An optical system and a 3D measurement device
By controlling the polarization of the beam through a polarization adjustment module and a polarization module, optical path folding is achieved, which solves the contradiction between the size and accuracy of 3D measurement equipment and improves the measurement performance of the equipment in confined spaces.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU HIKROBOT TECH CO LTD
- Filing Date
- 2025-08-01
- Publication Date
- 2026-07-31
AI Technical Summary
Existing 3D measurement equipment has a large working volume due to its optical path design, which creates a contradiction between size and measurement performance, making it difficult to perform high-precision measurements in confined spaces.
The polarization direction of the beam is controlled by a polarization control module and a polarization module, which realizes optical path folding, reduces the size of the optical system, and filters out unpolarized stray light through the polarization module, thereby improving the signal-to-noise ratio.
It significantly reduces the working size of 3D measurement equipment, improves measurement accuracy and signal-to-noise ratio, expands application scenarios, and is suitable for small and compact spaces.
Smart Images
Figure CN224580887U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of machine vision technology, and in particular to an optical system and a 3D measurement device. Background Technology
[0002] 3D measurement equipment is a high-precision, non-contact measurement device used in industrial automation, defect detection, scientific research, and other fields. 3D measurement typically involves projecting a light beam from a light source onto the object being measured, acquiring an image of the object, and then combining this image with the object's relative motion to perform measurements. Common 3D measurement devices include laser displacement sensors, 3D laser profile sensors, line laser stereo cameras, and structured light stereo cameras.
[0003] Taking a 3D laser contour sensor as an example, such as Figure 1 The diagram shows the operation of a traditional 3D laser contour sensor. The laser emitter 100 emits a linear laser beam that is projected onto the surface of the object being measured 200. The lens assembly 300 captures the laser contour line formed by the reflection of the laser beam onto the surface of the object being measured 200 and projects it onto the image receiver 400. Each pixel on the image receiver 400 corresponds to a specific position on the laser beam. By measuring the position of the reflected light on the image receiver 400, the distance from the image receiver 400 to that position can be calculated. Then, through the relative motion between the linear laser contour sensor and the object being measured 200, data is continuously collected, and the complete three-dimensional contour information of the object being measured 200 is recovered through data processing and synthesis.
[0004] It is evident that related 3D measurement equipment typically employs a longer optical path to accommodate a larger measurement range. However, this optical path design results in a larger working volume for the 3D measurement equipment, which to some extent creates a constraint between the working volume and measurement performance of the 3D measurement equipment. Utility Model Content
[0005] The purpose of this utility model embodiment is to provide an optical system and a 3D measurement device, so as to improve the measurement accuracy of the 3D measurement device while reducing its working size. The specific technical solution is as follows:
[0006] In a first aspect, an optical system is provided, the optical system including a polarization control module and a polarization module. A light beam incident on the optical system in a first polarization direction is reflected by the polarization module and incident on the polarization control module in a first direction, and is reflected by the polarization control module in a second direction and transmitted through the polarization module, wherein the first direction is opposite to the second direction.
[0007] The polarization module is used to reflect a beam of light with a first polarization direction and transmit a beam of light with a second polarization direction.
[0008] The polarization control module is used to adjust the polarization direction of the light beam from the first polarization direction to the second polarization direction.
[0009] In one possible implementation, the polarization control module includes a polarization control unit and a reflection unit; a light beam incident on the polarization control module is incident on the reflection unit along the first direction via the polarization control unit, and is incident on the polarization control unit along the second direction via the reflection unit.
[0010] The polarization control unit is used to adjust the polarization direction of the light beam incident along the first direction from the first polarization direction to the third polarization direction, and to adjust the polarization direction of the light beam incident along the second direction from the fourth polarization direction to the second polarization direction, wherein the third polarization direction and the fourth polarization direction are opposite.
[0011] The reflecting unit is used to adjust the polarization direction of the light beam from the third polarization direction to the fourth polarization direction.
[0012] In one possible implementation, the polarization control unit is a quarter-wave plate, and the angle between the direction of the fast axis of the quarter-wave plate and the first polarization direction is 45°.
[0013] In one possible implementation, the polarization modulation unit is a spatial light modulator.
[0014] In one possible implementation, the polarization module is a polarizer, an optical diffraction element, or a superlens.
[0015] In one possible implementation, the first polarization direction is perpendicular to the second polarization direction.
[0016] A second aspect of this utility model provides a 3D measurement device, including a light-emitting module, an image acquisition module, and an optical system as described in the first aspect above, wherein the polarization control module, the polarization module, and the image acquisition module are arranged sequentially along a second direction;
[0017] The light-emitting module is used to emit a light beam with a first polarization direction toward the surface to be tested, and the light beam is incident on the optical system after being reflected by the surface to be tested;
[0018] The image acquisition module is used to receive image data from the light beam emitted by the optical system.
[0019] In one possible implementation, the image acquisition module includes a lens and an image sensor;
[0020] The lens is used to focus the light beam emitted from the optical system onto the image sensor;
[0021] The image sensor is used to generate image data of the object under test based on the received light beam.
[0022] In one possible implementation, the 3D measuring device further includes a housing and a connector; the light-emitting module, the optical system, and the image acquisition module are fixed inside the housing via the connector.
[0023] In one possible implementation, the light-emitting module, the optical system, and the image acquisition module are arranged sequentially along the second direction.
[0024] In one possible implementation, the lens is a SAM lens.
[0025] In one possible implementation, the light-emitting module is a point laser emitting module, and the 3D measuring device is a laser displacement sensor; or
[0026] The light-emitting module is a line laser emitting module, and the 3D measuring device is a 3D laser contour sensor or a line laser stereo camera; or
[0027] The light-emitting module is a structured light emitting module, and the 3D measurement device is a structured light stereo camera.
[0028] The beneficial effects of this utility model embodiment are as follows:
[0029] This invention provides an optical system and a 3D measurement device. Since a beam of light with a first polarization direction is reflected by a polarization module and incident along a first direction onto a polarization control module, and then reflected again by the polarization control module along a second direction onto the polarization module, and since the first and second directions are opposite, this indicates that the beam undergoes optical path folding between the polarization module and the polarization control module. Furthermore, since the polarization control module can adjust the beam's polarization direction from the first polarization direction to the second polarization direction, and the polarization module can only transmit beams with the second polarization direction, the beam with the first polarization direction, after being incident along the first direction onto the polarization control module, can be adjusted to a beam with the second polarization direction, and thus exit from the polarization module along the second direction. By controlling the beam polarization state through the polarization module and the polarization control module, optical path folding is achieved. Compared to an optical system without optical path folding, the volume of the optical system can be reduced. When this optical system is applied to a 3D measurement device, the working volume of the 3D measurement device can be significantly reduced. Furthermore, when the original beam emitted by the 3D measurement device is a linearly polarized beam, the polarization direction of the linearly polarized beam can be adjusted by the polarization module and polarization control module. This can filter out unpolarized ambient stray light, improve the signal-to-noise ratio, and enable the 3D measurement device to obtain a high signal-to-noise ratio light image through the optical system. This improves measurement accuracy and makes it more suitable for small and compact spaces, thus expanding the application scenarios.
[0030] Of course, implementing any product or method of this utility model does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description
[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings.
[0032] Figure 1 A schematic diagram of the operation of a traditional 3D laser contour sensor;
[0033] Figure 2 A schematic diagram of the first structure of the optical system provided in an embodiment of this utility model;
[0034] Figure 3 A first optical path diagram of an optical system provided for an embodiment of this utility model;
[0035] Figure 4 This is a schematic diagram of a second structure of the optical system provided in an embodiment of the present invention;
[0036] Figure 5A second optical path diagram of the optical system provided in this embodiment of the present invention;
[0037] Figure 6 This is a schematic diagram of a first structure of the 3D measuring device provided in an embodiment of the present utility model;
[0038] Figure 7 A first optical path diagram of the 3D measuring device provided in this embodiment of the present invention;
[0039] Figure 8 A second optical path diagram of the 3D measuring device provided in this embodiment of the present invention;
[0040] Figure 9 This is a second structural schematic diagram of the 3D measuring device provided in an embodiment of the present invention;
[0041] The meaning of each reference numeral in the attached figures will be explained below:
[0042] 100—Laser emitter; 200—Object under test; 300—Lens assembly; 400—Image receiver; 10—Polarization control module; 20—Polarization module; 101—Polarization control unit; 102—Reflection unit; 30—Light emission module; 40—Image acquisition module; 50—Object under test; 401—Lens; 402—Image sensor; 60—Housing. Detailed Implementation
[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art based on the present utility model are within the protection scope of the present utility model.
[0044] When using 3D measurement equipment, a light beam is typically projected from a light source onto the object being measured to capture an image. This image is then combined with the object's relative motion to perform the measurement. A fixed baseline distance exists between the light source and the image sensor, and the optical path length is also subject to certain limitations. Taking a 3D laser contour sensor as an example... Figure 1As shown, a laser beam shines directly onto the surface of the object under test 200. The imaging system (i.e., lens assembly 300 and image receiver 400) is tilted, with an angle θ between it and the laser optical axis. The linear laser emitted by the laser emitter 100 has a line length along the X-axis, while the object under test 200 moves along the Y-axis. The change in height in the Z-axis direction is represented by a change in pixel coordinates in the image receiver 400. Through a laser contour sensor calibrated with intrinsic parameters, the change in object height (Z-axis) can be indirectly measured based on the change in pixel coordinates in the image receiver 400, thus obtaining the contour information of the object under test 200. The lens assembly 300 of the laser contour sensor typically has a fixed depth of field range; only when the object under test 200 is within this depth of field range can the reflected light be clearly received by the image receiver 400.
[0045] To ensure that the measured object 200 is within the depth of field, allowing the laser beam to pass through the lens assembly 300 and be clearly imaged on the image receiver 400, the optical path distance between the measured object 200 and the lens assembly 300 is relatively large in some distant scenes, resulting in a larger working volume for the laser contour sensor. However, directly reducing the optical path distance between the measured object 200 and the lens assembly 300 might lead to an excessively short optical path, causing reflected light to deviate from the focal plane, resulting in a blurred spot or insufficient signal strength, thus affecting measurement accuracy.
[0046] Based on this, in order to improve the measurement accuracy of 3D measuring equipment while reducing its working size, a first aspect of this utility model provides an optical system, such as... Figure 2 The diagram shown is a first structural schematic of the optical system provided in this embodiment of the present invention, including a polarization control module 10 and a polarization module 20.
[0047] The polarization adjustment module 10 can consist of one or more optical elements. The polarization adjustment module 10 has a reflection function and can adjust the polarization direction of the light beam from a first polarization direction to a second polarization direction. The polarization module 20 can also consist of one or more optical elements. When the polarization module 20 consists of one optical element, it can be a polarizer, an optical diffraction element, a superlens, or other optical elements used to reflect a light beam in the first polarization direction and transmit a light beam in the second polarization direction. This embodiment of the invention does not limit this. When the polarization module 20 consists of multiple optical elements, the polarization module can change the propagation direction of the received light beam in the first polarization direction, so that the incident and exit directions of the light beam in the first polarization direction are different, effectively reflecting the light beam in the first polarization direction. It can also keep the propagation direction of the received light beam in the second polarization direction unchanged, so that the incident and exit directions of the light beam in the second polarization direction are the same, effectively transmitting the light beam in the second polarization direction.
[0048] A light beam incident on the optical system in a first polarization direction is reflected by the polarization module 20 and enters the polarization adjustment module 10 along the first direction, and is reflected by the polarization adjustment module 10 along the second direction and transmitted from the polarization module 20. The first direction and the second direction are opposite, and the first polarization direction and the second polarization direction are different.
[0049] It is understandable that if the angle between the first polarization direction and the second polarization direction is less than 90 degrees, the polarization module can only reflect most of the beam in the first polarization direction and project most of the beam in the second polarization direction. It can be assumed that the beam in the first polarization direction has leakage in the polarization module, and the beam in the second polarization direction will be lost when passing through the polarization module, which may lead to a decrease in measurement accuracy.
[0050] Therefore, to improve measurement accuracy, in one possible implementation, the first polarization direction is perpendicular to the second polarization direction. For example, the first polarization direction is either horizontal linear polarization or vertical linear polarization, and the second polarization direction is the other of the two. Specifically, assuming the first polarization direction is horizontal linear polarization, then the second polarization direction is vertical linear polarization. Linear polarization refers to the electric field vector of light oscillating in only one direction, and the direction of oscillation remains unchanged. The electric field vector of horizontally linearly polarized light oscillates in a horizontal plane, while the electric field vector of vertically linearly polarized light oscillates in a plane perpendicular to the horizontal plane. The horizontal plane can be predetermined; in one possible embodiment, a plane parallel to the ground can be referred to as the horizontal plane.
[0051] like Figure 3The diagram shows a first optical path of the optical system provided in this embodiment of the present invention. Assuming the first polarization direction is horizontal linear polarization, the polarization module cannot transmit horizontally linearly polarized light beams, but can only transmit vertically linearly polarized light beams. When the light beam is incident on the polarization module 20, it is reflected by the polarization module 20 and incident along the first direction onto the polarization adjustment module 10, and then reflected by the polarization adjustment module 10 and incident along the second direction onto the polarization module 20. When the polarization adjustment module receives the horizontally linearly polarized light beam reflected by the polarization module, the polarization adjustment module 10 adjusts the polarization direction of the light beam from horizontal linear polarization to vertical linear polarization. At this time, the polarization direction of the light beam exiting from the polarization adjustment module 10 along the second direction to the polarization module 20 is vertically linearly polarized and can exit through the polarization module 20.
[0052] In this embodiment of the invention, the beam with the first polarization direction is reflected by the polarization module and incident along the first direction onto the polarization control module, and then reflected by the polarization control module and incident along the second direction onto the polarization module. Since the first and second directions are opposite, this indicates that the beam undergoes optical path folding between the polarization module and the polarization control module. Furthermore, since the polarization control module can adjust the beam's polarization direction from the first polarization direction to the second polarization direction, and the polarization module can only transmit beams with the second polarization direction, the beam with the first polarization direction, after being incident along the first direction onto the polarization control module, can be adjusted to a beam with the second polarization direction and thus exit the polarization module along the second direction. By controlling the beam polarization state through the polarization module and the polarization control module, optical path folding is achieved. Compared to an optical system without optical path folding, the volume of the optical system can be reduced. When this optical system is applied in a 3D measurement device, the working volume of the 3D measurement device can be significantly reduced. Furthermore, when the original beam emitted by the 3D measurement device is a linearly polarized beam, the polarization direction of the linearly polarized beam can be adjusted by the polarization module and polarization control module. This can filter out unpolarized ambient stray light, improve the signal-to-noise ratio, and enable the 3D measurement device to obtain a high signal-to-noise ratio light image through the optical system. This improves measurement accuracy and makes it more suitable for small and compact spaces, thus expanding the application scenarios.
[0053] It is understood that, in one possible implementation, the polarization control module 10 may consist of an optical element, such as a Faraday rotator or a reflective half-wave plate.
[0054] In one possible implementation, the polarization control module may also be composed of multiple optical elements. For example, such as... Figure 4 As shown, Figure 4This is a schematic diagram of a second structure of an optical system provided in an embodiment of the present invention. The polarization control module 10 includes a polarization control unit 101 and a reflection unit 102. A light beam incident on the polarization control module 10 is incident on the reflection unit 102 along a first direction via the polarization control unit 101, and is incident on the polarization control unit 101 along a second direction via the reflection of the reflection unit 102.
[0055] The polarization adjustment unit 101 is used to adjust the polarization direction of a beam incident along a first direction from a first polarization direction to a third polarization direction, and to adjust the polarization direction of a beam incident along a second direction from a fourth polarization direction to a second polarization direction. The reflection unit 102 is used to adjust the polarization direction of the beam from a third polarization direction to a fourth polarization direction.
[0056] The third polarization direction is opposite to the fourth polarization direction. The third polarization direction is either left-handed circular polarization or right-handed circular polarization, and the fourth polarization direction is either left-handed circular polarization or right-handed circular polarization. For example, if the third polarization direction is left-handed circular polarization, then the second polarization direction is right-handed circular polarization.
[0057] like Figure 5 The diagram shows a second optical path of the optical system provided in this embodiment. Assuming the first polarization direction is horizontal linear polarization, the polarization module cannot transmit horizontally linearly polarized light beams, only vertically polarized light beams. When light is incident on the polarization module 20, it is reflected by the polarization module 20 and incident on the polarization adjustment unit 101 along the first direction. The polarization adjustment unit 101 adjusts the polarization direction of the light beam from horizontal linear polarization to right-hand circular polarization before it exits to the reflection unit 102. After reflection by the reflection unit 102, the polarization direction of the light beam is adjusted from right-hand circular polarization to left-hand circular polarization and reflected along the second direction to the polarization adjustment unit 101. The polarization adjustment unit 101 adjusts the polarization direction of the light beam from left-hand circular polarization to vertical linear polarization before it exits along the second direction to the polarization module 20. At this point, the polarization direction of the light beam is vertically polarized and can exit through the polarization module 20.
[0058] Compared to the method where the polarization control module directly adjusts the beam in the first polarization direction to the beam in the second polarization direction and increases the size of the optical system by using multiple reflectors, the present invention, by setting the reflection unit in the first direction of the polarization control unit, further achieves beam folding in the polarization control unit, thereby reducing the size of the optical system.
[0059] The polarization control unit can consist of a single optical element or multiple optical elements. For example, when linearly polarized light is incident on the fast axis at 45°, a quarter-wave plate can convert the linearly polarized light into circularly polarized light. Based on this, in one possible implementation, the polarization control unit employs a quarter-wave plate, where the angle between the direction of the fast axis of the quarter-wave plate and the first polarization direction is 45°.
[0060] By employing the embodiments of this utility model, a quarter-wave plate can simply and efficiently achieve the conversion between linearly polarized beams and circularly polarized beams. Furthermore, the quarter-wave plate has low cost and small size, thereby reducing the cost and size of the optical system.
[0061] In order for the polarization control unit to precisely adjust the polarization direction of the beam, one possible implementation is that the polarization control unit can also be a spatial light modulator.
[0062] In one possible implementation, the polarization module 20 is a polarizer and the polarization adjustment unit 101 is a quarter-wave plate. In order for the polarizer to both receive the light beam reflected by the object under test and reflect the light beam in the first polarization direction along the first direction, there is a preset angle between the polarizer and the quarter-wave plate. The size of the preset angle can be set according to the requirements, and this embodiment of the present invention does not limit it.
[0063] It is understood that the optical system provided in this embodiment of the present invention can be applied not only to 3D laser contour sensors but also to 3D measurement devices, such as laser displacement sensors, line laser stereo cameras, and structured light stereo cameras. The form of the light beam may also differ in different 3D measurement devices. For example, when the optical system provided in this embodiment of the present invention is applied to a laser displacement sensor, the light beam is a point laser beam or a line laser beam; when the optical system is applied to a 3D laser contour sensor or a line laser stereo camera, the light beam is a line laser beam; and when the optical system is applied to a structured light stereo camera, the light beam is structured light, such as in a monocular structured light stereo camera or a binocular structured light stereo camera.
[0064] Corresponding to the first aspect mentioned above, the second aspect of this utility model embodiment provides a 3D measurement device, such as... Figure 6 The diagram shown is a first structural schematic of the 3D measuring device provided in this embodiment of the present invention, including a light-emitting module 30, an image acquisition module 40 and an optical system as described in the first aspect above, wherein the polarization control module 10, the polarization module 20 and the image acquisition module 40 are arranged sequentially along the second direction;
[0065] The light-emitting module 30 is used to emit a laser beam with a first polarization direction toward the surface to be tested. The laser beam is reflected by the surface to be tested and then incident on the optical system. The image acquisition module 40 is used to receive the laser beam emitted by the optical system to obtain image data.
[0066] In this embodiment, either direct or oblique beam measurement can be used. In the case of direct beam measurement, the laser emission direction of the light-emitting module 30 is parallel to the normal of the surface of the object to be measured; in the case of oblique beam measurement, there is a certain angle between the laser emission direction of the light-emitting module 30 and the normal of the surface of the object to be measured, and the angle is acute.
[0067] like Figure 7 The diagram shows the first optical path of the 3D measuring device provided in this embodiment of the present invention. Assuming a direct-light measurement is used, the first polarization direction is horizontal linear polarization. The laser beam emitted by the light-emitting module 30 is reflected by the surface of the object to be measured 50 and then incident on the polarization module 20. After being reflected by the polarization module 20, it is incident on the polarization control unit 101 along the first direction. The polarization control unit 101 adjusts the polarization direction of the laser beam from horizontal linear polarization to right-hand circular polarization and then emits it to the reflection unit 102. After being reflected by the reflection unit 102, the polarization direction of the laser beam is adjusted from right-hand circular polarization to left-hand circular polarization and reflected along the second direction to the polarization control unit 101. The polarization control unit 101 adjusts the polarization direction of the laser beam from left-hand circular polarization to vertical linear polarization and then emits it along the second direction to the polarization module 20. At this time, the polarization direction of the laser beam is vertical linear polarization. The laser beam can be emitted through the polarization module 20 to the image acquisition module 40, thereby obtaining image data.
[0068] In this embodiment of the invention, the laser beam with a first polarization direction is reflected by the polarization module and incident along the first direction onto the polarization control module, and then reflected by the polarization control module and incident along the second direction onto the polarization module. Since the first and second directions are opposite, this indicates that the laser beam undergoes optical path folding between the polarization module and the polarization control module. Furthermore, since the polarization control module can adjust the polarization direction of the laser beam from the first polarization direction to the second polarization direction, and the polarization module can only transmit laser beams with the second polarization direction, the laser beam with the first polarization direction, after being incident along the first direction onto the polarization control module, can be adjusted to a laser beam with the second polarization direction and thus exit the polarization module along the second direction. By controlling the polarization state of the laser beam through the polarization module and the polarization control module, optical path folding is achieved. Compared to an optical system without optical path folding, the volume of the optical system can be reduced. When this optical system is applied in a 3D measurement device, the working volume of the 3D measurement device can be significantly reduced. Furthermore, when the original laser beam emitted by the 3D measurement device is a linearly polarized laser beam, the polarization direction of the linearly polarized laser beam can be adjusted by the polarization module and polarization control module. This can filter out unpolarized ambient stray light, improve the signal-to-noise ratio, and enable the 3D measurement device to obtain a laser line image with a high signal-to-noise ratio through the optical system. This improves measurement accuracy and makes it more suitable for small and compact spaces, thus expanding the application scenarios.
[0069] In the case of direct-light measurement, in order to reduce the working size of the 3D measurement equipment, the light-emitting module, optical system, and image acquisition module are arranged sequentially along the second direction, such as... Figure 7 As shown, the light-emitting module 30, the reflection unit 102, the polarization control unit 101, the polarization module 20, and the image acquisition module are arranged sequentially along the second direction.
[0070] In one possible implementation, the image acquisition module includes a lens and an image sensor. The lens is used to focus the laser beam emitted from the optical system onto the image sensor, and the image sensor is used to convert the received laser beam into image data of the object under test.
[0071] like Figure 8 The diagram shown is a second optical path diagram of the 3D measuring device provided in this embodiment of the present invention. Assuming the first polarization direction is horizontal linear polarization, the laser beam emitted by the light-emitting module 30 is reflected by the surface of the object to be measured 50 and then incident on the polarization module 20. After being reflected by the polarization module 20, it is incident on the polarization control unit 101 along the first direction. The polarization control unit 101 adjusts the polarization direction of the laser beam from horizontal linear polarization to right-hand circular polarization and then emits it to the reflection unit 102. After being reflected by the reflection unit 102, the polarization direction of the laser beam is adjusted from right-hand circular polarization to left-hand circular polarization and reflected along the second direction to the polarization control unit 101. The polarization control unit 101 adjusts the polarization direction of the laser beam from left-hand circular polarization to vertical linear polarization and then emits it along the second direction to the polarization module 20. At this time, the polarization direction of the laser beam is vertical linear polarization. The laser beam can be emitted through the polarization module 20 to the lens 401. The lens 401 focuses the laser beam emitted by the optical system onto the image sensor 402. The image sensor 402 generates image data of the object to be measured based on the received laser beam.
[0072] Lens 401 can be a SAM lens or any other lens besides a SAM lens; this embodiment of the present invention does not limit this. Image sensor 402 can be a CCD (Charge Coupled Device) sensor or any other image sensor; this embodiment of the present invention does not limit this.
[0073] However, ordinary lenses are only suitable for static measurement of planar targets, and their detection efficiency is low for dynamic, large-area, or complex curved surfaces, requiring multiple lens changes or parameter adjustments. To improve the detection efficiency of the laser contour sensor, in one possible implementation, lens 401 is a SAM lens, enabling the 3D measurement device to accurately measure dynamic objects, large-area objects, or objects with complex curved surfaces. Furthermore, because the SAM lens has high-quality imaging performance, it can accurately focus the laser beam onto the image sensor 402, forming a clear laser line image on the image sensor 402.
[0074] The image data acquired by the image sensor is then transmitted to the image processing system to perform analysis steps such as 3D contour reconstruction and depth calculation.
[0075] It is understandable that, as the light-emitting module, optical system, and image acquisition module are core components of 3D measurement equipment, they may be damaged by external physical impacts, vibrations, or pressure. Therefore, to ensure the stable operation of the core components of the 3D measurement equipment, in one possible implementation, such as... Figure 9 The diagram shown is a second structural schematic of the 3D measuring device provided in this embodiment of the present invention. In addition to the above, the 3D measuring device also includes... Figure 7 In addition to the components shown, the system also includes a housing 60 and a connector. The light-emitting module 30, the optical system, and the image acquisition module 40 are fixed inside the housing 60 by the connector. Figure 9 Not shown in the image.
[0076] There may be one or more connectors, and the connectors may be bolts, studs, etc. This utility model embodiment does not limit the type of connector.
[0077] Understandably, in order to allow the light beam emitted from the surface of the object under test to enter the image acquisition module, the housing 60 is pre-set with a light-transmitting hole, through which the light beam emitted from the surface of the object under test can enter the polarization module 20 of the 3D measurement device.
[0078] The 3D measuring device provided in this embodiment of the invention effectively reduces the device's working volume through a multi-folding design of the optical path, making the device more compact and suitable for space-constrained work environments. Furthermore, by controlling the polarization states and folding the optical path multiple times, a high signal-to-noise ratio light image can be obtained, improving the accuracy of 3D measurement.
[0079] As mentioned above, the optical system provided in this embodiment can be applied not only to 3D laser contour sensors but also to 3D measurement devices, such as laser displacement sensors, line laser stereo cameras, and structured light stereo cameras. It is understood that, in order to achieve different beam forms emitted by different 3D measurement devices, the light-emitting modules in different 3D measurement devices may be different.
[0080] Based on this, in one possible implementation, the light-emitting module is a point laser emitting module, and the 3D measuring device is a laser displacement sensor; or
[0081] The light-emitting module is a line laser emitting module, and the 3D measurement equipment is a 3D laser contour sensor or a line laser stereo camera; or
[0082] The light-emitting module is a structured light emitting module, and the 3D measurement device is a structured light stereo camera.
[0083] By adopting the embodiments of this utility model, the 3D measurement equipment can be applied to different measurement scenarios, thereby improving the applicability of the 3D measurement equipment.
[0084] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0085] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the 3D measurement device embodiments are basically similar to the optical system embodiments, so the description is relatively simple; relevant parts can be referred to the description of the optical system embodiments.
[0086] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.
Claims
1. An optical system characterized by comprising: The optical system includes a polarization control module and a polarization module. A light beam incident on the optical system in a first polarization direction is reflected by the polarization module and enters the polarization control module in the first direction, and is reflected by the polarization control module in the second direction and transmitted through the polarization module. The first direction is opposite to the second direction. The polarization module is used to reflect a beam of light with a first polarization direction and transmit a beam of light with a second polarization direction. The polarization control module is used to adjust the polarization direction of the light beam from the first polarization direction to the second polarization direction.
2. The optical system of claim 1, wherein The polarization control module includes a polarization control unit and a reflection unit; the light beam incident on the polarization control module is incident on the reflection unit along the first direction via the polarization control unit, and is incident on the polarization control unit along the second direction via the reflection unit; The polarization control unit is used to adjust the polarization direction of the light beam incident along the first direction from the first polarization direction to the third polarization direction, and to adjust the polarization direction of the light beam incident along the second direction from the fourth polarization direction to the second polarization direction, wherein the third polarization direction and the fourth polarization direction are opposite. The reflecting unit is used to adjust the polarization direction of the light beam from the third polarization direction to the fourth polarization direction.
3. The optical system of claim 2, wherein, The polarization control unit is a quarter-wave plate, and the angle between the direction of the fast axis of the quarter-wave plate and the first polarization direction is 45°.
4. The optical system of claim 2, wherein, The polarization control unit is a spatial light modulator.
5. The optical system of claim 1, wherein The polarization module is a polarizer, an optical diffraction element, or a superlens.
6. The optical system of claim 1, wherein, The first polarization direction is perpendicular to the second polarization direction.
7. A 3D measuring device, characterized in that It includes a light-emitting module, an image acquisition module, and an optical system as described in any one of claims 1-6, wherein the polarization control module, the polarization module, and the image acquisition module are arranged sequentially along the second direction; The light-emitting module is used to emit a light beam with a first polarization direction toward the surface to be tested, and the light beam is incident on the optical system after being reflected by the surface to be tested; The image acquisition module is used to receive image data from the light beam emitted by the optical system.
8. The 3D measuring device according to claim 7, characterized in that, The image acquisition module includes a lens and an image sensor; the lens and the image sensor are arranged sequentially along the second direction; The lens is used to focus the light beam emitted from the optical system onto the image sensor; The image sensor is used to generate image data of the object under test based on the received light beam.
9. The 3D measuring device according to claim 7, characterized in that, The 3D measuring device also includes a housing and a connector; the light-emitting module, the optical system and the image acquisition module are fixed inside the housing by the connector.
10. The 3D measuring device according to claim 7, characterized in that, The light-emitting module, the optical system, and the image acquisition module are arranged sequentially along the second direction.
11. The 3D measuring device according to claim 8, characterized in that The lens in question is a SAM lens.
12. The 3D measuring device according to claim 7, characterized in that The light-emitting module is a point laser emitting module, and the 3D measuring device is a laser displacement sensor; or The light-emitting module is a line laser emitting module, and the 3D measuring device is a 3D laser contour sensor or a line laser stereo camera; or The light emitting module is a structured light emitting module, and the 3D measuring device is a structured light stereo camera.