DE20019147U1 - Traffic light system, in particular traffic lights - Google Patents

Description

Traffic lights, especially traffic lights

The invention relates to a traffic light system, in particular a traffic light, with a housing and at least one signal unit arranged in the housing, consisting at least of a light source, a reflector and a translucent pane closing the signal unit from a front side of the housing.

Traffic lights are known as traffic lights for regulating traffic at intersections, junctions, crossings and narrow passages. These well-known traffic lights usually have at least two signal units arranged one below or next to each other, which signal the respective switching status by means of colored radiation. The signal units usually consist of a light source arranged in the traffic light housing, a reflector and a disc that covers the signal unit, usually a diffuser. The colored signal can be achieved by using a colored light source or by using a correspondingly colored disc. These well-known traffic lights have certainly proven themselves in practice.

Since the control function that these systems are supposed to perform depends on the clear recognition of the signal displayed, extreme lighting conditions can result in the signal being displayed being difficult or even impossible to recognize. This situation often occurs at traffic lights when the sun is low and the sunlight hits the disc of the signal unit directly. The brightness of the sunlight can then exceed the brightness of the reflected light.

Telephone (0211) 572*13*:*' .'"l ! ' : BHB- _# B*}k, DOfs'eljtbrf *.$LZ*3.0020500) 40113276 Fax (0211)588*2*15 Stadt-Sparka'sVe, Düsseldorf (BLZ 30050110) 10090769

emitted signal, so that a road user does not perceive the switching status of the traffic light or even perceives it incorrectly, which can lead to extremely dangerous traffic situations and accidents.

Various designs are known in practice which attempt to improve the contrast between the displayed light signal and the ambient brightness even in extreme lighting conditions. For example, DE 197 37 028 A1 proposes to additionally equip the signal units with a strobe lamp with high light intensity and a switching frequency of 2 to 6 Hz. However, all of these known designs have the disadvantage that they only attempt to increase the emitted light intensity. In extreme lighting conditions, however, these measures are ultimately ineffective or the light signals to be recognized are not sufficiently clear.

Proceeding from this, the invention is based on the task of improving a traffic light system of the type mentioned at the beginning in such a way that even under extreme lighting conditions, such as sunlight directed directly at the signal unit, a clear recognition of the switching state of the signal system is ensured.

The solution to this problem is characterized according to the invention in that at least one reflective surface that can be switched on and off is arranged on the front side of the housing, surrounding the translucent pane of at least one signal unit.

With the inventive arrangement of the reflective surface around the disc of at least one signal unit, a construction is provided for the first time which enables clear recognition of the displayed signal even in extreme lighting conditions, since the reflective surface uses the directly incident bright sunlight to enhance the signal effect by reflecting it.

According to a practical embodiment of the invention, it is proposed that the switching on and off of the reflecting surfaces is coupled to the switching on and off of the light source of the respective corresponding signal unit.

This ensures that the reflection of one of the reflective surfaces can only be used to enhance the signal effect if the light source of the corresponding signal unit is also activated.

When using coloured light signals from traffic lights, it is further proposed that the reflective surfaces have a highly reflective colouring, with the reflective colouring corresponding to the colour of the respective associated signal unit.

According to the invention, the reflective surfaces can also be switched on and off by providing each reflective surface with an electrically switchable film or with an electrochromic disk which is either transparent or opaque depending on the switching state, so that the reflective effect of the surface only acts as a signal amplifier when the switching state is transparent.

For the design of the reflective surfaces, according to a preferred practical embodiment of the invention it is proposed that the reflective surfaces consist of switchable reflective liquid crystals such as those used for text displays.

Finally, the invention proposes that, according to an alternative embodiment to be used preferably, the reflecting surfaces consist of electromechanically actuated reflecting surface elements, such as are also known for the representation of text displays.

Further features and advantages of the invention are apparent from the accompanying drawing, in which an embodiment of a traffic light system according to the invention is shown schematically only as an example. In the drawing:

Fig. 1 is a front view of a traffic light system according to the invention;

Fig. 2 is a schematic longitudinal section along the section line H-II according to Fig. 1 and

Fig. 3 is an enlarged detailed view of section III according to Fig. 2.

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The traffic light system shown in the figures is a traffic light 1 with three signal units 2 arranged one below the other, which, viewed from top to bottom, usually display signals in the colours red, yellow and green.

As can be seen in particular from Fig. 2, the traffic light 1 has a housing 3 into which each signal unit 2 is inserted. Each signal unit 2 consists of a reflector 4 tapering in a funnel shape towards the interior of the housing 3, a light source 5 arranged at the lowest point of the reflector 4 and a disk 6 which closes the signal unit 2 flush with a front side 3a of the housing.

In the traffic light 1 shown, ring-shaped reflective surfaces 7 are arranged on the front 3a of the housing 3, surrounding the upper and lower signal units 2. As shown in the figure Fig. 3, these reflective surfaces 7 serve to reflect light rays 8 that directly impinge on the front 3a of the traffic light 1, such as sunlight from the low sun. The directly impinging light, which can outshine the brightness of the light sources 5 of the signal units 2, is thus used to be reflected via the surfaces 7.

In order to be able to clearly display the switching state of the traffic light 1 even in extreme lighting conditions, the reflective surfaces 7 are designed so that they can be switched on and off. In the embodiment shown, each reflective surface 7 is provided with an electrically switchable film 9, which is either transparent or opaque depending on the switching state. The switching state of the film 9 and thus of the respective reflective surface 7 is advantageously coupled to the switching state of the light source 5 of the respective signal unit 2 to which the reflective surface 7 is assigned.

As soon as a light source 5 is activated to display a light signal, the foil 9 is simultaneously switched to "transparent" so that directly incident light rays 8 can be reflected by the corresponding reflecting surface 7 so that even then the switching state of the traffic light 1 can be clearly identified.

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can be seen when the directly incident light outshines the brightness of the controlled light source 5.

In the embodiment shown, only the "red" and "green" signal units 2 are provided with the reflective surfaces 7, since these signals are the most important colors for traffic control. Of course, it is also possible to provide each or just one signal unit 2 with a corresponding reflective surface 7. If the signal units 2 emit colored light signals, it is advantageous if the reflective surfaces 7 are designed in such a way that they are colored and reflective according to the respective signal unit.

The traffic light systems designed in this way use the otherwise dazzling direct light to clearly indicate the switching status of the system via the reflective surfaces 7. Another particularly advantageous feature is that existing traffic light systems can also be retrofitted with the reflective surfaces in a simple and cost-effective manner.

Reference list

1 traffic light

2 Signal unit

3 Housing 3a Front

4 Reflector

5 Light source

6 slice

7 reflective surface

8 Light beam

9 Slide

Claims (6)

1. Traffic light system, in particular a traffic light, with a housing ( 3 ) and at least one signal unit ( 2 ) arranged in the housing ( 3 ), at least consisting of a light source ( 5 ), a reflector ( 4 ) and a translucent pane ( 6 ) closing the signal unit ( 2 ) from a housing front side ( 3a ), characterized in that at least one reflective surface ( 7 ) which can be switched on and off is arranged surrounding the translucent pane ( 6 ) of at least one signal unit ( 2 ) on the front side ( 3a ) of the housing ( 3 ). 2. Traffic light system according to claim 1, characterized in that the switching on and off of the reflecting surfaces ( 7 ) is coupled to the switching on and off of the light source ( 5 ) of the respective corresponding signal unit ( 2 ). 3. Traffic light system according to claim 1 or 2, characterized in that the reflecting surfaces ( 7 ) have a highly reflective coloring, the reflective coloring corresponding to the color of the respective associated signal unit ( 2 ). 4. Traffic light system according to at least one of claims 1 to 3, characterized in that each reflecting surface ( 7 ) is provided with an electrically switchable film ( 9 ) which is either transparent or opaque depending on the switching state. 5. Traffic light system according to at least one of claims 1 to 4, characterized in that the reflecting surfaces ( 7 ) consist of switchable reflecting liquid crystals. 6. Traffic light system according to at least one of claims 1 to 4, characterized in that the reflecting surfaces ( 7 ) consist of electromechanically actuated reflecting surface elements.