The present invention relates generally to the field of gemstone evaluation systems. More particularly, the present invention relates to a gemstone evaluation system with the added feature of automatic centering of a gemstone and the addition of a narrow band spectrophotometer to determine the authenticity of the gemstone.
The commercial value of a gemstone depends on a number of factors, including weight, cut, clarity, color, and, perhaps most importantly, the authenticity of the gemstone. Traditionally, evaluating those and other such characteristics was the job of highly trained specialists, known as “graduate gemologists.” Recently, a number of computer controlled machines have been developed to perform many of the same functions as graduate gemologists. The machines are more consistent and precise when it comes to measuring minute details and features present in gemstones. In particular, the machines are used to evaluate differences in color that are imperceptible to even the highly trained eye of a graduate gemologist. One such machine is described in U.S. Pat. No. 5,615,005, which is incorporated herein by reference in its entirety for all purposes.
Machines like the one described in U.S. Pat. No. 5,615,005 typically include a light source, optical band pass filter, camera or wide band spectrophotometer, and analysis chamber. An operator places the gemstone in the observation chamber, and light from the light source is sent through the band pass filter such that a specific wavelength of light illuminates the gemstone. The light source may also be manipulated so that the beam of light illuminates the gemstone from varying angles, thus performing the same test as a gemologist would perform manually. The cameras that are currently used in gemstone evaluation machines are typically Charged Coupled Device (CCD) cameras or wide band spectrophotometers. These cameras are an improvement over the human eye, but cannot detect the difference between a diamond or a cubic zirconium, for example. Rather, the cameras currently used in gemstone evaluation machines can only determine where the gemstone falls on a color/clarity scale. To determine whether a gemstone such as a diamond is authentic (not man or machine made), a separate test must be performed, often in a separate lab. The separate test may involve narrow-band spectrophotometry, which is targeted to a range of wavelengths known in the art, typically with a scanning band 1-3 nm wide.
The present invention relates to a gemstone positioning and analysis system for measuring characteristics of a gemstone that includes a cabinet having an analysis chamber adapted to receive the gemstone. The analysis chamber has upper and lower hemispherical portions with a mounting plate between the hemispherical portions. The hemispherical portions each have reflective inner surfaces. The lower hemispherical portion has an aperture at its lowermost point that is adapted to allow light to pass into the analysis chamber. The clear mounting plate includes a series of markings to facilitate centering the gemstone within the analysis chamber. An alignment device is included that has at least one linear pusher and is adapted to automatically center the gemstone at the centermost point of the clear mounting plate. A movable light source is adapted to illuminate the gemstone from a plurality of angles, and a camera is adapted to record images of the gemstone. The camera is further adapted to provide data to a computer system that analyzes the data and outputs the material characteristics of the gemstone.
The gemstone evaluation system of the present invention includes the automatic positioning of a gemstone and a narrow band spectrophotometer (“NBS”), which allows the machine to detect material characteristics of the gemstone such as whether it is natural or man-made. The automatic positioning function solves the problem of an operator inaccurately placing a gemstone on the observation plane, which can result in erroneous test results. The addition of an NBS also allows a user to simultaneously perform the tests of the current system and the additional tests that are now performed by a secondary process. Performing the tests together greatly decreases the likelihood of fraud or deception that, regrettably, is possible when the tests are performed separately, often in different labs. After the analysis is complete, a user is provided a report showing the characteristics of the gemstone, including the results of the narrow-band spectrophotometer analysis, along with a picture of the gemstone. Such a report virtually eliminates the opportunity for deception that currently exists.
It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom.
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The cabinet 12 contains a light source 14 and a control system 16. The control system 16 controls a light motion system 18. The cabinet 12 further includes an analysis chamber 20, and an annular light ring 22. The annular light ring 22 is mounted to a platform 24 moved by the light motion system 18. Light ring 22 may be illuminated in a variety of ways, but in the embodiment shown, light is conveyed from the light source 14 to the annular light ring 22 by means of a fiber optic connector 25.
Analysis chamber 20 is a two-piece unit including an upper hemispherical member 26 and a partial lower hemispherical member 28, forming a sphere, with a reflective coating on the inside of upper member 26 and lower member 28. A single entry/exit aperture 30 is formed in the lowest part of the lower member. The entry/exit aperture 30 is of adequate size to allow light to enter the analysis chamber 20, and for a CCD camera assembly 34 to be able to view the gemstone 46 in the analysis chamber 20, yet small enough that light is effectively reflected within the analysis chamber 20 to provide accurate test results. Centered in the chamber is a glass plate 32 on which a gemstone to be evaluated is placed tableside down. Tableside down orientation is preferred because currently gemstones are graded by refracted light through the table of the gemstone. Although glass is preferred, other clear, transparent materials may be used, in any supporting structure. Etched or otherwise marked onto the glass plate 32 is a pattern 33 that allows the system to accurately measure the size and location of the gemstone 46 at any given time. In the embodiment shown, the pattern 33 is a bulls-eye pattern, but any suitable pattern could be used without deviating from the invention. At the center of the pattern 33 is a center point 36.
The light motion system 18 is configured to move the annular light ring 22 such that as the platform 24 moves, the light from the annular light ring 22 illuminates a gemstone 46 from a range of angles. Gemstones are generally viewed by gemologists from multiple angles, relative to light sources, to obtain the quality and color of a gemstone. The multiple position light source provides the device with the same capabilities.
Directly below the annular light ring 22 is located a CCD camera assembly 34, which includes a fixed focal length lens 31, a band pass filter 37, and a CCD camera 39. The CCD camera assembly 34 is oriented to be aimed at the center of the analysis chamber 20. The centerlines of the analysis chamber 20, annular light ring 22, and CCD camera assembly 34 are intended to be common. The CCD camera assembly 34 is used to both analyze the quality and color of the gemstone 46, but is also used to accurately position the gemstone 46 such that the centerline of the gemstone 46 is also common with the centerlines of the analysis chamber 20, annular light ring 22, and CCD camera assembly 34.
An alignment device 40 is adapted to automatically align the gemstone with that common centerline, without the necessity of the operator locating that centerline and attempting to manually align the gemstone's centerline with it simply by hand placement of the gemstone. The alignment device 40 includes a pusher member 42, operated by a linear actuator 44, in turn connected to and controlled by the control system 16.
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Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.
This application is based on and claims priority from U.S. Provisional Patent Application No. 61/477,267 filed on Apr. 20, 2011, which is incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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61477267 | Apr 2011 | US |