GB2554403B

GB2554403B - A lamp assembly for an automobile, a headlamp comprising such a lamp assembly, and an automobile comprising such a lamp assembly

Info

Publication number: GB2554403B
Application number: GB1616278.6A
Authority: GB
Inventors: Esders James
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2016-09-05
Filing date: 2016-09-26
Publication date: 2019-10-09
Anticipated expiration: 2036-09-26
Also published as: GB201615007D0; GB2554403A; GB201616278D0

Description

A LAMP ASSEMBLY FOR AN AUTOMOBILE, A HEADLAMP COMPRISING SUCH A LAMP ASSEMBLY, AND AN AUTOMOBILE COMPRISING SUCH A LAMP ASSEMBLY

FIELD OF INVENTION

The present invention relates to a lamp assembly for an automobile. The invention has been developed for use in automotive headlamp assemblies and will be described with reference to that application. It will be appreciated, however, that the invention has application in other contexts, such as in tail-light assemblies.

BACKGROUND

An automotive headlamp assembly may include one or more lamp types, such as turn indication lights (“indicators”), parking lights, fog lights and/or headlights. Increasingly, the lights for some or all of these functions are integrated into a single pre-assembled housing that can be installed during manufacture of an automobile such as a car.

Certain lights of the lamp assembly may need to meet visibility requirements when installed in a car. For example, a parking light may need to be visible not just from directly in front of the car, but also from some angle across the front of the car. This requirement may be driven by functionality and/or legal requirements. For example, it may be a legal requirement for a parking light on one side of a car to be visible from the other side of the car at some particular angle, such as 45 degrees.

As shown in Fig. 1, where the front 100 of a car 102 is relatively square in plan, a parking light 104 is easily visible to a viewer 106 located 45 degrees off to the right hand side of the car 102.

Over time, the front corners of automobiles have become increasingly raked (in plan), at least in part to reduce wind resistance and improve fuel economy. One difficulty with this increased rake is that lights in a headlamp assembly on one side of the car become decreasingly visible from the other side of the car. For example, as shown in Fig. 2 (in which reference numbers from Fig. 1 are used to indicate like features), the position of the left parking light 104 combined with the steep rake of the front 100 of the car 102 means that the left parking light 104 is obscured from the viewer 106 located 45 degrees off to the right hand side of the car 102. The actual viewing angle is considerably less than 45 degrees.

This problem can be addressed by adding an additional light source that is visible from the desired angle, such as, for example, from 45 degrees off to the opposite side of the automobile. However, this adds cost and complexity, especially where several lights within a lamp assembly may need to meet visibility requirements.

SUMMARY OF INVENTION

In accordance with a first aspect of the invention, there is provided a lamp assembly for a vehicle, the lamp assembly comprising: an at least partially transparent lens or lens cover; a first light redirector for redirecting at least some light produced by a light source, such that at least a portion of the redirected light is repeatedly reflected along at least one curved surface of the lens or lens cover; a second light redirector for redirecting at least some of the reflected light such that it exits the lens or lens cover, wherein at least some of the redirected light reflects repeatedly off an internal interface of the lens or lens cover.

The assembly may include the light source.

The first light redirector may comprise at least one reflector, diffractor, and/or refractor.

The lamp assembly may comprise a diffuser for diffusing at least some of the light such that it exits the lens adjacent the first light redirector.

The first light redirector may be disposed on, or in contact with, the lens or lens cover.

The first light redirector may be moulded, machined or formed in or with, or otherwise form an integral part of, the lens or lens cover.

The first light redirector may be arranged such that, in use, when the lens is provided on a vehicle, the first light director extends generally vertically.

The second light redirector may comprise at least one reflector, diffractor, and/or refractor.

The second light redirector may be disposed on, or in contact with, the lens or lens cover.

The second light redirector may be moulded, machined or formed in or with, or otherwise forms an integral part of, the lens or lens cover.

The light source may be for a parking light, a turn indicator, a tail light or a stop light.

The lamp assembly may be configured such that, when installed in a vehicle, the light that exits the lens or lens cover includes a component that diagonally crosses a longitudinal axis of the vehicle.

The component may cross the longitudinal axis of the vehicle at an angle of at least 45 degrees relative to the longitudinal axis.

According to a second aspect of the invention, there is provided a headlamp comprising a lamp assembly according to the first aspect of the invention.

According to a third aspect of the invention, there is provided a vehicle comprising a lamp assembly according to the first aspect of the invention.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a plan view of a car;

Fig. 2 is a plan view of a different car to that of Fig. 1, with more steeply raked front corners;

Fig. 3 is a perspective view of a light assembly according to the invention;

Fig. 4 is a schematic view of a horizontal section through the lamp assembly of Fig. 3;

Fig. 5 is a side elevation of the lamp assembly of Fig. 3 installed in an automobile in the form of a car, according to the invention;

Fig. 6 is a perspective view of an alternative light assembly according to the invention;

Fig. 7 is a horizontal section through the lamp assembly of Fig. 6; and

Fig. 8 is a detailed view of the horizontal section of Fig. 7.

All drawings are schematic and are not to scale. Some details may have been omitted or simplified to assist in understanding how an embodiment and/or the invention operates. No drawing should be interpreted as relating to a particular vehicle model or type.

DETAILED DESCRIPTION

Referring to Figs 3 to 5, a lamp assembly in the form of a headlamp assembly 200 includes a transparent lens cover 202. The lens cover 202 covers several headlamps, such as high beam headlamp 203 and low beam headlamp 205. A first lens 207 is positioned in front of the high beam headlamp 203, and a second lens 209 is positioned in front of the low beam headlamp 205, to focus and/or directionally refract light from their respective headlamps.

The lamp assembly 200 also includes a light source in the form of a light emitting diode (LED) light 204 positioned behind the lens cover 202. It will be understood that the LED light 204 may include one or more LEDs along with any reflecting and/or refracting features needed to focus, collimate or defocus the light from the LED(s) so that it moves in the desired direction with the desired dispersion characteristics. In this embodiment, the LED light 204 is for a parking light, but in other embodiments may be for an indicator, fog light, or other light of the type used in headlamp assemblies. A first light redirector in the form of a first refractor 206 is positioned on an internal surface of the lens cover 202. The first refractor 206 is a vertically extending prism that is moulded from a transparent plastics material having a refractive index higher than that of air.

The lamp assembly 200 includes a second light redirector in the form of a second refractor 208. The second refractor 208 takes the form of a series of horizontally extending prismatic features 211 moulded, machined or otherwise formed into an internal surface of the lens cover.

The lamp assembly 200 is configured such that light 210 provided by the LED light 204 is directed onto the first refractor 206. The first refractor 206 redirects the light 210 by refraction, such that at least a portion of the redirected light is repeatedly reflected along at least one curved surface of the lens cover 202.

In the embodiment of Fig. 4, some of this portion is also directed along a first light path 214. This light is totally internally reflected within the lens cover 202, reflecting off an external interface 216 and an internal interface 218 of the lens cover 202.

In the embodiment of Fig. 4, some of the portion is also directed along a second light path 220, and, instead of entering the lens cover 202, reflects repeatedly off the internal interface 218. The second light path 220 is within a gap 212 between the lenses 207/209 and the lens cover 202.

Light from the first light path 214 and second light path 220 bounces through and along, respectively, the lens cover 202 until it reaches the second refractor 208. The second refractor 208 redirects at least some of the reflected light from the first and second light paths so that it exits the lens cover 202 as shown.

By carefully selecting the relative positions and angles of the lens cover 202, LED light 204, first refractor 206 and second refractor 208, an angle (or range of angles) at which light exits the lens cover 202 may be optimised to meet particular requirements. For example, if the LED light 204 is for a parking light that must be visible at 45 degrees across the front of a car 222 (see Fig. 5) in which the headlamp assembly 200 is installed, then the relative positions and angles may be chosen such that at least some of the light exiting the lens cover 202 travels at more than 45 degrees to the axis of the car 222.

Optionally, a diffuser 224 is positioned adjacent the first refractor 206. The diffuser 224 takes a portion of the light from the LED light 204 and diffuses it as shown by first arrows 226. In the embodiment illustrated in Fig. 4, at least some of the light that is diffused has already been refracted by the first refractor 206. However, the skilled person will appreciate that the diffusor 224 may be positioned, and the headlamp assembly 200 configured, such that at least some of the light is diffused before refraction by the first refractor 206.

Although the embodiments are described with reference to a lens cover 202, the skilled person will appreciate that similar functionality may be attained using a lens (or lenses) rather than the lens cover. In that case, the redirected light portion from the first light redirector is directed behind one or more lenses (not shown) that cover one or more lights (such as headlights). A surface of the lens or lenses then acts to reflect the light from the first light redirector to the second redirector in the manner described above in relation to the lens cover 202. It will be appreciated that a lens cover may still be provided in such an embodiment.

The lens cover 202 (and lens, in any embodiment that uses lenses to redirect the light from the first light redirector) may be formed from any suitable transparent, partially transparent, or translucent material, such as glass or acrylic, or combination thereof. While in general it is anticipated that the lens cover or lens will be continuously curved in plan, the particular shape of the lens cover or lens may be chosen to suit a given application. For example the lens cover, or at least an inner or outer surface thereof, may comprise a series of planar surfaces, each abutting adjacent planar surface(s) at an oblique angle. The lens cover or lens may also be of composite construction, formed of two or more individual pieces.

The light source has been described as being LED-based, but may take the form of one or several LEDs, organic light emitting diodes (OLEDs), halogen lamps, incandescent lamps, high intensity discharge lamps, fluorescent lamps, any other suitable light source, or any combination thereof. Where required, the light source incorporates suitable light focusing elements, collimators or defocusing elements. These can include any suitable combination of reflectors (such as straight, curved, concave or convex mirrors), refractors (such as curved lenses, Fresnel lenses, and/or prisms), and any other element that redirects the primary light produced by the light source into a form suitable to direct the light towards the first light redirector.

The skilled person will understand that the term “light path” used herein is intended to include within its scope a spread of light that is not all moving at precisely the same angle. For example, a converging or diverging cone of light may still be considered as being on a “light path”. Such a spread of light may be intentional, for example such that only a portion of the light is higher than the critical angle for internal reflection, so that only some of the light is reflected.

Although the description refers to first light path 214 and second light path 220, the skilled person will appreciate that certain embodiments may only employ a single light path, which can be either the first light path 214 or the second light path 220.

Although the embodiment of Fig. 4 describes the use of refractors for the first and second light redirectors, the skilled person will appreciate that reflection and diffraction may also be used in each of the light redirectors, either alone or in combination with other types of light redirection mechanism. For example, instead of refraction with a prism, other embodiments may use a mirrored or partly mirrored surface as part of the first and/or second light redirector to reflect (ie, redirect) some or all incident light in a desired direction. The surface may be flat, or may be convex or concave to provide a focusing, collimating or defocusing function. Alternatively or in addition, yet other embodiments may use a diffractor such as a diffraction grating to redirect light. Refraction, where used, may be obtained by way of a prism, curved lens, Fresnel lens, or any other refracting structure, or a combination thereof.

Multiple layers of transparent, translucent or partly-transparent materials may be used to achieve desired light redirection characteristics. For example, two transparent materials having different refractive indices may be sandwiched together in known fashion.

One or more diffusors may also be used to diffuse at least some of the light incident on, or passing through, either or both of the first and second light redirectors. This diffused light may be used to provide a visually bright spot on or in the lamp assembly. This assists other road users and pedestrians in seeing the automobile.

Each of the first and second light redirectors may form part of the lamp assembly in any suitable manner. For example, either or both of the first and second light redirectors may be moulded as part of the lens cover or lens, machined into the lens cover or lens, or additively built onto the lens cover or lens. Either or both of the first and second light redirectors may be manufactured as a separate component that is assembled onto the lens cover or lens. Such assembly may involve, for example, adhesives, chemical- or temperature-based bonding, and/or mechanical fastening by way of one or more fasteners such as screws, clips, bolts or clamps.

In some embodiments, either or both of the first and second light redirectors may be mounted adjacent and/or separate from the lens cover or lens.

Although the first light redirector is described as being vertically extending, it will be appreciated that the first light redirector may take any suitable form, aspect ratio or orientation. The second light redirector may similarly take any suitable form, aspect ratio or orientation.

The invention may be used for one or several of the lights within a lamp assembly. For example, the embodiments above refer to a parking light, but the invention may equally be applied to an indicator light, a fog light, or any other sort of light that may be used in such light assemblies. Where the invention is applied to more than one such light within a particular assembly, the lights may share one or both of the light redirectors, or may have their own separate first and second light redirectors.

The skilled person will appreciate that other light redirectors may be used in addition to the first and second light redirectors.

Figs 6 to 8 show a different embodiment of a lamp assembly 200. In this embodiment, the light assembly 200 and, in particular, the first light redirector 206 have slightly different shapes in cross section compared to the embodiment of Figs 3 and 4. There is no diffuser 224 and no lenses 209/207. The light source takes the form of a light bulb 204 rather than an LED light.

The lamp assembly 200 of Figs 6 to 8 is configured, in this embodiment, to receive light from the bulb 204 in both direct and indirect forms. For example, third light path 230 shows light reflecting from a reflector into the first light redirector 206, while fourth light path 232 shows light coming directly from the bulb 204 into the first light redirector 206. Light on the third light path 230 and the fourth light path 232 is refracted by the first light redirector 206, such that at least some of it is redirected along the internal interface 218 of the lens cover 202 as described in relation to Fig. 4. An opaque element 228 provides a sharp cut-off edge for light entering the first light redirector 206.

In contrast to the embodiment of Figs 3 and 4, the embodiment of Figs 6 to 8 is configured and arranged such that no substantial component of the redirected light enters the interior of the lens cover 202 for total internal reflection within it. Instead, substantially all of the light reflects repeatedly off the internal interface 218.

As best shown in Fig. 6, the prismatic features 211 of the second refractor 208 are angled relative to the horizontal (when the lamp assembly is installed in the car). In this embodiment, the prismatic features 211 are moulded into the lens cover 202 on the internal interface 218. In cross section, the prismatic features 211 may take the form of a triangular saw tooth pattern. At least the tips of the prismatic features 211 are proud of the general curve of the internal interface 218, such that they capture at least some of the light that is being bounced along the internal interface 218. The captured light is then refracted out through the lens cover 202 as described above in relation to Fig. 4.

It will be understood that the third light path 230 and the fourth light path 232 do not show all potential light paths from the bulb 204 to the first light redirector 206. It will be appreciated, in particular, that some or all of a surface of the first light redirector 206 nearest the bulb 204 may receive direct and/or reflected light from the bulb 204.

The invention has been described in the context of a car headlamp assembly. The skilled person will appreciate that the invention also has application in other forms of automobile, such as trucks and motorbikes. The invention also has application in other types of lamp assemblies, such as tail-light assemblies.

Although the invention has been described with reference to a number of specific embodiments, the skilled person will appreciate that the invention may be embodied in many other forms.

Claims

1. A lamp assembly for a vehicle, the lamp assembly comprising: an at least partially transparent lens or lens cover; a first light redirector for redirecting at least some light produced by a light source, such that at least a portion of the redirected light is repeatedly reflected along at least one curved surface of the lens or lens cover; a second light redirector for redirecting at least some of the reflected light such that it exits the lens or lens cover, wherein at least some of the redirected light reflects repeatedly off an internal interface of the lens or lens cover.

2. The lamp assembly of claim 1, wherein the first light redirector comprises at least one reflector, diffractor, and/or refractor.

3. The lamp assembly of any preceding claim, comprising a diffuser for diffusing at least some of the light such that it exits the lens adjacent the first light redirector.

4. The lamp assembly of any preceding claim, wherein the first light redirector is disposed on, or is in contact with, the lens or lens cover.

5. The lamp assembly of any one of claims 1 to 3, wherein the first light redirector is moulded, machined or formed in or with, or otherwise forms an integral part of, the lens or lens cover.

6. The lamp assembly of any preceding claim, wherein the first light redirector is arranged such that, in use, when the lens is provided on a vehicle, the first light director extends generally vertically.

7. The lamp assembly of any preceding claim, wherein the second light redirector comprises at least one reflector, diffractor, and/or refractor.

8. The lamp assembly of any preceding claim, wherein the second light redirector is disposed on, or is in contact with, the lens or lens cover.

9. The lamp assembly of any one of claims 1 to 7, wherein the second light redirector is moulded, machined or formed in or with, or otherwise forms an integral part of, the lens or lens cover.

10. The lamp assembly of any preceding claim, wherein the light source is for a parking light or a turn indicator.

11. The lamp assembly of any one of claims 1 to 9, wherein the light source is for a tail light or a stop light.

12. The lamp assembly of any one of the preceding claims, configured such that, when installed in a vehicle, the light that exits the lens or lens cover includes a component that diagonally crosses a longitudinal axis of the vehicle.

13. The lamp assembly of claim 12, configured such that the component crosses the longitudinal axis of the vehicle at an angle of at least 45 degrees relative to the longitudinal axis.

14. The lamp assembly of any preceding claim, comprising the light source.

15. A headlamp comprising the lamp assembly of any one of claims 1 to 14.

16. A vehicle comprising the lamp assembly of any one of claims 1 to 14.