A system for testing the properties of precious stones

Abstract

This relates to a system equipped with a lighting device specially adapted to enable the visual identification of the properties of precious stones. [Solution] The present invention relates to an apparatus for illuminating a gemstone, comprising a light projector having a main illumination module (14a) for generating illumination specially configured to reveal the properties of the gemstone, the main module comprising a circuit board (25) including a plurality of light sources (16) each emitting a light beam and light diffusing elements arranged opposite the plurality of light sources, the main module comprising a reflector (21) disposed between a support element and the light diffusing elements, the reflector comprising at least one cavity capable of reflecting at least a portion of the light beam toward the light diffusing elements, each cavity being formed by a bottom (17) and a peripheral wall (18a) extending from the bottom toward the light diffusing elements, the top of which is located at a first distance (E1) from the light diffusing elements.

Description

Technical Field

[0001] The present invention relates to a system for testing the properties of precious stones, and more particularly to a system comprising an illumination device specially adapted to enable visual identification of the properties of such stones.

Background Art

[0002] In the current state of the art, systems for testing the properties of precious stones such as diamonds are generally used to verify their authenticity or to classify or otherwise sort these precious stones. For this purpose, these systems generally use an illumination device comprising a fluorescent tube to visually test their internal or external properties such as color, purity, size or fluorescence.

[0003] However, one of the main drawbacks of such systems is that they are not sufficiently safe, as the fluorescent tubes used in these illumination devices contain substances harmful to both the environment and human health, such as mercury.

[0004] Furthermore, these fluorescent tubes are known to produce humming sounds, which is an acoustic nuisance that can disrupt the concentration of the operator responsible for identifying their properties. Additionally, these fluorescent tubes can cause flickering or flashing, which is difficult to perceive but can be a problem for operators who are sensitive to light, prone to headaches, dizziness, or have disorders such as epilepsy. Finally, the arrangement of these fluorescent tubes in these systems does not allow the properties of these precious stones to be clearly and repeatedly revealed.

[0005] In view of these situations, there is clearly a need to find a harmless alternative solution.

Summary of the Invention

[0006] One of the objectives of the present invention is to provide a solution for improving the accuracy of testing the properties of precious stones using a system for testing these properties, the system comprising an illumination device configured to produce accurate, dynamic, and adaptive illumination of these stones.

[0007] For this purpose, one aspect of the present invention relates to an apparatus for illuminating a gemstone, comprising a light projector having a main illumination module for generating illumination specially configured to reveal the properties of the gemstone, wherein the main module comprises a circuit board including a plurality of light sources, each emitting a light beam, and light diffusing elements positioned opposite the plurality of light sources, wherein the main module (14a) comprises a reflector positioned between the support element and the light diffusing elements, wherein the reflector comprises at least one cavity capable of reflecting at least a portion of the light beam toward the light diffusing elements, each cavity being formed by a bottom and a peripheral wall extending from the bottom toward the light diffusing elements, the respective tops of which are positioned at a first distance from the light diffusing elements.

[0008] In other embodiments, the reflector comprises two cavities capable of reflecting at least a portion of a light beam toward a light-diffusing element, each cavity formed by a bottom, a peripheral wall, and a partition wall separating it from the other cavity, the wall extending from the bottom toward the light-diffusing element, with the top of the peripheral wall positioned at a first distance from the light-diffusing element and the top of the partition wall at a second distance, the first distance being less than the second distance. The light source comprises an electroluminescent element. The light source has a color temperature adjustable in the range of 2,500K to 7,000K, preferably in the range of 5,700K to 6,300K. The device comprises a module for setting functions performed by the device, the module comprising an operating section for controlling these functions and a screen for displaying information regarding these functions. The functions relate to the illumination and temperature setting of the light source. The device comprises an articulated arm comprising a first part and a second part connected to each other at one of its two ends. The first and second parts each include at least one motor capable of controlling the horizontal and / or vertical movement of the projector relative to the gemstone. The apparatus includes peripheral modules positioned on the side of the projector and configured to attenuate light disturbances that may be caused by light sources outside the apparatus.

[0009] Another aspect of these aspects of the present invention relates to a system for testing the properties of a gemstone, comprising the above-described illumination device and support element, wherein the device is fixed to the support element and configured to produce illumination of a region of interest contained on a plate of the support element, the region of interest comprising the gemstone which may be handled by the user. [Brief explanation of the drawing]

[0010] The object, advantages, and features of the present invention will become apparent from the following detailed description of the invention, which is given by example and made with reference to the following accompanying drawings. [Figure 1] One embodiment of the present invention provides a system for testing the properties of a precious stone, comprising a lighting device suitable for such a stone and a plate on which such device is fixed. [Figure 2] This shows the light spectrum emitted by an illumination device according to the present invention, having a color temperature between 2,500K and 7,000K. [Figure 3] This is a schematic plan view of a main lighting module that generates lighting included in a projector of a lighting device according to the present invention, and is a schematic plan view comprising a plurality of light sources. [Figure 4] Figure 3 is a cross-sectional view of the main module AA that generates the lighting shown. [Modes for carrying out the invention]

[0011] Figure 1 shows a schematic of a system 1 for testing the properties of a gemstone 10, comprising a lighting device 2 specially adapted to highlight or distinguish one or more properties of the gemstone 10. Such a system 1 may be part of a user's work environment, which is preferably set up in a room within a building. In other words, the system 1 may be the sole light source in the room, or the room may have a more or less diffuse light source, such as sunlight.

[0012] It should be noted that these precious stones 10 include, but are not limited to, gemstones such as diamonds, sapphires, rubies, and emeralds. Furthermore, the properties of such precious stones 10, also called characteristics, include, but are not limited to, color, purity, size, and fluorescence.

[0013] The system 1 comprises a support element 7, such as a desk or workbench, formed by a plate 6, particularly a rectangular plate. Such a plate 6 has a region of interest 8 on all or part of its surface, which can be illuminated by an illumination device 2. This region of interest 8 comprises a support 9 on which a gemstone 10 having properties to be observed can be placed.

[0014] This plate 6 includes an area where the lighting device 2 is fixed to the support element 7.

[0015] Such a system 1 assists a user, also called an observer, in visually testing the properties of a gemstone 10 contained in a region of interest 8, and such testing may include an evaluation of these properties. In other words, the user performs such testing based on a visual perception of these properties of the gemstone 10. This visual perception can be defined as the result of how the user's brain interprets the information about these properties contained in the incident light radiation that is taken in by photoreceptors and enters the eye through the pupil to activate receptor cells located in the retina. The optic nerve then transmits the signals generated by these cells to the brain.

[0016] In this region of interest 8, the gemstone 10 can be handled by the user. In this system 1, such region of interest 8 may be either a space defined on the plate 6 on the support element 7 when the gemstone 10 is placed or rested on the support and thus occupies a portion of the surface of the plate 6, or a volume defined above the plate 6 in which the gemstone 10 is contained when the gemstone 10 is handled by the user.

[0017] Such areas of interest (8) may be specially illuminated according to the user's visual profile and / or at least one characteristic of the stone.

[0018] In this system 1, the lighting device 2 comprises a light projector 3, an articulated arm 12 having a first part and a second part 4a, 4b connected at one end of the two ends thereof, at least one electric motor, the electric motor located within the arm 12, and a module 5 for setting functions performed by the device, the module comprising an operating unit 15a for controlling these functions and a screen 15b for transmitting information regarding these functions.

[0019] In this device, the arm 12 is configured to connect / fix / attach the projector 3 to the support element 7 of the system 1 within the mounting / fixing area 24 defined on the plate 6.

[0020] This projector 3 has a cross-section whose axial or transverse cross-section is a polygonal shape respectively. Such a projector 3 has a front part, a rear part, and two side parts.

[0021] Such a projector 3 includes a protective housing, a main illumination module 14a, at least one auxiliary illumination module 14b, a connecting element 13 that connects the projector 3 to the arm 12 of the device 2, and a protective element 11 for protecting against the light emitted by the projector 3. This protective element 11 enables protecting the user's eyes from the light beam that can originate from the main illumination module 14a.

[0022] In this configuration, the protective element 11 is fixed to the front part of the projector 3, and the connecting element 13 is fixed to the rear part of the projector 3.

[0023] Such a connecting element is configured to be able to orient the projector 3 around at least three axes A, B, C with respect to the region of interest 8, particularly with respect to the gemstone 10 within the region of interest 8. The projector 3 is further movable vertically and / or horizontally with respect to the region of interest 8, particularly with respect to the gemstone 10 within the region of interest 8. For example, for vertical movement, the angle α formed between the first part 4a and the second part 4b of this arm 12 can be changed, and for horizontal movement, the angle β formed in the mounting region 24 where the arm 12 is attached to the plate 6 can be changed.

[0024] This protective housing includes a chamber in which the main illumination module 14a and the at least one auxiliary illumination module 14b are arranged.

[0025] The main illumination module 14a shown in FIGS. 3 and 4 can generate illumination that is specially configured to reveal the characteristics of the gemstone 10. It should be noted that this illumination corresponds to the light beam emitted by the main module 14a and received per unit surface area by the region of interest 8, particularly the gemstone 10. This illumination depends on the light intensity and the distance of the main module 14a from the region of interest 8, and thus the gemstone 10.

[0026] This main illumination module 14a includes a plurality of light sources 16 each configured to generate a light beam, a light diffusing element arranged opposite to the plurality of light sources 16, and a reflector 21 having one or more cavities capable of reflecting one of the light beams towards the light diffusing element, and the reflector 21 includes a bottom 17, peripheral walls 18a, 18b, 18c, and a partition wall 19.

[0027] More specifically, the main illumination module 14a includes a circuit board 25 on which the light sources 16 are arranged. This module further includes a heat sink 20 in contact with the circuit board 25. In particular, this heat sink enables the dissipation of the heat generated by the light sources 16.

[0028] In this context, the circuit board 25 is used to supply current to the light sources 16. In this example, the light sources 16 are electroluminescent elements such as electroluminescent diodes. These light sources have an adjustable color temperature of 2,500K to 7,000K, preferably 5,700K to 6,300K, and preferably 6,000K.

[0029] In this example, these light sources 16 are arranged in rows and columns on the circuit board 25 to form groups. In the examples of FIGS. 3 and 4, 24 light sources 16 are arranged in 2 rows and 12 columns to form two groups each consisting of 12 light sources 16.

[0030] In this configuration, light sources 16 within the same group are generally closer to each other than light sources in other groups. As will be described later, light sources 16 within the same group are associated with the same cavity.

[0031] In this main module 14a, the light diffusion element 23 extends opposite to the light source 16 and is illuminated by them. This diffusion element is in the form of a plate that extends substantially parallel to the circuit board 25. This diffusion element has two opposing faces, namely a back face directed toward the light source 16 and a front face directed toward the region of interest 8. For example, this diffusion element has a thickness between 2 mm and 8 mm.

[0032] Therefore, the light-diffusing element 23 is positioned such that its back surface directly receives at least a portion of the light beam emitted by the light source 16. In this example, "directly" is understood to mean that the light beam does not pass through any other optical elements before reaching the back surface of this diffuser. The light beam reflected by the reflector 21 is also understood to reach this diffuser "directly".

[0033] As the light beam diffuses through this light-diffusing element, it generates a secondary light beam spread out on its front surface, which allows for illumination of the region of interest 8. The diffusion angle of this diffusion element is, for example, between 20 and 140 degrees relative to a collimated light beam incident perpendicularly to it.

[0034] In this main module 14a, the reflector 21 is inserted between the circuit board 25 and the diffusion element, and therefore between the multiple light sources 16 and this diffusion element.

[0035] The reflector 21 includes walls, which in this example are peripheral walls 18a, 18b, and 18c, as well as a partition wall 19 separating the two cavities. These walls form cavities around the light sources 16. As clearly shown in Figures 3 and 4, each cavity is formed around a single group of light sources 16.

[0036] More specifically, each cavity is formed around a plurality of light sources 16 to maintain a sufficient size in order to enhance the uniformity of the secondary light beam while effectively utilizing the effect of the reflector 21. In this embodiment, this plurality consists of 12 light sources 16.

[0037] To guide the light beam toward the diffusing element, the cavity is widened in a direction that extends from the light source 16 toward this diffusing element. The walls around the cavity are reflective to guide the light beam toward the diffusing element. In this example, the reflector 21 is made of a plastic material with a thin metallic layer deposited on it, such as a coating containing aluminum, silver, or paint. In a variation, the reflector 21 may be made entirely of metal. A coating such as paint, or a metallic plating, can be deposited on the metallic material by chemical or physical deposition methods. This uses the following non-exclusive and non-limiting layer deposition techniques. That is, chemical vapor deposition (more generally known as the acronym CVD), atomic layer deposition (more generally known as the acronym ALD), for example, atomic layer deposition using Plasma-ALD (P-ALD) or Thermal-ALD (T-ALD) methods, molecular layer deposition (more generally known as the acronym MLD), layer deposition by cathode sputtering (more generally known as the "sputtering method"), and a combination of at least two of these layer deposition techniques.

[0038] These walls rise between the circuit board 25 and the diffusion element, and therefore between the multiple light sources 16 and this diffusion element. However, these walls do not directly contact either the circuit board 25 or the light sources 16 in order to avoid any short circuits. The fact that a cavity is formed "around" the group of light sources 16 is understood to mean that it fits into the vicinity of the group, protruding slightly from the circuit board 25 by a distance of, for example, between 0.5 mm and 3 mm.

[0039] In this configuration, the upper end of the light source on the side opposite to the circuit board 25 can still be placed within the corresponding cavity. Thus, the cavity has an inlet opening into which the light source 16 is placed.

[0040] The peripheral walls 18a, 18b, and 18c surround multiple light sources 16. That is, when arranged so that their ends are continuous, the peripheral walls 18a, 18b, and 18c surround all the light sources 16 on the main module 14a. In other words, the peripheral walls 18a, 18b, and 18c do not extend between two light sources 16. In the example shown in the drawing, the peripheral walls 18a, 18b, and 18c extend above the rectangular periphery on the circuit board 25. In this example, the peripheral walls 18a, 18b, and 18c surround all the light sources 16.

[0041] On the other hand, the partition wall 19 extends between the light sources 16. More specifically, the partition wall 19 extends between two adjacent groups of light sources 16, i.e., groups arranged side by side. In other words, the partition wall 19 separates two adjacent cavities. In this example, the partition wall 19 extends from one peripheral wall 18a, 18b, 18c to another peripheral wall 18a, 18b, 18c.

[0042] As can be clearly seen from Figures 3 and 4, the partition wall rises in the middle of the reflector 21 or on the inside of the reflector 21, in contrast to the peripheral walls 18a, 18b, and 18c that rise around the periphery of the reflector 21.

[0043] These walls extend from the bottom 17 of the cavity toward the optical diffusion element 23, each having a top 22a, 22b, the tops 22a, 22b being positioned at a first distance E1 with respect to the optical diffusion element 23 for the peripheral walls 18a, 18b, 18c and a second distance E2 with respect to the partition wall, the first distance E1 being smaller than the second distance E2. In this configuration, the heights of the peripheral walls 18a, 18b, and 18c limit the amount of light that can escape before reaching the diffusion element.

[0044] In the first embodiment where the distance E1 is zero, it should be noted that the back surface of the diffusion element is in contact with the peripheral walls 18a, 18b, and 18c. In this case, the light beam is effectively confined inside the reflector 21 between the circuit board 25 and the diffusion element.

[0045] Therefore, the structure of the reflector 21 generally allows for increased compactness of the main illumination module 14a while generating a uniform secondary light beam for illuminating the region of interest 8. It also makes the main module 14a more energy-efficient by increasing the amount of light reaching the optical diffusion element 23.

[0046] A notable feature of the reflector 21 structure, combined with the grouping of the light sources 16, is that it allows for the use of fewer light sources 16. In fact, the main module 14a is designed so that each light source generates a light beam that illuminates a portion of the diffuser element.

[0047] As described above, the device 2 also includes a function setting module 5. In this regard, such a function relates to the setting of the illumination and temperature of the light source 16 on the projector 3.

[0048] To set the lighting function, the module controls the vertical and / or horizontal movement of the projector 3, or the orientation of the projector 3, via the processing unit and each electric motor. This module can also control the light intensity of the main module 14a.

[0049] Referring to Figure 2, such an illumination device (2) allows for the diffusion of uniform illumination of the region of interest (8) across the light spectrum contained between 390 nm and 780 nm. It should be noted that when performing fluorescence testing, this illumination device 2 allows for the diffusion of uniform illumination having a light spectrum contained within the ultraviolet (UV) wavelength range between 100 nm and 400 nm. This spectrum is divided into three main subbands: UV-A (315 nm to 400 nm), UV-B (280 nm to 315 nm), and UV-C (100 nm to 280 nm). For precious stones such as diamonds, exposure to such UV radiation results in the emission of fluorescence of various colors. In many cases, the color is blue. In fact, 98% of all fluorescent diamonds are this color. However, other colors such as white, green, pink, or yellow fluorescence also exist. The color of fluorescence depends on the physical composition of the atomic structure inside the diamond.

[0050] Furthermore, in this apparatus 2, the auxiliary lighting modules 14b are preferably located on each side of the projector 3. These are configured to attenuate light disturbances that may be caused by light sources present in the work environment whenever the light intensity in the work environment exceeds a predetermined threshold.

[0051] It should be noted that such a lighting device 2 offers far better performance than a lightbox used to verify the color reproduction of gemstones.

Claims

1. A device (2) for illuminating a gemstone (10), comprising a light projector (3) provided with a main illumination module (14a) for generating illumination specially configured to reveal the properties of the gemstone (10), wherein the main module (14a) comprises a circuit board (25) including a plurality of light sources (16), each emitting a light beam, and light diffusing elements arranged opposite the plurality of light sources (16), and the main module (14a) is arranged between a support element (7) and the light diffusing elements. The apparatus comprises a reflector (21), the reflector (21) having at least one cavity capable of reflecting at least a portion of the light beam toward the light-diffusing element, each cavity being formed by a bottom (17) and peripheral walls (18a, 18b, 18c), the peripheral walls (18a, 18b, 18c) extending from the bottom (17) toward the light-diffusing element (23), and the top (22a) of each thereof being positioned at a first distance (E1) from the light-diffusing element.

2. The apparatus according to claim 1, wherein the reflector (21) comprises two cavities capable of reflecting at least a portion of the light beam toward the light-diffusing element, each cavity being formed by a bottom (17), a peripheral wall (18a, 18b, 18c) and a partition wall (19) separating it from the other cavity, the wall extending from the bottom (17) toward the light-diffusing element (23), the tops (22a, 22b) of the light-diffusing element being positioned at a first distance (E1) and a second distance (E2) toward the partition wall (19), the first distance (E1) being less than the second distance (E2).

3. The apparatus according to claim 1, wherein the light source (16) includes an electroluminescent element.

4. The apparatus according to claim 1, wherein the light source (16) has an adjustable color temperature that varies between 2,500K and 7,000K, preferably between 5,700K and 6,300K.

5. The apparatus according to claim 1, further comprising a module (5) for setting a function to be performed by the apparatus (2), wherein the module (5) comprises an operating unit (15a) for controlling the function and a screen (15b) for transmitting information relating to the function.

6. The apparatus according to claim 1, comprising a module (5) for setting a function to be performed by the apparatus (2), wherein the module (5) comprises an operating unit (15a) for controlling the function and a screen (15b) for transmitting information relating to the function, and the function relates to setting the illumination and temperature of the light source (16).

7. The apparatus according to claim 1, comprising an articulated arm (12) having a first part (4a) and a second part (4b), connected at one end of the two parts thereof.

8. The apparatus according to claim 1, comprising an articulated arm (12) having a first portion (4a) and a second portion (4b), connected at one end thereof, wherein the first portion (4a) and the second portion (4b) each have at least one motor for controlling the horizontal and / or vertical movement of the projector (3) relative to the gemstone (10).

9. The apparatus according to claim 1, further comprising a sub-module (14b), the sub-module (14b) being positioned on the side of the projector (3) and configured to attenuate light disturbances that may be caused by a light source outside the apparatus (2).

10. A system (1) for testing the properties of a gemstone (10), comprising an illumination device (2) and a support element (7) as described in claim 1, wherein the illumination device (2) is fixed to the support element (7), and the illumination device (2) is configured to produce illumination of a region of interest (8) contained on a plate (6) in the support element (7), the region of interest (8) includes the gemstone (10) that can be handled by a user.

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