Mee Gem Sorting

Abstract

A method for sorting gemstones includes: receiving one or more gemstones at a collection location; determining at the collection location that one of the one or more gemstones is correctly oriented; transferring the correctly oriented gemstone from the collection location to a movable surface using a robotic arm; transporting the gemstone on the movable surface to one or more measurement locations; measuring one or more properties of the gemstone at the one or more measurement locations while the gemstone is supported on the movable surface; and sorting the gemstone based on the measured one or more properties.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for sorting gemstones. In particular, although not exclusively, the present invention relates to a method and apparatus for sorting very small gemstones having a size between 0.1 and 0.3 centimeters. Background Art

[0002] Reference is made to various techniques for sorting gemstones, particularly very small gemstones. Advanced screening instruments such as DiamondSure™ and DiamondView™ can be used to test whether cut and polished diamonds are natural or synthetic. Typically, such screening involves measuring the way light is absorbed by or emitted from the diamond. Before screening begins, the stone being tested may be placed, preferably "table down," in a precise position on a measuring surface or holder. In this case, the "table" is the largest center face of the crown (e.g., the top or exposed portion of the stone when mounted in a ring). WO2018 / 115889 proposes an apparatus that can be used to screen gemstones and sort the stones based on the screening results. Summary of the invention

[0003] In one aspect, a method of sorting gemstones is provided. The method includes: receiving one or more gemstones at a collection location; determining a correct orientation of the one or more gemstones at the collection location; transferring the correctly oriented gemstones from the collection location to a movable surface using an automated arm; transporting the gemstones to one or more measurement locations on the movable surface; measuring one or more properties of the gemstones at the one or more measurement locations while the gemstones are supported on the movable surface; and sorting the gemstones based on the one or more measured properties. The gemstones may be substantially between 0.1 and 0.3 points.

[0004] The movable surface may be a rotatable disc. The transferring may include: stopping the rotatable disc; dispensing the gemstone onto the surface of the rotatable disc; and rotating the rotatable disc by a predetermined angle. The predetermined angle may be 9 degrees.

[0005] The method may include transferring a properly oriented first gemstone onto the movable surface while the movable surface is stationary, while measuring one or more properties of a second gemstone at at least one of the one or more measurement locations. The method may include transferring a properly oriented first gemstone onto the movable surface while the movable surface is stationary, while measuring one or more properties of a second gemstone at at least one of the one or more measurement locations, and simultaneously dispensing a third gemstone off the movable surface.

[0006] The method may include measuring one or more properties of a first gemstone at at least one of the one or more measurement locations while transporting a second gemstone on a movable surface, wherein the movable surface is non-stationary. One of the at least one measurement location may include a luminescence measurement unit. One of the at least one measurement location may include a photoluminescence measurement unit. Measuring at least one of the one or more properties of the gemstone may include illuminating the gemstone with a light beam having an angle of incidence of substantially 10 degrees measured from a horizontal plane.

[0007] The method may include transporting a gemstone through a measurement location during measurement. Each of the one or more gemstones may be sorted based on one or more measurement results identifying the gemstone as natural or synthetic. The method may include moving the movable surface at a first speed and a second speed, wherein the second speed is less than the first speed.

[0008] The method may include sorting the gemstones by further transporting the gemstones to a dispensing location and dispensing the gemstones off the movable surface based on the measured one or more properties of the gemstones.

[0009] The method may include receiving one or more gemstones from a hopper at a collection location and controlling the flow of the one or more gemstones through the hopper to the collection location. The method may include controlling the flow of the one or more gemstones via an end hopper wall, the end hopper wall defining an orifice at a bottom thereof. The hopper may be provided with at least one substantially curved inner surface.

[0010] The method may include obtaining an image of one of the one or more gemstones at a collection location; and analyzing the obtained image to determine the orientation of the gemstone. In the event that the orientation is determined to be correct, the method may include designating the imaged gemstone for transfer to a removable surface. When the orientation is determined to be incorrect, the method may include vibrating the collection location so that the imaged gemstone is reoriented.

[0011] The method may include vibrating the collection location once all gemstones determined to be correctly oriented at the collection location have been transferred from the collection location to the movable surface.

[0012] When the imaged gemstone is determined to be in a table-down orientation, the orientation may be determined to be correct.

[0013] The method may include providing a vacuum nozzle at one end of the robotic arm, supplying negative pressure to an orifice of the vacuum nozzle so as to pick up individual gemstones using the orifice, and supplying positive pressure to the vacuum nozzle so as to dispense the gemstones out of the orifice onto a movable surface. The method may include providing an annular collar to the vacuum nozzle, the collar substantially surrounding the orifice while the gemstones are dispensed out of the orifice.

[0014] The method may comprise measuring one or more properties of the gemstone at one or more measurement locations while the movable surface is stationary and measuring one or more properties of the gemstone at one or more measurement locations while the movable surface is not stationary.

[0015] In another aspect, an apparatus for sorting gemstones includes: a collection location configured to receive one or more gemstones; an image capture device configured to obtain one or more images of the one or more gemstones at the collection location; a processor configured to analyze the one or more images and determine whether one or more of the one or more gemstones are properly oriented; an automated arm configured to transfer the properly oriented gemstones from the collection location to a movable surface; the movable surface configured to transport the gemstones to one or more measurement locations; and the one or more measurement locations configured to measure one or more properties of the gemstones while the gemstones are supported on the movable surface. The gemstones may be substantially between 0.1 and 0.3 points.

[0016] The movable surface may be a rotatable disc. The apparatus may further comprise a controller configured to incrementally move the rotatable disc by a predetermined angle, preferably 9 degrees. The controller may be configured to control the movable surface to be stationary during the transfer of the gemstone onto the movable surface. The controller may be configured to control the movable surface to be non-stationary during the measurement of one or more properties of the gemstone.

[0017] One of the at least one measurement location may comprise one of a luminescence measurement unit, a photoluminescence measurement unit. The apparatus may further comprise an illumination arrangement at one or more measurement locations configured to illuminate the gemstone supported on the movable surface at a predetermined illumination angle, preferably an illumination angle of substantially 10 degrees measured from a horizontal plane.

[0018] The movable surface may be controllable to move at a first speed and a second, lower speed, the movable surface being configured to move at the second, lower speed as the gemstone is transported through one of the one or more measurement locations.

[0019] The apparatus may include one or more dispensing locations, each dispensing location including a dispensing mechanism and a dispensing bin. The apparatus may include a hopper configured to provide one or more gemstones to a collection location. The hopper may be provided with an end wall defining an orifice at a bottom thereof, and may be configured to control the flow of gemstones to the collection location via the orifice.

[0020] The body of the hopper may be inclined towards the orifice generally at an angle of substantially 3 degrees measured from the horizontal. The end wall may be inclined inwardly at an angle of substantially 75 degrees measured from the horizontal.

[0021] The apparatus may include a vibration mechanism configured to vibrate the collection location to properly orient the one or more gemstones at the collection location.

[0022] The apparatus may include a vacuum nozzle connected to an end of a robotic arm, the vacuum nozzle including an aperture for receiving a gemstone and an annular collar configured to surround the aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An apparatus for sorting gemstones is shown;

[0024] Figure 2a shows a hopper and a light table;

[0025] Figure 2b A schematic diagram showing a visual system;

[0026] Fig. 2c shows an image of the light table;

[0027] Figure 3a , Figure 3b and Figure 4 A hopper is shown;

[0028] Figure 5 , Figure 6a , Figure 6b , Figure 6c and Figure 7 The nozzle is shown;

[0029] Figure 8a and Figure 8b The optical arrangement is shown;

[0030] Fig. 9 showing the dispensing mechanism and dispensing location;

[0031] Fig.10 It is a flow chart of a method for sorting gemstones. DETAILED DESCRIPTION

[0032] This article refers to Figures 1 to 10 Embodiments of apparatus and methods for sorting gemstones are described. Although reference may be made to diamonds, the invention is not limited thereto and may encompass other gemstone types.

[0033] Natural diamonds consist exclusively of diamonds formed through long-term natural geological processes. Synthetic diamonds are man-made stones made through industrial processes such as high pressure and high temperature (HPHT) and chemical vapor deposition (CVD).

[0034] Synthetic diamonds have widespread industrial applications but do not attract the high value associated with natural diamonds of similar color and quality. When in an unpolished state, synthetic diamonds may be relatively easy to distinguish from natural diamonds, however, once polished and cut into a gemstone, identifying the stone as synthetic may be more difficult.

[0035] Advanced screening instruments such as DiamondSure™ and DiamondView™ can be used to test whether cut and polished diamonds are natural or synthetic. Typically, this screening involves measuring the way light is absorbed by or emitted from the diamond. Before screening begins, the stone being tested is placed, preferably "table down," in a precise position on a measuring surface or holder. In this case, the "table" is the largest center face of the crown (e.g., the top or exposed part of the stone when mounted in a ring). WO2018 / 115889 proposes an apparatus that can be used to screen gemstones and sort the stones based on the screening results.

[0036] In addition to screening larger individual stones, you may also wish to screen a number of smaller diamonds, including cut and polished stones (sometimes referred to as melee diamonds). Melee diamonds are a trade term that does not define a specific size range, but in practice can be considered to refer to stones or chips smaller than about 0.2 carats (20 points). These stones may have a diameter of less than about 3.5 mm. However, the term melee diamonds may also include very small stones of about 0.001 to 0.003 carats (0.1 to 0.3 points) with a diameter of about 0.65 to 0.90 mm.

[0037] Due to their small size, melee diamonds are often sold in packages or batches. Since a package can contain hundreds of stones, synthetic diamonds and non-diamond materials (e.g., glass and cubic zirconia) may be mixed with natural stones. Screening of melee diamonds can be extremely time-consuming, as each stone must be individually tested and therefore individually placed in the correct orientation.

[0038] For very small melee stones (e.g., 0.1 to 0.3 pt stones), as described above, other problems may be, but are not limited to: stones getting lost or trapped in sorting equipment; static charges being induced on the stones, making them more difficult to manipulate mechanically and manually; and industry supplied stone packages sometimes have a very light film of oil due to not being properly cleaned after manufacturing, making the stones sticky and resulting in poor feeding efficiency. The surface area of ​​very small melee stones is large compared to their volume, so the static charge induced on these small stones by known feeding and orientation techniques can be high. Often, mitigation of statically charged stones may require the use of an ionizer and / or closed loop humidifier system.

[0039] In one embodiment, an apparatus for sorting gemstones includes: a collection location configured to receive one or more gemstones; an image capture device configured to obtain one or more images of the one or more gemstones at the collection location; a processor configured to analyze the one or more images and determine whether one or more of the one or more gemstones are correctly oriented; an automated arm configured to transfer the correctly oriented gemstones from the collection location to a movable surface; the movable surface configured to transport the gemstones to one or more measuring locations; and the one or more measuring locations configured to measure one or more properties of the gemstone while the gemstone is supported on the movable surface.

[0040] In one embodiment, the method includes: receiving one or more gemstones at a collection location; determining at the collection location that one of the one or more gemstones is correctly oriented; transferring the oriented gemstone from the collection location to a movable surface using a robotic arm; transporting the gemstone to one or more measurement locations on the movable surface; measuring one or more properties of the gemstone at the one or more measurement locations while the gemstone is supported on the movable surface; and sorting the gemstone based on the measured one or more properties.

[0041] In certain embodiments, the gemstone is a diamond, optionally a melee diamond. The gemstone may be between about 0.1 and 0.3 points (e.g., between about 0.001 and 0.003 carats, with a diameter of about 0.65 mm to 0.90 mm). In one embodiment, the diameter or largest dimension of the gemstone is less than 0.8 mm. The gemstone may be a relatively small, round, bright polished diamond having a table and a culet, particularly a cut diamond. Other gemstone cuts and shapes are also contemplated.

[0042] The apparatus according to the present invention is designed with very small melee gemstones in mind. Known apparatus designed to manipulate larger gemstones would need to be adapted in order to sort such very small gemstones.

[0043] In one embodiment, the apparatus comprises: a movable surface or platform configured to support gemstones thereon; one or more measuring locations; and one or more dispensing locations. The apparatus may also comprise a feeder arrangement configured to feed a package comprising a plurality of gemstones onto the movable surface. In one embodiment, the feeder arrangement comprises a collection area from which individual gemstones may be collected (picked up) and transferred one by one to the movable surface. The collection area also serves as an orientation area, where the gemstones are oriented into the most stable orientation. The feeder arrangement may also comprise a hopper configured to receive a plurality of gemstones therein, and the gemstones may be dispensed from the hopper onto the collection area. The feeder arrangement may also comprise a transfer mechanism configured to pick up individual gemstones from the collection area and transfer them to the movable surface.

[0044] exist Figure 1 In the illustrated embodiment, the apparatus 10 configured to sort gemstones includes a movable surface in the form of a rotatable disc. The rotatable disc is configured to transport gemstones supported thereon to one or more measurement locations 40a, 40b and one or more dispensing locations 70. One or more measurement locations 40a, 40b and one or more dispensing locations 70 are arranged around the circumference of the rotatable disc. The upper surface of the rotatable disc is substantially horizontal and flat. The surface of the disc that transports gemstones is substantially intact so that it does not include depressions or compartments that would trap gemstones.

[0045] like Figure 1 The advantage of the illustrated disc configuration may be that multiple stations (e.g., measurement position, dispensing position) may be accommodated in a compact space. In addition, for example, any gemstone that is not dispensed for any reason at the dispensing position may be transported by the disc back to the measurement position. However, in other embodiments not illustrated herein, the movable surface may be a linear conveyor.

[0046] like Figure 1 As shown, each dispensing position 70 includes a dispensing mechanism such as a rotating wheel 75 and a dispensing bin 80 or container. In some embodiments, each dispensing bin is provided with a corresponding dispensing mechanism. Each dispensing bin is designated to receive gemstones with predetermined measurements. In alternative embodiments not shown herein, the dispensing mechanism includes a push rod, a low pressure (vacuum) nozzle, a compressed air nozzle, etc., which is configured to dispense or remove a specific gemstone from the movable surface.

[0047] exist Figure 1 In the embodiment shown, the feeder arrangement comprises a hopper 50, a collection area in the form of a light table 60 and a transfer mechanism in the form of an automated arm 30, which comprises a pick-up nozzle. However, it will be appreciated that in other embodiments one or more components of the feeder arrangement are modified or replaced.

[0048] Figure 2a and Figure 2bShown in more detail Figure 1 The feeder arrangement is shown in the embodiment of FIG. 1 . In this embodiment, the hopper 50 is configured to receive gemstones therein and move the gemstones toward the end of the hopper adjacent to the light table 60 (collection area). The hopper 50 includes a vibrating mechanism (not shown here) that causes the body of the hopper 50 to vibrate, thereby moving the gemstones along the body of the hopper 50 and toward the light table 60. However, the hopper 50 does not necessarily orient the gemstones in any particular orientation.

[0049] As will be described in more detail below, in one embodiment, the hopper 50 is configured to dispense gemstones onto the light table 60 (collection area). However, the hopper 50 is configured to control or limit the flow of gemstones onto the light table 60 (collection area). In the embodiment of FIG. 2a , this control is achieved by providing a baffle at the end of the hopper 50 adjacent to the light table 60. The baffle includes or is formed by an end wall or plate that defines a small orifice or aperture at the bottom of the hopper 50.

[0050] In the embodiment of FIG. 2a, the optical table 60 provides a collection area or pick-up zone where gemstones can be picked up by the robotic arm 30 and transferred one by one to the movable surface 20. The optical table 60 of FIG. 2a includes a substantially flat surface or bottom 65 surrounded by one or more walls. The shape of the optical table 60 is substantially square, but other configurations of the collection area can be provided. In some embodiments, the optical table 60 is formed of a plastic material or the like.

[0051] In one embodiment, the optical table 60 is configured to receive one or more gemstones from the hopper 50 on a flat surface or bottom 65 of the optical table 60. It will be appreciated that the gemstones may rest in a number of different orientations as they fall through the orifice of the hopper 50 or are transferred from the hopper 50 onto the flat surface 65 of the optical table 60. For example, the cut gemstone may rest on a substantially flat table surface, or may rest on a pavilion facet.

[0052] To facilitate placement of the gemstone on the movable surface 20 and / or to ensure accurate measurement of the gemstone at one or more measurement locations 40a, 40b, it may be desirable to orient the gemstone in a table-down position such that the gemstone rests on a substantially flat table surface as described above. The table-down position generally represents the most stable orientation for a cut gemstone, e.g., an orientation from which the gemstone is least likely to move.

[0053] As shown in FIG. 2a, the light table 60, or at least its flat bottom 65, includes a vibrating mechanism (not shown here) that is configured to periodically vibrate the light table 60 to reorient any gemstone resting on the bottom 65. As the light table 60 vibrates in this manner, any gemstone that is not yet in the table-down position may be reoriented. Once the gemstone is in the table-down position, the light table 60 is configured so that the gemstone is unlikely to be reoriented by further vibration of the light table 60. In other words, the gemstones retained in the light table 60 are repeatedly vibrated until they are in the table-down position, where they remain in the table-down position even if further vibration occurs. In this regard, the light table 60 provides an orientation area as well as a collection area. A further description of the vibration of the light table 60 will be provided below.

[0054] In the embodiment of FIG. 2a , the transfer mechanism (e.g., automated arm 30) is a robotic arm controlled by a controller (not shown). A suitable robotic arm may be provided by Asyril SA, and / or may be a SCARA type robot. The robotic automated arm 30 is equipped with a pick-up nozzle configured to pick up individual gemstones from the flat surface 65 of the optical table 60 and transport and place the individual gemstones one at a time onto the movable surface 20. The configuration and operation of the pick-up nozzle will be described in more detail below.

[0055] In some embodiments, the robotic arm 30 and the light table 60 are controlled by the same controller. In other words, the controller is configured to control the vibration of the light table 60 and the activation or operation of the robotic arm 30. In some embodiments, a single controller controls the overall operation of all components of the sorting device.

[0056] exist Figure 2b In the embodiment shown in the schematic diagram of , the controller 34 communicates with an image capture device such as a camera. The image capture device inspects the light table 60 (collection area) from above (or below) the light table 60 (e.g., captures an image thereof). The captured image includes at least some of the gemstones supported on the bottom 65 of the light table 60, and may include all of the gemstones supported on the bottom 65. In one embodiment, the image capture device is operated by the controller 34. The captured image can be a color or black and white still image of the light table 60 (or a portion thereof) and / or a color or black and white video of the light table 60 (or a portion thereof). The image capture device can continuously or periodically illuminate the surface of the light table 60 using a light source (not shown). The illumination of the light table can follow the vibration of the light table.

[0057] like Figure 2bAs shown, a processor 36 is provided in communication with the controller 34. The processor 36 is configured to operate software that allows identification of gemstones supported on the bottom 65 of the light table 60. For example, the processor 36 may be configured to analyze one or more images of gemstones present in the light table 60 captured by the image capture device. In the case where the one or more images are captured from above (or below) the light table 60, a round brilliant cut gemstone oriented in a table-down configuration will appear substantially round in the captured image. Conversely, when imaged from above (or below), a round brilliant cut gemstone that is not in a table-down configuration will appear different (e.g., substantially non-round) in the captured image. Therefore, the processor analyzes one or more images of the gemstone and determines whether a particular gemstone in the light table 60 is oriented in a table-down position based on such analysis of the one or more images. It will be appreciated that in the case of sorting gemstones of different cuts / shapes, the analysis and orientation identification may be performed based on different criteria.

[0058] The above analysis may also include determining whether the imaged gemstone is a single gemstone or whether the image includes two or more gemstones that are in direct contact with each other. In this way, picking up multiple gemstones from the light table can be avoided.

[0059] In one embodiment, the processor 36 signals or indicates to the controller 34 that one or more gemstones in the light table 60 have been determined to be in the table-down configuration, and that the one or more gemstones are designated to be individually picked up by the transfer mechanism (e.g., the robotic arm 30). The controller 34 then actuates the robotic arm 30 to individually pick up the designated one or more table-down gemstones from the light table 60. In other words, gemstones in the light table 60 that are not in the table-down configuration are not picked up by the robotic arm 30. It will be appreciated that for gemstones of different shapes, the most stable configuration may not be the table-down configuration, in which case the processor and controller may be configured to designate stones for picking up based on different criteria.

[0060] The controller 34 is configured to periodically vibrate the light table 60 (e.g., cyclically vibrate) using a vibration mechanism so that any gemstones that are not in a face-down configuration can be reoriented by the vibration of the light table 60. The frequency, length, and vibration level of the light table 60 are determined by the controller 34 and / or software operated by the processor 36 based on the specific application (e.g., the number and / or size of gemstones to be reoriented). Thus, the light table 60 also provides an orientation or reorientation zone.

[0061] In one embodiment, the controller 34 is configured to optimize the transfer rate of gemstones from the optical table 60 to the movable surface by determining the optimal time to vibrate the optical table 60. For example, the controller 34 may wait to vibrate the optical table 60 until all table-down gemstones (gemstones in the most stable orientation) have been picked up and transferred to the movable surface. Alternatively or additionally, the controller 34 may vibrate the optical table 60 while there are still some table-down gemstones present on the optical table 60.

[0062] In one embodiment, the controller 34 is configured to optimize the transfer rate of gemstones by specifying the order in which correctly oriented gemstones should be picked up by the robotic arm. Although correctly oriented gemstones are less likely to reorient from the table-down position during vibration, these gemstones may still move horizontally and laterally within the optical table 60 during vibration. The controller 34 can instruct the robotic arm to pick up the correctly oriented gemstone that is closest to the robotic arm (or other predetermined point).

[0063] FIG. 2c shows a captured image of a light table or collection area. In this non-limiting example, the image is shown in the context of a software program run by a processor that allows analysis of gemstones present in / on the light table and designation of one or more correctly oriented gemstones for easy pickup by an automated arm (not shown). As can be seen from FIG. 2c, the imaged light table contains a number (approximately 50-60) of small gemstones 90, which are imaged in silhouette in this example. If the silhouette of each gemstone indicates that the gemstone is not correctly oriented (e.g., table facing down), the gemstone may be rejected as not being correctly oriented. Conversely, in this example, if the silhouette of a gemstone having a substantially circular silhouette image indicates that the gemstone table is facing down, the gemstone may be accepted as being correctly oriented.

[0064] The use of a light table as a collection area / orientation area between the hopper and the movable surface can increase the throughput of the sorting device compared to devices that do not include these features. In one embodiment, gemstones are placed on the movable surface at a rate of one stone per second. This can be achieved because there is no need to wait for a single gemstone to appear in the correct (e.g., table-down) orientation for the automated arm to pick up. Instead, multiple gemstones can be distributed from the hopper to the light table, at least some of which may be in the correct (e.g., table-down) orientation. These table-down gemstones can be picked up by a transfer mechanism (e.g., a robotic arm). Providing a light table also allows the orientation of the gemstone to be pre-checked before picking up and transferring, thereby increasing the accuracy and efficiency of the device.

[0065] In one example, once the controller identifies a number of properly oriented stones, the automated arm transfers the identified stones individually to the movable surface. If the number of stones (total) on the light table is below a given number determined by the controller, the hopper may be activated to add more stones to the light table. The controller then evaluates the stones as described above, and any stones that are correctly oriented are picked up by the automated arm. In one example, once all correctly oriented stones present in the light table have been transferred to the movable surface, the light table vibrates again, and so on. Alternatively or additionally, the light table vibrates between each pick to provide additional table-down gemstones (e.g., pick candidates) for picking. In one embodiment, the controller avoids vibrating the light table during picking, and / or avoids dispensing additional gemstones from the hopper onto the light table during picking.

[0066] The above arrangement means that there is usually always at least one correctly oriented gemstone at the light table ready to be picked up by the transfer mechanism (automatic arm). In fact, there may be several correctly oriented gemstones to choose from for picking up (e.g., multiple pick-up candidates). Therefore, there is no need to wait for any particular stone to be correctly oriented before picking up. Identifying the stone as correctly oriented (e.g., by an image capture device and processor) enables multiple gemstones to be located in the pick-up area. The use of a hopper that gradually feeds a bag of gemstones onto the light table prevents overloading of the light table and helps to increase the accuracy of the orientation determination.

[0067] exist Figure 2b In the illustrated embodiment, the optical table 60, the robotic arm 30, the image capture device, the controller 34, and the processor 36 comprise a vision system. The vision system may also include a feeder arrangement such as a hopper 50. Optionally, the hopper 50 is controlled by the controller 34. Alternatively, the hopper 50 is independently controlled. Similarly, a vibration mechanism configured to vibrate the hopper and / or the optical table may be integrated or may be separate.

[0068] Referring back to FIG. 2a, in this embodiment, the robotic arm 30 is configured to pick up an individual gemstone 90 from the bottom 65 of the optical table 60 using a pick-up nozzle, and transport or transfer the individual gemstone 90 held on the pick-up nozzle to the movable surface 20, and place (e.g., release) the gemstone 90 onto the movable surface 20. As previously discussed, the gemstone 90 is placed on the movable surface 20 in a predetermined orientation.

[0069] Typically, table-down (or culet-up) is the most stable orientation for a cut gemstone. Thus, placing the gemstone on the movable surface in a table-down orientation ensures that the gemstone does not move from its position on the movable surface when subsequently transported to the measurement / dispensing position. In other words, once placed on the movable surface, the gemstone remains substantially stationary and in the same orientation relative to the movable surface until it is dispensed or transferred away from the movable surface. Thus, there is no need to perform any reorientation of the gemstone once it has been placed on the movable surface. It will be appreciated that until the gemstone is placed on the movable surface, the transport of the gemstone to the measurement position is not initiated.

[0070] It will be appreciated that in alternative embodiments not shown herein, the components of the feeder arrangement described above are used in isolation. For example, the optical table 60 may be used with an alternative hopper and / or an alternative automated arm or an alternative device configured to transfer gemstones from the optical table to a movable surface. Similarly, the hopper 50 may be used with an alternative to the optical table and / or automated arm. The automated arm 30 may likewise be used with an alternative to the optical table and / or an alternative hopper, etc.

[0071] In one embodiment, the movable surface 20 is controlled by a controller (not shown) to move in predetermined uniform increments (e.g., intermittently). In one embodiment, the controller that controls the movable surface 20 is the same controller that operates the transfer mechanism and / or the light table and hopper; alternatively, the movable surface 20 and the transfer mechanism are independently controlled.

[0072] In the embodiment of FIG. 2a, the movable surface is a rotatable disc that is operated by a stepper motor (not shown) to move intermittently. The rotatable disc is controlled to rotate in uniform increments of about 9 degrees (e.g., moving an angle of 9 degrees during each rotation). That is, the rotatable disc of this embodiment is configured to rotate an angle of nine degrees and then stop. In one embodiment, the duration of the stationary period of the movable surface depends on the availability of correctly oriented gemstones in the light table. For example, in the case where one or more gemstones are properly oriented and can be used for picking up and transferring, the movable surface (e.g., rotatable disc) is stationary for less than about 200ms. In the case where there is no gemstone correctly oriented in the light table and the light table needs to be vibrated to provide a correctly oriented stone for picking up, the movable surface can be stationary for up to 3 seconds.

[0073] While the movable surface 20 is stationary or stopped, the automated arm 30 or alternative feeder arrangement assembly may place individual gemstones 90 on the movable surface 20. Once the automated arm 30 has placed a single gemstone 90, the movable surface 20 is controlled to move another predetermined increment and then stops. Another individual gemstone 90 may then be placed on the movable surface 20 by the automated arm 30, and the movable surface 20 is then controlled to move another predetermined increment. This process may be repeated until all gemstones present in the optical table 60 or alternative feeder arrangement assembly have been transferred to the movable surface 20. Similarly, this process may be repeated until all gemstones present in the hopper 50 or alternative feeder arrangement assembly have been transferred to the movable surface 20.

[0074] It will be understood from the above description that each gemstone 90 may be placed on the movable surface 20 at a predetermined distance from the previous gemstone 90. In other words, the gemstones 90 placed on the movable surface 20 are substantially equidistant from each other.

[0075] Once placed on the movable surface 20, the gemstone is transported toward one or more measurement locations 40a, 40b as the movable surface 20 is intermittently moved. Figure 1 As shown, the movable surface 20 and one or more gemstones supported thereon pass through one or more measurement positions 40a, 40b as they move incrementally. The speed of the movable surface 20 may be constant during the movement cycle, or may include acceleration and / or deceleration periods, as will be described below.

[0076] In one embodiment, the movable surface 20 is controlled so that as or when each of the one or more gemstones reaches one or more measurement positions 40a, 40b, the movable surface 20 is stationary. In this case, measurements of the stationary individual gemstones can therefore be obtained. However, in some embodiments, one or more measurements of the individual gemstones are obtained while the gemstones on the movable surface are in motion.

[0077] In one embodiment, during a time interval in which the movable surface 20 is stationary, a first gemstone already present on one portion of the movable surface 20 is measured at one of the one or more measurement positions, while, during the same time interval, a different second gemstone is placed on a different second portion of the movable surface 20, for example by the robotic arm 30. Of course, additional gemstones may be present on the movable surface between the first and second gemstones.

[0078] As a non-limiting example, in a first time interval in which the movable surface is stationary or not moving, the automated arm places a first gemstone on the movable surface. The movable surface then moves a predefined distance or angle. In a second time interval in which the movable surface is stationary or not moving, the first gemstone arrives at a first measurement position and a measurement of a property of the first gemstone is obtained. During this second time interval, the automated arm places a second gemstone on the movable surface. The movable surface then moves a predefined distance or angle. In a third time interval in which the movable surface is stationary or not moving, the first gemstone arrives at a second measurement position and a measurement of a different property of the first gemstone is obtained. During this third time interval, the second gemstone arrives at the first measurement position and a measurement of a property of the second gemstone can be obtained. Additionally, during the third time interval, the automated arm places a third gemstone on the movable surface.

[0079] The above non-limiting example also includes dispensing gemstones at the dispensing locations. For example, during a fourth time period when the movable surface is stationary or not moving, a first gemstone arrives at the dispensing location and is dispensed or removed from the movable surface; a second gemstone arrives at the second measurement location; a third gemstone arrives at the first measurement location; and the automated arm places a fourth gemstone on the movable surface.

[0080] The placement, measurement, and distribution of stationary gemstones may be advantageous, particularly in the case of very small gemstones as described above. However, as described above, in some embodiments, one or more measurements of an individual gemstone are obtained while the gemstone is moving. In some embodiments, a first measurement of a gemstone is obtained while the gemstone is stationary, and a second measurement of the same gemstone is obtained while the gemstone is moving. In one embodiment, the speed of the movable surface during the time period in which the second measurement is obtained is lower than the speed of the movable surface at other times. For example, the movable surface may be accelerated to a maximum speed or decelerated from a maximum speed while obtaining a measurement of the gemstone.

[0081] Now refer to Figure 3a , Figure 3b and Figure 4 Discussing further details of the hopper 50. As described above, in one embodiment, the hopper 50 is configured to vibrate periodically or continuously to move or transport one or more gemstones from one end of the hopper 50 to the other end.

[0082] exist Figure 3a , Figure 3b and Figure 4 In the illustrated embodiment, the hopper 50 includes a trough-shaped body 52 (see Figure 3b ), terminating at each end in a substantially vertical or slightly inwardly inclined end wall 58, 59 or plate. In one example, one or both of the end walls 58, 59 are inclined inwardly about 75 degrees relative to the horizontal plane. Figure 4As best shown in FIG. 1 , the hopper body 52 generally slopes from one end wall 59 to the other end wall 58. In one example, the hopper body 52 has an overall downward slope of about 3 degrees relative to horizontal from a rear portion adjacent the end wall 59 to a front portion adjacent the end wall 58. The hopper body 52 is configured to receive a plurality of gemstones therein.

[0083] One end wall 58 defines a small orifice or aperture at its bottom. End wall 58 and orifice 56 together form a baffle that restricts or controls the flow of gemstones out of hopper 50, for example, during a single vibration cycle. The diameter and / or shape of orifice 56 may be specifically configured for the size of the gemstones to be sorted.

[0084] like Figure 3a As best shown in FIG. 1 , once the gemstones exit the hopper body 52 through the aperture 56 at the bottom of the end wall 58, the gemstones are received and directed by a chute 54 attached to or integrally formed with the hopper body 52. ​​In this embodiment, the chute 54 defines a channel at its bottom that directs or controls the flow of the gemstones so that the gemstones can be reasonably accurately dispensed from the hopper 50 to the next component, such as the light table 60 (collection area).

[0085] Advantageously, the body 52 and end walls 58, 59 of the hopper 50 are configured so that gemstones, particularly very small gemstones, are less likely to become stuck or trapped. In particular, the shape of the walls of the hopper body 52 avoids corners where gemstones may become trapped or collect. In some embodiments, the hopper body 52 and / or the end walls 58, 59 are not flat, but are gently curved and convex in cross-section. Thus, the shape deviates from a V-shape in cross-section because the walls are curved and sharp corners are avoided where the side walls meet. Sharp corners may cause stones to become stuck. Likewise, this curvature reduces the risk of gemstones sticking to the inner surface of the hopper body because the contact area between the gemstones and the inner surface of the hopper body is reduced.

[0086] This is particularly problematic in the case of sorting very small cut stones (e.g., 0.1 to 0.3 point stones) because the force of gravity on these stones may be less than the force that causes sticking. Flat gemstone facets may "stick" to any flat surface, and are so small that any flat interior surface of the hopper would be a potential sticking point. Therefore, instead of a flat surface, a curved surface reduces this problem. Whether the result of grease on the stone or static charge, sticking can result in an incomplete sort of a bag of gemstones, resulting in inefficiencies in processing the bag, or even stones being lost. Sticking can be further reduced by improving stone cleanliness and utilizing humidity (static) control.

[0087] Now refer to Figure 5 , Figure 6a , Figure 6b , Figure 6c and Figure 7Discuss more details of the pick-up nozzle of the robot's automatic arm 30. In this illustrated embodiment, Figure 5 , Figure 6a , Figure 6b and Figure 6c is a cross-sectional view of the pick-up nozzle of the automatic arm 30, Figure 7 It is a perspective view.

[0088] In this embodiment, the pick-up nozzle includes: an elongated nozzle body 32 defining a central bore 33 terminating at a lower end of the nozzle in a receiving aperture 38; an annular outer collar substantially surrounding the nozzle body 32; and a coil spring or other suitable biasing assembly surrounding the annular collar. In this embodiment, the outer collar includes an upper collar portion 36a and a lower collar portion 36b. The lower collar portion 36b terminates in a tapered end 36c having a substantially flat end wall 36d extending in a plane substantially perpendicular to the longitudinal axis of the nozzle. The nozzle body 32 and the collar portions are generally annular in form, but they include various additional structural features, such as a tapered end, to allow for corresponding functions as further described below.

[0089] In this non-limiting example, the collar upper portion 36a is rigidly connected to the nozzle body 32 so that the collar upper portion 36a and the nozzle body 32 move together. In contrast, the collar lower portion 36b, which includes the tapered end 36c, is configured to be slidably (or telescopically) movable relative to the nozzle body 32 in the longitudinal direction (the direction of the main longitudinal axis of the nozzle body). Thus, the nozzle 31 is configured to move between a body retracted position and a body extended position, as will be described in more detail below. In other embodiments not shown here, the collar upper portion 36a is configured to be slidably movable relative to the nozzle body 32.

[0090] The pick-up nozzle may be connected, inserted or otherwise attached to one end of the robotic arm 30. The central hole 33 of the pick-up nozzle may be selectively connected to a vacuum source (e.g., a vacuum or underpressure generator (not shown)) or a pressure source so that the gemstone 90 may be held on the receiving orifice 38 of the pick-up nozzle by negative pressure. Negative pressure is lower than the surrounding atmospheric pressure.

[0091] In one embodiment, the receiving aperture 38 defines a chamfered or outwardly angled surface (v-shaped surface, such as Figure 5 ), which is configured to align with or substantially correspond to the bottom point angle of a cut and polished gemstone. The matching shapes create a sealed connection and avoid or reduce a leak path for air, thereby improving the retention of the nozzle.

[0092] Return to reference Figure 5, the tapered end 36c of the lower collar portion 36b defines a protruding shoulder 36e at the distal end of the flat end wall 36d. Shoulder 36e provides a flat annular surface to which one end of a biasing assembly (in this example, a coil spring) can be connected or attached. The other end of the biasing assembly is attached or attached to a shoulder 36f defined by the upper collar portion 36a. In the retracted position, the spring holds the upper collar portion 36a and the lower collar portion 36b at a distance relative to each other, such as Figure 5 The nozzle body 32 is received within the collar upper portion 36a.

[0093] In the retracted position of the nozzle 31, the outer annular collar lower portion 36b, in particular the tapered end 36c tapering inwardly from the shoulder 36e, is configured to extend vertically below or vertically beyond the orifice 38, so that the orifice 38 is substantially surrounded by the collar lower portion 36b and the tapered end 36c in the radial direction. Therefore, any gemstone 90 retained on the nozzle orifice 38 via the negative pressure or vacuum applied to the orifice 38 through the hole 33 is also substantially surrounded by the tapered end 36c. In other words, the flat end wall 36d of the tapered end 36c extends longitudinally beyond the orifice 38 in the retracted position.

[0094] Now refer to Figure 6a and Figure 6b An example of using the nozzle 31 to dispense the gemstone 90 held thereon will be described. In particular, the movement of the nozzle 31 between the above-mentioned retracted position and the extended position will be described.

[0095] In a first actuation step performed by a controller (not shown), the lower end (tapered end 36c) of the nozzle 31 is brought into contact with or rests on a dispensing surface, such as, for example, the movable surface 20 (not shown here for clarity). In some embodiments, the flat end wall 36d of the tapered end 36c is configured to contact the dispensing surface. In some examples, the flat end wall 36d is configured to minimize the nozzle footprint when picking up and / or dispensing gemstones. It will be understood that in the retracted position of the nozzle 31, the gemstone 90 retained on the nozzle orifice 38 does not contact the surface (not shown here for clarity), but is instead retained a distance above the surface. In one example, the distance between the lowest point of the gemstone and the surface is approximately 0.5 mm. In this example, the longitudinal distance between the flat end wall 36d and the lowest point of the orifice 38 is defined as the distance D1, the first distance, as Figure 6a Since the flat end wall 36d of the tapered end 36c contacts the dispensing surface, the distance between the lowest point of the orifice 38 and the surface is also substantially D1.

[0096] exist Figure 6aIn the retracted position shown, the jewel 90 resting on the orifice 38 is thus enclosed in the space or volume formed by the annular wall of the conical end 36c and the dispensing surface, the flat end wall 36d of the conical end 36c being in contact with the dispensing surface.

[0097] However, the conical end 36c and / or the flat end wall 36d are preferably not in sealing contact with the surface. Air can flow between the interior and exterior of the lower collar 36b. A pressure differential between the interior and exterior of the lower collar 36b can be provided by a leakage path between the nozzle body 32 and the collar, and / or can be the result of an orifice provided in the lower collar 36b.

[0098] As Figure 6a shown, in the retracted position of the nozzle 31, the flat end wall 36d of the conical end 36c of the lower collar 36b contacts the dispensing surface after the first actuation step. An uncompressed helical spring located between the upper shoulder and the lower shoulder maintains a vertical gap or space between the upper collar 36a and the lower collar 36b. Thus, the conical end 36c extends beyond the nozzle orifice 38.

[0099] As Figure 6b shown, in the second actuation step, the nozzle 31 is then actuated or controlled by the controller to move further towards a surface (not shown here for clarity) extending in the direction indicated by arrow A. This downward movement applies a longitudinal force on the helical spring via the upper shoulder 36f, causing the spring to compress and closing or reducing the gap between the upper collar 36a and the lower collar 36b. Since the lower collar 36b is already in contact with the surface (not shown), the upper collar 36a moves substantially in the direction A together with the nozzle body 32 towards the lower collar 36b. In other words, as the nozzle body 32 moves in the direction A towards the extending surface, the lower collar 36b and its conical end 36c slide in the direction B above the nozzle body 32 including the orifice 38.

[0100] As Figure 6b shown, the nozzle orifice 38 and the jewel 90 resting thereon move further towards the dispensing surface (not shown for clarity). In other words, the nozzle 31 moves from the retracted position to the extended position. In this specific case, "retracted" and "extended" refer to the longitudinal position of the nozzle body 32 relative to the lower part of the outer collar 32b. As described above, in the retracted position, there may be a distance D1 between the lowest point of the orifice 38 and the flat end wall 36d of the conical end 36c. After the nozzle 31 has moved to the extended position, this distance is reduced to a second distance D2, as Figure 6c shown, where D2 < D1. The term "retracted" may also refer to the uncompressed position of the nozzle, and the term "extended" may refer to the compressed position of the nozzle.

[0101] However, the gemstone 90 is still not in direct contact with the surface while being held on the pick-up nozzle. Figure 6c As shown, maintaining a vertical gap G between the gemstone and the surface prevents the gemstone from sticking to the nozzle orifice 38 during the dispensing operation. Of course, the extent of this gap G will depend on the size of the gemstone held on the nozzle orifice, and generally the smaller the gemstone, the greater the gap and the greater the engagement of the gemstone with the nozzle orifice. As mentioned above, small gemstones can generate static electricity during handling / processing, which can cause the gemstone to become prone to unpredictable behavior and / or "stick" to the surface.

[0102] In some examples, depending on the size of the gemstone and the configuration of the aperture walls, distance D2 and gap G are substantially the same.

[0103] In one embodiment, the gap G is maintained by providing a stopper inside the upper or lower collar portion. Alternatively or additionally, the gap G is maintained and determined by a threaded member (not shown) that allows adjustment of the longitudinal space between the upper and lower collar portions, or by abutment of the upper and lower collar portions as the biasing member is compressed. In some examples, the gap G is maintained at about 0.25 mm by the upper surface of the lower collar portion and the lower surface of the upper collar portion.

[0104] Now refer to Figure 6b and Figure 6c , after the second actuation step, the gemstone 90 is held by the nozzle aperture 38 within the aperture wall, slightly above the movable surface 20 and inside the tapered end 36c of the collar lower portion 36b. The flat end wall 36d of the tapered end 36c of the collar is held firmly against the movable surface 20 so that the gemstone 90 cannot pass therethrough. The gemstone 90 can now be removed from the pick-up nozzle, for example, by using positive pressure to blow the gemstone 90 out of the receiving aperture 38 and onto the movable surface 20 below. The positive pressure in the form of "suction" air can be supplied via the central hole of the nozzle 31. The positive pressure is higher than the surrounding atmospheric pressure.

[0105] Thus, the final position of the dispensed gemstone on the dispensing surface is controlled or constrained by the inner diameter of the flat end wall 36d of the tapered end 36c of the collar. In one embodiment, the inner diameter (or maximum dimension if the collar is not annular) of the end wall 36d is about 2 mm. The gemstone 90 can be dispensed by "sucking" air applied by positive pressure to disengage the gemstone 90 from the nozzle 31 or blow the gemstone 90 away from the nozzle 31, but any lateral movement of the gemstone on the movable surface 20 is constrained to the area of ​​the movable surface 20 corresponding to the inner diameter (or maximum dimension) of the end wall 36d. This is true even in the case where the gemstone bounces or otherwise moves after first contacting the movable surface 20 before coming to rest. However, in some embodiments, the gap G is configured so that the gemstone 90 maintains the orientation maintained by the nozzle 31 after resting on the dispensing surface. This allows the gemstone 90 to be accurately placed on the movable (dispensing) surface 20 even in the case where the gemstone 90 may be electrostatically charged as described above.

[0106] After the gemstone 90 has been dispensed from the nozzle 31, the controller (not shown) actuates or controls the nozzle 31 to move away from the movable surface 20 in a third actuation step, leaving the gemstone 90 behind. As the downward force on the nozzle body 32 is removed, the nozzle 31 moves from the extended position back to the retracted position as the coil spring expands to an uncompressed position. The collar upper portion 36a moves away from the collar lower portion 36b, and the nozzle body 32 retracts by sliding longitudinally relative to the tapered end 36c so that the tapered end 36c again extends beyond the nozzle orifice 38.

[0107] It will be appreciated that, although the above describes the dispensing of a gemstone already held on the nozzle, similar steps apply when picking up a gemstone. The difference between picking up and placing (dispensing) is that, in picking up, a reduced pressure is provided through the nozzle so that the gemstone attaches and remains attached to the nozzle. In placing a gemstone, the nozzle is brought to its placement position and once there, a momentary positive air pressure is applied to the nozzle to "blow" the gemstone off the nozzle and onto the movable surface. In this regard, the lower collar prevents the positive air pressure from causing the gemstone to move too far from its intended position on the movable surface. The positive air pressure is stopped or cut off before the nozzle is retracted to avoid the gemstone being blown out of the inner periphery of the tapered end.

[0108] In one example, the total time period between picking up a first gemstone with the nozzle, dispensing the gemstone onto the movable surface, and returning to the collection position (light table) to pick up a second gemstone is about 1 second. The total time period between picking up the first gemstone and dispensing (placing) the first gemstone onto the movable surface is about 0.5 seconds.

[0109] In one embodiment, the nozzle body is provided with a protrusion 36g which is configured to cooperate with a corresponding recess 36h on the interior of the tapered end 36c. The protrusion 36g and the recess 36h cooperate to prevent the nozzle body 32 from being retracted too far within the collar lower portion 36b. Figure 6c The cooperation of the protrusion 36g and the recess 36h is shown in the cross section shown.

[0110] In one embodiment, instead of or in addition to the coil spring, an alternative biasing assembly is provided. For example, a resiliently deformable material may be used.

[0111] In certain embodiments, a nozzle for picking up and dispensing gemstones includes: a body defining a central bore and terminating in an orifice configured to receive a gemstone; a collar substantially surrounding the body, wherein the body is movable between a retracted position and an extended position relative to at least a portion of the collar; wherein, in the retracted position, the collar extends beyond the orifice in the direction of a main longitudinal axis of the body by a first distance; and in the extended position, the collar extends beyond the orifice in the direction of the main longitudinal axis of the body by a second distance; wherein the first distance is greater than the second distance.

[0112] The body is telescopically connected to the collar. The nozzle may be configured to pick up and dispense gemstones having a maximum size of 1 mm, preferably between 0.5 mm and 1 mm. The central hole may be configured to be connected to a pressure source in use. The pressure source may be configured to apply negative pressure or positive pressure to the orifice. The nozzle may be biased back to a retracted position by a biasing element, wherein the biasing element is one of a spring, a coil spring, and an elastically deformable material. The body and the collar may be substantially annular. The collar may include an upper collar portion and a lower collar portion. The upper collar portion and the lower collar portion may be longitudinally separated by a coil spring. The upper collar portion may be configured to move with the nozzle body, and the lower collar portion may be configured to be movable relative to the nozzle body. The lower collar portion may terminate in a tapered end. The lower collar portion may terminate in a substantially flat end wall. The orifice may define an outwardly facing surface or a set of surfaces suitable for receiving a gemstone. The gemstone may be a cut gemstone. The surface defined by the orifice may have a substantially v-shaped cross section, and optionally, the angle of the v-shaped cross section may match the angle between the outer surfaces of the cut gemstone. The nozzle may be attached to the robotic arm. The robotic arm and / or the nozzle attached thereto may be actuated by a controller.

[0113] In certain embodiments, a method for dispensing gemstones includes providing a nozzle including a nozzle body defining a central hole extending therethrough and terminating in an orifice, the body being substantially surrounded by a collar and slidably movable relative to at least a portion of the collar between a retracted position and an extended position; wherein, in the retracted position, the collar extends beyond the orifice by a first distance; and, in the extended position, the collar extends beyond the orifice by a second distance; wherein the first distance is greater than the second distance, and wherein, in both the retracted and extended positions, the orifice is surrounded by the collar; receiving a gemstone to be dispensed at the orifice; applying negative pressure to the orifice to hold the gemstone at the orifice; with the nozzle in the retracted position, bringing the collar into contact with a surface onto which the gemstone is to be dispensed; actuating the nozzle to the extended position; applying positive pressure to the orifice to dispense the gemstone onto the surface; and actuating the nozzle to the retracted position.

[0114] The method may include connecting the central hole to a pressure source to apply negative or positive pressure to the orifice. The method may include one or more of the following: biasing the nozzle to a retracted position; moving the upper collar portion with the nozzle body and moving the lower collar portion relative to the nozzle body; controlling the final position of the gemstone on the surface by the inner diameter of the tapered end of the collar; contacting the collar with the surface on which the gemstone is to be dispensed with the nozzle in the retracted position, and actuating the nozzle to an extended position while maintaining a vertical gap between the gemstone and the surface; orienting the gemstone before receiving it on the orifice, and maintaining the same orientation while dispensing the gemstone on the surface; attaching the nozzle to an actuation mechanism, and controlling the actuation mechanism to move the nozzle from a collection position for receiving the gemstone to a dispensing position for dispensing the gemstone on the surface; surrounding the gemstone with the collar while applying positive pressure. Applying positive pressure to the orifice to dispense the gemstone on the surface may include stopping applying the positive pressure before actuating the nozzle to the retracted position.

[0115] exist Figure 5 , Figure 6 and Figure 7 In the illustrated embodiment, as described above, individual gemstones can be accurately placed (e.g., within 2 mm) onto the upper surface of the movable surface in the correct orientation (e.g., table-down orientation). As described above, the movable surface 20 is stationary during placement of the stone, but once the stone has been placed, the movable surface 20 begins to move again.

[0116] In one embodiment, by incrementing the movable surface by a very small amount before each gemstone screening stroke begins, any wear caused by repeated contact between the movable surface and the pick-up nozzle collar is reduced or eliminated.

[0117] Once positioned on the movable surface by the robotic arm, the gemstone remains in that position as it is transported to one or more measurement locations by the movable surface. In other words, the gemstone does not change its position or orientation between being placed on the movable surface by the robotic arm and being dispensed at one or more dispensing locations. This is true even if the movable surface is intermittently moved between placement and dispensing.

[0118] Return to reference Figure 1 In an embodiment of the present invention, the apparatus comprises a first and a second measurement position 40a, 40b. In one embodiment, the first measurement position comprises a luminescence measurement unit and the second measurement position comprises a photoluminescence (PL) measurement unit. It will be appreciated that in other embodiments, further measurements may be obtained at one or more measurement positions. Similarly, only one measurement position may be provided and one or more measurements of the stone may be obtained at this one measurement position. Alternatively, the same measurement may be obtained at the first and second measurement positions, so the measurements may be repeated. It will be appreciated that in other examples, the first measurement position comprises a PL measurement unit and the second measurement position comprises a luminescence measurement unit. Alternative / additional measurement units are conceivable.

[0119] Measurements of a gemstone may be obtained by illuminating the gemstone, for example with ultraviolet light or other radiation, to obtain luminescence from the stone. The light may be provided by a laser, LED or other excitation source, and the light emitted by the gemstone is detected by a detector known to the skilled person to obtain a photoluminescence (PL) spectrum. Although it may be desirable to increase the illumination spot size and / or detection area to ensure that the gemstone is fully and / or properly illuminated during the measurement, such an increase in the spot size and / or detection area may reduce the sensitivity of the measurement by increasing the signal-to-noise ratio, as the area surrounding the stone will contribute noise through scattering of light without increasing the signal. Therefore, in one embodiment, an illumination arrangement is provided at one or both measurement locations, wherein the conventional angle of incidence of (for example) the PL illumination laser is reduced and shallower. It will be understood that the shallower illumination angles are not limited to PL measurements, but may be used for other measurements of gemstones.

[0120] Figure 8b A modified shallow illumination arrangement is shown in Figure 8a The conventional illumination arrangement shown in is used for comparison. Figure 8a In the embodiment, a gemstone 90 supported on a movable surface 20 at a measurement position 40 is illuminated by a light beam 42 at a predetermined angle of incidence C. In one embodiment, the angle C may be about 49 degrees from the horizontal plane. Figure 8aAs shown in the enlarged portion of FIG. 1 , the illumination spot size is therefore relatively small, requiring the gemstone to be placed highly accurately on the movable surface to ensure complete and / or correct illumination and collection, with the collection optics being perpendicular to the movable surface. Failure to place the gemstone so that it is within the illumination spot on the movable surface can result in inaccurate measurements. This is particularly problematic for very small melee diamonds (e.g., 0.1 to 0.3 point stones) that are easily missed by the illumination beam. In the event that a particular gemstone is not fully illuminated by the beam, measurements of the gemstone's properties may be inaccurate or unobtainable.

[0121] exist Figure 8b In one embodiment, the modified illumination arrangement has a reduced predetermined angle of incidence D, where C>D. In one embodiment, the angle D is about 10 degrees from the horizontal plane defined by the movable surface. Figure 8b As shown in the enlarged part, Figure 8a The illumination spot size of beam 42' is therefore larger in comparison. Therefore, the shallower angle of incidence results in a reduced sensitivity to the radial position of the gemstone on the movable surface. In addition, the intensity of the illumination beam incident on the gemstone is not significantly reduced, unlike the intensity of a beam expanded by a conventional beam expander to achieve the same illuminated area in the horizontal plane without changing the angle of incidence.

[0122] As described above, the radial position of the gemstone on the movable surface, measured, for example, as the distance between the stone and the center of the movable surface, can be controlled by the inner diameter of the pick-up nozzle collar on the robotic arm. However, it may also be necessary to control the circumferential position (e.g., distance along the movable surface) in order to ensure correct illumination at one or more measurement locations. Again, this is particularly problematic for very small melee diamonds (e.g., 0.1 to 0.3 point stones).

[0123] In one embodiment, the reduction in sensitivity of the circumferential position of the gemstone is achieved by slowly moving the gemstone through the detection area at one or more measurement locations before accelerating the movable surface to normal speed during the next increment of the movable surface. In other words, the movable surface can be operated at least at a first speed and a lower second speed. In this way, even if the gemstone is not initially circumferentially located within the illumination spot as it approaches the measurement location, the gemstone can subsequently pass through the illumination spot as it slowly moves through the measurement location, the radial position of the stone having been controlled by the pick-up nozzle as described above. This reduction in speed has a negligible effect on the overall speed and / or throughput of the device.

[0124] Using the above example methods, which may be applied at one or two measurement locations, the desired measurement sensitivity may be maintained while allowing for reasonable tolerances in the gemstone position. This in turn enables feasible commissioning and operating tolerances to be employed in an automated arm (robot) setup.

[0125] Return to reference Figure 1 In an embodiment of the present invention, at a first measurement position 40a, the luminescence measurement unit includes a source of electromagnetic radiation having a wavelength of substantially 225 nanometers (nm) or less (provided by an ultraviolet or UV lamp, a laser, or other light source) for exciting the gemstone and a light detection device or camera for capturing any visible light emitted by the gemstone upon excitation by the electromagnetic radiation. The operation of the UV lamp and the camera is synchronized by the controller taking into account any offset values ​​applicable to the camera. The camera can capture light (e.g., fluorescence) emitted by the gemstone during the excitation. The controller can also selectively configure a delay to the camera to enable the camera to capture light during a time window starting after the end of the excitation. Thus, the camera can capture phosphorescence as well as fluorescence.

[0126] Fluorescence is typically only emitted during UV excitation of the gemstone. Any fluorescence generated during the excitation will decay very quickly once the excitation ends. Phosphorescence, on the other hand, is a type of luminescence that remains once the excitation is removed, but then decays over a longer time scale. Phosphorescence may persist for some time after the excitation ends, or it may decay within a few milliseconds of the end of the excitation pulse. The process of delaying the capture of visible light until the excitation pulse ends and any fluorescence decays ensures that the fluorescence is "gated" and does not obscure any phosphorescence emitted after the end of the excitation pulse. The end of the time window for capturing visible light emitted by the gemstone can also be carefully selected to select the decay time of the captured fluorescence and / or phosphorescence. In this way, the device can capture visible light emissions that might otherwise be missed. Other methods for improving the signal-to-noise ratio may be included, such as a lock-in amplifier or various filters.

[0127] exist Figure 1 In an embodiment of the present invention, at a first measurement location 40a, a gemstone is illuminated with a plurality of excitation pulses of electromagnetic radiation, and during and / or after each excitation pulse, light emitted by the gemstone in at least one time window having a predetermined time relationship with respect to the excitation pulse is detected to obtain luminescence data. The or each time window may be selected to include luminescence having a decay time characteristic of one or more "markers" characterized by a particular luminescence wavelength and decay time. The decay time may be defined as the time taken for a number of excited molecules to decay to 1 / e or 36.8%. The luminescence data associated with all pulses may be combined and then analyzed at a processor (not shown) to establish the presence or absence of one or more markers.

[0128] Non-limiting examples of specific markings that may be used when identifying a gemstone at the first measurement location 40a are shown in Table 1.

[0129]

[0130] Table 1

[0131] exist Figure 1 In the embodiment of the present invention, the gemstone at the second measurement position 40b is subjected to laser excitation at about 450nm with a 3mm diameter beam at an angle of about 10° relative to the horizontal plane. PL detection is performed on a 3mm diameter measurement area using a micro-spectrometer at 0° relative to the vertical plane using a single lens system.

[0132] Once the PL spectrum of the gemstone at the second measurement location 40b is acquired, it is sent to the controller and analyzed, for example using a suitable algorithm. A determination can be generated about the gemstone tested and the gemstone identified based on the presence of Raman lines and / or detection of Ni related PL features.

[0133] There is a chromatin at about 1332 cm -1 The sharp single Raman line centered at is an indication that the gemstone being tested contains diamond material and is therefore not a simulant, so the measurement will indicate that the gemstone is not composed of a substance other than diamond (e.g., cubic zirconia). The presence of a Ni-related PL feature at about 787nm in the spectrum in the absence of a stronger 793nm feature is an indication that the gemstone being tested is natural diamond and not synthetic diamond. -1 The presence of a sharp single Raman line at 787 nm and the presence of a Ni-related PL feature at 793 nm but not at 787 nm are indicators that the stone being tested is natural diamond. -1 The absence of Raman lines is an indication that the gemstone being tested is not diamond.

[0134] A determination as to whether a gemstone at the second measurement location 40b is natural may be made based on the results for that gemstone received from both the first and second measurement locations 40a, 40b. Thus, this determination may not be made until the gemstone has passed both measurement locations 40a, 40b. It will be appreciated that where it is determined at the first measurement location that a particular stone should be referenced for further testing, the measurement obtained at the second measurement location may provide that further testing. Thus, the number of gemstones in a package that require further testing and / or analysis using separate equipment may be reduced.

[0135] Once a gemstone has passed through one or more measurement locations, it is dispensed or removed from the movable surface at one of the one or more dispensing locations. In one embodiment, the dispensing is performed based on measurements obtained at the one or more measurement locations. One or more processors at the one or more measurement locations send a signal to the controller to activate an appropriate dispensing mechanism at the one or more dispensing locations based on the analysis of the measurements performed by the processor.

[0136] Fig. 9An embodiment is shown in which each dispensing location 70 includes a dispensing mechanism in the form of a rotating wheel 75 and a dispensing bin 80 or container. In this embodiment, the rotating wheel 75, which may include a closed-cell foam material, is arranged to rotate about a horizontal axis located above the movable surface 20. The rotating wheel 75 includes one or more (e.g., 5) teeth arranged around the periphery. Each tooth includes a leading portion and a trailing portion, the leading portion extending further from the center of the rotating wheel 75 than the trailing portion.

[0137] In the embodiment shown here, a motor (not shown) is configured to rotate the wheel 75, and a sensor (which may be a light curtain, not shown) is configured to identify when one of the teeth is in a predetermined (e.g., home) position. The wheel 75 is arranged so that a gap is defined between the movable surface 20 and the wheel 75 when the wheel 75 is in the home position. As the wheel 75 rotates away from the home position, one of the teeth contacts the gemstone to be dispensed and pushes the gemstone off the movable surface and into a predetermined dispensing bin 80. The wheel may be further arranged so that as the wheel rotates away from the home position, one of the teeth contacts the horizontal movable surface 20 and pushes the gemstone off the movable surface 20.

[0138] As mentioned above, the above-described wheel may be particularly suitable for very small gemstones because each gemstone may be gently swept away from the movable surface rather than being "flicked". This may be particularly advantageous for very small stones (e.g., 0.1 to 0.3 point stones) due to the electrostatic charge that may be induced on such small stones and their tendency to behave unpredictably.

[0139] In one non-limiting example, there are five dispensing bins, each associated with a dispensing mechanism such as the above-mentioned rotating wheel. The dispensing bins are designated as follows: non-diamond (e.g., simulants such as cubic zirconia); synthetic; pass / natural; reference (for gemstones whose properties have not yet been conclusively determined); and clear (for use when it is desired to quickly empty the device of gemstones).

[0140] An exemplary method of sorting gemstones, optionally small grain diamonds as described above, is shown in Fig.10 In this example, the method includes: receiving one or more gemstones at a collection location; determining at the collection location that one of the one or more gemstones is correctly oriented; transferring the oriented gemstone from the collection location to a movable surface using a robotic arm; transporting the gemstone to one or more measurement locations on the movable surface; measuring one or more properties of the gemstone at the one or more measurement locations while the gemstone is supported on the movable surface; and sorting the gemstone based on the measured one or more properties.

[0141] In a specific non-limiting example, the sorting of gemstones is performed as follows. A bag of stones is distributed into a hopper. Then, the hopper is vibrated, for example using a device such as an Asyril Asycube oscillator, so that the stones travel along the inner surface of the hopper toward the baffle. The gemstone passes the baffle in a controlled manner and falls onto the surface of the light table and arrives at a collection position. Once in the collection position, the gemstone is imaged to determine its orientation. Gems that are correctly oriented (usually in a table-down orientation) are designated to be picked up by an automatic arm. Gems that are not correctly oriented (usually not in a table-down orientation) are reoriented by the vibration of the light table. The reoriented gemstone is imaged again, and its orientation is further determined. Once it is determined that the reoriented stone is in a table-down orientation, the stone is designated to be picked up by an automatic arm. In one example, once an image of the gemstone on the light table has been obtained, the controller controls the automatic arm to transfer all correctly oriented stones to a movable surface, and then the light table is vibrated again and another image is obtained.

[0142] The automated arm includes a vacuum nozzle that enables a single gemstone to be held thereon. The arm is actuated to transfer the stone held on the nozzle to the movable surface where the stone is dispensed by applying positive pressure. The placement of the gemstone on the surface of the movable surface is controlled by an annular collar surrounding the vacuum nozzle. The movable surface is stationary while the gemstone exits the nozzle to be dispensed onto the movable surface.

[0143] The gemstone, still correctly oriented (usually table-side down), is transported on the movable surface to a first measurement position. Here, the movable surface is stopped while a first measurement of the stone is obtained. The gemstone is then transported further on the movable surface to a second measurement position. Here, the speed of the movable disc is reduced so that the gemstone slowly passes the second measurement position while a second measurement of the stone is obtained. The stone is illuminated by a beam at a shallow angle of about 10 degrees from the horizontal at the second measurement position.

[0144] Once the stone has passed the second measuring position, the movable surface is accelerated back to normal transport speed and the gemstone is transported to the dispensing position where it leaves the movable surface to be dispensed into a specific dispensing bin based on the measurements obtained at the first and second measuring positions.

[0145] At any one moment, multiple stones may be present on the movable surface: for example, the robotic arm places one stone on the movable surface; another stone is measured at a first measurement location, another stone is measured (or is about to be measured or has just been measured) at a second measurement location, and another stone is dispensed into a dispensing bin.

[0146] The skilled person will appreciate that various modifications may be made to the above embodiments without departing from the scope set forth in the following claims. For example, the embodiments described herein may be combined, and one or more features of one embodiment may be replaced with one or more features of another embodiment, but this is not limiting.

Claims

1. A method for sorting gemstones, the method comprising: receiving one or more gemstones at a collection location; determining, at the collection location, that a gemstone of the one or more gemstones is properly oriented; Use an automated arm to transfer the properly oriented gemstones from the collection location to a movable surface; transporting the gemstone on the movable surface to one or more measurement locations; measuring one or more properties of the gemstone at the one or more measurement locations while the gemstone is supported on the moveable surface; as well as The gemstones are sorted based on the one or more properties measured.

2. The method according to claim 1, wherein: Gems are generally between 0.1 and 0.3 points.

3. The method according to claim 1, wherein: The movable surface is a rotatable disc.

4. The method according to claim 3, wherein: The transfer includes: Stop the rotatable disc; distributing gemstones onto the surface of a rotatable disc; and The rotatable disc is rotated by a predetermined angle.

5. The method according to claim 4, wherein: The predetermined angle is 9 degrees.

6. The method according to claim 1, comprising: While the movable surface is stationary, the properly oriented first gemstone is transferred to the movable surface while one or more properties of the second gemstone are measured at at least one of the one or more measurement locations.

7. The method according to claim 6, comprising: While the movable surface is stationary, a properly oriented first gemstone is transferred onto the movable surface, one or more properties of a second gemstone are simultaneously measured at at least one of the one or more measurement locations, and a third gemstone is simultaneously dispensed off the movable surface.

8. The method according to any one of claims 1 to 7, comprising: One or more properties of the first gemstone are measured at at least one of the one or more measurement locations while the second gemstone is transported on the movable surface, wherein the movable surface is non-stationary.

9. The method according to any one of claims 1 to 7, wherein: One of the at least one measuring location comprises a luminescence measurement unit.

10. The method according to any one of claims 1 to 7, wherein: One of the at least one measuring locations comprises a photoluminescence measuring cell.

11. The method according to any one of claims 1 to 7, wherein: Measuring at least one of the one or more properties of the gemstone comprises illuminating the gemstone with a light beam having an angle of incidence of substantially 10 degrees measured from a horizontal plane.

12. The method according to claim 11, comprising: During measurement the gemstone is transported past the measurement location.

13. The method according to any one of claims 1 to 7, wherein: Each of the one or more gemstones is sorted based on the one or more measurements identifying the gemstone as natural or synthetic.

14. The method according to any one of claims 1 to 7, comprising: The movable surface is moved at a first speed and a second speed, wherein the second speed is less than the first speed.

15. The method according to any one of claims 1 to 7, comprising: The gemstones are sorted by further transporting the gemstones to a dispensing location and dispensing the gemstones off the movable surface based on the one or more properties of the gemstones measured.

16. The method according to any one of claims 1 to 7, comprising: One or more gemstones are received from the hopper at a collection location and flow of the one or more gemstones is controlled through the hopper to the collection location.

17. The method according to claim 16, comprising: The flow of the one or more gemstones is controlled via an end hopper wall defining an orifice at a bottom thereof.

18. The method according to claim 16, comprising: A hopper is provided having at least one substantially curved inner surface.

19. The method according to claim 1, comprising: An image of one of the one or more gemstones at the collection location is obtained, and the obtained image is analyzed to determine the orientation of the gemstone.

20. The method according to claim 19, wherein: The orientation is determined to be correct, thereby designating the imaged gemstone for transfer to the removable surface.

21. The method according to claim 19, wherein: When the orientation is determined to be incorrect, the collection location is vibrated to reorient the imaged gemstone.

22. A method according to any one of claims 19 to 21, comprising: Once all gemstones determined to be correctly oriented at the collecting location have been transferred from the collecting location to the movable surface, the collecting location is vibrated.

23. The method according to any one of claims 19 to 21, wherein: When the imaged gemstone is determined to be in a table-down orientation, the orientation is determined to be correct.

24. The method according to any one of claims 1 to 7 and claims 19 to 21, comprising: A vacuum nozzle is provided at one end of the robotic arm, negative pressure is supplied to the orifice of the vacuum nozzle for picking up individual gemstones using the orifice, and positive pressure is supplied to the vacuum nozzle for dispensing the gemstones out of the orifice onto the movable surface.

25. The method according to claim 24, comprising: The vacuum nozzle is provided with an annular collar which substantially surrounds the orifice while the gemstone is dispensed out of the orifice.

26. The method according to any one of claims 1 to 7 and claims 19 to 21, comprising: measuring one or more properties of the gemstone at the one or more measurement locations while the movable surface is stationary; as well as One or more properties of the gemstone are measured at the one or more measurement locations while the movable surface is not stationary.

27. An apparatus for sorting gemstones, comprising: a collection location configured to receive one or more gemstones; an image capture device configured to obtain one or more images of the one or more gemstones at a collection location; a processor configured to analyze the one or more images and determine whether one or more of the one or more gemstones are properly oriented; an automated arm configured to transfer the properly oriented gemstone from the collection location to the movable surface; the movable surface being configured to transport the gemstone to one or more measurement locations; as well as The one or more measurement locations are configured to measure one or more properties of the gemstone while the gemstone is supported on the moveable surface.

28. The apparatus of claim 27, wherein: Gems are generally between 0.1 and 0.3 points.

29. The apparatus of claim 27, wherein: The movable surface is a rotatable disc.

30. The apparatus of claim 29, further comprising: A controller is configured to incrementally move the rotatable disk by a predetermined angle.

31. The apparatus of claim 30, wherein the predetermined angle is 9 degrees.

32. The apparatus of claim 27, wherein: The controller is configured to control the movable surface to remain stationary during the transfer of the gemstone onto the movable surface.

33. Apparatus according to any one of claims 27 to 32, wherein: The controller is configured to control the movable surface to be non-stationary during measurement of the one or more properties of the gemstone.

34. Apparatus according to any one of claims 27 to 32, wherein: One of the at least one measurement location includes one of a luminescence measurement unit and a photoluminescence measurement unit.

35. Apparatus according to any one of claims 27 to 32, further comprising an illumination arrangement at one or more measurement positions, the illumination arrangement being configured to illuminate a gemstone supported on the moveable surface at a predetermined illumination angle.

36. The apparatus of claim 34, wherein: The illumination angle measured from the horizontal plane is 10 degrees.

37. Apparatus according to any one of claims 27 to 32, wherein: The movable surface is controlled to move at a first speed and a second, lower speed, the movable surface being configured to move at the second, lower speed as the gemstone is transported past one of the one or more measurement locations.

38. Apparatus according to any one of claims 27 to 32, comprising one or more dispensing locations, each dispensing location comprising a dispensing mechanism and a dispensing bin.

39. Apparatus according to any one of claims 27 to 32, comprising a hopper arranged to provide one or more gemstones to a collection location.

40. Apparatus according to any one of claims 27 to 32, wherein: The hopper is provided with an end wall defining an orifice at a bottom thereof, and wherein the hopper is configured to control a flow of gemstones via the orifice to a collection location.

41. The apparatus of claim 39, wherein: The body of the hopper slopes towards the orifice at an angle of 3 degrees measured from horizontal, and / or wherein the end wall slopes inwardly at an angle of 75 degrees measured from horizontal.

42. Apparatus according to any one of claims 27 to 32, comprising a vibration mechanism arranged to vibrate the collection location to correctly orient one or more gemstones at the collection location.

43. Apparatus according to any one of claims 27 to 32, comprising a vacuum nozzle connected to the end of the robotic arm, the vacuum nozzle comprising an aperture for receiving a gemstone and an annular collar configured to surround the aperture.

Images