WO2014106751A1

WO2014106751A1 - Sports training aid

Info

Publication number: WO2014106751A1
Application number: PCT/GB2014/050015
Authority: WO
Inventors: John Edwin FILER
Original assignee: Filer John Edwin
Priority date: 2013-01-04
Filing date: 2014-01-03
Publication date: 2014-07-10
Also published as: GB201300154D0

Abstract

The present invention relates to an apparatus for providing visible images of the position of a rapidly moving golf club (23) or golf club substitute, wherein the apparatus comprises a golf club or golf club substitute and a stroboscopic light source (11), the golf club or golf club substitute includes a contrast surface, and wherein, in use, the stroboscopic light source is positioned to shine light on the contrast surface and the contrast surface is positioned to reflect the light to the golf club or golf club substitute user's eyes, and wherein the contrast surface is either (i) a retro-reflective surface or (ii) a surface having a higher reflectivity than the surface immediately surrounding the contrast surface. The present invention also relates to a kit of parts, a method of showing the movement of a swinging golf club or golf club substitute, and use of a stroboscopic light with a golf club or golf club substitute.

Description

Sports Training Aid

Technical Field

The present invention relates to the use of a reflective surface on sporting equipment to improve technique, sports equipment including a reflective surface

Background

Many sports involve the use of a club or a bat to hit a projectile, and much of the skill on the game depends upon the ability of the player to hit the projectile cleanly and accurately. However, due to the limitations of the human visual system and the speed of the motion the actual swing, the swing and impact are obscured from the direct perception of the player.

For example, anyone who has spent time either playing golf or practicing their shots at a driving range will have been frustrated by the fact that when you hit the ball it does not always travel in the direction intended or travel as far as expected.

The frustration is compounded by the fact that most of the time the golfer is unable to determine what they did wrong to cause the error in the ball's path. In golf, a primary ability of the player is measured in the power and the accuracy of their shots. A drive shot is one where the distance to the pin is greater than the distance the golfer can hit the ball. When making a drive shot there is a trade-off between power and accuracy. As a player nears the limit of their maximum power their ability to control their swing and hit the ball accurately is reduced.

A conventional method of practising drive shots and learning the optimum

compromise of power and accuracy is to use a 'driving range' where the player repeatedly makes the same shot and observes the flight of the ball to deduce the quality of the shot. At many driving ranges are additional facilities to allow the golfer to practice pitching, chipping and putting shots. Repeatedly making the same shot develops the golfer's 'muscle memory' where the co-ordinated steps of the swing become a single smooth and repeatable action. This allows the golfer more control over the swing. The golf swing is a highly complex motion incorporating most muscle groups of the body co-ordinated to accelerate the club head as fast as possible whilst maintaining control of its position at the time of impact with the ball. The action of the swing comprises a number of stages including the backswing, the downswing, impact and follow -through.

During a golf swing the head of the club is accelerated to speeds around 150 kph. To achieve this, the golfer needs to rapidly expend energy firstly in accelerating the club head to impact, and then to decelerate the club during the follow through. During a swing the golfer can momentarily reach power outputs of over 3KWatts.

At the moment of impact it is difficult to comprehend how accurately the ball has been struck. With skill it is possible to observe the path of the ball and deduce the most likely cause of any error. However after doing so, mapping the complex muscle motion to the position of the club at impact is difficult for the mind to achieve and consequently learning to hit a golf ball accurately takes an inordinate amount of practice.

With practice, the ability to consistently repeat the swing action is improved. This repeatability is also known as 'a groove' whereby a practiced golfer can keep within the groove when making a shot.

Equally important to the golfer developing 'the groove' is feedback, whereby the observed flight of the ball, together with other observations allow the golfer to determine the quality of each shot. Thereby, over time, the golfer is able to improve the consistency and accuracy of their shots by making adjustments.

Although the use of driving range facilities is the conventional method for practising golf there are a number of problems with this type of practice:

Resetting for the shot: Prior to each shot the golfer must place a ball on the tee. The action of moving from the 'stance' to place a ball and then return to the stance degrades the ability of the golfer to obtain an identical stance between one swing and the next. Resetting for the shot. The delay between each shot degrades the ability of the golfer to compare one swing with the next.

The club head is travelling at high speed as it passes in front of the golfer. Due to this speed and the motion blur of the club it is not possible for the golfer to determine a) the alignment of the centre of the club face with the centre of the ball at impact, b) the angle of the club face as it impacts the ball, and c) the direction of movement of the club face as it impacts the ball.

When making a drive shot one of the actions the golfer makes during the downswing is a pivoting of the wrists, which increases the speed of the club head. This action is known as 'uncocking the wrists'. During this uncocking, the head of the club rotates around an axis along the shaft of the club. Due to the motion blur, it is extremely difficult for the golfer to ascertain the accuracy of the timing of uncocking the wrist and the consequent club head rotation. Without having timely feedback on the quality of the shot, the golfer needs to resort to trial and error to obtain the 'feel' of the correct timing. As there are many muscle actions in the golf swing, it is not clear which action caused an error in the golf swing, therefore trial and error requires a substantial number of attempts to allow the golfer to improve their swing. Hence the years of practice required to become a golf professional.

The primary source of feedback on the success of the swing is obtained by the golfer observing the flight of the ball. However there may be a number of errors which contribute to any error in the flight of the ball. For example the ball could travel more to the left because the line direction of the swing was incorrect, because the face of the club was angled to the left when it struck the ball, or because spin was imparted to the ball during the shot which caused it to move to the left. The other problems with using the observed flight of the ball as the primary source of feedback are the delay between making the swing and the observation as well as the golfer having to mentally draw a conclusion as to the nature of the error of the swing which caused the error of flight. Without good primary feedback the golfer may be practising and achieving a 'groove' for a swing action which contains two or more errors which have compensating effects. However when the golfer tries a different shot using the same action the value of each of these errors may combine differently resulting in a poor shot from the same action.

To alleviate some of the above problems with use of a driving range to practice a golf swing a number of inventions have attempted to alleviate one or more of those problems.

Various devices have been invented to constrain one or more of the golfer's movements to those normally observed in the swing of an expert golfer. For example a head constraint which holds the head in a fixed position during the swing, the aim of restraining erroneous movement is that the golfer should achieve muscle memory of an improved golf action. In fact many professional golfers have perceived

eccentricities in their swings but still achieve good results. Movement constrainers do not help the golfer practice good swings but reduce the likelihood of the golfer practising bad swings. Movement constraint devices seek to improve the appearance of a golfer's swing but do not primarily address the errors of the club face impacting the ball.

Video-taping or motion capture of a golfer's swing and replaying the action in slow motion allows any deviation by the golfer from a perceived ideal swing to be ascertained. Thus allowing the golfer to correct their swing. However, the feedback is delivered sometime after the actual swing. Normally meaning the golfer has changed position (stance) thus making it more difficult for the golfer to make small adjustments based on their last swing. This type of invention improves the

choreography (i.e. the visual appearance) of a swing, but does not primarily address the errors in the positioning and alignment of the club face as it impacts the ball, and it is the impact errors which affect the actual flight of the ball.

Statement of Invention

At its most general, the present invention provides an apparatus for providing visible images of the orientation of moving sports equipment using a stroboscopic light wherein said sports equipment comprises a contrast surface. In particular, the present invention provides an apparatus for providing visible images of the position of a rapidly moving golf club or golf club substitute, wherein said apparatus comprises a contrast surface on a golf club or golf club substitute. The present invention allows a golf club user to visually track the golf club (or substitute) through their field of vision during a golf swing without the use of cameras.

In a first embodiment, the present invention provides an apparatus for providing visible images of the position of a rapidly moving golf club or golf club substitute, wherein the apparatus comprises a golf club or golf club substitute and a stroboscopic light source, wherein the golf club or golf club substitute includes a contrast surface positioned to reflect light to a user's eyes and the stroboscopic light source is positioned, in use, to shine light on the contrast surface, and wherein the contrast surface is either (i) a retro-reflective surface or (ii) a surface having a higher reflectivity than the surface immediately surrounding the contrast surface.

The term "golf club substitute" as used in the present application means any device designed to imitate a golf club for training purposes. The term "retro-reflective surface" means a surface that principally reflects light back to its source. In other words, more than 50% of the light reflects back to its source.

The images produced by the invention will be more visible if the sports equipment is used against a dark or low reflectivity background. The invention relies on the contrast between the images produced and the background. With the correct alignment of user and light the contrast surface can reflect light with an efficiency (reflective index) in excess of 900 times brighter than a white surface. A standard black background can have a reflective index of 5% (i.e. l/20th that of a white surface). So the difference in the return of the stroboscopic light between the contrast surface and a dark coloured or black background is around 18,000 times. Dark coloured surfaces have significantly lower reflectivity than white surfaces.

With a stroboscopic flash duration of 1/lOOOOth of a second and a persistence of vision of about l/25th of a second the amount of ambient light falling on the background can be approximately 10 times more intense than the stroboscope for the contrast (between the lighter image and the darker background) to be around 4.5 (a contrast readily visible to the human eye).

This has the effect that a relatively small, low powered stroboscope can generate images with sufficient contrast between the contrast surface and the background to allow those images to be visible under normal ambient lighting conditions. These images are provided in real time allowing the golfer to strongly link the muscle movements with the alignment of the club at impact and the accuracy of the shot. In an embodiment of the first aspect, the contrast surface comprises one or more lines or geometric patterns. In this way the contrast surface readily allows the orientation, alignment and direction of movement of the sports equipment, e.g. golf club, to be ascertained. The contrast surface may be adhered to the surface of the sports equipment.

Alternatively, the contrast surface can be painted onto the surface of the sports equipment. Further, the contrast surface may be integrated into the sports equipment.

In some embodiments, the contrast surface is located on the head of the golf club. In preferred embodiments, the contrast surface is located on an upper surface (in use) of the head of the golf club or golf club substitute. In this way, the contrast surface readily reflects the stroboscopic light back to the user's eyes.

Preferably, the apparatus includes a dark coloured and/or low reflective surface background. Additionally, if the surface of the club head surrounding the contrast surface is also dark coloured, it will allow the created images to be more visible. In some embodiments, a dark coloured and/or low reflective surface coating or paint is applied to provide the background surface. Alternatively, the background may be a dark coloured and/or low reflective mat.

In some embodiments, the background is marked with reference lines or geometric patterns. In these embodiments, the user can more readily determine the accurate orientation, alignment and direction of movement of said visible images whilst the sports equipment is in use. When the apparatus includes a stroboscopic light, the stroboscopic light may be mountable or mounted so that in use it shines substantially along the user's line of sight. For example, the stroboscopic light may be mountable or mounted on a unit to be worn about the head of a user (e.g. a hat or a head band). More particularly, the stroboscopic light may be mountable or mounted on the peak of a cap.

Preferably, the contrast surface is a retro-reflective surface. The retro-reflective surface reflects a large proportion of the stroboscopic light, and so may be used in bright conditions.

The contrast surface may be a surface having a higher reflectivity than the surface immediately surrounding the contrast surface. In these embodiments, the contrast surface may be a white surface and the area immediately surrounding the contrast surface is dark coloured. The area immediately surrounding the contrast surface may be any dark colour, and such dark colours are well known per se. Examples of dark colours include black, dark brown and dark blue.

In a second aspect, the present invention provides a kit of parts comprising a stroboscopic light source and a contrast coating for applying to the head of a golf club. The kit of parts may also include a mat having contrast markings.

In a third aspect, the present invention provides a method of showing the movement of a swinging golf club, comprising the steps of: mounting a stroboscopic light in a predetermined position so that it shines substantially along the line of sight of a golfer using the invention, and using a golf club with a contrast surface. The method may also include the step of applying a contrast surface to the head of the golf club.

In a fourth aspect, the present invention provides a use of a stroboscopic light with golf club or golf club substitute including a contrast surface. Such a use allows a golf club (or substitute) user to visually track the golf club (or substitute) through their field of vision during a golf swing without the use of cameras.

The apparatus of the present invention has the following advantages: • The device allows you to directly see the position and angle and direction of the club as it passes in front of you (see, for example, Fig.2 Item 27).

• Seeing the club position at the moment the club strikes the ball provides a very efficient mechanism for feedback on the accuracy of the swing. This allows the user to improve their golf swing at much more quickly than traditional practice.

• You can use the device without a golf ball, so you can practice full power swings anywhere you can safely swing a golf club.

• You can practice full power swings and thus develop muscle memory for those swings.

• Without the need to use a ball you can immediately repeat your swing and quickly make adjustments to your swing to correct any errors.

• Making repeated full power swings gives you aerobic exercise, developing muscle strength and power, also desirable for playing golf.

· As you can make one swing immediately after the other you don't change your stance so the effect of any correction to your swing has a stronger correlation with the observed results. This improved feedback also allows the user to benefit more from any practice session.

• Once you achieve the ability to regularly hit the tee accurately, the practice can be extended by increasing the power in your swing.

• There is no need for expert analysis of your swing. You can see the accuracy of the swing with your own eyes.

• An instructor can use the same device to observe the swing accuracy of a pu- pil.

· A small pocket version of the device would work satisfactorily in most ambient lighting conditions. A more powerful version could be employed on very bright days.

• You can have effective swing practice at home or at the office, negating the need to drive to the golf club. Meaningful practice can be achieved in sessions only lasting 10 to 20 minutes, enabling you to practice two or more times a day.

• Typically, practice at the driving range generally requires a couple of hours out of your day. After making the effort to get there you will practice even after you have tired your muscles and therefore you will be practicing a swing which is suited to tired muscles.

• Without the time and effort of getting to the driving range and setting up to practice, the user is more likely to be prepared to stop once they tire, and resume practice once they are rested. Consequently you spend more time practicing (and hence developing muscle memory for) when your muscles are fresh (i.e. nearer the conditions encountered during a round of golf).

• The device is pocket sized so you can carry it discreetly.

• Using a driving range costs money each time. This device will provide hours of practice for many years.

• Practice in the privacy of your own home/garden rather than under the critical eye of the users at a public driving range.

• The contrast surface lines do not add any significant weight to the club head, and you can practice with your normal set of golf clubs.

Description of Figures

Figure 1 shows an example of a use of an embodiment of the invention.

Figure 2 shows a schematic of the observable images of the head of a golf club as it may appear to the user during a golf swing.

Figure 3 shows some possible locations of the stroboscopic light when in use.

Figure 4 shows two possible contrast surface shapes/patterns mounted on the head of a golf club.

Figure 5 shows three possible errors in positioning the club head as it strikes a ball. Detailed Description

The invention will now be described with reference to the following figures. Figure 1 shows a stroboscopic light (11.) and the location of the contrast surface on the sports equipment (13.). Also shown is a possible configuration of cone of illumination (15.) from the stroboscopic light, and showing the path of the light (21.) returned from the contrast surface towards to the golfer's eyes. Figure 1 also shows a practice mat (17.) used which has reference lines (one shown 19.).

Figure 2 shows an artistic interpretation of the observable images (27.) of the head of a golf club (23.) as it may appear to the user during a golf swing. Also shown is the stroboscopic light (21.) mounted on the user's head, the cone of illumination (25.) from that light.

Figure 3 shows a schematic showing some possible locations of the stroboscopic light which is mounted near a line originating at playing area (33.) and passing through the user's centre of vision. Those positions shown are; (31.) mounted on a hat worn by the golfer, (35.) mounted in front of the golfer (either mounted on the floor 35.1 or on a nearby vertical surface 35.2) or ceiling mounted behind the golfer either on a stand (37.1) or incorporated into a standard lighting fixture (37.2).

Figure 4 shows two possible contrast surface shapes/patterns mounted on the head of a golf club. These are a single bar (41.) and an additional pattern consisting of three bars (47.). Also shown is the pattern of images generated by the invention as each club head passes over the dark coloured (low reflection) background. Club head 43. (oriented correctly and containing a single bar of retro-reflectivity) moved in the direction of the arrow will produce the image pattern shown in 43.1.

Club head 45 is identical to club head 43 except the club is rotated slightly clockwise (i.e. incorrectly aligned for a good shot). The pattern of images generated by club head 45 is shown in 45.1, where it can be noticed that the line has a saw tooth edge. Likewise the contrast surface pattern on correctly aligned club head 49 will give the symmetrical pattern 49.1 whereas club head 51 which is rotated clockwise (i.e.

incorrectly aligned for a good shot) will result in the distinctive pattern 51.1. Figure 5 shows three possible errors in positioning the club head as it strikes the ball. 51 shows the ball not being struck by the centre of the club head (i.e. incorrectly aligned). 52 shows the direction of the swing not being correct (i.e. incorrect direction). 53 shows the club head rotated so that it does not hit the ball square (i.e. incorrect orientation).

Types of golf shots

When playing a game of golf the game is divided into a number of types of club swings.

• Driving from the tee • Approach shots

• Pitching

• Chipping

• Putting

Driving and approach shots use a similar full swing action, the primary difference is that when driving the ball it is mounted on a tee.

Drive Shots - having the ball mounted on a tee allows the golfer to use a larger club head without the club catching either the ground or the grass. With a larger club face, it is more likely that the ball is hit accurately. Consequently the golfer can use more power before losing control of the shot.

Approach shots - generally these use a club with a smaller head (an iron). As the ball lies on the ground, the grass will interfere with the club during the shot, a smaller club head reduces the amount of interference due to the grass. On an approach shot the iron selected will depend on the distance the golfer wants to hit the ball. An iron with a greater angle will cause the ball to travel much more vertically and so the horizontal distance the ball travels will be less.

So for drive shots and approach shots the golfer uses a 'full swing' action with the same level of power. Having practiced this one action so that it can be made with a high level of repeatability, the golfer is able to make accurate shots in the range from 100 to 250 metres.

Pitching - For shots less than 100 metres the golfer uses an iron and the same full swing action, but will make the swing slower thus moderating the amount of power used. Chipping - for short distances a full swing is not required and the golfer locks the position of the arms against his/her body and makes the swing using rotation of the back and hips. Using this constrained motion reduces the number of errors in the swing. Putting - an even more constrained action using a club with a vertical club face to hit the ball along the ground on the 'green' .

This device primarily benefits the golfer in practicing, drive and approach shots although pitching and chipping can also benefit.

The full swing action

To maximise the distance the ball travels the purpose of the swing is to accelerate the club head so that it is travelling at its maximum at the time it arrives at the tee. The golfer employs their legs, hips, back, shoulders and arms in the swing and the motion of each of body part changes throughout the swing.

A lot of traditional golf instruction concentrates on the choreography of the swing, to help increase the power and accuracy of the swing.

However the ultimate purpose of all the choreography is to get the golfer to present the club head at the tee with maximum force and accuracy. Allowing the golfer to 'see' the club head as it passes the tee will allow them to develop their action in a more intuitive manner. Actually an intuitive approach to developing a golf swing is used by a number of golf instructors.

The present invention uses two physical components identified in the following two paragraphs. First, a stroboscopic light (see, for example, Fig.3 Items 31, 35, 37.1 and 37.2) is mounted near a line (see, for example, Fig.3 Item 39) whose origin is the contrast surface on the sports equipment and which passes through a point between the user's centre of vision (i.e. part way between the user's eyes). The light may be mounted in front of the user, it may be mounted on the user, or it may be mounted above and behind the user.

Second, a high visibility contrast surface on the sports equipment, e.g. golf club (see, for example, Fig.3, Item 33). For example, the contrast surface may be a retro- reflective surface is one where the incident light is primarily reflected back in the direction of the light source. The surface could be achieved by using any retro- reflective technology.

In addition to these two components the invention uses the 'persistence of vision' of the human eye, whereby a moving object transmitting a highly illuminated image for short duration (such as provided by the apparatus of this invention) will appear momentarily 'frozen' allowing the orientation of the object to be discernible. Fig. 2, Item 27 shows a schematic of those images of the club head. The images produced by the invention will be more visible if the sports equipment is used against a dark or low reflectivity background (Fig.4 Item 43.1). The invention relies on the contrast between the images produced and the background. With the correct alignment of user and light the retro-reflective surface can reflect light with an efficiency (reflective index) in excess of 900 times brighter than a white surface. A standard black background can have a reflective index of 5% (i.e. 1/20^ώ that of a white surface). So the difference in efficiency of the return of the stroboscopic light between the retro-reflective surface and the background is around 18,000 times.

When using a retro-reflective surface with a reflective index of 900, and a tee background with a reflective index of 0.05 and a stroboscopic flash duration of 100 micro seconds, images of the club head are visible when the intensity of the strobe light is 5% or more that of the incident ambient light.

With a stroboscopic flash duration of 1/lOOOOth of a second and a persistence of vision of about l/25th of a second, the amount of ambient light falling on the background can be approximately 10 times more intense than the stroboscope for the contrast (between the lighter image and the darker background) to be around 4.5 (a contrast readily visible to the human eye). This has the effect that a relatively small, low powered stroboscope can generate images with sufficient contrast between the retro-reflective surface and the background to allow those images to be visible under normal ambient lighting conditions. These images are provided in real time allowing the golfer to strongly link the muscle movements with the alignment of the club at impact and the accuracy of the shot.

Retro-reflective surfaces are known, per se, and examples of retro-reflective surfaces include:

• Inverted cube corners such as the red or white reflectors found on motor vehicles;

• 'Cat eye' type reflectors used on the highways; and

• Spherical glass beads as common in reflective paints used in road markings. Any retro-reflective surface may be used in the present invention.

A battery powered stroboscope utilising LED lights could be mounted on the peak of the golfer's baseball cap. Strips of self-adhesive contrast tape could be applied to the upper surface of the golf club head.

Not only will this invention be portable but the strobe light can be made small enough for the golfer to carry it around inside clothing pockets or in the golf cart. Its portability and its simplicity make this invention convenient to use. The present invention provides the trainee with an individual, low cost training aid that can be employed anywhere golf practice is normally carried out including on a convention driving range facility. As the invention allows valuable practice without the use of a ball, this considerably increases the number of locations suitable for practice and allows the user to retry the swing immediately without having to change their stance.

Accordingly the invention provides for an apparatus providing an optical feedback mechanism for perceiving the movement of an article comprising a stroboscopic light source and a reflective component, said reflective component being attached to the article, wherein the stroboscopic light source is mounted substantially along the line of sight of the user. The reflective component might be strips of contrast material adhered to the head of an existing golf club, or the club could be specially prepared with the strips as a design feature. Alternatively the reflective component could be painted on to the club. In order to ensure that the strobe is mounted near line of sight, the light can be affixed about the head or in the brim or the peak of a hat. These could for example be clipped on to a peaked baseball cap.

Where the stroboscopic light is mounted on the golfer it would be mounted near the line of sight of the golfer. If not mounted on a hat, it could be mounted on a spectacle frame, on a head band, or other device to affix the light to the head.

Where the stroboscopic light is mounted not on the golfer, it could mounted either above and behind the golfer or in front of and below the head of the golfer.

Alternatively the actual source of the light could be located elsewhere and the light delivered by use of mirrors, optical fibres or some other technology to simulate the location of light previously described.

A golfer's existing golf clubs can readily be modified for use by this invention. The modification would carried out by the application of contrast tape to the upper surface of the head of each golf club.

The light unit and the reflective component could be supplied as a kit that can be used to modify existing equipment fairly easily.

Also modified golf clubs could be manufactured. The advantage of purpose built golfing equipment is that the contrast surfaces could be made more robust, more protected, more permanent. An accurate swing is one where the centre of the club face impacts the centre of the golf ball, the club face is perpendicular to the required direction of the ball and where the direction of the swing is aligned with the required direction. The accuracy of the movement of the club is not normally visible at the time that the ball is impacted, so the golfer must use the path of the flight of the ball and the sound of the impact as the means to deduce any error. Using these indicators the nature of any alignment error is not readily intuitive, and not easily comprehended especially by the novice golfer. In addition the flight of the ball will take a number of seconds which means the realisation of the cause of the error is also delayed which

significantly reduces the value of the feedback compared with a image showing the orientation of the club as it passes in front of the user. Due to the difficultly in seeing the club head in real time, many professionals have resorted to using a video camera and having the video interpreted by a skilled trainer or alternatively they have subjected themselves to direct observations of a skilled trainer. The observer or video analysis is then used to correct any observed deviations from a 'standard golf swing' .

Video analysis and the use of a skilled sports trainer will result in a delay initially for the swing to be assessed and then the result communicated to the golfer. This set up has the disadvantage that it cannot readily be used on a conventional driving range due to the restrictions in space in each driving 'cell'.

Much traditional 'golf swing improvement' concentrates on getting the golfer to develop a 'perfect swing' . However there are many professional golfers who use an unorthodox swing with excellent results. The achievement of the 'perfect swing' is not primarily what generates an accurate shot, in reality the flight of the ball depends entirely on the speed, angle and alignment of the club during the impact with the ball.

Rather than aiming to improve the look of a golfer's swing, this invention primarily will assist and correct the golfer in achieving the club accurately impacting the ball, consequently this results in a more rapid improvement on the golfer's actual performance.

The reflective component might be strips of contrast surface material adhered to the head of an existing golf club, or the club could be specially prepared with the strips as a design feature. Alternatively the reflective component could be painted on to the club.

The alignment of and the stroboscopic effect of the light, the nature of the contrast surface and the 'persistence of vision' of the human eye will result in a number of visible images of the contrast surface as the club passes in front of the golfer during a golf swing. With suitable component parts, the invention allows the images of the club to be visible under any normal ambient conditions, even full sunshine. The images will allow the golfer to readily comprehend any errors in the angle and position of the face of the club as it approaches the tee during a golf swing. The images will also allow the golfer to ascertain the direction of the swing and it's alignment with the tee. Not only will this invention be portable but the strobe light can be made small enough for the golfer to carry it around inside clothing pockets or in the golf cart. Its portability and its simplicity make this invention convenient to use.

In order to ensure near line of sight, stroboscopic lights can be affixed about the head or in the brim or the peak of a hat. These could for example be clipped on to a peaked baseball cap. Where the invention employs led stroboscopic lights, the battery power required is minimal so the weight is small.

Alternatively the actual source of the light could be located elsewhere and the light delivered by use of mirrors, optical fibres or some other technology to simulate the location of light previously described. A golfer's existing equipment can readily be modified for use by this invention. The modification could be carried out by the application of contrast surface tape to the upper surface of the head of each golf club.

Also modified golf clubs could be manufactured. The advantage of purpose built golfing equipment is that the contrast surfaces could be made more robust, more protected, more permanent.

The following description outlines some of the considerations which will need to be made in the production of a usable embodiment of this invention.

The most difficult shot to perfect in golf is the drive, as the golfer typically is hitting the ball near the limits of their strength and at such times the ability for the golfer to control their muscle co-ordination is compromised. Due to the ability of this invention to allow the club orientation to be observed during a high speed swing this device gives greatest assistance to practising the swing.

When a golfer hits the ball during a 'drive' shot, the club head is travelling at speeds approximately 130 to 150kph (80 to 90mph).

The bursts of light from the stroboscope would have a repeating frequency which would give several visible images of the club head as it swings near the ground. For example a stroboscopic rate of 1kHz will result in about 20 images being produced as a club head moving at 160kph (lOOmph) passes through a distance of one metre.

Using a similar club speed, during a stroboscopic flash of about 1/10,000 of a second the club will travel a distance of about 1cm, which will provide a suitably 'stationary' image to allow the golfer to establish the orientation of the club head. The invention uses the 'contrast' between the contrast surface "images" of the club and the background. Using dark colours and/or low reflective surfaces on the club and on the tee area will make the contrast surface images easier to see. In existing stroboscopic inventions increasing the power of the stroboscope equally serves to increase the illumination of the tee area, and does not improve the contrast of the club images against the background

Using retro-reflective technology an increase in the power of the stroboscope results in an increase in the 'contrast' of the image against the background.

The darker the background, the lower the ambient light the more the contrast surface images will be apparent. The closer the light is to the line connecting the golfer's eyes to the tee the more efficient the light is returned from a retro-reflective contrast surface.

The use of the 'persistence of vision' in this manner is not in common use and therefore a user of this system may require some practice before they are fully able to efficiently assimilate the information presented by the images the invention produces and therefore to obtain maximum feedback on the accuracy of their swing.

After practising, the invention can be successfully used when ambient lighting conditions are not ideal, such as in bright daylight. The shorter the duration of the flash the less light is transmitted, and the less intense will be the contrast surface image and it will be less distinct. However as the object is moving during the duration of the flash, a long duration flash will result in motion blur of the 'frozen' image, also making the image less distinct. It follows that depending on the brightness of the flash and the contrast of the image of the club head against the background there is an optimum duration of flash which results in an observable image of the club head. Lighting technologies currently exist which allow this invention to be practical, and a skilled addressee would be capable of determining the appropriate source for the desired embodiment. To enhance the images produced the following enhancements to the system may be employed.

• A high contrast tee area, for example a dark or black coloured 'tee ground' practice area so that the light coloured images of the golf club are easier to discern.

• Contrasting markings on the 'background' area which provide reference information. For example a circle the size of a golf ball to simulate an actual golf ball to the vision of the golfer. This gives the golfer a target when practising swinging without a golf ball. Also, lines in the tee area which can be used to provide the arc of an 'ideal' swing, or highlight the direction of an imaginary 'hole' . The golfer can compare the images produced by the invention against the lines to determine the accuracy of the direction and the alignment of the swing. Fine lines are less distracting for the user who is concentrating on seeing the contrast surface images. · A 'target' mark on the background. Either a circle as described in the previous paragraph to represent a golf ball, or any other mark which is observable to the user whilst not distracting from the stroboscopic images. The user can then aim to swing so that the golf club passes over the target. This will allow the user to assess the accuracy of the alignment of the swing.

• The contrast surface coating to be formed on the club head in lines or other geometric shapes. Lines and shapes more readily allow the orientation of the club to be ascertainable than if the whole of the club head were covered. For example these markings could be parallel or perpendicular to the club face. Parallel lines would allow the accuracy of the orientation of the club to be readily ascertained.

Perpendicular lines allow the direction and alignment of the swing to be readily visible. The contrast surface can be added to golf club, in particular the upper surface of the golf club or golf club substitute, during the process of manufacture. Alternatively, the contrast surface can be added retrospectively, for example, by a trained operative or a user. The contrast surface finish could be supplied in several forms including decals, tape or paint.

The contrast surface could contain a trademark or wording. Whilst this embodiment is clearly directed at golf clubs it will be appreciated that it could be used or any suitable sporting equipment, or indeed any activity where a component is required to be hit by human endeavour.

Claims

CLAIMS:

1. An apparatus for providing visible images of the position of a rapidly moving golf club or golf club substitute, wherein the apparatus comprises a golf club or golf club substitute and a stroboscopic light source, the golf club or golf club substitute includes a contrast surface, and wherein, in use, the stroboscopic light source is positioned to shine light on the contrast surface and the contrast surface is positioned to reflect the light to the golf club or golf club substitute user's eyes, and wherein the contrast surface is either (i) a retro-reflective surface or (ii) a surface having a higher reflectivity than the surface immediately surrounding the contrast surface.

2. An apparatus according to claim 1, wherein the contrast surface comprises one or more lines or geometric patterns.

3. An apparatus according to claim 1 or claim 2, wherein the contrast surface is adhered to the surface of the golf club or golf club substitute.

4. An apparatus according to claim 1 or claim 2, wherein the contrast surface is painted onto the surface of the golf club or golf club substitute.

5. An apparatus according to claim 1 or claim 2 , wherein the contrast surface is integrated into the golf club or golf club substitute.

6. An apparatus according to any one of the preceding claims, wherein the contrast surface is located on the head of the golf club or golf club substitute.

7. An apparatus according to any one of the preceding claims, wherein the contrast surface is located on an upper surface of the head of the golf club or golf club substitute.

8. An apparatus according to any one of the preceding claim, wherein a portion of the golf club or golf club substitute surrounding the contrast surface is coated in a dark coloured and/or low reflective surface.

9. An apparatus according to claim 8, wherein the contrast is positioned on the upper surface of the golf club head and the entire upper surface of the club head surrounding the contrast surface is coated in a dark coloured and/or low reflective surface.

10. An apparatus according to any one of the preceding claims, the apparatus further comprising a dark coloured and/or low reflective surface background for positioning beyond the contrast surface in line with the users' line of sight in use.

11. An apparatus according to claim 10, wherein the background is a dark coloured and/or low reflective surface coating or paint applied to a surface.

12. An apparatus according to claim 10 or claim 11, wherein the apparatus further comprises a dark coloured and/or low reflective mat as the background.

13. An apparatus according to any one of claims 10 to 12, wherein the background is marked with reference lines or geometric patterns.

14. An apparatus according to any one of the preceding claims, wherein the stroboscopic light is mounted on a unit to be worn about the head of a user.

15. An apparatus according to claim 14, wherein the stroboscopic light is mounted in the peak of a cap.

16. An apparatus according to any one of the preceding claims, wherein the contrast surface is a retro-reflective surface.

17. An apparatus according to any one of the preceding claims, wherein the contrast surface is a white surface and the area immediately surrounding the contrast surface is dark in colour.

18. A kit of parts comprising a stroboscopic light source and a contrast surface for applying to the head of a golf club or golf club substitute.

19. A kit of parts according to claim 18, wherein the kit further comprises a mat having contrast markings.

20. A method of showing the movement of a swinging golf club or golf club substitute, the method comprising the steps of: shining a stroboscopic light from a predetermined position so that the light shines substantially along the line of sight of a golf club or golf club substitute user, and swinging a golf club or golf club substitute with a contrast surface through the user's line of sight so that light from the stroboscopic light source reflects from the contrast surface towards the user's eyes.

21. A method according to claim 20, wherein the method includes the step of mounting the stroboscopic light source in the predetermined position so that the light shines substantially along the line of sight of a golf club or golf club substitute user.

22. A method according to claim 20 or claim 21, wherein the method includes the step of applying a contrast surface to the head of the golf club or golf club substitute.

23. Use of a stroboscopic light with a golf club or golf club substitute including a contrast surface, wherein the contrast surface is positioned on the golf club or golf club substitute to reflect light towards the golf club or golf club substitute user's eyes.

24. The use according to claim 23, wherein the contrast surface is on an upper surface of the head of the golf club or golf club substitute.

25. An apparatus, method, use or kit substantially as described hereinbefore with reference to the accompanying drawings.