阅读说明：本技术 一种钻石腰线观测仪及观测方法 (Diamond waistline observation instrument and observation method ) 是由 雷自力 于 2020-05-11 设计创作，主要内容包括：本发明公开了一种钻石腰线观测仪,包括支撑平台、成像调整系统、成像系统、钻石定位装置和钻石吸附旋转系统；成像系统包括显微镜头和与该显微镜头连接的相机,以用于拍摄显微镜中观察的钻石的腰线图片,显微镜头的轴线沿左右方向延伸；钻石定位装置包括手轮、凸轮轴、凸轮、配重块、滑动轴承、光杆和定位块,定位块的底部设置有用于让钻石的钻尖伸入该定位块的定位孔；钻石吸附旋转系统位于所述定位块的下方,钻石吸附旋转系统包括用于吸附钻石的台面的真空吸附装置和用于带动所述真空吸附装置转动的电机。本发明依据大量钻石的腰部成型的圆周分布特点,结合光学变倍成像原理、气动旋转吸附方法和图像处理技术,鉴定结果准确。(The invention discloses a diamond waist line observation instrument which comprises a supporting platform, an imaging adjusting system, an imaging system, a diamond positioning device and a diamond adsorption rotating system, wherein the imaging adjusting system is arranged on the supporting platform; the imaging system comprises a microscope lens and a camera connected with the microscope lens, and is used for shooting a waist line picture of the diamond observed in the microscope, and the axis of the microscope lens extends along the left-right direction; the diamond positioning device comprises a hand wheel, a cam shaft, a cam, a balancing weight, a sliding bearing, a polished rod and a positioning block, wherein the bottom of the positioning block is provided with a positioning hole for enabling a diamond drill point to extend into the positioning block; the diamond adsorbs the rotating system to be located the below of locating piece, diamond adsorbs the rotating system including the vacuum adsorption device who is used for adsorbing the lithodomous mesa and be used for driving vacuum adsorption device pivoted motor. According to the circumferential distribution characteristics of waist formation of a large number of diamonds, the identification result is accurate by combining the optical zoom imaging principle, the pneumatic rotary adsorption method and the image processing technology.)

1. The utility model provides a diamond stringcourse visulizer, its characterized in that includes supporting platform, formation of image adjustment system, imaging system, diamond positioner and diamond absorption rotating system, wherein:

the imaging adjusting system is arranged on the supporting platform, and the imaging system is arranged on the imaging adjusting system and is used for driving the imaging system to move left and right, front and back and up and down;

the imaging system comprises a microscope lens and a camera connected with the microscope lens, and is used for shooting a waist line picture of a diamond observed in the microscope, and the axis of the microscope lens extends along the left-right direction;

the diamond positioning device comprises a hand wheel, a cam shaft, a cam, a balancing weight, a sliding bearing, a polished rod and a positioning block, wherein the cam shaft is horizontally arranged and can be rotatably installed on the supporting platform, one end of the cam shaft is connected with the hand wheel, the other end of the cam shaft is connected with the cam, the cam is used for bearing the balancing weight so as to drive the balancing weight to move up and down, the sliding bearing is vertically installed on the supporting platform, the polished rod penetrates through the sliding bearing, the upper end of the polished rod is connected with the balancing weight, the lower end of the polished rod is connected with the positioning block, and the bottom of the positioning block is provided with;

the diamond adsorbs the rotating system to be located the below of locating piece, this diamond adsorbs the rotating system including the vacuum adsorption device who is used for adsorbing the lithodomous mesa and be used for driving vacuum adsorption device pivoted motor.

2. The diamond waistline viewer of claim 1, wherein the diamond positioning device further comprises an extension spring that is threaded through the polished rod, one end of the extension spring being fixedly connected to the weight block and the other end of the extension spring being fixedly connected to the support platform such that the weight block is always in contact with the cam.

3. The diamond waistline viewer of claim 1, wherein the imaging adjustment system includes a focusing mechanism for moving the imaging system in a side-to-side motion, an up-and-down motion for moving the imaging system in an up-and-down motion, and a one-dimensional position adjustment system for moving the imaging system in a front-and-back motion.

4. A diamond waistline viewer as claimed in claim 3, wherein the focusing means is a coarse and fine focus carriage.

5. The diamond waistline viewer of claim 1, wherein the microscope lens is connected to a zoom mechanism, the zoom mechanism is connected to the camera, and the zoom mechanism is mounted to the imaging adjustment system.

6. A diamond waistline viewer as claimed in claim 1, wherein the microscope head is further provided with an annular light source and/or a coaxial light source.

7. The diamond waistline observation instrument as claimed in claim 1, wherein the supporting platform is provided with a first limit pin and a second limit pin at positions corresponding to the cams, respectively, and the first limit pin is contacted with the cam to limit when the weight block reaches the highest position, and the second limit pin is contacted with the cam to limit when the weight block reaches the lowest position.

8. The diamond waistline observation instrument as claimed in claim 1, wherein the vacuum adsorption device comprises a rotary adsorption main shaft, a vacuum chamber, a motor and a two-dimensional moving platform, the rotary adsorption main shaft is vertically arranged, the lower end of the rotary adsorption main shaft passes through the vacuum chamber and then is connected with the motor through a coupler, and the two-dimensional displacement adjusting platform is connected with the motor for driving the motor to move up and down and back and forth.

9. The diamond waistline viewer of claim 1, wherein the vacuum chamber has a central air chamber, two main shaft matching chambers and two sealing ring mounting grooves, the central air chamber is located between the two main shaft matching chambers, the two main shaft matching chambers are located between the two sealing ring mounting grooves, a sealing ring is mounted in each sealing ring mounting groove, each sealing ring is fixedly sleeved on the rotary adsorption main shaft, the diameter of the central air chamber is larger than that of the main shaft matching chamber, the diameter of the main shaft matching chamber is larger than that of the rotary adsorption main shaft, the vacuum chamber is provided with an air suction hole communicated with the central air chamber, a threaded hole is formed in the inner wall of the air suction hole to connect with an air pump through an airtight threaded connector and a pipeline, and a vertical blind hole is formed along the axial direction of the rotary adsorption main shaft, the vertical blind hole extends downwards from the top end face of the rotary adsorption main shaft, and a radial hole for communicating the vertical blind hole with the central air chamber is formed in the radial direction of the rotary adsorption main shaft.

10. A method of observing the girdle of a diamond by a diamond girdle observer according to any one of claims 1 to 9, comprising the steps of:

1) placing the table top of the diamond on a vacuum adsorption device, and allowing the vacuum adsorption device to adsorb the diamond;

2) rotating the cam through the hand wheel to enable the polished rod to drive the positioning block to move downwards, moving the diamond to enable the diamond point to align to the positioning hole of the positioning block, continuing to move the positioning block downwards until the positioning block is in contact with the diamond to complete centering positioning of the diamond, and then rotating the hand wheel in the opposite direction to enable the positioning block to move upwards to be separated from the diamond;

3) adjusting the imaging adjustment system and the microscope lens to enable the camera to acquire the diamond waist line image with the required definition;

4) the method comprises the following steps of (1) calibrating the field width of an imaging system by using a line ruler on a camera;

5) obtaining the circumference and the radius of the waist line distribution circumference of the diamond through the weight of the diamond and a cutting method;

6) obtaining a central angle alpha corresponding to the diamond arc length acquired by a single view field according to the view field width in the step 4) and the radius of the circumference distributed on the waist line of the diamond in the step 5);

7) dividing 360 degrees by the central angle alpha, rounding the obtained quotient value to the direction of most number to obtain the nearest numerical value, and dividing 360 degrees by the rounded quotient value to obtain a numerical value serving as a new central angle beta;

8) and setting a single rotation angle value of a motor in the diamond adsorption rotation system according to the central angle beta, photographing and storing images once by a camera every time the motor rotates by the angle beta, and obtaining images of all positions of the waist line distribution circumference of the diamond through alternate rotation and photographing until the diamond rotates by 360 degrees.

Technical Field

The invention belongs to the technical field of measurement and detection of jewelry and jade, and particularly relates to a diamond waist line observation instrument and an observation method.

Background

The processing state of a diamond product is important information for measuring the diamond cutting technology and is also the unique geometrical characteristic of the diamond product. The waist line processing state and the geometric form of the diamond directly reflect the processing and grinding level of the diamond, which is an important embodiment of diamond processing technology capability and product quality, and meanwhile, the geometric dimension of the diamond waist line distributed on the circumference is an error accumulation result naturally formed by various procedures in the diamond processing process, the waist line geometric features of different diamond individuals have obvious difference, are inherent features of each diamond product, can be applied as identity marking information of a single diamond product, and provide important basis for the identity recognition, source tracing and supervision of the diamond product in the circulation process. Therefore, the diamond belt line state observation instrument is researched, accurate observation and recording of the diamond belt line state are carried out, and the diamond belt line state observation instrument has important significance for improving the diamond processing technology and identifying the identity.

At present, the jewelry appraisers generally rely on naked eyes for examination, and because the experience and the state of the jewelry appraisers are different, appraisal errors inevitably exist, so that the accuracy is not high enough.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides a diamond waistline observation instrument and an observation method, which are based on the circumferential distribution characteristics of waist forming of a large number of diamonds and are combined with an optical zoom imaging principle, a pneumatic rotary adsorption method and an image processing technology, so that the identification result is accurate.

To achieve the above object, according to one aspect of the present invention, there is provided a diamond waistline viewer, comprising a support platform, an imaging adjustment system, an imaging system, a diamond positioning device and a diamond adsorbing and rotating system, wherein:

the imaging adjusting system is arranged on the supporting platform, and the imaging system is arranged on the imaging adjusting system and is used for driving the imaging system to move left and right, front and back and up and down;

the imaging system comprises a microscope lens and a camera connected with the microscope lens, and is used for shooting a waist line picture of a diamond observed in the microscope, and the axis of the microscope lens extends along the left-right direction;

the diamond positioning device comprises a hand wheel, a cam shaft, a cam, a balancing weight, a sliding bearing, a polished rod and a positioning block, wherein the cam shaft is horizontally arranged and can be rotatably installed on the supporting platform, one end of the cam shaft is connected with the hand wheel, the other end of the cam shaft is connected with the cam, the cam is used for bearing the balancing weight so as to drive the balancing weight to move up and down, the sliding bearing is vertically installed on the supporting platform, the polished rod penetrates through the sliding bearing, the upper end of the polished rod is connected with the balancing weight, the lower end of the polished rod is connected with the positioning block, and the bottom of the positioning block is provided with;

the diamond adsorbs the rotating system to be located the below of locating piece, this diamond adsorbs the rotating system including the vacuum adsorption device who is used for adsorbing the lithodomous mesa and be used for driving vacuum adsorption device pivoted motor.

Preferably, the diamond positioning device further comprises an extension spring, the extension spring is arranged on the polished rod in a penetrating mode, one end of the extension spring is fixedly connected with the balancing weight, and the other end of the extension spring is fixedly connected with the supporting platform, so that the balancing weight is always in contact with the cam.

Preferably, the imaging adjustment system comprises a focusing device for driving the imaging system to move left and right, an upgrading adjustment system for driving the imaging system to move up and down, and a one-dimensional position adjustment system for driving the imaging system to move back and forth.

Preferably, the focusing device is a coarse and fine focusing bracket.

Preferably, the microscope is a continuous variable magnification embodiment microscope.

Preferably, the microscope head is also provided with an annular light source and/or a coaxial light source.

Preferably, the support platform is provided with a first limit pin and a second limit pin at positions corresponding to the cam respectively, and when the balancing weight reaches the highest position, the first limit pin contacts with the cam to limit, and when the balancing weight reaches the lowest position, the second limit pin contacts with the cam to limit.

Preferably, the vacuum adsorption device comprises a rotary adsorption main shaft, a vacuum cavity, a motor and a two-dimensional moving platform, the rotary adsorption main shaft is vertically arranged, the lower end of the rotary adsorption main shaft penetrates through the vacuum cavity and then is connected with the motor through a coupler, and the two-dimensional displacement adjusting table is connected with the motor and used for driving the motor to move up and down and back and forth.

Preferably, the vacuum cavity has a central air chamber, two main shaft matching chambers and two sealing ring mounting grooves, the central air chamber is located between the two main shaft matching chambers, the two main shaft matching chambers are located between the two sealing ring mounting grooves, a sealing ring is mounted in each sealing ring mounting groove, each sealing ring is fixedly sleeved on the rotary adsorption main shaft, the diameter of the central air chamber is larger than that of the main shaft matching chamber, the diameter of the main shaft matching chamber is larger than that of the rotary adsorption main shaft, an air suction hole communicated with the central air chamber is arranged on the vacuum cavity, a threaded hole is arranged on the inner wall of the air suction hole to be connected with an air pump through an airtight threaded connector and a pipeline, a vertical blind hole is arranged along the axial direction of the rotary adsorption main shaft, and the vertical blind hole extends downwards from the top end face of the rotary adsorption main, and radial holes communicated with the vertical blind holes and the central air chamber are arranged along the radial direction of the rotary adsorption main shaft.

According to another aspect of the present invention, there is provided a method for observing a diamond waistline by a diamond waistline observer, comprising the steps of:

1) placing the table top of the diamond on a vacuum adsorption device, and allowing the vacuum adsorption device to adsorb the diamond;

2) rotating the cam through the hand wheel to enable the polished rod to drive the positioning block to move downwards, moving the diamond to enable the diamond point to align to the positioning hole of the positioning block, continuing to move the positioning block downwards until the positioning block is in contact with the diamond to complete centering positioning of the diamond, and then rotating the hand wheel in the opposite direction to enable the positioning block to move upwards to be separated from the diamond;

3) adjusting the imaging adjustment system and the microscope lens to enable the camera to acquire the diamond waist line image with the required definition;

4) the method comprises the following steps of (1) calibrating the field width of an imaging system by using a line ruler on a camera;

5) obtaining the circumference and the radius of the waist line distribution circumference of the diamond through the weight of the diamond and a cutting method;

6) obtaining a central angle alpha corresponding to the diamond arc length acquired by a single view field according to the view field width in the step 4) and the radius of the circumference distributed on the waist line of the diamond in the step 5);

7) dividing 360 degrees by the central angle alpha, rounding the obtained quotient value to the direction of most number to obtain the nearest numerical value, and dividing 360 degrees by the rounded quotient value to obtain a numerical value serving as a new central angle beta;

8) and setting a single rotation angle value of a motor in the diamond adsorption rotation system according to the central angle beta, photographing and storing images once by a camera every time the motor rotates by the angle beta, and obtaining images of all positions of the waist line distribution circumference of the diamond through alternate rotation and photographing until the diamond rotates by 360 degrees.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

1) the imaging adjusting system can conveniently adjust the position of a microscope of the imaging system, the imaging system can clearly shoot the waist line of the diamond, the diamond positioning device can align and center the diamond, and the diamond adsorption rotating system can adsorb the diamond and rotate the diamond, so that the imaging system can shoot the waist line of the diamond in 360 degrees in an all-round way, the identification and the appraisal can be conveniently carried out through the waist line of the diamond, and the appraisal result is accurate.

2) The diamond positioning device drives the polished rod and the positioning block to move up and down through the rotation of the cam, has a compact structure and high reliability, and ensures that the diamond drill point can stretch into the positioning hole of the positioning block to perform self-adaptive alignment and centering, thereby being beneficial to the accurate photographing and observation of the imaging system on the diamond.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a left side view of the present invention;

FIG. 3 is a schematic view of the assembly of the rotary adsorption spindle and the vacuum chamber of the present invention;

FIG. 4a is a schematic view of various parts of a diamond;

fig. 4b is an image taken at a along the belt line in fig. 4 a.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to the figures, a diamond stringcourse viewer comprises a support platform, an imaging adjustment system, an imaging system, a diamond positioning device 31 and a diamond adsorption rotation system, wherein:

the imaging adjusting system is arranged on the supporting platform, and the imaging system is arranged on the imaging adjusting system and is used for driving the imaging system to move left and right, front and back and up and down;

the imaging system comprises a microscope lens 11 and a camera 13 connected with the microscope lens, and is used for shooting a waist line picture of a diamond observed in the microscope lens 11, wherein the axis of the microscope lens 11 extends along the left-right direction;

the diamond positioning device 31 comprises a hand wheel 312, a cam shaft 314, a cam 310, a balancing weight 301, a sliding bearing 304, a polished rod 303 and a positioning block 305, wherein the cam shaft 314 is horizontally arranged and rotatably mounted on a vertical flat plate 311 of the supporting platform through a radial bearing 313, one end of the cam shaft 314 is connected with the hand wheel 312, the other end of the cam shaft 314 is connected with the cam 310, the cam 310 receives the balancing weight 301 to drive the balancing weight 301 to move up and down, the sliding bearing 304 is vertically mounted in a horizontal supporting flat plate 51 of the supporting platform, the polished rod 303 penetrates through the sliding bearing 304, the upper end of the polished rod 303 is connected with the balancing weight 301, the lower end of the polished rod 303 is connected with the positioning block 305, and the bottom of the positioning block 305 is provided with a; the bottom of the positioning block 305 is preferably a tapered structure with a large top and a small bottom, and the positioning hole is arranged on the tapered structure, so that the threaded connection strength of the upper part is ensured, the small-sized diamond can be conveniently and quickly positioned to the blind hole, and meanwhile, a larger reflection inclination angle is formed between the tapered surface and the axis of the microscope lens 11, so that interference caused by the background light reflected into the lens hole of the microscope lens 11 after the coaxial light source 12 irradiates is prevented

The diamond adsorption rotation system is located below the positioning block 305, and the diamond adsorption rotation system comprises a vacuum adsorption device for adsorbing a diamond table and a motor 45 for driving the vacuum adsorption device to rotate.

Further, the diamond positioning device 31 further comprises an extension spring 302, the extension spring 302 is mounted on the polish rod 303 in a penetrating manner, one end of the extension spring 302 is fixedly connected with the counterweight 301, and the other end of the extension spring 302 is fixedly connected with the supporting platform, so that the counterweight 301 is always in contact with the cam 310.

Further, the imaging adjustment system comprises a focusing device 21 for driving the imaging system to move left and right, an upgrading adjustment system for driving the imaging system to move up and down, and a one-dimensional position adjustment system 23 for driving the imaging system to move back and forth.

Further, the focusing device 21 is a coarse and fine focusing bracket, and the coarse and fine focusing bracket can perform coarse and fine adjustment on the focal length of the microscope.

Furthermore, the microscope lens is connected with a zooming mechanism, the zooming mechanism is connected with the camera, and the zooming mechanism is installed on the imaging adjusting system. The microscope lens 11 is preferably an apo (apochromatic) flat-field lens or a dark-field microscope lens, the zoom mechanism 12 may be of various types, and the microscope lens 11 and the zoom mechanism 12 may be combined in various forms.

Further, an annular light source 15 and/or a coaxial light source 14 are mounted on the microscope. Referring to fig. 1, the light emitting point of the coaxial light source 12 is inserted into the lens barrel of the microscope lens 11, and the light is collimated by the spectroscope and then coaxial with the microscope lens, so that the accuracy and reproducibility of vision are improved, and the terminal and the heat sink are exposed and face the supporting platform.

Further, the support platform is provided with a first limit pin and a second limit pin at positions corresponding to the cam 310, respectively, and when the counterweight 301 reaches the highest position, the first limit pin contacts with the cam 310 to limit, and when the counterweight 301 reaches the lowest position, the second limit pin contacts with the cam 310 to limit. At two limiting positions of the first limiting pin and the second limiting pin, the cam and all moving parts contacted with the cam can be kept stable and static under the action of gravity.

Further, the vacuum adsorption device comprises a rotary adsorption main shaft 41, a vacuum cavity 42, a motor 45 and a two-dimensional moving platform, wherein the rotary adsorption main shaft 41 is vertically arranged, the lower end of the rotary adsorption main shaft 41 penetrates through the vacuum cavity 42 and then is connected with the motor 45 through a coupler 43, and the two-dimensional displacement adjusting table 47 is connected with the motor 45 so as to drive the motor 45 to move up and down and back and forth. Preferably, a first L-shaped rib plate 46 and a second L-shaped rib plate 48 are respectively arranged on two sides of the bottom end face of the vacuum cavity 42, and the bottoms of the first L-shaped rib plate 46 and the second L-shaped rib plate 48 are connected with a two-dimensional displacement adjusting table 47 to play a role in strengthening and supporting. The two-dimensional displacement adjusting table 47 is used for enabling the central line of the rotary adsorption main shaft and the central line of the positioning block to be collinear, and is used for eliminating the assembly rotating center and center alignment error adjusting of the instrument, the one-dimensional displacement adjusting device 23 is used for adjusting the optical axis of the microscope during assembly of the instrument, so that the optical axis and the central line of the rotary adsorption main shaft are coplanar with the central line of the positioning block, and the distances from the plane where the optical axis is located to the positioning block and the rotary adsorption main shaft are equal, so that errors of manual assembly are eliminated. The two-dimensional displacement adjusting table 47 and the one-dimensional adjusting device 23 are used for adjusting during assembling of the observation instrument, locking is performed after adjustment, the observation instrument reaches a qualified state, and when the observation instrument is measured and used after leaving a factory, the two-dimensional displacement adjusting table 47 and the one-dimensional adjusting device 23 are not allowed to be adjusted.

Further, the vacuum cavity 42 has a central air chamber 422, two main shaft matching chambers and two sealing ring mounting grooves, the central air chamber 422 is located between the two main shaft matching chambers, the two main shaft matching chambers are located between the two sealing ring mounting grooves, an upper main shaft matching chamber 421 and a lower main shaft matching chamber 424 are respectively provided, each sealing ring mounting groove is internally provided with a sealing ring, the two sealing rings are respectively an upper sealing ring 425 and a lower sealing ring 426, each sealing ring is fixedly sleeved on the rotary adsorption main shaft 41, the diameter of the central air chamber 422 is larger than that of the main shaft matching chamber, the diameter of the main shaft matching chamber is larger than that of the rotary adsorption main shaft 41, the vacuum cavity 42 is provided with an air suction hole communicated with the central air chamber 422, the inner wall of the air suction hole is provided with a threaded hole 423 for connecting with an air pump through an airtight threaded joint and a pipeline, a vertical blind hole is formed in the axial direction of the rotary adsorption main shaft 41, the vertical blind hole extends downwards from the top end face of the rotary adsorption main shaft 41, and a radial hole communicated with the vertical blind hole and the central air chamber 422 is formed in the radial direction of the rotary adsorption main shaft 41. The depth of the vertical blind hole is larger than the distance from the upper end face of the rotary adsorption main shaft 41 to the middle part of the central air chamber 422, and the radial hole can enable external air on the upper end face of the rotary adsorption main shaft 41 to sequentially pass through the vertical blind hole of the rotary adsorption main shaft 41, the radial hole, the central air chamber 422 and a threaded pipeline to be communicated with an air pump. When the diamond table surface is placed downwards on the end surface of the rotary adsorption main shaft 41 and covers the opening of the vertical blind hole, the air pump is started to suck air, negative pressure adsorption force is formed by the opening of the upper end surface inside the vertical blind hole of the rotary adsorption main shaft 41, and the diamond is ensured to be firmly adsorbed on the upper end surface of the rotary adsorption main shaft 41 in the rotating process of the rotary adsorption main shaft 41 and synchronously rotate along with the rotary adsorption main shaft 41 without slipping.

According to another aspect of the present invention, there is provided a method of observing a diamond waistline using a diamond waistline observer, comprising the steps of:

1) placing the table top of the diamond on a vacuum adsorption device, and allowing the vacuum adsorption device to adsorb the diamond;

2) the hand wheel 312 of the cam rotating mechanism 31 is rotated, so that the polished rod 303 drives the positioning block 305 to move downwards, the diamond tip is placed in the positioning hole of the positioning block 305 by moving the diamond, the positioning block 305 is continuously moved downwards until the positioning block 305 is contacted with the diamond, then the hand wheel 312 is reversed, the positioning block 305 is moved upwards to be separated from the diamond, and centering positioning of the diamond is completed.

3) Adjusting an imaging adjusting system (a focusing device 21 and a lifting adjusting device 22 of the imaging adjusting system) and adjusting a zooming mechanism 12 in the imaging system, so that the size of the diamond waist line image acquired by the camera 13 is proper, the image is clear, and the required definition is met;

4) the visual field width value of the imaging system is calibrated by adopting the line ruler, and the specific measurement standard calibration method can be referred to in the reference of the visual detection calibration method based on the line ruler.

5) Calculating the circumference and radius of the circumference of the waist line distribution of the diamond through the weight and cutting method of the diamond, and referring to the reference GBT-16554-2017 diamond classification;

6) obtaining a central angle alpha corresponding to the diamond arc length acquired by a single view field according to the view field width in the step 4) and the radius of the circumference distributed on the waist line of the diamond in the step 5);

7) dividing 360 degrees by the central angle alpha, rounding the obtained quotient value to the direction of most number to obtain the nearest numerical value, and dividing 360 degrees by the rounded quotient value to obtain a numerical value serving as a new central angle beta;

8) and setting a single rotation angle value of the motor 45 in the diamond adsorption rotation system according to the value of the new central angle beta, driving the diamond to rotate by the motor 45 again, photographing and storing images once by the camera 13 every time the motor 45 rotates by the angle beta, and alternately rotating and photographing until the diamond rotates to 360 degrees to obtain images of all positions of the waist line distribution circumference of the diamond.

Further, this step 4) can be omitted during reuse of the scope. When the observation instrument is used for the first time or the adjustment operation of the magnification-varying mechanism 12 described in step 3) is performed, the operation of step 4) must be performed to obtain a new value of the field width.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.