HUP0202566A2 - Light source for signalling devices, light signalling device and light signalling system - Google Patents

Abstract

In the display element with light sources, which in particular contains LEDs (3) as light sources, the light sources are placed on a base plate (2) at a specified distance from an optical element (4), where the maximum extent of the surface occupied by the light sources is significantly smaller than the distance between the light sources and the optical element (4) is elected. The light signaling device (1) also contains at least one such display element and at least one optical element (4). In light signaling systems (5) consisting of light signaling devices (1), if more than one light signaling device (1) is used, the individual devices are arranged at distances corresponding to equal light path lengths extending to the optical elements (4) assigned to them, which lie in a common plane. By using advantageous electrical switching arrangements, particularly high operational reliability of light signaling systems (5) can be achieved. HE

Description

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PUBLICATION

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Light source display element, light signaling device and light signaling system

The invention relates to a display element with a light source, in particular light emitting diodes as a light source, which comprises two or more electric light sources arranged in a common plane on a base plate, to a light signaling device comprising such a display element with a light source, and to light signaling systems comprising such light signaling devices.

Light signaling systems are widely used in many areas, which communicate information, give warnings or perform other similar functions by means of some suitable light signal. Traffic lights are a well-known typical application of light signaling systems. In some areas of application of such light signaling systems, such as the traffic control mentioned as an example, issues related to service life and operational safety arise as very important aspects. Therefore, there are strict regulations in force regarding the operation and operating parameters of light signaling systems, such as minimum brightness, operational safety and the clarity of the display to be displayed, which must be taken into account when designing the devices and systems.

Various light-emitting devices can be used as light sources. In light signaling systems, light-emitting diodes, commonly abbreviated as LEDs, can be used as light sources, for example. The advantage of these devices is that they have a very long lifespan compared to incandescent lamps and are also significantly smaller in height. Thanks to the latter advantageous property, the structural size of the light signaling system is not significantly affected by the size of the chosen light source.

-2Below are presented known light signaling devices containing LEDs as light sources based on Figures 6 and 7 of the attached drawing.

Figure 6 shows a light signaling device in which a plurality of LEDs 20 are arranged on a base plate 21 in a uniform distribution extending over approximately the entire illuminating surface of the device. In front of each LED 20, a lens serving as a secondary optical element 23, for example a collecting lens, is arranged. The device also has a primary optical element 22 serving as the illuminating surface of the device, which may be, for example, a headlamp, a front cover or a lens unit.

The secondary optical element converts as much of the light emitted by the light source as possible into useful light. The primary optical element serves to distribute the light emitted by the light source and modified by the secondary optical element in a suitable manner in order to achieve the values required by, for example, DIN 67527 or EN 12368 standards. For this purpose, transparent or tinted reflector discs or lenses can be used.

Light signaling systems can be designed by known measures so that their detection is not disturbed by phantom light from other external light sources, in particular sunlight. For this purpose, it is known to incorporate various lamella or honeycomb inserts, which are usually placed between the primary and secondary optical elements.

Figure 7 shows a further known light signaling device, which comprises a light source unit 24 consisting of a few high-intensity LEDs 20 arranged on a base plate smaller than the illuminating surface. In front of the light source unit 24 consisting of 20 LEDs, a secondary optical element 25 designed as a single lens is arranged, which can also be a collecting lens as an optical element suitable for achieving the desired effect, or a Fresnel lens in order to achieve other advantages. The device also has a primary light output optical element 22.

Various conventional control devices are known for controlling light sources. In most cases, strict regulations apply to the operational reliability of the control or the clarity of the display. For example, for light signaling devices according to DIN VDE 0832, there is a requirement that

-3that they must comply with the failure behaviour of metal filament lamps. This means, for example, that if the brightness of the display device drops below a predetermined value due to the failure of one or more LEDs, or if the linearity of the luminous intensity is no longer ensured, the current of the LED signalling system must be switched to a high-resistance mode equivalent to a circuit break. This ensures that no current that can be detected by the control flows through the failed light signalling device, similar to a filament break.

An active monitoring circuit can be used to create an electrically high-resistance operating state, for example, which switches to a high ohmic resistance when a fault is detected. For this, the operation of the LED is monitored by a microcontroller unit that measures the current flowing through the LED or monitors the light emitted by the LEDs with optical sensors, or other known comparator electronics, which, when a fault is detected, triggers or operates a safety element, such as a semiconductor circuit or a relay, and switches it to high resistance. This requires the use of additional electronics in the light signaling system, which causes additional costs and is itself a source of error.

Another option is to passively switch off the light signaling system. For this, the LED circuit and the electronics connected upstream of it are designed in such a way that no current can flow through the display element if a certain number of LEDs fail. This can be achieved, for example, by connecting all the LEDs in series with a single power source. In this case, if any one LED fails, no current flows through the light signaling system.

On the other hand, in cases where the operational reliability of the signaling system needs to be increased and the failure of several LEDs can be tolerated, the LEDs can be connected in parallel in several branches. The control of such a parallel connection of LEDs can be done in two ways. One option is that each branch has its own control/power source. In the event of a failure of a branch, the brightness of the signaling system is reduced. The other option is that all branches of the parallel connection formed from LEDs have a common control, for example a constant

-It has a 4-amp current generator so that in the event of a branch failure, the other branches receive the current of the failed branch. Thus, thanks to the characteristic curve of the light-emitting diodes, the amount of light emitted is approximately constant. The uniformity of the light distribution and/or the luminous intensity naturally also depends on the optical system used.

In systems using the latter switching method, it must also be ensured that in the event of a certain number of LED failures (actively or passively), the entire system is switched off even if there are still intact LEDs. The switching off can be achieved either by means of a microcontroller unit mentioned above or by appropriately dimensioning the components used. For example, if the LEDs are divided into three branches, which operate from a common current generator, and the total current is set to 1.5 times the maximum permissible current of an LED, then initially approximately half of the maximum permissible current flows through each LED. In the event of a failure of one branch, the current flowing through will be 0.75 times the permissible current, while in the event of further LED failures, the current of the last LED will exceed its maximum permissible current. The consequence of this is that this (last) LED will theoretically be destroyed, which makes the light signaling system highly resistant. However, in practice, LEDs can operate with a current greater than the maximum allowable current for a certain period of time.

There are also known systems that operate with a diode matrix in which parallel circuits of LEDs are connected in series to increase operational reliability. The current is only interrupted if one of the parallel circuits fails completely or is switched off. In other parallel circuits, individual LEDs can fail without prematurely limiting the operational capability. However, this requires the installation of LEDs selected according to their forward voltage so that an initially uniform current distribution is created in the parallel circuit. It must also be taken into account that the luminous intensity of the emitted light will not be uniform due to differences in optical output powers.

If a light signaling system contains parallel connections of series-connected LEDs, then each series-connected LED must be sufficiently distributed over the

-5 on the lighting surface, so that in the event of a failure of a given LED row or LED chain, the current lighting display is not distorted to an unacceptable extent. However, when an individual LED chain fails, the light intensity changes to a noticeable extent even in such systems.

Various problems may arise when using the prior art light signaling devices described above with the aid of Figures 6 and 7.

The light signaling device of Figure 6 contains a large number of LEDs, each of which has its own separate secondary optical element. In such devices, if a single LED fails, the luminous intensity changes significantly.

In contrast, in the light signaling device shown in Figure 7, all light sources (LEDs) are placed behind a lens. Here, however, approximately parallel light guidance within the optical system is only possible to a limited extent. This results in a higher scattered loss of the light distribution and, especially when viewed from the side, the light density is not uniform. In addition, it is significantly more difficult to reduce the phantom effect. Furthermore, due to the placement of a large number of LEDs in a small space, local temperature increases can occur in the vicinity of the LEDs, which has a negative effect on the service life of the LEDs.

The aim of the invention is to create an improved light source display element, an improved light signaling device, and light signaling systems equipped with at least one such light signaling device, compared to those described above.

The aim is achieved by designing and using a light source display element which comprises two or more electric light sources arranged in a common plane on a base plate, and the light sources are arranged according to the invention in an arrangement occupying a surface having a maximum extent d on the base plate at a specified distance a from an optical element, where said maximum extent d of the surface occupied by the light sources is chosen to be smaller than the predetermined distance a.

To achieve the set goal, we have developed a light signaling device according to the invention, which has at least one light source with the above characteristics.

-6 also comprises a display element and at least one optical element, and in which the at least one optical element is arranged at a distance a from the associated at least one light source display element, which distance is greater than the largest extent d of the area occupied by the light source(s).

The above light signaling devices according to the invention can be used to form light signaling systems according to the invention, which include at least one such light signaling device, and in the case of using more than one light signaling device, these are arranged in the light signaling system at distances corresponding to equal light path lengths from the individual light sources to the optical elements assigned to them, which lie in a common plane.

By using the light source display element, light signaling device and light signaling system according to the invention, the redundancy of the light signals can be increased and thus greater reliability and service life can be achieved. The optical appearance of the light display does not change significantly in terms of optical and electrical characteristics until the end of its service life. The failure of a light source remains almost imperceptible to the observer, since neither the light intensity nor the light distribution nor the light density changes noticeably. This effect is all the better, the more precise the light source is and the smaller the divergence of the individual light sources. Therefore, a parallel circuit branch can be operated until the failure of the last light source in it, while previous systems had to be switched off earlier due to the risk of decreasing light density and confusion and unrecognizability of the displayed symbol. Light signaling systems according to the invention comprising series connections of parallel circuits of light sources also cease to function permanently only if all light sources of such a parallel circuit of light sources are faulty or interrupted.

Light-emitting diodes, i.e. LEDs, can be used as light sources very advantageously. These can be connected in series with a suitable electrical energy source, in particular a current generator, so that in the event of a failure of an LED, the other LEDs take over the energy supplied to the failed LED. Due to the typical characteristics of the current/luminance characteristic curve of LEDs, the failure of an individual LED is compensated for in the emitted light intensity.

-7 In the event of a malfunction, passive shutdown is also possible, thereby fulfilling the requirement for monitoring the light signaling systems with a control device. In the light signaling systems designed according to the invention, it is therefore not necessary to use shutdown electronics, which are an additional cost and source of error, and the omission of these or such has no detrimental effect on the safety of the shutdown.

If the power source is designed so that the current is regulated in direct proportion to the input voltage, the brightness of the light signal can be regulated by changing the voltage without compromising safety, provided that the monitoring implemented by the control device is set to the current corresponding to the minimum brightness as a limit value.

By using a secondary optical element, for example a collecting lens placed at a specified distance in front of the light source, a nearly parallel light stream can be created, whereby the desired distribution of the outgoing light can be achieved with good efficiency. Phantom light reducing elements, such as lamella or honeycomb inserts, can additionally be inserted into the light signaling device according to the invention.

By setting the distance of the secondary optical element from the light sources to ten times or more of the largest surface area occupied by the light sources, it is possible to make the LEDs, or small groups of them, appear almost like point light sources. This means that each LED or LED group creates an almost identical image on the display plane.

The light signaling devices according to the invention may advantageously also have a light-emitting primary optical element, which emits the light in a specific direction and in a desired distribution in order to improve the efficiency and/or limit the effect of sunlight phantom light.

If the required or desired number of light sources requires the use of several light indicating devices (light source and associated secondary optical element) according to the invention, it is advisable to distribute them evenly on the illuminated display surface in order to obtain a homogeneous luminance. The luminous display elements of each light indicating device

-8 are arranged in series-connected parallel connections so that the light signaling system containing multiple light signaling devices does not immediately and necessarily switch off in the event of a failure of individual LEDs.

Due to the modular structure of the light signaling system according to the invention, the included modules, for example the light source display elements (base plates with LEDs), can be easily replaced. This is advantageous, for example, because the light signaling systems according to the invention can be used for multiple purposes. The arrangement configuration and combination of the light source signaling elements included in a given light signaling system according to the invention can be easily changed and thus a different symbol can be displayed. In addition, defective, broken modules can be easily replaced, simplifying maintenance and reducing the costs involved.

The essence of the invention is described in more detail below by presenting exemplary embodiments with reference to the attached drawing. In the drawing,

Figure 1 shows a schematic diagram of an exemplary light signaling device according to the invention,

Figure 2 is a simplified line diagram showing a light signaling system consisting of several light signaling devices according to Figure 1, the

Figure 3 is a front view of the light signaling system according to Figure 2,

Figure 4 shows a preferred circuit diagram of the light signaling device according to Figure 1,

Figure 5 shows a preferred circuit diagram for the light signaling system according to Figure 2,

Figure 6 is a known light signaling system constituting the state of the art, while

Figure 7 shows a diagram of another known light signaling system, also belonging to the prior art.

Figure 1 of the attached drawing shows a line layout diagram of an exemplary light signaling device 1 according to the invention, comprising a display element according to the invention, which in the given embodiment comprises LEDs 3 as light sources arranged in a common plane on a base plate 2, and a secondary optical element 4.

-9 can be seen. In the example shown, three LEDs 3 are arranged in a concentrated, close arrangement, for example at the corners of an equilateral triangle, on the base plate 2. The number of LEDs 3 can be varied, and they can be arranged in other shapes, for example in concentric circles around a common center or even in a row. It is advisable to choose the arrangement shape of the LEDs 3 so that the area of the base surface occupied by the arrangement is as small as possible.

On the base plate 2, of course, other electrical circuit elements not shown in the drawing, such as resistors, as well as electrical conductors, generally designed as printed circuit elements, for connecting the LEDs 3 to the outside and to each other, are also arranged or formed.

Opposite the light-emitting surface of the LEDs 3, at a specific distance from them to be described in more detail later, an optical element 4 (for example a collecting lens) is arranged, which will be referred to hereinafter as a secondary optical element 4.

When powered by a suitable power source, the LEDs 3 emit light of a specific wavelength. The emitted light is converted into a nearly parallel light stream by the secondary optical element 4. Due to the arrangement and design of the LEDs 3, the light signaling device 1 according to the invention converts a very large part of the light emitted by the LEDs 3 into useful light. This is achieved, for example, by placing the LEDs at the focal point of the lens, i.e. the distance of the lens from the LEDs 3 is at least approximately equal to the focal length f of the lens, as a result of which the light rays continue as parallel beams after their refraction on the lens.

The LEDs 3 are arranged on the base plate 2 in such a way that the maximum area d of the surface they occupy is smaller than the distance of the LEDs 3 from the secondary optical element 4. In order for the LED group to be considered as an approximately point-like light source behind the common collecting lens, the inequality a » d must be fulfilled. This allows us to achieve that each of the LEDs 3 creates an approximately identical image on the display plane.

Ideally, the secondary 4 optical elements will produce a nearly parallel beam of light after passing through the lens. For practical reasons, this should be

- 10 strive to have the lowest possible divergence of the beam in the beam path region after passing through the secondary optical element 4. Regarding the divergence, the angle of about 10° shown in the drawing is considered an exemplary appropriate value. This allows us to ensure that the failure of one of the 3 LEDs does not have a significant effect on the light distribution after the secondary optical element 4. Assuming that a nearly parallel beam is created and a » d, the ratio of the maximum extent d to the distance a can be approximated by d/a = tan α, thus giving a value of less than 0.1 for d/a, which must be taken into account when designing the dimensional ratios of the light signaling devices 1 according to the invention.

The failure of one LED 3 is imperceptible to the observer if the light loss that has occurred can be compensated for by the light output of the other LEDs. This can be achieved, for example, by connecting the LEDs 3 in parallel as shown in Figure 4. In the connection arrangement shown in Figure 4, the light signaling device 1 contains several LEDs 3 connected in parallel. A current generator 10 is connected in series with the LEDs connected in parallel, which supplies a current I to power the LEDs 3. The current generator 10 can be designed so that the current I is proportional to the supply voltage connected to it. The brightness can then be modified by changing the voltage without reducing safety. The corresponding control device only needs to react if the primary current does not reach the current required for the minimum brightness.

In this type of connection, the failure of any 3 LEDs is compensated, at least to a good approximation, by the light output of the other LEDs (increased redundancy). In addition, with appropriate sizing, any switch-off condition can be defined. The optical appearance of the light signal does not change significantly in terms of optical and electrical characteristics until the end of the service life of the light signal (i.e. until the last LED breaks), since neither the light intensity, nor the light distribution, nor the light density change noticeably.

The number of LEDs connected in parallel is in practice a compromise between reliability and cost of the device. In order to be able to operate until the last LED fails, the reverse current of the circuit must not be significantly greater than the permissible current of one LED. The more LEDs are operated in parallel, the more LEDs will be required for the i

-11 to achieve the required luminous flux. On the other hand, if the number of LEDs operated in parallel is reduced, the redundancy of the group is reduced. In addition, the size of the LED group is also an additional consideration for determining the number of LEDs connected in parallel. If the size d is too large, the distance required from the secondary 4 optical elements increases too much. In addition, the spatial dimensions given in advance for the device must also be taken into account.

Therefore, if we need to place too many LEDs 3 on a base plate 2 , it is advisable to install several light signaling devices 1 next to each other within a given system in order to ensure the required uniform light intensity over the entire lighting surface.

Below, with reference to Figure 2, we present an exemplary light signaling system 5 in which several light signaling devices 1 according to Figure 1 are incorporated.

In the example shown in Figure 2, the light signaling system 5 according to the invention comprises closely arranged light signaling devices 1 according to the invention, each consisting of a base plate 2, LEDs 3 and a secondary optical element 4. The individual components of the light signaling system 5 are installed in a housing 6. The housing 6 may be, for example, a structural unit produced by injection molding from a suitable plastic material, which may be provided with support and fastening elements not shown in the drawing at appropriate locations, which serve to mount the structural elements. The light signaling system 5 may have a base plate 2 containing several LED groups together, but according to an alternative solution, the base plate 2 may also be of modular design. In the case of a modular design, the support and fastening elements are such that certain structural units can be easily replaced. This allows, for example, the display elements (the LEDs 3 and the base plate 2 carrying them) to be rearranged in a simple way so that different symbols can be displayed with them. In the meantime, attention must also be paid to the geometric shape of the individual base plates 2. It is advisable to strive for a gap-free arrangement of the base plates and for them to be able to be arranged next to each other. This can be achieved, for example, with a hexagonal base shape, which allows a honeycomb-like arrangement. In the case of a modular design, furthermore, one

- 12 damaged or defective display elements can also be easily replaced. A plug-in system can be used to attach the structural units to the housing 6, but other attachment methods (terminals, soldering, etc.) are also possible and feasible.

The light signaling device 5 also includes a primary optical element 7 arranged on the front side of the housing 6, which serves to adjust the light distribution according to predetermined parameters. Transparent or optionally tinted reflector discs or lens systems, or combinations thereof, can be used as such primary optical elements 7.

If desired, the light display system 5 may also include additional or supplementary optical element(s) 8, which may be, for example, lamellas or honeycomb inserts. The purpose of the additional optical element(s) 8 is to suppress the harmful effects of the environment on the light display system 5, such as the phantom light caused by sunlight. Such unwanted and disturbing external environmental effects can be at least partially handled, in particular further attenuated, by the appropriate design of the above-mentioned primary optical element 7 itself.

In a light signaling system 5 formed, the light signaling devices 1 can preferably be placed next to each other in such a way that the secondary optical elements 4 associated with them form a common plane. As shown in Figure 2, for example! in the light signaling system 5 according to the invention, the base plates 2, and consequently the LEDs 3, also lie in a common plane. According to a preferred embodiment, the secondary optical elements 4 and the base plates 2 are designed as a continuous, complete unit (i.e. a secondary optical element unit and a continuous base plate unit). However, other arrangements and embodiments can also be implemented, provided that the light arriving at the secondary optical element(s) 4 is essentially uniform and the light source is point-like, i.e. the above-defined a » d inequality is satisfied for the display element. The groups of LEDs 3 and the secondary optical elements 4 are placed in a purposefully evenly distributed arrangement in order to ensure that the light density is as homogeneous as possible on the illuminating surface of the light signaling system(s) 5 formed from them.

Figure 5 shows a preferred circuit diagram of the light signaling system 5 according to the invention, as shown in Figure 2. Each light signaling system 1

The LEDs of the -13 devices are connected in parallel with each other as mentioned above, while the parallel connections formed from the LEDs are connected in series with each other. This series circuit is supplied with a current I by a power supply 10. Such a switching arrangement creates a uniform power distribution over all the parallel circuits. Passive disconnection makes it possible to monitor the entire system. The signaling system only fails permanently when a parallel circuit completely ceases to function. Until then, however, the luminosity remains homogeneous.

An example of the design and application of the light signaling system according to the invention is described below with reference to Figure 3 of the attached drawing.

For example, to generate the required luminous flux of a traffic light system, approximately sixty LEDs, such as OSRAM PowerTOPLED® LEDs, are required. If such a light were to be designed as a single light signal device 1 according to Figure 1, the sixty-one LEDs required due to the dimensioning of the light output 2 would occupy an area of approximately 1500 mm, which corresponds to a maximum surface area of d > 43 mm. If, in view of the requirement for the pointiness of the light source, the inequality condition d/a < 0.1 were also to be observed, in the case of such a structural design, the distance a would be 430 mm, which is not feasible with conventional traffic lights. For this reason, we have created and developed the light signal system 5 according to Figure 2, by using which the aforementioned light output requirement can be met with practically feasible structural dimensions.

Figure 3 shows a front view of a light signaling system 5 according to Figure 2 designed as a traffic light outlined above. The usual nominal diameter of the entire lens plate of a traffic light (i.e. a visible field of the traffic light) is 210 mm or 300 mm. In other words, for the smaller light, the nominal diameter of the primary optical element 7 according to Figures 2 and 3 should be 210 mm. If the distance a is chosen to be approximately 50 mm, the extension d is approximately 5 mm. With these dimensions, nineteen lenses each with a diameter of approximately 50 mm can be arranged as secondary optical elements 4 under the primary optical element 7 with a diameter of 210 mm, each of which forms groups of three LEDs 3 behind each of which

-14 light sources can be placed. The lenses serving as secondary optical elements 4 can be arranged in the configuration shown in Figure 3 by placing a lens of secondary optical element 4 concentrically with the center of the circular primary optical element 7, and then surrounding this in a circular and closely touching arrangement with six or twelve identical secondary optical element lenses 4 in concentric circles with their centers coinciding with the center of the primary optical element 7. Under each secondary optical element 4, three light sources consisting of 3 LEDs are placed in an arrangement lying at the vertices of equilateral triangles. With such a geometric arrangement, the light signaling system 5 serving as a traffic light will contain a total of 57 LEDs, which is adequate and sufficient to create the required luminous flux.

As shown in Figure 3, the twelve lenses of the secondary optical elements 4 centered on the outer concentric circle are partially cut off by the circular outer circumference of the primary optical element 7. Although only circular lenses are shown as the secondary optical elements 4 in Figure 3, there is no obstacle to the lenses also filling the intermediate fields and extending into the corners so that the entire surface of the primary optical element 7 is at least approximately uniformly illuminated.

Due to the small extent d resulting from the small number of LEDs 3 arranged in groups of three as light sources behind the individual secondary optical elements 4 arranged in the above manner and shape on a common base plate, a relatively small value can be chosen for the distance a, whereby the light signaling system 5 becomes compact overall. The distribution of the groups of LEDs 3 over a relatively large surface area and their low local concentration enable favorable heat dissipation, thereby increasing the service life of the individual LEDs.

The scope of protection defined by the appended claims is not limited in the least to the embodiments shown above as examples. Within the scope of protection, it is also possible to design light signaling systems according to the invention that only contain a single light signaling device 1 according to the invention and with the aforementioned additional structures, such as the primary optical element 7, the additional optical element 8 designed as lamella or honeycomb inserts.

-15 and any additional components are placed in a housing 6. Several such individual systems can be assembled into a multiple system, which can be operated with either a common or separate individual power generators 10 as the power source(s).

In addition to the LEDs mentioned and described above, other light sources, such as incandescent or other lamps, can also be used as light sources. In addition to constant current generators, other electrical energy sources (such as a combination of a battery and a solar cell) can also be used as energy sources, provided that they are able to permanently supply the minimum required current. Although the above-described implementation examples describe passive control of the light sources, it is also possible to use active controls with microcontrollers or other similar control circuits.

In the light signaling devices 1 according to the invention, it is not mandatory to arrange the secondary optical elements 4 and the base plate 2 in parallel and spaced relation to each other. Arrangements can also be made in which the base plate 2 forms an angle, for example 90°, with the base plate of the secondary optical element(s) 4. In this case, the emitted light is transmitted to the secondary optical element(s) 4 by a suitably positioned mirror or prism. In this way, light signaling devices according to the invention can be made that can be used, for example, in existing, narrow space conditions.

When sizing the light signaling devices according to the invention or a given light signaling system, the choice of the aforementioned d/a ratio can be adjusted to the subjective requirements regarding the recognizability or non-recognizability of the failure of an individual LED. There is also no obstacle to adjusting the d/a ratio to the lens(es) used as the secondary 4 optical element(s).

As already described above, in the light signaling devices 1 according to the invention, the distance of the light sources, in particular and preferably the LEDs 3, from a secondary optical element 4 is selected such that the largest extent d of the area occupied by the light source(s), in particular the LEDs 3, is significantly smaller than the distance a. Light signaling systems 5 according to the invention can be formed from several light signaling devices 1 according to the invention. By forming suitable electrical connections, high operational safety can be achieved.

Claims (16)

-16Patent claims 1. A light source display element comprising two or more electric light sources arranged in a common plane on a base plate, characterized in that the light sources are arranged on the base plate (2) in an arrangement occupying a surface having a maximum extent (d) and at a predetermined distance (a) from an optical element (4), wherein said maximum extent (d) of the surface occupied by the light sources is chosen to be smaller than the predetermined distance (a). 2. A light source display element according to claim 1, characterized in that it comprises LEDs (3) (light emitting diodes) as light sources. 3. A light source display element according to claim 1 or 2, characterized in that it comprises a parallel connection of two or more electric light sources. 4. A light source display element according to any one of claims 1-3, characterized in that the electric light sources are connected to an electric power source, in particular a current generator (10), which supplies a current (I) regulated proportionally to the input voltage and is capable of modifying the brightness of the remaining light sources in the event of a failure of one light source. 5. A light signaling device, comprising at least one light source display element and at least one optical element according to any one of claims 1-4, characterized in that the at least one optical element (4) is respectively arranged at a defined distance (a) from the associated at least one light source display element, which distance (a) is greater than the largest extent (d) of the area occupied by the light source(s). 6. Light signaling device according to claim 5, characterized in that the optical element (4) is a light source (s) that transmits light rays emitted to one side of the optical element (s) to the -17on the other side, a lens that converts the light into a stream of light that emerges as at least approximately parallel rays. 7. Light signaling device according to claim 5 or 6, characterized in that the distance (a) between the light source(s) and the optical element (4) is at least ten times the largest extent (d) of the area occupied by the light source(s). 8. A light signaling system comprising at least one light signaling device according to any one of claims 5-7, characterized in that, when more than one light signaling device (1) is used, these are arranged in the light signaling system (5) in such a way as to provide equal light path lengths from the individual light sources to the optical elements (4) assigned to them and lying in a common plane. 9. Light signaling system according to claim 8, characterized in that when more than one light signaling device (1) is used, they are arranged in a common plane within the light signaling system (5), on the outer side of the optical elements (4), in an arrangement providing homogeneous light intensity. 10. Light signaling system according to claim 8 or 9, characterized in that when more than one light signaling device (1) is used, their electric light sources, in particular LEDs (3), are connected in parallel with each other in groups, the groups consisting of parallel-connected light sources are connected in series with each other, and an electric energy source, in particular a current generator (10) is connected in series with the groups of light sources connected in series with each other. 11. A light signaling system according to any one of claims 8-10, characterized in that it has a housing (6) containing at least one light signaling device (1). 12. A light signaling system according to any one of claims 8-11, characterized in that the light signaling system (5) comprises a light source (4) on the optical element (4). -18 also includes a primary optical element (7) inserted into the beam path of the light rays passing through, which causes the light rays coming from the optical element (4) to exit the light signaling system (5) in a predetermined distribution. 13. Light signaling system according to claim 11 or 12, characterized in that the first additional optical element (7) comprises a headlight lens mounted on the device housing (6). 14. The light signaling system according to claim 12, characterized in that the light signaling system (5) also comprises an additional or supplementary optical element (8) inserted between the optical element (4) and the primary optical element (7) to suppress or attenuate environmental optical disturbances affecting the light signaling system (5). 15. A light signaling system (5) according to any one of claims 8-14, characterized in that the light source display elements are arranged in the light signaling system (5) in an arrangement displaying certain specific symbols. 16. Light signaling system (5) according to claim 15, characterized in that the light source display elements are arranged in the light signaling system (5) in a variable arrangement suitable for displaying different symbols. The authorized person GÖDÖLLE, KÉKttZsVíESZ^iO^fc TAILOR Patent 1024 =zt5wídalm! manager