Light guide and associated electrical device

Abstract

To provide a light guide for an electrical device and an electrical device comprising such a light guide.SOLUTION: The light guide (110) comprises a body (120) having a substantially plane exit surface (112) and an entrance surface (122) configured to capture an incident light flux (F106) emitted by a light-emitting diode (106). The entrance surface (122) comprises a central face (124) astride a median plane (M120) and, on each side of the median plane (M120), a first lateral face (131) and a second lateral face (132), so that the incident light flux (F106) is divided into three distinct light fluxes. The body (120) further comprises external reflecting faces, each configured to reflect light fluxes associated with each lateral face toward the exit surface (112).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a light guide for an electrical device and to an electrical device comprising such a light guide. [Background technology]

[0002] We are concerned herein with electric or electronic devices that include an indicator light illuminated by one or more LEDs (an acronym for light-emitting diodes). The indicator light is located on the front side of the electric device to indicate the operational status of the electric device to a user. The LEDs are typically located on an electronic board, which is housed in an isolation housing of the electric device to ensure a minimum separation distance between the charged components of the electric device and the user.

[0003] The use of light guides made of electrically insulating materials to guide light emitted by LEDs to the front of an electrical device is known. The entrance face of the light guide is positioned opposite the LED, while the exit face of the light guide forms an indicator light. The exit face is generally perpendicular to the longitudinal axis of the light guide. The entrance face is positioned opposite the LED to capture the luminous flux emitted by the LED, while the exit face is at a minimum distance from the LED and, by extension, from the entrance face. For example, Tables 13 and 15 of the IEC 947-1:2019 standard define isolation classes, which correspond to the minimum distances that must be maintained between charged or potentially charged points and the user. The isolation distance depends, inter alia, on the desired isolation class and the voltage at which the electrical circuit breaker operates. Within the framework of this specification, two voltage ranges are primarily considered: the first range corresponds to voltages up to 690 V, and the second range corresponds to voltages strictly above 690 V. For voltages above 690V, isolation class 1 imposes an air distance of more than 7mm and a leakage line distance of more than 10mm. Isolation class 2 doubles those distances. For voltages below 690V, isolation class 2 requires an air distance of more than 10mm.

[0004] The inventors are particularly interested in indicator lights with an elongated shape, e.g., a horizontally elongated shape. The exit face therefore has a shape that is elongated along the width axis. While it is known to arrange multiple LEDs next to each other along the width axis to form such elongated indicator lights, such an arrangement leads to high consumption of electrical energy. To limit the electrical consumption, it is desired herein to limit the number of LEDs used to form the elongated indicator light as much as possible, preferably to a single LED.

[0005] The use of light guides is known, generally having a trapezoidal shape, with entrance and exit faces parallel to one another and shorter along the width axis than the exit face. In known approaches, the longer the light guide, the more uniform the output flux, particularly due to multiple reflections of light rays at the side walls of the light guide. For example, if the height of the light guide is greater than 2.5 times the width of the exit face, the output flux is considered to be substantially uniform. However, such light guides are relatively bulky and impractical.

[0006] It is known to add a dispersion material, for example in powder form, to the material of the light guide, but if the light guide has a height greater than a few millimeters, the intensity of the output beam is attenuated, which is undesirable, especially if the light source is limited to a single LED. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention more specifically addresses such a problem by proposing a light guide with an elongated exit face that has a relatively uniform output flux from only one LED with little light loss. [Means for solving the problem]

[0008] To this end, the present invention relates to a light guide for an electrical device, the light guide comprising a body, the body being made of an electrically insulating material, the material comprising a matrix having a refractive index comprised between 1.4 and 1.6 and a light transmission coefficient greater than 90% per millimeter, the body having a prismatic shape extending along a thickness axis, the body having, in projection in a transverse plane perpendicular to the thickness axis: an exit surface that is geometrically supported by a plane perpendicular to the height axis and has an elongated shape along a width axis, the width axis being perpendicular to the height axis, and the thickness axis, width axis, and height axis together form a Cartesian coordinate system; - a compartment comprising an entrance surface configured to capture an incident luminous flux emitted by the light emitting diode when the light emitting diode is positioned opposite the entrance surface, the entrance surface being aligned with the exit surface along a height axis such that the captured luminous flux primarily exits from the exit surface; - the body has a shape that is substantially symmetrical about a median plane of the light guide, the median plane being perpendicular to the width axis; - The entrance is a central surface, the central surface spanning the median plane, the central surface having two opposing lateral edges, the two opposing lateral edges being parallel to the thickness axis; a plurality of side surfaces on each side of the median plane, the side surfaces continuing from the lateral edges to the central plane on the same side of the median plane, the side surfaces including a first side surface and a second side surface, the first side surface being interposed between the central plane and the second side surface; - on each side of the median plane, in projection in the transverse plane, the central plane, the first side surface, and the second side surface form an angle between them configured such that an incident beam of light emitted by the light emitting diode and passing through the entrance surface is split into three separate beams of light by refraction as it passes through the entrance surface, and the three beams of light are: a central bundle, the central bundle corresponding to a portion of the input light bundle that is refracted as it passes through a corresponding portion of the central surface, the body being configured such that the central bundle expands to a central portion of the exit surface to form a central exit bundle; a first bundle, the first bundle corresponding to a portion of the incident bundle of light that is refracted when passing through the first side; and a second bundle, the second bundle corresponding to a portion of the incident bundle of light that is refracted when passing through the second side; - the body also comprises an outer reflective surface on each side of the median surface, the outer reflective surfaces being interposed between the exit surface and the entrance surface, each outer reflective surface being associated with a respective side and configured to reflect a portion of the luminous flux associated with the corresponding side towards the exit surface, the outer reflective surfaces being: a first outer reflective surface associated with the first side and configured to reflect the first bundle within the light guide such that the first bundle reflected thereby spreads toward a first portion of the exit surface to form a first exit bundle; and a second outer reflective surface associated with the second side and configured to reflect the second bundle within the light guide such that the reflected second bundle spreads toward a second portion of the exit surface to form a second exit bundle; the central output bundle, the first output bundle, and the second output bundle together form an output bundle from the exit face; At the outlet face, the second portion is interposed between the first portion and the central portion.

[0009] According to the invention, the light guide makes it possible to capture the luminous flux of the LED and distribute it to the user with a substantially uniform light intensity over an exit surface that is significantly longer than the LED. The use of a material with high transmittance, in other words good transparency, makes it possible to use only one LED alone, which results in energy savings.

[0010] According to advantageous but non-essential aspects of the invention, such a control unit may incorporate one or more of the following features, either individually or according to any technically permissible combination:

[0011] - The vector perpendicular to each outer reflecting surface, together with the axis perpendicular to the associated side, is given by the formula

number

[0012] The first side forms an angle with the central plane comprised between 110° and 130°, while the second side forms an angle with the first side comprised between 150° and 180°.

[0013] The body is made of a synthetic, high-temperature injectable polymer material, preferably polycarbonate or acrylic polymethyl methacrylate.

[0014] - the body has a front surface and a rear surface, the front surface and the rear surface being parallel to the transverse plane and oriented opposite each other, and the outlet surface connecting the front surface to the rear surface; On at least one side of the median plane, the body has a pair of recesses, the pair of recesses being provided on the anterior and posterior sides and being symmetrically disposed with respect to the transverse plane; Each recess has a contour that, when projected onto a transverse plane, defines three major sides, the three major sides being: a first side, the first side being bounded by a first bundle after reflection onto the first outer surface; a second side portion, the second side portion being bounded by a second bundle after reflection onto the second outer surface; and a third side, the third side being bounded by a central bundle between the central surface and the exit surface.

[0015] - the same pair of recesses provide between them a thinned portion of the body, while the thinned portion has a thickness, measured along the thickness axis, comprised between 20 and 50%, preferably comprised between 30 and 40%, more preferably substantially equal to 33% of the total thickness of the body.

[0016] - The recess is through and connects the front to the rear through the body.

[0017] A first side of each recess is polished to reflect the first bundle of light after reflection off the first outer reflective surface.

[0018] The present invention further relates to an electrical device, the electrical device comprising: - a housing made of insulating material and having a front surface; - a light emitting diode, the light emitting diode being received in a housing; a light guide as defined above, the entrance face of which is placed opposite the light emitting diode, while the exit face opens onto the front face of the housing.

[0019] Advantageously, The electrical device is a control unit for an electrical circuit breaker, and the front surface is configured to be oriented towards the user when the control unit is in a normal use configuration.

[0020] The present invention further relates to an electric circuit breaker comprising: a disconnection unit comprising at least one disconnection device and an actuator, the disconnection device being capable of being disconnected by the actuator; an electrical device as defined above, - the blocking unit provides a receptacle that opens to the front of the blocking unit; The control unit is received in the enclosure of the isolating unit so that the front face of the control unit is substantially aligned with the front face of the isolating unit.

[0021] The invention will be better understood and other advantages of the invention will appear more clearly in light of the following description of one embodiment of a light guide and circuit breaker according to the principles of the invention, given by way of example only and made with reference to enclosed stampings. [Brief explanation of the drawings]

[0022] [Figure 1] 1A and 1B are perspective and partially exploded perspective views of an electric circuit breaker according to the invention shown in two inserts a) and b), respectively, and further comprising a control unit according to the invention; [Figure 2] 2 is a perspective view of the control unit shown in FIG. 1, the control unit comprising a light guide according to a first embodiment of the invention; FIG. [Figure 3] FIG. 3 is a perspective view of the light guide and electronic board of the control unit shown in FIG. 2. [Figure 4] FIG. 3 is a side view of the light guide shown in FIG. 2, shown in two inserts a) and b). [Figure 5] 3A-3C are cross-sectional views of the light guide shown in FIG. 2 and light guides according to other embodiments of the present invention, shown at three inserts a), b), and c). [Figure 6] FIG. 10 is a perspective view of a light guide according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] An electric circuit breaker 10 is shown in FIG. 1. The electric circuit breaker 10, also referred to simply as circuit breaker 10, is herein a multi-pole circuit breaker, more specifically a three-pole circuit breaker. The number of poles is not limiting. In a known manner, a multi-pole electric circuit breaker comprises, for each pole, input and output power terminals that are connected or electrically isolated from each other by a circuit breaker interrupting device. The interrupting device comprises, for example, a separable movable contact, which is received in an interrupting chamber of the electric circuit breaker 10 and whose movement is controlled by an actuator. Thus, the interrupting device can be interrupted by the actuator. The interrupting chamber is embodied herein by three grids 12 visible on the top surface of the circuit breaker 10; other elements of the interrupting device are not shown.

[0024] The electrical circuit breaker 10 is intended for use in electrical installations, for example to control power to machine tools. In its normal use configuration, the electrical circuit breaker 10 is typically located in an electrical cabinet, with the electrical circuit breaker 10 having a front face 14 oriented toward a user standing in front of the electrical cabinet. The electrical cabinet is not shown.

[0025] The electrical circuit breaker 10 comprises an interrupting unit 16, which in particular comprises each of the interrupting chambers as well as an interrupting device and an associated actuator.

[0026] The electrical circuit breaker 10 advantageously comprises a faceplate 18 that can be removed from the rest of the interrupting unit 16. The faceplate 18 is made of an electrically insulating material and extends generally along a front plane P14, which defines part of the front face 14 of the electrical circuit breaker 10 and, by extension, the interrupting unit 16. The faceplate 18 therefore serves to protect the user from the interrupting unit 16. In FIG. 1a), the faceplate 18 is shown assembled to the interrupting unit 16, which corresponds to the normal use configuration of the circuit breaker 10. In FIG. 1b), the faceplate 18 is separated from the interrupting unit 16, which may be present, for example, during maintenance of the interrupting unit 16.

[0027] The electrical circuit breaker 10 further comprises a control unit 20. The control unit 20 is configured to analyze the state of the interrupting unit 16 and, depending on the result of the analysis, to interrupt the actuator, thereby separating the separable contacts.

[0028] The control unit 20 has a front surface 22, which has a flat overall shape and is geometrically supported by a front plane P22, which is perpendicular to a depth axis A22 of the control unit 20. When the control unit 20 is in its normal use configuration, the front panel 22 is oriented toward the user. Thus, the front surface 22 defines a front direction D22, which is parallel to the depth axis A22. The front direction D22 is represented by an arrow. Concepts of directions such as "front," "back," "up," and "down" are defined with respect to the elements depicted in the drawings, with the understanding that in practice the directions may differ.

[0029] The faceplate 18 includes a window 19 through which the front face 22 of the control unit 20 is visible. The window 19 is preferentially closed by a transparent flap, which is not shown.

[0030] The control unit 20 is reversibly assembled to the shut-off unit 16. In the example shown in Figures 1a) and 1b), the control unit 20 is shown in a configuration assembled to the shut-off unit 16. The control unit 20 is shown alone in Figure 2.

[0031] The isolating unit 16 provides a receptacle that opens onto a front face 14 of the isolating unit 16, and the control unit 20 is received such that a front face 22 of the control unit 20 is substantially aligned with the front face 14 of the isolating unit 16, as specifically shown in Figure 1a). The receptacle is not shown.

[0032] The control unit 20 is described below. The control unit 20 comprises a housing 30, which is made of an insulating material and forms a volume for receiving various components of the control unit 20, as discussed in detail below.

[0033] The housing 30 includes a front subassembly 100. In turn, the subassembly 100 resides within the control unit 20. The front subassembly 100 includes a central portion 102 that is generally flat and has a front side 102A and a rear side opposite the front side 102A.

[0034] The central portion 102 is configured herein to receive at least one human-machine interface element 104. A front side 102A of the central portion 102 is preferentially oriented along a forward direction D22. Human-machine interface is referred to by its acronym HMI. The human-machine interface element 104 may also be referred to simply as "HMI element" 104. In the illustrated example, the central portion 102 includes multiple HMI elements 104. The HMI elements 104 herein include multiple indicator lights 104A, a transparent portion 104B through which a screen can be observed, and multiple buttons 104C. This example is not limiting, and the type, number, and arrangement of the HMI elements 104 may be varied during the design of the front subassembly 100.

[0035] The front subassembly 100 is reversibly assembled to the rest of the control unit 20, more particularly to the housing 30, thereby allowing the front subassembly 100 to be replaced in the event of a malfunction. The central portion 102 thereby forms part of the front face 22 of the control unit 20.

[0036] The control unit 20 includes an electronic board 32 housed within a housing 30. In FIG. 3, the housing 30 is shown transparent, with the outline of the housing 30 indicated by a dotted line. The electronic board 32 includes a printed circuit and a number of electronic components, such as a microprocessor and one or more light-emitting diodes. Referring to FIG. 3, each of the indicator lights 104A is represented herein by a light-emitting diode 106, which is mounted on the electronic board 32 and generates a light beam that is guided by a respective light guide 108 to the surface 22 of the control unit 20. Each light guide 108 has an exit surface through which the light beam emitted by the corresponding diode 106 exits, thereby forming the corresponding indicator light 104A. The light-emitting diodes 106 are also referred to by the acronym LED. In the context of this specification, light-emitting diodes are simply referred to as "diodes." In the illustrated example, the electronic board 32 includes three diodes 106, each associated with a respective light guide 108.

[0037] Light guide 108 includes an elongated light guide 110 having an elongated exit face 112. Elongated light guide 110, also referred to herein as simply elongated light guide 110, is positioned between two other light guides 108.

[0038] The elongated guide 110 is described below.

[0039] The elongated light guide 110 comprises a body 120 made of an electrically insulating material, the material having a refractive index N comprised between 1.4 and 1.6. 120and a matrix having a light transmittance of greater than 90% per millimeter. Optionally, other components, such as fillers in powder form, are added to the material to aid in the manufacturing of body 120 and / or to modify the optical properties of the material of body 120, such that the material of body 120 is considered optically uniform and transparent.

[0040] The body 120 is advantageously made of a synthetic polymer material that can be injected at high temperatures. Preferred examples of such materials include polycarbonate, designated PC, or acrylic polymethyl methacrylate, designated PMMA. Polycarbonate, for example, has a refractive index of approximately 1.6, while PMMA has a refractive index of approximately 1.4. Air is considered to have a refractive index equal to 1. The body 120 is advantageously made by high-temperature injection in an injection mold.

[0041] In a variant (not shown), the body 120 is made of a mineral material, more particularly of mineral glass, whereby the light guide obtained is of good quality but is more expensive to manufacture.

[0042] The body 120 therefore comprises an outlet face 112. The outlet face 112 is preferably generally flat, and a normal to the outlet face 112 defines a height axis H120 of the body 120. The outlet face has a substantially rectangular shape herein, with the shorter side of the rectangle parallel to the thickness axis X120 of the body 120, while the longer side of the rectangle is parallel to the width axis Y120 of the body 120. In the example shown, the outlet face 112 has a first dimension, measured along the width axis Y120 of the body 120, equal to 14 mm, and a second dimension, measured along the thickness axis X120, equal to 3.2 mm.

[0043] In a variant (not shown), the outlet face 112 has an oblong shape, or even an elliptical shape, etc. The thickness axis X120, the width axis Y120 and the height axis H120 together form a Cartesian coordinate system.

[0044] The body 120 advantageously has a generally symmetrical shape with respect to a median plane M120 of the light guide, which is a plane perpendicular to the width axis Y120.

[0045] In this specification, the body 120 has the overall shape of a prism extending along a thickness axis X120, and the body 120 has a cross-section with a substantially constant profile when projected onto a transverse plane T120 perpendicular to the thickness axis X120.

[0046] The body 120 has a front face 114 and a rear face 115 which are parallel to the transverse plane T120 and oriented opposite each other, and the outlet face 112 connects the front face 114 to the rear face 115.

[0047] The cross section of the body 120 therefore comprises an outlet face 112 and an inlet face 122, the outlet face 112 being different from the inlet face and the inlet face 122 being aligned with the outlet face 112 along a height axis H120.

[0048] In a normal use configuration, one of the light-emitting diodes 106 of the electronic board 32 is positioned opposite the entrance face 122, as shown in FIG. 3 a) or FIG. 4 . Generally, light-emitting diodes of the type of diode 106 considered herein are configured to generate a substantially conical luminous flux F106 characterized by an apex angle. In the context of the present invention, the luminous flux F106 preferentially has an apex angle of approximately 120°. The entrance face 122 is configured to capture most of the luminous flux F106 emitted by the opposite light-emitting diode 106. The luminous flux F106 is therefore an incident flux that is captured by the entrance face 122 and then exits primarily through the exit face 112, as will be described in more detail below.

[0049] Generally, the luminous flux F106 is considered to be emitted by a central point 107A located on the top surface 107B of the light-emitting diode 106. The top surface 107B of the diode 106 is disposed perpendicular to the height axis H120, and the central point 107A is aligned with the height axis H120. For the purposes of this specification, the top surface 107B of the diode 106 is considered to be generally flat, with the understanding that in reality this may not be the case. Thus, the top surface 107B is geometrically supported by a top plane P107, which is perpendicular to the height axis H120.

[0050] Inlet face 122 comprises a plurality of surfaces, each of which is herein planar, that together form inlet face 122. Two consecutive surfaces of inlet face 122 form a non-zero angle therebetween and are arranged such that inlet face 122 is generally concave when viewed from the exterior of body 120.

[0051] Herein, the entrance face 122 has a central plane 124 that straddles the median plane M120. The central plane 124 has two opposing side edges 126 that are parallel to the thickness axis X120. On each side of the median plane M120, the entrance face 122 has a plurality of side surfaces 128 that extend from the side edges 126 on the same side of the median plane M120 to the central plane 124. Herein, the central plane 124 has a rectangular, or even substantially square, shape with each side having a length of about 2.5 mm. Herein, the top surface of the diode 106 is located about 3 mm from the central plane 124.

[0052] In this specification, the side surface 128 includes a first side surface 131 and a second side surface 132 on each side of the median plane M120, and the first side surface 131 is interposed between the central plane 124 and the second side surface 132.

[0053] On each side of the median plane M120, in projection in the transverse plane T120, the central plane 124, the first side surface 131, and the second side surface 132 form an angle between them configured such that an incident light beam F106 emitted by the diode 106 and passing through the entrance face 122 is split by refraction as it passes through the entrance face 122 into three light beams, the three light beams being: a central bundle F124, which corresponds to a portion of the input light beam F106 that is refracted as it passes through a corresponding portion of the central surface 124, the body 120 being configured such that the central bundle F124 expands towards a central portion of the exit surface 112 to form a central output bundle F140; a first bundle F131, which corresponds to the portion of the incident bundle F106 that is refracted when passing through the first side surface 131; and a second bundle F132, which corresponds to the portion of the incident bundle F106 that is refracted when passing through the second side surface 132;

[0054] The central bundle F124, the first bundle F131 and the second bundle F132 are schematically embodied in FIG. 4b) by a number of optical paths shown by chained dotted lines.

[0055] Due to the concavity of the entrance face 122, the incident light beam F106 is considered continuous before passing through the entrance face 122, whereas after passing through the entrance face 122, the central beam F124 and the first beam F131 diverge relative to each other, while the first beam F131 and the second beam F132 diverge relative to each other. "Two diverging beams" means that the respective optical paths of the two beams tend to diverge from each other.

[0056] The first side surface 131 forms with the central plane 124 a first angle α1 comprised between 110° and 130°, preferably between 115° and 125°. In the example shown, the first angle α1 is equal to 120°. Herein, the first side surface 131 has a length, in projection on the transverse plane T120, substantially equal to 1.1 mm.

[0057] The second side 132 forms with the first side 131 a second angle α2 comprised between 150° and 180°, preferably between 160° and 170°. In the example shown, the second angle α2 is equal to 164°. Herein, the second side 132 has a length, projected onto the transverse plane T120, substantially equal to 1.3 mm. It will be understood that the overall shape of the entrance face may be adjusted depending, inter alia, on the size of the diodes 106, the distance between the diodes 106, etc.

[0058] The body 120 also comprises an outer reflective surface on each side of the median plane M120, the outer reflective surfaces being interposed between the exit face 112 and the entrance face 122, each outer surface being associated with a respective side and configured to reflect a portion of the luminous flux associated with the corresponding side towards the exit face. a first external reflective surface 141, which is associated with the first side surface 131 and is configured to reflect the first bundle F131 within the light guide 110, so that the first bundle F131 reflected thereby spreads essentially over a first portion of the exit surface to form a first exit bundle F141; a second outer reflective surface 142, which is associated with the second side surface 132 and is configured to reflect the second bundle F132 inside the light guide 110, so that the first bundle F132 reflected thereby essentially spreads out towards the second portion of the exit face 112 to form the second exit bundle F142.

[0059] The central output beam F140, the first output beam F141, and the second output beam F142 together form the output beam F112 at the exit face 112.

[0060] At the exit face 112, the second portion is interposed between the first portion and the central portion, so that the flux F112 leaving the exit face 112 is substantially uniform, as shown diagrammatically in Figure 4a) In practice, it is advantageous for the central exit flux F140, the first exit flux F141, and the second exit flux F142 to overlap so as to enhance the apparent uniformity of the exit flux F112.

[0061] Advantageously, the outlet face 112 has a roughness Ra of about 1.6 μm to improve the impression of uniformity of the emission flux F112 leaving the outlet face 112. Here, the body 120 is manufactured by high-temperature injection, whereby each surface of the body 120 has a surface condition, more specifically, a roughness, substantially identical to that of the surface condition of the mold. The roughness of the surface of the mold is generally evaluated according to the scale "VDI 3400," which is the German name "Verein Deutscher Ingenieure," i.e., the acronym for the Association of German Engineers, and which links the non-uniform Charmilles index and the roughness Ra in μm to the surface of the mold. Thus, the outlet face 112 has a surface condition corresponding to a Charmilles index of 24.

[0062] Advantageously, the inlet face 122 has a so-called "mirror-polished" or "glass-polished" surface. The polished surfaces of plastic parts are usually rated according to the "SPI" scale, which is an acronym for "Society of the Plastics Industry", now renamed "Plastics Industry Association". Within the framework of this specification, a surface with a mirror-polished surface state has a surface state SPI of level "A2", which corresponds to a roughness Ra comprised between 0.012 and 0.025 μm.

[0063] Preferably, the first outer reflecting surface 141 is arranged so as to reflect all of the first flux F131, and similarly, the second outer reflecting surface 142 is advantageously arranged so as to reflect all of the second flux F132.

[0064] Generally, the limiting angle Θ of total reflection during reflection at the interface between the material of the body 120 and air lim The Snell-Descartes law can be used to calculate the limit angle, which is expressed as:

number

[0065] In addition to this example, the refractive index of air, N air is taken to be equal to 1, and the vector perpendicular to the first outer reflective surface 141, together with the vector perpendicular to the first associated side surface 131, is given by the formula

number

[0066] Similarly, the second outer reflective surface 142 is positioned such that the second flux F132 is entirely reflected. Thus, the vector perpendicular to the second outer reflective surface 142, together with the vector perpendicular to the associated second side surface 132, is expressed by the above equation:

number

[0067] As shown in the example, the refractive index N 120 When is equal to 1.4, the limiting angle Θ lim is approximately 45°, while the refractive index N 120 When is equal to 1.6, the limiting angle Θ limis about 38° Preferably, in a projection in a cross section, at any point on each side surface 128, an axis perpendicular to the side surface 128 passes through the center point 107A and intersects with the upper plane P107 of the diode 106. Due to such an arrangement, the first bundle F131 and the second bundle F132 all form non-zero angles with the axis perpendicular to the first side surface 131 and the axis perpendicular to the second side surface 132, respectively, so that the first bundle F131 and the second bundle F132 are inclined at a limit angle Θ to the corresponding outer reflecting surface 141 or 142. lim It is reflected at a smaller angle of incidence.

[0068] The body 120 has recesses 150 cut out in the front face 114 and the rear face 115 and arranged symmetrically with respect to the transverse plane T120. The recesses 150 are therefore associated in pairs, in other words arranged in pairs, each pair being located on one side of the median plane M120. In the example shown, the body 120 comprises two pairs of recesses 150, i.e., four recesses 150 in total.

[0069] The recesses 150 make it possible to limit the occurrence of sink marks and / or bubbles during the cooling of the light guide 110 manufactured by high-temperature extrusion, in other words, the recesses contribute to improving the optical quality of the light guide, in particular the uniformity of the light intensity at the exit face 112.

[0070] As detailed above, the particular shape of entrance face 122 means that light beam F106 is split into three branch beams F124, F131, and F132. Reflection at outer faces 141 and 142 means that certain areas inside body 120, known as "dead zones," are not traversed by most light rays. Recess 150 is therefore positioned in the dead zones to limit the loss of light intensity in exit beam F140.

[0071] Each recess 150 has a contour that, when projected onto the transverse plane T120, defines three major sides. The three major sides form a triangle, a first side 151, the first side 151 being bounded by the first bundle F131 after reflection onto the first outer surface 141; a second side 152, the second side 152 being bounded by the second bundle F132 after reflection at the second outer surface 142; a third side 153, which is delimited by a central bundle F124 between the central face 124 and the outlet face 112;

[0072] Advantageously, the first side 151 of each recess 150 is polished to reflect the first flux F131 after reflection from the first outer reflective surface 141, as shown in Figure 4b), in other words has a "mirror-polished" surface. Preferably, the first side 151, the second side 152, and the third side 153 are each polished. Preferably, the entire outer shape of each recess 150 is polished.

[0073] The recesses 150 are preferably partial, i.e., the recesses 150 of the same pair provide between them a thinned portion 152 of the body 120, which is positioned across the cross-section T120, as shown in FIG. 5a). The thinned portion 152 thus forms the bottom of the corresponding pair of recesses 150. The thinned portion 152 has a thickness, measured along the thickness axis, of between 20 and 50% of the total thickness of the body, preferably between 30 and 40%, and more preferably substantially equal to 33%. This allows for an improvement in the optical quality of the light guide 110 while limiting losses in the light intensity of the output beam F140.

[0074] In a variant, as shown in Figure 5b), the recess 150 is through and connects the front face 114 to the rear face 115 through the body 120. The body 120 then does not comprise any thinned portions such as the thinned portions 152 mentioned above.

[0075] According to another variant, as shown in FIG. 5c), the body 120 does not comprise any recesses such as the recess 150 mentioned above.

[0076] In the example shown, the body 120 includes a mounting member 160, which is provided to facilitate assembly of the light guide 110 to the front subassembly 100 and includes herein a protrusion 161 and a recess 162, which are provided on the front surface 114 and the rear surface 115, respectively.

[0077] In a variant, as shown in FIG. 6, the front face 114 or the rear face 115 does not include any protrusions or recesses such as the protrusions 161 or recesses 162 described above.

[0078] In the example shown, the exit face 112 is substantially flat. In a variant (not shown), the exit face is curved, for example convex.

[0079] In the example shown, the control unit 20 of the electrical circuit breaker 10 is one example of an electrical device that uses the elongated light guide 110. Of course, the principles of the present invention may be transferred to other types of electrical devices, with the elongated light guide 110 being particularly suited to applications requiring both low energy consumption and / or minimal separation distances between charged components and the user.

[0080] The above-described embodiments and variations may be combined with each other to produce new embodiments of the present invention. [Explanation of symbols]

[0081] 10 Electrical Circuit Breaker 16 Breaking unit 20 Electrical devices, control units 22 Front 30 Case 106 Light-emitting diode 110 Light Guide 112 Exit surface 114 Front 115 Rear 120 body 122 Entrance 124 Center plane 128 Side 131 First Aspect 132 Second Aspect 141 first outer reflective surface 142 Second outer reflective surface 150 recess 151 First Side 152 Second Side 152 Thin-walled section 153 Third Side F106 Incident luminous flux F112 output bundle F124 Central bundle F131 First Bundle F132 Second Bundle F140 center output flux F141 First exit beam F142 Second exit beam M120 Median plane T120 cross section X120 Thickness axis H120 Height axis Y120 width axis

Claims

1. A light guide (110) for an electrical device (20), said light guide (110) comprising a body (120) made of an electrically insulating material, said material comprising a matrix having a refractive index comprised between 1.4 and 1.6 and a light transmission coefficient greater than 90% per millimeter, said body (120) having a prismatic shape extending along a thickness axis (X120), said body (120) having, in projection in a transverse plane (T120) perpendicular to said thickness axis (X120), an outlet surface (112), said outlet surface (112) being geometrically supported by a plane perpendicular to a height axis (H120) and having an elongated shape along a width axis (Y120), said width axis (Y120) being perpendicular to said height axis (H120), said thickness axis (X120), said width axis (Y120) and said height axis (H120) together forming a Cartesian coordinate system; a compartment with an entrance face (122) configured to capture an incident luminous flux (F106) emitted by a light-emitting diode (106) when said light-emitting diode (106) is positioned opposite said entrance face (122), said entrance face (122) being aligned with said exit face (112) along said height axis (H120) such that said captured luminous flux (F106) mainly exits from said exit face (112), - said body (120) has a shape symmetrical with respect to a median plane (M120) of said light guide (110), said median plane (M120) being perpendicular to said width axis (Y120); said inlet face (122) a central surface (124) that straddles the median plane (M120) and has two opposing lateral edges (126), the two opposing lateral edges (126) being parallel to the thickness axis (X120); a plurality of lateral surfaces (128) on each side of said median plane (M120), said lateral surfaces (128) continuing from said lateral edge (126) to said central plane (124) on the same side of said median plane (M120), said lateral surfaces (128) including a first lateral surface (131) and a second lateral surface (132), said first lateral surface (131) being interposed between said central plane (124) and said second lateral surface (132); - on each side of said median plane (M120), in projection in said transverse plane (T120), said central plane (124), said first side face (131) and said second side face (132) form between them angles (α1, α2) configured such that said incident light beam (F106) emitted by said light emitting diode (106) and passing through said entrance face (122) is split into three separate light beams by refraction when passing through said entrance face (122), said three light beams being: a central bundle (F124), which corresponds to a portion of the input light beam (F106) that is refracted as it passes through a corresponding portion of the central surface (124), and the body (120) is configured such that the central bundle (F124) expands into a central portion of the exit surface (112) to form a central exit bundle (F140); a first bundle (F131), which corresponds to a portion of the incident bundle (F106) that is refracted when passing through the first side surface (131); a second bundle (F132), which corresponds to a portion of the incident bundle (F106) that is refracted when passing through the second side surface (132), said body (120) also comprises, on each side of said median face (M120), an external reflective surface interposed between said exit face (112) and said entrance face (122), each external surface being associated with a respective side face (128) and configured to reflect towards said exit face (112) the portion of said luminous flux associated with said corresponding side face (128), said external reflective surfaces being a first outer reflective surface (141), which is associated with the first side surface (131) and is configured to reflect the first bundle (F131) within the light guide (110), so that the first bundle reflected thereby spreads towards a first portion of the exit face (112) to form a first exit bundle (F141); a second outer reflective surface (142) associated with the second side surface (132) and configured to reflect the second bundle (F132) inside the light guide (110) so that the first bundle reflected thereby spreads towards a second portion of the exit face (112) to form a second exit bundle (F142); said central exit bundle (F140), said first exit bundle (F141) and said second exit bundle (F142) together form an exit bundle (F112) of said exit face (112), - at said outlet face (112), said second portion is interposed between said first portion and said central portion; A light guide (110).

2. The vector perpendicular to each outer reflecting surface (141, 142), together with the axis perpendicular to the associated side surface (128), is expressed by the formula [Equation 1] The critical angle of reflection, Θ, is defined by ｌｉｍ Forming a larger angle (β1, β2), Here, N １２０ The light guide (110) of claim 1, wherein is the refractive index of the material of the body (120) of the light guide (110).

3. - said first side surface (131) forms with said central surface (124) an angle comprised between 110° and 130°; A light guide (110) according to claim 1 or 2, wherein said second side (132) forms with said first side (131) an angle comprised between 150° and 180°.

4. A light guide (110) according to claim 1 or 2, wherein said body (120) is made of a synthetic, high-temperature injectable polymer material.

5. A light guide (110) according to claim 4, wherein said body (120) is made of polycarbonate or acrylic polymethyl methacrylate.

6. - said body (120) has a front face (114) and a rear face (115), said front face (114) and said rear face (115) being parallel to said transverse plane (T120) and oriented opposite each other, said outlet face (112) connecting said front face (114) to said rear face (115); - on at least one side of said median plane (M120), said body (120) has a pair of recesses (150), said pair of recesses (150) being provided on said front side (114) and said rear side (115) and being arranged symmetrically with respect to said transverse plane (T120); each recess (150) has, in projection on said transverse plane (T120), a profile defining three main sides, said three main sides being: a first side (151), said first side (151) being bounded by said first bundle (F131) after reflection onto said first outer surface (141); a second side (152), said second side (152) being bounded by said second bundle (F132) after reflection at said second outer surface (142); A light guide (110) according to claim 1 or 2, comprising a third side (153), the third side (153) being bounded by the central bundle (F124) between the central surface (124) and the exit surface (112).

7. - the recesses (150) of the same pair form between them a thinned portion (152) of the body (120); A light guide (110) according to claim 6, wherein said thinned portion (152) has a thickness, measured along said thickness axis (X120), comprised between 20 and 50% of the total thickness of said body (120).

8. A light guide (110) according to claim 7, wherein said thinned portion (152) has a thickness comprised between 30 and 40% of said total thickness of said body (120).

9. A light guide (110) according to claim 7, wherein said thinned portion (152) has a thickness equal to 33% of said total thickness of said body (120).

10. A light guide (110) according to claim 6, wherein said recess (150) extends through and connects said front face (114) to said rear face (115) through said body (120).

11. A light guide (110) according to claim 6, wherein the first side (151) of each recess (150) is polished so as to reflect the first bundle (F131) after reflection from the first outer surface (141).

12. An electrical device (20), comprising: a housing (30) made of insulating material and having a front face (22); a light-emitting diode (106) received in said housing (30); A light guide (110) according to claim 1 or 2, in which the exit face (112) opens onto the front face (22) of the housing, while the entrance face (122) is placed opposite the light-emitting diode (106); An electrical device (20) comprising:

13. The electrical device (20) of claim 12, wherein the electrical device is a control unit for an electrical circuit breaker (10), and the front surface (22) is configured to be oriented towards a user when the control unit is in a normal use configuration.

14. An electric circuit breaker (10), comprising: a shut-off unit (16) comprising at least one shut-off device and one actuator, said shut-off device being capable of being shut off by said actuator; - an electrical device according to claim 13, - said barrier unit (16) forms a container, said container opening onto the front face (14) of said barrier unit (16); an electric circuit breaker (10) in which the control unit (20) is received in the container of the interrupting unit, such that the front face (22) of the control unit (20) is aligned with the front face (14) of the interrupting unit (16).

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