TW201435299A - A method and apparatus of profile measurement - Google Patents

Abstract

A system and method for profile measurement based on triangulation involves arrangement of an image acquisition assembly relative to an illumination assembly such that an imaging plane is parallel to a light plane (measurement plane defined by where the light plane impinges on the object), which supports uniform pixel resolution in the imaging plane. The image acquisition assembly includes an imaging sensor having a sensor axis and a lens having a principal axis, wherein the lens axis is offset from the imaging axis.

Description

Method and apparatus for contour measurement Cross-reference to related applications

This application claims US Provisional Application No. 61/732,292 (the '292 application) filed on December 1, 2012, and US Provisional Application No. 61/793,366 (the '366 application) filed on March 15, 2013 )s right. Both the '292 application and the '366 application are hereby fully incorporated herein by reference.

The present invention generally relates to a system for imaging-based contouring and/or dimensional measurement of articles.

This background description is set forth below for the purpose of providing context only. Therefore, to the extent that the background description is not to be taken as a prior art, it is not to be construed as an

Systems for imaging-based profilometry for two-dimensional (2D) and three-dimensional (3D) objects are in widespread use. We can find these imaging-based profilometry systems in many applications ranging from self-measurement, process control, and modeling to guidance.

Among many technical approaches, the most common technique is called triangulation, where a structured light pattern (such as a bright dot, a bright line, a cross, a circle, or a plurality of such) , or a combination thereof, is projected from an angle onto the surface of the object of interest, and an imaging sensor or more than one imaging sensor is used to view the reflected light pattern from different angles. The angular difference will be formed to determine the surface of the object that reflects the light pattern to the light pattern. The basis of the distance from the source. The imaging sensor is typically a camera, but other photosensitive sensors can be used. The most common source of light will be a laser used to create laser dots, lightning rays or other patterns. Other sources that produce similar illumination effects (known as structural lighting) can also be used. A similar arrangement of imaging sensors also applies to situations where the object (eg, the needle) can be avoided while measuring a pattern perpendicular to the plane of another object, such as an ink dispensing needle. Mechanical interference. Uniform area illumination can be used in this situation: orientation (with a predetermined angle of incidence) or non-orientation (ie, cloudy illumination).

This approach (making the imaging sensor at an angle to the illumination plane or the illuminated plane) is well known and well practiced. However, this approach has some improper characteristics. First, the angular difference between the projection of the light or light pattern (from the light source) and the inspection of the light or light pattern reflected by the imaging sensor (referred to as the measurement angle) is critical to the measurement resolution. A known approach using an angle of less than 90 degrees magnifies the size in one portion of the imaging plane and reduces the size in another portion of the imaging plane; however, this situation causes a reduction in overall image resolution. Second, the measurement angle also determines the complexity of the mathematical model in the triangulation calculation. For measurement angles less than 90 degrees, the model is complex in that it involves at least a triangular transformation.

Accordingly, there is a need for an improved profile and size measurement system and method that overcomes one or more of the problems set forth above.

The foregoing discussion is intended to be illustrative only and is not to be construed as a

A specific example in accordance with the teachings of the present invention provides a system and method for contouring and dimensioning an object that relies on an offset image acquisition assembly having at least a shifted lens, at least in a light plane or a light plane and an imaging plane The parallelism of the captured image is characteristic.

In a specific example, a system for determining the contour of an object is provided System. The system includes a lighting assembly, an image acquisition assembly, and a data unit. The illumination assembly is configured to project a light plane onto an exterior surface of one of the objects. The image acquisition assembly includes an imaging sensor and a lens. The imaging sensor is configured to capture an image of an imaging plane, wherein the imaging plane is substantially parallel to the optical plane and is located in the optical plane. The lens has a major axis and is disposed between the light plane and the imaging sensor. The lens is positioned relative to the imaging sensor such that the major axis is offset from a sensor axis, wherein the sensor axis is substantially perpendicular to the imaging sensor and passes through the imaging sensor One center. The data unit (typically a computer having one display, or a single display) is configured to receive the captured image and use at least the captured image to form the contour.

A method of forming a contour of an outer surface of an object is also presented.

In another embodiment, a method is provided for determining a planar feature (such as a 2D projection size or shape) of an object when the main axis (which is perpendicular to an object and passing through the center of the object) is occupied by another object. system. The system includes a lighting assembly, an image acquisition assembly, and a data unit. The illumination assembly is configured to project a planar light onto a surface of the object and form a illuminated plane. The image acquisition assembly includes an imaging sensor and a lens. The imaging sensor is configured to capture an image of an imaging plane, wherein the imaging plane is substantially parallel to the illuminated plane and is located in the illuminated plane. The lens has a major axis and is disposed between the illuminated plane and the imaging sensor. The lens is positioned relative to the imaging sensor such that the major axis is offset from a sensor axis, wherein the sensor axis is substantially perpendicular to the imaging sensor and passes through the imaging sensor One center. The data unit (typically a computer having one display, or a single display) is configured to receive the captured image and use at least the captured image to form a contour, shape, or other planar feature.

The above and other aspects, features, details, utilities and advantages of the present invention will be apparent from the description and appended claims.

10‧‧‧3D objects

12‧‧‧External surface

14‧‧‧Contour detection system

14a‧‧‧Contour detection system

16‧‧‧Complex profile

18‧‧‧Lighting assembly

20‧‧‧Light source

20a‧‧‧Light plane source

22‧‧‧Light plane

24‧‧‧ images

24 ₁ ‧‧‧First image

24 ₂ ‧‧‧Second image

24 ₃ ‧‧‧ Third image

26‧‧‧ Outline section

26 ₁ ‧‧‧First contour section

26 ₂ ‧‧‧Second contour section

26 ₃ ‧‧‧The third contour section

28‧‧‧Image acquisition assembly

28 ₁ ‧‧‧Image acquisition assembly

28 ₂ ‧‧‧Image acquisition assembly

28 ₃ ‧‧‧Image acquisition assembly

30‧‧‧ lens

32‧‧‧Main axis

34‧‧‧Sensor axis

36‧‧‧First predetermined distance

38‧‧‧second predetermined distance

40‧‧‧ imaging sensor

41‧‧‧ dotted line

42‧‧‧Focused imaging plane

42 ₁ ‧‧‧Focused imaging plane

42 ₂ ‧‧‧Focused imaging plane

42 ₃ ‧‧‧Focused imaging plane

44‧‧‧Predetermined size/range

46‧‧‧ third predetermined distance

48‧‧‧data unit

50‧‧‧Electronic processor

52‧‧‧ memory

54‧‧‧ contour generator

56‧‧‧Circular body/ring body

58‧‧‧Laser

60 ₁ ‧ ‧ first common point

60 ₂ ‧‧‧second common point

60 ₃ ‧‧‧ Third common point

310‧‧‧Antenna material layer / printed object

312‧‧‧Substrate

314‧‧‧XY

328‧‧‧Image acquisition assembly

330‧‧‧ lens

340‧‧‧ imaging sensor

341‧‧‧left field of view distance

343‧‧‧ Right field of view distance

351‧‧‧ pump

352‧‧‧ Container

353‧‧‧ device

354‧‧‧Air/ink mixture

355‧‧‧ needle

356‧‧‧ aerosol spray

388‧‧‧Second image acquisition assembly

A‧‧‧ longitudinal axis

Figure 1A is a diagrammatic and schematic view of a specific example of a system for determining the contour of an object.

FIG. 1B is a diagrammatic view of an image captured using the system of FIG. 1A, showing a section corresponding to a portion of the contour of the object.

Figure 1C is an enlargement of the portion of Figure 1A.

2 is an embodiment of a data unit.

Figure 3 is a diagrammatic and schematic view of an alternate configuration for determining the contour of an object.

4 is a diagram and schematic view of a conventional laser triangulation profile measurement system.

5 through 7 are front, rear, and side plan views, respectively, of another embodiment of a system for determining the contour of an object using a plurality of offsets suitable for determining the contour of the circumference of the three-dimensional object. Image acquisition assembly.

8A-8C are simplified pictorial views showing a plurality of discrete contour segments on respective images captured using the specific examples of FIGS. 5-7, and such contour segments correspond to respective portions of the contour of the object.

Figure 8D is a simplified pictorial view showing a combination of the plurality of segments of Figures 8A-8C.

Figure 9 is a flow chart showing a method of forming an outline of an object.

Figure 10 illustrates the currently designed microprinter.

Figure 11 illustrates a microprinter using a lens shift design.

Before proceeding with the detailed description of specific examples, a general overview of systems and methods for contour measurement will first be described. As described in [Prior Art], it is known to use a measurement angle of less than 90 degrees in a profile measurement system. However, as explained herein, the measurement resolution can be maximized when the measurement angle is 90 degrees, and in addition, the mathematical model for determining the contour and size of the object becomes simplified when the measurement angle is 90 degrees. However, known systems for profile measurement (especially systems with scanning capabilities) do not use a 90 degree measurement angle. The reason is at least double.

First, it is more desirable to have the light projection or imaging sensor perpendicular to the surface of the object being measured. This situation will reduce the math of the scan. Second, large measurement angles can cause hardware to interfere with objects being scanned unless a good portion of the field of view is wasted. As a result, a typical profile measuring device based on triangulation is designed to have a measurement angle of about 30 to 60 degrees. Some profile measuring devices may even have angles outside of this range. As a result, the optical resolution in the measurement plane (i.e., the location of travel of the light through the projected light pattern) will be part dependent, as viewed by the imaging sensor. That is, if the surface of the object intercepts the projected light pattern at different portions of the measurement plane, the measurement results in the pixel space will be different. In addition, a depth of focus is required because the measurement plane is offset from the imaging plane. High optical resolution (typically with a shallow depth of focus) can limit the measurement range or cause additional measurement variations. For stable objects, this situation may not be critical. However, true three-dimensional (3D) calibration can be a problem for some applications where the object to be measured can move substantially in the measurement plane.

A specific example in accordance with the teachings of the present invention uses a measurement angle of substantially 90 degrees such that the pixel resolution in the measurement plane will be substantially uniform. Additionally, a larger portion of the active imaging area on the imaging sensor will be available for imaging in the measurement plane, thereby increasing resolution (ie, for capturing pixels on the object, eg, all or at least of the pixels) most). A feature according to a specific example of the present teachings is a system for contour measurement (using triangulation) that uses a measurement angle of substantially 90 degrees (or substantially a measurement angle of 90 degrees) and fully utilizes imaging sensing The active imaging area of the device.

Specific examples of systems for determining the contour of an article (e.g., can be a three-dimensional object) can be used for several useful purposes, for example, in a manufacturing process to confirm or verify that the article is manufactured to a predetermined shape and/or predetermined size. specification. By way of example only, this profiling system can be used to determine the "roundness" of a circular object or to determine the "shape" of a non-circular object (eg, an H-beam or track). Specific examples of contour detection systems in accordance with the present teachings can be used to determine the actual shape of a steel article.

1A and 1C are diagrammatic and schematic views of a specific example of a contour detection system 14 for determining a contour 16 of a three-dimensional object 10 having an exterior surface 12 in accordance with the present teachings. The article 10 can extend along a longitudinal axis designated "A". In the illustrated embodiment, system 14 includes illumination assembly 18, image acquisition assembly 28, and data unit 48.

The illumination assembly 18 includes at least one line source 20 configured to project the light plane 22 onto the surface 12 of the object 10, such as a lightning ray or other source of light having the same effect. Line source 20 can have any wavelength or combination of wavelengths suitable for the selected imaging sensor and lens, either in the infrared, visible or ultraviolet region or known to be in the range of 0.01 microns to 1000 microns. The present invention will use the term "laser" as the line source 20 without loss of generality. Light plane 22 is also referred to as the measurement plane described above. In the illustrated embodiment, source 20 is configured relative to object 10 such that light plane 22 is substantially perpendicular to outer surface 12 of article 10, and thus perpendicular to longitudinal axis "A." In this case, the light plane and the measurement plane (i.e., the plane in which the light plane illuminates onto the surface of the object) will be the same. The light plane 22 interacts with the surface 12 of the object 10, wherein the object 10 can be imaged by the image capture assembly 28, as will be described below. It should be understood that if the cross-sectional geometry of the object 10 requires illumination from multiple illumination angles to extract a segment or contour of the object 10, the light plane 22 can be formed by more than one line source 20, and The light emitted by the line source 20 is substantially located in the light plane 22.

The image acquisition assembly 28 includes a lens 30 (eg, a converging lens or lens having similar functions) and an imaging sensor 40, both of which may comprise conventional constructions. By way of example only, imaging sensor 40 may comprise, by way of example only, a charge-coupled device (CCD), a complementary metal-oxide semiconductor (CMOS) device, or a video camera. Video camera tube. Image acquisition assembly 28 is configured to capture image 24 of the focused imaging plane 42 (best shown in FIG. 1B) that will contain contour regions corresponding to portions of contour 16 imaged by image acquisition assembly 28. Paragraph 26. In the illustrated embodiment, the image acquisition assembly 28 (particularly the lens 30) The imaging sensor 40) is configured relative to the source 20 such that the focused imaging plane 42 is substantially located in the measurement plane in which the light plane 22 interacts with the exterior surface 12 of the object 10. In other words, the focused imaging plane 42 is substantially parallel to the light plane 22 (i.e., the measurement plane in the particular example illustrated) and is located in the light plane 22.

Additionally, lens 30 is off center with respect to imaging sensor 40 as if imaging sensor 40 is larger (illustrated as dotted line 41 in Figure 1A, and is preferred in Figure 1C for purposes of detail). Zoomed in and centered on the lens 30. Lens 30 has a major axis 32 associated therewith. In addition, imaging sensor 40 also has a sensor axis 34 associated therewith that is substantially perpendicular to the plane of imaging sensor 40 and passes through the center of imaging sensor 40. The offset is achieved by locating the lens 30 between the light plane 22 and the imaging sensor 40 such that the main axis 32 is offset from the sensor axis 34 by a first predetermined distance 36. Image acquisition assembly 28 (i.e., lens/sensor) is radially offset from longitudinal axis "A" by a second predetermined distance 38. Because of these relationships, imaging plane 42 is characterized by a predetermined size/range 44, as shown by the volume enclosed by the expanded dashed line in Figure 1A. The size of the imaging plane 42 can be described in two dimensions, for example, as a third predetermined distance 46 on the vertical or Y axis and as a further predetermined distance on the horizontal or X axis (not shown in Figure 1A, but Will be treated as an extension into/out page). In practice, the person can position the lens 30 to center to the dotted line 41 (assuming a larger imaging sensor) to achieve a larger field of view where the intended imaging plane 42 is located, and then place the actual imaging sensor 40 at the dotted line. The position within 41 is such that the actual field of view is mapped to the desired imaging plane 42. Those skilled in the art will be aware of the fact that the size and position of the imaging plane 42 is determined by the size and position of the imaging sensor 40, the optical properties of the lens 30, the predetermined distance, and known optical rules such as line of sight.

The data unit 48 is configured to receive and process the image 24 from the image acquisition assembly 28 and form a contour 16. In one embodiment, the data unit 48 is a video signal organization device that can distribute images from the image acquisition assembly 28 to a corresponding display (not shown in FIG. 1) suitable for the user to view the contour 16, such as a video multiplexer. . The contour section 26 corresponds to a portion of the contour 16 And indicating that the light plane 22 is incident on the outer surface 12 of the article 10. Thus, the plurality of image acquisition assemblies 28 that produce the plurality of contour segments 26 can be disposed on a plurality of displays (not shown in FIG. 1) such that the contour segments 26 form a full outline 16 of the object 10 on the displays.

However, those skilled in the art will appreciate advances in the field of electronic processing, and it should be understood that, as illustrated in FIG. 2, an alternate embodiment is such that data unit 48 includes one or more electronic processors 50 (which may be of conventional construction) And an associated memory 52 (which may also be of a conventional construction). The data unit 48 may further include a contour generator 54 which, in one embodiment, may include software stored in the memory 52, the software being configured with a prescribed program and a transformation model when executed by the processor 50 The image 24 is processed and the contour section 26 contained in the image 24 is determined (best shown in FIG. 1B). In this particular example, the plurality of image acquisition assemblies 28 that generate the plurality of contour segments 26 can be configured such that the contour segments 26 form the full contour 16 of the article 10 in the data unit 48, after which the article 10 is formed on the display. Full outline 16. In yet another alternative embodiment, the contour generator 54 may include, in whole or in part, a computing hardware that replaces or supports the software for performing the functions described herein.

Referring now to Figures 1A-1C, it is advantageous in accordance with the specific embodiments of the present teachings that the imaging plane 42 is parallel to the light plane 22. This relationship will result in a linear measurement model and uniform pixel resolution in the measurement plane. There may be an optimized focus for the best measurement on the measurement plane, since the measurement plane does not deviate from the imaging plane 42. That is, the desired depth of focus in the present teaching is substantially close to zero. This situation is particularly suitable for applications involving high optical resolution. This configuration will also simplify three-dimensional (3D) calibration when combining multiple contour segments to form a complete contour, as described in more detail below. The offset of the lens 30 relative to the imaging sensor 40 (and the object 10) causes the imaging plane 42 to be properly positioned relative to the imaging sensor 40 such that the full range 44 (i.e., the size of the imaging plane 42) is fully available The contour of the object 10 is measured while providing a clear path of movement along the axis "A" for the object 10 without otherwise interfering with other items such as the image capture assembly 28.

FIG. 3 shows an alternative configuration that does not fully achieve the advantages of the specific example of FIG. 1A. Where the lens 30 is positioned in a typical centered position (ie, the main lens axis coincides with the sensor axis), as illustrated in Figure 3, the imaging plane 42 will have a larger range, which is shown as compared to the figure A specific example of 1A has a large vertical extent. However, this alternative configuration achieves less desirable optical resolution because approximately 50% or more of the imaging plane 42 along the Y axis alone as shown in FIG. 3 will be due to the imaging sensor 40 (and Horizontal interference to lens 30) is also not available.

Figure 4 shows a conventional configuration of profile measurement settings as known in the art. The imaging plane 42 in Figure 4 is not parallel to the measurement plane. Although this configuration of the imaging plane 42 pixel resolution uniform, but as the imaging sensor 40 to measure the viewing plane through the projection on the pixel resolution will not be uniform.

In another specific example, a contour detection system (hereinafter system 14a) incorporates a modified illumination assembly 18 that is configured to project a light plane around the circumference of the object, and is configured to image around the circumference of the object. Multiple images acquire assembly 28. The system 14a thus configured is capable of completely performing contour detection around the entire circumference of the object.

5 through 7 are isometric views of a system 14a for determining a contour around the entire circumference of the three-dimensional object 10. System 14a includes a light plane source 20a that is similar to light source 20 in FIG. 1A, but that is specifically configured to project light plane 22 around the entire circumference of object 10. In one embodiment, the light plane source 20a includes an annular (i.e., ring) body 56 with a plurality of lasers 58 disposed about the annular body 56. Each laser 58 produces a respective Ray Ray. The lasers 58 are disposed on the ring body 56 and aligned (each laser is aligned with respect to other lasers) such that a plurality of lightning rays generated by the laser 58 are substantially located in the light plane 22.

System 14a further includes a plurality of image acquisition assemblies 28 similar to the image acquisition assembly shown in FIG. 1A. As an example, the illustrated example of system 14a includes three image acquisition assemblies 28 ₁ , 28 _{2 ,} and 28 ₃ circumferentially disposed relative to the longitudinal axis "A" without loss of generality. Each of the image acquisition assemblies 28 ₁ , 28 _{2 ,} and 28 _{3 is} radially offset from the axis "A" by a second predetermined distance 38 (as in assembly 28 of Figure 1A). In the illustrated embodiment, the three image acquisition assemblies 28 ₁ , 28 _{2 ,} and 28 ₃ are configured at intervals of approximately 120 degrees (evenly about the axis "A").

However, it should be understood that although three image acquisition assemblies 28 ₁ , 28 _{2 ,} and 28 ₃ are used in the illustrated embodiment for full contour detection of circular objects, more or more may be used in other embodiments. The image acquisition assembly is less dependent on at least (i) the shape of the object, and (ii) the desired contour to be output. For example, in some embodiments, six, seven, eight, or more image acquisition assemblies may be used, for example, for certain complex shapes, such as "H" beams or tracks. The use of multiple image acquisition assemblies will be optimized based on the cross-sectional geometry of the object 10. The position of the assembly 28 may or may not be evenly spaced around the circumference of the article 10. The second predetermined distance 38 for the assembly 28 can be individually selected for each of the assemblies 28 and need not be the same.

Image acquisition assembly _{281, 282} and ₂₈₃ of each of the respective image capturing plane _{421, 422} and the respective images of _{241 423, 242, 243} (FIGS. 8A to 8C best Shown). Although not shown in FIGS. 5-7, system 14a also includes a data unit 48 similar to the data unit in system 14 (FIG. 1A) to process images 24 ₁ , 24 ₂ , 24 _{3 together} to form contour 16. In some embodiments, the article 10 can be moved along the axis "A" rather than stationary.

One advantage of the offset image acquisition assembly is the ease with which multiple data segments (images 24 ₁ , 24 ₂ , 24 ₃ ) can be processed and integrated to form the composite contour 16 . In a conventional configuration, each image acquisition assembly will have its own 3D triangulation function. In these configurations, having three, four, or even eight imagers will greatly complicate the overall system calibration process.

In a specific example in accordance with the teachings of the present invention, contour data (contour segments) obtained from each image 24 ₁ , 24 ₂ , 24 ₃ can be more easily attributed to the availability of 2-dimensional (2D) uniform mapping. Tied together or mapped to form a composite contour. In these specific examples, the integration of multiple (eg, three) data sets from multiple image acquisition assemblies requires only two-dimensional planar calibration of the laser plane without the need for three-dimensional nonlinearities as in the prior art. calibration. The overlap of at least some portions of the focused imaging planes represented as 42 ₁ , 42 ₂ , 42 ₃ allows the data unit 48 to perform calibration on 2D based on at least overlapping portions of the contour segments from the image acquisition assembly.

8A to 8C are images obtained from the respective assembly _{281, 282} and ₂₈₃ the image obtained of _{241, 242, 243} to simplify the representation, wherein the images _{241, 242, 243} contained in each Or otherwise present a respective contour section 26 ₁ , 26 ₂ , 26 ₃ . Regarding system 14a, contour generator 54 (implemented in data unit 48) is configured to determine first contour segments 26 ₁ in first image 24 ₁ , second image 24 _{2 ,} and third image 24 ₃ , respectively The second contour section 26 ₂ and the third contour section 26 ₃ . The contour sections 26 ₁ , 26 ₂ , 26 ₃ respectively correspond to the first portion, the second portion and the third portion of the composite profile 16 of the article 10. Each of the first contour section 26 ₁ , the second contour section 26 _{2 ,} and the third contour section 26 ₃ may include a respective two-dimensional contour section, as shown.

FIG. 8D is a diagrammatic view of composite profile 16. The contour 16 can be formed by a contour generator 54 (implemented on data unit 48). To determine the composite profile, the profile generator 54 can be further configured with a calibration process that identifies common points and geometric features between any two adjacent profile segments. As an example shown in FIG. 8D, profile generator 54 may identify (i) a first common point 60 ₁ between first contour segment 26 ₁ and second contour segment 26 ₂ without loss of generality. (ii) a second common point 60 ₂ between the second contour section 26 ₂ and the third contour section 26 ₃ , and (iii) between the first contour section 26 ₁ and the third contour section 26 ₃ The third common point is 60 ₃ . The contour generator 54 is still further configured to use at least the first contour segment 26 ₁ , the second by utilizing at least the identified first common point 60 ₁ , the second common point 60 _{2 ,} and the third common point 60 ₃ The contour section 26 ₂ and the third contour section 26 ₃ together with other dimensions and geometric features (such as diameter) of the article 10 form the contour 16 of the article 10. It should be understood that in a specific example, the first image 24 ₁ , the second image 24 _{2 ,} and the third image 24 _{3 may be} first recorded to a common coordinate system. It should also be appreciated that if the cross-section of the object 10 is a polygon, the contour section 26 can be part of a polygon such as a square or a hexagon, such that common points and other dimensions and geometric features are more easily identified during the calibration process ( Such as the angle and length of the edge). If an object 10 having known dimensions and geometric features is provided, the calibration process will result in a transformation model that coordinates the contour segment 26 produced by the image acquired by the free image acquisition assembly 28 at the composite contour 16 The system transforms into a contour section 26'. Each image acquisition assembly 28 will have its own unique transformation model such that contour segments 26 from different image acquisition assemblies 28 are transformed into the same coordinate system for merging into composite contours 16. The described calibration process can servo a system having N image acquisition assemblies 28, where N is an integer equal to or greater than two.

Figure 9 is a flow diagram illustrating the processing sequence performed by system 14 (or 14a) to determine the contour of a three-dimensional object. The process sequence begins in step 62.

Step 62 involves projecting a light plane onto the outer surface 12 of the article 10. Step 62 can be performed substantially as described in the specific examples set forth above, for example, by operating at least one source of light to produce a light plane 22 (e.g., as in system 14), or extending the pathway to create a surrounding object The entire circumference is illuminated to the light plane 22 on the object (e.g., as in system 14a). The process proceeds to step 64.

Step 64 involves capturing the image of the imaging plane using the offset image acquisition assembly. Step 64 can be performed substantially as described in the specific examples set forth above. The imaging plane 42 will be substantially parallel to the light plane/measurement plane, and the main axis of the lens will be offset from the sensor axis to achieve the beneficial effects described above. In some embodiments, a single image acquisition assembly can be used to capture an image, while in other embodiments, multiple image acquisition assemblies can be used to capture a plurality of images. The process sequence then proceeds to step 66.

Step 66 involves using the captured image from step 64 or the captured images to form an outline of the object that can be a three-dimensional object. Step 66 can be performed substantially as described in the specific examples set forth above. For example, in a particular example of system 14a, step 66 may be performed by contour generator 54 by (i) determining a contour segment in the captured image; (ii) A transformation model obtained from the self-calibration process is applied to the contour segments; and (iii) combining the contour segments.

The system 14a can be configured in a different embodiment in that each image acquisition assembly 28 is individually coupled to an illumination assembly 18 and forms a contour scanner. Within the contour scanner, the relationship between the illumination assembly 18 and the image acquisition assembly 28 is fixed. Multiple contour scanners can be used to form a system with the same functionality of system 14a. In order to avoid interference of the light plane, those skilled in the art will appreciate that each profile scanner can be equipped with a light plane having a unique wavelength and that a corresponding optical filter can be used to select the light of interest for a particular profile scanner. flat. Another way is to offset the different contour scanners along the axis "A".

The profile detection functionality of the present teachings can be used alone and/or in conjunction with additional optical imaging functionality, such as surface inspection, such as performed by a surface inspection device, such as 2002. US Application No. 10/331,050 (the '050 Application) (now U.S. Patent No. 6,950,546) filed on Dec. 27, and U.S. Application Serial No. 12/236,886 filed on September 24, 2008 (the '886 application) The detection device described in the present invention (now U.S. Patent No. 7,627,163). Both the '050 application and the '886 application are hereby fully incorporated herein by reference.

It should be understood that system 14 (and system 14a) (particularly the primary electronic control unit (i.e., data unit 48)), as described herein, can include conventional processing devices known in the art, such conventional processing devices Pre-programmed instructions stored in associated memory can be executed, all performed in accordance with the functionality described herein. The electronic control unit may further be of a type having a combination of ROM, RAM, non-volatile and volatile (modifiable) memory such that any software can be stored and any software can still store and process dynamically generated data. And / or signal. It should be further understood that the terms "top", "bottom", "upward", "downward" and the like are for convenience of description only and are not intended to be limiting in nature.

Although one or more specific examples have been shown and described, this technique is familiar to It should be understood that various changes and modifications may be made without departing from the spirit and scope of the teachings.

The teachings of the present invention are also advantageous in view of other applications such as on-line measurement and monitoring for micro-printing or 3D printing. An aerosol needle will be used to print the micro-antenna on the substrate as an example without loss of generality. Figure 10 illustrates an existing design of a micro-antenna printer. Substrate 312 is typically mounted on XY stage 314, which can be moved according to commands to carry substrate 312 to a desired location relative to other fixtures in the printer. A pump 351 that supplies pressurized air is typically included that has the ability to control the purity, content, pressure, volume, and flow rate of the pressurized air. Pressurized air may mix ink from vessel 352 via a Venturi effect at device 353, which is a mixture of deposit material and solvent. Device 353 can include a valve that allows control of the ratio of air/ink mixture 354. The air/ink mixture stream is moved into a needle 355 that is typically affixed to the printer and escapes from the end of the needle as an aerosol spray 356. The air acts as a carrier for the ink and the ink will stay at the designated location on the surface of the substrate and form the desired layer of antenna material 310. Air/ink flow control and XY stage motion will form an antenna pattern on substrate 312.

In order to verify the print quality in terms of whether the antenna pattern meets design specifications, image acquisition assembly 328 is typically used. While illumination can be well designed in applications to project uniform illumination onto the area of interest on the substrate 312, in the use of orientation (eg, dark or coaxial illumination) or non-directional (eg, cloudy) illumination. In the present case, the assembly 328 is positioned such that its major axis is at an angle to the main axis of the aerosol needle to avoid mechanical interference. Due to this angle, the distance between the substrate 312 and the image capture assembly 328 is dependent and can vary significantly. As illustrated in Figure 10, the left field of view distance 341 is substantially less than the right field of view distance 343. As a result, image quality is often inadequate for printers. The varying distance (341/343) causes different pixel resolutions in the image. In addition, the scale of printing is often in the range of submicron to a few microns, and the depth of focus is very shallow at this optical resolution. The shallow focus depth limits the use of images acquired from assembly 328. In the practice of practice, the accurate size measurement and detection of printed antenna patterns A second image acquisition assembly 388 is required for the purpose, with the main axis offset from the aerosol needle and perpendicular to the substrate 312. However, the second assembly 388 cannot provide any information during printing.

The present invention can be used to solve this problem. 11 illustrates a specific example for determining a printed article 310 when the main axis (which is perpendicular to the printed article 310 and through the center of the printed article 310) is occupied by another article such as aerosol needle 355. A system of planar features such as 2D projection size or shape. The system includes an image acquisition assembly 328. The system can further include an illumination assembly (not shown in FIG. 11) configured to project planar light onto the surface of the object 312 and form a illuminated plane. The light may have any wavelength or combination of wavelengths suitable for the selected imaging sensor and lens, either in the infrared, visible or ultraviolet region or known to be in the range of 0.01 microns to 1000 microns. Image acquisition assembly 328 includes imaging sensor 340 and lens 330. Imaging sensor 340 is configured to capture an image of the imaging plane, wherein the imaging plane is substantially parallel to the illuminated plane and is located in the illuminated plane. Lens 330 has a major axis and is disposed between the illuminated plane and imaging sensor 340. Lens 330 is positioned relative to imaging sensor 340 such that the major axis is offset from the sensor axis, with the sensor axis being substantially perpendicular to imaging sensor 340 and passing through the center of imaging sensor 340. A data unit (not shown in FIG. 11) can be included, and the data unit can be configured to receive the captured image and provide at least observation or processing of the captured image for at least monitoring, measuring, and/or defect detection.

Those skilled in the art should be aware that external lighting may not be necessary. Depending on the material and temperature of the object to be imaged, self-emissive radiation, infrared, visible or ultraviolet light may be captured by an image acquisition assembly that is suitably selected to receive the radiation. For example, CCD sensors can be used for short-wavelength infrared and visible light, and microbolometer sensors can be used for long-wavelength infrared.

I claim that:

10‧‧‧3D objects

12‧‧‧External surface

14‧‧‧Contour detection system

16‧‧‧Complex profile

18‧‧‧Lighting assembly

20‧‧‧Light source

22‧‧‧Light plane

24‧‧‧ images

28‧‧‧Image acquisition assembly

30‧‧‧ lens

32‧‧‧Main axis

34‧‧‧Sensor axis

36‧‧‧First predetermined distance

38‧‧‧second predetermined distance

40‧‧‧ imaging sensor

41‧‧‧ dotted line

42‧‧‧Focused imaging plane

44‧‧‧Predetermined size/range

46‧‧‧ third predetermined distance

48‧‧‧data unit

A‧‧‧ longitudinal axis

Claims (26)

A system for generating a three-dimensional contour of an object, comprising: an illumination assembly configured to project a light plane onto an outer surface of the object; an image capture assembly including an image a sensor and a lens having an image plane and configured to capture an image on an imaging plane, wherein the imaging plane is substantially parallel to and in the light plane, the lens having a main axis disposed between the optical plane and the imaging sensor, the lens being positioned relative to the imaging sensor such that the main axis is offset from a sensor axis, wherein the sensor axis A portion substantially perpendicular to the imaging sensor and passing through a central portion of the imaging sensor; and a data unit configured to receive the image and form the three-dimensional contour from the image. The system of claim 1, wherein the lens is positioned between the optical plane and the imaging sensor such that one of the imaging planes projected on the optical plane is in a direction perpendicular to one of the optical planes. The imaging sensor and the lens are not interfered. The system of claim 1, wherein the lens is positioned relative to the imaging sensor to form the imaging plane having a predetermined size on the light plane. The system of claim 1, wherein the lens comprises a converging lens. The system of claim 1, wherein the illumination assembly is further configured to project the light plane from at least one line source. The line source of claim 5, wherein the line source comprises a line source selected from the group consisting of a laser, a structured illumination source, and a line shape light projector. The system of claim 1, wherein the illumination assembly is further configured to completely project the light plane around the outer surface of the object, and wherein the image acquisition is always a first image acquisition assembly and The image is a first image, and the first image capturing assembly is radially offset from a longitudinal axis by a first predetermined distance along which the longitudinal axis is disposed. The object, the system further comprising: an Nth image acquisition assembly, wherein N is an integer equal to or greater than 2, the Nth image acquisition assembly configured to respectively capture an Nth imaging plane located in the optical plane An Nth image, and wherein the Nth image acquisition assembly is radially offset from the longitudinal axis by an Nth predetermined distance, and the N image acquisition assemblies are circumferentially disposed relative to the longitudinal axis such that The N imaging planes collectively span the circumference of the object. The system of claim 7, wherein the N image acquisition assemblies are circumferentially disposed along the 360° circumference in a substantially evenly spaced manner. The system of claim 7, wherein the data unit comprises at least one electronic processor, the data unit further comprising a contour generator stored in the memory for execution by the at least one electronic processor, the contour generator The sections are configured to determine respective segments in the images, use predetermined predetermined models obtained from calibration to transform the segments, and use the segments to form the contours. For example, in the system of claim 7, wherein the N images are recorded to a single standard system. The record, as in claim 10, is based on the N images taken from a calibration object of one of the polygonal cross-sectional profiles. The system of claim 1, wherein the illumination assembly comprises a plurality of lasers, each of the lasers generating a thunder ray, wherein the plurality of lasers are disposed on a ring and aligned such that the plurality of thunders The ray is located in the plane of the light. The system of claim 1, wherein the imaging sensor comprises a sensing selected from the group consisting of a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS) device, and a video tube. Device. The system of claim 1, wherein the illumination assembly is configured relative to the object such that the light plane is substantially perpendicular to the outer surface of the object. A method of forming an outline of an exterior surface of an object, comprising the steps of: projecting a light plane onto an exterior surface of the object; using an offset imaging acquisition assembly to capture substantially parallel to the light plane And an image of one of the imaging planes in the optical plane, the offset imaging acquisition assembly includes an imaging sensor and a lens, wherein the lens has a main axis and is disposed on the optical plane and the imaging sensor And wherein the lens is positioned relative to the imaging sensor such that the main axis is offset from a sensor axis that is substantially perpendicular to the imaging sensor and passes through the imaging a central portion of the sensor; and using at least one of the captured images to form the contour using a data unit. The method of claim 15, wherein the projecting further comprises the step of completely projecting the light plane around the outer surface of the object. The method of claim 15, further comprising a plurality of offset image acquisition assemblies each capturing a respective image of one of the respective imaging planes in the optical plane, the method further comprising the step of: determining the complex number Each of the captured images is transformed using the predetermined individual models obtained from the calibration, and the segments are used to form the contour. The method of claim 15, wherein the offset image acquisition is always a first image acquisition assembly and the image is a first image, the method further comprising the steps of: acquiring the total using the Nth offset image respectively. Forming an Nth image of the Nth imaging plane located in the optical plane, where N is an integer equal to or greater than 2; determining N segments in the N images, wherein the Nth segments Corresponding to the Nth portion of the contour of the object, respectively, and wherein each of the N segments comprises a respective two-dimensional segment; transforming the N segments using a corresponding predetermined model obtained according to the calibration Each of them; and The N segments are used to form the contour of the object. The method of claim 18, wherein the N images are recorded to a single standard system. The record as set forth in claim 19 is based on the N images taken from a calibration object of one of the polygonal cross-sectional profiles. A system for producing a planar image of an object, comprising: an illumination assembly configured to project light onto a surface of the object and form a lighted plane on the surface of the object; An image acquisition assembly comprising an imaging sensor and a lens, the imaging sensor having an imaging plane and configured to capture an image on the imaging plane, wherein the imaging plane is substantially parallel to the illumination Plane and located in the illuminated plane, the lens has a main axis and is disposed between the illuminated plane and the imaging sensor, the lens is positioned relative to the imaging sensor such that the main axis The sensor axis is offset, wherein the sensor axis is substantially perpendicular to the imaging sensor and passes through a central portion of the imaging sensor. The system of claim 21, further comprising a data unit configured to receive the planar image for display purposes, for storage purposes, for processing purposes, for analysis purposes, or for the foregoing Any combination of purposes. The system of claim 21, wherein the lens is positioned between the illuminated plane and the imaging sensor such that one of the imaging planes projected onto the illuminated plane has a central axis, the center The axis is perpendicular to the illuminated plane and is offset from the central axis of the imaging sensor by a predetermined distance. The system of claim 21, wherein the lens is positioned relative to the imaging sensor to form the imaging plane having a predetermined size on the illuminated plane. A method of forming an image of an off-axis surface, comprising the steps of: Projecting light onto a surface of the object and forming a lighted plane; and using an offset imaging acquisition assembly to capture an image of one of the imaging planes substantially parallel to the illuminated plane and located in the illuminated plane, The offset imaging acquisition assembly includes an imaging sensor and a lens, wherein the lens has a major axis and is disposed between the optical plane and the imaging sensor, and wherein the lens is sensed relative to the imaging The device is positioned such that the main axis is offset from a sensor axis that is substantially perpendicular to the imaging sensor and passes through a central portion of the imaging sensor. The method of claim 25, further comprising using a program of a data unit configured to receive the image for display purposes, for storage purposes, for processing purposes, for analysis purposes, or Any combination of the foregoing objects.