CN216132667U - Speckle size and collimating lens focal length measuring device - Google Patents
Speckle size and collimating lens focal length measuring device Download PDFInfo
- Publication number
- CN216132667U CN216132667U CN202121590174.XU CN202121590174U CN216132667U CN 216132667 U CN216132667 U CN 216132667U CN 202121590174 U CN202121590174 U CN 202121590174U CN 216132667 U CN216132667 U CN 216132667U
- Authority
- CN
- China
- Prior art keywords
- diffuse transmission
- motion platform
- axis
- laser module
- camera unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
The utility model relates to the technical field of machinery, optics and electronics, and discloses a device for measuring the size of speckles and the focal length of a collimating lens, which comprises a laser module, a diffuse transmission screen, a motion mechanism, a camera unit and a processor, wherein the camera unit is fixed on one side of the diffuse transmission screen, which is far away from the laser module, the lens optical axis of the camera unit is perpendicular to the transmission surface of the diffuse transmission screen, the laser module comprises a light source and a collimating lens, speckles projected by the light source pass through the collimating lens and form diffuse transmission on the diffuse transmission screen, the camera unit can collect the speckles on the diffuse transmission screen to obtain speckle patterns, the processor is used for calculating the size of the speckles and the focal length of the collimating lens according to the speckle patterns, the laser module is arranged on the motion mechanism, and the motion mechanism can adjust the position of the laser module so that the optical axis of the light source and the lens optical axis of the camera unit are on the same axis. The utility model can ensure the accuracy of measurement, save cost and reduce the workload of operators.
Description
Technical Field
The utility model relates to the technical field of machinery, optics and electronics, in particular to a device for measuring the size of speckles and the focal length of a collimating lens.
Background
In 3D (3-dimensional) sensing technologies such as i-TOF (indirect time of flight), D-TOF (direct time of flight), structured light, etc., the spot size is the spot diameter of a light beam on a perpendicular plane to an Optical axis direction, and is an important parameter for evaluating speckle performance (energy density, etc.), and the focal length of a collimating mirror of a laser module has an important significance for evaluating the collimating mirror, evaluating the spot size, analyzing the speckle, etc., and also affects the design of DOE (differential Optical Elements, Diffractive Optical Elements), so that the focal length of the collimating mirror of the module needs to be accurately measured. In the related art, as shown in fig. 1, a camera is used to collect laser speckles projected onto a diffuse reflection screen, the size of the speckles is calculated, and a collimator focal length f is calculated as H × S/(L + S) based on the size S of a laser light emitting area, the size L projected onto a reflection plane, and the distance H from a laser module to the reflection plane. However, this measurement method has the following drawbacks: 1. when the optical axes of the laser module and the camera are not perpendicular to the plane, the focal length test of the collimating lens is inaccurate, calculation deviation exists, and even a trailing phenomenon can occur; 2. after the distance between the laser module and the reflecting plane is changed, the camera lens needs to be frequently replaced in order to better collect speckle patterns; 3. when the diffuse reflection screen is used for testing, the requirement on the uniformity of the diffuse reflection screen material is high, and the cost is high; 4. the camera needs to calibrate the distortion and the pixel size again when the position of the camera and the position of the laser module are moved every time, and the workload of operators is increased.
SUMMERY OF THE UTILITY MODEL
In view of the above problems, an object of the present invention is to provide a device for measuring the speckle size and the focal length of a collimator lens, which can ensure the accuracy of measurement, save the cost, and reduce the workload of operators.
In order to solve the technical problem, an embodiment of the present invention provides a device for measuring a speckle size and a focal length of a collimating lens, which includes a laser module, a diffuse transmission screen, a motion mechanism, a camera unit and a processor, wherein the camera unit is fixed on a side of the diffuse transmission screen, which is away from the laser module, a lens optical axis of the camera unit is perpendicular to a transmission surface of the diffuse transmission screen, the laser module includes a light source and a collimating lens, speckles projected by the light source pass through the collimating lens and form diffuse transmission on the diffuse transmission screen, the camera unit can collect the speckles on the diffuse transmission screen to obtain a speckle pattern, the processor is configured to calculate a size of the speckles and a focal length of the collimating lens according to the speckle pattern, the laser module is disposed on the motion mechanism, and the motion mechanism can adjust a position of the laser module so that an optical axis of the light source and an optical axis of the lens of the camera unit are aligned with each other On the same axis.
Further, the camera unit comprises a near field camera for capturing a local pattern of the speckles, and the processor is configured to calculate the size of the speckles from the local pattern.
Further, the camera unit further comprises a far-field camera for capturing an overall pattern of the speckles, and the processor is configured to calculate the focal length of the collimating lens from the overall pattern.
Furthermore, the movement mechanism comprises a five-axis movement platform, and the laser module is fixed on the five-axis movement platform.
Further, the five-axis motion platform comprises a base, a lifting screw rod motion mechanism, a supporting plate, a Y-axis moving platform, an X-axis moving platform and a fixing plate, the lifting screw rod movement mechanism is arranged on the base, the support plate is connected with the output end of the lifting screw rod movement mechanism, the lifting screw rod motion mechanism can drive the supporting plate to move up and down along the Z-axis direction, the Y-axis moving platform is arranged on the supporting plate, the X-axis moving platform is arranged on the Y-axis moving platform, the fixed plate is arranged on the X-axis moving platform, the Y-axis moving platform can drive the X-axis moving platform to move along the Y-axis direction, the X-axis moving platform can drive the fixed plate to move along the X-axis direction, the laser module is fixed on the fixed plate, and the fixed plate can rotate around an X axis and a Y axis.
Furthermore, the motion mechanism further comprises a linear motion platform, the five-axis motion platform is fixed on the linear motion platform, and the linear motion platform can drive the five-axis motion platform to move along the optical axis direction of the light source.
Further, the linear motion platform includes the guide rail seat, sets up guide rail and connection on the guide rail seat are in on the guide rail and with the slider of guide rail adaptation, the guide rail is followed the optical axis direction of light source extends, five-axis motion platform is fixed on the slider.
Further, speckle size and collimating mirror focus measuring device still includes the mount, the mount with laser module interval sets up, the mount has the cavity, the camera unit is fixed in the cavity, the mount orientation laser module one side is provided with diffuse transmission screen, the camera unit with diffuse transmission screen is just right.
Further, the light source includes a plurality of vertical cavity surface emitting lasers arranged to form an array.
Further, the diffuse transmission screen is made of a diffuse transmission material.
Further, the diffuse transmission screen is a diffuse transmission film or a diffuse transmission white board.
The utility model has the beneficial effects that: according to the utility model, the laser module is fixed on the movement mechanism, and the position of the laser module can be adjusted through the movement mechanism, so that the optical axis of the light source and the optical axis of the lens of the camera unit are positioned on the same axis and are vertical to the transmission surface of the diffuse transmission screen, thereby avoiding the occurrence of calculation deviation and ensuring the accuracy of measurement; in addition, the utility model adopts the diffuse transmission screen, and compared with the related technology which adopts the diffuse reflection screen with higher requirement on uniformity, the cost can be saved; and because the position of the camera unit is fixed and the distance between the camera unit and the diffuse transmission screen is kept unchanged, the lens can be prevented from being replaced, the distortion and the pixel size can be prevented from being calibrated again after the camera is moved, and the workload of operators is reduced.
Drawings
Fig. 1 is a schematic structural diagram of a collimator focal length measuring device provided in the related art;
FIG. 2 is a schematic diagram of an optical path of the device for measuring the speckle size and the focal length of the collimator lens provided by the utility model;
FIG. 3 is a schematic view of the overall structure of the device for measuring the speckle size and the focal length of the collimator lens provided by the utility model;
fig. 4 is a schematic structural diagram of the five-axis motion platform in fig. 3.
In the drawings, each reference numeral denotes:
10. a laser module; 20. a diffuse transmission screen; 31. a five-axis motion platform; 311. a base; 312. a lifting screw rod movement mechanism; 313. a support plate; 314. a Y-axis moving platform; 315. an X-axis moving platform; 316. a fixing plate; 32. a linear motion platform; 321. a guide rail seat; 322. a guide rail; 323. a slider; 40. a camera unit; 41. a near field camera; 42. a far-field camera; 50. a fixed mount; 51. a cavity.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present invention in its various embodiments. However, the technical solution claimed in the present invention can be implemented without these technical details and various changes and modifications based on the following embodiments.
Referring to fig. 2 and 3, the embodiment provides a speckle size and collimator focal length measuring device, including a laser module 10, a diffuse transmission screen 20, a motion mechanism, a camera unit 40 and a processor, where the camera unit 40 is in communication connection with the processor, the camera unit 40 is fixed on a side of the diffuse transmission screen 20 away from the laser module 10, a lens optical axis of the camera unit 40 is perpendicular to a transmission surface of the diffuse transmission screen 20, and the laser module 10 and the camera unit 40 are respectively disposed on two opposite sides of the diffuse transmission screen 20.
The laser module 10 includes a light source for projecting speckles and a collimating lens. Speckle is one of the projection patterns of the light source, and in addition, the projection pattern of the light source includes patterns such as blocks, crosses, stripes, and specific symbols. The light source of the present embodiment includes a plurality of vertical cavity surface emitting lasers arranged to form an array, which may be a regular array or an irregular array.
The speckles projected by the light source form diffuse transmission through the collimating lens and on the diffuse transmission screen 20, the diffuse transmission is dispersed at the diffuse transmission screen 20 when the speckles projected by the laser module 10 pass through the diffuse transmission screen 20, and no regular transmission exists macroscopically, at the moment, the camera unit 40 can collect the speckles on the diffuse transmission screen 20 to acquire speckle patterns, and the processor is used for calculating the size of the speckles and the focal length of the collimating lens according to the speckle patterns.
The laser module 10 of this embodiment sets up on the motion, thereby the motion can adjust the position of laser module 10 and make the optical axis of light source and the camera unit 40's camera lens optical axis be in on the same axis, and because the camera unit 40's camera lens optical axis is perpendicular with the transmission plane of diffuse transmission screen 20, therefore the optical axis of light source is also perpendicular with the transmission plane of diffuse transmission screen 20 to avoid appearing the calculation deviation, guarantee measuring accuracy.
In this embodiment, since the position of the camera unit 40 is fixed and the distance from the diffuse transmission screen 20 is kept unchanged, lens replacement and re-calibration of distortion and pixel size after moving the camera can be avoided, and the workload of the operator is reduced. Specifically, the camera unit 40 includes a near-field camera 41, the near-field camera 41 may capture a local pattern of speckles on the diffuse transmission screen 20, and the processor calculates the size of the speckles according to the local pattern of the speckles. Further, the camera unit 40 further includes a far field camera 42, the far field camera 42 can capture an overall pattern of speckles, and the processor calculates the focal length of the collimator lens according to the overall pattern of speckles. It should be noted that, when debugging the device, it is necessary to ensure that the distances between the near-field camera 41 and the far-field camera 42 and the diffuse transmission screen 20 are constant, and after calibrating the distances between the near-field camera 41 and the far-field camera 42 and the diffuse transmission screen 20, the near-field camera 41 and the far-field camera 42 are kept still, so that consistency of measurement results can be ensured.
In one embodiment, the motion mechanism includes a five-axis motion platform 31, and the laser module 10 is fixed on the five-axis motion platform 31. Specifically, the directions of the X axis, the Y axis and the Z axis are defined as shown in fig. 3, the X axis direction is the optical axis direction of the light source, the five-axis motion platform 31 includes a base 311, a lifting screw motion mechanism 312, a support plate 313, a Y axis motion platform 314, an X axis motion platform 315 and a fixed plate 316, the lifting screw motion mechanism 312 is installed on the base 311, the support plate 313 is connected with the output end of the lifting screw motion mechanism 312, the lifting screw motion mechanism 312 can drive the support plate 313 to move up and down along the Z axis direction, the Y axis motion platform 314 is installed on the support plate 313, the X axis motion platform 315 is installed on the Y axis motion platform 314, the fixed plate 316 is installed on the X axis motion platform 315, the Y axis motion platform 314 can drive the X axis motion platform 315 to move along the Y axis direction, the X axis motion platform 315 can drive the fixed plate 316 to move along the X axis direction, the laser module 10 is fixed on the fixed plate 316, the fixed plate 316 is rotatable about the X-axis and the Y-axis. The structure enables the laser module 10 to have freedom degree of movement in five directions, so that an operator can conveniently and accurately adjust the position of the laser module 10, zero-order speckle points of the laser module 10 are coaxial with the optical axis of the lens of the camera unit 40, and the accuracy of measurement is guaranteed.
In addition, in order to further improve the accuracy of measurement, when measuring the focal length of the collimating lens, the laser module 10 can be moved to different positions and measured respectively to obtain the focal length values of the multiple groups of collimating lenses, and then the focal length values of the multiple groups of collimating lenses are averaged. In practical application, the speckle size and collimator focal length measuring device can measure the focal length of the collimator lens in the existing laser module 10, and can also be used for detecting whether the actual focal length of the collimator lens in the laser module 10 in production is accurate or not and detecting the quality problem of the laser module 10.
In one embodiment, the motion mechanism further comprises a linear motion platform 32, the five-axis motion platform 31 is fixed on the linear motion platform 32, and the linear motion platform 32 can drive the five-axis motion platform 31 to move along the optical axis direction of the light source. The linear motion platform 32 can greatly adjust the distance between the laser module 10 and the diffuse transmission screen 20, so as to ensure that the distance between the laser module 10 and the diffuse transmission screen 20 is long as possible, and reduce the system error.
In one embodiment, the linear motion platform 32 includes a rail seat 321, a rail 322 disposed on the rail seat 321, and a slider 323 connected to the rail 322 and adapted to the rail 322, the rail 322 extends along the optical axis direction of the light source, and the five-axis motion platform 31 is fixed on the slider 323. In other possible embodiments, the linear motion platform 32 may also be a screw guide 322 or a belt linear module, and the present embodiment does not limit the specific structure of the linear motion platform 32.
In one embodiment, the device for measuring the speckle size and the focal length of the collimating lens further includes a fixing frame 50, the fixing frame 50 is spaced from the laser module 10, the fixing frame 50 has a cavity 51, the camera unit 40 is fixed in the cavity 51, the diffuse transmission screen 20 is disposed on one side of the fixing frame 50 facing the laser module 10, and the camera unit 40 faces the diffuse transmission screen 20. Because the camera unit 40 and the diffuse transmission screen 20 are both fixed on the fixing frame 50, the distance between the camera unit 40 and the diffuse transmission screen 20 is ensured to be unchanged, the camera unit 40 is accommodated in the cavity 51, and the camera unit 40 can be protected, so that the camera unit 40 is prevented from being polluted or damaged.
In one embodiment, the diffuse transmission screen 20 is made of a diffuse transmission material, specifically, the diffuse transmission screen 20 may be a diffuse transmission film or a diffuse transmission white board, or may be made of other diffuse transmission materials with uniformity satisfying the condition, and the diffuse transmission material has lower requirement on uniformity compared with the diffuse reflection material, so as to save cost. In other possible embodiments, the diffuse transmission screen 20 may also be frosted glass, opal glass, or the like.
The practical operation process of the speckle size and collimating mirror focal length measuring device is as follows: firstly, fixing the near-field camera 41, the far-field camera 42 and the diffuse transmission screen 20 on the fixing frame 50 and keeping the fixing frame stationary, then installing the laser module 10 on a placing station on a motion mechanism, adjusting the motion mechanism to ensure that the optical axis of the light source and the optical axis of the lens of the camera unit 40 are in the same axis and are perpendicular to the transmission surface of the diffuse transmission screen 20, lighting the laser module 10 through an additional driving power supply, transmitting speckles onto the diffuse transmission screen 20, shooting the speckles on the diffuse transmission screen 20 through the near-field camera 41 and the far-field camera 42, and calculating the size of the speckles and the focal length of the collimating lens through a processor.
In summary, the laser module 10 is fixed on the moving mechanism, and the position of the laser module 10 can be adjusted by the moving mechanism, so that the optical axis of the light source and the optical axis of the lens of the camera unit 40 are on the same axis and perpendicular to the transmission surface of the diffuse transmission screen 20, thereby avoiding the occurrence of calculation deviation and ensuring the accuracy of measurement; in addition, the diffuse transmission screen 20 is adopted, and compared with the diffuse reflection screen which has higher requirement on uniformity in the related technology, the cost can be saved; moreover, because the position of the camera unit 40 is fixed, the distance between the camera unit and the diffuse transmission screen 20 is kept unchanged, the lens replacement and the re-calibration of distortion and pixel size after the camera is moved can be avoided, and the workload of operators is reduced. The utility model can be widely applied to 3D sensing technologies such as i-TOF, D-TOF, structured light and the like, can quickly calculate the focal length of the collimating lens of the laser module 10, and ensures the accuracy of the design of the diffractive optical element.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for practicing the utility model, and that various changes in form and details may be made therein without departing from the spirit and scope of the utility model in practice.
Claims (10)
1. A speckle size and collimator focal length measuring device is characterized by comprising a laser module, a diffuse transmission screen, a motion mechanism, a camera unit and a processor, the camera unit is fixed on one side of the diffuse transmission screen, which is far away from the laser module, the optical axis of a lens of the camera unit is vertical to the transmission surface of the diffuse transmission screen, the laser module comprises a light source and a collimating lens, speckles projected by the light source pass through the collimating lens and form diffuse transmission on the diffuse transmission screen, the camera unit can collect the speckles on the diffuse transmission screen to acquire a speckle pattern, the processor is used for calculating the size of the speckles and the focal length of the collimating lens according to the speckle pattern, the laser module is arranged on the moving mechanism, and the moving mechanism can adjust the position of the laser module so that the optical axis of the light source and the optical axis of the lens of the camera unit are on the same axis.
2. The speckle size and collimator focal length measuring device of claim 1, wherein the camera unit comprises a near-field camera for capturing a local pattern of the speckles, the processor for calculating the size of the speckles from the local pattern;
and the camera unit further comprises a far field camera for capturing an overall pattern of the speckles, and the processor is for calculating the focal length of the collimating lens from the overall pattern.
3. The apparatus according to claim 1, wherein the motion mechanism comprises a five-axis motion platform, and the laser module is fixed on the five-axis motion platform.
4. The speckle size and collimator focal length measuring device according to claim 3, wherein the five-axis motion platform comprises a base, a lifting screw motion mechanism, a support plate, a Y-axis motion platform, an X-axis motion platform and a fixed plate, the lifting screw motion mechanism is mounted on the base, the support plate is connected with an output end of the lifting screw motion mechanism, the lifting screw motion mechanism can drive the support plate to move up and down along a Z-axis direction, the Y-axis motion platform is mounted on the support plate, the X-axis motion platform is mounted on the Y-axis motion platform, the fixed plate is mounted on the X-axis motion platform, the Y-axis motion platform can drive the X-axis motion platform to move along a Y-axis direction, the X-axis motion platform can drive the fixed plate to move along the X-axis direction, the laser module is fixed on the fixed plate, and the fixed plate can rotate around an X axis and a Y axis.
5. The device for measuring the speckle size and the focal length of the collimating mirror according to claim 3, wherein the motion mechanism further comprises a linear motion platform, the five-axis motion platform is fixed on the linear motion platform, and the linear motion platform can drive the five-axis motion platform to move along the optical axis direction of the light source.
6. The device for measuring the speckle size and the focal length of the collimating mirror according to claim 5, wherein the linear motion platform comprises a guide rail seat, a guide rail arranged on the guide rail seat, and a slide block connected to the guide rail and adapted to the guide rail, the guide rail extends along the optical axis direction of the light source, and the five-axis motion platform is fixed on the slide block.
7. The device for measuring the speckle size and the focal length of the collimating mirror according to claim 1, further comprising a fixing frame, wherein the fixing frame is spaced from the laser module, the fixing frame has a cavity, the camera unit is fixed in the cavity, the diffuse transmission screen is arranged on one side of the fixing frame facing the laser module, and the camera unit is opposite to the diffuse transmission screen.
8. The apparatus of claim 1, wherein the light source comprises a plurality of VCSELs, and the VCSELs are arranged to form an array.
9. The apparatus according to any one of claims 1 to 8, wherein the diffuse transmission screen is made of a diffuse transmission material.
10. The apparatus according to claim 9, wherein the diffuse transmission screen is a diffuse transmission film or a diffuse transmission white board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121590174.XU CN216132667U (en) | 2021-07-13 | 2021-07-13 | Speckle size and collimating lens focal length measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121590174.XU CN216132667U (en) | 2021-07-13 | 2021-07-13 | Speckle size and collimating lens focal length measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216132667U true CN216132667U (en) | 2022-03-25 |
Family
ID=80767495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121590174.XU Active CN216132667U (en) | 2021-07-13 | 2021-07-13 | Speckle size and collimating lens focal length measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216132667U (en) |
-
2021
- 2021-07-13 CN CN202121590174.XU patent/CN216132667U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102469816B1 (en) | 3D reconstruction system and 3D reconstruction method | |
| CN108871207B (en) | Photogrammetry reference ruler length calibration device and use method | |
| CN108332708A (en) | Laser leveler automatic checkout system and detection method | |
| KR102461481B1 (en) | Projection of structured light for a mirror surface | |
| CN102102989B (en) | Vortex phase plate-based laser beam reference calibration method and device | |
| CN105182353B (en) | A kind of non-contact laser distance meter and measurement method | |
| KR20200115379A (en) | Optical measurement apparatus and method | |
| CN114001666A (en) | Terahertz scanning imaging device suitable for large-range complex curved surface object | |
| CN116381655A (en) | Detection device | |
| CN114544151A (en) | Lens transmittance detection device and detection method thereof | |
| CN216132667U (en) | Speckle size and collimating lens focal length measuring device | |
| CN108931185B (en) | Detection device and detection method of optical-mechanical module | |
| WO2007001327A2 (en) | Apparatus and methods for scanning conoscopic holography measurements | |
| CN117092814A (en) | Adjusting device and method for optical system of poloxamer | |
| CN108709509B (en) | Contour camera, matched oversized-diameter revolving body workpiece non-contact caliper and non-contact revolving body measuring method | |
| CN116342711A (en) | XR virtual imaging position calibration module, assembly method and calibration method | |
| CN114858097B (en) | Laser radar rotating mirror included angle measuring method and measuring device | |
| CN110425987A (en) | A kind of penetrability laser thickness gauge | |
| CN115014204A (en) | Geometric center positioning measurement method and system for near-to-eye display equipment | |
| CN108971752A (en) | Automatic identification and the welding equipment of welding position can be grabbed | |
| CN104991421B (en) | Drawing apparatus | |
| CN110726376A (en) | Depth precision testing device and method for depth device | |
| CN112304253A (en) | Non-contact measurement and adjustment method for parallelism and coaxiality of optical mirror | |
| CN218158570U (en) | Angle-adjustable light path structure for obtaining parallel light | |
| CN114485476B (en) | Wafer measurement equipment, system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |