FR2664728A1 - Device for blanking out a light ray without mechanical shafts for panels with changeable messages - Google Patents

Abstract

The invention relates to a device making it possible to blank out one or more light rays, originating more particularly from the ends of optical fibres, thus allowing the formation of alphanumeric or graphics characters, by juxtaposition of several devices allowing or preventing the passage of the light. It consists of a tube (8) made of non-magnetic material in which a shutter (9), produced in solid or liquid ferro-magnetic material, circulates freely over one degree of freedom, and a minimum of one electromagnet (10) placed at the upper end of the tube. The lower part of the device is interposed between the light source and the visible part of the display system in such a way that the shutter, in upper or lower abutment of the device according to whether a DC current is or is not flowing in the electromagnet, allows or prevents the passage of the light. This invention is intended for the road and advertising field.

Description

 The present invention relates to a display device with optical fibers or the like, more particularly suitable for road or advertising signs but not exclusively. This device makes it possible to display alphanumeric or graphic information in monochrome or in color on panels, generally large, which can be modified remotely.

 Given the relatively high authorized speeds, especially on motorways, and possibly unfavorable climatic conditions such as sun in front or behind, fog, rain, it is essential that, for the safety of the user, the signaling informing them of events likely to be encountered on their route can be read in a very short time, without error or confusion, this in order to allow the user to have a reaction adapted to the situation.

 Many technologies for producing light-signaling panels are known. Thus the American patent 3,909,823, making it possible to display variable messages on a matrix panel remotely controlled and using a bundle of optical fibers as a light transmission organ is a first example. In this patent, the optical fibers, distributed so as to open into the visible face of the panel, make it possible to display letters or alphanumeric characters thanks to controlled lighting. The optical fibers can be associated, in a conventional manner, either in a group, or in isolation with shutters or occluders which controlled by an electromagnetic system which interrupt the path of the light beam towards the visible end of the panel. 'occultation can be constituted by a set of shutters or the like, controlled by electromagnets or by any other rotary system so that, according to the order, it is interposed between the light source and the fiber thus allowing interrupt or on the contrary leave the light path to the signaling free. Such mechanisms are known as, for example, that described by American patent 3,577,197. Another patent, 2,586,129, describes a different concealment method: this first uses a sliding pusher in a hollow core and provided at one end with a mask 90 "relative to itself and which comprises, on the other hand, a helical groove so that, with any movement of axial translation, is associated a movement of limited rotation of the core, therefore of the mask, thus allowing a concealment of a light ray which is in a plane perpendicular with respect to it. On the other hand, this patent also describes a system in which the pusher sliding in a core hollow and animated by an axial translational movement closes the light beam under the same conditions as described above, but without rotation of the mask.

However, the systems for occulting the optical fibers of a currently known sign have a certain number of drawbacks. The first is that, in general, these panels cannot use a high number of points, therefore of fibers, each alphanumeric character produced on the panel being formed on juxtaposed dies, and separated. This results in a limitation in the length of the message to be displayed. On the other hand, these systems, with their mechanisms for occulting optical fibers, do not have a reliability and operational safety allowing use of these panels in any medium with reduced failure rates. This drawback is especially encountered in the road environment where, despite the climatic conditions described above, there is an atmosphere polluted by exhaust gases and other dusts and where the supports the panels are subjected to vibrations due to aulx pasges desvehicles .. ~ ~
It is imperative that, in the context of using optical fiber as a light transmission member, the messages displayed can be read at long distances. This implies in particular a minimum height and spacing of the letters composing this message according to the minimum distance at which the message must be read, this in order to avoid the phenomena of halo or apparent superposition of the characters which can make the reading difficult and disturb the Strict standards have also been published on this subject and road signs must be subject to normal approval of Bridges and Roads. Another particular point, in the field of signaling based on optical fibers, is the particularly long response time of these occulting systems, having, for example, the effect of a very slow flashing or change of message. Other signaling techniques exist, including light-emitting diode systems which have a low luminosity which, moreover, decreases over time; but also laser systems or strobe lamps which have a very high manufacturing and maintenance cost.

 The present invention relates to a display and signaling device comprising a set of optical fibers, the ends of which open onto the visible faces of a panel. These fiber ends constitute a network of points allowing the materialization of writing characters or any other sign formed according to a graphics and a configuration determined by the lighting of these said points inside this network. Each optical fiber, or a limited number of optical fibers, is associated with an individual electro-magnetic occultation organ of the light ray traversing the fiber, individually controlled, and arranged upstream or downstream of the corresponding fiber, this device has, compared to current solutions, greatly improved reliability and operational safety at a reduced cost price. On the other hand, this device has a particularly optimized response time.

 For this purpose, the device considered is characterized in that the occultation member of each fiber or group of fibers consists of a tube plugged at both ends in which circulates an opaque pellet (or ferro-magnetic liquid). This can slide from one end to the other. The system is equipped, at a minimum, with a single coil electromagnet. This tube, by the characteristics mentioned above, has two extreme positions where the pellet (or the liquid) is the mask of occultaion.

 In a first embodiment of the invention, the tube is placed vertically with an electromagnet located at the upper end so that if no electric current flows in the coil, and by gravity effect, the tablet (or liquid) remains (or falls) naturally in the lower part of the tube. Similarly, when a current flows in the coil, the magnetic field thus created within the electromagnet attracts the pellet or the liquid. Depending on whether or not a current flows in the coil, we therefore obtain two free positions. It should be noted that if the current circulating in the coil is strong enough (in the form, for example, of a pulse with high amperage) and that the core of the electromagnet is provided for this purpose, a residual inductive field will maintain the attraction phenomenon despite the disappearance of the current which will be strong enough to keep the pellet (or the liquid) in the high position and that this effect can be canceled by a brief reversal of the current in the coil.

In another alternative embodiment, the tube is provided at its ends with two electromagnets controlled so that a current alone -
Thus it allows the tube to be positioned in any position.

 According to another embodiment of the tube is provided at one of its ends with an electromagnet and, at the other, with a permanent magnet so as to allow the system, as previously to be positioned in any which position, but to have only one command.

 Finally, according to various alternative embodiments, the tube may have a circular, oval, square or rectangular section cooperating with a pellet of suitable shape.

 It should however be noted that a circular shaped pellet remains the most efficient from the point of view of rotation inside the tube; the liquid presenting the ideal characteristics since without friction.

Other characteristics of a display and signaling device established in accordance with the invention will become more apparent from the following description of several exemplary embodiments, given by way of non-limiting example, with reference to the appended drawings in which:
Figure 1 is a schematic view of a fiber optic signaling panel, in which each fiber comprises an individual screening system according to the invention.

 Figure 2 is a large-scale view corresponding to Figure 1 of a fiber optic matrix according to the standards of road signs.

 FIG. 3 is a large-scale view of the first embodiment of an electromagnetic control system intended for the concealment of an optical fiber by patch according to the invention.

 FIG. 4 illustrates an alternative embodiment of an electromagnetic control system intended for the concealment of an optical fiber by patch according to the invention.

 FIG. 5 illustrates another alternative embodiment of an electromagnetic control system intended for the concealment of an optical fiber by patch according to the invention.

 FIG. 6 is a large-scale view of the first embodiment of an electromagnetic control system intended for the concealment of an optical fiber by ferro-magnetic liquid according to the invention.

 FIG. 7 illustrates an alternative embodiment of an electromagnetic control system intended for the concealment of an optical fiber by ferro-magnetic liquid according to the invention.

 FIG. 8 illustrates another alternative embodiment of an electromagnetic control system intended for the concealment of an optical fiber by ferro-magnetic liquid according to the invention.

 Figures 9 and 10 are diagrams intended to better explain the operation of the pellet shading system.

 Figures 11 and 12 are diagrams intended to better explain the operation of the pellet shading system.

 FIGS. 13 and 14 illustrate an example of a system obscuring two fiber ends simultaneously but which can be extended to any system obscuring a group of fibers or light ray.

 In FIG. 1, the reference (1) designates a display panel of luminous characters, or other, specialized in road signs and according to the standards in force, that is to say that, for a display on a motorway, the characters matrixed in points, materialized by 4 ends of fibers with their occultation systems, and distributed in minimum 5 columns (2) by 7 lines (3), have a height of 320mm. On the visible face of this panel, are distributed these matrices (4) in which the fibers, transmitting the light, make it possible to illuminate the points (5) on said face (6). The fibers of the entire network formed in the signaling panel (1) are supplied with light by external means such as halogen lamps (not shown), but themselves known in the art, these means being able to be associated with each fibers or to a group of fibers. Likewise each fiber can be associated individually or in group with an electromagnetic device making it possible, according to whether it is in use or out of circuit, to obscure the fiber, by preventing transmission, to through it, light or, on the contrary, to illuminate the corresponding point (5) in the visible face of the panel (1).

 FIG. 2 illustrates, on a larger scale, a matrix (4) of a traffic sign as seen in FIG. 1.

 FIG. 3 illustrates, on a large scale, an embodiment of a control system making it possible to provide at will and by a command optionally placed remotely occultation of the light or the free passage of the latter in each of the fibers ( 7) of the panel (1). This device essentially consists of a tube made of rigid, opaque and non-magnetic material (8) which can, for example, be made of plastic material, and in which a pellet (9 ) or partially ferro-magnetic material. This tube is arranged vertically with respect to the axis of translation of this pellet (9) which is attracted towards the upper end of the tube by an electromagnet (10) when a direct current flows in its coil (11) and which falls back into the lower end by gravity when a current does not flow in the coil (11) of the electromagnet (10). This tube can be of any size, section and shape, the pellet can have any shape provided that its section is adapted to the tube so as to maintain a degree of freedom in translation according to the invention, the power of the electromagnet to be adapted according to these criteria. References (12) and (13) respectively designate the supply terminals of the coil (11), these terminals being connected to a direct current source (not shown) when the pad is attracted.

 Figure 4 shows an alternative embodiment of the control system allowing it to be placed in any position thanks to the addition of a second electromagnet (15) placed at the other end of the tube (16), opposite the first electromagnet (14). This addition allows the system to be independent of the effect of gravity, due to the fact that only one of the two coils (18 and 19) is powered by a direct current at a time, the chip (17) is attracted to either of the electromagnets. Indeed, the wafer (17) is attracted towards one or the other of the electromagnets when their respective coil is supplied by the connection of the supply terminals (20, 20bis or 21, 21 bis) to a source of direct current.

FIG. 5 illustrates another variant embodiment of the control system offering the same advantages as the first variant described above. This device comprises a tube (22), a ferro-magnetic patch (23), an electromagnet (24) placed at one of the two ends of the tube (22), and a permanent magnet (25) placed at the other end of the tube (22). The wafer (23) will be attracted at rest by the permanent magnet (25) while it will be attracted by the electromagnet (24) when its coil (26) is connected to a direct current source (not shown) causing an induced magnetic field which will be greater than the magnetic field of the permanent magnet (25). This device allows the control system to be placed in any position. -
FIG. 6 illustrates, on a large scale, an embodiment of a control system making it possible to ensure at will and by a command possibly placed at a distance the occultation of the light or the free passage of this in each of the fibers (7) of the panel (1). This device essentially consists of a tube of rigid, opaque and non-magnetic material (27) which can, for example, be made of plastic, and in which a ferro-magnetic liquid (28) circulates freely or having the properties .This tube is arranged vertically with respect to the axis of translation of this liquid (28) which is attracted towards the upper end of the tube by an electromagnet (30) when a direct current flows in its coil ( 31) and which falls back into the lower end by gravity when a current does not flow in the coil (31) of the electromagnet (30). This tube can be of any size, section and shape according to the invention, the power of the electromagnet having to be adapted according to these criteria. References (32) and (33) respectively designate the supply terminals of the coil (31), these terminals being connected to a source of direct current (not shown) when the liquid is attracted.

 Figure 7 shows an alternative embodiment of the control system allowing it to be placed in any position by the addition of a second electromagnet (35) placed at the other end of the tube (36), opposite the first electromagnet (34). This addition allows the system to be independent of the effect of gravity, due to the fact that only one of the two coils (38 or 39) is supplied by a direct current at a time. Indeed, the liquid (43) is attracted towards one or the other of the electromagnets when their respective coil is supplied by the connection of the supply terminals (40, 40bis or 41, 41 bis) to a source of direct current.

 FIG. 8 illustrates another variant embodiment of the control system offering the same advantages as the first variant described above. This device comprises a tube (42), a ferro-magnetic liquid (43), an electromagnet (44) placed at one of the two ends of the tube (42), and a permanent magnet (45) placed at the other end of the tube (42). The liquid (43) will be attracted at rest by the permanent magnet (45) while it will be attracted by the electromagnet (44) when its coil (46) is connected to a direct current source (not shown). causing an induced magnetic field which will be greater than the magnetic field of the permanent magnet (45). This device allows the control system to be placed in any position.

 FIGS. 9 and 10 are diagrams intended to better explain the operating principle of the invention through an exemplary embodiment of a fiber optic display system by obscuring the ends thereof according to the first mode of production. This system is composed of an optical fiber end crimped in its end piece, a concealment device produced according to the first embodiment described in FIG. 3, and a focusing lens. The concealment device is interposed between the end of the optical fiber and the lens so as to interrupt or leave free the passage of light from the end of the optical fiber, depending respectively on whether the patch is in the low position, illustrated case. by FIG. 9, or high, case illustrated by FIG. 10, depending on whether the electromagnet is powered or not. In FIG. 9, the reference 51 corresponds to the electromagnet which is powered by its terminals (50), itself located at the upper end of a tube, opaque and made of non-magnetic material, of rectangular section (52) in which circulates freely and on a degree of freedom a round patch (55). It is made of composite material and surrounded by a ferro-magnetic material so as to be as light as possible and to minimize the dimension of the electromagnet (51). At the lower end of the tube is, on one of its sides and perpendicular thereto, a housing (57) characterized by a cylinder and intended to receive the end piece (53) of the end of the optical fiber (54 ) by simple stamping. Opposite the housing (57) and on the other side of the lower part of the tube (52) is the focusing lens (56) eccentric with respect to the tube (52) so as to be stamped on the display face of the panel and that it is the only visible.

The terminals (50) of the electromagnet (51) being connected to a source of interruptible direct current by a control which can be offset, when no current flows in the electromagnet, the system then being at state of rest, the patch (55) is located by gravity in the lower part of the tube and therefore obscures the end of the optical fiber. Similarly, in FIG. 10, when no current flows in the electromagnet, the system then being in the working state, the pellet (55) is located by electromagnetic effect in the upper part of the tube and let the light pass through.

 FIGS. 11 and 12 are diagrams intended to better explain another operating principle of the invention through the same example of embodiment of a fiber optic display system by occultation of the ends thereof according to another embodiment. This system is composed of an optical fiber end crimped in its end piece, a concealment device produced according to the embodiment described in FIG. 6, and a focusing lens. The concealment device is interposed between the tip of the optical fiber and the lens so as to interrupt or leave free the passage of light from the end of the optical fiber respectively depending on whether the ferro-magnetic liquid is in the low position, case illustrated by Figure 11 , or high, case illustrated in Figure 12, depending on whether the electromagnet is powered or not. In FIG. 11, the reference (59) corresponds to the electromagnet which is supplied by its terminals (58), itself located at the upper end of a tube, opaque and made of plastic, of section rectangular (60) in which a ferro-magnetic liquid (64) flows freely. At the lower end of the tube there is, on one of its sides and perpendicular to it, a housing (63) characterized by a cylinder and intended receiving the tip (61) from the end of the optical fiber (62) by simple stamping. Opposite the housing (63) and on the other side of the lower part of the tube (60) is the focusing lens (65) eccentric with respect to the tube (60) so as to be pressed on the face d display of the panel and that it is the only one visible.

The terminals (58) of the electromagnet (59) being connected to a source of interruptible direct current by a control which can be offset, when no current flows in the electromagnet, the system then being at in a state of rest, the liquid (64) is located by gravity in the lower part of the tube and therefore obscures the end of the optical fiber. Similarly, in FIG. 12, when no current flows in the electromagnet, the system then being in the working state, the liquid (64) is found by electromagnetic effect in the upper part of the tube and let the light pass through.

 FIGS. 13 and 14 are diagrams intended to better explain another operating principle of the invention through an exemplary embodiment of a fiber optic display system by obscuring the ends thereof according to the first mode of achievement. This system is composed of two ends of optical fibers certified in their ends, of a concealment device produced according to the embodiment described in FIG. 6 and improved, and of a focusing lens. The concealment device is interposed between the end of the optical fiber and the lens so as to interrupt or leave free the passage of the light coming from the end of the optical fiber respectively according to whether the patch is in the low position, illustrated case by figure- 13, or high, case illustrated by figure 14, and whether the electromagnet is powered or not. In figure 13, the reference (67) corresponds to the electromagnet, powered by its terminals (66), which is located at the upper end of an opaque tube, made of non-magnetic material and of rectangular section (68) in which circulates freely and on a degree of freedom a rectangular patch and whose sides are rounded ( 76). It is made of composite material, or other material, and surrounded by a ferro-magnetic material so as to be as light as possible and to minimize the dimension of the electromagnet (51). On the other hand, a hole (72) of diameter equal to that of the optical fiber section is machined in the middle of the patch so that, in the low position, it obscures the light ray coming from the end of the upper optical fiber. (71) and unlike, in the high position, the hole is located opposite this said radius and allows the passage of light. At one end of the tube are, on one of its sides and perpendicular to it, two housings (69 and 75) characterized by a block of non-magnetic material, of width identical to that of the tube and height corresponding to two superimposed lenses (77), in which are drilled two cylindrical holes intended to receive the end pieces (70 and 73) of the ends of the optical fibers (71 and 74) by simple stamping. Opposite the housings (69 and 75) and on the other side of the lower part of the tube (68) are the focusing lenses (77) eccentric with respect to the tube (68) so that they can be pressed on the display face of the panel and that they are the only ones visible. The terminals (66) of the electromagnet (67) being connected to a source of interruptible direct current by a command which can be offset, when no current does not circulate in the electromagnet, the system is then in the state of rest, the patch (76) is by gravity effect in the lower part of the tube and thus comes to obscure the light rays coming from the ends of the optical fibers . Similarly, in FIG. 14, when a current flows in the electromagnet, the system then being in the working state, the pellet (76) is by electromagnetic effect in the upper part of the tube and leaves free passage to light. References 78 and 79 respectively designate a profile and front view of the patch intended to obscure a group of two ends of optical fibers. In the front view, the reference 80 corresponds to the ferromagnetic surround, the reference 1 to the body of the patch and the reference 82 with hole made in the patch so that in the high position the light ray coming from the upper fiber. can pass through the patch. This example clearly shows that the invention applies to all configurations starting from the concealment of a single end to the concealment of several ends of optical fibers simultaneously.

 The device according to the invention is particularly intended for display and signaling in the road and advertising fields.

Claims (10)

 1.- Device for occulting light rays which can be placed at one end of an optical fiber (or group of optical fibers), one of which is facing a light source and the other leading to the visible face (6) of a luminous panel (1) intended for signaling and display, characterized by a tube (8) in which circulates freely a patch (9) made, or partly, of ferro-magnetic material and having a longitudinal dimension less than at least equal to the diameter of the radius to be obscured, the tube (9) being equipped at its upper end with an electromagnet (10) and plugged at its lower end so that when current, coming from a source of direct current and interruptible locally or remotely, circulates in the electromagnet (10), the magnetic field thus created attracts the pellet (9) in the upper end of the tube and, on the contrary , when there is no current flowing through the tablet (9), by gravity effect falls and remains in the lower end of the tube.  2. A device for occulting light rays according to claim 1, characterized in that if the attraction current of the pellet (9) flowing in the electromagnet (10) is in the form of a strong pulse. intensity and that the electromagnet (10) is adapted, the remanent magnetic field will maintain the pellet (9) in the upper stop of the tube (8), and that, to make it fall towards the lower stop it is necessary to apply to the electromagnet a reverse current in the same form as above but of intensity equal to the creation of an inverse magnetic field and proportional to the remanent magnetic field so as to neutralize it.  3.- device for occulting light rays according to claim 1, characterized in that the tube (16) is equipped with an electromagnet at each of its ends (14 and 15) so that, alternately controlled , the pellet (17) is attracted to one or the other of the ends of the tube (16).  4. A device for occulting light rays according to claim 1, characterized in that the tube (22) is equipped with an electromagnet (24) at one of the ends and with a permanent magnet (25) at the 'other end so that, when no current flows in the coil (26) of the electromagnet (24), the pellet (23) is attracted to the stop of the tube (22) where is l permanent magnet (25).  5. A device for occulting light rays according to claim 1, characterized in that the patch (9, 17, 23, 76 and 79) is composed of an opaque ferro-magnetic material but, in order to be lightened, may consist of a core (81) made of opaque and light material such as plastic or composite and a peripheral envelope (80) of ferro-magnetic material.  6. A device for occulting light rays according to claims 1, 2, 3 and 4 characterized in that the patch is replaced by an opaque ferro-magnetic liquid or having the characteristics (28, 43 and 63).  7. A device for occulting light rays according to claim 1, 2, 3 and 4 characterized in that the device can obscure one or more light rays thanks to machined holes (72 and 82) in the patch (76 and 79 ) and whose bore has, as a minimum diameter, the section of the light ray to be obscured and which may be from an optical fiber (71 and 74).  8. A device for occulting light rays according to any one of the claims, characterized in that it interfaces between the focusing lens or lenses (56, 64 and 77) and one or a group of ends of optical fibers (54 , 62, 71 and 74) opening into the visible face of the panel.  9.- Device for occulting light rays according to any claim characterized in that only the lenses (56, 64 and 77), stamped behind the front face of the panel (1), are only visible on the visible side of this face .  10.- Device for occulting light rays according to any claim characterized in that only the lenses (56, 64 and 77), only visible on the visible side of the front face of the panel (1), can be implanted in that -this in the form of continuous bands or in matrices (4) and of which each points (5), which can be composed of one or more lenses (7), can be switched on or off locally or remotely in order to form alpha characters - digital or graphics. The lenses (7) can be tinted with different colors and this uniformly or not on a point (5) composed of several lenses (7), and that, by association of lenses of different colors, the points (5) can appear multicolored.