Gem identification method and apparatus

Patent metadata

Field	Value
Publication number	US-10036707-B2
Application number	US-201414576752-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 27, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

Embodiments of the present invention provide jewel and jade identification method and apparatus. The method comprises the steps: (a) placing a sample to be detected over a light transmission hole formed on a carrying surface of an object table and emitting, by an optical probe disposed below the carrying surface, an exciting light onto the sample through the light transmission hole and then collecting a Raman scattered light from the sample by the optical probe. (b) acquiring a Raman spectrum curve of the sample from the collected Raman scattered light from the sample; and (c) comparing the Raman spectrum curve with a reference Raman spectrum library for jewels and jades to identify the sample. The method and apparatus may achieve effective, convenient and accurate inspections of the jewels and jades.

First claim

What is claimed is:

1. A jewel and jade identification method, comprising steps of:
(a) placing a sample to be detected over one or more light transmission holes on a carrying surface of an object table and emitting, by an optical probe disposed below the carrying surface, an exciting light onto the sample through the light transmission hole and then collecting a Raman scattered light from the sample by the optical probe, wherein diameters of the light transmission holes are variable;
(b) acquiring a Raman spectrum curve of the sample from the collected Raman scattered light from the sample; and
(c) comparing the Raman spectrum curve with a reference Raman spectrum library for jewels and jades to identify the sample,
wherein focal position of the exciting light is located adjacent to the light transmission hole.

2. The jewel and jade identification method according to claim 1 , further comprising, before the step (a), following step of:
(o) measuring Raman spectra of reference samples of jewels and jades having known compositions and/or Raman spectra of fakes, to obtain reference Raman spectra so as to establish the reference Raman spectrum library.

3. The jewel and jade identification method according to claim 1 or 2 , further comprising:
(d) placing another sample to be detected over another light transmission hole on the carrying surface of the object table and moving the object table with respect to the optical probe in a horizontal direction such that the optical probe emits the exciting light onto the another sample through the another light transmission hole and collects a Raman scattered light from the another sample;
(e) acquiring a Raman spectrum curve of the another sample from the collected Raman scattered light from the another sample; and
(f) comparing the Raman spectrum curve of the another sample with the reference Raman spectrum library for jewels and jades to identify the another sample.

4. The jewel and jade identification method according to claim 1 or 2 , wherein the step (c) comprises:
(c1) calculating a similarity degree between the Raman spectrum curve and reference Raman spectrum curves in the reference Raman spectrum library.

5. The jewel and jade identification method according to claim 4 , wherein the similarity degree is defined as

Corr
=

(

1
-

1
-

A
⁡

(
x
)

·

B
⁡

(
x
)

A
⁡

(
x
)

·

A
⁡

(
x
)

⁢

B
⁡

(
x
)

·

B
⁡

(
x
)

)

×
100
⁢
%

,

where A(x) is a Raman spectrum curve function of the sample to be detected and B(x) is a reference Raman spectrum curve function.

6. The jewel and jade identification method according to claim 4 , wherein the similarity degree is defined as

Corr
=

(

(

A
⁡

(
x
)

-

∑

i
=
1

n

⁢

A
i

n

)

·

(

B
⁡

(
x
)

-

Assignees

• Nuctech Co Ltd
• Univ Tsinghua

Inventors

• Zhao Ziran
• Zhang Li
• Geng Yingying
• Wang Hongqiu
• Yi Yumin

Classifications

• G01J3/4412

  Scattering spectrometry (particle sizing by light scattering G01N15/0205; optical velocimetry of particles G01P5/20, G01P5/26) · CPC title

• G01J3/44

  Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} · CPC title

• G01N2201/06113

  Coherent sources; lasers · CPC title

• G01N21/87

  Investigating jewels (G01N21/88 takes precedence) · CPC title

• G01J3/28

  Investigating the spectrum (using colour filters G01J3/51) · CPC title