VISUAL DISPLAY SYSTEMS

SYSTEME D'AFFICHAGE

English Abstract

A bicycle wheel (4) is supported by a fork (6) to which a magnet (12) is
attached. Attached to one spoke (8) of the wheel (4) is an
elongate array (10) comprising sixteen light emitting diodes extending
radially of the wheel (4). A controller (16), mounted on the spoke
(8) is connected to the array (10) by a cable (18). The controller includes a
memory that stores a program for controlling the sequence in
which the different LEDs of the array are to be energised. By selecting the
timing and energisation of the different LEDs in accordance
with a predetermined program, the observer will see an apparently stationary
image on the wheel notwithstanding that it is rotating.

French Abstract

La présente invention concerne une roue (4) de bicyclette soutenue par une fourche (6) à laquelle on a fixé un aimant. Un ensemble (10) allongé, fixé à un rayon (8) de la roue, comprend seize diodes électroluminescentes DEL qui s'étendent radialement par rapport à la roue (4). Un dispositif de commande (16), monté sur le rayon (8), est connecté à l'ensemble (10) par un câble (18). Ledit dispositif de commande (16) comprend une mémoire qui stocke un programme destiné à commander la séquence selon laquelle les différentes DEL de l'ensemble sont alimentées en courant. En sélectionnant le temps et l'alimentation en courant des différentes DEL, conformément à un programme déterminé, l'observateur voit une image apparemment fixe sur la roue indépendamment du fait qu'elle tourne.

Claims

6
What is claimed is:
1. A display system for a rotary wheel mounted for rotation about an axis
inclined to the direction of the gravitational field, the system comprising:
an elongate array of light emitting devices to be mounted on the wheel
extending in a radial direction,
a controller to be mounted on the wheel and connected to the light emitting
devices for controlling the energisation of the light emitting devices in a
sequence in
accordance with a program stored in a memory of the controller,
an accelerometer to be mounted on the wheel spaced from the axis of the
wheel to provide an output indicative of the speed and angular position of the
wheel,
and
control means responsive, each time said output indicates that a predetermined
angular position has been reached to initiate an energising cycle for the
array of light
emitting devices by the controller at instants in the cycle determined in
accordance
with the program stored in the memory, the control means varying a rate of
energisation in accordance with the speed of the wheel whereby to provide an
apparently stationary image on the wheel corresponding to the program stored.
2. A display system according to claim 1, wherein the memory is
reprogrammable to store data representing different images.
3. A system according to claim 1 or claim 2, wherein said light emitting
devices
comprise light emitting diodes.
4. A system according to any one of claims 1 to 3, wherein the control means
inhibits operation of the controller until it senses that the rotary speed of
the wheel has
reached a predetermined rate.
5. A system according to any one of claims 1 to 4, wherein the wheel is a
bicycle
wheel and the array, the controller, the accelerometer and the control means
are all
mounted on a common spoke of the wheel.
6. A system according to any one of claims 1 to 5, wherein the control means
comprises two parts, a first part secured to the rotary wheel and a second
part

7
containing the memory, the second part being detachable from the first part
and
connectable to a computer for reprogramming.
7. A system according to claim 6, wherein the second part contains a power
source for the system.

Description

CA 02295768 1999-12-21
' ' EPO - DG 1
01. 06. 1999
-1- 78
VISUAL DISPLAY SYSTEMS
The present invention relates to visual display systems.
The wheels of bicycles are often decorated with material which gives a
pleasing effect to a remote viewer. However, because the wheel rotates and
rotates at
different speeds little more than a blur of colour is usually observable.
It is an object of the invention to provide a display system which enables the
viewer to view a distinct, apparently stationary, image of alphanumeric
characters and/or
other material on the rotating member such as the wheel of a bicycle or other
vehicle.
According to the present invention there is provided a display system for a
rotary wheel comprising an elongate array of light emitting devices to be
mounted on the
wheel extending in a radial direction, a controller to be mounted on the wheel
and
connected to the light emitting devices for controlling the energisation of
the light emitting
devices in a sequence in accordance with a program stored in a memory of the
controller,
an accelermeter to be mounted on the wheel spaced from the axis of the wheel
to sense the
rotary position of the wheel, and control means responsive to the accelermeter
to initiate an
energising cycle for the light emitting devices by the controller at positions
determined in
accordance with the program stored in the memory, the control means varying
the rate of
energisation in accordance with the speed of the wheel whereby to provide an
apparently
stationary image on the wheel corresponding to the program stored.
According to the present invention there is further provided a display system
for a rotary member comprising an array of light emitting devices to be
mounted on the
member, a controller to be mounted on the member and connected to the light
emitting
devices for controlling the energisation of the light emitting devices in a
sequence in
accordance with a program stored in a memory of the controller, a sensor to be
mounted on
the member to sense the passage of the member past a locator rigid with a non-
rotary
support for the member, and control means responsive to the sensor sensing the
locator to
~'p~~P~~' SHEc

CA 02295768 1999-12-21
-2-
initiate an energising cycle for the light emitting devices by the controller
in accordance
with the program stored in the memory, the control means establishing a datum
position of
the member at which the energisation cycle can be initiated and varying the
rate of
energisation in accordance with the speed of the member whereby to provide an
apparently
stationary image on the member corresponding to the program stored, the memory
being
reprogrammable to store data representing different images.
A bicycle having a visual display system, embodying the present invention,
will now be described by way of example, with reference to the accompanying
diagrammatic drawings, in which:
Figure 1 is a perspective view of the bicycle displaying an advertising trade
mark;
Figure 2 is a fragmentary view of the front wheel of the bicycle
incorporating the display system; and
Figure 3 is a block diagram of the display system in conjunction with a
system for reprogramming the display system.
Figure 1 shows a bicycle 2 having a front wheel 4 carrying an illuminated
image of the registered trade mark REEBOK which, to the stationary observer,
appears
stationary on the bicycle notwithstanding that the wheel 4 is rotating.
As shown in Figure 2, the wheel 4 is supported by a fork 6 to which a
locator in the form of a magnet 12 is attached. Attached to one spoke 8 of the
wheel 4 is an
elongate array 10 comprising sixteen light emitting diodes (LEDs) extending
radially of the
wheel 4. Also mounted on the same spoke 8 is a controller 16, which includes a
battery
(not shown), and is connected to the array 10 by a cable 18. The imbalance
caused by the
attachments to the wheel can be corrected by the use of counterweights (not
shown)
attached to the diametrically opposite side of the wheel.
The controller includes a memory (not shown) that stores a program for
controlling the sequence in which the different LEDs of the array are to be
energised. By

CA 02295768 1999-12-21
WO 98/59333 PCT/GB98/01794
-3-
selecting the timing and energisation of the different LEDs in accordance with
a
predetermined program, the observer will see an apparently stationary image on
the wheel
notwithstanding that it is rotating.
The effect is achieved because with light flashes of very short duration, the
reaction of the human eye to the flash persists long after the flash has
finished. Thus, where
a series of very short flashes occur over a short time span less than 0.01 S
seconds, all the
flashes appear to the eye to have occurred at the same time and when the
flashes are spaced
from one another on the retina because the array has moved relative to the
retina, the eye
perceives a composite light pattern which will persist for a short while
immediately
following the time span. It will thus be appreciated that a program can be
created and
stored in the memory which will produce almost any desired image for the
observer. The
image may take the form of alphanumeric information or may take the form of an
advertising poster.
In order for the viewed display to start at a particular angular location on
the
wheel and to prevent drift due to a change in speed of the wheel, the rotation
of the wheel
has to be sensed. A sensor in the form of a magnetic reed relay 14 is mounted
on the spoke
8 and this is triggered each time the sensor 14 passes the locator magnet 12.
Control means
(not shown) within the controller 16 responds to the operation of the reed
switch to initiate
the readout from the memory at the same angular position of the spoke 8 during
each full
cycle of rotation of the spoke.
Thus, the start point of the image will always be in the same position. The
control means also measures the repetition rate of the operation of the switch
14 and
inhibits a readout from the memory until the speed of the wheel reaches 3
Srpm. After this
point has been reached, the control means controls the readout rate from the
memory to the
array directly in proportion to the instantaneous repetition rate determined
by the control
means.

CA 02295768 2005-12-07
4
The block diagram of Figure 3 shows how the memory of the controller 16 can
be programmed. As shown, a desired image is created with the aid of an IBM* PC
compatible computer 20 and configured as a 200 x 16 pixel array. The array is
downloaded into a programmer 22 which converts the driving data stream into a
processor compatible processing stream. The processor in turns loads the
program for
the array into the memory of the controller or electronics 16.
It will be appreciated that instead of a battery, power can be induced into
the
controller from a rotary part of the bicycle using an induction system.
As an alternative, power can be fed from a source mounted on the bicycle
frame to the wheel through a slip ring arrangement.
While the display system has been described in connection with a bicycle
wheel, it will be appreciated that it can be applied to any other rotating
member for
example to an automobile wheel (or hub caps therefor) or a funfair wheel.
The bicycle may include an electric speedometer (not shown) which derives
its input ie the pulse repetition rate of the reed relay switch from the
controller.
The controller 16 can be in two parts, a first part fixed to the spoke and a
second part which can be plugged into the first part and which contains the
power
supply (the batteries) and the memory. The plug-in part can be removed for
security
purposes and/or to reprogram the memory. The controller 16 calculates the
speed and
position of the wheel 4 based on the output of the position sensor 14, and
calculates
when to flush each LED in array 10.
Instead of the trigger being provided by a reed relay, it can be provided by
an
accelerometer (not shown) mounted on the wheel at a point radially distant
from the
axis of the wheel. As the wheel rotates, the accelerometer will have a
component of
motion in the direction of the gravitational field and this will cause the
accelerometer
to generate a sinusoidal electrical output as the wheel rotates. This output
can then be
used by the controller to illuminate the LEDs at any desired attitude as the
wheel
rotates.
Of course, while only one elongate array of LEDs is disclosed, any number
* trade-mark

CA 02295768 1999-12-21
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of arrays can be mounted on the wheel in different attitudes and shapes to
form a complex
display pattern as required.
Other possible triggering devices that can replace the magnetic reed switch
arrangement include an optical or electromagnetic wave system or a Doppler
effect sound
transmitter/receiver for sensing eg a reflector on a stationary part of the
bicycle frame to
provide either a sinusoidal output synchronised with the rotation of the wheel
or a simple
impulse each time the wheel has completed one revolution.

Representative Drawing