CN109141254A - A kind of integrated diffraction grating formula high stability laser displacement sensor - Google Patents
A kind of integrated diffraction grating formula high stability laser displacement sensor Download PDFInfo
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- CN109141254A CN109141254A CN201811199026.8A CN201811199026A CN109141254A CN 109141254 A CN109141254 A CN 109141254A CN 201811199026 A CN201811199026 A CN 201811199026A CN 109141254 A CN109141254 A CN 109141254A
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- Prior art keywords
- diffraction grating
- displacement
- laser
- diffraction
- displacement sensor
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
Abstract
The invention discloses a kind of integrated diffraction grating formula high stability laser displacement sensors, including sensor body, the collimating module containing laser diode, diffraction grating, diaphragm, optical filter, imaging len and CMOS linear imaging sensor in the sensor body.The laser collimation modules of the laser displacement sensor issue collimated light beam, light beam passes through the diffusing reflection of measured object surface, after diaphragm and imaging len, hot spot is beamed into multiple diffraction patterns by special transmissive diffraction grating, it is utilized respectively the displacement of each diffraction pattern reverse measured object, by carrying out average by the multiple displacement datas resolved or median being taken to handle, the actual displacement of measured object can be obtained.The invention in the case where measurement primary displacement, resolves measured object using the information of multiple diffraction patterns and is displaced, the influence of the environmental factors such as noise is reduced, to effectively improve the stability of measurement data compared with conventional laser triangulation sensor.
Description
Technical field
The present invention relates to a kind of displacement measuring instrument, in particular to a kind of integrated diffraction grating formula high stability laser displacement
Sensor.
Background technique
Laser triangulation method is one kind of photoelectric detecting method, and this method structure is simple, measurement accuracy is high, real-time place
Reason ability is strong, flexible and convenient, the advantages that not influenced by testee surface, in distance, displacement, surface shape and three-dimensional appearance
Using extensive in detection.
Laser triangular distance measuring apparatus is generally by laser diode, laser beam datum lens, imaging len and image detector group
At its main feature is that having certain angle between laser beam optical path, lens imaging optical path and image detector, so that imaging
It clearly converges always on the image sensor.It is correspondingly, formed on the image sensor when the position of object changes
Also simultaneously certain change occurs for the position of picture, and the relationship moved by image displacement and level calculates the displacement of real-world object.
In recent years, with the continuous development of science and technology, there is higher requirement in precision and range of the industrial circle to measurement,
Especially in micro-nano detection field, device dimension is minimum, stringenter to the required precision of size, to laser triangulation system
The signal stabilization requirement of system is higher and higher, and traditional laser triangulation system is only capable of being mentioned in terms of hardware and software
It is high.
Summary of the invention
In order to overcome the disadvantages of the above prior art, it is high steady that the purpose of the present invention is to provide a kind of integrated diffraction grating formulas
Qualitative laser displacement sensor, the hot spot picture point diffraction that will be detected using diffraction grating, while utilizing the displacement of multiple picture points
Ohject displacement is found out, the influence of the environmental factors such as noise is reduced, to effectively improve the stability of measurement data.
To achieve the goals above, the technical solution adopted by the present invention is that:
A kind of integrated diffraction grating formula laser displacement sensor, including sensor body 10, in the sensor body 10
It is passed equipped with laser diode 1 and collimation lens 2, diaphragm 3, optical filter 6, imaging len 7, diffraction grating 8 and CMOS linear image
Sensor 9, which is characterized in that the laser diode 1 emits collimated laser beam 4 by collimation lens 2, which passes through diaphragm
After 3, it is projeced into 5 surface of sample outside sensor body, what 5 surface of sample generated diffuses by optical filter 6 and imaging
Lens 7, then multiple diffraction patterns are diffracted into through diffraction grating 8, it is incident upon on CMOS linear imaging sensor 9.
The diffraction grating 8 is transmission-type grating, possesses 4 μm of period, and with a thickness of 0.5mm, grating groove profile is rectangle
Or triangle or sinusoidal, groove depth is within the scope of 400-430nm, duty ratio 1:1.
Imaging facula is diffracted into multiple (being more than or equal to 3) by the diffraction grating 8.
In the diffraction pattern that 8 beam splitting of diffraction grating is formed, 11,0 grades of hot spots 12 of -1 grade of hot spot and+1 grade of hot spot 13
Diffraction efficiency is identical.
8 installation site of diffraction grating is away from lens, and installation direction is parallel with receiving lens, such as diffraction grating
8 and receiving lens distance can be 25mm.
Under the conditions of the wavelength of laser light source used is the feux rouges of 650nm, the groove depth control of the 8 grating groove profile of diffraction grating
System is in the range of 400-430nm, so that the diffraction efficiency highest of ± 1 grade of hot spot and 0 grade of hot spot that diffraction goes out, light intensity accounting
Within the scope of 28%-29%.
The present invention may also include aperture diaphragm, and the aperture diaphragm and optical filter 6 are integrally formed, or are separately set in filter
Between mating plate 6 and imaging len 7, cooperates optical filter 6, for filtering out stray light, and reduce coma.
After the CMOS linear imaging sensor 9 receives multiple diffraction patterns, using laser triangulation, it is utilized respectively
Each diffraction grating information resolves measured object displacement, carries out average by the displacement data solved using each hot spot or takes middle position
Value, finally obtains the actual displacement of measured object.In the case where measurement primary displacement, resolved using the information of multiple diffraction patterns
Measured object displacement, reduces the influence of the environmental factors such as noise, to effectively improve the stability of measurement data.
Compared with prior art, the present invention by introducing diffraction grating in the optical path, so that imaging hot spot passes through diffraction
Hot spot is diffracted into multiple, and CMOS linear imaging sensor detects multiple spot displacements simultaneously, asks its average or median as institute
The final result for asking displacement reduces the shake of displacement data, reduces the factors such as ambient noise, improves the stability of data.
Detailed description of the invention
Fig. 1 is the index path of conventional laser range of triangle instrument.
Fig. 2 is schematic structural view of the invention.
Fig. 3 is diffraction grating structure schematic diagram of the present invention.
It is indicated in figure: 1- laser diode；2- laser collimator lens；3- collimation diaphragm；4- laser beam；5- measured object table
Face；6- optical filter and diaphragm；7- imaging len；8- transmissive diffraction grating；9-CMOS linear imaging sensor；10- instrument sheet
Body；11,12, -1 grade, 0 grade and+1 grade of hot spot of 13- diffraction out.
Specific embodiment
In order to deepen the understanding of the present invention, below in conjunction with embodiment and attached drawing, the invention will be further described, should
The examples are only for explaining the invention, is not intended to limit the scope of the present invention..
Conventional laser range of triangle instrument in sensor body 10 as shown in Figure 1, be arranged laser diode 1, collimating module
2, diaphragm 3, optical filter and diaphragm 6, imaging len 7 and CMOS linear imaging sensor 9.Laser diode 1 passes through collimating module 2
Emit collimated laser beam, which reduces the laser beam 4 after hot spot by diaphragm 3, and direct perpendicular projection is in sensor sheet
5 surface of sample outside body 10, sample surfaces diffuse by optical filter 6 and imaging len 7, at hot spot picture be incident upon
On CMOS linear imaging sensor 9.In this case, using a branch of optical path carry out displacement detecting, can not to it is detected be displaced into
Row feedback modifiers and the electronic interferences for reducing the factors such as ambient noise.
And structure of the invention after imaging len 7 as shown in Fig. 2, be provided with the diffraction grating 8 of transmission-type, it is saturating to being imaged
The light beam that mirror 7 converges is split, and finally the picture for being formed by multiple hot spots is incident upon on CMOS linear imaging sensor 9,
Wherein lens axis and laser beam axis angle α are 20 °, and object distance S is 136mm, image distance s value 30mm on lens axis, therefore lens
Optical axis and the angle of photodetector image planes are 58.78 °.
In the present embodiment, hot spot imaging is diffracted into three (11,0 grades of hot spots 12 of -1 grade of hot spot and+1 grades by diffraction grating 8
Hot spot 13), it as needed, can also be more.The structure of diffraction grating 8 possesses specific week as shown in figure 3, groove profile is rectangle
Phase t (the present embodiment takes 4 μm) and groove profile, substrate of glass are in the light source of the instrument with a thickness of 0.5mm, grating groove profile
It is rectangular, duty ratio 1:1 when the laser diode of 650nm wavelength, i.e., it is 2 that the wide b of groove profile ridge is equal with groove width a width
μm, installation site is maintained within the scope of 400-430nm apart from receiving lens 25mm, groove depth h, can make ± 1 grade of spot intensity
Identical as 0 grade of spot intensity, diffraction efficiency highest, spot intensity accounting are more in post-processing within 28%-29% at this time
It can be more simply easy when a spot signal.
After CMOS linear imaging sensor 9 detects multiple spot signals, when testee is displaced,
The picture of multiple hot spots on sensor is also subjected to displacement simultaneously, due to the ohject displacement and picture of the laser triangulation in small range
Displacement can be calculated with approximately linear, it is possible to be passed through the displacements of multiple hot spots while be obtained the displacement of multiple objects, will obtain
The multiple displacement results obtained seek average or median as final result, in the case where measurement primary displacement, utilization
The information of multiple diffraction patterns resolves measured object displacement, the influence of the environmental factors such as noise is reduced, to effectively improve measurement
The stability of data.
Using similar triangles and Ge Bian proportionate relationship, it is as follows to calculate displacement derivation formula:
There is grating formula simultaneously:
p(sinθi+sinθm)=m λ
Wherein:
In above formula:
d+m、d-m, d be respectively diffraction go out three hot spots on CMOS linear imaging sensor 9 institute at+m grade hot spots (
+ 1 is taken in example) 11 and 0 grades of 13 ,-m grades of hot spots (- 1 is taken in this example) 12 relative fiducial positions of hot spot when displacement；
S is image planes (i.e. Linear CMOS sensor cover) at a distance from imaging len 7 is on optical axis；
S be on base position measured object at a distance from imaging len 7 is on optical axis；
β is the angle of CMOS linear imaging sensor 9 and 7 optical axis of imaging len；
Angle of the α between laser beam and imaging len 7；
M is the diffraction time (± 1 is chosen in this example) of grating fringe；
s1It is grating at a distance from receiving lens；
P is the pitch size of grating；
λ is the wavelength of laser light source；
θiIt is laser to the incidence angle of grating；
θmFor the angle of diffraction；
To sum up, it is even more using transmissive diffraction grating to be beamed into three tunnels by the present invention for hot spot, can by above-mentioned formula
To obtain the displacement of the picture of the hot spot on three photodetectors, obtain three testees displacement be averaged after export,
As final result.Compared with general laser triangular distance measuring apparatus, for the present invention in the case where measurement primary displacement, utilization is multiple
The information of diffraction pattern resolves measured object displacement, the influence of the environmental factors such as noise is reduced, to effectively improve measurement data
Stability.
Claims (9)
1. a kind of integrated diffraction grating formula laser displacement sensor, including sensor body (10), the sensor body (10)
It is interior be equipped with laser diode (1) and collimation lens (2), diaphragm (3), optical filter (6), imaging len (7), diffraction grating (8) and
CMOS linear imaging sensor (9), which is characterized in that the laser diode (1) emits collimation laser by collimation lens (2)
Beam (4), the laser beam pass through after diaphragm (3), are projeced into sample (5) surface outside sensor body, and sample (5) surface generates
Diffuse by optical filter (6) and imaging len (7), then be diffracted into multiple diffraction patterns through diffraction grating (8), be incident upon
On CMOS linear imaging sensor (9).
2. integrated diffraction grating formula laser displacement sensor according to claim 1, which is characterized in that the diffraction grating
(8) it is transmission-type grating, possesses 4 μm of period, with a thickness of 0.5mm, grating groove profile is rectangle or triangle or sinusoidal, slot
Deeply within the scope of 400-430nm, duty ratio 1:1.
3. integrated diffraction grating formula laser displacement sensor according to claim 1, which is characterized in that the diffraction grating
(8) imaging facula is diffracted into multiple.
4. integrated diffraction grating formula laser displacement sensor according to claim 3, which is characterized in that the diffraction grating
(8) in the diffraction pattern that beam splitting is formed, -1 grade of hot spot (11), 0 grade of hot spot (12) are identical with the diffraction efficiency of+1 grade of hot spot (13).
5. integrated diffraction grating formula laser displacement sensor according to claim 3, which is characterized in that the diffraction grating
(8) installation site is away from lens.
6. integrated diffraction grating formula laser displacement sensor according to claim 3, which is characterized in that the diffraction grating
It (8) is 25mm with receiving lens distance.
7. being existed according to integrated diffraction grating formula laser displacement sensor, feature described in claim 2 to 6 any claim
In, under the conditions of the wavelength of laser light source used is the feux rouges of 650nm, the groove depth control of diffraction grating (8) the grating groove profile
In the range of 400-430nm, so that the light intensity accounting of ± 1 grade of hot spot and 0 grade of hot spot that diffraction goes out is in 28%-29% model
In enclosing.
8. integrated diffraction grating formula laser displacement sensor according to claim 1, which is characterized in that further include aperture light
Door screen, the aperture diaphragm and optical filter (6) are integrally formed, or are separately set between optical filter (6) and imaging len (7),
Cooperate optical filter (6), for filtering out stray light, and reduces coma.
9. integrated diffraction grating formula laser displacement sensor according to claim 1, which is characterized in that the CMOS linear graph
After receiving multiple diffraction patterns as sensor (9), using laser triangulation, it is utilized respectively each diffraction grating information and resolves
The displacement data solved using each hot spot is carried out average or takes median, finally obtains the reality of measured object by measured object displacement
Border displacement.
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| CN201811199026.8A CN109141254A (en) | 2018-10-15 | 2018-10-15 | A kind of integrated diffraction grating formula high stability laser displacement sensor |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111174707A (en) * | 2020-01-08 | 2020-05-19 | 淮阴师范学院 | Photoelectric micro-displacement measuring device |
| CN111812933A (en) * | 2020-08-10 | 2020-10-23 | 陈方 | Grating space imaging projection optical system |
| CN116068567A (en) * | 2023-04-07 | 2023-05-05 | 天津宜科自动化股份有限公司 | Ranging system based on laser triangular ranging sensor |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101226892A (en) * | 2007-01-15 | 2008-07-23 | 株式会社迪思科 | Measuring apparatus for work held by chuck table, and laser beam machining apparatus |
| CN101701847A (en) * | 2009-11-27 | 2010-05-05 | 中国科学院光电技术研究所 | Imaging system for wide dynamic range based on optical grating and CCD imaging detector |
| CN102419213A (en) * | 2011-12-20 | 2012-04-18 | 四川大学 | Hartmann wavefront sensor based on diffraction grating arrays |
| CN103528528A (en) * | 2013-10-18 | 2014-01-22 | 苏州精创光学仪器有限公司 | Compact type precise laser triangular range finder |
| CN107076548A (en) * | 2014-11-13 | 2017-08-18 | 株式会社高永科技 | Utilize the 3 d shape measuring apparatus of diffraction grating |
| CN108633328A (en) * | 2015-05-05 | 2018-10-09 | 微软技术许可有限责任公司 | Via the long-range depth sense for determining repeated depth by diffusion |
-
2018
- 2018-10-15 CN CN201811199026.8A patent/CN109141254A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101226892A (en) * | 2007-01-15 | 2008-07-23 | 株式会社迪思科 | Measuring apparatus for work held by chuck table, and laser beam machining apparatus |
| CN101701847A (en) * | 2009-11-27 | 2010-05-05 | 中国科学院光电技术研究所 | Imaging system for wide dynamic range based on optical grating and CCD imaging detector |
| CN102419213A (en) * | 2011-12-20 | 2012-04-18 | 四川大学 | Hartmann wavefront sensor based on diffraction grating arrays |
| CN103528528A (en) * | 2013-10-18 | 2014-01-22 | 苏州精创光学仪器有限公司 | Compact type precise laser triangular range finder |
| CN107076548A (en) * | 2014-11-13 | 2017-08-18 | 株式会社高永科技 | Utilize the 3 d shape measuring apparatus of diffraction grating |
| CN108633328A (en) * | 2015-05-05 | 2018-10-09 | 微软技术许可有限责任公司 | Via the long-range depth sense for determining repeated depth by diffusion |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111174707A (en) * | 2020-01-08 | 2020-05-19 | 淮阴师范学院 | Photoelectric micro-displacement measuring device |
| CN111174707B (en) * | 2020-01-08 | 2021-06-22 | 淮阴师范学院 | Photoelectric micro-displacement measuring device |
| CN111812933A (en) * | 2020-08-10 | 2020-10-23 | 陈方 | Grating space imaging projection optical system |
| CN116068567A (en) * | 2023-04-07 | 2023-05-05 | 天津宜科自动化股份有限公司 | Ranging system based on laser triangular ranging sensor |
| CN116068567B (en) * | 2023-04-07 | 2023-06-13 | 天津宜科自动化股份有限公司 | Ranging system based on laser triangular ranging sensor |
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Application publication date: 20190104 |