GB2343214A

GB2343214A - Vehicle sunroof having an artificial electric light source arranged between inner and outer panes

Info

Publication number: GB2343214A
Application number: GB9924383A
Authority: GB
Inventors: Robert Lindermaier
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 1998-11-02
Filing date: 1999-10-14
Publication date: 2000-05-03
Anticipated expiration: 2019-10-14
Also published as: DE19850371A1; GB9924383D0; GB2343214B

Abstract

A vehicle sunroof for controlling the lighting characteristics inside a vehicle both during the day and at night has an electric light source (7) located between a variable transparency inner pane (5), preferably liquid crystal, and an outer pane (3) made of safety glass. Preferably, several oppositely located electric lights are provided and include anti-dazzle devices (9) which guide the light horizontally. A movable panel (8) may also be provided between the light source (7) and the outer pane (2) to prevent artificial light passing through the outer pane. The inner surface of this panel is preferably designed to reflect artificial light back into the vehicle interior. The inner pane preferably includes transparent edge covering (10) and the outer pane may be designed to protect the inner pane from excessive infra-red radiation and overheating.

Description

2343214 Vehicle roof extension with a variable trahsparency pane The

present invention relates to a vehicle roof extension with an at least partly transparent pane having variable transparency inserted into a roof cut-out on the interior side of the vehicle roof and the side of the roof cut-out on the exterior of the vehicle roof is covered by an outer pane preferably made from safety glass.

Previously proposed constructions are described in DE 195 29 737 C1 and especially in DE 197 23 596 C1. The latter paper shows a vehicle roof extension of this construction. By the use of a pane having variable transparency very different light incidence conditions can be adjusted in the inside of the vehicle during daylight, in accordance with the wishes of the vehicle occupant(s). To this end only the light transmission of the pane mentioned has to be appropriately altered, which can be effected especially by the application of a suitable electrical voltage to a suitably constructed pane. For instance, the variable transparency pane can be made with electro-chrome. As well as this, so-called LC panes are known, working on the liquid crystal principle, which permit an unimpeded light transmission with the application of an electrical voltage and are thus clearly transparent, whereas without an applied electrical voltage they are diffusively scattering, permitting only a diffused light transmission and are thus only partly transparent.

2 By night, on the other hand, when no or only very little ambient light is present, the possibilities of variation with such a variable light transmitting pane are naturally very small.

An aim of the present invention is to provide measures by which the light conditions in the inside of a motor vehicle, whose roof cut-out is at least partly provided with a variable transparency pane, can be adapted to the wishes of the vehicle occupant(s) in an especially comfortable manner.

Accordingly, the present invention is directed to a vehicle roof extension as described in the opening paragraph of this patent specification, in which at least one electrical light source is provided in a space between the outer pane and the variable transparency pane.

Advantageously, in edge areas of the roof cut-out opposite to each other, an electrical light source is provided in each area and extending over some of the length of the areas.

Preferably, an anti-dazzle device substantially permitting the passage of light horizontally, is provided between the outer pane and the variable transparency pane, and in front of the light source.

In a preferred embodiment, beneath the outer pane and above the light source a movable roof or similar is provided, with the aid of which the penetration of light through the outer pane can be inhibited.

3 Advantageously, in which the underside of the movable roof f acing the variable transparency pane is made at least partly light reflecting.

Preferably, an edge covering of the roof cut-out which faces the vehicle interior is provided, and is made transparent, at least in sections.

Advantageously, the variable transparency pane comprises a liquid crystal pane and the outer pane comprises an inf rared protecting pane.

According to the present invention at least one light source is provided behind the variable transparency pane, relative to the vehicle interior. Especially at night an extremely pleasant interior light may be generated if the variable transparency pane is set to diffused, or attenuated transparency. By the use of the variable transparency pane in combination with the arrangement of at least one light source the roof construction according to the present invention is distinguished from previously proposed constructions such as DE 195 29 737 C1.

with regard to the optimum sight conditions for the vehicle driver, he should himself preferably sit at night in a darkened space. It is therefore proposed that either this lighting be made possible only in a stationery vehicle, or to provide that the variable transparency pane can be lit from behind, away from the vehicle driver's sitting position, for 4 instance especially in the rear part of an otherwise normal four-seater passenger motor vehicle.

An example of a vehicle roof extension according to the present invention will now be described with reference to the 5 accompanying drawing, in which:

Figure I shows a partial transverse cross section of a vehicle roof frame incorporating the present invention.

The roof frame 1 of a passenger motor vehicle borders a roof cut-out 2. Towards the exterior of the vehicle the roof cut-out 2 is covered by a transparent outer pane 3 (with the exception of its rim area). Towards the vehicle interior 4, in the roof cut-out 2 an at least partly transparent pane 5 is inserted, whose transparency can be changed, especially by the application of an electrical voltage, and which in the present description is designated throughout as a variable transparency pane 5.

There is a space 6 between the outer pane 3 and the variable transparency pane 5 in which there is provided, preferably in the rim area of the roof cut-out 2, an electrical light source 7, which extends over some length of the rim area. Preferably this light source 7, which may be a fluorescent tube, extends, as does the pane 5, in the longitudinal direction of the vehicle preferably over its rear saloon area. It is preferred also to provide, as well as the light source 7 shown here and positioned for instance, relative to the forward direction of travel of the vehicle, on the left rim area of the roof cut-out 2, a further light source 7 of the same type in the opposite rim area of the roof cut-out 2. Further, it is possible to provide similar light sources also in the region of a front and/or rear rim of the roof cut-out 2.

with the aid of this light source 7 it is possible to achieve in the corresponding area of the vehicle interior 4 (i.e. in the rear saloon area) an especially pleasant, soft illumination, especially at night, if the variable transparency pane 5 is switched to a diffuse or less transparent characteristic. In order to prevent undesirable radiation of the light from the light source(s) 7 to the outside environment, a movable roof 8 or similar is provided and brought into a covering position at least covering the pane 5, below the outer pane 3 and above the light source(s) 7. Especially during the day, however, it should be possible to put this movable roof 8 into a different position to permit the sunlight to pass through the outer pane 3 into the vehicle interior 4.

To increase the light yield in the vehicle interior 4 when the light source 7 is in operation, the underside of the movable roof 8, facing the variable transparency pane 5, can be made at least partly light-reflecting. Thereby the movable roof 8 can be shaped such that an even light distribution over the whole of the transparent pane 5 lying beneath it is achieved. Furthermore it is possible, as shown here, to 6 provide in front of the light source 7 an essentially horizontal, relative to the space 6, light transmitting antidazzle device 9. With a suitable construction this anti-dazzle device 9 inhibits radiation from the light source 7 from dazzling the occupants of the rear compartment, especially with the pane 5 fully transparent, when it is not switched to a diffuse characteristic. For this purpose the anti-dazzle device 9 can comprise, for instance, several suitably shaped plates parallel to each other, and arranged to run horizontally.

There is also provided an edge covering 10 of the roof cut-out 2, which faces the vehicle interior 4, with the aid of which the variable transparency pane 5 is retained in a suitable manner. This edge covering 10 comprises thereby an edge part 10a, which has a groove to accept the pane 5, as well as, at least in sections, a so-called edge under-glass 10b, which screens off the edge part 10a from the vehicle interior 4. The latter is, as is the edge part 10a in the same sections, made transparent, so that light emitted from the light source 7, at least in some regions, can reach the vehicle interior 4 directly, so as, for instance, to function as a reading light for the back seat passengers. This edge covering should also be readily removable, so as, for instance, to allow replacement of a no longer functioning light source 7 or to allow cleaning of the rear side of the variable transparency pane 5.

7 As already stated, the variable transparency pane 5 can be constructed using various physical principles; it is however preferred to make the variable transparency pane as a liquid crystal pane, which by the application of an electrical voltage can be switched either to a clear transparent condition or to a diffuse characteristic. Amongst other reasons, because such an LC pane is only able to work up to a certain limiting temperature, the outer pane 3 is not only made, as normal, of safety glass, but also preferably as an infra-red protecting pane or as a glass pane which reflects at least part of the infra-red radiation of sunlight. However, this can, in addition to a multiplicity of other features, be constructed in a different fashion from the example of construction shown, without departing from the scope of the present invention.

8

Claims

1. A vehicle roof extension with an at least partly transparent pane having variable light transparency inserted on the interior side of a vehicle roof in a roof cut-out, and the outer side of the roof cut-out being covered by an outer pane especially made of safety glass, in which at least one electrical light source is provided in a space between the outer pane and the variable transparency pane.

2. A vehicle roof extension according to Claim 1, in which, in edge areas of the roof cut-out opposite to each other, an electrical light source is provided in each area and extending over some of the length of the areas.

3. A vehicle roof extension according to Claim 1 or Claim 2, in which an anti-dazzle device substantially permitting the passage of light horizontally, is provided between the outer pane and the variable transparency pane, and in front of the light source.

4. A vehicle roof extension according to any preceding claim, in which beneath the outer pane and above the light source a movable roof or similar is provided, with the aid of which the penetration of light through the outer pane can be inhibited.

9

5. A vehicle roof extension according to Claim 4, in which the underside of the movable roof facing the variable transparency pane is made at least partly light reflecting.

6. A vehicle roof extension according to any preceding claim, in which an edge covering of the roof cut-out which faces the vehicle interior is provided, and is made transparent, at least in sections.

7. A vehicle roof extension according to any preceding claim, in which the variable transparency pane comprises a liquid crystal pane and the outer pane comprises an infra-red protecting pane.

8. A vehicle roof extension substantially as described herein with reference to the accompanying drawing.