Device for illuminating a target

Abstract

The invention relates to a device (1) for illuminating a target, the device comprising a support that defines a surface (21) for receiving a target to be illuminated and a light assembly (4) comprising a plurality of light sources, characterised in that the device (1) also comprises: • - a control unit (5) configured to turn at least one of the light sources on at a predetermined frequency and, simultaneously, keep at least one of the light sources switched off; and • - a mask.

Description

[0001] Target illumination device

[0002] The field of the invention is that of the design and manufacture of target lighting devices.

[0003] More specifically, the invention relates to a lighting device allowing a target to flicker.

[0004] To highlight a target, and in particular jewelry when it is on display, it is known to make it sparkle.

[0005] There are several techniques for this.

[0006] First, it is known to create jewelry stands equipped with lighting means.

[0007] For example, the patent document published under number US 6,433,483 describes a lighting device comprising a housing for receiving a piece of jewelry, and lighting means having a plurality of light sources.

[0008] The light sources are positioned in contact with the jewel, so that the light radiation they emit is directed directly towards the jewel and passes through it.

[0009] This device also includes control means for switching the light sources on or off so that the light radiation emitted by the light sources illuminates different points of the jewel randomly, or according to a precise pattern.

[0010] This results in a random propagation and refraction of light rays in the jewel, which causes, for a person looking at the jewel, a scintillating effect.

[0011] However, this type of device has a major drawback.

[0012] Indeed, the device, and more precisely the housing for receiving the jewel, must be designed according to the jewel to be highlighted. In other words, to be able to make all jewels or all types of jewels sparkle, the support is therefore designed according to each jewel.

[0013] This means that you need as many supports as there are pieces of jewelry to be lit.

[0014] Furthermore, such a system limits the natural effect of scintillation since the light sources are in contact with the jewel. The light sources are then visible to an observer who then knows where the light radiation causing the jewel to scintillate is coming from, to the detriment of the enhancement of the jewel or, at the very least, of its staging.

[0015] It is also known that the scintillation of a stone with several facets is obtained by the relative displacement between the light source(s) and the jewel. Indeed, this displacement allows the light radiation to impact the jewel from different angles, which causes, by reflection of the light radiation in the jewel, its scintillation.

[0016] For this purpose, different concepts have been developed.

[0017] Traditionally, jewelry lighting systems are fixed and it is the jewelry, mounted on a support, which is driven or set in motion to allow the reflection of light radiation emitted by fixed sources in order to create the sparkle of the jewelry.

[0018] For example, the patent document published under number US 2005 / 0028555 describes a jewelry support making it possible to make the jewelry mobile so that the external light radiation, even if it is fixed, impacts different facets of the jewelry in a punctual manner, thus causing it to sparkle.

[0019] However, although the system makes a piece of jewelry sparkle, it has a major drawback.

[0020] Indeed, moving the jewel requires either a mechanism to set it in motion, or to suspend the jewel from a frame. Therefore, the system can have significant dimensions that harm the enhancement of the jewel. Furthermore, setting the jewel in motion, when mechanized, requires energy and dedicated motorization means and can cause noise perceptible to the observer. On the other hand, when setting the jewel in motion is manual, its oscillation remains limited by physical phenomena and can only last a predefined time, generally quite short. Thus, when the jewel no longer oscillates, the scintillation disappears.

[0021] Another disadvantage of such a device for moving a piece of jewelry is that it requires the observer to change the angle of observation of the piece of jewelry to be highlighted. This is especially true since the perception of scintillation depends on the speed of this movement.

[0022] However, this system is useful when it is integrated into a piece of jewelry, for example a necklace, and it then allows the jewelry to move according to the movements of the person wearing it.

[0023] However, the glitter is limited by the fact that light radiation, usually natural light, is always present, making the glitter barely noticeable because too many light rays are impacting the jewelry simultaneously.

[0024] Furthermore, when it is to be displayed temporarily or when it is offered, the jewel may be received in a case allowing its transport. Such a case may include light sources emitting light radiation towards the jewel.

[0025] However, such cases limit the display of the jewel since the light sources are fixed, just like the jewel, which prevents flickering.

[0026] To remedy this, it is possible to control the switching on and off of the light sources in order to create a flicker by the alternating impact of the light radiation from each of the light sources on the jewel.

[0027] However, switching off the various light sources and switching them on temporarily creates a shadow on the jewel and / or around the case, this shadow being mobile depending on the positioning of the light sources when they are switched on. In other words, the alternating switching off and switching on of the light sources creates a moving shadow effect of the jewel and / or its case which is perceptible to an observer. This takes up part of the observer's attention and thus reduces the desired effect of highlighting the jewel.

[0028] The invention aims in particular to overcome the drawbacks of the prior art.

[0029] More specifically, the invention aims to propose a device for illuminating a target making it possible to make a fixed target sparkle in order to increase its highlighting compared to existing solutions, in particular without creating a moving light spot around the target or the target support.

[0030] The invention also aims to provide such a device allowing significant flickering of the target, and therefore its enhancement, while limiting energy consumption.

[0031] The invention further aims to provide such a device which is adaptable to all circumstances, or almost all.

[0032] The invention also aims to provide such a device which is transportable and which makes it possible to secure jewelry.

[0033] These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which relates to a device for illuminating a target, comprising: a support having a surface for receiving a target to be illuminated, and defining an area to be illuminated; a frame intended to be positioned, at least in part, above the support;a light group mounted in the frame, in elevation relative to the support, the light group comprising a plurality of light sources, characterized in that the device also comprises: a control unit coupled to each of the light sources, the control unit being configured to switch on at least one of the light sources at a determined frequency, and, simultaneously, to keep at least one of the light sources switched off, and a mask having, for each light source, an opening whose contour is a geometric transformation of the area to be illuminated of the receiving surface relative to a center of the light source with which the opening is associated.;

[0034] Such a device makes it possible to create a flickering effect of the illuminated target while limiting the illuminated area of ​​the support.

[0035] In fact, thanks to the mask and / or the focusing means, only the area to be illuminated is illuminated. This then results in an efficiency of the lighting device, since the luminous flux emitted by the light sources of the light group is entirely directed towards the area to be illuminated of the receiving surface. Thus, at equal lighting level, it is possible to limit the power of the light sources to allow the target to flicker.

[0036] Additionally, this allows the illumination to be limited to the receiving surface, which ensures the target is highlighted, especially when the receiving surface is limited around a target.

[0037] Finally, the mask and / or focusing means allow the light flux to be confined to a desired lighting zone, i.e. the area to be illuminated. This then contributes to highlighting the target since there is no moving light spot formed around the target.

[0038] This avoids disturbing the view of an observer, which would have the effect of limiting the desired effect of highlighting the target.

[0039] According to an advantageous aspect, the control unit is configured to apply to each light source a light intensity setpoint Ti so that at each instant, Tt = ,s =1 Ti, where N is the number of light sources switched on and Tt is a desired total lighting intensity.

[0040] Setting the control unit to apply the light intensity setpoint Ti to each light source allows the illumination of the receiving surface to be kept constant. This then results in an increase in the quality of the target highlighting by the flicker.

[0041] This is explained by the fact that since the total lighting intensity is constant and homogeneous over the area to be illuminated, regardless of the number of light sources switched on, the lighting device creates a magical effect for the observer who cannot distinguish the origin of the emission of the light radiation allowing the target to sparkle.

[0042] Furthermore, the light intensity setting applied to each light source makes it possible to increase the flickering of the target or to reduce it depending on the desired effect.

[0043] In other words, it is possible to nuance the glittering effect to further attract an observer's attention.

[0044] According to another advantageous aspect, the control unit is configured to turn on each light source according to a periodic pattern.

[0045] Using a periodic pattern for lighting light sources creates a repeating pattern, thereby promoting the illumination and sparkle desired by jewelers.

[0046] For example, using a periodic pattern can create a desired glitter path for highlighting a necklace, by circulating the glitter along the length of the necklace.

[0047] In this way, it is possible to emphasize a particular area of ​​the target or, on the contrary, to create a moving effect of the flickering which attracts the attention of an observer.

[0048] According to another advantageous aspect, the control unit is configured to turn on each light source in a random, or nearly random, pattern.

[0049] Using a random pattern allows the target to sparkle unpredictably when needed. For example, when the target is a gemstone, such as a diamond or a diamond- or pyramid-cut stone, using a random pattern can draw an observer's eye to different points on the diamond or stone, helping to highlight the target and enticing the observer to look at it from all angles.

[0050] According to another advantageous aspect, the light sources are arranged in a line.

[0051] The arrangement of light sources in a line allows for a compact lighting device.

[0052] In addition, the in-line arrangement of the light sources makes it easy to integrate the device into a box or carrying case, for example to display jewelry.

[0053] According to another advantageous aspect, the device integrates a heat sink.

[0054] The presence of the heat sink helps limit the heating of the light sources and more specifically the light unit. This can increase the lifespan of the lighting device, particularly when the device is integrated into a case.

[0055] In addition, the heat sink helps limit the heating of the light sources and therefore increases the duration of the target's illumination, i.e. the duration of the target's flickering. Furthermore, this also increases the light output while limiting the risk of the device overheating.

[0056] According to another advantageous aspect, the focusing means take the form of a collimator, each light source being associated with a collimator.

[0057] The presence of a collimator for each light source makes it possible to concentrate and direct, in a desired direction, the light radiation emitted by the light source.

[0058] Thus, with the collimation of the light radiation, it is possible to increase the efficiency of each light source and therefore reduce the energy required to produce the scintillation. In other words, thanks to the use of collimators, it is possible to reduce the power required by each of the light sources to allow the scintillation of the target.

[0059] This therefore promotes energy efficiency and the reduction of energy consumption of the lighting system.

[0060] According to another advantageous aspect, the mask integrates the collimators.

[0061] The integration of the collimator into the mask makes it possible to reduce the visibility of light sources for observers, and consequently their origin and location, contributing to a magical effect of the impression of natural flickering.

[0062] According to another advantageous aspect, each light source is associated with a lens.

[0063] Lenses allow the light flux to be concentrated in a chosen direction.

[0064] By coupling the lens with a mask, the light flux is directed only towards the area to be illuminated, which increases the highlighting of the target.

[0065] According to another advantageous aspect, the device comprises means for suspending the frame above the receiving surface.

[0066] This allows the light group to be moved away from the area to be illuminated, increasing the space around the target and allowing multiple viewing angles to admire the illuminated target. In addition, this can add a magical effect to the device since the light group, being moved away from the target to be illuminated, can be invisible to observers.

[0067] The invention also relates to a box comprising a casing and a cover for closing the casing, characterized in that the box incorporates a lighting device as previously described, the support being formed by the casing and the frame being integrated into the cover.

[0068] Such a box allows a target, for example a piece of jewelry, to be transported securely, while providing it with a display between two stages of transport. Indeed, the integration of the lighting device in the lid of the box allows the target to be highlighted when it is on the support, by lighting only the receiving surface without the lighting device being perceptible to the observer, or almost.

[0069] According to another advantageous aspect, the cover incorporates means of thermal conduction of the light group.

[0070] The thermal conduction means allow the heat generated by the light unit to be evacuated, which ensures that a user can handle the lighting device without the risk of burning themselves after using it.

[0071] In addition, this helps to limit the heating of the light unit and therefore the lifespan of the lighting device on the one hand and the duration of target illumination on the other.

[0072] According to another advantageous aspect, the mask came from material with a border of the cover.

[0073] Such an architecture makes it possible to further limit the size of the device and facilitate its integration into a box.

[0074] Other characteristics and advantages of the invention will appear more clearly on reading the following description of preferred embodiments of the invention, given as illustrative and non-limiting examples, and the appended drawings described below.

[0075] Figure 1 is a schematic perspective representation of a first embodiment of a lighting device according to the invention.

[0076] Figure 2 is a schematic perspective representation of a second embodiment of a lighting device according to the invention. Figure 3 is a schematic representation of a box incorporating a lighting device according to the invention.

[0077] Figure 4 is a schematic sectional representation of a detail of a particular embodiment of the lighting device according to the invention.

[0078] Figure 5 is a schematic sectional representation of a detail of another particular embodiment of the lighting device according to the invention.

[0079] Figure 6 is a schematic sectional representation of a detail of another particular embodiment of the lighting device according to the invention.

[0080] Figure 7 is a schematic sectional representation of a detail of a particular embodiment of the lighting device according to the invention.

[0081] Figure 8 is a graph representing the temporal evolution of a luminous intensity emitted by the luminous group of the lighting device according to the invention.

[0082] With reference to Figures 1 and 3, a device 1 for illuminating a target is now described.

[0083] According to the embodiments described below, the target is a jewel 1000. However, the target could be any object or even a person.

[0084] The lighting device 1 comprises a support 2 having a receiving surface 21 for the target to be illuminated. The receiving surface 21 defines an area to be illuminated 210 in which the target, i.e. the jewel 1000, is located.

[0085] The device 1 also comprises a frame 3 intended to be positioned, at least in part, above the support 2.

[0086] The lighting device 1 also comprises a light group 4 mounted in the frame 3, in elevation relative to the support 2. According to a first embodiment, illustrated by FIG. 1, the support 2 is the top of a display case and the frame 3 is an arch extending from the top, along one of the edges of the top. The frame 3 is thus integral with the top.

[0087] According to a second embodiment, illustrated by figure 2, the support 2 is the top of a display case and the frame 3 is suspended above the support 2. A bracket 31 is then coupled to the support 2 to keep the frame 3 elevated relative to the support 2, using suspension means 32. The suspension means 32 are for example cables connecting the bracket 31 to the frame 3. Furthermore, the cables can electrically supply the light group 4.

[0088] Alternatively, the frame 3 could be suspended from a structure separate from the support 2, for example a ceiling.

[0089] According to a third embodiment, illustrated by figure 3, the device is integrated into a box 10 comprising a box 11 and a cover 12 for closing the box 11. The frame 3 is then integrated into the cover 12.

[0090] During operation of the lighting device 1, the position of the frame 3 is fixed relative to the support 2 for the first and second embodiments.

[0091] For the third embodiment, the frame 3, being integrated into the cover 12, is orientable relative to the support. Thus, the position of the light group 4 relative to the area to be illuminated 210 can be adapted according to the shape and / or dimensions of the target.

[0092] The box 11 may have one or more handles allowing a user to grasp the box 10 in order to be able to transport it easily.

[0093] In the context of the third embodiment illustrated by Figure 3, that is to say when the lighting device 1 is integrated into a box 10, the support 2 of the device 1 is formed by the box 11 of the box 10, and the frame 3 of the lighting device 1. The latter is then integrated into the closing cover 12 of the box 11. More precisely, the receiving surface 21 of the support 2, and therefore the area to be illuminated 210, is formed by the bottom of the box 11.

[0094] The cover 12 has an internal face 121 intended to come against the box 11 in a position of closure of the box 11 by the cover 12.

[0095] The cover also has a border 122 surrounding the inner face 121.

[0096] The light group 4 is housed in the border 122.

[0097] The edge 122 has an edge 123 from which extends a rod 124 whose role is specified in the remainder of the description.

[0098] In Figure 5, it can be seen that the represented part of the light group 4 comprises a plurality of light sources 41.

[0099] The light sources 41 are, for example, light-emitting diodes (abbreviated “LEDs” in English).

[0100] In a manner common to each of the embodiments, and as illustrated by FIG. 7, the light group 4 also comprises: a heat sink 42; for each light source 41, focusing means or a lens 46; thermal conduction means, and an electronic card 45 on which the light sources are fixed.

[0101] The focusing means take the form of collimators 43, as illustrated schematically in Figure 4.

[0102] The collimators 43 make it possible to concentrate and guide the luminous flux, that is to say the luminous radiation, emitted by the light sources 41 only towards the area to be illuminated 210.

[0103] To do this, each of the collimators 43 comprises an internal face 431 allowing the collimation of the luminous flux by reflection. Furthermore, a collimator 43 makes it possible to use the entire luminous flux to direct it towards the area to be illuminated 210. This offers the possibility of using low-power light sources 41, which makes it possible to limit heating of the light group 4 and, consequently, to increase the lighting duration and the service life of the lighting device 1 by reducing the electrical consumption.

[0104] The various constituent elements of light group 4 are positioned as follows.

[0105] The electronic card 45 is secured to the heat sink 42 by a first face and to each of the collimators 43 or each of the lenses 46 by a second face carrying the light sources 41.

[0106] The thermal conduction means are in the form of a thermally conductive film 44 located between the electronic card 45 and the heat sink 42. The thermally conductive film is advantageously flexible to allow its malleability so that it deforms and takes the shape of a receptacle in which the light group 4 is received. Thus, this limits the presence of air bubbles which would have an insulating effect contrary to the desired heat dissipation.

[0107] Although Figure 7 illustrates the integration of the light group 4 in the cover 12 of the box 10, i.e. for the third embodiment, the described architecture of the light group 4 is adaptable to the first embodiment and to the second embodiment.

[0108] The lighting device 1 also comprises: a control unit 5, and a battery 6 for electrically powering the light sources 41.

[0109] Battery 6 provides autonomy for the electronic assembly of lighting device 1.

[0110] In an alternative embodiment, using the bracket 31, the power supply battery 6 can be replaced by a mains power supply. With reference to FIGS. 5 and 6, the device 1 comprises a mask 7 positioned in front of the light sources 41 in a direction of emission of the light flux by the light sources 41.

[0111] More precisely, the mask 7 has, for each light source 41, an opening 71 whose contour is a geometric transformation of the area to be illuminated 210 of the receiving surface 21 relative to a center of the light source with which the opening 71 is associated.

[0112] Referring to Figure 6, geometric transformation is a transformation that makes any point in space correspond to another point in a constant ratio with the first point relative to a fixed point.

[0113] In the present case, the fixed point is the center C of the light source 41 and the transformed point is located on a generator joining the contour of the receiving surface to the center of the source.

[0114] In other words, the opening 71 has the shape of a projection of the receiving surface at a predetermined height of a pyramid having as its base the receiving surface 21 and as its apex the center C of the light source 41.

[0115] Still with reference to Figure 6, the mask 7 thus makes it possible to block part of the luminous flux emitted by a light source 41 so that only the area to be illuminated 210 is reached by the luminous flux. In other words, the mask 7 forms a barrier to the rays of the luminous flux which are not directed into the area to be illuminated 210.

[0116] With reference to figure 7, the solution integrated in the cover 12 is that comprising a mask 7. In addition to the mask 7, the device 1 comprises a lens 46 making it possible to participate in refocusing the luminous flux.

[0117] In other words, the lens 46 makes it possible to reduce the quantity of luminous flux stopped by the mask so that the majority of the luminous flux, or even all of it in the best case, passes through the opening 71. Alternatively, the lens 46 could be replaced by a collimator 43.

[0118] As can be seen in Figure 5, not all of the openings 71 of the mask are identical depending on their position relative to the receiving surface 21.

[0119] Indeed, when the mask is inclined relative to the receiving surface 21, and in the case of a receiving surface 21 of rectangular shape, the more the opening 71 is centered relative to the receiving surface 21, the more it has a rectangular shape. On the contrary, the more it is off-centered relative to the receiving surface 21, the more the opening 71 has a trapezoidal shape.

[0120] On the other hand, when the mask extends parallel to the receiving surface 21, and therefore to the area to be illuminated 210, then all the openings 71 of the mask 7 have a rectangular shape when the area to be illuminated 210 is a rectangle.

[0121] According to another embodiment not illustrated, the light sources 41 form a matrix, that is to say they are distributed into a plurality of rows and columns.

[0122] When the lighting device 1 is integrated into a box 10, the mask 7 is defined for a precise orientation of the cover 12 relative to the box 11. This orientation can be maintained by dedicated mechanical means.

[0123] The mask 7 may have a small thickness, in which case it resembles a strip of material provided with the openings 71 or, on the contrary, have a significant thickness to partly define a guide for the light radiation of each light source 41.

[0124] In an alternative embodiment not illustrated by the figures, the openings 71 are mechanical. For example, the openings 71 are each formed by a diaphragm so that depending on the inclination of the cover 12 relative to the box 11, the shape of the openings 71 can be adapted so as to maintain the concentration of the luminous flux in the area to be illuminated 210. Means for ad hoc control of each of the diaphragms depending on the position of the cover 12 can then be provided.

[0125] The control unit 5 is coupled to each of the light sources 41. The control unit 5 is configured to turn on, according to a determined frequency, at least one of the light sources 41 and, simultaneously, to keep at least one of the light sources 41 off.

[0126] Of course, the light source 41 which is on is different from the light source 41 which is off.

[0127] The control unit 5 is configured to apply a light intensity setpoint Ti to each light source 41, so that at each instant, Tt = ,s =1 Ti, where N is the number of light sources 41 lit, and Tt is a desired total lighting intensity. More precisely, Tt is the total light intensity received by the area to be illuminated 210.

[0128] With reference to Figure 8, this means that the total desired lighting intensity is distributed according to the number N of light sources 41 lit at each moment.

[0129] In other words, the sum at each instant of the light intensity emitted by each light source 41 is equal to the total desired lighting intensity Tt which remains constant over time T.

[0130] In the example of Figure 8, the light intensity setpoints Ti of two light sources 41 are represented. The graph of Figure 8 corresponds to the intensity for each light source 41 (y-axis) as a function of time (x-axis).

[0131] A first light intensity setpoint Ti 1 of one of the light sources 41 and a second light intensity setpoint Ti2 of another of the light sources 41 are shown.

[0132] As time T progresses, the first light intensity setpoint Ti1 decreases, and the second light intensity setpoint Ti2 increases. We then see that for each instant on the time line T, the sum of the first light intensity setpoint Ti1 and the second light intensity setpoint Ti2 is constant and corresponds to the total desired lighting intensity Tt.

[0133] Figure 8 illustrates the light intensity instructions Ti of two light sources 41, however, the formula “Tt = J i Ti” est true P° ur un number N of light sources 41 greater than two.

[0134] As illustrated in Figure 8, the switching on and off of the light sources 41 is carried out progressively.

[0135] This makes it possible to maintain the desired total lighting intensity Tt constant and to avoid any risk of lighting defect since there is an overlap of the lighting from at least two light sources 41.

[0136] Furthermore, maintaining the desired total lighting intensity Tt constantly makes it possible to give the impression of natural flickering since there is no difference in illumination of the receiving surface 21 depending on the number of light sources 41 lit simultaneously. The natural effect is all the more enhanced since there is no variation in the light spot around the jewel 1000 depending on the origin of the light radiation. In other words, the illumination of the area to be lit 210 and therefore the light spot, when it is visible, is stable and does not give the impression of dancing on the receiving surface 21 during the periodic, pseudo-random or random change of the lit light sources 41. Furthermore, it is specified that the light intensity, expressed in cd, concerns the light source 41 while the illumination, expressed in lux, concerns the object lit by the light sources 41.

[0137] Furthermore, by gradually switching on and off the light sources 41, it is possible to make the flickering of the jewel 1000 more natural.

[0138] According to a first embodiment, the control unit 5 is configured to light each light source 41 according to a periodic pattern. According to a second embodiment, the control unit 5 is configured to light each light source 41 according to a random, or almost random, pattern.

[0139] The transition from a periodic pattern to a random pattern, or vice versa, can be achieved by ad hoc control means.

[0140] The control means may, for example, take the form of a computer application installed on a portable electronic device or a selector integrated into the lighting device 1.

[0141] According to a third embodiment, the control unit 5 is configured so that the desired total lighting intensity Tt is less than a constant limit value which makes it possible to illuminate the target to be illuminated without allowing a luminous zone to be perceived on the reception surface 21. In other words, when the target is illuminated, the reception surface 21 is not illuminated. Thus, in this embodiment, although this desired total lighting intensity Tt remains the sum of the light intensity setpoints Ti of the light sources 41 lit as previously, the desired total lighting intensity Tt can vary between a zero value and the constant limit lighting value to ensure a flickering effect.

[0142] With reference to Figures 1 to 3, the light sources 41 are arranged in a line. The line may be straight, as for the first and third embodiments (respectively illustrated by Figures 1 and 3), or have one or more radii of curvature as for the second embodiment (illustrated by Figure 2) in which the frame 3 is in the form of a ring.

[0143] According to a particular embodiment, the mask is integral with the frame 3. This benefits the compactness of the device 1, in particular when the light group is integrated into the cover 12 of the box 10.

[0144] According to the embodiment illustrated by figure 3, that is to say when the lighting device 1 is integrated into a box 10, the mask can be made in one piece with the edge of the cover 12. The mask 7 is for example machined in the cover 12. The mask 7 can provide housings for receiving the collimators 43.

[0145] According to an alternative embodiment not illustrated by the figures, the mask 7 integrates, for each light source 41, the collimator 43 which has an internal surface covered with black paint allowing the absorption of the deflecting light radiation emitted by the light source 41. By deflecting light radiation, it is meant the light radiation which is not directed towards the opening 71, but on the contrary directed towards the internal wall and the collimator 43.

[0146] In fact, when a fixed light source 41 is located above a jewel and emits light radiation directed towards it, each of the facets of the jewel reflects the light in one direction.

[0147] A nearby, fixed observer can then see some facets of the jewel light up when the light reflected by one of the facets is directed towards the observer's eye and reaches his eye.

[0148] If the observer, the jewel and the light source remain stationary, then the jewel does not sparkle.

[0149] On the other hand, when a relative displacement exists between the observer and the jewel, or between the jewel and the light source, then the rays reflected by each of the facets of the jewel are sent back in different directions, which causes a scintillating effect of the jewel when one of the facets intermittently reflects the radiation towards the eye of the observer.

[0150] The lighting device 1 which has just been described makes it possible to produce a scintillation of the target, here the jewel 1000, by relative movement between the light group 4 and the jewel 1000. In the case of highlighting a target being an object or a person, the rebound of the light radiation on different facets of the target causes the scintillation. The fact that a person wears clothing provided with rhinestones or sequins for example can increase the scintillation effect accordingly.

[0151] More precisely, the relative movement between the light group 4 and the target, here the jewel 1000, is obtained while the light group 4 is stationary relative to the jewel 1000. Indeed, to allow the movement of the light source, the light group 4 is provided with a plurality of light sources 41 as previously described.

[0152] The control of the light sources 41, that is to say their switching on and off, is carried out by the control unit 5.

[0153] More particularly, the control unit 5 controls the switching on of each light source 41, according to a predetermined, pseudo-random or random frequency.

[0154] The predetermined frequency corresponds to an ephemeral, even fleeting, ignition, that is to say over a very short period.

[0155] When at least one of the light sources is on, at least one of the light sources 41 is off.

[0156] Thus, by varying the lighting of each light source, the control unit allows a movement of displacement of the light radiation directed towards the jewel 1000, while the light group 4 remains stationary.

[0157] This then causes the jewel 1000 to sparkle since its different facets are illuminated discontinuously, randomly or in a predetermined manner.

[0158] Thus, for an observer who remains fixed in relation to the jewel, the different light rays reflected by the different facets of the jewel 1000 only reach the observer's eye discontinuously, which causes the scintillation effect.

[0159] The use of a periodic pattern by the control unit 5 to control the switching on of the light sources 41 makes it possible to produce a repetitive scintillation pattern of the jewel to highlight it in a particular way, for example by emphasizing one area more than another.

[0160] Thus, in the case of a piece of jewelry 1000 in the form of a necklace, as illustrated in FIG. 1, the scintillation can be produced along the piece of jewelry 1000 from a first end to a second end in a first direction and then in a second direction, i.e. in the form of a back and forth movement.

[0161] On the other hand, when the control unit 5 uses a random pattern, then the flickering of the jewel 1000 occurs in a disorderly manner, in a manner similar to a natural flickering of the jewel 1000. The random pattern will advantageously be defined so that it is not repeated during the same use.

Claims

CLAIMS 1. Device (1) for illuminating a target, comprising: a support (2) having a receiving surface (21) for a target to be illuminated, and defining an area to be illuminated (210); a frame (3) intended to be positioned, at least in part, above the support (2);a light group (4) mounted in the frame (3), in elevation relative to the support (2), the light group (4) comprising a plurality of light sources (41), characterized in that the device (1) also comprises: a control unit (5) coupled to each of the light sources (41), the control unit (5) being configured to switch on at least one of the light sources (41) at a determined frequency, and, simultaneously, to keep at least one of the light sources (41) off, and a mask (7) having, for each light source (41), an opening (71) whose contour is a geometric transformation of the area to be illuminated (210) of the receiving surface (21), relative to a center (C) of the light source (41) with which the opening (71) is associated.; 2. Device (1) according to any one of the preceding claims, characterized in that the control unit (5) is configured to apply to each light source (41) a light intensity setpoint Ti so that at each instant, Tt = ,s =1 Ti, where N is the number of light sources (41) switched on and Tt is a desired total lighting intensity.

3. Device (1) according to any one of the preceding claims, characterized in that the control unit (5) is configured to light each light source (41) according to a periodic pattern.

4. Device (1) according to any one of claims 1 or 2, characterized in that the control unit (5) is configured to light each light source (41) according to a random, or almost random, pattern.

5. Device (1) according to claim 1, characterized in that the light sources (41) are arranged in a line.

6. Device (1) according to any one of the preceding claims, characterized in that it incorporates a heat sink (42).

7. Device according to any one of claims 1 to 6, characterized in that each light source is associated with a lens (46).

8. Device according to any one of the preceding claims, characterized in that it comprises means (32) for suspending the frame (3) above the receiving surface (21).

9. Box (10) comprising a casing (11) and a cover (12) for closing the casing (11), characterized in that the box (10) incorporates a lighting device (1) according to any one of the preceding claims, the support (2) being formed by the casing (11) and the frame (3) being integrated into the cover (12).

10. Box (10) according to the preceding claim, characterized in that the cover (12) incorporates means of thermal conduction of the light group (4).

11. Box (10) according to one of claims 11 or 12, characterized in that the mask (7) is made in one piece with an edge (122) of the cover (12).

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