The proposed invention belongs to the field of transporting, more precisely to lightning equipment for motor vehicles, namely to fog lights, where a sequence of LEDs, namely light emitting diodes, is used as a light source.

The purpose of the invention is to create a fog light, where the required optical characteristics of the fog light in the view of achieving a bright/dark border and preventing of reflecting glare could be achieved despite to application of cheap classic single LEDs (i.e. "single chip LEDs" or "chip size LEDs" or "single chip based LEDs") instead of special "multi chip LEDs".

Legal regulations concerning fog lights (like e.g. STM) require achieving of the so- called bright/dark border. The first reason for that is preventing of reflection glare due to uncontrolled directing of light beams in undesired directions above the horizontal plane extending through the optical axis of the fog light, since said glare may impact other traffic participants, in particular drivers of vehicles approaching from opposite direction. The second reason for that refers to adjusting of the light beam on the vertical direction. Consequently, the present regulations define a bright/dark border, which should extend at 1 below the optical axis of the light, by which also sharpness i.e. a contrast of said bright/dark border in the sense of gradient of illumination.

According to the prior art, said bright/dark border can be achieved either by using a screen or by means of a surface-directing reflector combined with a special light source in the form of a very precisely manufactured "multi-chip" LED.

Whenever the bright/dark border is achieved by means of a screen, the last is mounted in the focus of a condensing lens of the fog light in order to determine the border between the light permeable and light screening area. Consequently, the gradient of illumination in the area of said bright/dark border is acceptable, but the position of said border is difficultly achieved, since it crucially depends on accuracy of mounting said screen. In practice, only a part of light rays blocked by screen are then redirected into appropriate direction, and the rest is dissipated, which leads to reduction of illuminating capability and efficiency of the light as such. Besides, such screen represents an additional part of the light, which is relatively complicated from quite manufacturing aspects, which usually essentially increases the production costs. The major problem is however said precise assembling, since even minor deviations of the position of such screen result in essential deviations of the bright/dark border.

On the other hand, a combination of a surface- directing reflector and a light source in the form of a "multi-chip" LED can also be used. Those skilled in the art are aware that such multi-sliced or "multi-chip" LEDs are commercially available, but are technologically an extremely sophisticated product, in which several flat rectangular LEDs are minimally separated apart from each other and linearly aligned in a sequence, by which a quality light source is obtained with an acceptable contrast between the illuminated and dark area, but the price of such product, at least when compared with conventional "single chip" LEDs is extremely high and beyond the reality in the field of fog lights. However, a successful solution of the previously mentioned technical problem could despite to these circumstances enable economically acceptable exploitation of LEDs even in the field of fog lights.

The proposed invention refers to a motor vehicle fog light comprising a light source on the basis of LED, wherein such fog light comprises a casing with a light permeable front wall, a surface-directing reflector, which is embedded within said casing and comprises at least a rear surface, which is optionally a reflecting surface, as well as two opposite active reflecting surfaces, which are located apart from each other and above each other and coincide towards said rear surface, and moreover also two opposite supplemental reflecting surfaces which are among others adapted to determine a width of the light beam and are also arranged apart from each other between said active reflecting surfaces and also coincide towards said rear surface. Besides, said fog light also comprises a light source, which is arranged within the interior of the reflector and is adapted to cooperate with the previously mentioned reflecting surfaces, so that light beams, which are generated by the light source, are directed to each desired direction, wherein said light source consists of a sequence of flat rectangular LEDs, which are arranged apart from each other in at least approximately linear alignment.

The invention proposes that said reflector comprises

- a linear rear wall with a straight central line;

- a linear focus, which is arranged at a pre-determined focal distance apart from said central line of the rear surface and extends parallel to said central line;

- at least approximately parabolic active reflecting surfaces; and

- flat supplemental reflecting surface;

as well as that the light source is available in the form of a sequence of rectangular flat LEDs, which are each per se conventional "single chip" i.e. "chip size" LEDs, which are along the complete length of said sequence arranged equidistantly apart from each other in a linear alignment along the focal line (extending parallel to the central line of the rear surface of the reflector;

an moreover also that the sequence of linearly aligned LEDs extends within a predetermined area, which is defined on the basis of maximal deviations of the position of each disposable LED apart from the linear focus below and/or above said linear focus.

In the preferred embodiment of the invention, the supplemental reflecting surfaces are are arranged either at least approximately rectangular or inclined with respect to the rear surface of the reflector. In the reflector, the height of which in a direction of the optical axis is between 25 and 40 mm, the focal distance between the focus and the central line VS on the rear surface of the reflector is 5 to 16 mm. The light source consists of a sequence of a defined length and of equidistantly apart from each other arranged "single chip" i.e. "chip size" LEDs, wherein said sequence has a length and wherein each LED in said sequence is located within the pre-determined area, which is defined by means of allowable deviation of the position of each LED, which is less than 0,2 mm below the linear focus and less than 0,4 mm above the linear focus.

The invention will be described in more detail on the basis of an embodiment, which is shown in the attached drawing, where

Fig. 1 is a schematically presented front view of a motor vehicle fog light comprising a light source on the basis of LED;

Fig. 2 is a separate perspective view of a reflector of said fog light according to the invention;

Fig. 3 is a cross-section along the plane A - A according to Fig. 2; and

Fig. 4 is a cross-section along the plane B - B according to Fig. 2.

A motor vehicle fog light with a light source 3 on the basis of LED (Fig. 1) comprises a casing 1 with a light permeable front wall 1 1, a so-called surface-directing reflector 2 as well as a light source 3. Said surface-directing reflector 2 is embedded within the casing 1 and comprises at least a rear surface L, which is optionally a reflecting surface, as well as two opposite active reflecting surfaces Kl, H2, which are located apart from each other and above each other and coincide towards said rear surface L, as well as two opposite supplemental reflecting surfaces B', B", which are among others adapted to determine a width of the light beam and are also arranged apart from each other between said active reflecting surfaces Kl, K2 and coincide towards said rear surface L.

Said light source 3 is arranged within the interior of the reflector 2 and is adapted to cooperate with the previously mentioned reflecting surfaces Kl, K2, B', B", L, so that light beams, which are generated by the light source 3, are directed to each desired direction. Said light source 3 consists of a sequence of flat rectangular LEDs 3', which are arranged apart from each other in at least approximately linear alignment.

Moreover, the fog light according to the invention is characterized by the reflector 3 (Fig. 2), which comprises

- a linear rear wall L with a straight central line VS;

- a linear focus LF, which is arranged at a pre-determined focal distance F apart from said central line VS of the rear surface L and extends parallel to said central line VS;

- at least approximately parabolic active reflecting surfaces Kl, K2; and

- flat supplemental reflecting surfaces B', B".

Said supplemental reflecting surfaces B', B" are arranged either at least approximately rectangular or inclined with respect to the rear surface L of the reflector 2.

Moreover, the light source 3 is characteristic for the fog light according to the invention and is available in the form of a sequence of rectangular flat LEDs 3', which are along the complete length Y of said sequence arranged in a linear alignment and are equidistantly separated apart from each other, wherein each of these LEDs 3 ' per se is available as a conventional "single chip" LED and is therefore in view of technologic aspects much more simple, much easier to purchase and also much cheaper than the very special "multi chip" LEDs, which are generally known in the art and commercially available under the trademark OSTA ^® of the manufacturer OSRAM. Said LEDs 3 ' of each sequence are each per se arranged along the focal line LF extending parallel to the central line VS of the rear surface L of the reflector 2.

Moreover, the fog light according to the invention is characterized in that the sequence of linearly aligned LEDs 3 ' extends within a pre-determined area, which is defined on the basis of maximal deviations of the position of each disposable LED 3 ' apart from the linear focus LF below and/or above said linear focus LF (Figs. 3 and 4).

In the fog light, where for example the height of the reflector 2 in a direction of the optical axis is between 25 and 40 mm, the focal distance F between the focus LF and the central line VS on the rear surface L of the reflector 2 can be 5 to 16 mm. The light source 3 consists of a sequence of "single chip" i.e. "chip size" LEDs 3', which are arranged equidistantly apart from each other, said sequence having the length Y and each LED 3' in the sequence is located within the pre-determined area, which is defined by means of still allowable deviation of the position of each LED 3' less than 0,2 mm below the linear focus LF and less than 0,4 mm above the linear focus LF.

Consequently, when previously mentioned features of the reflector 2 and the light source 3 are considered, despite to substitution of special "multi chip" LEDs with a sequence of essentially cheaper and acceptable "single chip" LEDs, the required optical characteristics of the fog light can also be achieved, wherein the light beams are directed in each desired direction in order to prevent reflecting glare and to assure a correct position and contrast of a bright/dark border.