Traffic signalling device for selfilluminated display

0001The invention relates to a traffic control signaling device for self-luminous display ACCORDANCE WITH the Preamble of claim 1.

0002For traffic engineering signaling devices with self-illuminating displays such as traffic signals at intersections or variable message signs are now Incandescent or halogen lamps.

0003EP 0467034, for example, a display device known for a variable message signs, in which any ads, the unalterable of at least one display part and an arbitrarily selectable display part assembled are represented. It is not for everyone variable display part separate, illuminated bunch of Optical fibers provided in accordance with their free ends distributed the associated, non-variable display part are arranged in a display panel. The arbitrarily selectable Display part is by means of a processor-controlled matrix array representable of display elements, each display element performed by an illuminated optical fiber is. The illuminated optical fibers are thereby by halogen lamps illuminated. The disadvantage with this method firstly, the short life of halogen bulbs and other their high energy consumption.

0004Therefore sporadically already LEDs for use provided in traffic engineering signaling devices.

0005From EP 0694894 a signal light is known that at least is partially provided with light-emitting diodes which are within the signal light of a first to at least one second Emission are mounted tiltable and pulleys groups can be positioned. Probable Holding device is however rather complicated and not suitable for a simple mounting.

0006It is therefore an object of the invention, a traffic engineering specify signaling device, the known versus the Signaling means a more robust construction and having a longer life.

0007The object is achieved according to a signaling device of the initially named kind with the characterizing Features of patent claim 1.

0008By a suitable holding device to the LEDs on the one hand a good heat dissipation achieved, and on the other resulting from the matched holes in the Front panel of the signal means a simple Mounting and a simple change of defective LEDs.

0009In a preferred embodiment according to claim 2 gives an especially simple exchange or a particularly easy assembly by a thread of the holding device, which in accordance with a pre-formed hole in the front panel is fitted.

0010A preferred embodiment is obtained according to patent claim 3 by a toothing on the holding device, which also a particularly simple assembly of the holding device guaranteed.

0011A further improvement of the thermal conductivity of the holding device is achieved in that according to patent claim 4 the light emitting diode by a curable thermal grease in the Holding device is fixed.

0012According to claim 5 results in an improvement of the optical Radiation characteristics by an optical imaging device, in which the front opening of the holding device is provided.

0013A particularly inexpensive embodiment is obtained by a optical imaging means of a transparent Plastic such as polymethyl methacrylate (PMMA, trade name Plexiglass) or polycarbonate (PC, trade name Makrolon) according to claim sixth

0014Particularly good heat conducting properties are exploited by that according to patent claim 7, the holding device and the Front panel are made of metallic materials.

0015This results also according to claim 8, the preferred Embodiment, directly in only one terminal of the light-emitting diode is contacted, and the other terminal (For example, the ground terminal) electrically connected to the associated retaining device, the retaining device electrically conductively connected to the front panel and the front panel is connected via a cable connection to the control unit. Thereby, the wiring effort is reduced.

0016Special embodiments are defined in the figures of the drawing shown. show case<sl><li>1 shows a schematic cross section through a holding device with an optical imaging device,</li><li>Figure 2 is a schematic cross section through a holding device, wherein one terminal of the light-emitting diode with the holding device is contacted,</li><li>Figure 3 is a schematic cross section through a holding device without optical imaging device and</li><li>Figure 4 is a schematic cross section through a holding device for a light emitting diode mounted on one chip is, with appropriately adapted optical imaging device.</li></sl>

0017In Figure 1 is a section of a faceplate 1 (For example, aluminum) a signaling device, For example, a variable message sign or a Traffic signal represented, in through a hole 2 the front plate 1 is a light-emitting diode 3 emits its light. The light emitting diode 3 is in a tubular according to the invention Holding device 4 mounted such that between the sidewalls of the light emitting diode 3 and the retainer 4 a good contact for heat dissipation is ensured. The Holding device 4 may, for example of a metallic Material or of a plastic with good thermal conductivity be made. The light-emitting diode 3 is mounted in such a way in the holding device 4, that of the LED 3 emitted light through a first opening (Light exit opening 5) of the holder 4 by the Front panel 1 is emitted and the light emitting diode 3 through a second opening of the retainer 4 (Contacting opening 6) is contacted. The cathode terminal 7 and 8, the anode terminal of the light emitting diode 3 are connected via cable links 10 to a control unit 11, which according to Display Ads the LED 3 switches on and off. The anode terminal 8 and the cathode terminal 7 are together with the cable connections 10 by means of a curable thermal compound 12 firmly connected with the thermal grease 12 both a good Heat dissipation as well as a secure fastening of the light emitting diode 3 ensures in the holding device. 4 In the direction the light exit opening 5, the holding device 4 outside threaded 13, corresponding to a Thread is inserted into the bore 2 the front panel of the first This is a particularly well-mounted, optionally detachable connection between the front panel 1 and the Holder 4 achieved. To improve the emission is in the retaining device 4 is an optical imaging device 14 is provided, with the aid of which the radiation characteristic adapt to local conditions, so that the display of all road users well recognized becomes. The optical imaging device 14 is made of glass or of an inexpensive transparent plastic manufactured such as polymethyl methacrylate (PMMA, trade name Plexiglass) or polycarbonate (PC, trade name Makrolon).

0018In figure 2, another embodiment is shown wherein the anode terminal 8 a conductive connection with the Holding device 4 has, in this example made of metallic Material is made. A conductive connection between the holder 4 and also from leaves a metallic material existing faceplate 1 A particularly simple contacting the light emitting diode 3 reached by a cable connection 15 to the front plate 1 is set by the control unit 11 from. This can be the amount of cabling reduce by a factor of two. one terminal (For example, the ground terminal) of all in the signaling device provided light emitting diodes 3 is thus together on the front panel 1 and the holder 4 connected to the control device eleventh The retainer 4 has a gear 9 which is a particularly simple installation guaranteed with the front panel.

0019In Figure 3 is shown schematically and simplified, such as a holder 4 without optical imaging device is arranged.

0020Figure 4 shows an embodiment in which instead of the Light-emitting diode 3 is a light-emitting diode 16 on a semiconductor chip is arranged in a holding device. 4 In the light exit opening 5 of the retainer 4 is a specially adapted to the light-emitting diode 16 on the semiconductor chip optical imaging means 17 is provided. contacting is carried out as in the preceding embodiments, over the cathode terminal 7, and the anode terminal 8 and cable connections 10 to the control unit 11. Also in this embodiment it is possible, a terminal by an electrical Contact on the holder 4 to the front panel 1 execute a reduced number of cable connections to achieve.