Vehicle lamp assembly

Abstract

 A vehicle lamp assembly comprises a light source (10) an outer element (18) formed of partially light transmitting material and a lens element (16) between the light source and the outer element. The outer element has alternate zones (20 and 22) of increased and reduced light transmission and the lens element (16) is arranged to concentrate light from the source 10 on to the zones of high light transmission.

Description

[0001] This invention relates to vehicle lamp assemblies of the type in which the colour of the light to be produced by the lamp cannot be readily perceived when the lamp is not illuminated. This reduces the risk that, in bright sunlight for example, the lamp assembly may appear to be illuminated, when in fact it is not.

[0002] According to the invention, a vehicle lamp assembly comprises a light source, an outer element having alternate zones of light transmission and light absorption and a lens element between the light source and the outer element having a respective lens formation for each zone of light transmission arranged to concentrate light from said source, thereon, wherein the outer element is formed of a partial-light transmissing material, so zones of light transmission comprise zones of reduced thickness compared to the zones of light absorption.

[0003] Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings in which:

Figure 1 is a schematic cross sectional view of a first embodiment of the invention,

Figures 2 and 3 are fragmentary schematic cross sectional views of the modifications to the embodiment shown in Figure 1,

Figure 4 is a schematic cross-sectional view of a second embodiment of the invention,

Figures 5 and 6 are schematic cross-sectional views of the modifications to the embodiment shown in Figure 4,

Figure 7 is a schematic cross sectional view of a third embodiment of the invention, and

Figures 8 and 9 are fragmentary schematic cross-sectional views of modifications to the embodiment shown in Figure 7.

[0004] Figure 1 shows a vehicle signalling lamp comprising a bulb 10 located at the focus of a parabolic reflector 12. Parallel light, such as the rays 14, from the reflector 12 is directed on to a distributor plate 16 which is made of a plastics material coloured in accordance with the required colour of the light from the lamp. Outside the distributor plate 16 is a cover plate 18 of neutral grey plastics material. The plate 18 has alternate thick zones such as the zone 20 and thin zones such as the zone 22. The nature of.' the material of the cover plate 18 is such that the proportion of incident light which is transmitted by the. thin zones 22 is greater than 25% while the proportion transmitted through the thicker zones 20 is less than 15%.

[0005] The distributor plate 16 has lens elements such as the element 24 formed thereon and arranged to direct the collimated light from the deflector 12 on to the thin zones 22 so that when the bulb 10 is illuminated the perceived colour from the cover 18 is that of the distributor plate 16.

[0006] On the other hand, when the bulb 10 is not illuminated, the only way in which the colour of the distributor plate 16 can be perceived is if incident light from outside -the lamp passes through the distributor plate 16 and is thence reflected out again. Only that part of the incident light which falls on the thinner zones 22 will reach the reflector at any significant level and since such light when reflected from the reflector 12 is essentially uncollimated, only about half of this light will fall on the thinner zones 22 so as to be perceivable from the outside.

[0007] Figure 2 illustrates a modification of the embodiment shown in figure 1 in which the cover plate 18 is replaced by a composite cover plate 30, the thicker zones 32 of which are formed of neutral grey material while the thinner zones 34 are formed of a clear plastics material. Similarly, in Figure 3, the cover plate 36; comprises a layer 38 of clear plastics material with projections 40 of neutral grey material secured to one surface thereof. With both of these modifications, a greater portion of light is transmitted but there is greater likelihood of the colour of the distributor plate 16 being perceived when the bulb 10 is off.

[0008] Figure 4 illustrates another embodiment of the invention, which is similar to that of the embodiment illustrated in Figure 1 except that the projections 46 forming the thicker zones of the cover plate 48 extend outwardly and are of generally triangular cross-section. Since the neutral grey plastics material is at its thickest at the apices of the triangles, the inner surface of the cover plate is relieved at 50 so as to save material.

[0009] Figure 5 illustrates a modification of the embodiment shown in Figure 6 having a cover plate 52 of clear plastic material with triangular cross-section projections 54 of neutral grey plastic material on the outer thereof. In Figure 6 the cover plate 56,. is predominently of neutral grey plastics material in the interstices between the projections.

[0010] It will be apparent that the embodiments illustrated in Figures 1 and 3 may have the thicker zones of the cover plate facing outwardly while the embodiment shown in Figures 4 to 6 may be modified by having such thickened zones facing inwardly.

[0011] Figure 7 illustrates a lamp which is basically similar to the lamp illustrated in Figure 1 except that its cover plate 60 has the zones of increased thickness extended to form baffles 62 projecting almost as far as the distributor plate 16.. As before the collimated light is concentrated by the lens formations 24 on to the thinner zones 64 between the baffles 62.

[0012] Figures 8 and 9 illustrate modifications to the embodiment shown in Figure 7. In Figure 8 the cover plate 70 comprises a layer 72 of clear plastics material with baffles 74 of grey plastics material mounted on the inner surface thereof. In Figure 9 the cover plate 76 is basically of grey plastics material but has clear plastic inserts 78 in the zones between the baffles 80.

[0013] In all the foregoing embodiments of the invention, the cover plates are of uniform cross-section, the alternate zones of differing cross-section being in the form of parallel strips. In alternative embodiments, the cover plates also have a similar cross-section to that illustrated in a plane perpendicular to that of the drawings, either the thicker zones or the thinner zones constituting isolated squares.

[0014] In any of the embodiments of the invention, the parabolic reflector 12 may be replaced or supplemented by a Fresnel collimator.

Claims

1. A vehicle lamp assembly comprising a light source, an outer element having alternate zones of light transmission and light absorption and a lens element between the light source and the outer element having a respective lens formation for each zone of light transmission and the range to concentrate light from said source thereon, characterized in that the outer element 18 is formed of partially light transmitting material.

2. A vehicle lamp assembly according to Claim 1, characterized in that the light material of the outer element (18) is of uniform transmissivity and the thickness of the outer element(18) is greater in the zones of light absorption (20) than in the zones of light transmission (22).

3. A vehicle lamp assembly according to Claim 2, characterized in that the transmissivity of the outer element (18) is such that the proportion of incident light which is transmitted by the thin zones (22) is greater than 25% whilst the proportion transmitted through the thicker zones (20) is less than 15%.

4. A vehicle lamp assembly according to Claim 1, characterized in that the material of the outer element (30, 36) has a higher transmissivity in the zones (34) of light transmission than in the zones (32, 40) of light absorption.

5. A vehicle lamp assembly according to Claim 4, characterized in that the outer element (30) is formed of a material of relatively high transmissivity with an interstices filled with material of lower transmissivity.

6. A vehicle lamp assembly according to Claim 4, characterized in that the outer element (36) comprises a layer of (38) of material of high transmissivity with projection (40) of a material of lower transmissivity secured to one surface thereof.

7. A vehicle lamp assembly according to any preceding claim, characterized in that the zones of low transmissivity of the outer element (60, 70, 76) are provided with baffles extending perpendicular thereto towards the lens element (16).

Drawing