GB2334326A - Reflector for vehicle marker lamp - Google Patents

Abstract

A marker lamp 10, such as an auxiliary lamp for a vehicle, comprises an elongate reflector 16, a light source 18 and a lens 14, wherein the central area 16a1 of the reflector has a parabola shape with a focal point in the neighbourhood of the light source and reflects light from the light source forwards, while at least one peripheral area of the reflector is composed of a second surface 16a2, continuing directly with the first surface, to reflect light from the light source into the four comers, the or each second surface having a first cross section extending in the longitudinal direction with a radius of curvature larger than that of the central paraboloid of revolution and a second cross section extending in the transverse direction with a radius of curvature smaller than that of the central paraboloid of revolution.

Description

FOR A VE};T The present invention relates to a vehicle marker lamp such as an auxiliary lamp for a vehicle in which the outer periphery of the reflecting surface of a reflector has an elongate shape when the reflecting surf ace is viewed from the front of the lamp.

Generally, an auxiliary la p for a vehicle is structured such that the light froa a light source is diffused not only in the upward and downward directions but also in the right and left directions by a reflector and/or a lens to thereby radiate the thus diffused light in front of the lamp.

Conventionally, as an example of such a lamp, there is known a structure in which the reflecting surf ace of the reflector is formed of a paraboloid of revolution and, in the lens, there are formed a plurality of fsch-eye len. elements.

However, in the above-mentioned conventional lamp, there are still found the following problems to be solved.

That is, the light reflected from the reflecting surface of the reflector provide. a substantially circular-shaped light distribution pattern P11 as shown by a solid line in Fig 6.

Therefore, even if this light distribution pattern P1' is diffused in the upward and downward directions as well as in the right and left directions by the fish-eye lens elanents of the lens, as shown by a one-dot chained line in Fig. 6, there is obtained a substantially ctrcular-shaped light distribution pattern P4' which is simply an enlarged version of the light distribution pattern P1'.

This raises a problem that the four corner portions D of the marker lamp respectively shown by hitching in Fig. 6 are not lit and are thus dark. Especially, in a backup Lair, there arises a problem that, since it cannot light the surface of a road in the rear of a vehicle widely, even if there exists an obstacle, it is difficult to see the obstacle.

Also, conventionally, there is also known a vehicle marker lamp such as an auxiliary lamp for a vehicle structured buch that a plurality of diffusingly reflecting surface element are applied to a paraboloid of revolution to thereby form the reflecting surface of a reflector, and there are applied a plurality of diffusing lens elosentss respectively extending in a direction intersecting at right angle to the aboua-mentioned plurality of diffusingly reflecting surface elementatothereby form a lens. However, even in the thus structured lamp as well, the lamp radiation pattern thereof provides a substantially circular-shaped light distribution pattern. Therefore, even this lamp is not able to solve the problem that the corner portions thereof are not lit and thus are dark.

Further, of course, # the above-mentioned problem also arise. in a lamp structured such that the outer periphery of the reflector is eet in a circular shape when the lamp is viewed from the front thereof. And, even in lamps structured such that the outer peripheries of the reflecting surfaces of their respective reflectors are set in a rectangular shape, or other elongate shape such as an oval shape, an elliptical shape or the like, because the lamp radiation patterns thereof respectively provide a substantially circular-shaped light distribution pattern, it ie impossible to solve the problem that the four corner portions of the respective lamps are not lit and thus are dark.

The present invention aims at eliminating the drawbacks found in the above-mentioned conventional lamps. Accordingly, it is an object of the invention to provide a vehicle maker lamp of a type that the outer periphery of the reflecting surface of a reflector han an elongate shape when the reflecting surface ie viewed from the front of the lamp, which is able to radiate well in front of the lamp including the four corner portions thereof.

According to the present invention, a vehicle marker lamp comprigec a ref lector having a reflecting surface for reflecting the light from a lignt source forwardly of the laap and a lens disposed in front of the reflector; the outer periphery of the reflecting surface of the ref lector being formed in an elongate shape when it is viewed troX the front of the lamp, wherein the central area of the reflecting surface situated around the light source is composed of a first surface having a reference surface forned of a paraboloid of revolution having a focal point in the neighbourhood of the light source, while at least one, and preferably both, peripheral area(s) of the reflecting surf ace adjoining the central area is respectively composed of a second surface, which is formed as a continuing eurface continuing directly uith the first surface, the or each of the second surfaces having a reference surface which has a first cross section extending in the longitudinal direction of the reflecting surface and a second cross section extending in the transverse direction, and the first cross section having a radius of curvature larger than that of the paraboloid of revolution while the second cross section has a radius of curvature smaller than that of the paraboloid of revolution.

The above- > entoned term "elongate shape" means, in this specification, a shape in which the lengths of the two directions thereof intersecting at right angles to each other are different from each other. For example, a rectangular shape, an elliptical shape, a diamond shape and the like fall within the scope of the term "elongate shape" Also, the above-mentioned term "central area means the area of the reflecting surface that is situated around the above-mentioned light source; that is, it is not always necessary that the central area should be literally situated in the centre of the reflecting surface.

Further, the above-mentioned "first surface" and "second surface" are not limited to any special shapes but various shape can be used as the "first and second surfaces", provided that they have the above-mentioned "paraboloid of revolution" and "curved surface" ae their respective reference surfaces. In this case, the "first surface" and Second surf ace" may be composed of the above-mentioned "paraboloid of revolution or "curved surface" itself.

Moreover, the above-mentioned term "continuing surface" means a surface which is connected to ite associated surface with no step between them: that ie, the "continuing eurface" includes not only a smoothly connected surface but also a surface which is connected in such a manner that a curved line is formed therein.

Thanks to this new structure, the reflected light from the reference surface of the first surface provide a substantially circular-shaped light distribution pattern which is similar to that of the conventional lamp, whereas the reflected light froi the reference surface of the second surface provides a light distribution pattern which spreads out beyond the corner portions of the outer periphery of the c1tcular-haped light distribution pattern.

Therefore, if the two kinds of light distribution patterns are diffused properly musing the reflector and/or lens as the need arises, then the front area of the lamp can be lit well up to the corner portions thereof.

When the above-mentioned peripheral areas are formed on the two aides of the above-mentioned central area, the light distribution pattern of the peripheral areas provides a substantially H-ohaped light distribution pattern with the central area as the center thereof; and, on the other hand, when the above-mentioned peripheral area is formed only on one side of the central area, the light distribution pattern of the peripheral area provide. a substantially T-.haped light distribution pattern which spreads out from the central area.

In the former structure, the front area of the marker lamp can be lit well up to the four corner portions thereof. On the other hand, in the latter structure, the front area of the marker lamp can be lit well up to two of the four corner portions thereof.

Employment of either of the two structures may be decided in accordance with the light distribution performance required in the marker lamp and/or restricting conditions in the structure of the marker ltsp (such as lamp size, lamp shape, lamp layout and the like).

If the above-mentioned elongate shape is a substantially elliptic Shape and the peripheral areas are formed on the two side of the central area, then the depth of a wall surface formed in the outer peripheral edge of the reflecting surf ace of the reflector can be set uniform or can be made to change gradually, which not only can enhance the appearance of the lamp but also can radiate well up to the four corner portions of the front area of the lamp.

The longitudinal direction of the reflecting surface may be oriented in any one of vertical, right and left, and diagonal direction. but if it is set in such a manner as to extend substantially in the vertical direction, then the abovementioned substantially T-shaped or substantially B-shaped light distribution pattern can be obtained as a pattern which can radiate substantially evenly in the right and left directions, thereby being able to light the surface of a road in front of the lamp more evenly.

Also if the above-mentioned reflecting surface is formed of room of diffuse reflector elements respectively extending in the longitudinal direction of the reflecting surface and also the lens is formed with rows of diffuse lens elements respectively extending in a direction transtrsely to the longitudinal direction, then not only the appearance of the lamp can be enhanced but also a desired lamp light distribution pattern can be obtained easily.

Further, if the above-mentioned vehicle marker lamp according to the present invention is used a. a backup lamp while the peripheral areas is modified eo as to be formed at a position under the central area, there is an advantageous that the surface of a road in front of the backup lamp can be lit widely, to thereby enhance the safety when the vehicle move back.

In the accompanying drawings Fig. I is a front view of an auxiliary lamp for a vehicle according to an embodiment of the invention Figs. 2 to 4 are sections taken along the lines II-II, III-II and IV-IV respectively in Fig, 1; Fig. 5 show light distribution patterns respectively to be formed by the reflected light from the reflecting surface of a reflector employed in the lamp, when it is assumed that a plurality of diffuse ref lector elements are not formed in the reflecting surface of the reflector and also when the lens of the lamp is removed; and, Fig. 6, similarly to Fig. 5, shows light distribution patterns respectively obtained by a conventional lap An shown in Pigs. 1 to 4, a vehicle marker lamp 10, such as an auxiliary lamp for a vehicle, according to the present embodiment is a backup lamp in which a lamp chamber is formed by a lamp body 12 and a lens 14 disposed in front of the lamp body (the term "front means the front of the lamp but, when it is viewed from the vehicle, it means the rear of the vehicle).

Within the lamp chamer, there is disposed a reflector 16 having an optical axis Ax extending in the longitudinal direction of the marker lamp, and there is also disposed a light source bulb 18 in such a manner that a filament 18a forming a light source thereof is positioned on the above-mentioned optical axis Ax.

The ref lector 16 includes a reflecting surface 16a which is used to reflect the light frown the light source bulb 18 in the forward direction, while the reflecting surface 16a is structured such that, when it is viewed from the front of the lamp, the outer periphery thereof is formed in an elliptic shape with a major axis thereof extending in the vertical direction.

The central area 16a1 (in Fig. 1, a circular area enclosed by a two-dot chained line) of the reflecting surface 16a is composed of a first surface 61 whose reference surface Slo consists of a paraboloid of revolution (the extension line of which is shown by a two-dot chained line in Fig. 2) having its focal point at the center of the filament 19a; and, the two peripheral areas 16a2 of the reflecting surface 16a, which are respectively situated on the two sides of the central area 16al in the vertical direction (that is, in the longitudinal direction of the reflecting surface 16a), are respectively composed of second surfaceS 82, that is, continuing surfaces which continue directly with the first surface Si. There second surfaces 82 are structured such that each of their reference surfaces 82e consists of a curved surface which has a vertical section (that is, a cross section extending in the vertical direction of the reflecting surface lfa) having a larger radius of curvature than that of the paraboloid of revolution and a hori2ontal section (that is, a cross section extending in a direction intersecting at right angle. to the longitudinal direction of the reflecting surface lSa) having a smaller radius of curvature than that of the paraboloid of revolution. And, in the reflecting surface 16a, there are disposed a plurality of diffuse reflector elements 165 each having a projecting cross section in such a manner that they extend in the vertical direction over the whole area of the reflecting surface 16a, so that the reflecting surface 16a is formed in a vertically striped manner.

The lens 14 includes a first lens portion 14A situated in front of the reflector 16 and a second lene portion 14B situated at the periphery of the fixst lens portion 14A, while the first and second lens portions 14A and 14B are connected together.

Zn the inner surface of the first lens portion 14A, there are formed a plurality of diffuse lens elements 14s which respectively extend in the horizontal direction and also the crose sections of which project. Alan, in the inner surface of the second lens portion 14B, there are formed a plurality of decorative lens elements which respectively extend in the horizontal direction.

Now, Pig. S shows light distribution patterns which are formed by the reflected light from the reflecting surface 16a when it is assumed that the above-mentioned plurality of diffuse reflector elements 165 are not formed. In Pig. 5, a light distribution pattern P1 is a light distribution pattern which is formed by the reflected light from the reference surface Slo of the first surface S1, whereas a light distribution pattern P2 is a light distribution pattern which is formed by the reflected light from the reference surface S2o of the second surface S2.

Since the reference surface Elo is composed of a paraboloid of revolution, the reflected light from the reference surface Slo, as shown in Pigs. 2 and 3, provides a light which is substantially parallel to the optical axis Ax. Therefore, the light distribution pattern Pi provides a substantially circular-shaped light distribution pattern. on the other hand, the reference surface 520 is structured such that the vertical section thereof has a larger radius of curvature than that of the reference surface Slo and the horizontal section thereof has a smaller radius of curvature than that of the reference surface 810. For this reason, the reflected light from the reference surface S2o, as shown in Figs.

2 and 4, provides a light which not only spread in the vertical direction with respect to the optical axis Ax but also intersects the optical axis Ax in the right and left direction.

As a result, the light distribution pattern P2 provides a substantially H-shaped light distribution pattern; in particular, if the light distribution pattern P1 ie diffused in the vertical direction, then there can be obtained a light distribution pattern P3 and, if the light distribution pattern P3 is further diffused in the right and left direction, then the light distribution pattern P2 can be obtained.

In fact, as described above, because the plurality of diffuse reflector elemente lEa are formed in the reflecting surface 16a and the plurality of diffuse lens elements 145 are formed in the inner surface of the first lens portion 14A of the lens 14, as the whole of the marker lamp, there is obtained a substantially rectangular-shaped light distribution pattern P4 which is shown by a one-dot chained line in Fig. 5.

Therefore, according to the present embodiment, in a lamp for a vehicle structured such that the outer periphery of the reflecting surface is formed in an elongate shape when it is viewed from the front of the lamp, the front area of the lamp including the four corner portions thereof can be lit well.

Also, in the present cmbodiment, since the above-mentioned elongate ehape is set as an elliptical shape, the depth of the wall surface to be formed on the outer peripheral edge or the reflecting surface lSa of the reflector 16 can be changed gradually, which makes it possible to enhance the appearance of the lamp, Further, because the major axis of the above-mentioned elliptical shape is set in such as a manner that a major axis thereof extends in the vertical direction, the above-mentioned substantially n-enaped light distribution pattern can be obtained as a pattern capable of substantially even radiation in the right and left direction, thereby being able to radiate the surface of a road in front of the lamp evenly.

Especially, since the lamp for a vehicle according to the present embodiment is a backup lamp, the lamp is able to radiate the surface of a road in front of the lamp widely, which makes it possible to enhance the safety when the vehicle reverses.

Also, in the present embodiment, because the reflecting surface lCa is composed of the plurality of diffuse reflector elements 16s extending in the vertical direction and also the lens 14 is composed of the plurality of diffuse lens elements 14a extending in the horizontal direction, not only the appearance of the marker lamp can be enhanced but also a desired lamp light distribution pattern can be obtained easily.

Claims (7)

1. An auxiliary lamp for a vehicle, the lamp comprising a reflector having a reflecting surface for reflecting the light from a light source forwardly of the lamp and a lens disposed in front of the reflector; the outer periphery of the reflecting surface of the reflector being formed in an elongate shape when it is viewed from the front of the lamp, wherein the central area of the reflecting surface situated around the light source is compaeed of a first surface having a reference surface formed of a paraboloid of revolution having a focal point in the neighbourhood of the light soured, while at least one peripheral area of the reflecting surface adjoining the central area is respectively colnposed of a second surface, which is formed as a continuing surface continuing directly with the first surface, the or each of the second surf aces having a reference surface which has a first cross section extending in the longitudinal direction of the reflecting surface and a second cross section extending in the transverse direction, and the first cross section having a radius of curvature larger than that of the paraboloid of revolution while the second cross section has a radius of curvature smaller than that of the paraboloid of revolution.

2. A lamp according to claim 1, wherein there are two of the peripheral areas, one on each side of the central area.

3. A lamp as set forth in claim 2, wherein the elongate shape is a substantially elliptical shape.

4. A lamp as set forth in any one of the preceding claims, wherein the longitudinal direction of the reflecting surface is substantially vertical.

5. A lama according to any one of the preceding claims, wherein the reflecting surface is composed of rows of diffuse reflector elements extending in the longitudinal direction of the reflecting surface and the lens is composed of rows of diffuse lens elements extending transversely to the longitudinal direction.

6. A lamp according to any one of the preceding clai:ne, which is a backup lamp.

7. A vehicle lamp, substantially as described with reference to Figs. 1 to 5 of the accompanying drawings.