EP3296182B1 - Led signal light - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to an LED signal light as it is used in particular in rail traffic in so-called route signals. The invention also relates to a track signal with a corresponding LED signal light.

BACKGROUND OF THE INVENTION

Signal lights of the type in question are, for example, from the DE 10 2010 064 376 A1 , which shows a signal lamp according to the preamble of claim 1, known and find above all as so-called track signals in rail use and then subject to special requirements in terms of safety and radiation characteristics (light intensity distribution), which are specified by the users of corresponding signal lights. The requirements of Deutsche Bahn have been specified and proven to be particularly accurate, so that they are adopted by different signal lamps users worldwide in identical or analogous form. The requirements regularly provide for a specific light intensity distribution which is specified in relation to a so-called main emission direction. The main radiation direction is usually an imaginary horizontal line emerging centrally from the signal, in relation to which the light intensity distribution is specified by the fact that certain light intensities have to be reached by the signal light at certain angles relative to the main emission direction.

Signal lights of the type in question are used both in so-called upper and in so-called lower path signals, wherein lower path signals are signals in which the center of the usually round illuminated signal surface is about 8 to 30 cm above the rail top, while in a upper path signal is the center of the signal surface typically about 360 to 550 cm above the rail top edge.

In order to ensure fail-safe signal lights of the type in question here, so-called two-filament incandescent lamps were formerly used in which could be switched to another filament after failure of a filament. Due to the various advantages of LED technology and, above all, the fact that LED luminous flux has increased dramatically, two-lamp incandescent bulbs are gradually replaced by LED modules, some of which are designed to be classic Two-filament incandescent lamp simulate, since the replacement of the corresponding control electronics would be associated with considerable effort. An example of an LED signal lamp with separately controllable in the manner of a two-filament incandescent strands of series-connected LEDs shows the EP 1 992 542 B2 which also explains a typical light intensity distribution with respect to the main emission direction.

In order to ensure not only reliability in LED signal lights, but to produce different colored signals by means of a single signal lamp, various LED signal lights have been proposed with adjacently arranged LEDs of different colors, for example in the DE 10 2015 218 156 A1 , the EP 2 708 803 A1 and the EP 2 708 808 A1 , The three last-mentioned documents pursue the concept of simultaneously switching on the LEDs of one color and sensor-monitoring the radiated light in order to increase the current supplied to an LED if necessary in order to compensate for any decrease in the luminous intensity of another LED.

A so far unsatisfactorily solved problem with LED signal lights is the so-called phantom light, which is caused by external to the signal light incoming light and causes the signal light at least under certain viewing angles appears as if they (in multi-colored signal lights, if necessary in one certain color).

In the case of LED signal lights, such phantom lights are produced in particular by light which falls from the outside through the built-in optics onto the individual LEDs and is reflected there, which is why in the prior art it is regularly attempted to arrange the boards as deep as possible in a luminaire housing and housing exteriorly barges and houseineinseitig various apertures too to reduce phantom light effects. The EP 0 860 805 A1 proposes to arrange a Fresnel lens a specially trained scattering lens of the same diameter, which should deflect the emitted light down, so that at least when the sun is high, sunlight should not be able to reach the LEDs. The DE 10 2010 024 381 A1 proposes to pre-allocate a special optical fiber segment to a Fresnel lens in order to divert a partial light flow into a so-called near-field.

However, the previously known measures for the reduction of phantom light lead to the fact that corresponding LED signal lights do not have the desired compactness. In addition, the known measures under particularly stringent test requirements, for example, irradiation of light from an angle just above the Hauptabstrahlrichtung, so for example from an angle of 10 degrees obliquely from above into the LED signal, not yet satisfactory.

DISCLOSURE OF THE INVENTION

The invention is based on the object of specifying an improved with regard to the reduction of phantom light effects LED signal light.

The object is achieved by an LED signal lamp with the features of independent claim 1. The independent claim 13 relates to a track signal for rail traffic with an LED signal lamp according to the invention.

It has surprisingly been found that by "tilting" the optical axis of those portions of the optical components used for the recording and bundling of the light emitted by the LEDs in operation, the homogenization of the recorded and collimated light and the collimation of the homogenized light to ± 3 to 8 degrees, preferably 5 to 6 degrees to Hauptabstrahlrichtung an excellent reduction of can be achieved on the basis of the usual, for example, given by Deutsche Bahn test criteria measured phantom light effects.

The LED signal light according to the invention is particularly compact and, in an advantageous development, not only makes it possible to configure the LEDs provided for generating signal light of a specific color redundantly and separately, but also to provide separately controllable LEDs of different colors, so that with a corresponding LED Signal lamp different signal images can be generated. In addition, the LED signal light according to the invention can easily be designed so that it can be used both at upper and at lower range signals. This makes it possible for the invention to provide a "universal LED signal light", which can be manufactured in large quantities and therefore cost-effective and can meet a wide variety of user-side application requirements while high reliability. Further details and advantages of the invention will become apparent from the following purely exemplary and non-limiting description of embodiments in conjunction with the drawings comprising eight drawing figures.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1

shows in a highly schematic form essential elements of an LED signal lamp according to the invention in vertical section along the main emission direction.

Fig. 2

shows an optical device according to Fig. 1 in plan view.

Fig. 3

shows a holding plate according to the invention for the optical component according to Fig. 2 in a perspective view, seen from the light exit side of the signal light on the retaining disc.

Fig. 4

shows the back of the retaining disk according to Fig. 3 in perspective view.

Fig. 5

shows an optical component for collimating and scattering the homogenized light in perspective view obliquely on the light exit side of the device.

Fig. 6

shows the device according to Fig. 5 in side view.

Fig. 7

shows various exemplary arrangement possibilities of six single or multi-colored LEDs in a signal lamp according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

In Fig. 1 is shown in its entirety with 10 designated LED signal light, the Fig. 1 the signal lamp for the basic understanding of the invention is highly schematic, while Fig. 2 the so-called first optical component in plan view shows.

• eine Platine 12, auf der eine Anzahl von LEDs 14 in einer Reihe nebeneinander angeordnet sind,
• ein erstes optisches Bauelement 16, das über Abschnitte 18, von denen aus Gründen der Übersichtlichkeit nur einige mit Bezugszeichen versehen wurden, zur Aufnahme und Bündelung des von jeweils einer LED 14 abgestrahlten Lichts und einen integral an die Abschnitte 18 zur Aufnahme und Bündelung angeformten quaderförmigen Abschnitt zur Homogenisierung des Lichts verfügt,
• eine Haltescheibe 20, die eine Doppelfunktion im Hinblick auf die Halterung des ersten optischen Bauelementes 16 und die Verhinderung von Phantomlichtreflexen erfüllt,
• ein zweites optisches Bauelement 22, das über einen Abschnitt zur Kollimierung des aus dem ersten optischen Bauelement austretenden homogenisierten Lichts und einen Abschnitt zur Streuung des Lichts verfügt,
• eine Abschlussscheibe 24, die unmittelbar benachbart zur Lichtaustrittsseite des zweiten optischen Bauelementes 22 angeordnet ist, sowie
• ein durch die gepunktete Linie angedeutetes Gehäuse 26.

The LED signal lamp 10 includes in this embodiment

• a circuit board 12, on which a number of LEDs 14 are arranged in a row next to one another,
• a first optical component 16, which has been provided for the sake of clarity, only a few reference numerals for receiving and bundling of the light emitted by one LED 14 sections and 18 integrally formed on the sections 18 for receiving and bundling cuboidal section to homogenize the light,
• a holding disk 20 which performs a dual function with regard to the mounting of the first optical component 16 and the prevention of phantom light reflections,
• a second optical component 22 having a portion for collimating the homogenized light emerging from the first optical component and a portion for diffusing the light,
• a cover plate 24, which is disposed immediately adjacent to the light exit side of the second optical component 22, as well as
• a direction indicated by the dotted line housing 26th

Not shown is a per se known, on the side facing away from the LEDs 14 side of the board arranged heat sink with a number of cooling fins.

As in Fig. 1 The dot-dashed optical axis 30 of the sections for receiving and focusing the light emitted by the LEDs, for homogenizing the recorded and collimated light and for collimating the homogenized light by an angle α of about 5.5 degrees vertically downwards, is clearly discernible tilted relative to the main emission direction 32. It should be noted that in the drawing for clarity, the optical axis 30 was also pulled through the light scattering section and generating the desired light intensity distribution of the optical device 22, while this section is straight, the light generated by the LED in the shown situation to break down, so compensate for the tilting of the optical axes of the three sections mentioned.

As indicated by the two-dot chain line 34, which represents a surface normal of the lens 24, the lens is also inclined against the Hauptabstrahlrichtung 32, in such a way that their surface normal 34 with the main radiation 32 at an angle β of 15 degrees in the same direction of rotation in which also the optical axis 30 of the sections for recording and bundling, homogenization and collimation deviates from the main emission direction.

As in Fig. 1 In this embodiment, the board 12 is also inclined to the main emission direction 32, so that at least the side of the board 12 facing the light exit side of the signal light 10 is perpendicular to the optical axis 30 of the sections for receiving and bundling the light emitted by the LEDs. which favors the design of these sections for inclusion and bundling.

In Fig. 1 the situation is shown in which the LED signal light 10 is to be used as the upper path signal. The individual light exit surfaces of the scattering section of the optical component 22, the function of which will be discussed below, diffuse light generated by the LEDs substantially into an angle range of approximately 1 degree upward and approximately 34 Degrees down with respect to the main emission direction 32, as well as to meet customer-specific requirements to varying degrees laterally of the optical axis 30, so that a train driver the signal not only from the front and obliquely from below, but also, for example, when cornering from can see well at a certain angle diagonally from the side. The requirements to be met by such a path signal with regard to the light intensity distribution are known to the person skilled in the art and can be met by him by appropriate design of the individual scattering surfaces on the light exit side of the optical component 22.

A peculiarity of the embodiment of a signal light 10 according to the invention shown here is that it can be used by a simple rotation through 180 degrees about an axis passing through the main emission direction 32 both as an upper path signal and as a lower path signal. In the latter case, the light is then scattered from the individual light exit surfaces of the diffusing section of the optical component 22 down to an angle range of about 1 degree to about 34 degrees with respect to the main emission direction 32.

This in Fig. 2 shown embodiment of an optical device 16 is for use with six in a row next to each other on the in Fig. 1 shown board 12 arranged LEDs formed. The LEDs may be, for example, six green, four blue and two white, four yellow and two white, or four red and two white LEDs, which may be advantageous according to one of the in FIGS Fig. 7 can be arranged, which will be discussed below.

In the embodiment shown, each LED of each color has at least two separately controllable LEDs, it being possible, for example, to switch between the LEDs each time a specific signal color is switched on in order to achieve uniform wear of all LEDs of the same color. Advantageous ways and ways of driving the individual LEDs are, for example, in the aforementioned EP 1 992 542 B described, to the disclosure of which reference is made.

In this exemplary embodiment, the optical component 16 comprises six sections 18 which are each designed to receive and bundle the light emitted by one of the LEDs. Here, the term bundling is understood to mean the reduction of the emission angle of the LEDs, which may comprise almost 180 degrees, depending on the type of LED used, so that as much of the emitted light as possible can be picked up and used to generate a light signal.

The sections 18 are integrally formed on a substantially parallelepiped-shaped section 36 for the homogenization and optionally thorough mixing of the LED light entering the optical component 16 via the sections 18. The section 36 blurs virtually the place of origin of the incident light, so that its light exit surface 38 appears almost uniformly illuminated, regardless of whether one or more LEDs are turned on, so that then the light exit surface of the signal light also appears uniformly illuminated and, if as in this Ausführungsbespiel of each LED of each color at least two separately controllable LEDs are available, for one and the same color also gives a virtually identical light distribution.

The optical component 16 has in this embodiment further comprises two integrally formed on the component, here substantially cylindrical alignment elements 40, which are provided with receiving bores for one fastening screw and at their respective end facing the board over a substantially cylindrical, reduced in diameter Passport portion 44 have, the outer profile is at least partially complementary to the inner profile of a corresponding fitting bore in the board 12. This allows a simple and particularly precise installation of the optical component 16 on the circuit board 12, wherein by the diameter reduction of the fitting portions 44 on the alignment elements 40 bearing surfaces for the circuit board 12 are formed. The optical component 16 can be manufactured inexpensively from suitable plastics as a high-precision plastic injection-molded part.

In the FIGS. 3 and 4 the retaining disk 20 is shown from two perspectives. This holding disc 20 advantageously performs a dual function: on the one hand it has via a slot 46, the inner contour exactly to the outer contour of the cuboid portion 36 of the example in the FIGS. 3 and 4 shown optical component 16 is adapted so that it allows an exact guidance and support of this section. On the other hand, it is at least light-absorbing colored on its side in the intended mounting state of the light exit side of the signal light side, in particular black, so that it absorbs incidental light in large part, and also has a substantially scattering reflective portion 48 and one with a structure for directional reflection provided portion 50, which may be polished. This embodiment advantageously contributes to the further reduction of phantom light, since then, when the signal light as in Fig. 1 is shown as the upper signal light is used, which is provided with the directionally reflective structure provided portion 50 in the lower half of the signal lamp, can get into the obliquely from above from the outside incident light. The structure then reflects the portion of the light that is not absorbed by the retaining disc, targeted upward from the signal light, so that it can not be perceived under the typical viewing angles. On the other hand, when the signal lamp is turned 180 degrees by an axis passing through the main radiation direction 32 as described above and used as the lower signal light, the scattering reflective portion 48 of the holding plate 20 is in the area where light incident obliquely from outside into the signal lamp is located can hit the retaining disc, so that the part of the light that is not absorbed by the retaining disc, scattering reflected and also directed away from the viewer. The effect can advantageously be enhanced by the fact that the inside of the housing 26 is provided with a light-absorbing layer.

In the FIGS. 5 and 6 is shown from various perspectives in its entirety designated 22 optical component, which in this embodiment of an LED signal lamp according to the invention both the section for collimating the homogenized light and the portion for scattering the homogenized light to achieve a relation to a predefined main emission predetermined light intensity distribution as integral components.

As in particular in Fig. 6 In this exemplary embodiment, the collimating section is formed by a convex section 52 having a focal point which is located in the region of the light exit surface 38 (FIG. Fig. 2 ) of the optical component 16 is located and parallelizes the arriving via the optical component 16 LED light.

The optical component 22 has in this embodiment also has a portion 54 for scattering, in the side view of Fig. 6 is wedge-shaped and its light exit side is provided with a plurality of suitably shaped light exit surfaces 56, which scatter the parallelized light in the user-specified manner so as to give the desired light distribution. In the individual light exit surfaces 56 are free-form surfaces, which in the merely schematic representation of FIGS. 5 and 6 Although they look identical, they are actually calculated and designed individually based on the user's specifications.

The integration of the sections for collimation and for scattering in a single optical component 22 advantageously contributes to the compact design of the signal light according to the invention.

In the Fig. 7 are purely by way of example and not limitation, four different in each case advantageous arrangements of each six LEDs in series shown side by side.

The arrangement a) comprises two red LEDs R1, two red LEDs R2 and a white LED W1 and a white LED W2. In this case, the two red LEDs R1 are connected in series as well as the two red LEDs R2, so that the red LEDs R1 and the red LEDs R2 each form a strand, which can be controlled separately. The two white LEDs W1 and W2 can also be controlled separately.

As shown, the arrangement of the six LEDs is advantageously made such that the spacing between the LEDs of each strand is maximized. In the present case, there are three other LEDs between the two LEDs R1, as well as between the LEDs R2 of the other strand. By this arrangement is ensures that the thermal effects of the LEDs of one strand on each other during operation of the strand are minimized.

The illustrated arrangement a) can serve as a so-called "signal light red-white", as used in the so-called "70 mm design" (diameter of the illuminated area on the lens of the signal) ", for example, by Deutsche Bahn R1, R2, W1 and W2 can each be controlled separately, so that either only the two LEDs R1, only the two LEDs R2 or only one of the LEDs W1 and W2 are lit. If the LEDs are functioning, then the other LED or string can be activated in case of malfunction, making the LED indicator light fail-safe.

To increase the life of the signal light by uniform wear of the LEDs can be provided that the LEDs or LED strands are alternately turned on, that is, after operation of the strand with the LEDs R1 then when the next time a red signal is to be generated , first the string with the LEDs R2 is turned on (if this does not show a malfunction).

In an analogous manner, in the arrangements b) and c) two colored LEDs in a string are connected in series, namely in the arrangement b) two yellow LEDs Y1 and two yellow LEDs Y2 or in the arrangement c) two blue LEDs B1 and two blue LEDs B2. Both arrangements b) and c) each also comprise two white LEDs W1 and W2 and can be operated analogously to the manner previously described for arrangement a) as "signal light yellow-white" or "signal light blue-white".

The arrangement d) shows an arrangement in which three green LEDs G1 and three green LEDs G2 are connected together in each case to a separately controllable strand. Depending on the required light intensity, it may be sufficient in such an arrangement, if a strand comprises only two green LEDs.

The exemplary arrangement of six LEDs side by side is ideal for the production of said "70mm signal". Operators such as Deutsche Bahn also use larger signals, for example a so-called "136mm signal". For such a signal, an arrangement could be used with eg two mutually parallel rows of eight to twelve, preferably ten juxtaposed LEDs, which can then comprise LEDs of two or even three colors, and advantageously wherein the LEDs of each color redundant and so separately can be provided controlled that for each color at least one spare LED or a spare string consists of several LEDs. It is understood that for other signals arrangements with more than two rows can be provided. Here, too, the arrangement of the individual LEDs is advantageously made such that the spacings of the LEDs of one and the same strand or, in other words, the spacings of those LEDs which are lit simultaneously depending on the desired signal image, are maximized. Instead of in the FIGS. 5 and 6 The optical component shown in FIG. 1, which includes both the homogenized light collimating portion and the homogenized light scattering portion, may be realized by separate components. The section shown for collimation may also be provided by a Fresnel lens.

LIST OF REFERENCE NUMBERS

10

LED signal light

12

circuit board

14

LED

16

optical component

18

Section for inclusion and bundling

20

retaining washer

22

optical component

24

lens

26

casing

30

optical axis

32

main radiation

34

Surface normal of the lens

36

cuboid section

38

Light-emitting surface

40

aligning

44

fitting portion

46

slot

48

scattering reflective section

50

Section with directionally reflecting structure

52

convex section for collimation

54

wedge-shaped section for scattering

56

Light-emitting surface

α, β

corner

B1, B2

blue LED

G1, G2

green LED

W1, W2

white LED

Y1, Y2

yellow LED

Claims (13)

1. An LED signal light (10) in particular for the rail traffic with a number of LEDs (14) and a number of optical components (16, 22) with sections (18, 36, 52, 54) for

   - receiving and bundling the light emitted by the LEDs (14) during operation,

   - homogenizing the received and bundled light,

   - collimating the homogenized light and

   - scattering the homogenized light to achieve a light intensity distribution predetermined with respect to a predefined horizontal main emission direction (32),

   characterized in

   - that the optical axis (30) of the sections (16, 32, 52) for receiving and bundling, homogenizing and collimating the light emitted by the LEDs (14) in the intended mounting state of the signal light (10) deviates by an angle of ± 3 to 8 degrees, preferably 5 to 6 degrees vertically from the main emission direction (32).
2. The LED signal light (10) according to claim 1, characterized in that the LEDs (14) can be controlled independently.
3. The LED signal light (10) according to claim 2, characterized in that at least two independently controllable LEDs (R1, R2) of a first colour and at least two independently controllable LEDs (W1, W2) of at least one further colour are provided.
4. The LED signal light (10) according to claim 3, characterized in that multiple LEDs (G1) of one colour are connected in series in a string and can be controlled independently of a string of series-connected LEDs (G2) of the same colour.
5. The LED signal light (10) according to claim 4, characterized in that the LEDs (G1; G2) of one string are arranged in a row or in two or more rows next to each other on a printed circuit board (12) such that the distances between the LEDs (G1; G2) of the same string are maximized.
6. The LED signal light (10) according to claim 5, characterized in that at least the side of the printed circuit board (12) facing the light exit side of the LED signal light (10) is perpendicular to the optical axis (30) of the sections (16, 18) for receiving and bundling the light emitted by the LEDs (14).
7. The LED signal light (10) according to any one of claims 1 to 6, characterized in that the sections (18) for receiving and bundling the light emitted by the LEDs (14) and for homogenizing the received and bundled light are integrated in an optical component (16), which has a cuboid section (36) for homogenizing and a number of sections (18) formed thereon corresponding to the number of LEDs (14) for receiving and bundling the light emitted from each LED.
8. The LED signal light (10) according to claim 7 and one of claims 5 or 6, characterized in that the optical component (16) with the sections (18) for receiving and bundling the light emitted from each LED further has at least two alignment elements (40) for determining an exact position of the optical component (16) with respect to the printed circuit board (12), and the printed circuit board (12) is provided with at least two dowel holes for each section (44) of the alignment elements.
9. The LED signal light (10) according to claim 7 or 8, characterized in that a support plate (20) is provided with a receiving slot (46) for the homogenizing cuboid section (36) of the optical component (16), wherein at least the side of the support plate (20) facing the light exit side of the signal light (10) is extending perpendicularly to the optical axis (30) of the homogenizing cuboid section (36) and has a light-reflecting section (50) and a section (48) provided with a light scattering structure.
10. The LED signal light (10) according to any one of claims 1 to 9, characterized in that the sections (52, 54) for collimating and scattering are integrated in an optical component (22) that has a convex section (52) for collimating the light exiting from the section (36) for homogenizing and a section (54) integrally formed thereon having a plurality of light exit surfaces (56) to achieve the predetermined light intensity distribution.
11. The LED signal light (10) according to any one of claims 1 to 10, characterized in that the LEDs (14) and the optical components (16, 22) are fixed in a housing which by a 180-degree rotation about an axis extending in the main emission direction (32) allows the use of the LED signal light (10) as both upper and lower signal lights in track signals of the rail traffic.
12. The LED signal light (10) according to claim 11, characterized in that the light exit side of the housing is closed by a closing disc (24) directly arranged in front of the section (54) for scattering the collimated light, wherein the surface normal of said closing disc is inclined by an angle of 14 to 16 degrees to the main emission direction (32) in the same direction as the optical axes (30) of the sections (18, 36, 52) for receiving and bundling, homogenizing and collimating.
13. A track signal for the rail traffic comprising at least one LED signal light (10) according to any one of claims 1 to 12.

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