WO2009144629A1

WO2009144629A1 - Lighting assembly

Info

Publication number: WO2009144629A1
Application number: PCT/IB2009/052101
Authority: WO
Inventors: Maarten M. J. W. Van Herpen; Oscar H. Willemsen
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2008-05-30
Filing date: 2009-05-20
Publication date: 2009-12-03
Also published as: TW201006717A

Abstract

A lighting assembly for a vehicle having a frame and at least one wheel attached to said Frame. The assembly comprises a reflective section located on said at least one wheel and comprises a reflective material. Further the assembly comprises a photo- luminescent section located on said wheel and comprises a photo-luminescent material. Further a light source for directing light to the at least one photo-luminescent section is provided. The photo-luminescent material is, at least partly, provided on an outer surface of the at least one reflective section, and/or is, at least partly, mixed with the reflective material of the at least one reflective section.

Description

Lighting assembly

FIELD OF THE INVENTION

The present invention relates to a lighting assembly for a vehicle. More in particular the present invention relates to a human powered vehicle such as a bike that is provided with a lighting assembly that can provide enhanced visibility of the vehicle at night. The invention further relates to a manufacturing method for a tire.

BACKGROUND OF THE INVENTION

Human powered vehicles, such as bicycles, scooters and wheelchairs, are generally comprised of a frame for supporting wheels and a rider, and are generally powered by movements of the rider's arms or legs. As a result of being human powered, such vehicles cannot match the nighttime visibility of motor vehicles having powerfully lit safety lighting structures such as high intensity head lamps and taillights. Instead, the prior art has generally limited safety lighting structures for human powered vehicles to minimal area reflectors and low wattage flashlight type head lamps. Due to the small amount of reflective area at various approach angles, coupled with low light intensity lamps, the known lighting structures offer only a modicum of visibility in situations in which their luminosity is overwhelmed by high intensity motor vehicle head lamps.

Furthermore, the known reflectors are only operative when an external light source, such as the lights of another vehicle, illuminates them. Hence, a biker for example at night suffers from reduced visibility when not being illuminated.

Hence, a need exists for lighting assemblies, in particular for human powered vehicles, that are highly visible and offer a large safety factor in situations of darkness both with and without the availability of external illumination.

US 7,001,051 B2 discloses a safety lighting assembly for a vehicle having a frame and at least one wheel attached to said frame, comprising at least one reflective section located on said at least one wheel and comprising a reflective material, at least one photo- luminescent section located on said wheel and comprising a photo-luminescent material, and a light source for directing light to the at least one photo-luminescent section. More in particular, US 7,001, 051 B2 discloses that the lighting assembly comprises sections formed of photo-luminescent and reflective materials. The photo-luminescent sections are placed on the sides of a human powered vehicle's wheels. A light source is mounted on the frame of the vehicle to direct light against the photo-luminescent sections as the wheels rotate. Light shining on the photo-luminescent sections causes the photo-luminescent material making up the sections to glow for a short period of time.

US 7,001,051 B2 further teaches that the reflective sections can be provided on the photo-luminescent sections, for example in the form of reflective stickers or that the photo- luminescent sections adjoin the reflective sections to form concentric circles on the vehicles tires. In the first case the light source directs light both to the photo- luminescent and reflective section(s). Although the lighting assembly of US 7,001,051 B2 provides a solution for the above-mentioned problem of visibility in the occasion that no external illumination is available, the inventors realized that the solution proposed by US 7,001,051 B2 can be improved. The solution proposed by US 7,001,051 teaches that part of the photo-luminescent layer has to be covered by the reflective material. This means that not all light directed at the wheel can reach the photo-luminescent layer and consequently that less light will be produced by that layer. In particular the inventors have realized that the photo-luminescent properties of the lighting assembly can be improved by utilizing, at least part of, the light from the light source that impedes on the reflective section(s) and is reflected therefrom to excite the photo-luminescent material.

SUMMARY OF THE INVENTION

In order to achieve this, the invention proposes in a first aspect thereof a lighting assembly for a vehicle having a frame and at least one wheel attachable to said frame, comprising a reflective section located on said at least one wheel and comprising a reflective material, and a light source for directing light to said reflective section, wherein the the assembly further comprises photo- luminescent material that is, at least partly, provided on an outer surface of said reflective section, and/or is, at least partly, mixed with the reflective material of the at least one reflective section.

By providing the photo-luminescent material on an outer surface of the reflective section, and/or, at least partly, mix the photo-luminescent material with the reflective material, light from the light source that is directed to the photo-luminescent material will also reach the reflective material. This occurs either because some of the light from the light source passes through the photo-luminescent material to reach the underlying reflective material, or because the photo-luminescent material and the reflective material are mixed to form a single layer of reflective-luminescent material and at least some of the reflected light will excite the photo-luminescent material. Hence, more light is utilized and consequently an improved photo-luminescent effect will be achieved. This is particularly important for human powered vehicles, because power usage is limited on these vehicles and consequently only relatively low-power light sources can be used.

In an advantageous embodiment of the invention the at least one wheel comprises a tire that has side faces and the photo-luminescent material and the reflective section are provided on at least one of said side faces of said tire. This ensures that the vehicle the wheel is part of is well visible from its side.

In a further advantageous embodiment of the invention the photo-luminescent material is distributed in a patterned manner. This will further enhance visibility of the vehicle that is provided with the lighting assembly. In a further advantageous embodiment of the invention the photo-luminescent material is a phosphorescent material chosen from a group comprising zinc sulphide and strontium aluminate. Phosphorescent materials have proven to be very effective at re-emitting light for prolonged periods of time.

In a further advantageous embodiment of the invention the lighting assembly comprises a control system for controlling the light source in a predetermined manner, more in particular the control system comprises a trigger device associated with said at least one wheel for generating a trigger signal for the control system and allows the control system to determine a position of said at least one wheel on the basis of the trigger signal. In this manner the on/off control of the light source can be synchronized with the rotation of the wheel and makes it possible to synchronise the emission of light with the presence of photo- luminescent material to be illuminated by the light source. This makes it for example possible to produce patterns, or in case the photo-luminescent is provided in patterns itself, to only illuminate those parts of the wheel that carry a photo-luminescent section and save energy. In a further advantageous embodiment of the invention the light source is a Light Emitting Diode (LED), in particular a LED that is arranged to emit light in the

Ultraviolet (UV) spectrum. An UV LED emits light that is not visible to the human eye and puts more emphasis on the luminescent effect. Furthermore, an UV LED has proven to be very efficient in the excitation of phosphorescent materials. A bonus effect of not being visible to the human eye is that the UV light cannot distract other traffic, in contrast to a LED that emits visible light that could distract for example car drivers.

In a further advantageous embodiment of the invention, the LED is provided with focussing means, such as a lens. This allows better focussing of the beam of light from the LED on the photo-luminescent layer and further ensures optimized utilisation of the emitted light. In a second aspect of the invention a human powered vehicle is provided having a frame and at least one wheel attached to said frame, comprising a lighting assembly according to the invention. More in particular, the human powered vehicle is a bicycle having at least one wheel that is provided with spokes, the spokes being provided with a coating of photo-luminescent material and/or being provided with means attachable thereto, said means comprising a coating of photo-luminescent material.

In a third aspect of the invention a wheel is provided comprising a tire having side faces, the wheel being particularly suited for a human powered vehicle such as a bicycle, said side faces having a reflective section comprising a reflective material, wherein photo- luminescent material is, at least partly, provided on an outer surface of the reflective section, and/or is, at least partly, mixed with the reflective material of the reflective section. In particular when the photo-luminescent material and reflective material are mixed, the resulting mixture can be easily applied to the wheel, strongly reducing manufacturing cost. In case the photo-luminescent material is provided on the reflective section, an existing wheel having a reflective section can be easily upgraded.

In a further aspect of the invention a method of manufacturing a tire is provided, comprising providing a tire having side faces, applying a reflective and/or retro- reflective material to at least part of a side face of said tire to form a reflective section on said tire, andapplying a photo-luminescent material on at least part of said reflective section to form a photo-luminescent section. Alternatively, such a method comprises providing a tire having side faces, providing a mixture of a reflective and/or retro -reflective material with a photo-luminescent material, and applying the mixture of said materials to at least part of a side face of said tire. Such materials may be provided in a base material that can be applied to the tire.

BRIEF DESCRIPTION OF THE DRAWING

These and other aspects, characteristics and advantages of the present invention will be explained in more detail by the following description with reference to the accompanying drawing, in which identical reference numerals denote identical components, and in which:

Figure 1 shows a vehicle or bicycle provided with a lighting assembly according to the invention. DETAILED DESCRIPTION

The lighting assembly according to the invention is particularly suitable to be used in combination with human powered vehicles such as bicycles, wheelchairs etc. etc. In the following description of the invention with reference to the drawing, the invention will be described when used on a bicycle. It is noted however that this is in no manner intended to limit the scope of the invention, but is used as an example only of one of the possible applications of the invention.

Figure 1 shows a human powered vehicle in particular a bicycle generally denoted with reference numeral 1. The bicycle 1 comprises a frame 2 that supports the usual components of the bicycle 1, such as a saddle, gears, brakes etcetera. The bicycle 1 further comprises a front wheel 3 and rear wheel 4, which are attached to the frame 2. The front wheel 3 is attached to the frame 2 by means of a front fork 10. The rear wheel 4 is attached to the frame 2 by means of a rear fork 11. The functioning of the bicycle 1 is know per se from the prior art and is not further explained hereinafter. The wheels 3, 4 of the bicycle 1 are provided with tires 5, 6 respectively which have side walls as is known per se from the prior art, and of which only the side walls on one side of the tires 5, 6 are visible in Figure 1. Further, the wheels 3, 4 comprise a number of spokes 7. On the side walls of the tires 5, 6 a generally circular layer 8 is provided (dashed line). The layer 8 is located on at least the side faces of the tires 5, 6 and has both (retro- )reflective and photo-luminescent properties, i.e. the layer 8 comprises at least a reflective section and a photo-luminescent section. The reflective section comprises reflective material such as metallic particles or glass beads which are dispersed in a paint. Preferably glass beads are used, because of their retro -reflective properties. The photo-luminescent section preferably comprises a phosphorescent material such as zinc sulphide or strontium aluminate. It is noted that although reflective and photo-luminescent sections are defined, these may not have to be separately identifiable sections having only such properties. The term section is mainly used to identify parts of the wheel that have predominantly reflective and/or a photo- luminescent properties. Further, such sections may even be mixed so as to have both properties as will be discussed below. In the example shown in Figure 1, the reflective-luminescent layer 8, more in particular the reflective-phosphorescent layer 8, is formed by a mixture of, for example, a reflective paint containing the aforementioned glass beads and/or metallic particles and a binder material containing zinc sulphide or strontium aluminate which particles have phosphorescent properties. The reflective- luminescent layer 8 is shown to be a continuous circular layer that is provided around the circumference of the wheels 3, 4. However, it is also possible to distribute the reflective-luminescent layer 8 in a patterned manner around said circumference. An additional advantage of a continuous circular layer is that application thereof can be done using a standard manufacturing process, which does not need to be altered, except that the paint should now contain both (retro -)reflective and luminescent particles.

The layer 8 is part of a lighting assembly which further comprises a light source, in the example of Figure 1, two light sources 20 and 21. The first light source 20 is attached to the front fork 10, the second light source 21 is attached to the rear fork 11. In Figure 1 the first light source 20, as an example, is integrated in the front fork 10 of the bicycle 1 as is schematically shown by the dashed lines. The second light source 21 is shown as a component that can be attached to the frame 2 separately. Both light sources 20, 21 are designed to direct artificial light to the layer 8 and can thus illuminate at least the photo - luminescent part setting it aglow when the associated light source is activated. Hence, a location close to the layer 8 is preferred. The light sources 20, 21 preferably comprise a Light Emitting Diode (LED) that emits blue light or UV light, the latter not being visible to the human eye, but is known to be very suitable for activating the phosphorescent material. However, any other suitable light source for producing artificial light is also possible. The light sources 20, 21 may each be provided with their own source of electrical power such as a battery, but they may also be powered by an alternator which may be mechanically coupled to the gear of the bicycle, or by solar cells which produce electrical power during daytime which can be stored for later use during night time.

When the light source 20, 21 is activated and directs (a bundle of) light to the reflective-luminescent layer 8, part of that light will be reflected by the reflective particles in said layer 8 and part of that light will set the photo-luminescent, in particular the phosphorescent material, aglow. Because the photo-luminescent material and the (retro-) reflective material are mixed to form a single layer of reflective-luminescent material at least some of the reflected light will reach the photo-luminescent material. Hence, also part of the reflected light is utilized to set the photo-luminescent material aglow and an greater photo- luminescent effect will be achieved.

Alternatively, the photo-luminescent section or material may also be provided on an outer surface of the reflective section or reflective material, i.e. the reflective material acts as a base layer for the photo-luminescent material. In this embodiment the photo- luminescent material (partly) covers the (retro -)reflective material. With this embodiment part of the light reflected by the reflective material will also reach the photo-luminescent material. Hence, also in the embodiment wherein the photo-luminescent material is provided on an outer surface of the reflective section, part of the reflected light is utilized to set the photo-luminescent material aglow and an greater photo-luminescent effect will be achieved. The photo-luminescent material can be provided on the reflective section in a patterned manner, but it is also conceivable that the photo-luminescent section is continuous but has smaller cross-sectional dimensions than the reflective section leaving part thereof uncovered. Further, it is also possible to use a combination of both embodiments, wherein part of the photo-luminescent material is provided on the reflective material and part is mixed therewith. This allows more complex patterns to be provided. Further it is possible to use pigments in either the reflective or photo-luminescent material, or phosphors that emit light in different wavelength ranges (for example blue, green, or red) so that coloured light is visible coming from the wheels.

Another way of making patterns in the light emitted by the photo-luminescent section is to provide the lighting assembly with a control system. Such a control system controls the activation of the light sources and can thus control when and for how long the photo-luminescent section is illuminated. Such a control system can be integrated in the bicycle 1 , but can also be mounted thereon, for example on the handle bars, in case the lighting assembly is mounted as an accessory later on. This is indicated in Figure 1 with reference numeral 30 which in the example of Figure 1 will for example be connected to light source 21.

With such a control system 30 it is also possible to produce patterns. In such a situation the control system 30 controls the light sources to only illuminate particular parts of the photo-luminescent material. In such a case however, the control system 30 must know the position of the wheel(s) and is for that reason provided with a trigger device associated with said at least one wheel for generating a trigger signal for the control system. Such a trigger device is for example a small magnet 31 located in the wheels 3, 4 or attached to the spokes 7 thereof, whereby in the latter case the control system 30 comprises a sensor 32 which registers when the magnet 31 passes its position. In case of a lighting system that is integrated in the bicycle 1, the magnet and sensor may be mounted in the frame 2. Another possibility is to associate the trigger system with the pedals or gears of the bicycle, but than information about the selected gear in case of a bicycle having more than one gear position needs to be supplied to the control system. In combination with a plurality of phosphors with different luminescent colors, the control system can also be used to control the colour of the luminescence, for example red emission may be produced by triggering the UV LED only when a red phosphor is below the LED, and not when a yellow or blue phosphor is below the LED. Further, the control system may comprise a manual switch to turn the light sources on or off, or to activate the control system. The control system may also be provided with a daylight sensor which activates the control system automatically in case of darkness.

In an alternative embodiment of the invention the spokes 7 of the bicycle 1 may be coated with a photo-luminescent material or so-called add-ons provided with a layer of photo-luminescent material may be attached to the spokes 7 of the bicycle. It shall be understood that the position of the light sources 20, 21 in such a case need to correspond with the position of the add-ons. In case of coated spokes, the light sources preferably comprise an array of individual light sources, such as an array of LED' s. This is not shown in the Figure. In order to further improve the working of the light assembly according to the invention, the light sources 20, 21, in particular the LED's, are provided with a focussing means such as an optical lens. This provides a more focussed beam of light.

The present invention has the advantage that very easily a wheel, and in particular a tire can be provided that has both (retro -)reflective and photo-luminescent properties. In fact, within the scope of the invention also a method of manufacturing a tire having such properties is comprised, wherein such a method comprises providing a tire having side faces, applying a reflective and/or retro -reflective material to at least part of a side face of said tire to form a reflective section on said tire, and applying a photo- luminescent material on at least part of said reflective section to form a photo-luminescent section. With this method for example a standard bicycle tire can be easily upgraded with a photo-luminescent section, or when manufacturing the tire, a (retro -)reflective section and a photo-luminescent section can be provided using standard manufacturing equipment. The latter advantage in particular applies when the method comprises providing a tire having side faces, providing a mixture of a reflective and/or retro-reflective material with a photo- luminescent material, and applying the mixture of said materials to at least part of a side face of said tire. In this case the tire can be provided with a layer of material having both (retro- deflective and photo-luminescent properties in a single manufacturing step.

As an example, the reflective and/or retro -reflective material and the photo- luminescent material are provided in a base material that can be applied to the tire. Such a base material is for example a paint.

Claims

CLAIMS:

1. A lighting assembly for a vehicle having a frame and at least one wheel attachable to said frame, the assembly comprising

- a reflective section located on said at least one wheel and comprising a reflective material;

- a light source for directing light to said reflective section, characterized in that the assembly further comprises a photo-luminescent material that is, at least partly, provided on an outer surface of said reflective section, and/or is, at least partly, mixed with the reflective material of said reflective section.

2. The lighting assembly according to claim 1, wherein the at least one wheel comprises a tire having side faces and wherein the photo-luminescent material and the reflective section are provided on at least one of said side faces of said tire.

3. The lighting assembly according to claim 2, wherein the reflective section and/or the photo-luminescent material is continuously distributed over said at least one face.

4. The lighting assembly according to any of the claims 1 to 3, wherein the photo-luminescent material is a phosphorescent material chosen from a group comprising zinc sulphide and strontium aluminate.

5. The lighting assembly according to claim 4, wherein the phosphorescent material is provided with a pigment material.

6. The lighting assembly according to any of the previous claims, comprising a control system for controlling the light source.

7. The lighting assembly of claim 6, wherein the control system comprises a trigger device associated with said at least one wheel for generating a trigger signal for the control system.

8. The lighting assembly of claim 7, wherein the control system is arranged to determine a position of said at least one wheel on the basis of said trigger signal.

9. The lighting assembly of any of the claims 6 to 8, wherein the control system comprises a daylight sensor.

10. The lighting assembly according to any of the previous claims, wherein the light source is a Light Emitting Diode (LED), in particular a LED that is arranged to emit light in the Ultraviolet (UV) spectrum.

11. Human powered vehicle having a frame and at least one wheel attached to said frame, comprising a lighting assembly according to any of the claims 1 to 10.

12. Vehicle according to claim 11, wherein the light source is attached to the frame and is directed to the at least one wheel.

13. Vehicle according to claim 11 or 12, wherein the vehicle is a bicycle having at least one wheel having spokes, the spokes being provided with a coating of photo- luminescent material and/or being provided with means attachable thereto, said means comprising a coating of photo-luminescent material.

14. A wheel comprising a tire having side faces, in particular for a human powered vehicle such as a bicycle, said side faces having a reflective section comprising a reflective material, wherein photo-luminescent material is, at least partly, provided on an outer surface of the reflective section, and/or is, at least partly, mixed with the reflective material of the at least one reflective section.

15. Method of manufacturing a tire, comprising

- providing a tire having side faces, - applying a reflective and/or retro -reflective material to at least part of a side face of said tire to form a reflective section on said tire, and

- applying a photo-luminescent material on at least part of said reflective section to form a photo-luminescent section.

16. Method of manufacturing a tire, comprising

- providing a tire having side faces,

- providing a mixture of a reflective and/or retro -reflective material with a photo-luminescent material, and - applying the mixture of said materials to at least part of a side face of said tire.