 and B2. Since HK = CJ, where the time duration between the recorded interruptions of B1 and B2 is referred to as TF, then similarly Speed = (distance)/(time) = TB / [CJ / sin (S+U)].

Where club motion is in a straight line, both values for speed should be the same and an average may be taken if the results differ slightly.

CLUB FACE ANGLE AND OFFSET A club face which is at an angle to the orthogonal to the intended direction will contact the beams in a different manner to one which is orthogonal to it. In general, for the arrangement shown in the figures, where the club face is increasingly “open” (i.e. where the club face is increasingly angled clockwise away from the orthogonal to the intended direction), the corner of the club face nearest the heel will contact the beams sooner than it would otherwise do and the corner nearest the toe will contact it later. Conversely, where the club face is increasingly “closed" (i.e. where the club face is increasingly angled clockwise away from the orthogonal to the intended direction), the corner of the club face nearest the heel will contact the beams later than it would otherwise do and the other corner will contact it sooner.

[E 0408 Also, an offset club face, i.e. a club face which is travelling such that the locus of its centre is offset from the intersection of the beams and the centre of the ball, will contact the beams in a different manner to one which is aligned to the intersection and the centre. In general, for the arrangement shown in the figures, with increased offset of the centre of the club face closer to the player, the corner of the club face nearest the heel of the club will contact the beams sooner than it would otherwise do and the corner nearest the toe of the club will contact it later. Conversely, with increased offset of the centre of the club face away from the player, the corner of the club face nearest the heel will contact the beams later than it would othen/vise do and the corner nearest the toe will contact it sooner.

The characteristics relating to the angle and offset of the club face each affect the relative sequences at which the corners of the clubface interrupt the beams. and the relationships are also affected by the ﬁxed angle between the beams and the intended direction. An aspect of the present invention relates to a realisation that these relationships are affected differently for changes in angle and changes in offset and that it is possible to use these differences to distinguish angle and offset where use is made of two sets of beams at different angles to the intended direction.

One important difference relates to the manner in which club face angle and club face offset affect the interruption of sets of beams which are at different angles and sets of beams which are at reverse angles, in each case relative to the intended direction. For example, where the shot is otherwise straight and even, an angled club face will cause F2 and B2 to switch at different times, and will also cause F3 and B3 to switch at different times, it will have a similar or identical effect on the relative switching between F2 and F3 as it will on the relative switching between B2 and B3. This is not the case for a club face which is offset. where the shot is otherwise straight and even. In this instance, the offset will similarly cause F2 and B2 to switch at different times, and will cause F3 and B3 to switch at different times, but it will have quite a different effect on the relative switching between F2 and F3 as it will on the relative switching between B2 and B3. The switching difference will be relatively greater between F2 and F3 if the club face is offset away from the player and will be relatively greater between B2 and B3 if the club face is offset closer to the player. A more complete understanding will be gained by the following trigonometric analysis.

IE 0408 CLUB FACE ANGLE Referring now to Figure 3, this shows a close up view of the arrangement with beam pair F1-B1 omitted for clarity. The figure shows a club face travelling in a direction parallel to lines GM and BF, at an angle U to the intended direction. The club face is represented by FL, EK, DJ and DH where it ﬁrst encounters beams B3, B2, F3 and F2, respectively.

The motion of the club face is the same as that shown in Figure 2 and the club face is again assumed to remain at a substantially constant speed and at a substantially constant angle to its direction of motion as it passes through the four beams. The club face is at an angle to a perpendicular to the direction of motion and is also at an angle to a perpendicular to the intended direction. The locus of motion of the centre of the club face is also offset from the intersection of the beams, A, and from the centre of the ball.

The system takes a time measurement as each beam is disrupted and from this determines the lengths KL, JK and HJ from knowledge of the club speed and the times taken to traverse those distances, as directly measured by sensors on the F2, B2, F3 and B3 beams. This also determines the lengths of EF, DE and CD, which equal KL, JK and HJ, respectively.

The ﬁgure shows two further lines, BG and FM. BG passes through A and is perpendicular to BF and GM. FM commences from point F and is also perpendicular to BF and GM. The figure further deﬁnes angle GAH as angle AFB as “W”, angle BAE as angle EAF as “Y”, and angle LFM as Y is known, because Y = S —T, both of which are known.

Since GA lies at an angle U to the perpendicular to the intended direction, observation of angle GAN shows that X + S = 90° + U. Therefore, X is known, because 8 and U are known.

W is known because, ABF is a right angle triangle with (X + Y) + W = 90°, and X and Y are known. "$0408 V is also known, because the straight angle to the left of the F2 beam, about point A, is equal to 180° = V + X + 28. Therefore, V = [180° — X — 23] = [180° — (90° + U — S) — 28] = [90° — U — 8].

AB is found as follows. AE is first found by application of the standard trigonometric solution for the oblique sided triangle AEF, i.e. AE = EF x sinW / sinY. Therefore AE is known, since EF, W and Y are known. EF has been determined by measurement of the disruption of beams B3 and B2. Therefore, AB is found since AB = AE x cosX.

AG is found in a similar manner to AB, as follows. AH is found by application of the standard trigonometric solution for the oblique sided triangle AHJ, in which angle HJA = W and angle HAJ = Y. i.e. AH = HJ X sinW / sinY. Therefore AH is known, since HJ, W and Y are known. HJ has been determined by measurement of the disruption of beams F2 and F3. Therefore, AG can be found since AG = AH x cosV, and V and AH are known.

The sides of triangle LMF can now be determined as follows. GM is known, since GM = BF, BF = BE + EF and EF is known and BE = AB x tanX. GH is known, since GH = AG x tanv, and AG and V are both known. LM is known, since LM = GM — (GH + HJ + JK + KL), and GM, GH, HJ, JK and KL are all known. FM is known, since FM = AB + AG, and AB and AG are known.

The angle of the club face relative to the orthogonal to the direction of movement of the club, Z, can now be determined from triangle LMF. Z is known, since tanZ = LM/FM and LM and FM are both known. The angle of the club face relative to the orthogonal to the intended direction is equal to (Z + U).

CLUB FACE OFFSET It can be appreciated from Figure 3 that point A is (AB-AG)/2 distant from the mid point of line BG. Therefore the offset of the locus of motion of the centre of the club face from the intersection of the F2-B2 and F3~B3 beams, A, is given by (AB-AG)/2, where the offset is measured at right angles to the direction of motion of the club. Where the club is not travelling in the same direction as the intended direction, this offset will not be the same as the offset from the centre of the ball. The offset from the centre of the ball can be IE 0408 determined by adding or subtracting, as appropriate, to the offset relative to the intersection, the additional offset component due to the ball travelling at an angle different to the intended direction. This is illustrated in Figure 4.

Referring now to Figure 4, this shows a swing which is identical to that shown in Figure 3, with the club face again represented by FL, EK, DJ and DH where it first encounters beams B3, B2, F3 and F2, respectively. For clarity, beams F2 and B2 are omitted from the figure. B is the centre of the ball and A is the intersection of beams F3, B3, F2 and B2.

Each of the club face positions shown in the ﬁgure has a mid point M. RG is the locus of these mid points. The club face mid point moves in a substantially straight line movement over the short distance approaching the ball. RG is at an angle U to the intended direction OG.

AP, the perpendicular line from point A onto line RG, is the offset distance from the locus of the midpoints to the intersection of the beams. it is equal to the value (AB—AG)/2 shown in Figure 3, as discussed earlier.

BN, the perpendicular from the ball centre onto line GR, is the offset distance from the locus of the midpoints to the centre of the ball. It can be determined as follows. BN = AP — AQ, since BN = PQ. AQ = AB x sinU. AB and U are known, AB being the fixed distance between the ball oentre and the intersection of the beams.

The offset BN is a signiﬁcant characteristic of the golf swing since it is a direct measure of the “sweetness” of the swing, or how close mid point of the club face is to the point of impact, since the mid point is commonly understood to coincide with the centre of inertia of the club. Where a different point on the club face is known to coincide with the centre of inertia, the calculation should be adjusted as appropriate.

MEASURMENT OF BALL MOVEMENT Referring to Figure 1 and Figure 5, the arrangement comprises two pairs of beams, F4-B4 and F6-B6. Each pair comprises two intersecting beams, which substantially lie in the horizontal plane.

The intersections of both pairs of beams lie on a straight line in the intended direction, and which passes through the centre of the ball and lies in the horizontal plane.

Beams F4 and F6 lie at equal angles, 8, to the intended direction. Beams B4 and B6 lie at equal reverse angles to those of F4 and F6. Angle S is shown at 75° in the figures.

The intersection of beam pairs F4-B4 is spaced a small distance from point where the ball separates from the club face after impact. In the ﬁgure, this distance is shown as 15 mm.

The intersection of beam pair F6-B6 is spaced 60 mm away from the intersection of beam pairs F4-B4.

Ball movement direction is shown at an angle -U, relative to the intended direction.

The apparatus is operable to determine the ball movement direction and ball speed, after the ball has separated from the club face and commenced free flight, by calculation methods which commence with an accurate recording of the times at which the four beams are first interrupted.

BALL DIRECTION Similar to the determination of club movement direction, described earlier, the determination of ball movement direction relies on a recognition that the distance travelled by any point on the ball between the two parallel beams F4 and F6, or the two parallel beams B4 and B6, will varies with the relative angle of direction to the beam, becoming shorter as the club direction of motion becomes more closely aligned with the perpendicular to the beam and becoming longer as it becomes less closely aligned.

Accordingly, since the two sets of parallel beams lie at different angles, the ratio of the distance travelled between them provides suflicient information to give a direct indication of the relative angle of direction of club motion.

Referring again to Figure 5, this shows a ball, with its centre travelling along line AG, which lies at an angle of magnitude U to the intended direction. The ball is shown with its centre at positions D, E, F and G where it ﬁrst interrupts beams F4, B4, F6 and B6, respectively. The initial point of interruption is where the beam lies as a tangent to the IE 0408 leading surface of the ball and the point of first contact can be found as the perpendicular from the centre of the ball to the beam. These first points of contact are at positions H, l, J and K on beams F4, B4, F6 and B6, respectively.

The ball may be reasonably assumed to remain at a constant speed and at a constant angle to its direction of motion as it interrupts the four beams. Therefore the two time intervals which are recorded between F4 and F6, and between B4 and B6 being broken will be in proportion to the distances HJ and IK, respectively. Therefore, measurement of these two time intervals will provide the ratio HJ / IK. These distances also relate to the relative positions of the ball, since HJ = DF and IK = EG.

The figure also shows lines HN and IM, both parallel to the intended direction, where N lies on beam F6 and M lies on beam B6.

It can be seen from the ﬁgure that lK > HJ and that the ball travels to the right. It will immediately be appreciated that IK = HJ where the ball travels straight and that IK < HJ where the ball travels to the left. It will also be appreciated that there is a unique value for the ratio HJ / IK for each direction of the ball and that knowledge of this value, from measurement of the appropriate beam interruption time intervals, allows the direction of the ball to be determined.

The following trigonometric analysis provides a direct relationship between angle U and the ratio IK/HJ.

In triangle IKM, using the standard solution for an oblique triangle, IK/IM = sin(lMK)/ sin(lKM). Length IM and angle (IMK) are known values. Also, angle(lMK) + ang|e(lKM) + ang|e(KlM) = 180°, therefore ang|e(lKM) = ([a known value] — U).

Therefore. IK = (a known value) / sin ([a known value] — U).

Similarly, in triangle HJN, HJ/HN = sin(HNJ) / sin(lKM). Length HN and angle (HNJ) are known values. Also, as before, ang|e(lKM) = ([a known value] — U). Therefore, HJ = (a known value) / sin ([a known value] — U).

Combining these, IK/HJ = (a known value) x sin([a known value] — U) I sin([a known value] - u).

IE 0408 BALL SPEED The speed of the ball, as projected in the horizontal plane, can be determined when the angle of ball movement, U, is determined, since this allows distances to be calculated between two recorded instances of the beams being interrupted. The parallel sets of beams provide the framework for this distance calculation, since the distance between them is a known characteristic of the apparatus.

Referring again to Figure 5, perpendiculars HP and IQ are constructed from points H and l, respectively, onto beams F6 and B6, respectively. Angles HJP and IKQ are denominated as “V” and “W”, respectively.

It can be seen from the figure that where the ball interrupts beams F4 and F6 at H and J, respectively, the distance travelled is HJ. Since the distance HP between parallel beams is a known characteristic of the apparatus, HJ can therefore be calculated, since HJ = HP I sinV, and V is a known value. In triangle HJN, V + U + S = 180° and U and S are both known values.

Similarly, it can be seen from the figure that where the ball interrupts beams B4 and B6 at l and K, respectively, the distance travelled is IK. Since the distance IQ between parallel beams is a known characteristic of the apparatus, lK can therefore be calculated, since IK = lQ / sinW, and W is a known value. Angle IMK = 180° — S. Therefore, in triangle IKM, W + U + [180°-S] = 180'’, i.e. W = S — U, and U and S are both known values.

Both values for speed should be the same and an average may be taken if the results differ slightly.

ALTERNATIVE METHODS FOR CALCULATING BALL DIRECTION AND SPEED.

Figure 6 refers to an alternative method for measuring ball direction and speed. In this instance, the system records the interruption and reinstatement of the beams and uses just one set of beams, F6-B6.

Similar to the method, described earlier, the alternative determination of ball movement direction again relies on a recognition that the distance travelled will vary with the relative angle of direction to the beam, becoming shorter as the ball direction of motion becomes more closely aligned with the perpendicular to the beam and becoming longer as it ‘E 0408 becomes less closely aligned. The ratio of the distance travelled through the two beams at different angles will provide sufﬁcient information to give a direct indication of the relative angle of direction of the ball.

Referring now to Figure 6, this shows a ball, with its centre travelling along line AF, which lies at an angle of magnitude U to the intended direction. The ball is shown with its centre at positions C, D, E and F where it ﬁrst interrupts F6, interrupts B6, reinstates F6 and reinstates B6, respectively. The initial point of interruption or reinstatement is where the beam lies as a tangent to the leading or trailing surface of the ball and the point of ﬁrst contact can be found as the perpendicular from the centre of the ball to the beam. These first points of contact are at positions G, H, I and J on beams F6, B6, F6 and B6, respectively. The locus of the ball centre commences at A and crosses beams F6 and B6 at N and M, respectively. The locus of the ball centre also lies at angles Y and W to beams F6 and B6, respectively.

The ball may be reasonably assumed to remain at a constant speed and at a constant angle to its direction of motion as it interrupts and reinstates the two beams.

The following insight is an aspect of the invention. The angle of direction and the speed of the ball are capable of being calculated solely from knowledge of the periods between interruption and reinstatement of the two beams. Where the periods are equal, the ball is travelling along the intended direction. Where the period is shorter across the F6 beam, the direction is to the right. Where the period is shorter across the B6 beam, the direction is to the left. The greater the difference in periods, the greater is the deviation from the intended direction.

The following trigonometric analysis provides a direct relationship between angle U and the ratio EN / DK. SinY = EH / EN. SinW = DI / DK. EH and DI are both known values, being the radius of the ball. The ratio EN / DK is also a known value. since it is equal to the ratio of the time intervals between beam F6 being interrupted and reinstated and beam B6 being interrupted and reinstated, since ball speed is constant and EN and DK each correspond to half the distance travelled in each time interval. Therefore, sinY / sinW = known value. From observation of triangle ABK, it can be seen thatW + U + (180° - S) = 180°, i.e. W = S — U. From observation of triangle CGN, it can be seen that Y = 180° — S — lE04os1a U. Therefore, sin(180° — S - U) / sin(S — U) = known value. Since 8 is also a known value, angle U may be solved.

Once the direction of motion is known, it is possible to determine the speed, since the ball diameter is known. Referring again to Figure 6, it can be seen that the distance travelled by the ball, as it interrupts and then reinstates beam B6, is given by line DF. This distance exceeds the ball diameter by length LM. LM is found as follows. In triangle FJK, sinW = FJ / (FM + KM). Therefore, KM is a known value since FJ and FM are known values, each being equal to the radius of the ball. FJK and DIK are similar triangles, because FJ = DI, therefore KM = KL. Therefore the value for LM is known. Therefore the value for DF is known. The speed can then be calculated by dividing this distance by the time interval recorded where beam B6 was interrupted and then reinstated.

A very similar exercise will yield the value for CE. The speed can similarly be calculated by dividing this distance by the time interval recorded where beam F6 was interrupted and then reinstated. Both values for speed should be the same and an average may be taken if the results differ slightly.

The following comparisons made be made between the two ball movement measurement methods. The earlier described interrupt-only method may provide the following potential advantages. Recording of time interval will not be distorted by variables which equally affect both signals since time intervals are determined between like interrupt signals. The distance over which the interval is measured is not conﬁned to a dimension related to the diameter of the golf ball. The measurements are not dependant on prior knowledge of the golf ball diameter. The later described interrupt and reinstate method may provide the following potential advantages. It requires only one set of beams. It can also detect the trailing club face since the signal is always reinstated immediately after the ball has passed through it.

A second alternative method utilises the starting position of the ball as one of the reference points for the measurement of ball movement direction and ball speed. Similar to the first alternative method, it requires only one set of beams, but in this instance it does not have the disadvantage of being confined to a dimension related to the diameter of the golf ball. However, it has several relative disadvantages. These include a dependency on the accuracy or consistency of the ball starting position. They also include IE 0408 the necessity to measure or estimate the time of commencement of ball take-off from the starting position. They further include the necessity to accommodate the early period of movement of the ball when it is in contact with the club face, when the speed is constantly changing and the movement is not necessarily in a straight line.

POSITION OF THE BALL TRACKING BEAMS.

An important consideration, where the object being measured is being trailed by a second object, is that the beam interruption or reinstatement is not affected by the trailing object.

For example, where a golf ball is struck by a golf club, the necessary beam interruption or reinstatement signals measuring the ball must be completed before the club face interrupts the beams.

This will usually present no problem where the ball measurement signals are solely interruption signals, because the leading face of the ball is at least one ball diameter ahead of the contact region of the trailing club face and this is sufﬁcient to ensure that the ball will interrupt all beams ahead of the club face.

However, this condition does not apply where the beams are required to be reinstated before being broken by the trailing club face. In this instance, a gap must be provided between the beams and the starting position of the ball. The minimum size of this gap can be estimated from consideration of the mechanics of a golf club hitting a golf ball. In a typical drive shot, the ball and club face remain in contact for about 11.5 mm. The club contacts the ball at about 30 m/s and gradually slows down to about 24 m/s during the contact period. The ball separates from the club face at about 52 m/s. Thus, after separation, the ball typically travels at slightly more than twice the speed of the club face.

In an idealised situation, where a perfect shot is taken with the club face central, square and travelling in the intended direction, and where the beam is set orthogonal to the intended direction, and where the ball speed is twice the club face speed, the beam could be set just one ball diameter ahead of the ball at the point where the ball and club face separate. Where the ball diameter is 42 mm, the beam would be reinstated with a gap of 21 mm still remaining between it and the trailing club face. lE04oe However, in a real situation, accommodation must be made for the club face not being, central and square and for the beams not being orthogonal to the intended direction.

Accommodation must also be made for a poorly hit shot where ball speed could fall well short of being twice club face speed. Overall, a gap of about 70-100 mm will usually suffice between the beams and the leading face of the ball prior to impact.

VERTICAL HEIGHT CONSIDERATIONS.

Up to this point, consideration has only been given to the determination of movement in the horizontal plane. However, both the club and ball have important components of movement in the vertical plane which must be accommodated by the method and apparatus.

One aspect of vertical movement relates to the measurement of movement in the horizontal plane. Where the club face is being tracked, it will usually be desired to detect a consistent straight edge, such as the most fonivard leading straight edge, close to the lower edge of the club face. Where the ball is being tracked, it will usually be required to detect the full diameter in the horizontal plane through the centre of the ball, and not a lesser diameter above or below this level. The preferred method for achieving this type of detection is to use a band-type beam, which has minimal horizontal thickness, but has sufficient vertical height such that the range of possible positions of the object to be detected will interrupt some point on the band. in general, the system is operable to detect a change in the status of the banded beam, typically in the form of a partial interruption or a reinstatement to a status existing prior to an interruption.

Another aspect of vertical movement relates to the measurement of movement in the vertical plane. In this instance. the objective is to determine the vertical height component itself. Once again a banded-type beam may be used. However, in this instance the determination is concerned with measuring the height or degree to which the beam is interrupted. Typically it is detecting the lowest or highest point on the object, whereas the previous type is typically concerned with detecting the leading or trailing point on the object.

IE 0408 The two aspects of vertical movement may be detected by separate beams or by beams arranged to carry out both functions.

Beams which carry out both functions have the advantage of reducing the number of beams, and thereby reduce the number of components with the potential to reduce cost and problems.

Where separate beams are dedicated to the two functions, these have the potential to give the following relative advantages. The vertical beams can be a single beam orthogonal to the intended direction, rather than follow the angled pairs used for horizontal measurement. The vertical beams can also be ranged to detect the bottom or top of the ball, and the horizontal beams can be ranged to detect the centre leading or trailing edges of the ball, thus reducing the required vertical range for each. The horizontal beams can be arranged as simple yes-no detectors, with particular attention given to the accuracy of the yes-no switch. Under certain circumstances, vertical beams may be used where the same beam measures the top of low lofted balls and the bottom of high lofted balls.

A potential problem arises with band-type beams detecting vertical movement in a golf shot. This relates to the relatively steep loft of certain golf shots and to a lesser extent the steep downward swing of certain club movements. Where a simple band-type beam is used, a very high band is required unless the band is positioned very close to the starting position of the ball. However, several potential disadvantages arise from positioning the band close to the starting position. including compromise of accuracy of horizontal movement and prevention of the use of beam reinstatement signals for horizontal movement for ball detection, due to interruption by the trailing club face.

In a preferred embodiment of the present invention, at least one band-type beam is split into a plurality of bands, or is inclined at an angle to the vertical, such that movement in a horizontal plane at a relatively lower loft is detected further from the initial ball position than movement in a horizontal plane at a relatively higher loft.

This provides several potential advantages. including the following. It may increase the horizontal distance between the beam and the initial ball position for low lofted shots, such as drive shots, thereby increasing accuracy of movement detection in the horizontal plane.

This type of accuracy is of particular importance for low lofted shots. A second advantage is that it allows detection of highly lofted shots without requiring overly large band-type IE 0408 beams. A third potential advantage is that it reduces the maximum vertical height of the apparatus emitting and receiving the beams, thereby making it less prone to damage from errant golf swings and less visually distracting to the player.

For example, where a golf ball is detected over a loft range of 0—45° to the horizontal. one set of band-type beams, positioned relatively far from the initial ball position, detects all shots with a loft up to 20°. A second band-type beam is positioned closer to the initial ball position and detects all shots with a loft between 15° and 45°. The ﬁrst set is positioned 90 mm from the initial ball position and the 0°-20° loft corresponds to a vertical height range of zero to (90 x tan 20°), i.e. 0 mm to 32.76 mm above the level of the centre of the initial ball position. The second set is positioned 40 mm from the initial ball position and the 15° to 45° loft corresponds to a vertical height range of (40 x tan 15°) to (40 x tan 45°), i.e. .72 mm to 40.00 mm above the level of the centre of the initial ball position. A separate detection means detects the loft of the shot and determines whether the readings are taken from the first or second set of band-type beams.

NEURAL MEANS The mathematical models, which have been discussed, treat the club face as a fixed width, straight line surface with sharply deﬁned ends. In reality, the club face may not be exactly flat and the edges will not be sharply defined. Also, although the mathematical models automatically deal with all speciﬁc club widths. in reality, the effective width of the flat club face may also vary slightly with inclination of the club face.

These variations from the simple mathematical model may be dealt with in various ways.

One of these is to use more reﬁned mathematical models to accommodate the variations.

Another is to use an artiﬁcial neural-type intelligence means, which has been previously trained with information relating a wide range of beam signals to resulting motion characteristics of the club face and ball. By artiﬁcial neural-type intelligence means, henceforth referred to as neural means, is meant, determination or problem solving means, which operates in a manner which has similarities to human determination or problem solving. In particular, this type of determination of problem solving relates to previously learned experience from which a solution can be determined or interpolated when a new problem or situation arises.

|E0408 Where a neural means is used, it will usually be advantageous to pre-process some or all of the primary beam signals before presenting them to the neural means and weigh their relative importance to particular types of outputs. This pre-processing stage may be carried out by conventional electronic processing methods and devices.

For example, on the incoming beams measuring the club face, club direction and club speed outputs in the horizontal plane are weighted closely to pre-processed signals related to durations, and differences in durations, between interruptions in sets of parallel beams relevant to the club face. Club face angle and offset in the horizontal plane are weighted closely to pre-processed signals related to differences in durations between the interruption of relevant angled beams and beams at reverse angles to them of equal magnitude, for beam sets which are at different relative angles to each other. Club face angle and offset are also weighted closely to the determined values of club direction and speed. Ball direction and ball speed outputs in the horizontal plane are weighted closely to pre-processed signals related to durations, and differences in durations, between interruptions in sets of parallel beams relevant to the ball. Where reinstatement signals are also used, the outputs are closely weighted to pre-processed signals related to durations and differences in durations between interruptions and reinstatements of individual beams relevant to the ball.

APPARATUS.

A schematic depiction of an apparatus suitable for determining the movement of a club face and ball in a golf shot is shown in Figure 7 and Figure 8. The apparatus comprises a playing surface and the ball is positioned directly on the surface, or on a support tee on the surface, prior to the shot being taken. The playing surface may comprise a durable artificial turf or polymer mat. Optionally, the intended direction may be marked on the playing surface.

A bank of emitters is positioned along one side of the playing surface and a bank of receivers is positioned along the other side. These are laterally positioned sufficiently far from the paths of the club and ball to avoid being struck by any normal shot and also to IE 0408 minimise visual obtrusiveness. The vertical height is also minimised to avoid being struck and to minimise visual obtrusiveness.

The emitters and receivers may be supported by a common frame below the level of the playing surface to ensure that correct alignment is maintained between them.

The player stands on a mat or platform to equalise his or her standing position with that of the playing surface.

In the device shown in Figure 8, the emitters are mounted on the player side of the playing surface and the receivers are mounted on the other side. Each is positioned about 250 mm from the centre of the intended paths of the club and ball. Where desired, these values may be signiﬁcantly altered and the emitters and receivers positions may be interchanged.

The emitters and receivers are also covered by robust protective guards, which are omitted in the figures. These guards are of low profile to minimise visual obtrusiveness.

They have ramped ends and smooth outer surfaces to facilitate deﬂection of accidental wild shots.

The emitters comprise a source of electromagnetic radiation and a means to emit the radiation as substantially parallel horizontal rays, with a narrow vertical band profile.

Typically, the radiation will comprise visible light and the source will comprise one or more light emitting diodes (LEDs) or lasers. LEDs frequently have advantages of low cost and robustness. Lasers frequently have advantages of providing a very coherent light source with minimal diffraction giving rise to sharp edges which can be more accurately detected.

Optical lenses are used to arrange the rays into a parallel beam of the desired height and width. The required proﬁle may also be assisted by the use of collimating or shielding slots, adjacent the emitter face, which block rays which deviate from the required parallel profile.

The width of the band is minimised, within the technical constraints, to increase the accuracy of detection. A small amount of divergence is allowed as the beam crosses to lEo4os1e the receiver, in order that a small overlap occurs around the receiver entry. This overlap accommodates aiming tolerance errors. without reducing overall potential accuracy.

Where there is a danger that emitted rays may stray into incorrect receivers adjacent the intended target receivers, the emitters and receivers may be provided with matched pulsed signals, with all other signals being ignored. This may also be used to overcome interference problems with ambient light.

The horizontal component movement receivers typically comprise an entry shielding means, a focusing means, a detection means and a comparator means. The face of the receiver comprises a slotted shield which allows a narrow band of light to enter the receiver. The focusing means directs this narrow band of light into a concentrated more evenly shaped profile signal. The concentrated signal is directed to a detection means, such as a photodiode, which is operable to convert this to an electronic signal which is in some way proportional to the intensity of the light falling on it. The detection means should be of the type which is capable of giving a very fast response. The comparator means, comprises electronic components and circuits, and is operable to compare the level of this signal to the steady state background signal which is normally obtained. An interruption of the beam is flagged when the signal varies by some small prearranged amount from the background signal. In the case of beams where reinstatement signals are also registered, a reinstatement signal is flagged when the signal returns to the level of the background signal.

The light signal may be directly transferred from the focusing means to the detection means or it may optionally be transferred by way of a flexible optical ﬁbre. Where it is transferred by optical fibre, this can advantageously isolate the exposed optical portion of the receiver from the more sensitive electronic detector and comparator means.

Vertical component movement receivers may take various formats, one being very similar to the horizontal component movement receivers, described earlier, but with the following difference. The comparator means is operable to detect the minimum or maximum signal intensity levels occurring during the signal changes which occur as a club or ball pass through the beam, and to determine this as a proportion of the background steady state signal intensity level. This indicates the proportion of the beam that was obscured which allows the vertical height of the relevant edge of the ball or club to be determined.

IEO408l8 in an alternative format, the receiver means comprises a plurality of detector means, each detecting different levels of the received beam. The detector means may either be operable to perform as discrete signalling devices, flagging a set change from the background signal intensity, or they may be operable to determine the signal intensity as a proportion of the background steady state signal intensity level.

In a further alternative format, the face of the receiver may comprise a line of spaced apart optical ﬁbre ends, with each fibre routed to an individual detector which determine whether the signal is present or blocked, or with groups of adjacent ﬁbres collectively routed to individual detectors, each of which determines the signal intensity as a proportion of the background steady state signal intensity level.

In a preferred embodiment of the invention, the focusing means, and also possibly the shielding means, of the bank of emitters and bank of receivers, each comprise a single polymer moulding, or small number of polymer mouldings. This has the advantages of reducing the number and cost of components. It also reduces the cost of assembly and assists in ensuring that the component elements are in correct alignment. Typically, the moulding comprises a high precision plastic injection moulding, with integral moulded reflecting facets directing light as required.

Figures 9 (a) and 9 (b) show a schematic plan view and schematic end view of a portion of the emitter bank shown in Figure 7.

A light source is passed through an arrangement of one or more lenses and screens to obtain a beam of parallel rays of an approximate broad rectangular proﬁle. This broad beam is directed towards the polymer moulding, in a direction parallel to the intended direction of ball flight. The moulding comprises a series of appropriately shaped, staggered and angled vertical internal reflecting surfaces, which divide the broad beam into a plurality of narrow vertical bands, directed at the appropriate angles towards the target receiver openings. The reflecting surface may lie at an angle such that an orthogonal to its surface lies midway between the light source parallel beam and the reflected beam.

IE 0408 The outward face of the emitter bank is provided with a screening means which trims or collimates the emerging proﬁles of the banded beams. This screening means may comprise, for example, a precision printed pattern on the face of the emitter bank, with clear spaces left where the beam emerges, or it may comprise a separate screen component position in front of the face of the emitter bank or it may comprises an integral raised or indented surface on the face of emitter bank moulding, with the perimeter of the surface reﬂecting or scattering unwanted edges of the beam.

The reflection may be achieved in various ways. In one example, the parallel beam travels outside the moulding and reflection directly occurs against external surfaces of the moulding. In another example, the parallel beam travels within a transparent moulding and reﬂection occurs against single internal surfaces of the moulding. In further examples, the moulding is provided with prism type ridges and the outgoing beams are produced by refraction or a combination of refraction and reﬂection. Where appropriate, reflecting surfaces may be metallised to improve their reﬂecting properties.

Figures 10 (a) and 10 (b) show a schematic plan view and schematic end view of a portion of the receiver bank shown in Figure 7.

The outward face of the receiver bank is provided with a screening means which trims or collimates the entering proﬁles of the banded beams. Similar to the emitter bank, this screening means may comprise, for example. a precision printed pattern on the face of the receiver bank, with clear spaces left where the beam enters, or it may comprise a separate screen component position in front of the face of the receiver bank or it may comprises an integral raised or indented surface on the face of receiver bank moulding, with the perimeter of the surface reflecting or scattering unwanted edges of the beam.

Each banded parallel beam enters the interior of the moulding and impinges against a focusing means which directs the parallel light into a concentrated region at its focal region. A detector means, such as a photodiode, is positioned at the focal region.

Optionally, the focal region is optically connected to the detector means using a flexible optic fibre with one cross sectional end of the fibre facing into the focal region.

The focusing means may comprise a vertical Fresnel type lens comprised of a moulded polymer material. For example, the vertical Fresnel type lens comprises a surface with an IE 0403 array of closely spaced parallel prisms, with the outer ones acting as catadioptric prisms and the more central ones acting as dioptric prisms. The same polymer moulding may advantageously comprise a plurality of focusing means and screening means and may also comprise a seating which precisely locates the detector means.

The apparatus also comprises a beam switching means which is operable to detect when a swing is about to take place and is operable to automatically switch the beams on and off as required. The purpose of this is to minimise energy use and generation of unwanted heat. The beam switching means may operate in various ways. For example, the standing platform may be provided with a sensing means which is operable to detect the presence or movement of a player. This may be used to trigger the light source to turn on. for a short appropriate period of time. Alternatively, the apparatus may be provided with a sensing means which is operable to detect the movement of the club when the player ‘addresses the ball prior to executing a swing. As before, this may be used to trigger the light source to turn on, for a short appropriate period of time. Normally, the complete swing will occur within about two seconds of the address, and a time period of five seconds will be sufﬁcient to accommodate the slowest swing.

It will of course, be understood that the invention is not limited to the speciﬁc details described herein, which are given by way of example only and that various modifications and alterations are possible within the scope of the invention.

MACLACHLAN 8. DONALDSON, Applicant's Agents, Merrion Square.

DUBLIN 2.

!E 040813 /10 B6 B4 B p4BF1F F1 Figure 1 |Eo4o313 /10 Figure 2 IE 040818 Figure 3 G B3 4/10 F3 IE 040818 B1 F1 r¢.~ WV / IE 040818 /10 I Z W (D L 3 .97 Ln. o\ 0 © O\ F >0 lE040818 'E 040813 7/10 ﬁgure 7 IE 040813 3/10 6 \ / 2/16 4 /I» ‘I 8/ \\ / 17 1/ K # Figure 8 IE 040818 9/10 \ [R B F1 \\\ u u ﬁgure 9 (Q) 6 18\\\\\\\\ 1f '///E FWgure 9 (b) \ 2 \ \ 11 11 11 (E 040813 / 14 \e ///\ F1 6 F3 Figure 10 (Q) Figure 10 (lo) The following replacement page 28 and revised set of Claims were ﬁled on "‘ December 20 ‘E 0408 array of closely spaced parallel prisms, with the outer ones acting as catadioptric prisms and the more central ones acting as dioptric prisms. The same polymer moulding may advantageously comprise a plurality of focusing means and screening means and may also comprise a seating which precisely locates the detector means.

The apparatus also comprises a beam switching means which is operable to detect when a swing is about to take place and is operable to automatically switch the beams on and off as required. The purpose of this is to minimise energy use and generation of unwanted heat. The beam switching means may operate in various ways. For example, the standing platform may be provided with a sensing means which is operable to detect the presence or movement of a player. This may be used to trigger the light source to turn on, for a short appropriate period of time. Alternatively, the apparatus may be provided with a sensing means which is operable to detect the movement of the club when the player ‘addresses’ the ball prior to executing a swing. As before, this may be used to trigger the light source to turn on, for a short appropriate period of time. Normally, the complete swing will occur within about two seconds of the address, and a time period of ﬁve seconds will be sufficient to accommodate the slowest swing.

It will of course, be understood that the invention is not limited to the specific details described herein, which are given by way of example only and that various modifications and alterations are possible within the scope of the invention as "defined in the appended claims.

IE 0408

Claims

CLAIMS:

1. A method of measuring the movement characteristics of an object by detection of changes in beams, characterised by providing a set of beams which comprises at least two beams disposed in the movement path of the object; at relative angles to each other; and at acute angles to the intended direction of the object; recording the number of changes in the beams or durations between changes in the beams; and measuring the relative times, durations or differences in relative times, at which different beams of the set are changed and associating the resulting measurements with the relevant movement characteristics of the object.

2. A method according to Claim 1, wherein at least one longitudinal component of each beam in the set, lies in a common plane.

3. A method according to Claim 2, wherein the common plane is substantially horizontal.

4. A method according to any one of the preceding claims, wherein one beam is disposed at an acute angle clockwise to the intended direction of the object and the other beam is disposed at an acute angle counter clockwise to the intended direction of the object.

5. A method according to Claim 4, wherein the magnitude of the acute angles is equal

6. A method according to Claim 5, wherein two beams intersect at a point along the line of the intended direction of the object.

7. A method according to any one of the preceding claims, wherein the object is an edge, or projected edge, which is orthogonal or near orthogonal to the intended direction of the object.

8. A method according to Claim 7, wherein the edge is the projected leading edge of the face of the object and is substantially a straight line or slightly curved line. 35 IE 0408

9. A method according to Claim 7 or Claim 8, wherein the beams are disposed at acute angles to the intended direction of the object, of magnitude greater than the angle subtended between the edge and the intended direction of the object. 9a. A method according to any one of Claims 7 to 9, wherein the angles of the beams, relative to the intended direction, exceed the maximum range of the angle of the edge, relative to the intended direction, over which measurement is made.

10. A method according to Claim 9, wherein one of the movement characteristics of the object is the direction of movement of an edge relative to the intended direction of the object; wherein the set of beams comprises at least two pairs of parallel beams, with one pair disposed at a relative angle to the other pair; and the resulting measurement being associated with a determination of the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair.

11. A method according to Claim 10, wherein the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair has a fixed relationship to the angle of club face direction and angles of the beams.

12. A method according to either Claim 10 or Claim 11, wherein a second of the movement characteristics is the speed of movement of the edge; wherein speed is determined as distance divided by time, with time determined by the duration between one end of the edge effecting successive changes on two parallel beams of one of the pairs of beams, and distance determined by application of the determined direction of movement to the distance between the parallel beams.

13. A method according to any one of Claims 10 to 12, wherein the intersections of the beams disposed at relative angles to each other both intersect at points along the line of the intended direction

14. A method according to Claim 9, wherein another of the movement characteristics is the angle of the edge relative to the intended direction of the object; E 0408 wherein the set of beams comprises one pair of beams disposed in one rotation at different acute angles to the intended direction of the object and a second pair of beams disposed in the opposite rotation at different acute angles to the intended direction of the object; wherein the measurement is associated with the angle of the edge being indicated closer to the angle of beams which are changed later and being indicated further from the angle of beams which are changed sooner; and an increased difference between relative changes between beams of opposite rotation indicating the movement characteristic to be predominantly angle rather than offset; and a reduced difference between relative changes between beams of the same rotation indicating the movement characteristic to be predominantly offset rather than angle;

15. A method according to Claim 9 , wherein another of the movement characteristics is the angle of the edge relative to the intended direction of the object; wherein the set of beams comprises two beams disposed in one rotation at different acute angles to the intended direction of the object and a third beam disposed in the opposite rotation at an acute angle to the intended direction of the object; where the measurement is associated with the angle of the edge being indicated closer to the angle of beams which are changed later and being indicated further from the angle of beams which are changed sooner; and an increased difference between relative changes between beams of opposite rotation indicating the movement characteristic to be predominantly angle rather than offset; and a reduced difference between relative changes between beams disposed in the same rotation, indicating the movement characteristic to be predominantly offset rather than angle.

16. A method according to Claim 9 , wherein another of the movement characteristics is the offset of the edge relative to the intended direction of the object; wherein the set of beams comprises one pair of beams disposed in one rotation at different acute angles to the intended direction of the object and a second pair of beams disposed in the opposite rotation at different acute angle clockwise to the intended direction of the object; lEo4oa wherein the measurement is associated with the offset of the edge being indicated closer to the region comprising the most forward beam which is changed sooner and being indicated further from the region comprising a beam which is changed later; and a reduced difference between relative changes between beams which are disposed in the same rotation, indicating the movement characteristic to be progressively offset rather than angle; and an increased difference between relative changes between beams disposed in the opposite rotation indicating the movement characteristic to be progressively angle rather than offset.

17. A method according to Claim 9 , wherein another of the movement characteristics is the offset of the edge relative to the intended direction; wherein the set of beams comprises two beams disposed in one rotation at different acute angles to the intended direction and a third beam disposed in the opposite rotation at an acute angle clockwise to the intended direction. where the measurement is associated with the offset of the edge being indicated closer to the region comprising the most fonivard beam which is changed sooner and being indicated further from the region comprising a beam which is changed later; and a reduced difference between relative changes between beams which are disposed in the same rotation, indicating the movement characteristic to be progressively offset rather than angle; and an increased difference between relative changes between beams disposed in the opposite rotation indicating the movement characteristic to be progressively angle rather than offset.

18. A method according to any one of Claims 14 to 17, wherein the intersections of the beams are coincident and lie at a point on the line of the intended direction.

19. A method according to any one of Claims 14 to 18, wherein the magnitudes of angles of the opposite rotation are equal.

20. A method according to Claim 6, wherein the object is of a regular shape which is substantially independent of orientation, including a sphere. circle or point. 35 |E0408

21. A method according to Claim 20, wherein another of the movement characteristics is the direction of movement of the object relative to the intended direction; wherein the set of beams comprises at least two pairs of parallel beams, with one pair disposed at a relative angle to the other pair; the measurement being associated with a determination of the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair.

22. A method according to Claim 21, wherein the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair has a fixed relationship to the angle of club face direction and angles of the beams.

23. A method according to Claim 21 or Claim 22 , wherein another of the movement characteristics is the speed of movement of the object; wherein speed is determined as distance divided by time, with time determined by the duration between the object effecting a changes on two parallel beams of one of the pairs of beams, and distance determined by application of the determined direction of movement to the distance between the parallel beams.

24. A method according to any one of Claims 21 to 23 , wherein the intersections of the beams disposed at relative angles to each other both intersect at points along the line of the intended direction

25. A method according to Claim 20, wherein another of the movement characteristic is the direction of movement of the object relative to the intended direction: wherein a change is recorded when the object first disrupts the beam and a change is recorded when the beam is reinstated when the object passes through it; the measurement being associated with a determination of the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam.

26. A method according to Claim 25, wherein the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam has a fixed relationship to the angle of club face direction and angles of the beams. 35 IE 0408

27. A method according to either Claim 25 or Claim 26, wherein another of the movement characteristic is the speed of movement of the object; wherein speed is determined as distance divided by time, with time determined by the duration between the object effecting disruption and reinstatement changes on one of the beams, and distance determined by application of the determined direction of movement to the known geometry of the object and beam.

28. A method according to Claim 20, wherein another of the movement characteristics is the direction of movement of the object relative to the intended direction; wherein the object commences or continues motion from a known position and at a known time; the measurement being associated with a determination of the ratio of the relative times, or differences in relative times, between changes in the beams and the time it commenced or continued motion from the known position.

29. A method according to Claim 28, wherein the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam has a fixed relationship to the angle of club face direction and angles of the beams.

30. A method according to either Claim 28 or Claim 29, wherein another of the movement characteristics is the speed of movement of the object; wherein speed is determined as distance divided by time, with time determined by the duration between the object effecting a change in one of the beams, and distance determined by application of the determined direction of movement to the known distance between the beam and the known position. 30a. are parallel to each other is approximately 75°. A method according to Claims 30, wherein the angle of cooperating beams which 30b. are parallel to each other is between 65° and 80°. A method according to Claims 30, wherein the angle of cooperating beams which 30c. A method according to Claims 30, wherein the difference in angle between cooperating beams which are disposed at different angles is approximately 10°. 35 IE 0408 30d. A method according to Claims 30, wherein the difference in angle between cooperating beams which are disposed at different angles is between 5° and 20°. 30e. A method according to Claims 30, wherein the distance between intersections between parallel pairs of cooperating beams is 50-60 mm. 30f. A method according to Claims 30, wherein the distance between intersections between parallel pairs of cooperating beams is between 40 mm and 70 mm.

31. A method according to any one of Claims 28 to 30, wherein the known position lies along the line of the intended direction.

32. A method according to any one of the preceding claims, wherein the beams comprise substantially flat elongate bands with a cross section where the width is far greater than the thickness. 32a. approximately 1 mm. A method according to Claims 32, wherein the beam has a thickness of 32b. to 2 mm. A method according to Claims 32, wherein the beam has a thickness of 0.5 mm

33. A method according to either Claim 31 or Claim 32, 32a or 32b , wherein the width of the cross section, is orthogonal to the common plane.

34. A method according to Claim 32 or Claim 33 , wherein a change is deemed to be an alteration to the beam, caused by an object entering any point on the cross section of the beam and partly obscuring it.

35. A method according to Claim 32 or Claim 33 , wherein a change is deemed to be an alteration to the beam, caused by an object departing the beam and ceasing to partly obscure it.

36. A method according to Claim 32 or Claim 33, wherein a beam is measured as the object passes through it; a record is made of the maximum measured degree to which the beam is obscured; IE 0408 and a determination is made of the position of an edge of the object relative to the width of the cross section of the beam using the record made of the maximum degree to which the beam is obscured.

37. A method according to Claim 32 or Claim 33, wherein two sets of beams are used to determine a movement characteristic of an object; one set operates over a shorter length along the direction of travel of the object than the other, but covers a wider range of angular variation in the plane which comprises the width of the cross section of the beam.

38. A method according to any one of Claims 32 to 37, wherein the transmitted thickness of the cross section of the beam is significantly greater than that which is required for measurement; the beam is such that measurement can be taken at a plurality of positions across the transmitted thickness of the cross section; and measurement is made using a cross section with a small dimension which is significantly less than the transmitted cross section.

39. A method according to Claim 38, wherein the measured thickness of the cross section of the beam is determined by screening the transmitted beam on the receiving side of the beam.

40. A method according to any one of the preceding claims, wherein the beams are electromagnetic wave beams.

41. A method according to any one of the preceding claims, wherein adjacent beams are pulsed and measured at different frequencies.

42. A method according to any one of the preceding claims, wherein measurement is made using artificial neural-type intelligence.

43. A method according to any one of the preceding claims, wherein the object is a ball or the face of an implement which strikes a ball. [E 0408

44. A method according to Claim 43, wherein the object is a golf ball or the face of a golf club.

45. Apparatus for measuring of the movement characteristics of an object by detection of changes in beams, the apparatus including a beam generating means, a beam detection means and a measurement means connected to the beam detection means, characterised in that there are at least two beam generating means and at least two beam detection means, each of which respectively comprises a beam emitting means which is operable to emit a beam and a beam detection means which is operable to detect a beam; the beam generating means being operable to dispose the beams in the path of the object; at relative angles to each other; and at acute angles to the intended direction of the object; the measurement means being operable to record the times of changes in beams, or durations between changes in beams; and the measurement means being operable to measure the movement characteristics using the relative times, durations or differences in relative times, at which different beams of the set are changed.

46. An apparatus according to Claim 45, wherein the beam generating means disposes at least one longitudinal element of the beams in a common plane.

47. An apparatus according to Claim 46, wherein the measurement plane is substantially horizontal.

48. An apparatus according to Claim 47, wherein the beam generating means disposes one beam at an acute angle clockwise to the intended direction and disposes the other beam at an acute angle counter clockwise to the intended direction.

49. An apparatus according to Claim 48, wherein the magnitude of the acute angles is equal 35 [E 0408

50. An apparatus according to any one of Claim 45 to 49, wherein the beam generating means disposes two beams such that they intersect at a point along the line of the intended direction

51. An apparatus according to any one of Claims 45 to 50 , wherein the object is an edge, or projected edge, which is orthogonal or near orthogonal to the intended direction of the object.

52. An apparatus according to Claim 51, wherein the edge is the projected leading edge of the face of an object and is substantially a straight line or slightly curved line.

53. An apparatus according to Claim 51 or Claim 52, wherein the beam generating means disposes the beams at acute angles to the intended direction of the object, of magnitude greater than the angle subtended between the edge and the intended direction of the object. 53a. An apparatus according to any one of Claims 51 to 53, wherein the angles of the beams, relative to the intended direction, exceed the maximum range of the angle of the edge, relative to the intended direction, over which measurement is made.

54. An apparatus according to any one of Claims 51 to 53, wherein the beam generating means generates a set of beams which comprises at least two pairs of parallel beams, with one pair disposed at a relative angle to the other pair; the measurement means is operable to measure the direction of movement of an edge relative to the intended direction; by determinations associated with the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair.

55. An apparatus according to Claim 54, wherein the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair has a fixed relationship to the angle of club face direction and angles of the beams.

56. An apparatus according to either Claim 54 or Claim 55, wherein the measurement means is operable to measure the speed of movement of the edge; |E0408 by determining speed as distance divided by time, with time determined by the duration between one end of the edge effecting successive changes on two parallel beams of one of the pairs of beams, and distance determined by application of the determined direction of movement to the known distance between the parallel beams.

57. An apparatus according to either Claim 55 or 56, wherein the beam generating means disposes the two pairs of parallel beams such that the intersections of both pairs lie along the line of the intended direction

58. An apparatus according to Claim 53, wherein the beam generating means generates a set of beams which comprises one pair of beams disposed in one rotation at different acute angles to the intended direction and a second pair of beams disposed in the opposite rotation at different acute angle to the intended direction; the measurement means is operable to measure the angle of the edge relative to the intended direction; by determinations which recognise that the angle of the edge is indicated closer to the angle of beams which are changed later and is indicated further from the angle of beams which are changed sooner; and an increased difference between relative changes between beams of opposite rotation progressively indicates the movement characteristic to be angle rather offset; and a reduced difference between relative changes between beams of the same rotation, progressively indicates the movement characteristic to be offset rather than angle.

59. An apparatus according to Claim 53. wherein the beam generating means generates a set of beams which comprises two beams disposed in one rotation at different acute angles to the intended direction and a third beam disposed in the opposite rotation at an acute angle to the intended direction; the measurement means is operable to measure the angle of the edge relative to the intended direction; by determinations which recognise that the angle of the edge is indicated closer to the angle of beams which are changed later and is indicated further from the angle of beams which are changed sooner; and an increased difference between relative changes between beams of opposite rotation progressively indicates the movement characteristic to be angle rather offset; 35 IE 0408 and a reduced difference between relative changes between beams of the same rotation, progressively indicates the movement characteristic to be offset rather than angle.

60. An apparatus according to Claim 53, wherein the beam generating means generates a set of beams which comprises one pair of beams disposed in one rotation at different acute angles to the intended direction and a second pair of beams disposed in the opposite rotation at different acute angles to the intended direction; the measurement means is operable to measure the offset of the edge relative to the intended direction; by determinations which recognise that the offset of the edge is indicated closer to the region comprising the most forward beam which are changed sooner and is indicated further from the region comprising beams which are changed later; and a reduced difference between relative changes between the two beams which are disposed in the same rotation, progressively indicates the movement characteristic to be offset rather than angle; and an increased difference between relative changes between beams of opposite rotation, progressively indicates the movement characteristic to be angle rather than offset.

61. An apparatus according to Claim 53, wherein the beam generating means generates a set of beams which comprises two beams disposed in one rotation at different acute angles to the intended direction and a third beam disposed in the opposite rotation at an acute angles to the intended direction; the measurement means is operable to measure the offset of the edge relative to the intended direction; by determinations which recognise that the offset of the edge is indicated closer to the region comprising the most fon/vard beam which are changed sooner and is indicated further from the region comprising beams which are changed later; and a reduced difference between relative changes between the two beams which are disposed in the same rotation, progressively indicates the movement characteristic to be offset rather than angle; and an increased difference between relative changes between beams of opposite rotation, progressively indicates the movement characteristic to be angle rather than offset. 35 lEo4oe1a 41

62. An apparatus according to any one of Claims 58 to 61, wherein the beam generating means disposes the beams such that they intersect at a common point which lies along the line of the intended direction

63. An apparatus according to any one of Claims 58 to 62, wherein the beam generating means disposes the beams such that the magnitudes of beams of opposite rotation are equal.

64. An apparatus according to Claim 50, wherein the object is of regular shape which is substantially independent of orientation, including a sphere, circle or point.

65. An apparatus according to Claim 64, wherein the beam generating means generates a set of beams which comprises at least two pairs of parallel beams, with each pair disposed at a relative angle to the other; the measurement means is operable to measure the direction of movement of the object relative to the intended direction; by determinations associated with the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair.

66. An apparatus according to Claim 65, wherein the ratio of the relative times, or differences in relative times, between changes in one parallel pair compared to another parallel pair has a fixed relationship to the angle of club face direction and angles of the beams.

67. An apparatus according to either Claim 65 or 66, wherein the measurement means is operable to measure the speed of movement of the object: by determining speed as distance divided by time, with time determined by the duration between the object effecting a changes on two parallel beams of one of the pairs of beams, and distance determined by application of the determined direction of movement to the distance between the parallel beams.

68. An apparatus according to any one of claims 65 to 67, wherein the beam generating means disposes the two pairs of parallel beams such that the intersections of both pairs lie along the line of the intended direction 35 IE 0408

69. An apparatus according to Claim 64, wherein the measurement means is operable to measure the direction of movement of the object relative to the intended direction; by measuring a change as the object first disrupts the beam and measures a second change when the beam is reinstated when the object passes through it; by determinations associated with the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam.

70. An apparatus according to Claim 69, wherein the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam has a fixed relationship to the angle of club face direction and angles of the beams.

71. An apparatus according to either Claim 69 or Claim 70, wherein the measurement means is operable to measure the speed of movement of the object; by determining speed as distance divided by time, with time determined by the duration between the object effecting a disruption and reinstatement changes on one of the beams, and distance determined by application of the determined direction of movement to the known geometry of the object and beam.

72. An apparatus according to Claim 64, wherein the measurement means is operable to measure the direction of movement of the object relative to the intended direction; where the object commences or continues motion from a known position and at a known time; by determinations associated with the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam.

73. An apparatus according to Claim 72, wherein the ratio of the relative times, or differences in relative times, between changes in one beam compared to the other beam has a fixed relationship to the angle of club face direction and angles of the beams.

74. An apparatus according to either Claim 72 or Claim 73, wherein the measurement means is operable to measure the speed of movement of the object; by determining speed as distance divided by time, with time determined by the duration between the object effecting a change in one of the beams, and distance determined by application of the determined direction of movement to the known distance between the beam and the known position. 35 IE 0403

75. An apparatus according to any one of Claims 72 to 74, wherein the known position lies along the line of the intended direction. 75a. An apparatus according to Claims 75, wherein the angle of cooperating beams which are parallel to each other is approximately 75°. 75b. An apparatus according to Claims 75, wherein the angle of cooperating beams which are parallel to each other is between 65° and 80°. 75c. An apparatus according to Claims 75, wherein the difference in angle between cooperating beams which are disposed at different angles is approximately 10°. 75d. An apparatus according to Claims 75, wherein the difference in angle between cooperating beams which are disposed at different angles is between 5° and 20°. 75e. An apparatus according to Claims 75, wherein the distance between intersections between parallel pairs of cooperating beams is 50-60 mm. 75f. An apparatus according to Claims 75, wherein the distance between intersections between parallel pairs of cooperating beams is between 40 mm and 70 mm.

76. An apparatus according to any one of Claims 45 to 75, wherein the beam generating means are operable to generate beams which comprise substantially flat elongate bands with a cross section where the width is far greater than the thickness.

77. An apparatus according to either Claim 75 or Claim 76, wherein the width of the cross section, is orthogonal to the common plane. 77a. An apparatus according to Claims 77, wherein the beam has a thickness of approximately 1 mm. 77b. An apparatus according to Claims 77, wherein the beam has a thickness of 0.5 mm to 2 mm. lEo4os1e 44

78. An apparatus according to Claim 76 or Claim 77, wherein the measurement means is operable to deem a change as an alteration to the beam, caused by an object entering any point on the cross section of the beam and partly obscuring it.

79. An apparatus according to Claim 76 or Claim 77, wherein the measurement means is operable to deem a change as an alteration to the beam, caused by an object departing the beam and ceasing to partly obscure it.

80. An apparatus according to Claim 76 or Claim 77, wherein the measurement means is operable to measure a beam as the object passes through it; and make a record of the maximum measured degree to which the beam is obscured; and make a determination of the position of the edge of the object relative to the width of the cross section of the beam using the record made of the maximum degree to which the beam is obscured.

81. An apparatus according to claims Claim 76 or Claim 77, which comprises two beam generating means. each of which is operable to detennine a movement characteristic of an object; where one operates over a shorter length along the direction of travel of the object than the other, but covers a wider range of angular variation in the plane which comprises the large dimension of the cross section of the beam.

82. An apparatus according to Claim 76 or Claim 77, wherein the emitter means is operable to generate a beam where the thickness of the cross section is significantly greater than that which is required for measurement; the beam is such that measurement can be taken at a plurality of positions across the transmitted cross section; and the measurement means is operable to determine measurements using a cross section with a thickness which is significantly less than the transmitted cross section.

83. An apparatus according to Claim 82, which includes a screening means which determines the measured thickness of the cross section of the beam on the receiving side of the beam. 35 lEo4osis 45

84. An apparatus according to any one of Claims 45 to 83, wherein the emitter means is operable to generate beams as electromagnetic wave beams and where the detection means is operable to detect such beams. 84a. An apparatus according to Claim 84, wherein the emitting means includes an emitter which is a laser diode. 84b. axes of divergence and the axis of greatest divergence is aligned to the width of the beam A apparatus according to Claim 84a, wherein the laser diode comprises different and the axis of lesser divergence is aligned to the thickness of the beam. 84c. An apparatus according to Claim 84a, wherein the laser diode emits radiation of near infrared wavelength.

85. An apparatus according to Claim 84 or 84a to 84c, wherein the emitting means includes a lens which modifies the beam from an emitter

86. An apparatus according to Claim 85, wherein the lens is operable to focus a beam of two different divergence axes such that the axis of lesser divergence is focused into beam with a much smaller degree of convergence.

87. An apparatus according to Claim 85, wherein the lens is operable to focus a beam of two different divergence axes such that the axis of greater divergence is focused to beam with greater divergence.

88. An apparatus according to Claim 85, wherein the lens is operable to modify a beam which varies in intensity across its cross section, by relative positive magnification of areas of lower intensity and relative negative magnification of areas of higher intensity.

89. An apparatus according to any of Claims 84 to 88. wherein the emitting means includes a reflecting means.

90. An apparatus according to Claim 89, wherein the reflecting means is operable to focus a diverging beam into a parallel or near parallel beam. 35 IE0./.03

91. An apparatus according to Claim 89, wherein the reflecting means is operable to focus a diverging beam into a parallel or near parallel beam with a small degree of divergence.

92. An apparatus according to Claim 89, wherein the reflecting means is operable to focus an obliquely incident diverging beam into a parallel or near parallel, substantially orthogonal, beam with a small degree of convergence.

93. An apparatus according to any of Claims 84 to 92, wherein the detection means includes a reflecting means.

94. An apparatus according to Claim 93. wherein the reflecting means is operable to focus a near parallel beam onto a detector.

95. An apparatus according to Claim 93, wherein the reflecting means is operable to focus a parallel or near parallel beam which is substantially orthogonal, to an obliquely incident converging beam onto a detector.

96. An apparatus according to Claims 89 or 93, wherein the reflecting means is of substantially flat shape and comprises an array of reflecting facets.

97. An apparatus according to the preceding claim, wherein the reflecting means comprises a plurality of arrays of reﬂecting facets.

98. An apparatus according to either of Claims 96 or 97, wherein the reflecting means comprises a polymer injection moulding.

99. An apparatus according to Claims 89 or 93, wherein the reflecting means is interchangeable and is provided in different sizes or arrangements which are operable to produce beams or sets of beams of different sizes or arrangement.

100. interchangeable and the apparatus is provided with a plurality of mounting positions for a An apparatus according to Claims 89 or 93, wherein the reflecting means is reflecting means, disposed at different distances from the ball starting position. 35 IE 0408

101. An apparatus according to Claims 89 or 93, which includes an emitter reflector and a detection reflector, wherein the emitter reﬂector is operable to focus a beam to the detection reflector, the detection reflector is operable to receive it, and the height or long dimension of one of the reflectors is greater than the height or long dimension of the other reflector.

102. A focusing means according to any of Claims 84 to 101, wherein focused reflection by a reflecting means is replaced by focused transmission by a lens.

103. operable to generate adjacent beams which are pulsed at different frequencies and where An apparatus according to any of Claims 84 to 102, wherein the emitter means is the measurement means is operable to measure at the frequency of the corresponding emitter means and to disregard beams detected at other frequencies.

104. An apparatus according to any of Claims 84 to 103, wherein the measurement means includes an electronic processor means which includes an analogue trigger which is operable to determine the initial interruption of a beam.

105. includes a Schmitt trigger which activates when a voltage output from a photodiode falls An apparatus according to the preceding claim, wherein the analogue trigger by a small preset amount below a steady state level

106. means includes an electronic processor means which is operable to track the output of a An apparatus according to any of Claim 84 to 105, wherein the measurement detector, such as a photodiode, at high speed, and to record its lowest value.

107. An apparatus according to the preceding claim, wherein the measurement means is operable to determine a position of the object in relation to the beam by comparing the lowest value, relative to the steady state signal which was present before or after the beam was interrupted and comparing it to a set of conversion values.

108. means includes an artificial neural-type intelligence means. An apparatus according to any one of Claims 45 to 107, wherein the measurement 108a. An apparatus according to any one of Claims 45 to 108, wherein elements of the detecting means, including the detectors, are positioned below the level of the beams. 35 E 0408 108b. An apparatus according to any one of Claims 45 to 108, wherein elements of the emitting means, including the emitters, are positioned below the level of the beams.

109. An apparatus according to according to any one of Claims 45 to 108b, wherein each beam generating means comprises one emitter and one detector.

110. wherein the emitters and detectors are located on opposite sides of the commencing An apparatus according to Claim 109, which includes an emitter reflection means, position of the ball.

111. An apparatus according to Claim 110, wherein which includes an emitter reflection means, wherein each emitter is located forward of the beam with which it is associated, and the emitters and detectors are located on the same side of the commencing position of the ball.

112. reflection means, wherein the beam generating means share one or more common An apparatus according to any of Claims 45 to 108b, which includes an emitter emitters; and the common emitters are located forward of the beams and on the same side of the ball starting position as the detection means.

113. ball or the face of an implement which strikes a ball. An apparatus according to any one of Claims 45 to 112, wherein the object is a

114. An apparatus according to Claim 113, wherein the object is a golf ball or the face of a golf club.

115. herein described with reference to the accompanying drawings. A method of measuring the movement characteristics of an object substantially as

116. Apparatus for measuring the movement characteristics of an object substantially as herein described with reference to, and as shown in, the accompanying drawings. MACLACHLAN 8. DONALDSON, Applicant's Agents, 47 Merrion Square, DUBLIN 2.