Improvements to vehicle lamps

Abstract

 in a vehicle lamp having a light source (1) and which is capable of producing a coloured light, a grid member (5) is incorporated between a filter (4) and a light-transmitting cover (3), the elements (6) of the grid member presenting surfaces (6a), (6b), (6c) and (6d) which are out of line with the direction (8) of the light, before it passes through the filter such that the grid member reflects external light entering the lamp to a large degree thereby to impede such external light from impinging on the light source or filter, the coloured light being directed by an optical pattern on the filter through the openings (7) in the grid when the lamp is operating.

Description

[0001] This inventicnrelates to vehicle lamps, primarily direction indicator lamps although it is also applicable to lamps which it is desired to present an appearance or colour effect different from the colour which the lamp must show when it is operating.

[0002] Thus a demand exists for a front direction indicator lamp for mounting adjacent to a headlamp such that, when not operating, its visual appearance is complementary to that of the headlamp, that is it presents a bright clear- glass, uncoloured appearance. The lamp, when operating as a signal lamp, must show an amber light complying with current regulations. A demand also exists for the rear cluster of lamps in the vehicle to have a uniform visual appearance, e.g. smoky black yet in the case of rear direction indicator and other rear lamps such as brake lamps, they should, when operating, show respectively amber and red lights.

[0003] The present invention has for an object to provide a lamp of the kind above referred to which complies with legal requirements and which controls external white light which may enter the lamp and be reflected out again in such a manner that the normal eye responses are unable to detect any appreciable colour within the lamp.

[0004] Accordingly, the present invention consists in a vehicle lamp which is capable of producing a coloured light when the lamp is operating and having a light transmitting cover, a light source, a grid member incorporated between the cover and the light source, a filter disposed between the grid member and the light source and provided with an optical pattern to concentrate the coloured light through the openings in the grid member, characterized in that the elements of the grid member are shaped and present surfaces which are out of line with the direction of the light before it passes, during operation of the lamp, through the filter, whereby external light entering the lamp is reflected from more than one of the surfaces of at least some of said grid elements thereby to reflect such external light to a large degree and impede it from impinging on the filter or the light source.

[0005] In order that the invention may be more readily understood reference will now be made to the accompanying drawings, in which:

Fig. 1 is a diagrammatic cross-section of a front direction indicator lamp,

Fig. 2 is a plan view of a grid member, suitable for the lamp of Fig. 1,

Fig. 3 is an end view partly in section of the grid member of Fig. 2,

Fig. 4 is a plan view of a filter suitable for the lamp of Fig. 1, and

Fig. 5 is a partial section showing an alternative shape of the elements of the grid member to an enlarged scale.

[0006] The lamp shown comprises a white light source 1, light from which is focussed by a reflecting surface 2 and passes out of the lamp through a light-transmitting cover 3 which in this embodiment constitutes an external lens having an optical pattern which distributes the reflected light as required. As this cover 3 has to be glass clear, the white light source has its colour converted by being made to pass through an amber filter 4 constituting a lens member. Between this filter 4"-and the cover 3 a grid member 5 is located and which comprises a plurality of shaped elements 6. An optical pattern consisting of a plurality of concentrically arranged lens elements on the amber filter 4 concentrates light through the (openings) gaps 7 in the grid. This amber light is then distributed as required through the external lens.

[0007] The grid member 5 is so designed that the majority of external light A entering into the lamp through the lens 3 is reflected out again as indicated by B, by the surfaces 6a, 6b,6c and 6d of the shaped elements 6 of the grid. The grid elements 6 of the grid member are shown in Figs. 1, 2 and 3 as having a diamond-shaped cross-section and being of circular form in plan and are concentrically arranged. The grid elements 6 are held together by means of radially extending webs 9 which are integral therewith and with a surround 10. It should be appreciated that the inner side of the surround presents two surfaces corresponding to and similarly shaped and positioned to the surfaces 6b and 6c of the grid elements 6. The filter 4 is mounted to the grid member 5 by means of a central projection 11 thereon fitting in a central aperture 12, the filter engaging with an abutment 13 to hold the filter at the correct optical distance from the gaps 7 in the grid member. As can be seen from . Fig. 1, when considered in cross-section, the front and rear edges of the grid elements 6 are ir line with the direction 8 of the light and the side edges of the adjacent grid elements face each other across the gaps.

[0008] As shown in the drawings, the surfaces 6a, 6b, 6c and 6d are out of line with the direction of the light from source 1 as shown by the arrow heads 8 before it passes through the amber filter 4. This arrangement enables external light A entering the lamp to be reflected from more than one of at least some of the surfaces 6a, 6b, 6c and 6d and out again as indicated at B. Obviously some external light must pass through the gaps in the grid and can be reflected out again through these gaps. However as the surface area of the grid member can be made at least twice that of the gaps, less than 50% of the light entering at normal to the lamps will reach the amber filter. This ratio will reduce proportionally as the direction of entry deviates from the normal and at about 45° angle of entry reduces to zero and remains at zero beyond this angle.

[0009] Therefore the ratio of total external light entering the lamp to the light reaching the amber filter will be very low. Further, that external light which does reach the amber filter and is reflected back has to pass through the gaps in the grid. As there is a loss of light at any reflection stage, and some of this light must be reflected several times before "escaping" through the gaps, and this also includes any light which may pass through the filter onto the reflector and out again, the proportion of external light entering the lamp, being converted to yellow light , and being reflected out again through the external lens as yellow light, could, by careful design of the optical-grid system, be of such low value compared with the bright reflected light, that this yellow light is virtually undetectable by the normal eye responses.

[0010] The optics on the filter and the pattern of the grid member may be of annular, linear or other desired form provided that the reflecting surfaces of the grid member are out of line with the direction of the light before it passes through the filter.

[0011] In a modification the light source 1 may have an amber colour, in which case the filter 4 may be of clear or white opaque glass. Alternatively, the reflector may be coloured.

[0012] In another modification, the filter 4 may be replaced by a Fresnel lens which concentrates the transmitted light in bright and dark rings, the grid elements being positioned in front of the dark areas.

[0013] In a further modification the cover 3 need not constitute an external lens but may be just light transmitting.

[0014] The grid member may have a bright metallized, black or other coloured surface to provide a neutral or coloured look. The filter could be red in the case of a rear lamp; such as a brake lamp.

[0015] At least some of the grid elements may be of different shapes and sizes and arranged in any suitable way to obtain the desired result. Grid elements may have more than four reflecting surfaces when considered in cross-section and one or more of the reflecting surfaces may be curved. For example, in Fig. 5 two adjacent surfaces 6a, 6b of the grid elements 6 are inwardly curved whereas the remaining surfaces 6c and 6d are planar.

[0016] The concentric arrangement of the grid elements can be in line or out of line with the focal axis of the light source and reflector. Instead of being circular the grid elements may be of other closed form such as rectangular, symmetrically or otherwise arrangedone inside the other.

Claims

1. A vehicle lamp which is capable of producing a coloured light when the lamp is operating and having a light transmitting cover, a light source, a grid member incorporated between the cover and the light source, a filter disposed between the grid member and the light source and provided with an optical pattern to concentrate the coloured light through the openings in the grid member, characterized in that the elements (6) of the grid member (5) are shaped and present surfaces (6a), (6b), (6c) and (6d) which are out of line with the direction (8) of the light before it passes, during operation of the lamp, through the filter (4), whereby external light entering the lamp is reflected from more than one of the surfaces of at least some of said grid elements thereby to reflect such external light to a large degree and impede it from impinging on the filter or the light source (1).

2. A vehicle lamp as claimed in claim 1, characterized in that at least some of said surfaces (6a, (6b), (6c) and (6d) of the grid elements (6) are curved when considered in cross-section.

3. A vehicle lamp as claimed in claim 1 or 2, characterized in that at least some of'the grid elements (6) when consid- ered in cross-section have-at least four sides.

4. A vehicle lamp as claimed in any one of claims 1 to 3, characterized in that at least some of the grid elements (6) are of different shapes.

5. A vehicle lamp as claimed in any one of claims 1 to 3, characterized in that the grid elements (6) are generally of diamond-shaped configuration when considered in cross-section.

6. A vehicle lamp as claimed in any one of claims 1 to 5, characterized in that two oppositely facing edges of each of said grid elements(6)between respective ones of said surfaces, when considered, in cross-section are in line with the direction of the light before it passes, during operation of the lamp, through said filter (4).

7. A vehicle lamp as claimed in any one of claims 1 to 6, characterized in that two edges of each two adjacent grid elements (6) face each other, said edges being between respective ones of said surfaces.

8. A vehicle lamp as claimed in any one of claims 1 to 7, characterized in that the grid elements (6) are of closed form when considered in plan and are arranged one inside the other.

9. A vehicle lamp as claimed in claim 8, characterized in that the grid elements are held together by means of outwardly or inwardly extending webs.

10. A vehicle lamp as claimed in any one of claims 1 to 9, characterized in that at least some of the grid elements (6) are of different sizes.

11. A vehicle lamp as claimed in any one of claims 1 to 10, characterized in that the filter (4) is mounted to the grid member (5) by means (11, 12).

12. A vehicle lamp as claimed in any one of claims 1 to 11, characterized in that the grid member (5) has a surface area which is at least twice that of the openings (7) therein.

13. A vehicle lamp as claimed in any one of claims 1 to 12, characterized in that the filter (4) is a Fresnel lens for concentrating the transmitted light in bright and dark rings, the openings (7) in the grid member (5) being positioned in front of the light areas.

Drawing