GB2451234A

GB2451234A - Juggling equipment with computer controlled LED's

Info

Publication number: GB2451234A
Application number: GB0714302A
Authority: GB
Inventors: Oliver Simon Mylius
Original assignee: ALIX SHORT WILDING
Current assignee: ALIX SHORT WILDING
Priority date: 2007-07-23
Filing date: 2007-07-23
Publication date: 2009-01-28
Anticipated expiration: 2027-07-23
Also published as: FR2919197B1; FR2919197A1; GB0714302D0; DE202008009828U1; GB2451234B

Abstract

Juggling apparatus comprising a plurality of light sources arranged along its length, the states of which are sequenced by a control system to display, through persistence of vision effects, an image to an observer. The apparatus may include a number of battery powered multicoloured LED's which light in a pre-programmed sequence, and contained within a translucent body. The sequences may be pre-programmed into an apparatus memory or may be transmitted via a radio frequency to the apparatus.

Description

1 2451234

JUGGLING APPARATUS

FIELD OF INVENTION

The present invention relates to an apparatus, suitable for juggling, artistic twirling or spinning as a form of entertainment, which displays visual light-effects including repeating patterns, graphical images and alphanumeric text.

These visual effects are observed by the audience through retinal persistence and are the result of a plurality of light sources within the apparatus being made to switch on and off and change colour at precise timings by an incorporated control system.

BACKGROUND

The art of juggling frequently features objects (batons, clubs, staffs or p01) spinning through the air about an axis perpendicular to their longitudinal axis as they are either thrown or swung. The speed of this rotation is controlled by the performer and typically s between 1 and 4 revolutions per second.

Various improvements have been made to traditional designs of juggling apparatus in order to enhance the experience of the audience by making the manipulation more impressive. One such development which has become popular since the 1980s is to incorporate a light source (originally phosphorescent material and more recently, electrically powered light sources such as light emitting diodes) within the equipment (for example: Club for juggling with interior lighting': FR2716628), so that when juggled or manipulated in a darkened environment, retinal persistence effects create the illusion of a trail as the object moves through the air.

Persistence of vision (retinal persistence) refers to the apparent positive after-image when the human visual system is exposed to moving light sources, due to the fact that each retinal cell takes a few hundred milliseconds to return from its active state to a rest state. So when an object moves through an observer's field of vision, the observer's visual processing system will at any moment be exposed not only to the retinal signals relating to the object's current position within the field of vision, but also to a range of signals relating to the position of the object over the preceding few hundred milliseconds, these signals originating in retinal cells which are still in the process of returning to their rest state. It is the effect of these residual signals which gives the aforementioned illusion of an after-image behind a moving object. The effect is most apparent when the object is brightly illuminated, is moving quickly and the observer is in a darkened environment and therefore has heightened visual sensitivity.

Prior art includes juggling apparatus with two or three different coloured channels of light emitting diodes (for example one red channel, one blue channel and one green channel). By varying the intensity of the output of each channel, the overall perceived colour of the object could be made to change colour. Whilst visually effective from an audience point of view, this has the limitation that the entire object appears to be a single colour all over.

A further development positions the light sources in such a way that beams of different colours point towards one another inside a juggling object and graduated colour mixing occurs where the light falls on the surface of the object. In this way, some interesting abstract visual effects may be created. However images and graphics of a non-abstract nature have not been displayed by juggling apparatus

within prior art.

Persistence of vision effects have been incorporated in numerous other categories of devices in order to display a desired output -alphanumeric text, icons or other graphics. The general principle is to attach a row of light sources (often light emitting diodes) to an object which will be subject to motion. Each light source is switched on and off in a predefined sequence that is accurately timed to give the illusion of a pre-programmed output being displayed in the region of space over which the object was moved. (For example Display apparatus utilizing persistence of vision': US57481 57).

An extremely beneficial improvement to existing designs of juggling objects would be to incorporate a series of light sources that could take advantage of persistence of vision effects to display pre-programmed graphics or patterns whilst the juggler manipulates the object in performance. However there arises a difficulty because the juggler cannot ensure that a certain part of the object faces the audience whilst the object is in motion. Whilst the juggler has a great deal of control in spinning the object around the axis perpendicular to the longitudinal axis, it is impossible to control the spin about the longitudinal axis. The moment of inertia about this axis is relatively small and once released from the juggler's hands, the object will spin freely about this axis.

There is no existing persistence of vision device that can be juggled whilst displaying continuous graphics without large gaps or dark patches in the residual image observed by an audience. These gaps are caused by non-illuminated parts of the apparatus moving between the light sources and the observer due to the apparatus' spin around its longitudinal axis and are beyond the control of the juggler. Even persistence of vision devices where light sources are aimed backwards within the device as well as forwards, do not overcome this issue because the light sources are not clearly visible to an observer outside their angle of emission.

Previously described persistence of vision display devices incorporate motion detecting switches to control the frequency of output of light sources and hence the timing of the changes from one image being displayed to another. The effect of using this type of input system to control light sources in juggling and object manipulation apparatus would have severe shortcomings: By the nature of juggling, the apparatus moves rapidly but not always in a regular cycle of movements: A typical juggling performance will include a large number of different tricks being performed by the artiste. Some of these tricks will involve similar movements of the apparatus whilst others will involve very different movements. In addition, a trick may involve a juggler manipulating one object in a certain manner whilst simultaneously manipulating another or several other objects in a different manner. It would be desirable for the juggler to be able to select which pattern or graphic would be displayed by each apparatus at different moments throughout the performance independently of the type of motion that each item was describing at that moment.

STATEMENT OF INVENTION

An apparatus for juggling, artistic twirling or spinning, comprising a plurality of light sources arranged along its length, the states of which are sequenced by a control system to display, through persistence of vision effects, a graphical image to an observer when the apparatus is juggled or otherwise spun about a rotational axis that is perpendicular to its longitudinal axis.

The present invention relates to a juggling apparatus which is hereafter defined as an object suitable for manipulation within a juggling-related discipline and which is substantially stick-shaped or may comprise a substantially stick-shaped or tubular component, including but not limited to: Batons, Staffs, Poi (objects swung and twirled on the end of ropes), Juggling Clubs, Majorette-sticks, Martial-arts apparatus.

When in use, the present invention spins through the air about an axis that is perpendicular to its longitudinal axis and due to persistence of vision, the effect observed by an audience is that of a virtual image or graphic, made up of virtual pixels. The graphic may be an alphanumeric message, a repeating pattern or a number of individual logos or images Each virtual pixel is the result of light sources with one or more colour channels mounted inside the apparatus projecting light onto the internal surface of the apparatus. The outer material of the apparatus is translucent and therefore the projected light is visible to an observer. More than one region is illuminated simultaneously and the light is diffused by the translucent outer casing. The regions that are illuminated together with one another are located in parallel positions with respect to the length of the apparatus so that when the apparatus spins about the axis of rotation that is perpendicular to the longitudinal axis, all such regions pass through the same space. These regions cast diffused light in multiple directions so the displayed graphic is visible regardless of the phase of spin of the apparatus about its longitudinal axis at any moment. This is a considerable advantage of the present invention over prior art persistence of vision devices.

A control system is incorporated into the apparatus and determines the state of each light source at any moment. The control system comprises a microcontroller running an accurate sequencer program and a memory unit. A number of sequences of different graphics are encoded and stored in this memory unit. A highly accurate clock source such as a crystal oscillator may be incorporated into the control system so that graphics can be displayed according to an accurate time schedule. This permits a juggler to pre-program a performance so that certain images, patterns or messages are displayed at chosen timings within the performance in order to create an effect which is most complimentary to the backing music or to the structure of the performance.

The present invention includes a communication interface which may be wired or wireless so that signals from an external source may be received and processed by the control system within the apparatus. The communication system is multipoint so that a computer or remote control unit is able to transmit control instructions to more than one juggling apparatus simultaneously. In this way a plurality of the present invention can be triggered to begin a sequence at the same moment and subsequently therefore display synchronized graphics or text-based messages. At least two items of juggling apparatus are used simultaneously by a juggler, and in some cases this number can be much higher: it is not uncommon to see solo jugglers manipulating five clubs or juggling troupes with several jugglers using a number of apparatus simultaneously. The effect to an observer of several apparatus changing display at exactly the same moment, without the jugglers interrupting the flow of their manipulation, is clearly very impressive.

The control system receives information via the communication interface for the following processes: -Selecting which sequence of pre-programmed graphics will be displayed and triggering the apparatus to begin displaying that sequence -Uploading a new sequence of graphics to storage memory in the apparatus -Operational controls, for example to put the apparatus into or wake it from a low power standby mode By using a wireless communication interface, the control system may process instructions in real time and receive data describing the colours that the light sources should output to display graphics, whilst the apparatus is in use. One advantage of this system is that the displayed output of the apparatus may be controlled by a third party, allowing performance and visual effects to be improvised: Whilst the juggler is on stage, an accomplice is constantly selecting graphics to be displayed on the basis of the flow of the music, the audience reactions or even in response to the tricks being selected by the juggler.

The present invention may use Electronically Erasable Programmable Read-Only-Memory or flash memory that can be easily removed from the apparatus by a user in order to program data describing graphics. Secure Digital (SD), MMC, XD, USB flash memory and other such formats are all functionally equivalent for this purpose and offer the advantage of extremely high capacity, and widespread compatibility with computers via readily available memory card readers and USB adapters. A further advantage is that the microcontroller does not need to handle communication with a computer as all programming of graphic data is done directly from the computer to the memory card before the card is slotted into the apparatus.

The present invention offers the advantage of being able to display graphics that fill almost the entire area through which the apparatus moves in use, whilst keeping the number of light sources to a minimum and thus avoiding problems associated with increases in power consumption; higher manufacturing costs due to increased component count and increased overall weight which could potentially render the apparatus prohibitively difficult to manipulate by the juggler. This is achieved by projecting light onto regions of the apparatus' interior surface so as to illuminate an area of the exterior surface that appears much larger than a single point light source.

The light sources are spaced along the length of the apparatus without there being gaps between the illuminated regions of the exterior surface, which would otherwise produce dark stripes in the residual image that is displayed.

Complex multi-coloured images and graphics may be displayed when the apparatus is in use by using light sources of more than one colour. These output colours may be mixed in varying proportions either by pulse width modulation of each colour channel or by varying the electrical current through each colour channel, allowing each of the defined regions on the visible exterior surface of the object to be specified as any one of a number of possible colours.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a general illustration of a juggling apparatus according to the present invention showing a residual image created by the apparatus in use.

Figure 2 is a cross section of a juggling apparatus according to the present invention.

Figure 3 is a schematic showing the electronic circuit inside the apparatus.

Figure 4 shows four different embodiments of the invention including their axes of rotation, in which: Figure 4a shows the present invention in the embodiment of a poi.

Figure 4b shows the present invention in the embodiment of a juggling staff.

Figure 4c shows the present invention in the embodiment of a swinging baton.

Figure 4d shows the present invention in the embodiment of a juggling club.

Figure 5 shows the illuminated regions of the exterior surface of the apparatus in two alignments, in which: Figure 5a shows the apparatus aligned so as to point light sources directly towards the viewing angle.

Figure 5b shows the apparatus aligned so as to point light sources perpendicular to the viewing angle.

Figure 6 shows the optimal spacing of light sources so that illuminated regions do not have gaps between them nor do they overlap with one another.

Figure 7 is a flow chart describing the program running on the microcontroller in the apparatus.

Figure 8 is a diagram illustrating two different embodiments using different communication interfaces in which: Figure 8a shows the present invention with a wired communication interface.

Figure 8b shows the present invention with a wireless communication interface.

Figure 9 is a schematic showing an embodiment comprising a plurality of microcontrollers operating in parallel.

Figure 10 shows the apparatus in use, having been programmed to display alphanumeric characters.

LIST OF REFERENCE NUMERALS

I Residual image as seen by observer 2 Direction of rotation of apparatus 3 Translucent outer casing 4 Illuminated region of surface: Colour 1 Illuminated region of surface: Colour 2 6 Illuminated region of surface: Colour 3 7 Handle 8 Battery 9 Microcontroller Light source 11 Light source: Colour 1. (11 a and 11 b are two light sources of the same colour aimed in different directions) 12 Dashed lines show angle of emission of light 13 End-cap 14 Socket Storage memory 16 Light source: Colour 2 17 Light source: Colour 3 18 Box shows all light sources comprising Virtual Pixel 1 19 Box shows all light sources comprising Virtual Pixel 2 Box shows all light sources comprising Virtual Pixel 3 21 Box shows all light sources comprising Virtual Pixel n 22 Longitudinal axis 23 Axis of rotation that is perpendicular to longitudinal axis 24 Knob Angle of emission 26 Surface of outer casing 27 Remote control unit 28 Cable 29 Plug inserted into socket in apparatus Plug connecting cable to remote control unit 31 RE receiver and antenna in apparatus 32 Laptop computer 33 RF transmitter and antenna in laptop computer 34 Current source Master microcontroller 36 Slave microcontroller 37 Clock source 38 Virtual pixel 39 Centre of circuit board Boundary between two adjacent illuminated regions 41 Bulb of juggling club

DESCRIPTION OF INVENTION

Figure 1 shows the invention in use. The embodiment shown is that of a p01 (a juggling apparatus with a handle (7) attached by string/rope which is spun by the juggler holding the handle). The figure also shows a residual image (1) that is observed by an audience when the apparatus is spun in the direction shown by the arrow (2). (The grid lines in the figure would not be visible in reality but have been included for the purpose of illustration). Each pixel (38) of the image is the result of one group of parallel light sources being actuated to appear a certain colour for the amount of time it takes for those light sources to move through that region of the observer's field of vision. The residual image is displayed clearly, even when the apparatus rotates arbitrarily about its longitudinal axis, due to the multiple parallel light sources as shall be explained below, with reference to figures 5a and 5b.

The invention comprises an outer casing (3) made of a translucent material resilient enough to withstand impact forces caused by collisions with other apparatus in normal use. In several embodiments (Figures 4a, 4b, 4c), this outer casing is substantially a tube which has been adapted by attaching handles (7), knobs (24), end caps (13) and supplementary weighting in order to make it suitable for juggling.

An alternative embodiment is shown in Figure 4d where the outer case comprises a moulded plastic bulb (41) and a handle (7), assembled to form a substantially club-shaped object.

The cross section of the apparatus in figure 2 shows an electrical circuit mounted inside the outer casing. The circuit comprises a microcontroller (9), outputs of which are connected to light sources (10) which are preferably multi-coloured light emitting diodes, each one comprising a red emitter, a green emitter and a blue emitter within one package (hereafter referred to as RGB LED). A battery (8) is securely mounted within the apparatus and connected to the circuit in such a way as to power the microcontroller and the light sources.

The circuit comprises a reprogrammable storage memory unit (15) which is preferably one or more EEPROM (Electrically Erasable Programmable Read-Only-Memory) chips, the contents of which are readable and writable by the microcontroller. This memory is used to store data which is accessible by the microcontroller and may be translated into different configurations of outputs in order to create different graphical images. As an alternative to, or in addition to an external EEPROM chip, the invention may use flash or EEPROM memory that is built into the microcontroller.

The circuit also comprises a communication interface, which in a preferred embodiment is an electrical socket (14) mounted in the exterior casing of the apparatus. The terminals of this socket are connected to input and output pins of the microcontroller. Cables (28) can be connected by a user between a plurality of apparatus and an external source such as a computer or a remote control unit (27) as shown in figure 8a. Whilst connected, the user is able to send control signals to the apparatus or to reprogram the storage memory. Once the communication has been completed, the user unplugs the cable (28) before juggling with the apparatus.

Various protocols are suitable for this type of communication, including but not limited to RS485 and Universal Serial Bus.

An alternative embodiment uses a wireless communication protocol so that the apparatus may receive control signals or be reprogrammed with new data describing graphics and sequences of graphics without the need to plug a wire into the apparatus. Such an embodiment comprises a radio frequency receiver and antenna mounted within the apparatus (31) and connected to the microcontroller. A separate transmitter unit (33) is used to transmit control signals or data encoding the desired output of the light sources from an external source to the apparatus. The transmitter may be connected a computer (32) or it may part of a dedicated remote control unit.

Various wireless radio protocols are suitable for this purpose including but not limited to Bluetooth (point-to-multipoint connection) and serial communication via AM or FM radio. Figure 8b shows two swinging batons according to the present invention, each comprising a RF receiver and antenna which receives signals from a laptop computer that has an integrated radio transmitter.

The schematic in figure 3 shows how the microcontroller (9) is connected to the memory (15), the communication socket (14) and the light sources (ha, 1 Ib, 16, 17) which are mounted in groups (18, 19, 20, 21) so as to form each virtual pixel. Current sources (34) are employed to drive the LEDs. In the preferred embodiment, as shown, all the Red emitters (ha and lib) in one virtual pixel are connected in series to one current source, which is connected to one microcontroller output pin. Similarly, all Green emitters (16) in one virtual pixel are connected in series to a second current source, which is connected to a second microcontroller output pin, and so on for the Blue emitters of that virtual pixel and then for each emitter of the other virtual pixels. The clock source (37) is preferably a crystal oscillator and is employed to ensure accurate timings of output sequences.

Although the preferred embodiment uses single package RGB LEDs as the light sources, separate single-coloured LEDs may be used instead. In this case, the LEDs are mounted in clusters, each cluster containing at least one LED of each colour, and each LED in a cluster aiming at the same region of the surface of the apparatus.

The light sources are mounted in such a way that each one projects light onto a region of the interior surface of the tube and owing to the translucency of the surface, this light is visible from the outside of the tube as a diffused region of illuminated colour (4) whilst the point light source itself is not visible. Light sources are mounted in parallel positions (where parallel means equidistant from one end of the apparatus) in order to project light onto parallel regions of the interior surface of the tube. In a preferred embodiment as shown in figure 2, one RGB LED (ha) is mounted on one surface of a circuit board at an angle perpendicular to the surface of the circuit board, whilst another RGB LED (11 b) is mounted on the opposite surface of the circuit board at an angle perpendicular to the surface of the board. These two LEDs therefore point in opposite directions but are always actuated simultaneously.

Thus when one region is made to appear a certain colour by the light emitting diodes projecting light onto it, the other illuminated regions that are parallel to the first region are also made to appear the same colour. For example in Figure 4a, the two regions labelled (4) will always be the same colour as each other, and when the apparatus is in use, these two regions together will form one virtual pixel. Similarly, the two regions labelled (5) will always be the same colour as each other, and will together form a second virtual pixel.

An alternative embodiment comprises side-emitting light sources which have optical characteristics whereby the majority of the light is emitted at an angle of approximately 80 degrees from the surface normal. These side emitting light sources are mounted in alignment with the length of the apparatus so that light emitted from their sides illuminates a larger area of the apparatus' surface than light from a single regular light source mounted as in figure 2 would do. This offers the advantage of lower component count, reduced power consumption and increased apparent brightness of the residual image.

In figures 4a, 4b, 4c and 4d, the dashed lines show the longitudinal axis of rotation (22) and the perpendicular axis (23) about which the juggler intentionally spins the apparatus. Figure 4a shows the invention in the embodiment of a poi which is spun by a handle that is attached to the apparatus by string, rope or cable. Figure 4b shows the invention in the embodiment of a juggling staff which is centrally balanced and rotated around its central point and figure 4c shows the invention in the embodiment of a swinging baton which is swung by a knob (24) at its end. Figure 4d shows a juggling club comprising a handle which is conical or cylindrical with a diameter not exceeding 40mm. The juggling club spins in the air about a perpendicular axis passing through its centre of gravity when thrown but may also be swung by the knob which is fixed to the end of its handle. The illustrated embodiment of the juggling club in figure 4d has groups of four parallel light sources (5) of each colour for each virtual pixel in the bulb end (41): In the illustration, for each virtual pixel, one light source is directed directly towards the point of view of the drawing; a second is directed upwards; a third is directed downwards and the fourth is directed backwards, away from the point of view of the drawing, and therefore is not visible in the illustration.

Figures 5a and 5b show the invention in two different phases of rotation -5a is from the point of view of an observer when one surface of the circuit board is pointing directly towards the observer and so the illuminated regions forming each virtual pixel directly face the observer. In figure 5b, the apparatus has rotated through 90 degrees on its longitudinal axis, so that the LEDs are now pointing at an angle perpendicular to the viewing angle and the illuminated regions forming the virtual pixels no longer face the observer directly. In both of these orientations, and indeed any other orientation of the apparatus about its longitudinal axis, sufficient illuminated regions of the apparatus' surface forming each virtual pixel are clearly visible to an observer and thus the residual image is still clearly visible to the observer.

The resolution of the virtual image is defined by three factors: -The size and number of illuminated regions along the length of the apparatus.

-The frequency at which the control system refreshes the virtual pixels -The speed of rotation of the object when spun by the juggler. The faster the object spins, the larger each virtual pixel will appear to an audience because the object will have covered a larger distance within the time-unit that one pixel is displayed for.

The distance between each parallel group of light sources is critical to ensure that the apparatus can display images and graphics clearly. If the light sources are spaced too closely together, then light from one source will overlap with light from an adjacent source. The result would be a blurred region of mixed colour between the virtual pixels in the residual image, and hence sharp images could not be displayed.

If the light sources are spaced too far apart, then there will be gaps between adjacent illuminated regions, which will appear as dark stripes when the object is in use. T he optimal arrangement is shown in figure 6. There is no gap between the two adjacent illuminated regions, nor do they overlap at the boundary (40). The distance (d) between the light sources is dependent on the inside radius of the tube (r), the height of the emitter (h) above the centre of the tube (39), and the angle of emission (a) of the light emitting diode, and is defined by the following formula: d = 2(r-h) x Tan (af2) where: d = distance between LED5 r = inside radius of tube h = height of emitter above centre of circuit board a = angle of emission of LED An alternative embodiment comprises opaque barriers mounted within the apparatus to prevent the light emitted by one source overlapping with light emitted from a neighbouring source on the surface of the apparatus, allowing the light sources to be positioned more closely together without blurring the edges between virtual pixels.

The microcontroller runs a program as outlined in the flow chart of figure 7: The communication interface is monitored and if data that describes graphics (patterns, images, text etc.) is received then this data is stored in the EEPROM memory. If a Trigger' control signal is received by the microprocessor then it proceeds to display a sequence of graphics as described below. Otherwise, the microcontroller continues to monitor input (Standby mode loop).

Once triggered, the microcontroller initializes its internal timers and the registers relating to EEPROM locations of graphic data. The microcontroller retrieves data refernng to a row of pixels from EEPROM then enters a loop where it displays this row of pixels by configuring the output pins that are connected to the LEDs.

During the time interval when the current row of pixels is displayed, the microcontroller loops through a pulse-width modulation (PWM) routine. It actuates each of the component colours (red/green/blue in the case of the preferred embodiment) of each virtual pixel for a proportion of the time interval determined by the required intensity of that colour component. In this way a range of colours can be specified for each virtual pixel.

Once the time interval has expired, the next row of pixels is displayed. Each recursion of this loop, the microcontroller checks the timer. If the current time unit is up, then it wdl retrieve the data for the next row of pixels, and continue to loop as previously described, having first established that it is not the end of the sequence.

If it is the end of the sequence, then the microcontroller checks a register which defines whether this sequence should be displayed once only in which case it will turn all the LEDs off and enter a low power state. Alternatively, the microcontroller continues to display the sequence indefinitely by reinitializing the timers and EEPROM locations and looping through the entire sequence again.

A computer application is used to take as input an on-screen representation of a graphic in grid form where each square represents a virtual pixel. The application translates the content of the grid into the data structure used by the microcontroller. It is then transmitted via the communication interface to the microcontroller which writes the data to storage memory.

Data describing separate sequences of graphics may be stored in different memory locations. The user selects which of the stored sequences to activate by transmitting one particular Trigger' control signal, where the other possible Trigger' control signals refer to alternative sequences of graphics.

A further embodiment comprises a socket that is accessible to users for inserting flash based memory card. The terminals of this socket are connected to the microcontroller which is programmed to read graphic data from the flash based memory. When a user chooses to program new graphics, they remove the flash memory from the apparatus and connect it directly to a computer. Once the data has been written from the computer to the apparatus, the memory is reinserted into the apparatus.

Although the above description uses pulse width modulation to display differing intensities of each colour channel, differing intensities may also be displayed by adjusting the current driving the light sources in each colour channel of each virtual pixel. In this case, the data that is stored in memory, referring to each virtual pixel, encodes the configuration of microcontroller's outputs which are connected as illustrated in figure 3 to current sources (34) with a range of output currents.

A further embodiment permits a single instance of a repeatable graphic to be encoded at a specified memory location in the storage memory. The microcontroller, using the address of that memory location, retrieves the data describing that one graphic, and then loops the display of that graphic. In this way, the available memory capacity is used efficiently because data which will be repeated need only be encoded once and as such, a large number of graphics may be encoded including full alphanumeric typefaces. The program running on the microcontroller may include a sequencer which displays previously selected graphics at particular times. The data describing these timings and the list of corresponding memory locations for graphics which will be displayed at each time may also be encoded in the storage memory. As the memory is rewritable via the communication interface, new sequences may be uploaded to the apparatus as the user wishes. Text based messages may be encoded in the memory as a sequential string of values where each value can be translated by the microprocessor into the memory location of the full data describing one alphanumeric character.

Figure 10 shows the apparatus having been programmed to display an alphanumeric message. Graphics that must be displayed in the correct orientation, such as text, may be stored twice in the memory: once in forward' orientation and once inverted.

The juggler selects which version to include in their sequence depending on the direction of rotation of the apparatus (clockwise or anti-clockwise) from the audience viewpoint. The direction of rotation is determined by which way the juggler is facing and which tricks or patterns he/she is performing at the time.

Another embodiment illustrated by the schematic in figure 9 comprises a plurality of microcontrollers (36) operating in parallel. Each microcontroller determines the state of a subset of the light sources. Each microcontroller may be connected to an individual EEPROM memory. The advantage of this embodiment is that each microcontroller processes a lesser amount of information and thus is able to refresh the states of the virtual pixels at a greater frequency, resulting in a higher resolution graphic. Furthermore the number of possible virtual pixels is no longer limited by the number of available output pins from a single microcontroller. Further groups of light sources may be added, each group being connected to another microcontroller with the maximum number being limited only by the current that can be supplied by the battery. To ensure that all the microcontrollers are accurately synchronized, a common external clock source may be shared and connected to all the microcontrollers. As shown in figure 9, a master/slave arrangement may be implemented where one microcontroller assumes the role of master' (35) and handles the timings of the sequence. This microcontroller then communicates to the slave' microcontrollers (36) whenever a time unit has expired and it is time to display the next column of virtual pixels in the graphic. Communication between the microcontrollers may use Serial Peripheral Interface Bus (SPI), Inter-Integrated Circuit (12C) or a proprietary protocol.

Claims

CLAIMS 1. An apparatus for juggling, artistic twirling or spinning, comprising a plurality of light sources arranged along its length, the states of which are sequenced by a control system to display, through persistence of vision effects, a graphical image to an observer when the apparatus is juggled or otherwise spun about a rotational axis that is perpendicular to its longitudinal axis. 2. An apparatus according to claim 1 in which light sources are arranged in groups of two or more, each light source within the group being controlled so as to always be in the same state of illumination as the others within the group, and positioned in close proximity to the others within the group yet aimed in a different direction from others within the group so that light from at least one source within the group is visible from any viewing angle regardless of the phase of rotation of the apparatus about its longitudinal axis. 3. An apparatus according to claim I in which the outer casing is translucent and regions of the apparatus' exterior surface are illuminated by light sources inside the apparatus. 4. An apparatus according to claim 1 in which the control system comprises one or more microcontrollers, the outputs of which are connected to light sources such that the output of the light sources is determined by the execution of program instructions running on the microcontroller or microcontrollers. 5. An apparatus according to claim 4, comprising storage memory, such that the data stored in the memory is accessible to a microcontroller and encodes different configurations of illumination of the light sources. 6. An apparatus according to claim I wherein one region of the apparatus' exterior surface is illuminated by sources of more than one colour of light. 7. An apparatus according to claim I wherein the apparent intensity of each light source is controlled by pulse width modulation, the duty cycle being determined by a value retrieved from the memory unit. 8. An apparatus according to claim 4 wherein the current driving a light source is varied, according to a value retrieved from memory, by changing the configuration of microcontroller outputs that are connected to a current source. 9. An apparatus according to claim 4, comprising a radio frequency receiver to convey signals from an external source to a microcontroller within the apparatus. 10.An apparatus according to claim 4, comprising a wired communication interface to convey signals from an external source to a microcontroller within the apparatus through a cable. 11.An apparatus according to claim 9 or claim 10 where the communication protocol used to convey signals is multipoint for synchronising graphical displays with other apparatus. 12.An apparatus according to claim I such that the light sources and control system are powered by a battery. 13.An apparatus according to claim 3 in which light sources illuminating regions of the exterior surface of the apparatus that are parallel with respect to the apparatus' length are actuated simultaneously and in the same colour so that residual images are displayed by the apparatus in motion. apparatus' length are actuated simultaneously and in the same colour so that residual images are displayed by the apparatus in motion. 14.An apparatus according to claim 1, comprising opaque barriers between light sources to prevent light emitted by one source overlapping with light emitted from a neighbouring source on the surface of the apparatus. 15.An apparatus according to claim 5 in which data describing a repeatable output graphic is stored in the memory and the microcontroller is programmed to retrieve and loop the display of a sequence of graphics according to a timing schedule which is also encoded in memory. 16.An apparatus according to claim 9 in which the displayed output graphics are determined by an external source and communicated to the apparatus by radio frequency whilst the apparatus is being manipulated by the user. 17.An apparatus according to claim 4 further comprising an accurate clock source connected to a microcontroller for the display of accurately timed sequences of graphics.

1 8.An apparatus according to claim I in which the outer casing is substantially tubular and which is centrally balanced.

19.An apparatus according to claim 1 in which the outer casing is substantially tubular and which has a knob fixed to one or both ends.

20.An apparatus according to claim 1 whose outer casing comprises one handle component that is substantially cylindrical or conical with a diameter of less than 40mm and with a knob fixed to its extremity.

21.An apparatus according to claim 1 in which the outer casing is substantially tubular and which has a handle attached by a rope, string or cable to one end.

22.An apparatus according to claim 4 comprising a socket for removable flash based memory to be inserted.

23.An apparatus according to claim I comprising light sources with side-emitting characteristics.

Amendments to the claims have been filed as follows 1. A juggling or handheld artistic twirling apparatus, comprising an elongate body having a plurality light sources arranged along its length, and a control system for sequencing the intensity states of the light sources to display, through persistence of vision effects, a non-abstract graphical image to an observer when the apparatus is juggled or twirled about a rotational axis that is perpendicular to its longitudinal axis, wherein the light sources are arranged in a plurality of groups, each group containing two or more light sources positioned equidistant from the same end of the apparatus, and each light source being positioned in close proximity to the others within the group yet aimed in a different direction from the others within the group so that light from at least one light source within the group is visible to the observer regardless of the phase of rotation of the apparatus about its longitudinal axis, and wherein the control system is arranged to control the light sources so that the light sources within the same group are always in the same state of illumination as each other.

2. An apparatus according to claim 1, having a translucent outer casing and wherein the light sources are arranged inside the apparatus to illuminate regions of the casing's surface.

3. An apparatus according to claim 1, in which the control system comprises one or more microcontrollers, the outputs of which are connected to the light sources such that the output of the light sources is determined by the execution of program instructions running on the microcontroller or microcontrollers.

4. An apparatus according to claim 3, further comprising storage memory, such that data encoding different configurations of illumination of the light sources stored in the memory is accessible to a said microcontroller.

5. An apparatus according to claim 1, wherein light sources of more than one colour of light are arranged to illuminate one region of the apparatus' exterior surface.

6. An apparatus according to claim 1, wherein the apparatus is arranged to control the apparent intensity of each light source by pulse width modulation, the duty cycle being determined by a value retrieved from a memory unit.

7. An apparatus according to claim 3, wherein the apparatus is arranged to vary the current driving a light source according to a value retrieved from memory by changing the configuration of the microcontroller outputs that are connected to a current source.

8. An apparatus according to claim 3, further comprising a radio frequency receiver to convey signals from an external source to a said microcontroller within the apparatus.

9. An apparatus according to claim 3, further comprising a wired communication interface to convey signals from an external source to a said microcontroller within the apparatus through a cable.

10. An apparatus according to claim 8 or claim 9, where the communication protocol used to convey signals is multipoint for synchronising graphical displays with other apparatus.

11. An apparatus according to claim 1, wherein the light sources and control system are powered by a battery.

12. An apparatus according to claim 1, further comprising opaque barriers between each group of light sources, wherein said barriers are arranged to prevent light emitted by a light source overlapping with light emitted from a light source in a neighbouring group on the surface of the apparatus.

13. An apparatus according to claim 4, in which data describing a repeatable output graphic is stored in the memory and the microcontroller is programmed to retrieve and loop the display of a sequence of graphics according to a timing schedule which is also encoded in memory.

14. An apparatus according to claim 8, further comprising an external source for communicating output graphics to be displayed to the apparatus whilst the apparatus is being manipulated by a user.

15. An apparatus according to claim 3, further comprising a clock source connected to a microcontroller for the display of timed sequences of graphics.

16. An apparatus according to claim 1, having a substantially tubular outer casing and which is centrally balanced.

17. An apparatus according to claim 1, having a substantially tubular outer casing and which has a knob fixed to one or both ends.

18. An apparatus according to claim 1, having an outer casing with one handle component that is substantially cylindrical or conical with a diameter of less than 40mm and with a knob fixed to its extremity.

19. An apparatus according to claim 1, having an outer casing that is substantially tubular and which has a handle attached by a rope, string or cable to one end.

20. An apparatus according to claim 3, further comprising a socket for removable flash based memory to be inserted.

21. An apparatus according to Claim 1, wherein the light sources have side-emitting characteristics. fl

22. An apparatus according to Claim 1, further comprising a memory unit for storing a plurality of sequences of different graphics for display as graphical images by the apparatus, and wherein the control system includes a sequencer program for displaying the graphics according to a time schedule as the apparatus is manipulated by a user.

23. An apparatus according to claim 13, 14 or 22, wherein each graphic is stored twice, once in a forward direction and once inverted, for selection by the user depending on the direction of rotation of the apparatus.

24. An apparatus according to claim 3, wherein the control system comprises a plurality of microcontrollers arranged to operate in parallel, each of the microcontrollers being arranged to determine the intensity state of each light source in a respective subset of the light sources.

25. An apparatus according to claim 24, further comprising a clock source for each of the microcontrollers to synchronise the microcontrollers.

26. An apparatus according to claim 24, wherein each of the microcontrollers is arranged as a slave microcontroller, and the apparatus further comprises a master microcontroller arranged to communicate timing information to the slave microcontrollers.

27. A system comprising: a plurality of apparatus according to claim 8 or claim 9; and a control unit for transmitting signals to more than one of said apparatus so as to trigger those apparatus to begin a display sequence at the same time.

28. A juggling or handheld artistic twirling apparatus, substantially as described herein with reference to, or substantially as shown in, the accompanying drawings.