GB2607868A

GB2607868A - A safety device for cyclists

Info

Publication number: GB2607868A
Application number: GB2108084.1A
Authority: GB
Inventors: Pieters Max; Powell Guy
Original assignee: P&p Innovation Ltd
Current assignee: P&p Innovation Ltd
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2022-12-21
Also published as: GB202108084D0; WO2022258955A1; GB202208328D0

Abstract

A bicycle light 1 is removably attached to a bicycle, and comprises a projection portion (4, figure 1) adapted to emit light to project an image 26 onto a road surface. The image 26 is projected onto the ground on only one side of the bicycle and into a region between the forwardmost and rearmost extremities of the bicycle and no more than three metres to the side on level ground. The image 26 may be static or animated, and the light 1 may further comprise a rearward projecting light source (7, figure 1). The light may also detect a speed of travel and alter the projected image depending thereon.

Description

Title: A safety device for cyclists

Description of Invention

This invention relates to a safety device for cyclists, and in particular concerns a bicycle light for increasing the safety of cyclists, especially in darkness or other conditions of low visibility.

Cycling, including e-biking, continues to become increasingly popular as a means of transport and leisure in the UK and beyond. The UK is in the course of transitioning to a low carbon economy and aims to reach net zero emissions by 2050. The UK government has also enshrined in law a target to cut emissions by 78% by 2035, The widespread use of cycling is seen as a key part of this Process.

Cycling provides many benefits, not only with regard to the health and wellbeing of people who engage in cycling rather than other form of commuting/travel, but also relating to road congestion and air quality, particularly in major cities.

However, safety is a concern for cyclists, particularly where cyclists come into close proximity to cars and other motor vehicles. From a Mintel research report (Cycling UK March 2019, called "Barriers to Cycling") among those who either do not cycle at all or cycle less than weekly, the main deterrent was concern about safety on the roads, selected by 45% of respondents. The research also indicated that, while it is the leading concern of both sexes, it is particularly a barrier to greater female take-up of cycling (this option was selected by 4896 of female respondents, and 40% of male respondents).

If the visibility of a cyclist can be increased, then the chances of an accident involving the cyclist and a motor vehicle will be reduced.

In recent years, the "Blaze" cycle light has become popular. The Blaze product includes a laser projector which is mounted on or around the handle bars of a bicycle, and which projects an image of bicycle onto the road surface around 2m immediately ahead of the bicycle. This allows people ahead of the bicycle to see clearly and immediately that a cyclist is approaching, and for instance will significantly reduce the chance of a pedestrian stepping into a road or cycle path as the cyclist approaches.

It is an object of the invention to provide an illumination device for a bicycle that improves the safety of a person riding the bicycle.

Accordingly, one aspect of the present invention provides a bicycle light comprising: an attachment portion adapted to be removably attached to a part of a bicycle; and a projection portion adapted to emit light to project an image onto a surface, wherein: the attachment portion and the projection portion are connected to one another such that, when the attachment portion is attached to the part of the bicycle, the image is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length; and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.

Advantageously, the attachment portion is adapted to be removably attached to a substantially tubular member.

Preferably the bicycle light includes a light source.

Conveniently, the bicycle light further comprises an image formation arrangement, to cause the light produced by the light source to be emitted such that it forms an image having a predetermined form on a surface.

Advantageously, the image formation arrangement comprises a diffractive optical element, an image slide, or an electro-optical light modifier.

Preferably, the bicycle light further comprises a focusing arrangement to focus light emitted by the light source.

Conveniently, the image comprises an image of a bicycle and/or a cyclist.

Advantageously, the image that is projected by the projection portion is programmable.

Preferably, the image that is projected by the projection portion is static or substantially static.

Alternatively, the image that is projected by the projection portion is moving and/or animated.

Conveniently, the light has a sensor to detect the speed of the bicycle, or is configured to receive an input from an external sensor which detects the speed of the bicycle, and wherein the image that is projected by the projection portion depends at least partly upon the speed of the bicycle.

Advantageously, one or more speed thresholds are defined, and wherein the image that is projected by the projection portion changes automatically depending on whether the speed of the bicycle is above or below each of the thresholds.

Preferably, the bicycle light further comprises a second, independent light source.

Conveniently, the second light source is arranged such that, when the attachment portion is attached to the part of the bicycle, light from the second light source is emitted in a direction which is generally rearwardly of the bicycle.

Advantageously, when the attachment portion is attached to a part of the bicycle having a height between around 45cm and 135cm above the region of ground, the image formed on the region of ground has a length, in the direction parallel with the axis of travel, of at least 0.6 metres, preferably at least 1.5 metres, and more preferably at least 2 metres, and yet more preferably at least 3 metres.

Preferably, when the attachment portion is attached to a part of the bicycle having a height between around 45cm and 135cm above the region of ground, the image formed on the region of ground has a width, in the direction perpendicular to the axis of travel, of at least 0.5 metres, preferably at least 1 metre, and more preferably at least 1.5 metres.

Another aspect of the present invention provides a combination of a bicycle, and a bicycle light according to any preceding claim, wherein the bicycle light is attached to a part of the bicycle such that the image is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length, and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.

Conveniently, the part of the bicycle comprises a seat post of the bicycle.

A further aspect of the present invention provides a method of projecting an image from a bicycle, comprising the steps of: providing a bicycle light according to any one of the above; and attaching the bicycle light to a part of the bicycle, so that the image projected by the bicycle light is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length, and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.

In order that the invention may be more readily understood, embodiments therefore will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a projector in accordance with the present invention; Figures 2 and 3 show the projector of figure 1 attached to a bicycle; Figures 4a and 4b show a bicycle travelling on a road, respectively without and with the projector of figure 1; and Figure 5 shows the projector of figure 1 attached to a bicycle, projecting an alternative image.

Referring firstly to figure 1, a projector 1 embodying the present invention is shown attached to a seat post 2 of a bicycle. The projector 1 is, in the example shown, attached at a top region of the seat post 2, just below the saddle 3 of the bicycle. However, it should be understood that the invention is not limited to this, and the projector 1 may be attached to any other suitable pail of a bicycle, including but not limited to the handlebars, head tube, top tube, down tube, seat stay, chain stay, seat tube or saddle.

The projector 1 may be attached to the seat post 2 in any suitable manner, for instance by way of a pair of resilient, arcuate arms (not shown) which fit closely around the seat post 2, and which are joined at their free ends by a bolt which is tightened to draw the arms towards one another.

The invention is not limited to this, and any attachment method may be used, which allows the projector 1 to be removably attached to the seat post 2 such that its height on the seat post 2, and its orientation with respect to the seat post 2, are firmly maintained and the projector 1 will not be dislodged or deflected if the bicycle is ridden over uneven ground.

In preferred embodiments, the projector 1 may be attached to, and removed from, the seat post 2 without the use of any specialised tools. It is preferred that the projector 1 can be attached to, and removed from, the seat post 2 using only the user's hands, and a skilled reader will readily appreciate how this may be achieved.

The projector 1 includes a light source, to generate visible light. In preferred embodiments of the invention, the light source includes a laser, but this is not essential and any suitable light source, such as one or more LEDs, may also be used.

The projector 1 may also include an optical arrangement, for instance to reflect and/or focus the light emitted by the light source. Any suitable optical arrangement may be used, and the skilled reader will be well aware of the various optical arrangements that are available.

The projector 1 also includes an arrangement for modifying, directing and/or selectively blocking the light emitted from the light source, so that the light emitted by the projector 1 forms an image having a predetermined shape and/or form when it impinges upon a surface. As examples of this, light emitted by the light source may shine through a diffractive optical element, or through a static imaging element such as an image slide (which may comprise an element having one or more apertures formed therethrough which correspond to the shape of the desired image), or be reflected from a dynamic source such as a DLP (digital light processing) element or other electro-optical light modifier. The invention is not limited to these examples, and any other suitable arrangement may equally be used.

Returning to figure 1, the projector 1 includes an aperture 4 through which light is emitted by the projector 1, as discussed above. In practical embodiments the aperture 4 is likely to have a lens, window or other transparent or translucent covering.

In preferred embodiments of the invention, the direction in which the aperture 4 points with respect to a main body 5 of the projector 1 may be adjusted. For instance, the aperture 4 may be formed on a projection arm 6 which is movable with respect to the main body 5. The connections which allow the projector 1 to be attached to the seat post 2 may be formed on the main body 5, and once the main body 5 is fixed in place with respect to the seat post 2 then the projection arm 6 may be tilted and/or pivoted into a desired orientation with respect to the main body 5.

Once again, the projection arm 6 may be fixed robustly in place in the desired orientation, so that the angle in which it points with respect to the main body 5 will not be altered if the bicycle is ridden over uneven ground.

In the embodiment shown in figure 1, the projector 1 also includes a rear light 7. The rear light 7 takes the form of one or more light sources which, when the projector 1 is attached to a seat post 2, will shine generally in the direction which is rearward of the bicycle.

Preferably, the light source(s) which constitute the rear light 7 are separate from the light source(s) which emit an image, as discussed above. In accordance with convention the rear light 7 may be orange or red in colour, or both. For instance, a rear-facing portion may be red, and side-facing portions may be orange, similar to the colours of some rear car lights. This effect could be achieved with separate light elements, or with one continuous LED display.

In the embodiments shown the rear light 7 is provided as part of the projector 1 for convenience, to avoid the need to attach two independent light sources to the seat post 2 of the bicycle. However, this is optional and in other embodiments the projector 1 does not include a rear light.

The projector 1 preferably includes a power source, such as one or more batteries. Any suitable means of powering the projector 1 may be used, for instance a connection to a dynamo (which may be powered by rotation of one of the bicycle wheels) and/or solar cells which are conveniently positioned, for instance being attached to an upper-facing region of the bicycle.

Turning to figure 2, a bicycle 8 is shown, with the projector 1 attached to the seat post 2 thereof. In the arrangement shown in figure 2, the bicycle 8 is travelling in a substantially straight line along an axis of travel 9.

The projector 1 projects an image 10 into a projection region 11.

In preferred embodiments of the invention, the projection region 11 lies only, or substantially only, on one side of the axis of travel 9. In the example shown in figure 2, the projection region 11 lies solely on the right-hand side of the axis of travel 9 (viewed in the direction in which the bicycle 8 is travelling), and does not extend to any region on the left-hand side of the axis of travel 9.

In the example shown in figure 2, the image 10 comprises a schematic representation of a cyclist, involving two wheels 12 and a figure 13, positioned so as to be riding a bicycle which includes the wheels 12. In the example shown, the image 10 is formed so that, looking directly down onto the bicycle 8, the bottom edge 25 of the image 10 lies closest to the axis of travel 9, and the top edge 26 of the image (including the head 14 of the figure 13) lies furthest from the axis of travel 9.

The image 10 is preferably of a size which is comparable to the size of the bicycle 8. In the example shown the wheels 12 of the image 10 lie approximately adjacent the wheels 27 of the bicycle 8.

In preferred embodiments the length of the image 10 (measured in the direction parallel with the axis of travel 9) is at least 1.5m, and is preferably at least 2m. In some embodiments the image 10 may have a length of at least 3m.

The size of the image will depend, in part, on the size of the bicycle to which the projector 1 is to be attached. It is envisaged that embodiments of the invention may be used with all kinds of bicycles, including "first bikes" (which may be of a balance bike construction, i.e. without pedals and where the rider propels him/herself by pushing directly against the ground) up to full-sized adult bicycles. In preferred embodiments of the invention for use with an adult bicycle, the width of the image 10, measured in a direction perpendicular to the axis of travel 9, is at least 1m, and may be at least 1.5m. In some embodiments the width of the image 10 may be 2m, 2.5m, 3m or more. For a children's bicycle, the width of the image 10, measured in a direction perpendicular to the axis of travel 9, may be at least 0.5m.

In figure 2 a mid-point line 15 is shown. The mid-point line 15 lies approximately half way between the rear tip of the rear wheel and the front tip of the front wheel, and is shown extending vertically upwardly from the axis of travel 9, and also laterally at ground level, perpendicular to the axis of travel 9, through the projection region 11.

In preferred embodiments of the invention, the image 10 lies both forwardly and rearwardly of the mid-point line 15.

In more preferred embodiments, for an adult bicycle, the image 10 projects at least 0.5m, and more preferably at least 0.75m, more preferably at least 1m, and yet more preferably at least 1.5m, both forwardly and rearwardly from the mid-point line 15. It is also envisaged that, for a child's bicycle, the image may be smaller than this, and may for instance extend by 0.4m forwardly and rearwardly from the mid-point line 15.

As the skilled reader will understand, these dimensions are expressed in terms of the size of the image 10 which is produced when the projector 1 is attached to a bicycle, and correctly oriented so that light emitted by the projector 1 impinges on a horizontal and planar surface on which the bicycle is travelling. The skilled reader will readily be able to calculate the properties of a projector 1 that will give rise to such an image. For example, with reference to figure 3, the bicycle 8 is shown from a rear view, with an image 10 being projected onto a road surface on which the bicycle 8 is travelling. The image 10 has a bottom edge 25, which lies closest to the axis of travel 9, and a top edge 26 which lies furthest from the axis of travel 9. Merely as examples, the projector 1 is fixed at a height of 75cm above the road surface 28, the bottom edge 25 lies at 20cm from the axis of travel 9, and the top edge 26 lies at 150cm from the axis of travel 9. The projector 1 emits a beam 29 having an inner edge 30, which corresponds to the bottom edge 25 of the image 10, and an outer edge 31, which corresponds to the top edge 26 of the image 10.

By using standard geometry, it can be determined that the inner edge 30 of the beam 29 lies at an angle 32 of approximately 15° to vertical, and the outer edge 31 of the beam 29 lies at an angle 33 of approximately 63°.

The angles required for the length of the image can be calculated in a similar manner (by considering the "pan" as well as "tilt" direction). The skilled person will therefore be able to calculate the angle of orientation, and width of beam, that is required for a projector to be able to form an image of the required size.

When the projector 1 is activated and the image 10 is projected onto a road or other surface beside the bicycle 8, the safely of the cyclist will be significantly improved.

In embodiments of the invention, the projector 1 has an attachment portion, which defines an attachment axis. The attachment portion may be configured to be removably attached to a tubular or substantially tubular member having a longitudinal axis, and this longitudinal axis (when the attachment portion sis attached to the tubular member) defines the attachment axis of the attachment portion. For instance, the attachment portion may comprise two halves of a sleeve, which when fitted together define a complete or substantially complete tube having a main longitudinal axis. These two halves may be configured to be fitted around a tubular member (such as a seat post or part of a frame of a bicycle), which has a longitudinal axis. When the attachment portion is attached to the tubular member, the axis of the tube formed by the two halves of the sleeve is parallel or substantially parallel with the axis of the tubular member.

In such embodiments, the projector 1 also has a projection direction, which is the direction in which light is emitted from the aperture 4 of the projector 1 to form the image 10.

The projector 1 may be configured such that the attachment portion can be fixed with respect to the aperture 4, such that when the attachment portion is attached to a part of a bicycle, the aperture 4 is oriented such that it will project an image in the desired direction.

For instance, the projector 1 may be adapted to be attached to a seat post of a bicycle. A seat post will generally be tubular, and in use will be oriented vertically or substantially vertically. The projector may be configured such that the aperture may be fixed in place with respect to the attachment portion, so that when the attachment portion is attached to a vertical tubular member, the aperture points in the correct direction to project the desired image.

Figure 4A shows an aerial view of a road 16, including a lane 17 having an inner edge 18 (which may for instance be adjacent a pavement 19), and an outer edge 20, which in this instance is coincident with a centre-line of the road 16.

The lane 17 is shared between cars and cyclists. In this example, traffic is travelling on the left-hand side of the road, for instance as in the UK, Ireland and Japan, although the skilled reader will readily understand how the situation will appear in countries where traffic is on the right-hand side of the road.

In figure 4A, a cyclist 21 is travelling along the lane 17, near the inner edge 18 thereof. Three cars 22a, 22b, 22c are also travelling along the lane 17. A middle one of these cars 22b is passing the cyclist 21, and in order to accommodate the cyclist 21 has moved further towards the outer edge 20 of the lane 17, but only by a small distance so that a relatively small clearance 23 is present between the cyclist 21 and the car 22b (measured in the direction which is perpendicular with the direction of the lane 17).

In figure 4A, the cyclist is not equipped with a projector as discussed above.

Figure 4B shows a similar scene, in which the cyclist 21 is riding a bicycle 8 equipped with a projector as discussed above, and an image 10 is therefore projected onto the surface of the lane 17 Not only does the image provide an immediate visual cue to the drivers of the cars 22a, 22b, 22c that the cyclist 21 is present, but the image 10 also creates a region on the surface of the road 16 which drivers of cars will seek to avoid.

In figure 4B, the car 22b which is overtaking the cyclist 21 will therefore move further towards (and onto or past) the outer edge 20 of the lane 17 by sufficient distance that the car 22b avoids the image 10. This leads to a clearance 23 between the car 22b and the cyclist 21 which is at least as great as the width of the image 10, and is significantly greater than the clearance 23 which occurs in figure 4a.

The skilled reader will therefore appreciate that the positioning of an image immediately beside a bicycle, with a length which is comparable to that of the bicycle and a width which extends to at least 1m laterally away from the axis of travel of the bicycle, creates a clearly visible and well-defined zone which drivers of cars and other motor vehicles will avoid, thus giving the cyclist significantly more space and increasing the safety of the cyclist.

This will particularly be the case in darkness or other conditions of poor visibility (such as fog).

As mentioned above, the image 10 is preferably projected on one side only of the bicycle. As can be understood with reference to figures 4a and 4b, a cyclist 21 will generally travel near the inner edge 18 of a lane 17, and will be passed by motor vehicles on the outer side (i.e. the side furthest from the inner edge 18 of the lane 17).

A projection on the inner side of the bicycle is therefore generally not needed, and projecting only on one side of the bicycle leads to a simpler design, and also saves power, by projecting only where the image is required.

As discussed above, the image shown in figure 2 is a simplified figure of a cyclist. However, any suitable image may be used. For instance, an image of a figure riding a penny farthing, or an image of a unicorn, may be used. It is also not necessary that, where a figure such as a cyclist is used, that the figure is in any particular orientation. For instance, with reference to figure 2, the representation of the cyclist could be the other way up, i.e. with the head 14 nearest to the centreline 9, or the representation of the cyclist could appear to be pointing in the opposite direction, i.e. rotated around the mid-point line 15.

Figure 5 shows another potential image, which comprises a pair of arrows 24, which point generally laterally away from the axis of travel 9 of the bicycle 8, indicating clearly to a driver of the motor vehicle 22b that the motor vehicle 22b should pull out towards the outer edge of the lane, to allow the cyclist sufficient space when passing the cyclist. Here, the direction in which the arrows 24 point indicates the direction in which the motor vehicle 22b should manoeuvre in order to pass the cyclist safely.

In embodiments of the invention, the image may comprise only one colour of light. However, in other embodiments, the image may comprise two or more different colours of light, which form part of an image. For instance, in the example of figure 5, the arrows 24 may be projected in a red colour, to be clearly visible and attention-grabbing, and the image may include a second colour (for instance yellow) forming other parts of the image around the red parts of the arrows 24.

It is also envisaged that the image projected by the projector may not be stationary, and may be a moving image With respect to the example shown in figure 2, the simplified figure of the cyclist may pedal, or wave With regard to the example shown in figure 4, the arrows may move in the direction generally laterally outwardly away from the axis of travel 9 of the bicycle 8, either in a reciprocating motion or in a continuous "flow" of arrows, which appear at or near the axis of travel 9 of the bicycle 8, and move outwardly towards the outer edge of the projection region 11 before disappearing.

The projector 1 preferably includes controls, and in its most simple form may comprise an on-off switch so that the image can be turned on or off. Other controls, for example allowing a user to vary the intensity, brightness, size (as a whole, or independently in the directions perpendicular with and parallel to the axis of travel 9), and/or focus of the image may also be provided on the projector 1. These controls may take any suitable form.

The projector 1 may also be programmable, and this may be through controls which are provided on the projector 1 itself, or through commands which are input into a separate device and then communicated to the projector, for instance through an app or other program on a mobile phone, tablet or other device, or through a desktop or laptop computer. The commands may be transferred to the projector through a wired connection, or through a wireless connection of any kind (such as a Bluetooth connection). In this way a user may be able to determine the image that is projected, for instance by choosing from a pre-set bank or gallery of images, or by inputting or uploading an image file in any suitable form. The projector 1 may also be configured to receive inputs based on gestures performed by the user. For instance, a smart watch such as an Apple watch could be linked (directly or indirectly) to the projector 1, and certain movements of the user could correspond to instructions to change the image that is projected by the projector 1, and/or change other properties of the projection, such as the size of the projection, the brightness of the projection, the speed of any animation of the projection, or whether the projection is on or off.

In some embodiments, the projector may be equipped with, or connected to, one or more sensors which allow the projector to determine whether the bicycle is moving. This may be through one or more accelerometers, a connection to a moving part of the bicycle, such as one of the wheels, or through inclusion of, or connection to, a positioning apparatus such as a GPS sensor. If it determined that the bicycle has come to a stop, or the speed is dropped below a pre-set threshold, the image may be deactivated, to save power. However, some users may not wish to make use of this facility, as (for instance) when waiting at a red traffic light the user may still wish the image to be present, to indicate to drivers around the cyclist that the area around the cyclist should be kept clear when the traffic begins to move again.

In examples of the invention, the image that is projected may depend on the speed at which the bicycle is moving. One or more thresholds may be defined, with a different image being projected depending on whether the speed of the bicycle is above the threshold. The one or more thresholds may be adjustable by the user.

For example, the system may be configured so that two thresholds are defined. A first threshold is set so that, below the first threshold, the bicycle is deemed to be travelling at low speed. The second threshold is higher than the first threshold, and between the first and second thresholds the bicycle is determined to be travelling at medium speed. Above the second threshold the bicycle is determined to be travelling at high speed.

As one example, below the first threshold, the image projected may be that of a rider on a penny farthing. Between the first and second threshold, an image of a regular cyclist (such as shown in figure 2) may be projected. Above the second threshold, the image may be one that represents or suggests high speed, such as a rocket, or an image of a cyclist in a streamlined, racing-type position. These changes would take place automatically depending on the speed of the bicycle relative to the thresholds, and would not need any further active input from the user.

As another example, the colour of the projected image may change with the speed of the bicycle. If the same thresholds are used as in the above example, below the first threshold the projected image may be blue. Between the first and second thresholds the image may be green, and above the second threshold the image may be red. As yet a further possibility, the colour may change in a continuous or substantially continuous manner depending on the speed of the bicycle.

In examples of this kind, the user may set the thresholds to be "target" speeds at which the user would like to cycle, and the user can then use the projected image as an easy visual indication of his/her speed. It is also envisaged that, as the system grows in popularity and is adopted by many users, cyclists will compete with each other to travel at sufficient speeds for the system to show a particular projected image.

A certain image may also be projected when the bicycle is at rest, or travelling below a certain threshold. For instance, this image could be a representation of a cyclist at rest, or (in the case of a moving or animated image) show the cyclist slowing down, or breathing more slowly.

The above document makes reference to the use of the projector on a bicycle. However, the invention is not limited to this, and projectors as discussed above may be used with any two-wheeled vehicle, including but not limited to e-bikes, scooters, e-scooters, mopeds and Segway (RTM) -type vehicles. The invention may also be used with one-wheeled vehicles (such as unicycles) and vehicles with three or more wheels, such as tricycles and mobility scooters.

The skilled reader will understand that the invention provides an advantageous safety device that will increase the visibility and safety of cyclists in many different circumstances.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims: A bicycle light comprising: an attachment portion adapted to be removably attached to a part of a bicycle; and a projection portion adapted to emit light to project an image onto a surface, wherein: the attachment portion and the projection portion are connected to one another such that, when the attachment portion is attached to the part of the bicycle, the image is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length; and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.
2. A bicycle light according to claim 1, wherein the attachment portion is adapted to be removably attached to a substantially tubular member.
A bicycle light according to claim 1 or 2, including a light source.
4. A bicycle light according to claim 3, further comprising an image formation arrangement, to cause the light produced by the light source to be emitted such that it forms an image having a predetermined form on a surface.
5. A bicycle light according to claim 4, wherein the image formation arrangement comprises a diffractive optical element, an image slide, or an electro-optical light modifier.
6. A bicycle light according to any one of claims 3 to 5, further comprising a focusing arrangement to focus light emitted by the light source.
7. A bicycle light according to any preceding claim, wherein the image comprises an image of a bicycle and/or a cyclist.
8. A bicycle light according to any preceding claim, wherein the image that is projected by the projection portion is programmable.
9. A bicycle light according to any preceding claim, wherein the image that is projected by the projection portion is static or substantially static.
10. A bicycle light according to any preceding claim, wherein the image that is projected by the projection portion is moving and/or animated.
11. A bicycle light according to any preceding claim, wherein the light has a sensor to detect the speed of the bicycle, or is configured to receive an input from an external sensor which detects the speed of the bicycle, and wherein the image that is projected by the projection portion depends at least partly upon the speed of the bicycle.
12. A bicycle light according to claim 11, where one or more speed thresholds are defined, and wherein the image that is projected by the projection portion changes automatically depending on whether the speed of the bicycle is above or below each of the thresholds.
13. A bicycle light according to any preceding claim, further comprising a second, independent light source.
14. A bicycle light according to claim 13, wherein the second light source is arranged such that, when the attachment portion is attached to the part of the bicycle, light from the second light source is emitted in a direction which is generally rearwardly of the bicycle.
15. A bicycle light according to any preceding claim wherein, when the attachment portion is attached to a part of the bicycle having a height between around 45cm and 135cm above the region of ground, the image formed on the region of ground has a length, in the direction parallel with the axis of travel, of at least 0.6 metres, preferably at least 1.5 metres, and more preferably at least 2 metres, and yet more preferably at least 3 metres.
16. A bicycle light according to any preceding claim wherein, when the attachment portion is attached to a part of the bicycle having a height between around 45cm and 135cm above the region of ground, the image formed on the region of ground has a width, in the direction perpendicular to the axis of travel, of at least 0.5 metres, preferably at least 1 metre, and more preferably at least 1.5 metres.
17. A combination of a bicycle, and a bicycle light according to any preceding claim, wherein the bicycle light is attached to a part of the bicycle such that the image is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length, and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.
18. A combination according to claim 17, wherein the part of the bicycle comprises a seat post of the bicycle.
19. A method of projecting an image from a bicycle, comprising the steps of: providing a bicycle light according to any one of claims 1 to 16; and attaching the bicycle light to a part of the bicycle, so that the image projected by the bicycle light is projected onto the ground on only one of the two sides of the bicycle separated by a plane bisecting the frame of the bicycle along its height and length, and if the bicycle is upright on a substantially horizontal region of ground, oriented so that the frame of the bicycle is aligned with an axis of travel which is defined at ground level, the part of the ground onto which the image is projected is at most 3 metres away from the axis of travel, and within a region defined by parallel lines which are perpendicular to the axis of travel aligned with the forwardmost and rearmost portions of the bicycle.