GB2553337A

GB2553337A - Dome light assembly for a vehicle, cabin for a vehicle comprising a dome light assembly, and vehicle comprising a cabin with a dome light assembly

Info

Publication number: GB2553337A
Application number: GB1614917.1A
Authority: GB
Inventors: Gulick Eric; Lewis David; Nelson Ross
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2016-09-02
Filing date: 2016-09-02
Publication date: 2018-03-07
Also published as: GB201614917D0

Abstract

The invention relates to a dome light assembly 16 for a vehicle, suitable for a vehicle, comprising a lighting arrangement 18, 20, 22, 24 wherein the lighting arrangement comprises a first lighting device 30 for providing direct illumination of an interior of the vehicle and wherein the lighting arrangement further comprises a translucent optical element (26, see fig 2) covering the first lighting device. To provide a dome light assembly of this kind, by means of which dome light assembly an improved, consistent and especially relaxing illumination of an interior of a vehicle can be achieved, the lighting arrangement further comprises a second lighting device comprising a light source and an optical waveguide coupled to the light source and arranged to provide ambient illumination of the interior of the vehicle. The light assembly may be in a ribbon shape and may comprise two parallel optical waveguides extending along a respective side of the lighting element. The device may comprise more than one lighting device and at least two may abut each other to form a single continuous waveguide.

Description

(54) Title of the Invention: Dome light assembly for a vehicle, cabin for a vehicle comprising a dome light assembly, and vehicle comprising a cabin with a dome light assembly Abstract Title: Dome light assembly with direct and indirect lighting.

(57) The invention relates to a dome light assembly 16 for a vehicle, suitable for a vehicle, comprising a lighting arrangement 18, 20, 22, 24 wherein the lighting arrangement comprises a first lighting device 30 for providing direct illumination of an interior of the vehicle and wherein the lighting arrangement further comprises a translucent optical element (26, see fig 2) covering the first lighting device. To provide a dome light assembly of this kind, by means of which dome light assembly an improved, consistent and especially relaxing illumination of an interior of a vehicle can be achieved, the lighting arrangement further comprises a second lighting device comprising a light source and an optical waveguide coupled to the light source and arranged to provide ambient illumination of the interior of the vehicle. The light assembly may be in a ribbon shape and may comprise two parallel optical waveguides extending along a respective side of the lighting element. The device may comprise more than one lighting device and at least two may abut each other to form a single continuous waveguide.

Dome light assembly for a vehicle, cabin for a vehicle comprising a dome light assembly, and vehicle comprising a cabin with a dome light assembly

The invention relates to a dome light assembly for a vehicle, according to the preamble of patent claim 1, a cabin for a vehicle according to the preamble of patent claim 9, and a vehicle according to patent claim 10.

US 8,547,017 B2 discloses a vehicle dome and reading light assembly comprising a lighting device capable of generating plural light colours and two switches actuatable to cause the lighting device to generate light of a first and second colour and intensity. According to one embodiment there can also be two lighting devices assembled to an interior of the vehicle. To be able to generate light of different colours the light assembly may comprise an LED package, wherein the LED package comprises a plurality of LEDs of different colours.

DE 10 2006 006 364 A1 discloses a device for displaying visual information in a vehicle or aircraft interior. Using at least one light source of the device an imaginary Windows and/or horizon is displayed on a portion of a wall of the interior. In the process at least one light fitting is computer-controlled to adjust a luminous intensity and/or a colour and/or a colour gradient according to a daylight rhythm or a night light rhythm. According to one embodiment a beamer and a second light source can be provided, with the second light source used to brighten the display of the imaginary window or to visually reproduce natural daylight. There may also be multiple light fittings assembled to the wall emitting light in the direction of a ceiling of the interior.

US 4,628,417 discloses a combination dome/cargo lamp for a pickup truck. The dome/cargo lamp comprises an outer casing and an inner casing, wherein the outer casing is securable to a ceiling of a cab of the truck and wherein the inner casing is connected to the outer casing through pivot means. An electric bulb in the inner casing is covered by a lens that will in one position direct light into the cab and thereby function as a dome lamp. In a pivoted position the lens will direct light through a rear window of the cab and thereby function as a cargo lamp.

It is an object of the present invention to provide a dome light assembly of the kind indicated in the preamble of patent claim 1, by means of which dome light assembly an improved, consistent and especially relaxing illumination of an interior of a vehicle can be achieved. Further objectives of the present invention are to provide a vehicle cabin with a dome light assembly and to provide a vehicle with such a cabin.

These objects are solved by a dome light assembly having the features of patent claim 1, a cabin having the features of patent claim 9, and a vehicle having the features of patent claim 10. Advantageous embodiments with expedient developments of the invention are indicated in the dependent patent claims.

The dome light assembly according to the invention comprises a lighting arrangement.

The lighting arrangement comprises a first lighting device for providing direct illumination of an interior of a vehicle while the lighting arrangement is operated in an intended mounting position. The lighting arrangement further comprises a translucent optical element covering the first lighting device. The lighting assembly may comprise a plurality of lighting arrangements of which two or more may be assembled immediately adjacent or abutting each other or may be spaced apart. Preferably any distance or gap between two lighting arrangements should be small enough so that all lighting arrangements appear as a group or as part of the same lighting assembly. A preferred intended mounting position is a ceiling of the vehicle, especially the ceiling of a cabin of a truck. The optical element covering the first lighting device may for example be made from clear or partly clear plastic or glass and may function as a lens and/or to scatter light creating an optimal light cone for the particular environment or circumstance. Different areas or parts of the optical element may serve different functions and have different properties or optical characteristics.

To achieve or provide an improved, consistent and especially relaxing illumination of the interior of the vehicle the lighting arrangement further comprises a second lighting device comprising a light source and an optical waveguide or a light pipe coupled to the light source and arranged to provide ambient illumination of the interior of the vehicle provided the lighting arrangement is operated in the intended mounting position.

Within the meaning of the present invention direct illumination refers to light being emitted from the light source in the direction of the interior. The direct illumination should provide enough brightness, light intensity and illuminance to lighten at least parts of the interior or the cabin to allow a passenger of the vehicle fast, easy and comfortable recognition and visibility and flexible use of the cabin. In contrast to that the ambient illumination refers to a diffuse illumination or light. The ambient light is not emitted into the interior of the vehicle in a directed or focused light cone but rather provides a preferably uniform glow in a wide solid angle. The uniform glow provides a lower brightness and light intensity per area than the direct illumination. Overall the direct illumination serves as functional lighting to for example to enable the passenger or passengers of the vehicle to properly and comfortably see and discern details of the illuminated area or areas. The ambient illumination on the other hand serves as an environment lighting to light a background and to lower a contrast between areas lit by the direct illumination and areas not lit by the direct illumination. The ambient illumination or lighting also serves to set or create and improve a passenger or driver mood.

To provide ambient illumination the optical waveguide of the second lighting device may for example have a roughened, frosted, opaque and/or coloured surface. In addition the light source of the second lighting device may be arranged or positioned to emit light only into the waveguide and not directly into the volume of the interior of the vehicle. For example the light source may emit light in a direction parallel to the ceiling of the vehicle cabin.

The lighting assembly, the lighting arrangement and/or the first lighting device may comprise other parts or components not specifically mentioned here and/or may be connected to such parts or components. These parts or component may for example include casings, cabling, electric and/or electronic parts or equipment, switches and/or buttons and the like. In particular the first lighting device may comprise one or more light sources such as individual LEDs (light emitting diodes) or LED-arrays. More than one lighting device and/or lighting arrangement may be connected to the same lighting controller that controls a respective on- or off-state and/or other lighting functionality.

The present invention advantageously improves a general user experience as well as a mood, awareness and performance of the driver of the vehicle and thus also improves safety while operating the vehicle. Through the improved lighting or lighting conditions facilitated by the present invention a professional or commercial driver may also experience increased job satisfaction. The combination of direct and ambient illumination can advantageously illuminate more space and/or more surface area within the interior with lower contrast between light and unlit areas while requiring a minimum of required electrical energy or power to do so.

In an advantageous embodiment of the invention the lighting arrangement has a ribbonlike shape and the optical waveguide extends parallel along one long side of the lighting arrangement following a main direction of the lighting arrangement. In other words, the lighting arrangement has an elongated form with an extent in one direction being multiple times bigger than an extent in another direction, specifically in the two perpendicular directions. This should not be understood to mean the lighting arrangement always is or has to be straight or linear though. For example at least partly bent or curved shapes are also possible. As a result, the lighting arrangement can provide optimal illumination to a larger part of the vehicle interior with a minimum of required materials and weight. Another advantage is that light can be emitted from different angles and thus the occurrence of unwanted shadows can be reduced.

In another advantageous embodiment of the invention the lighting arrangement comprises two parallel optical waveguides each extending along a respective long side of the lighting arrangement. Preferably both waveguides may be coupled to their own light source but additionally or instead can in principle also be coupled to a common light source. Through the use of two parallel waveguides extending along different or opposite sides of the lighting arrangement, a uniformity of the ambient illumination can be improved with a minimum of additional installation space required.

In another advantageous embodiment of the invention the first lighting device is disposed in a central portion of the lighting arrangement and spaced apart from the optical waveguide. This layout facilitates easier and better heat management and also works to advantageously provide an even ambient illumination around the direct or main illumination.

In another advantageous embodiment of the invention the dome lighting assembly comprises a plurality of lighting arrangements each comprising a first and a second lighting device. As a result, the lighting assembly and its overall layout can be optimally adapted to the specific individual condition or situation to provide the best illumination. Furthermore a uniformity, evenness or consistency of the ambient illumination can be improved while reducing shadows and dark unlit areas or spots. Through the use of more than one lighting device the amount and evenness of the direct illumination can also be advantageously improved. Multiple spatially separated light sources advantageously allow for lower individual wattage, making the components cheaper and potentially reducing electrical load on an electrical system of the vehicle.

Preferably, at least two of the lighting arrangements are arranged abutting each other with the respective waveguides aligned to appear as a single continuous waveguide. In other words, the waveguide or waveguides of one lighting arrangement are aligned with the corresponding waveguide or waveguides of another lighting arrangement. Thereby improved aesthetics and a continuous, uniform ambient lighting can be achieved. At the same time, this modular structure of the lighting assembly enables a wide variety of different shapes and forms even with a limited number of different lighting arrangements. Thus the manufacturing of the lighting assembly and specifically of differently shaped or structured lighting assemblies is made easier and cheaper. Furthermore this modular approach allows for easy and optimal adaption of the lighting assembly to any specific vehicle and also enables easy and cheap replacement of a single damaged lighting arrangement without having to replace the whole lighting assembly.

Preferably, the lighting assembly comprises three lighting arrangements disposed to form a U-shape with two of the lighting arrangements extending parallel to each other and the third lighting arrangement connecting the other two. Here the two parallel lighting arrangements may be straight or they alternatively may be curved towards each other at one respective end. If the two parallel lighting arrangements are straight, the third lighting arrangement may preferably be curved at both ends to meet the two parallel ones. The waveguide or waveguides of the third, connecting lighting arrangement preferably extend all the way through the lighting arrangement. The respective waveguides of the two parallel lighting arrangements preferably extend to the respective end facing the third lighting arrangement but may be cut short on their respective other end. This enables a preferred continuous appearance of the waveguides of all three lighting arrangements while at the same time enabling a safe and protected termination or end of the lighting assembly at the ends or sides facing away from the third, connecting lighting arrangement. The U-shape may also be achieved or extended by combining more than three lighting arrangements. Advantageously the U-shape allows for a brightly illuminated central area underneath the lighting assembly where the light from all lighting arrangements combine or overlap. Compared to a single lighting arrangement or a more compact arrangement of several lighting arrangements, the proposed U-shape gives rise to a larger, more evenly lit area. Simultaneously the U-shape offers long inner and outer sides so that the overall combined length of the waveguides may be as big as possible, enabling an especially uniform, pleasant and relaxing ambient illumination.

Preferably the dome lighting assembly further comprises a fourth lighting arrangement disposed in front of an open side of the U-shape and spaced apart from the three lighting arrangements forming the U-shape, preferably separated by a gap less than 10 centimetres wide. Put in other words, the four lighting arrangements form a loop with two gaps between the ends of the two parallel lighting arrangements and the forth lighting arrangement. The gaps should preferably be small enough for the lighting assembly to be seen as a whole or a unit to create a harmonic visual appearance. The third lighting arrangement that connects the two parallel lighting arrangements may be substantially parallel to the fourth, separated lighting arrangement. An advantage of the described arrangement is the lighting assembly can be used to visually connect two parts of the interior of the vehicle and thus create a more harmonic and pleasant space. Another advantage is that the wiring and assembly of the lighting assembly is made easier especially if the interior - for example a cabin - and/or the ceiling of the vehicle is divided into two sections or constructed from two parts.

In addition to the dome lighting assembly a cabin for a vehicle, in particular for a truck, is provided as part of the present invention. The cabin or cab comprises a front operation portion and a rear sleeper portion and a dome lighting assembly assembled to a ceiling of the cabin. Herein the front operation portion is the area where for example a driver’s seat and a steering wheel or the like are located. The rear sleeper portion may for example contain a bunk or a resting area for the driver. To achieve or provide an improved, consistent and especially relaxing illumination of the cabin interior, the dome lighting comprises four lighting arrangements forming a gapped loop as described wherein the three lighting arrangements forming the U-shape are assembled to a ceiling of the rear sleeper portion of the cabin and separated from the fourth lighting arrangement by a curtain rail or the like. Correspondingly, the fourth lighting arrangement is assembled to a ceiling of the front operation portion of the cab.

In further addition to the dome lighting assembly a vehicle, in particular a truck, comprising a cabin according to the present invention is provided as part of the present invention.

The features, details and advantages mentioned in the present description and/or shown in the figures in relation to the dome lighting assembly, the cabin, and/or the vehicle according to the present invention may be mutually applied accordingly.

Further advantages, features, and details of the invention derive from the following description of a preferred embodiment as well as from the drawing. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respectively indicated combination but also in other combination or taken alone without leaving the scope of the invention.

The drawings show in:

Fig. 1 a schematic perspective view of a part of a ceiling of a truck cabin with a dome lighting assembly comprising four lighting arrangements assembled to it;

Fig. 2 a schematic perspective view of one of the lighting arrangements;

Fig. 3 a schematic perspective view of another one of the lighting arrangements;

and

Fig. 4 a schematic perspective view of still another one of the lighting arrangements.

In the figures the same elements or elements having the same function are indicated by the same reference signs.

Fig. 1 shows a schematic perspective view of a part of a ceiling or ceiling panel of a truck cabin. In particular, the cabin may be a cabin of a class 8 commercial vehicle according to the US truck classification based on the vehicle’s gross weight rating (GVWR). Within this classification system a class 8 vehicle is a heavy duty truck with a GVWR exceeding 14969 kg (33000 lb). Presently, the ceiling is comprised of two parts or sections, namely a rear ceiling panel 10 and a front ceiling panel 12. The former forms the ceiling of a rear sleeper portion of the cabin and the latter forms the ceiling of a front operation portion of the cabin. The rear ceiling panel 10 and the front ceiling panel 12 are divided by a curtain rail 14 extending in a vehicle transverse direction. Assembled to the ceiling is a dome lighting assembly 16 that presently comprises four lighting arrangements 18, 20, 22, 24. These could also be called lighting modules or lighting elements. All lighting arrangements 18, 20, 22, 24 may be straight or slightly curved to fit against the rear ceiling panel 10 or the front ceiling panel 12, respectively.

The lighting arrangements 18, 20, 22 are assembled to the rear ceiling panel 10 and arranged and substantially form a U-shape. Herein the at least substantially straight lighting arrangements 18 and 20 are disposed parallel to each other and are presently mirror images of each other. As such they are different parts and the lighting arrangement 5 cannot be mounted in the position of the lighting arrangement 20 and vice versa. The lighting arrangements 22 and 24 each have a different shape and form from the other lighting arrangements 18 and 20 wherein the lighting arrangement 22 has a substantially straight middle section and two end sections that are curved or bent by 90° towards the lighting arrangements 18 and 20, respectively. The lighting arrangement 24 on the other hand features a straight edge or side facing the other lighting arrangements 18, 20, 22 and thus has no curved or bent end sections except for rounded outer corners.

Overall the lighting assembly 16 shows a longitudinal symmetry with respect to an imaginary axis running along a vehicle longitudinal direction through a respective midpoint of the lighting arrangements 22 and 24.

Each lighting arrangement 18, 20, 22, 24 comprises a first lighting device 30 located in a respective central portion for providing direct illumination of the interior of the cabin. Presently the first lighting devices 30 comprise four LEDs arranged in a straight line extending parallel to a respective predominant direction of each lighting arrangement 18, 20, 22, and 24.

Additionally, each lighting arrangement 18, 20, 22, 24 comprises a second lighting device that in turn comprising an optical waveguide or light pipe for providing ambient illumination of the interior of the cabin. As part of the second lighting device there may also be provided another LED coupled to each waveguide and thus providing the light for the ambient illumination. More specifically the lighting arrangements 18, 20, 22 each comprise two straight waveguides extending spaced apart from and in parallel to the line of the first lighting device 30 and along the respective opposite outer and inner edges or sides of each lighting arrangement 18, 20, 22. The lighting arrangements 18, 20, 22 are aligned such that the waveguides are also aligned and thus the lighting arrangements 18, 20, 22 together have the appearance of a single continuous waveguide running along an inner side and a single parallel continuous waveguide along an outer side. The lighting arrangement 24 on the other hand only comprises a single waveguide extending along the partly curved outer or front side or edge nearest a front of the vehicle giving the whole lighting assembly 16 the appearance of a single waveguide or light pipe continuing around the outer circumference and only interrupted by the gaps cause by the curtain rail 14.

Alternatively, it might also be feasible to use tubular fluorescent lamps or the like as or as part of the second lighting devices as long as these lamps provide diffuse, ambient illumination.

Furthermore each lighting arrangement 18, 20, 22, 24 comprises a translucent casing or cover facing the interior of the cabin and mounted or abutting flush against the ceiling or a ceiling liner. This protects the lighting devices and prevents the misuse of the lighting assembly 16 as a handle as could be the case if the casing would only cover a part of the lighting assembly 16. The casing or cover is made up of two different parts or areas. The first part is an optical element 26 covering a central or middle area of each lighting arrangement 18, 20, 22, 24 including the first lighting devices 30 and following the shape of each lighting arrangement 18, 20, 22, 24 from one end to the other. The optical element 26 presently functions as a lens to shape a respective light cone or light distribution emitted from the first lighting devices 30. To achieve this, the optical element 26 may have specifically designed features, such as for example a corrugated or furrowed surface and/or a refractivity varying area by area. The second part or cover area 28 is arranged to either side of the optical element 26 and covers the optical waveguide or waveguides of each lighting arrangement 18, 20, 22, 24 providing an optimal yield or luminous efficiency of the ambient illumination.

Fig. 2 shows a schematic perspective view of the lighting arrangement 20. The optical element 26 covering the middle area as well as the second cover area 28 at least partly surrounding the optical element 26 are clearly visible. As described, the lighting arrangement 20 comprises a first lighting device 30 comprising four LEDs arranged in a straight line. Not shown are the two waveguides extending inside of the second cover area 28 in parallel to this line of LEDs and along the inner side 32 and the outer side 34 of the U-shape shown in Fig. 1. One end section of the lighting arrangement 20 - facing away from the lighting arrangement 22 - is terminated by the second cover area 28, while the other, opposite end section 36 is not. Instead, the end section 36 features an open face with the two waveguides extending to the very end.

Fig. 3 shows a schematic perspective view of the lighting arrangement 22. The middle section is at least substantially straight while the end sections are bent or curved by 90° in a main extension plane of the lighting arrangement 22 and the whole lighting assembly 16. Thus the lighting arrangement 22 has two open end faces 38 and 40 where the lighting arrangements 18 and 20 abut in the complete lighting assembly 16 as shown in Fig. 1. Similar as with the lighting arrangement 20, the two waveguides of the lighting arrangement 22 also extend along the inner side 32 and the outer side 34 but instead of being straight they follow the curves or C-shape of the lighting arrangement 22. Since the two waveguides also extend right to the end faces 38 and 40 - that are neither covered by the optical element 26 nor by the second cover area 28 - they, together with the corresponding two waveguides of the lighting arrangement 20, may form two seemingly continuous waveguides.

Fig. 4 shows a schematic perspective view of the lighting arrangement 24. The lighting arrangement 24 also comprises a first lighting device 30 covered by an optical element 26, and a second cover area 28. In contrast to the other lighting arrangements 18, 20, 22, the lighting arrangement 24 features only one waveguide extending along the outer edge or side 34 and covered by the second cover area 28. The waveguide follows the shape of the lighting arrangement 24 but does not extend to the very end of the lighting arrangement 24 at each end section 42. Similar to the covered end section of the lighting arrangement 20 opposite the open-face end section 36, both end sections 42 and indeed the entire inner side 32 of the lighting arrangement 24 are covered or terminated by the translucent casing or cover. Since there is no second waveguide at the inner side 32 of the lighting arrangement 24, the end sections 42 and the inner side 32 may be covered or terminated by the optical element 26, the second cover area 28, or in some other way.

Not shown in any of the figures is an electric or electronic control unit or control circuit for controlling the first lighting devices 30 and the second lighting devices. Such a control unit may for example comprise a microcontroller and a memory device equipped with the necessary code for any implemented or provided controlling and lighting functions.

From a user side the lighting assembly 16 may for example be controlled or operated by means of a lighting control that may comprise a switch, a button, or an array or arrangement of switches and/or buttons or the like coupled or connected to the control unit, the lighting assembly 16, or the individual lighting devices.

Preferably, an arrangement or set of three buttons, in particular rocker buttons, and a corresponding light control scheme are provided wherein the first lighting devices 30 of the lighting arrangements 18, 20 and 22 combined are operable by a first button, the first lighting device 30 of the lighting arrangement 24 is operable by a second button, and the second lighting devices, that is, the ambient illumination, of all lighting arrangements 18, 20, 22, 24 combined are operable by a third button.

A set of lighting control buttons may preferably be located or arranged on a dashboard of the vehicle, in the rear sleeper portion of the cabin, or both. Especially if there are two bunks, for example a lower and an upper bunk, in the rear portion of the cabin, several sets of buttons may be provided. Advantageously, one set of buttons would be located within reaching distance from the lower bunk and another set would be located within reaching distance from the upper bunk. Alternatively or additionally other sets of buttons may be provided in different areas or parts of the cabin and/or the vehicle. It could also be possible to provide a remote control option for controlling or operating the lighting assembly 16. Specifically it could be possible to allow controlling or operating the lighting assembly 16 via a portable mobile electronic device, such as a smartphone. Overall, multiple sets of buttons and/or ways to control the illumination can advantageously increase user convenience and a user experience.

To make describing the preferred control scheme easier, hereinafter “rear dome light” refers to the jointly controlled first lighting devices 30 of the lighting arrangements 18, 20, and 22, “front dome light” refers to the first lighting device 30 of the lighting arrangement 24, and “ambient light” refers to the jointly controlled second lighting devices of all lighting arrangements 18, 20, 22, and 24.

The preferred control scheme is intended and designed to improve the user experience and to match practical real world scenarios. All three buttons start from a normal or neutral resting position. Starting from a situation with all lights or light sources turned off, a momentary depression and immediate release of the first button causes the rear dome light to ramp from the off-state to the on-state with full capacity or brightness reached after or within two seconds. If, instead, the first button is depressed and held in its depressed state, the rear dome light would ramp to their full on-state over five seconds. Starting with the rear dome light turned on, a momentary depression and immediate release of the first button causes the rear dome light to turn off.

All buttons also allow for dimming the respective lights and setting various dimming levels or various levels of dimmed brightness between the off-state and the full-capacity onstate. In other words, since it takes five seconds for the rear dome light to reach their full brightness from the off-state when the first button is depressed and held, a release of the first button not immediately after depressing it but before the five seconds have elapsed, would cause the rear dome light to stay at the currently reached brightness or illumination level. Correspondingly, if the rear dome light is at full brightness and the first button is depressed and held, the rear dome light is dimmed or ramped down to its off-state over 5 seconds. If the first button is released not immediately after depressing it but before the five seconds have elapsed, the rear dome light will stay or remain at the reached dimmed or reduced brightness level.

If the first button is depressed and held while the rear dome light is at a dimmed brightness level between zero (off-state) and full or complete on, then the brightness may be reduced or increased in continuation of the direction of the last brightness-change. In other words, if the rear dome lights were dimmed from their full on-state to for example half brightness, then the next time the first button is depressed and held the dimming is continued and the brightness of the rear dome light is ramped further down. In this case, the rate of the reduction or increase in brightness corresponds to the rate of five seconds for a full change between zero and full brightness.

Correspondingly, a momentary depression and immediate release of the first button while the rear dome light is at a dimmed brightness level or dimmed brightness setting, continues the reduction or increase in brightness of the last dimming action. In this case however, the rate of the change in brightness corresponds to two seconds for full change between zero and full brightness.

This advantageously enables the user to set a desired brightness, while always guaranteeing a comfortable change rate of change in brightness. Thus an uncomfortable and potentially startling or even dangerous instant switch between full darkness and full brightness or vice versa is avoided. This increases safety of operation of the vehicle since the eyes of the user always have at least minimal time to adapt to a change in brightness or illumination. Otherwise, a momentary failure or disruption in the user’s ability to see his surroundings may occur.

Correspondingly, the same settings, functions and operation may be taken or carried out for the front dome light using the second button, and for the ambient light using the third button. This means, that the rear dome light, the front dome light, and the ambient light may be controlled or operated independently from each other in the same ways via their respective buttons.

Additional functionality, however, is provided regarding the rear and front dome light. Opening a door of the vehicle, in particular a cabin door, causes the rear and front dome lights to ramp to full brightness and to ramp off again after fifteen minutes (plus or minus ramp times) while a door of the vehicle is still open. If in the meantime all doors of the vehicle are closed, the rear and front dome lights ramp off thirty seconds (plus or minus ramp times) after the last door is shut. This automatic functionality for the rear and front dome lights may be overridden by operating the respective corresponding button. For example, the lights can be turned off via the corresponding buttons even before the automatic shut-off timer has expired. As another example, the automatic shutting-off of the lights thirty seconds after all doors are shut may be prevented by manually operating the corresponding button or buttons.

At least one of the three buttons, preferably the first button, may provide further additional functionality such as an all-lights-off function. This could for example be implemented in such a way as to turn off all currently on or dimmed lights - the front dome light, the rear dome light, and the ambient light - by performing a double momentary press of the first button. In other words, momentarily depressing the first button, immediately releasing it, and then momentarily depressing and immediately releasing it again.

Certainly different control schemes and arrangements are possible. For example it is possible to include a fourth switch or button to allow for independent control of the front and rear ambient illumination. This is however not part of the preferred embodiment and would require different or updated software control parameters.

It is to be understood that the assignment between a specific button and a specific light could also be configured in different ways.

22, 24

List of reference signs

Rear ceiling panel

Front ceiling panel

Curtain rail

Dome light assembly

Lighting arrangements

Optical element

Second cover area

First lighting device

Inner side

Outer side

End section (of lighting arrangement 6) End faces (of lighting arrangement 22) End sections (of lighting arrangement 24)

Claims

1. Dome light assembly (16) for a vehicle, comprising a lighting arrangement (18, 20, 22, 24) wherein the lighting arrangement (18, 20, 22, 24) comprises a first lighting device (30) for providing direct illumination of an interior of the vehicle provided the lighting arrangement (18, 20, 22, 24) is operated in an intended mounting position and wherein the lighting arrangement (18, 20, 22, 24) further comprises a translucent optical element (26) covering the first lighting device (30), characterised in that the lighting arrangement (18, 20, 22, 24) further comprises a second lighting device comprising a light source and an optical waveguide coupled to the light source arranged to provide ambient illumination of the interior of the vehicle provided the lighting arrangement (18, 20, 22, 24) is operated in the intended mounting position.

2. Dome light assembly (16) according to claim 1, characterised in that the lighting arrangement (18, 20, 22, 24) has a ribbon-like shape and the optical waveguide extends parallel along one long side (32, 34) of the lighting arrangement (18, 20, 22, 24) following a main direction of the lighting arrangement (18, 20, 22, 24).

3. Dome light assembly (16) according to any one of the preceding claims, characterised in that the lighting arrangement (18, 20, 22) comprises two parallel optical waveguides each extending along a respective long side (32, 34) of the lighting arrangement (18, 20, 22).

4. Dome light assembly (16) according to any one of the preceding claims, characterised in that the first lighting device (30) is disposed in a central portion of the lighting arrangement (18, 20, 22, 24) and spaced apart from the optical waveguide.

5. Dome light assembly (16) according to any one of the preceding claims, characterised in that the dome light assembly (16) comprises a plurality of lighting arrangements (18, 20, 22, 24) each comprising a first (30) and a second lighting device.

6. Dome light assembly (16) according to claim 5, characterised in that at least two of the lighting arrangements (18, 22; 20, 22) are arranged abutting each other with the respective waveguides aligned to appear as a single continuous waveguide.

7. Dome light assembly (16) according to claim 5 or 6, characterised in that the lighting assembly (16) comprises three lighting arrangements (18, 20, 22) disposed to form a U-shape with two (18, 20) of the lighting arrangements (18, 20, 22) extending parallel to each other and the third lighting arrangement (22) connecting the other two (18, 20).

8. Dome light assembly (16) according to claim 7, characterised in that the lighting assembly (16) further comprises a fourth lighting arrangement (24) disposed in front of an open side of the U-shape and spaced apart from the three lighting arrangements (18, 20, 22) forming the U-shape, preferably separated by a gap less than 10 centimetres wide.

9. Cabin for a vehicle, in particular a truck, wherein the cabin comprises a front operation portion and a rear sleeper portion and a dome light assembly (16) assembled to a ceiling (10, 12) of the cabin, characterised in that the dome light assembly (16) is a dome light assembly (16) according to claim 8 wherein the three lighting arrangements (18, 20, 22) forming the U-shape are assembled to a ceiling (10) of the rear sleeper portion of the cabin and separated from the fourth lighting arrangement (24) by a curtain rail (14) or the like.

10. Vehicle, in particular a truck, comprising a cabin according to claim 9.

Intellectual

Property

Office

Application No: GB1614917.1 Examiner: Mr Robin Jones