FR2986603A1 - Illuminated signaling marker for use in e.g. car to produce illumination to other vehicle drivers during emergency situation, has cavity arranged such that flow forms directional flow according to secant plane with axis and passes by stud - Google Patents

Abstract

The marker (80) has a support (100) on which a light source (101) is mounted for providing a luminous directional flow directed according to a predetermined optical axis (102). A refractive optics (104) forms, with the support, a cavity around the light source. The cavity is arranged to redirect the luminous flow on 360 degrees around the stud such that the flow forms a directional luminous flow directed according to a predetermined plane (105), which is a secant plane with the predetermined axis and passes by the stud.

Description

BACKGROUND OF THE INVENTION The present invention relates to a light signaling pad (or may be referred to hereinafter merely as a "signaling pad"). These light pads can be provided fixed and / or mobile. Such a light signaling pad can be in particular: a stud located on a motor vehicle such as a car or a motorcycle, and actuated to produce lighting when the vehicle must signal to other drivers an emergency situation (for example ambulances, police or gendarmerie vehicles, fire-fighting vehicles announcing their passage in an emergency situation); a plot that can be placed on the road or on a vehicle to signal an event such as a road accident, work on the road, a slowdown in traffic, etc. The present invention relates more particularly to 360 ° luminous signaling pads. They provide directional lighting oriented preferably parallel to a single plane, and 360 ° (ie radians) around the signaling pad. The field of the invention is more particularly, but without limitation, that of emergency road signage.

STATE OF THE PRIOR ART In the prior art, the so-called "classical" beacons are known, comprising: a source of white light; a first mask blocking the light on the top of the stud so as to let through only a luminous flux called "remaining", constituted by the portion of the luminous flux oriented preferentially parallel to a single plane over 360 ° around the signaling pad; ; and -2- - a motor driving in rotation a second cover so as to pass at any moment only part of the remaining luminous flux. A hull covering the assembly determines the color of the luminous flux emitted by the beacon, for example orange for work or blue for the police. A major disadvantage of these so-called classic beacons is the loss of light energy caused by the presence of caches, including the first cache. These light losses result in high energy consumption. "LED" beacons are also known. These beacons comprise many (several tens) light-emitting diodes (LEDs) evenly distributed over the entire lateral surface of a cylinder. These LED beacons, however, also have a high energy consumption due to the presence of multiple LEDs. An object of the present invention is to provide a light signaling pad providing a luminous flux oriented preferably parallel to a single plane 360 ° around the signal pad, and which has an optimized power consumption. SUMMARY OF THE INVENTION This object is achieved with a light-signaling pad 25 comprising a support, on which a light source is mounted providing a directional luminous flux directed along a predetermined optical axis. The light signaling pad further comprises a refractive optics forming with the support a cavity around the light source, and arranged to redirect said luminous flux: over 360 ° around the signaling pad and so that this flux forms a directional luminous flux oriented according to a predetermined plane, which plane is secant with said predetermined optical axis and passes through the light signaling pad. Said cavity is preferably closed. Since the luminous flux emitted by light source is not partially closed off, but instead redirected, the light and therefore energy losses are minimized.

In addition, the light signaling pad makes it possible to use only a limited number of LEDs, where appropriate only one, which allows the production of a light-signaling pad having a minimized energy consumption. This results in a luminous signaling pad illuminating 360 ° around it and whose energy consumption is optimized, which is particularly advantageous not only for obvious questions of energy cost and protection of the environment, but also because the light signaling pads are generally intended to operate autonomously, without being connected to an external source of energy. A device having a long duration of autonomy during which it is not necessary to connect it to any external energy source other than an onboard energy source is obtained. In addition, according to the invention, the luminous flux is homogeneously distributed over 360 ° around the signaling pad, unlike the devices of the prior art using a light source by illumination direction. The luminous signaling pad according to the invention can be produced economically since it only requires the presence of a very limited number of elements, unlike the devices of the prior art using a light source by direction of light. 'lighting. The light signaling pad according to the invention is also particularly robust. Indeed, it presents no mechanical system in motion. In addition, it is formed in one piece, and the light source 30 is entirely enclosed within a cavity which protects it from bad weather in particular. The light signaling pad according to the invention may have a block shape, that is to say a form particularly resistant to shocks. The luminous signaling pad according to the invention preferably comprises a source of embedded energy, advantageously a source of rechargeable energy.

The refractive optics is advantageously arranged to redirect said luminous flux according to an aperture angle cone less than 30 °, said aperture angle being measured in any plane orthogonal to said predetermined plane. Refractive optics therefore also provide a light concentration function.

Preferably, the predetermined optical axis is orthogonal to said predetermined plane. This produces a luminous signaling device having a cylindrical symmetry, the refractive optics then being more easily machinable.

The light source may comprise at least one light emitting diode (LED). In a non-limiting version, they can be placed in the same plane, next to each other or distributed over a circle with a diameter of less than 10 cm.

According to a particularly advantageous "economic" embodiment of the invention, the light source comprises a light generating energy device and the light signaling pad further comprises: a rechargeable energy source, and switching means between a transmission configuration in which the light source is electrically powered by the rechargeable power source and a reception configuration in which the light source electrically supplies the rechargeable power source. It is thus also possible to exploit the energy-generating properties of a light device, to compensate for the self-discharge of a rechargeable energy source which then forms an on-board power source according to the invention. This embodiment is particularly clever in that the discharge of the same source of energy is compensated for as that which electrically supplies the light source. This produces a luminous signaling pad whose autonomy is preserved over time, when the rechargeable energy source does not electrically power the light source. Such a light signaling pad also has the advantage of being compact and compact, since the power supply functions of the light source and of the compensation of the discharge of the energy source are carried out thanks to a number of reduced components. This embodiment is therefore particularly advantageous since it further optimizes the energy consumption of the light signaling pad according to the invention. The energy generating light device is formed for example by at least one LED. A property of a light-emitting diode is thus cleverly exploited, which is: a light source when it is polarized in forward direction or forward direction (a light-emitting diode is in effect a PN junction which must be forward biased when we want to emit light); light detector when polarized in opposite direction or blocking direction. However, it turns out that a light-emitting diode, polarized in the opposite direction and receiving a light flux such as daylight, is a source of current. An idea underlying the economic embodiment of the invention is then to exploit the properties of the current-source light-emitting diode to compensate for the self-discharge of a rechargeable energy source. Preferably, in the receiving configuration of the economical embodiment, the voltage across the light source is greater than or equal to the voltage across the rechargeable power source. This facilitates the passage of the current from, for example, the light-emitting diode through the rechargeable energy source. The light signaling pad according to the economical embodiment of the invention may comprise a voltage conversion circuit connected, in the receiving configuration, between the light source and the rechargeable energy source. This voltage conversion circuit converts the voltage supplied by the light source so that it is possible to obtain a voltage across the light source greater than or equal to the voltage across the power source. rechargeable. The conversion assembly can also be used to regulate the current supplied by the light source. The conversion assembly can be formed by a type of "boost" mounting. We also speak of voltage booster converter, or parallel chopper. It can be provided that the light source according to the invention comprises at least two light emitting diodes connected in series or in parallel. It is advantageous to provide light-emitting diodes 20 connected in series, and to mount as many light-emitting diodes in series as necessary to obtain a voltage across the light source greater than or equal to the voltage at the terminals of the rechargeable energy source. The rechargeable power source may include at least one of: a lead-acid battery; a nickel-cadmium battery; a nickel-metal hydride battery; A lithium battery; a bromine battery; a rechargeable alkaline battery. More generally, the rechargeable energy source may comprise any element capable of maintaining an electrical energy within it. The signaling pad in the economical embodiment may comprise: control means for switching the light signaling pad, alternately in the transmit pattern and in the receive pattern; in the reception configuration, means for measuring a light intensity received by the light source; in the transmission configuration, means for controlling the rechargeable energy source as a function of the light intensity measured by the measuring means of a received intensity. Preferably, the control means implement a periodic switching with a ratio greater than unity between the duration during which the signaling pad is in the transmission configuration and the duration during which it is in the reception configuration. . It is thus possible to adapt the light intensity emitted by the light source to a light intensity received by this light source. When the signaling pad according to the invention is in a low light environment (for example at night, at dusk, on cloudy days, under a tunnel, etc.), it is not necessary that the intensity light emitted by the light source is high to provide good visibility of the signal pad. In addition, said luminous intensity is preferably reduced, under low ambient lighting conditions, to avoid any glare. When the signaling pad according to the invention is in a bright environment (for example in daylight), it is necessary that the light intensity emitted by the light source is high, in order to offer good visibility of the signaling pad. Thus, a luminous signaling pad is obtained which at all times provides optimum illumination, perfectly adapted to the ambient lighting conditions. Thus, a luminous signaling pad having an optimized energy consumption is obtained, since the power consumption of the light source is not higher than necessary. DESCRIPTION OF THE FIGURES AND EMBODIMENTS Other advantages and particularities of the invention will appear on reading the detailed description of implementations and non-limiting embodiments, and the following appended drawings: FIG. 1 illustrates a perspective view of a support and a light source according to the invention; - Figure 2 illustrates a schematic sectional view of a first embodiment of light signaling pad according to the invention; FIG. 3 illustrates a perspective view of a refractive optic of the first embodiment of light signaling pad according to the invention; FIG. 4 illustrates, as a function of time, the voltage at the terminals of an unused rechargeable energy source; FIG. 5 illustrates, as a function of time, a so-called self-discharge current of the unused rechargeable energy source; FIG. 6 illustrates, as a function of time, a compensation current of the self-discharge of the unused rechargeable energy source; FIG. 7 illustrates a part of a second embodiment of light signal pad 20 according to the invention; FIG. 8 illustrates the part of a second embodiment of light signaling pad, as shown in FIG. 7, in the transmission configuration; FIG. 9 illustrates the part of a second embodiment of light signal pad 25, as shown in FIG. 7, in the reception configuration; FIG. 10 illustrates a detail of the portion of the second embodiment of light signaling pad shown in FIG. 7; and FIG. 11 illustrates an advantageous variant of the portion of the second embodiment of luminous signaling pad according to the invention as illustrated in FIG. 7. First of all, a reference will be made to FIG. support 100 and a light source 101 of a first embodiment of light-signaling pad 80 according to the invention. The support 100 makes it possible to rest the light signaling pad 80 according to the invention on a surface. It houses an electronic card on which is mounted the light source 101, control electronics of the light source 101, and an on-board power source (not shown) formed for example by a lithium-ion battery. The lithium-ion battery allows operation of the control electronics of the light source 101, as well as the power supply of said light source 101.

The light source 101 is preferably formed by at least one light-emitting diode having: a semiconductor chip 3 (see FIG. 2), emitting a luminous flux preferentially directed along an axis 102 perpendicular to the plane of the chip, a primary optic 103 (see FIG. 2) returning the luminous flux emitted by the LED in a large emission cone and preferentially along the axis 102, and electrical connections (bonding, etc.). It will be specified here that a bonding designates, in a semiconductor component, a wire soldered between a connection pad and an electronic chip, or between two connection pads. The axis 102 is generally coincident with the vertical axis when the signal pad 80 rests on a horizontal surface. The light emitted by the light source is preferentially directed along the axis 102, and in a cone having an opening angle O of between 80 ° and 140 °, for example about 120 °. The power-emitting diode according to the invention is preferably of CREE XPE LED type, marketed by the American manufacturer CREE. This example is subject to change, in particular according to the 30 technological advances. The color of the emission beam emitted by the light-emitting diode will be chosen according to the desired application for the light-signaling pad 80 according to the invention. The primary optic 103 may be for example glass or plastic, or any material providing good light conduction. A primary optic 103 may be provided for each light-emitting diode forming the light source 101, or a primary optic 103 common to each light-emitting diode forming the light source 101. The basic idea of the invention consists in placing a single optic refractive 104 (see FIG. 2) above the light source 101. The refractive optic 104 forms with the support 100 a closed cavity around the light source 101. The refractive optic 104 is arranged to redirect the light flux emitted by the light source 360 ° around the signal pad 80, and 15 according to a directional flow oriented along a predetermined plane 105 (see FIG. 1) orthogonal to the axis 102. The predetermined plane 105 is a horizontal plane when the signaling 80 rests on a horizontal surface. The predetermined plane 105 passes through the signaling pad 80, typically between a third and two thirds of its height. The refractive optic 104 also makes it possible to concentrate the luminous flux emitted by the light source so that it has an aperture cone 13 of the order of 10 ° or less (5 ° for example), measured in any plane. orthogonal to the plane 105. The refractive optic 104 thus provides two functions: a function of distribution of the light over 360 ° around the luminous signaling pad, and a function of concentration of the light. Refractive optic 104 is, for example, a thermoplastic material such as PMMA (polymethylmethacrylate). This material has the advantage of offering high resistance to temperature and ultraviolet radiation. In particular, refractive optics 104 can withstand a temperature of 220 to 378 degrees Fahrenheit. The refractive optic 104 is formed by molding and in one piece.

FIG. 3 illustrates a particular embodiment of a refractive optic 104 which is in the form of a sphere portion 1041 on which a cone portion 1042 is concentrically superimposed. Such a refractive optic is, for example, of the LEDIL mark, marketed under the reference CA11248_Strada-S-RE-tape, by the company LEDIL (http: //www.ledil.fin.) It then has a length 1043 of 19.6 mm, a width 1044 of 15.5 mm, and a overall height of 7.2 mm In general, the dimensions of the refractive optics 104 are smaller than 20 * 20 * 15 mm 3.

This refractive optics is intended to provide the most uniform light distribution possible over 360 ° around the light signaling pad according to the invention. The light signaling pad according to the invention may be capped by a housing (not shown) at least partially translucent or transparent, to let the light emitted by the light signaling pad according to the invention. The translucent or transparent portion may optionally be colored. The housing has for example the shape of a cylinder with a diameter of 100 mm and a height of 35 mm.

We will now present a second particularly advantageous embodiment of a signal pad according to the invention. According to this embodiment, an energy generating light device is selected as the light source, and the light source 25 is supplied with a rechargeable energy source. Throughout the remainder of the description of the figures, an energy-generating light device will be taken as an example of a light-emitting diode. This example, however, should not be considered as limiting. The at least one light-emitting diode then forms the light source 101 according to the invention, and the rechargeable energy source corresponds to the on-board power source (not shown in the preceding figures). FIG. 4 illustrates, as a function of time t, the voltage Tbat at the terminals of an unused rechargeable energy source (that is to say, not connected to a device to supply energy). It can be seen that the voltage Tbat tends to decrease over time, even when the rechargeable power source is not used. Typically, this voltage decrease is 0.8 V per year. FIG. 5 illustrates, as a function of time t, a current Idec (solid line) called the self-discharge current of the unused rechargeable energy source. It is this self-discharge current which is at the origin of the reduction of the Tbat voltage at the terminals of the unused rechargeable energy source. The self-discharge current is almost constant at the IA value (dashed line). Typically, a value of this discharge current is 0.1 pA. So we see that when it is not used, the rechargeable energy source sees its autonomy decrease over time. FIG. 6 illustrates, as a function of time t, a compensation current Icomp of the self-discharge of the unused rechargeable energy source. The compensation current is constant at the value IB substantially equal to or greater than IA. An idea for further optimizing the energy consumption of the light-signaling pad according to the invention consists in producing this Icomp compensation current from at least one light-emitting diode, otherwise used to produce a light intensity when it is electrically powered. by the rechargeable energy source. Part of this second so-called "economic" embodiment of the invention will be described with reference to FIG. 7. The signaling pad 80 then comprises in particular: a light source 101 formed by a light-emitting diode, a rechargeable energy source 4 formed by a battery, and switching means between a transmission configuration in which the light source 101 is electrically powered by the rechargeable energy source 4 and a reception configuration in which the light source 101 electrically supplies the rechargeable energy source 4. The switching means 5 are formed in FIG. 7 by at least one switch, controlled by pilot means (not shown). The control means make it possible to turn on the light signaling pad 80, that is to say to move it from the reception configuration to the transmission configuration. In this embodiment, the primary optic 103 also allows, in cooperation with the refractive optics 104, the concentration toward the light-emitting diode of the surrounding light intensity when the signaling pad is in the receiving configuration.

FIG. 8 illustrates said part of the economic embodiment of the invention as represented in FIG. 7, in the transmission configuration 1 ', that is to say when the rechargeable energy source 4 electrically supplies the light source 101. The arrows 50 symbolize a light emission by the light emitting diode. The rechargeable energy source 4 is connected to the light source 101 via a block 51 of current regulation. The current regulation block 51 will not be described further here since it is a known element in a power supply device of a light emitting diode. Indeed, it is essential to take into account the maximum intensity (typically: 10 to 30 mA for a light-emitting diode of low power and of the order of 350 to 1000 mA for a high-power LED) acceptable by the diode electroluminescent and therefore to interpose a current limitation. An energy efficient method is to use a current regulation circuit based on principles similar to those used in switching power supplies. Block 51 implements linear switching control. It would be possible to dispense with block 51 if the voltages at the terminals of the rechargeable energy source 4 and at the terminals of the light source 101 were perfectly equal. FIG. 9 illustrates said part of the economic embodiment of the invention as represented in FIG. 7, in the reception configuration 1 ", that is to say when the light source 101 electrically supplies the Rechargeable energy source 4. Arrows 60 symbolize light receiving by the light emitting diode The light source 101 is connected to the rechargeable power source 4 via a voltage conversion block 61.

The voltage conversion block 61 allows the voltage across the light source 101 to be greater than or equal to the voltage across the rechargeable power source 4. An example of a voltage conversion block 61 is illustrated in detail at FIG. FIG. 10. This is a type "boost" voltage converter assembly, for example making it possible to raise the voltage of the light-emitting diode 3 from 2.3 V to 4 V. The voltage conversion block 61 comprises: a switching regulator circuit 62 configured as an elevator, of the LT1937 type sold by the company Linear Technology (this is an example, which may change as a function of advanced technologies); a Schottky diode 63; a measuring resistor R1; an inductor such as a coil 64. The mounting is a voltage booster operating on the basis of switching regulator technology. FIG. 11 illustrates an advantageous variant of the portion of the economic embodiment of luminous signaling pad according to the invention as illustrated in FIG. 7.

The signal pad 80 then comprises in particular: measuring means 91 of a light intensity received by the light-emitting diode, when the light-signaling pad is in reception configuration; control means 92 for controlling switching of the luminous signaling pad alternately in the transmission configuration and in the reception configuration, for example periodically with a ratio equal to ten between the duration during which the luminous signaling pad is in the transmit configuration and the length of time it is in the receive configuration; and the control means 93 of the rechargeable energy source 4 as a function of the light intensity measured by the measuring means 91, in the emission configuration. The control means 93 of the rechargeable energy source may comprise a microcontroller, an electronic circuit for interfacing and controlling the measuring means 91, and an electronic circuit for supplying the rechargeable energy source 4. control means 92 for controlling a switching of the light signaling pad may be confused with the control means 93 of the rechargeable energy source. Two control stages can be provided: - an upper stage to pass a first time in the transmission configuration; a lower stage comprising the control means 92 for controlling a switching of the light signaling pad, which occurs once the upper stage has commanded to go into the transmission configuration. It is thus possible to adapt the light intensity emitted by the light source 101 to a light intensity received by this light source. Thus, when the light signaling pad is in operation, the light emission is nevertheless periodic, for example in a period of less than ten seconds. For example, a flashing of the light source 101 may be implemented, which has the additional advantage of attracting more attention to the luminous signaling pad 80.

The measurement of a light intensity received by the light-emitting diode may implement a measurement of the emitted current when it is reverse-biased. It is also possible to envisage other means for measuring a light intensity received by the light-emitting diode, for example implementing a measurement duration of discharge of a light-emitting diode assimilated to a capacitance. Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention. In particular all the features, shapes, variants and embodiments described above are combinable with each other in various combinations to the extent that they are not incompatible or exclusive of each other.

Claims (8)

REVENDICATIONS1. A light-signaling terminal (80) comprising a support (100), on which a light source (101) is mounted which provides a directional luminous flux directed along a predetermined optical axis (102), characterized in that it further comprises a refractive optics (104) forming with the support (100) a cavity around the light source (101), and arranged to redirect said luminous flux: 360 ° around the signaling pad and 10 so that this flux forms a luminous flux directional direction oriented according to a predetermined plane (105), which plane intersects said predetermined optical axis (102) and passes through the light signaling pad. 15 2. Light signaling plate (80) according to claim 1, characterized in that the refractive optic (104) is arranged to redirect said luminous flux according to a cone of opening angle of less than 30 °, said angle of aperture being measured in any plane orthogonal to said predetermined plane (105). 20 The light signaling pad (80) according to claim 1 or 2, characterized in that the predetermined optical axis (102) is orthogonal to said predetermined plane (105). 25 4. Light-signaling post (80) according to claim 1, 2 or 3, characterized in that the light source (101) comprises at least one light-emitting diode. 5. Light-signaling post (80) according to any one of claims 1 to 4, characterized in that the light source (101) comprises a light generating energy device and in that the light signaling pad (80) ) further comprises: a rechargeable power source (4), and switching means (5) between a transmission pattern (1 ') in which the light source (101) is electrically powered by the a rechargeable power source (4) and a receiving configuration (1 ") in which the light source (101) electrically supplies the rechargeable power source (4). Light-signaling terminal (80) according to claim 5, characterized in that in the receiving configuration (1 "), the voltage across the light source (101) is greater than or equal to the voltage across the terminals of the light source. rechargeable energy source (4). A light signaling terminal (80) according to claim 5 or 6, characterized by a voltage conversion circuit (61) connected in the reception configuration (1 ") between the light source (101) and the source of the light source. rechargeable energy (4). 8. Light signaling plate (80) according to any one of claims 5 to 7, characterized by: control means (92) for switching the light signaling pad (80), alternatively in the transmission configuration ( 1 ') and in the reception configuration (1 "), in the reception configuration (1"), measuring means (91) of a light intensity received by the light source (101); in the emission configuration (1 '), control means (93) of the rechargeable energy source (4) as a function of the light intensity measured by the measuring means (91) of a received intensity.