Method and apparatus for inspecting materials

Abstract

A method for inspecting a material includes moving the material and identifying a defect location. The method includes moving a camera along a second path of movement in a second direction of movement, and moving a field of view (FOV) of the camera relative to the material along the second path of movement to coincide with the defect location. The method includes passing the defect through the field of view (FOV) as the material moves, and capturing images of the defect with the camera as the material moves and the defect moves through the FOV. The images include a first image of a first major surface, a second image of a second major surface, and a third image of an intermediate portion of the material between the first and second major surfaces. The method includes reviewing the multiple images to characterize the defect.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 63 / 060,896, filed August 4, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] (Technical field) FIELD OF THE DISCLOSURE The present disclosure relates generally to methods for inspecting materials, and more particularly to methods for inspecting materials using an inspection device with a camera. [Background technology]

[0003] Glass ribbons are commonly used in display applications, such as liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light-emitting diode displays (OLEDs), plasma display panels (PDPs), touch sensors, photovoltaic cells, and the like. Such displays can be incorporated into, for example, mobile phones, tablets, laptops, watches, wearable and / or touch-enabled monitors or displays. Glass ribbons can be inspected with a camera that captures an image of the glass ribbon, which is then inspected for defects within the glass ribbon. Because inspection often requires stopping the movement of the glass ribbon, the inspection process can be time-consuming and costly. Furthermore, inspecting the volume or interior of a glass ribbon between its major surfaces can be difficult and inaccurate. Thus, there is a need for a material inspection method that can more effectively and quickly inspect materials, such as glass ribbons. Summary of the Invention

[0004] The following presents a simplified summary of the disclosure in order to provide a basic understanding of some embodiments that are described in the detailed description.

[0005] In some embodiments, the inspection device can include a first inspection device and a second inspection device. As the material continuously moves, the first inspection device can identify the defect location of a defect in the material. The second inspection device can re-inspect the defect location by capturing multiple images of the defect. For example, the second inspection device can include one or more cameras. In some embodiments, one camera can capture images of the first major surface, a second camera can capture images of the second major surface, and a third camera can capture images of an intermediate portion of the material between the first and second major surfaces. In some embodiments, the location of a defect located within the intermediate portion can be determined based on the captured images of the intermediate portion. Additionally, in some embodiments, the one or more cameras can be movable along an axis perpendicular to the direction of movement of the material and parallel to the first major surface, such as the Y-axis. By moving the one or more cameras along the Y-axis, the one or more cameras can capture multiple images of the defect at multiple positions along the Y-axis as the material continuously moves.

[0006] In some embodiments, a method for inspecting a material can include moving the material in a first direction of movement along a first path of movement. The method can include identifying a defect location in the material. The method can include moving a camera along a second path of movement in a second direction of movement substantially perpendicular to the first direction of movement, such that a field of view (FOV) of the camera moves relative to the material along the second direction of movement to coincide with a location of the defect, the second path of movement being parallel to a first major surface of the material. The method can include passing the defect through the field of view (FOV) as the material moves along the first path of movement. The method can include capturing multiple images of the defect with the camera as the material moves in the first direction of movement and the defect passes through the FOV. The multiple images can include a first image of the first major surface of the material at the location of the defect, a second image of the second major surface of the material at the location of the defect, and a third image of an intermediate portion of the material between the first and second major surfaces at the location of the defect. The method can include reviewing the multiple images to characterize the defect.

[0007] In some embodiments, moving the material includes moving the material continuously along the first path of movement while the multiple images are captured.

[0008] In some embodiments, capturing the multiple images can include capturing a fourth image of the material before the defect passes through the field of view (FOV) and a fifth image of the material after the defect leaves the field of view (FOV).

[0009] In some embodiments, capturing the multiple images may include exposing the defect location to light from an illumination source, the illumination source including one or more of a dark field illumination source, a coaxial illumination source, a gradient illumination source, a diffuse illumination source, a cloudy illumination source, a bright field illumination source, a structured light illumination source, or a laser illumination source.

[0010] In some embodiments, the step of locating the defect may occur before the step of moving the camera to capture multiple images.

[0011] In some embodiments, the material may include a glass ribbon.

[0012] In some embodiments, a method for inspecting a material can include moving the material in a first direction of travel along a first path of travel. The method can include identifying a defect location in the material. The method can include moving a camera in a second direction of travel along a second path of travel, the second direction of travel being substantially perpendicular to the first direction of travel, and moving a field of view (FOV) of the camera relative to the material along the second path of travel to coincide with the location of the defect. The second path of travel can be parallel to a first major surface of the material. A camera axis between the camera and the first major surface can form an angle with the first major surface that is in the range of about 3 degrees to about 85 degrees. The method can include passing the field of view (FOV) through the defect as the material moves along the first path of travel. The method can include capturing, with the camera, multiple images of an intermediate portion of the material between the first and second major surfaces of the material at the defect location. The method can include reviewing the multiple images to determine the depth of the defect from the first major surface.

[0013] In some embodiments, capturing the multiple images may include capturing a first image of the defect while the defect is within the intermediate portion, capturing a second image of the defect within the intermediate portion a first time period after capturing the first image, and capturing a third image of the defect within the intermediate portion a second time period after capturing the second image.

[0014] In some embodiments, reviewing the plurality of images may include comparing the sharpness of the first image, the second image, and the third image to determine depth.

[0015] In some embodiments, a first image can be captured before the defect enters the depth of field of the camera, a second image can be captured with the defect located within the depth of field, and a third image can be captured after the defect leaves the depth of field.

[0016] In some embodiments, a method for inspecting a material can include moving the material in a first direction of movement along a first path of movement. The method can include identifying a first defect location of a first defect and a second defect location of a second defect in the material. The method can include moving a first camera along the second path of movement in a second direction of movement substantially perpendicular to the first direction of movement, such that a first field of view (FOV) of the first camera moves relative to the material along the second path of movement to coincide with the first defect location, the second path of movement being parallel to a first major surface of the material. The method can also include moving a second camera along a third path of movement in a second direction of movement substantially parallel to the second path of movement, such that a second field of view (FOV) of the second camera moves relative to the material along the third path of movement to coincide with the second defect location. The method can include passing the first defect through the first field of view (FOV) as the material moves along the first path of movement. The method may include passing a second defect through a second field of view (FOV) as the material moves along the first path of movement. The method may include capturing a first image of a first portion of the material at the location of the first defect with a first camera. The method may include capturing a second image of a second portion of the material at the location of the second defect with a second camera. The method may include reviewing the first and second images to characterize the first and second defects. The characterizing may include determining one or more of locations of the first and second defects, types of the first and second defects, or sizes of the first and second defects.

[0017] In some embodiments, moving the material can include moving the material continuously along a first path of movement while the first and second images are captured.

[0018] In some embodiments, the velocity of the material along the first path of movement in the first direction of movement can be in the range of about 25 mm / s to about 500 mm / s, and the velocity of the first camera along the first path of movement in the first direction of movement is zero.

[0019] In some embodiments, the exposure time of one or more of the first camera or the second camera may be less than about 2 microseconds.

[0020] In some embodiments, the step of passing the first defect through the first field of view (FOV) can occur before the second defect passes through the second field of view (FOV), with the third movement path located downstream of the second movement path relative to the first movement direction.

[0021] In some embodiments, the method can include moving the third camera in a second direction of movement along the second path of movement such that a third field of view (FOV) of the third camera can move relative to the material along the second path of movement to coincide with a third defect location of a third defect in the material.

[0022] In some embodiments, the first image can include one or more of a first major surface of the material at the location of the first defect, a second major surface of the material at the location of the first defect, or an intermediate portion of the material between the first major surface and the second major surface at the location of the first defect.

[0023] In some embodiments, the method may include, after capturing the first image, moving the first camera in a second direction along a second path of movement such that the first field of view (FOV) coincides with a third defect location of a third defect in the material.

[0024] In some embodiments, the method can include passing a third defect through a first field of view (FOV) as the material moves along the travel path, and capturing with the first camera a third image of a third portion of the material at the location of the third defect.

[0025] In some embodiments, the method can include orienting a camera axis of the first camera at an angle in a range of about 3 degrees to about 85 degrees relative to the first major surface so that the first image of the first portion includes an intermediate portion of the material between the first and second major surfaces of the material. In some embodiments, reviewing the first and second images can include determining a depth of the first defect from the first major surface.

[0026] Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description that follows, and in part will be apparent to those skilled in the art from this specification, or may be learned by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings. It is to be understood that both the foregoing summary and the following detailed description present embodiments that are intended to provide an overview or framework for understanding the nature and state of the embodiments disclosed herein. The accompanying drawings are included to provide a further understanding and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the present disclosure and, together with the description, serve to explain its principles and operation.

[0027] These and other features, embodiments and advantages will be better understood from the following detailed description when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0028] [Figure 1] 1A and 1B are diagrams illustrating an exemplary embodiment of an inspection apparatus, in accordance with an embodiment of the present disclosure. [Figure 2] 2 is a top-down view of an inspection apparatus taken along line 2-2 of FIG. 1 according to an embodiment of the present disclosure. [Figure 3]3 is a top-down view of an inspection apparatus similar to FIG. 2 after a period of time has passed, according to an embodiment of the present disclosure. [Figure 4] 2-3, a top-down view of an inspection apparatus similar to FIGS. 2-3, a period of time after FIG. 3, in accordance with an embodiment of the present disclosure. [Figure 5] 2-4, a top-down view of an inspection apparatus similar to that of FIG. 4, a period of time after that of FIG. 4, in accordance with an embodiment of the present disclosure. [Figure 6] 3 illustrates an image of an intermediate portion of a material between a first major surface and a second major surface that includes a defect, as captured in FIG. 2 in accordance with an embodiment of the present disclosure. [Figure 7] 7 shows an image of an intermediate portion of material between the first and second major surfaces containing the defect captured in FIG. 3 after a period of time has passed since FIG. 6, in accordance with an embodiment of the present disclosure. [Figure 8] 7 shows an image of an intermediate portion of material between the first and second major surfaces containing a defect, captured in FIG. 4, a period of time after FIG. 7, in accordance with an embodiment of the present disclosure. [Figure 9] 8 shows an image of an intermediate portion of material between the first and second major surfaces containing the defect captured in FIG. 5 after a period of time has passed since FIG. 8, in accordance with an embodiment of the present disclosure. [Figure 10] FIG. 3 illustrates an image of a first major surface of the material containing the defect captured in FIG. 2 according to an embodiment of the present disclosure. [Figure 11] 3 illustrates an image of a second major surface of a material containing a defect according to an embodiment of the present disclosure captured in FIG. 2. [Figure 12] FIG. 2 is a side view of a second inspection apparatus according to an embodiment of the present disclosure. [Figure 13] 13 is a side view of a second inspection apparatus after a period of time has passed since FIG. 12, in accordance with an embodiment of the present disclosure. [Figure 14] FIG. 14 is a side view of a second inspection device after a period of time has passed after FIG. 13 in accordance with an embodiment of the present disclosure. [Figure 15]FIG. 10 is a side view of a second inspection device including multiple camera devices arranged along one axis according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029]

[0013] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments are shown. Wherever practicable, the same reference numerals will be used throughout the drawings to refer to the same or like parts. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0030] As used herein, the term "about" means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not, and need not be, exact, but can be approximated and / or increased or decreased as necessary to reflect tolerances, conversion factors, rounding, measurement errors, etc., as well as other factors known to those of ordinary skill in the art.

[0031] Ranges may be expressed herein as from "about" one value and / or to "about" another value. When such a range is expressed, another embodiment includes from the one value to the other value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the value forms another embodiment. It will further be understood that the endpoints of each range are significant both in relation to the other endpoint, and independently of the other endpoint.

[0032] Directional terms used herein (e.g., up, down, right, left, front, back, top, bottom) are made with reference to the depicted figures and are not intended to denote absolute directions.

[0033] Unless expressly stated otherwise, methods described herein should not be construed as requiring that their steps be performed in a particular order, nor should any apparatus require a particular direction. Thus, where a method claim does not actually recite an order according to its steps, or where any apparatus claim does not actually recite an order or direction for individual components, or where the claims or the specification do not otherwise expressly state that the steps are limited to a particular order, or where no particular order or direction for the apparatus components is recited, no order or direction should be inferred in any respect. This applies to any available unstated basis for interpretation, including logical issues regarding the placement of steps, operational flow, component order, or component orientation, general meaning derived from grammatical structure or punctuation, and the number or type of embodiments described in the specification.

[0034] As used herein, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Thus, for example, reference to "a" element includes aspects having two or more such elements unless the context clearly dictates otherwise.

[0035] The terms "exemplary," "example," or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" or "example" is not to be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided merely for purposes of clarity and understanding and are not meant to limit or restrict in any way the disclosed subject matter or relevant portions of this disclosure. It can be appreciated that numerous additional or alternative examples of varying scope have been presented but omitted for the sake of brevity.

[0036] As used herein, the terms "comprises" and "includes," and variations thereof, unless otherwise indicated, are intended to be synonymous and open-ended. A list of elements following the transitional phrase "comprises" or "includes" is a non-exclusive list; other elements may be present in addition to the elements specifically set forth in the list.

[0037] As used herein, the terms "substantial," "substantially," and variations thereof are intended to indicate that a described characteristic is equal to or approximately equal to a value or description. For example, a "substantially flat" surface is intended to indicate a surface that is flat or approximately flat. Furthermore, "substantially" is intended to indicate that two values ​​are equal or approximately equal. In some embodiments, "substantially" can indicate values ​​that are within about 10% of each other, e.g., within about 5% of each other, or within about 2% of each other.

[0038] Modifications may be made to the present disclosure without departing from the scope or spirit of the claimed subject matter. Unless otherwise specified, terms such as "first," "second," and the like are not intended to imply a temporal aspect, a spatial aspect, an order, a quantity, or the like. Rather, such terms are used merely as identifiers, names, or the like of features, elements, items, and the like. For example, a first end and a second end generally correspond to end A and end B, or two different ends or two identical ends or the same end. Similarly, the capture of the second image can occur before capturing the first image, after capturing the first image, and / or without capturing the first image.

[0039] The present disclosure relates to an inspection apparatus and method for inspecting a material 101. The method and apparatus for inspecting the material 101 are described using exemplary embodiments. In some embodiments, the material 101 can include a glass ribbon from a ribbon of glass-forming material. As used herein, a "glass ribbon" is considered to be one or more of a glass ribbon in a viscous state, a glass ribbon in an elastic state (e.g., at room temperature), and / or a glass ribbon in a viscoelastic state between a viscous state and an elastic state. In some embodiments, the glass ribbon can include a glass sheet that can be separated from another portion of the glass ribbon. In some embodiments, the material 101 may not be limited to including a glass ribbon. Rather, in some embodiments, the material 101 can include one or more of a plastic material, a cell culture gel, a computer chip, an opaque material, a transparent material, and the like. As shown schematically in FIG. 1 , in some embodiments, the material 101 can be inspected by one or more inspection apparatuses, such as an inspection system including a first inspection apparatus 103 and a second inspection apparatus 105. A method for inspecting a material 101 may include moving (e.g., conveying) the material 101 along a first path of travel 111 in a first direction of travel 113. The first inspection device 103 and the second inspection device 105 may be positioned adjacent to the first path of travel 111 such that the material 101 can be inspected by the first inspection device 103 and the second inspection device 105 as the material 101 moves along the first path of travel 111 in the first direction of travel 113. In some embodiments, the second inspection device 105 may be located downstream of the first inspection device 103 with respect to the first direction of travel 113 such that the material 101 can first pass through the first inspection device 103 and then pass through the second inspection device 105 as the material 101 moves along the first path of travel 111.

[0040] The first inspection device 103 can include one or more cameras capable of inspecting the material 101 as it passes through the first inspection device 103, such that the first inspection device 103 can include a line scan camera. In some embodiments, the first inspection device 103 can include one or more of an illumination source, a computer, a power supply, a controller, etc., in addition to the one or more cameras. By inspecting the material 101, the first inspection device 103 can capture one or more images of the material 101. The one or more images of the material 101 can be reviewed, for example, for visual inspection by a user, for computer-processed inspection, etc. Reviewing the material 101, in some embodiments, can identify one or more defects in the material 101. In some embodiments, the first inspection device 103 can identify defect locations 115, 117 of the one or more defects. In some embodiments, the method may include identifying defect locations of defects in the material 101, such as identifying a first defect location 115 of a first defect 121, a second defect location 117 of a second defect 123, etc., in the material 101. Following identification of the defect locations 115, 117 of the one or more defects 121, 123 by the first inspection device 103, the second inspection device 105 may capture images of the defect locations 115, 117 to enable review or characterization (e.g., quantification of size, location from an edge of the material 101, location within a thickness of the material 101, etc.) of the one or more defects 121, 123. As shown in FIG. 1 , in some embodiments, the material 101 may move along an X-axis, and the first movement direction 113 may be parallel to the X-axis. Thus, the material 101 may include a thickness (e.g., between a first major surface and a second major surface) that may be measured along a Z-axis that is orthogonal to the X-axis.

[0041] 2, a top-down view of material 101 and second inspection device 105 is shown along line 2-2 of FIG. 1. In some embodiments, material 101 can include first and second major surfaces 201 and 203 facing in opposite directions and defining a thickness of material 101 therebetween. In some embodiments, material 101 can have a thickness of about 2 millimeters (mm) or less, about 1 millimeter or less, about 0.5 millimeters or less, such as about 300 micrometers (μm) or less, about 200 micrometers or less, or about 100 micrometers or less, although other thicknesses can be provided in further embodiments. For example, in some embodiments, material 101 can have a thickness in the range of about 20 micrometers to about 200 micrometers, about 50 micrometers to about 750 micrometers, about 100 micrometers to about 700 micrometers, about 200 micrometers to about 600 micrometers, about 300 micrometers to about 500 micrometers, about 50 micrometers to about 500 micrometers, about 50 micrometers to about 700 micrometers, about 50 micrometers to about 600 micrometers, about 50 micrometers to about 500 micrometers, about 50 micrometers to about 400 micrometers, about 50 micrometers to about 300 micrometers, about 50 micrometers to about 200 micrometers, about 50 micrometers to about 100 micrometers, or about 25 micrometers to about 125 micrometers, including all ranges and subranges of thickness therebetween. Additionally, material 101 can comprise a variety of compositions. For example, if material 101 comprises a glass material, material 101 may include borosilicate glass, aluminoborosilicate glass, alkali-containing or alkali-free glass, alkali aluminosilicate glass, alkaline earth aluminosilicate glass, soda-lime glass, glass-ceramic, etc. In some embodiments, material 101 may be processed into a desired application, for example, a display application.For example, material 101 can be used in a wide range of display applications, including liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), touch sensors, photovoltaic, and other electronic displays.

[0042] In some embodiments, the material 101 may be moved continuously in the first direction of movement 113 along the first path of movement 111. In some embodiments, by being moved continuously, the material 101 may not stop moving during inspection by the second inspection device 105, and the velocity of the material 101 may remain above zero as the material 101 passes through the second inspection device 105. In some embodiments, the material 101 may maintain a velocity that is at least about 300 mm / s while moving in the first direction of movement 113 along the first path of movement 111 past the second inspection device 105. In some embodiments, the material 101 may maintain a constant velocity while moving past the second inspection device 105. In this manner, the second inspection device 105 may capture images of the material 101, e.g., images of defect locations 115, 117, while the material 101 is moving continuously. In some embodiments, the material 101 can move in the first movement direction 113 in the X direction, while the height of the material 101 can be in the Y direction and the thickness of the material 101 can be defined in the Z direction. The material 101 can be moved in several ways. For example, in some embodiments, the material 101 can be placed on a conveying device (e.g., one or more rollers, belts, air cushions, etc.) that can support the weight of the material 101 and move the material 101 in the first movement direction 113. In some embodiments, the material 101 can be held by a gripping device (e.g., one or more suction grips, etc.) that can hold the material 101 and move it in the first movement direction 113. In some embodiments, the structure that supports or holds the material 101 while the material 101 is being conveyed or moved in the first movement direction 113 can be such that the first major surface 201 and the second major surface 203 are not obstructed from being inspected (e.g., images are captured) by the second inspection device 105.

[0043] 2 illustrates at least a portion of second inspection device 105. In some embodiments, second inspection device 105 can include one or more camera devices, such as camera device 207. In some embodiments, camera device 207 can include one or more cameras, such as first camera 211, second camera 213, and / or third camera 215. Camera device 207 can be positioned on a side of material 101, such as first side 219 of material 101 facing first major surface 201. Additionally or alternatively, in some embodiments, camera device 207 can be positioned on second side 221 of material 101 facing second major surface 203. As shown and described with respect to FIGS. 12-15 , in some embodiments, second inspection device 105 may not be limited to one camera device (e.g., camera device 207) as shown in FIG. 2 ; rather, second inspection device 105 may include additional camera devices that may be located upstream or downstream of camera device 207 relative to first direction of travel 113. In some embodiments, material 101 may include one or more defects (e.g., similar to first defect 121 and / or second defect 123 shown in FIG. 1 ). The defects may include, for example, one or more of first defect 225, second defect 227, or third defect 229. Material 101 may include multiple types of defects 121, 123, 225, 227, 229, for example, scratches, inclusions, bubbles, surface discontinuities, or other types of defects having opaque or transparent properties. Opaque defects are not transparent or translucent and may block or attenuate the passage of light therethrough, while transparent defects allow light to pass through. In some embodiments, the defects 121, 123, 225, 227, 229 may be located at one or more of the first major surface 201 (e.g., a first defect 225 located at the first major surface 201), the second major surface 203 (e.g., a second defect 227 located at the second major surface 203), or within a volume or interior of the material 101 between the first major surface 201 and the second major surface 203 (e.g., a third defect 229 within a volume or interior of the material 101).

[0044] In some embodiments, the first camera 211 can comprise a digital camera having a first camera axis 231 that intersects with the material 101. In some embodiments, the first camera axis 231 can be perpendicular to the material 101 (e.g., at an angle of about 90 degrees) or form an angle with the material 101 that can be in a range of about 80 degrees to about 100 degrees. The first camera 211 can capture one or more images of the material 101, e.g., the first major surface 201 of the material 101. In some embodiments, the first camera 211 can comprise one or more imaging lenses 233 (e.g., optical lenses, optical elements, etc.). As disclosed herein, the imaging lenses (e.g., 233) can comprise optically clear, transmissive optical devices that focus or disperse a light beam by refraction. In some embodiments, the first camera 211 can comprise an image sensor 235 that can be positioned to receive images formed from the one or more imaging lenses 233. As disclosed herein, an image sensor (e.g., 235) can receive, detect, and / or communicate data or information that can be used to form an image by converting light intensity into a signal. Thus, the image sensor 235 can digitize an image formed by one or more imaging lenses 233 to generate a digital image. In some embodiments, the image sensor 235 can comprise a complementary metal-oxide semiconductor (CMOS) sensor, a charge-coupled device (CCD) array, or the like. In some embodiments, the first camera 211 can include a field of view (FOV) 237 that can define an inspection area of ​​the material 101. The FOV can include the range of observable areas that can be viewed by the camera at a given time. In some embodiments, the first camera 211 can include a depth of field (DOF) that can be in the range of about 5 microns to about 100 microns, where the DOF is measured from the first major surface 201. The DOF can include the distance between the nearest and farthest objects that are in acceptably sharp focus in the image.

[0045] In some embodiments, the first camera 211 may include one or more illumination sources, such as a first illumination source 239. The first illumination source 239 may include, for example, a light emitting diode. In some embodiments, the first illumination source 239 may emit a first light 241, which may include one or more of a first wavelength λ1 (e.g., green light including light in a wavelength range between 520 nm and 530 nm), a second wavelength λ2 (e.g., red light including light in a wavelength range between 615 nm and 631 nm), a third wavelength λ3 (e.g., white light including light in a wavelength range between about 400 nm and about 750 nm), a fourth wavelength λ4 (e.g., white light including light in a visible wavelength range between about 400 nm and about 750 nm), etc. In some embodiments, the first illumination source 239 can provide one or more of dark field illumination, coaxial illumination, gradient illumination, diffuse illumination, cloudy illumination, bright field illumination, structured light illumination, laser illumination, etc. of the material 101.

[0046] In some embodiments, the second camera 213 can be similar or identical in some respects to the first camera 211. For example, the second camera 213 can comprise a digital camera having a second camera axis 251 that intersects with the material 101. In some embodiments, the second camera axis 251 can be perpendicular to the material 101 (e.g., at an angle of about 90 degrees) or form an angle with the material 101 that can be in the range of about 80 degrees to about 100 degrees. The second camera 213 can capture one or more images of the material 101, e.g., the second major surface 203 of the material 101. In some embodiments, the second camera 213 can comprise one or more imaging lenses 253 (e.g., optical lenses, optical elements, etc.). In some embodiments, the second camera 213 can comprise an image sensor 255 that can be positioned to receive images formed from the one or more imaging lenses 253. In some embodiments, the image sensor 255 can comprise a CMOS sensor, a CCD array, etc. The image sensor 255 can digitize the image formed by the one or more imaging lenses 253 to generate a digital image. In some embodiments, the second camera 213 can include a field of view (FOV) 257 that can define an inspection area of ​​the material 101. In some embodiments, the second camera 213 can include a depth of field (DOF) that can be in a range from about 5 microns to about 100 microns, where the DOF is measured from the second major surface 203.

[0047] In some embodiments, second camera 213 may include one or more illumination sources, such as second illumination source 259. Second illumination source 259 may include, for example, a light emitting diode. In some embodiments, second illumination source 259 may emit second light 261, which may include one or more of a first wavelength λ1 (e.g., green light including light in a wavelength range between 520 nm and 530 nm), a second wavelength λ2 (e.g., red light including light in a wavelength range between 615 nm and 631 nm), a third wavelength λ3 (e.g., white light including light in a wavelength range between about 400 nm and about 750 nm), a fourth wavelength λ4 (e.g., white light including light in a visible wavelength range between about 400 nm and about 750 nm), etc. In some embodiments, the second illumination source 259 can provide one or more of dark field illumination, coaxial illumination, gradient illumination, diffuse illumination, cloudy illumination, bright field illumination, structured light illumination, laser illumination, etc. of the material 101.

[0048] In some embodiments, the third camera 215 may be similar or identical in some respects to the first camera 211 or the second camera 213. For example, the third camera 215 may comprise a digital camera having a third camera axis 269 that intersects the material 101. In some embodiments, the third camera axis 269 between the third camera 215 and the first major surface 201 may form an angle with respect to the first major surface 201 that may be in a range of about 20 degrees to about 70 degrees. The third camera 215 may capture one or more images of the material 101, for example, an intermediate portion 271 of the material 101 between the first major surface 201 and the second major surface 203. The intermediate portion 271 may include a volume or an interior of the material 101. In some embodiments, the third camera 215 may comprise one or more imaging lenses 273 (e.g., optical lenses, optical elements, etc.). In some embodiments, the third camera 215 can include an image sensor 275 that can be positioned to receive images formed from the one or more imaging lenses 273. In some embodiments, the image sensor 275 can include a CMOS sensor, a CCD array, or the like. The image sensor 275 can digitize the images formed by the one or more imaging lenses 273 to generate a digital image. In some embodiments, the third camera 215 can include a field of view (FOV) 277 that can define an inspection area of ​​the intermediate portion 271 of the material 101. In some embodiments, the third camera 215 can include a depth of field (DOF) 282 that can be in a range from about 5 microns to about 100 microns, where the DOF is measured within the intermediate portion 271. Thus, in some embodiments, the method may include orienting the third camera axis 269 of the third camera 215 at an angle relative to the first major surface 201 within a range of about 20 degrees to about 70 degrees so that the first image of the first portion of the material 101 may include an intermediate portion 271 between the first major surface 201 and the second major surface 203.

[0049] In some embodiments, the third camera 215 may include one or more illumination sources, such as a third illumination source 279. The third illumination source 279 may include, for example, a light emitting diode. In some embodiments, the third illumination source 279 may emit a third light 281, which may include one or more of a first wavelength λ1 (e.g., green light including light in a wavelength range between 520 nm and 530 nm), a second wavelength λ2 (e.g., red light including light in a wavelength range between 615 nm and 631 nm), a third wavelength λ3 (e.g., white light including light in a wavelength range between about 400 nm and about 750 nm), a fourth wavelength λ4 (e.g., white light including light in a visible wavelength range between about 400 nm and about 750 nm), etc. In some embodiments, the third light 281 can provide one or more of dark field illumination, coaxial illumination, gradient illumination, diffuse illumination, cloudy illumination, bright field illumination, structured light illumination, laser illumination, etc. of the material 101.

[0050] In some embodiments, the camera apparatus 207 can include additional hardware or software components that can assist in controlling image acquisition by the cameras 211, 213, and 215, powering the cameras 211, 213, and 215, movement of the cameras 211, 213, and 215, and the like. For example, the camera apparatus 207 can include a computing device 283 (e.g., a computer, a server, a database, etc.). The computing device 283 can include a controller 285 that can control one or more of the operation of the cameras 211, 213, and 215 or the movement of the cameras 211, 213, and 215. In some embodiments, the controller 285 can include a multivariable controller that can receive image data from the cameras 211, 213, and 215. The controller 285 can include image processing software for evaluating the captured images of the material 101 and detecting defects in the material 101 based on the captured images. In some embodiments, the controller 285 can include a programmable logic controller, which can include a processor, memory, and / or input / output devices. The controller 285 may comprise a computer-readable medium for storing instructions for implementing the inspection methods disclosed herein. In some embodiments, the computing device 283 may comprise a power supply 287 for powering the cameras 211, 213, 215 and / or any motors that may drive the cameras 211, 213, 215. In some embodiments, the computing device 283 may be coupled to the cameras 211, 213, 215 in some manner that may facilitate the transfer of data and / or power to and from the cameras 211, 213, 215. For example, the computing device 283 and the cameras 211, 213, 215 may be coupled via a wired communication line (e.g., an Ethernet cable, a fiber optic cable, etc.), a wireless communication scheme (e.g., Bluetooth, Wi-Fi, etc.), etc.

[0051] In some embodiments, the camera device 207 may include additional components that can facilitate capturing images of the material 101. For example, in some embodiments, the camera device 207 may include a diffuser and a mirror that can be positioned on an opposite side of the material 101 from the first camera 211, the second camera 213, and the third camera 215. For example, in some embodiments, the diffuser and mirror can be positioned on the second side 221 of the material 101 while the first camera 211, the second camera 213, and the third camera 215 are positioned on the first side 219. In some embodiments, the diffuser can scatter light 241, 261, 281 from the illumination sources 239, 259, 279 to form scattered light within the FOV of the cameras 211, 213, 215. In some embodiments, one or more of the first camera 211, the second camera 213, or the third camera 215 may include a beam splitter that can direct the light 241, 261, 281 toward the material 101.

[0052] In some embodiments, the first camera 211, the second camera 213, and the third camera 215 can capture images of different portions of the material 101 such that defects 121, 123, 225, 227, 229 at different locations within the material 101 can be clearly imaged and reviewed. For example, due to the first camera 211 including a DOF at the first major surface 201, an image of a defect located at the first major surface 201, e.g., first defect 225, can be captured. In some embodiments, due to the second camera 213 including a DOF at the second major surface 203, an image of a defect located at the second major surface 203, e.g., second defect 227, can be captured. In some embodiments, due to the third camera 215 including a DOF at an intermediate portion 271 of the material 101 between the first major surface 201 and the second major surface 203, an image of a defect located within the intermediate portion 271, e.g., third defect 229, can be captured.

[0053] In some embodiments, a method of inspecting material 101 may include identifying a defect location of a defect in material 101. For example, with general reference to FIG. 1 , a first inspection device 103 may initially identify a first defect location 115 of a first defect 121 in material 101. In some embodiments, first defect location 115 may include an approximate location where first defect 121 is located in material 101. With reference to FIG. 2 , following this identification, a second inspection device 105 may capture an image at first defect location 115 to facilitate review of first defect 121 (e.g., location of first defect 121 in the Z direction between or between first major surface 201 and second major surface 203, size of first defect 121, type of first defect 121, etc.). In some embodiments, the method may include capturing multiple images of a defect (e.g., first defect 121) with cameras 211, 213, 215 as material 101 moves in first movement direction 113 and the defect (e.g., first defect 121) moves through the FOV. In some embodiments, the multiple images may include a first image of first major surface 201 at first defect location 115, a second image of second major surface 203 at first defect location 115, and a third image of an intermediate portion 271 of material 101 between first major surface 201 and second major surface 203 at first defect location 115. For example, in the embodiment of FIG. 2 , first defect location 115 may include multiple defects, e.g., first defect 225, second defect 227, and third defect 229. In other embodiments, first defect location 115 may include more or fewer defects than the number of defects illustrated in FIG. 2 . Images of intermediate portion 271 are illustrated in FIGS. 6-9, an image of first major surface 201 is illustrated in FIG. 10, and an image of second major surface 203 is illustrated in FIG.

[0054] In some embodiments, capturing the multiple images can include exposing the defect location (e.g., first defect location 115) to light 241, 261, 281 from illumination sources 239, 259, 279. For example, illumination sources 239, 259, 279 can include one or more of a dark-field illumination source, a coaxial illumination source, a gradient illumination source, a diffuse illumination source, a cloudy sky illumination source, a bright-field illumination source, a structured light illumination source, or a laser illumination source. In some embodiments, the dark-field illumination source can enhance contrast by illuminating a portion of the material 101 with light that may not be collected by the image sensor and therefore may not form part of the image. In some embodiments, the coaxial illumination source can include a beam splitter or semi-transparent mirror that splits the light from the illumination source, which can be fixed to a side, so that the light can be projected substantially parallel to the optical axis of the camera. In some embodiments, the gradient illumination source can emit light toward the material 101, and the intensity of the illumination can be varied in a gradient. In some embodiments, the diffuse illumination source can include a diffuser that scatters or diffuses light from the illumination source to transmit light. In some embodiments, the overcast illumination source can provide self-contained, continuous, diffuse illumination by reflecting light from a dome toward the material 101. In some embodiments, the bright field illumination source can include transmitting white light through the material 101, where attenuation of the transmitted light in dense regions of the material 101 can create contrast in the material 101. In some embodiments, the structured light illumination source can include projecting a pattern of light onto the material 101, where depth and surface information of the material 101 can be determined based on the deformation of the light from the material 101. In some embodiments, the laser illumination source can include a laser that emits spatially coherent light toward the material 101. In some embodiments, by exposing the defect location to light 241, 261, 281, one or more of the first illumination source 239, the second illumination source 259, or the third illumination source 279 can transmit the respective first light 241, second light 261, and / or third light 281 toward the material 101.In some embodiments, one or more of first illumination source 239, second illumination source 259, or third illumination source 279 may include one or more of a dark-field illumination source, a coaxial illumination source, or a gradient illumination source. In some embodiments, one type of light from one type of illumination source may be transmitted toward material 101, and one of the cameras may capture an image based on the light. In some embodiments, multiple different types of illumination from multiple types of illumination sources may be transmitted toward material 101, and multiple different cameras may capture the light (e.g., each camera may capture one type of light). In this manner, the different types of light captured by the multiple cameras may provide more images of the defect and, therefore, more accurate information about the defect. In some embodiments, moving material 101 may include continuously moving material 101 along first movement path 111 while multiple images are captured. For example, as disclosed herein, by being continuously moved, the material 101 does not have to stop moving during image acquisition by the cameras 211, 213, 215, and the velocity of the material 101 can remain above zero as it passes through the second inspection device 105.

[0055] 2 and 10 , the plurality of images can include a first image 1001 of a first major surface 201 of the material 101 at a first defect location 115. For example, as the material 101 moves in the first direction of movement 113, the first camera 211 can capture one or more images of the first major surface 201, where the one or more images can include the first image 1001. A first defect 225 can pass through the FOV of the first camera 211 such that the first image 1001 can display the first defect 225. With reference to FIGS. 2 and 11 , the plurality of images can include a second image 1101 of a second major surface 203 of the material 101 at the first defect location 115. For example, as the material 101 moves in the first direction of movement 113, the second camera 213 can capture one or more images of the second major surface 203, where the one or more images can include the second image 1101. The second defect 227 may pass through the FOV of the second camera 213 such that the second image 1101 may show the second defect 227 .

[0056] 2-9 , the plurality of images can include a third image of an intermediate portion 271 of the material 101 between the first major surface 201 and the second major surface 203 at the first defect location 115. For example, in some embodiments, the method can include using the third camera 215 to capture a plurality of images (e.g., as shown in FIGS. 6-9 ) of the intermediate portion 271 of the material 101 between the first major surface 201 and the second major surface 203 of the material 101 at the first defect location 115. As used herein, a third image can refer to one or more of the images (e.g., 601, 701, 801, 901) of the intermediate portion 271 shown in FIGS. 6-9 , where the various images 601, 701, 801, 901 represent the third defect 229 at different time periods. The method can include passing the third defect 229 through an FOV as the material 101 moves along the first movement path 111. 2-5 illustrate the progression of material 101 as it moves in first movement direction 113 during a time period. Thus, in some embodiments, capturing the multiple images may include capturing a first image of a defect (e.g., third defect 229) in intermediate portion 271 a first time period after capturing the first image, a second image of the defect (e.g., third defect 229) in intermediate portion 271 a first time period after capturing the first image, and a third image of the defect (e.g., third defect 229) in intermediate portion 271 a second time period after capturing the second image.

[0057] FIG. 2 shows the material 101 at a first time (t) when the third defect 229 has not yet passed through the DOF of the third camera 215. FIG. 3 shows the material 101 at a second time (t+1), where "1" represents a first time interval after the first time (t) when the third defect 229 has not yet passed through the DOF of the third camera 215, but is closer to the DOF than in FIG. 2. FIG. 4 shows the material 101 at a third time (t+2), where "2" represents a second time interval after the first time (t) when the third defect 229 has passed through the DOF of the third camera 215. FIG. 5 shows the material 101 at a fourth time (t+3), where "3" represents a third time interval after the first time (t) when the third defect 229 has passed through the DOF of the third camera 215 and has exited. Thus, FIG. 3 shows the location of third defect 229 at a later time when third defect 229 is in the location shown in FIG. 2. FIG. 4 shows the location of third defect 229 at a later time when third defect 229 is in the location illustrated in FIG. 3. FIG. 5 shows the location of third defect 229 at a later time when third defect 229 is in the location illustrated in FIG. 4. FIG. 6 shows a first image 601 of third defect 229 in the location illustrated in FIG. 2. FIG. 7 shows a second image 701 of third defect 229 in the location illustrated in FIG. 3. FIG. 8 shows a third image 801 of third defect 229 in the location illustrated in FIG. 4. FIG. 9 shows a fourth image 901 of third defect 229 in the location illustrated in FIG. 5.

[0058] 2 and 6, the first image 601 may be captured before the third defect 229 enters the DOF of the third camera 215, such that the first image 601 illustrates the third defect 229 in an out-of-focus position. As illustrated in FIG. 6, the third defect 229 may be out of focus and therefore may lack clarity and sharpness. With reference to FIGS. 3 and 7, the second image 701 may be captured before the third defect 229 enters the DOF of the third camera 215, such that the second image 701 illustrates the third defect 229 in an out-of-focus position. As illustrated in FIG. 7, the third defect 229 in the second image 701 may still be out of focus and therefore may lack clarity and sharpness. However, due to the third defect 229 being closer to the DOF in FIG. 3 than in FIG. 2 , the third defect 229 in the second image 701 may be more in focus than the third defect 229 in the first image 601. With reference to FIGS. 4 and 8 , the third image 801 may be captured as the third defect 229 passes through the DOF of the third camera 215, and the third image 801 may show the third defect 229 in a position that is in focus (or more in focus than the other images). As shown in FIG. 8 , the third defect 229 in the third image 801 may be in focus and therefore may be sharp and clear. Therefore, the third defect 229 in the third image 801 may be more in focus (e.g., clearer) than either the first image 601 or the second image 701. 5 and 9 , the fourth image 901 may be captured after the third defect 229 moves out of the DOF of the third camera 215, such that the fourth image 901 may show the third defect 229 in an out-of-focus position. As illustrated in FIG. 9 , the third defect 229 in the fourth image 901 may be out of focus and therefore may lack clarity and sharpness. In some embodiments, the third defect 229 in the fourth image 901 may have similar clarity to the third defect 229 in the first image 601 or the third defect 229 in the second image 701.However, the third defect 229 in the fourth image 901 may be out of focus and may not be as sharp as the third defect 229 in the third image 801 (e.g., the third image 801 was captured when the third defect 229 was within the DOF of the third camera 215).

[0059] 2-9 , in some embodiments, capturing multiple images can occur before, during, and after the third defect 229 passes through the DOF of the third camera 215. For example, in some embodiments, capturing multiple images can include capturing one or more of an image of the material 101 before the defect (e.g., the third defect 229) passes through the field of view (FOV) (e.g., the first image 601 or the second image 701) or an image of the material 101 after the defect (e.g., the third defect 229) leaves the field of view (FOV) (e.g., the fourth image 901). Thus, in some embodiments, an image (e.g., the third image 801) can be captured with the defect (e.g., the third defect 229) located within the DOF, and another image (e.g., the fourth image 901) can be captured after the defect (e.g., the third defect 229) leaves the DOF.

[0060] In some embodiments, the method may include reviewing the multiple images to characterize the defect, e.g., third defect 229. In some embodiments, the characteristics of the defect may include one or more of the following: defect size, defect shape, defect type, defect location, etc. For example, in some embodiments, the method may include reviewing the multiple images to determine the depth of third defect 229 from first major surface 201. Reviewing the multiple images to determine the depth of third defect 229 from first major surface 201 may include comparing the sharpness of the multiple images, e.g., first image 601, second image 701, third image 801, fourth image 901, etc. For example, with reference to FIGS. 6-9, the sharpness of third defect 229 in the multiple images may be compared. Comparing FIGS. 6 and 7, third defect 229 in second image 701 is sharper than third defect 229 in first image 601. 7 and 8, the third defect 229 in the third image 801 is sharper than the third defect 229 in the second image 701. Comparing FIGS. 8 and 9, the third defect 229 in the fourth image 901 is less sharp than the third defect 229 in the third image 801. Thus, because multiple images 601, 701, 801, 901 are captured over a period of time (e.g., as illustrated in FIGS. 2-5) during which the third defect 229 is moving in the first movement direction 113, it can be determined that the third defect 229 is likely closer to the second major surface 203 than to the first major surface 201 because the third defect 229 is sharper in the image that occurs later (e.g., the third image 801). Conversely, if the third defect 229 were located closer to the first major surface 201, the third defect 229 may pass through the DOF 282 at an earlier period of time. In this manner, the captured image of the third defect 229 (e.g., closer to the first major surface 201) may be sharper and more focused in the first image 601 or the second image 701, and less sharp and out of focus in later images, e.g., the third image 801 and the fourth image 901.

[0061] Third camera 215 is not limited to capturing four images 601, 701, 801, 901 of third defect 229 at four separate locations. Rather, in some embodiments, third camera 215 may capture additional images (e.g., more than four images) that may increase accuracy in reviewing multiple images to determine the depth of the defect from first major surface 201. For example, in some embodiments, third camera 215 may capture seven images of third defect 229. If the image of third defect 229 is clearest and most focused in the center of the image (e.g., the third image or the fourth image), it may be known that third defect 229 may be located toward the center of the thickness of material 101, approximately equidistant from first major surface 201 and second major surface 203. If the image of the third defect 229 is clearest and most focused in a previous image (e.g., the first image or the second image), it can be known that the third defect 229 may be located closer toward the first major surface 201. If the image of the third defect 229 is clearest and most focused in a later image (e.g., the sixth image or the seventh image), it can be known that the third defect 229 may be located closer toward the second major surface 203. Thus, by comparing the sharpness and focus of the defect in the multiple images, the method can include determining the location of the defect within the thickness (e.g., in the Z direction) of the material 101. In some embodiments, the reviewing step can be performed by a human operator or user, while in other embodiments, the reviewing step can be performed by software or artificial intelligence.

[0062] In some embodiments, the first camera 211, the second camera 213, and the third camera 215 can capture images at an image capture rate ranging from approximately 8 frames per second (fps) to 1000 fps. In some embodiments, the first camera 211, the second camera 213, and the third camera 215 can capture images at an exposure rate of 10 exposure times per millisecond (ms) (which can correspond to 100 fps) with pulsed illumination approximately every 1 ms (which can correspond to 1000 fps). To further facilitate image acquisition and data transfer by the first camera 211, the second camera 213, and the third camera 215, the second inspection device 105 can use one or more of the following methods: binning (e.g., combining or averaging some pixels in an image), skipping (e.g., skipping the reading of certain pixels), windowing (e.g., selecting a segment of the entire pixel value range and displaying pixel values ​​within that segment), or subsampling (e.g., reducing the image size). In some embodiments, the second inspection device 105 may include a distance sensor (e.g., a laser) that can actively measure and track the distance between the cameras 211, 213, 215 and the material 101 as the material 101 moves continuously during the inspection process.

[0063] Referring to FIG. 12, an embodiment of second inspection apparatus 105 is shown. In some embodiments, second inspection apparatus 105 can include one or more camera apparatuses, such as, for example, camera apparatus 207, second camera apparatus 1201, third camera apparatus 1203, and fourth camera apparatus 1205. In some embodiments, one or more of second camera apparatus 1201, third camera apparatus 1203, or fourth camera apparatus 1205 can be substantially identical to camera apparatus 207. For example, if second camera apparatus 1201, third camera apparatus 1203, and fourth camera apparatus 1205 are substantially identical to camera apparatus 207, then second camera apparatus 1201, third camera apparatus 1203, and fourth camera apparatus 1205 each include the structure of camera apparatus 207 shown and described with respect to FIGS. 1-11. For example, second camera device 1201, third camera device 1203, and fourth camera device 1205 may include first camera 211, second camera 213, third camera 215, computing device 283, controller 285, power supply 287, etc. However, second camera device 1201, third camera device 1203, and fourth camera device 1205 are not limited to being substantially identical to camera device 207. For example, in some embodiments, one or more of second camera device 1201, third camera device 1203, or fourth camera device 1205 may include some but not all of camera device 207, e.g., by including some but not all of first camera 211, second camera 213, third camera 215, computing device 283, controller 285, power supply 287, etc. 1-11, for example, by including some but not all of the first camera 211, second camera 213, third camera 215, computing device 283, controller 285, power supply 287, etc. Thus, second inspection device 105 may include one or more camera devices 207, 1201, 1203, 1205, which may or may not be identical.Furthermore, in some embodiments, the second inspection device 105 is not limited to including the four camera devices shown, but can instead include one or more camera devices.

[0064] In some embodiments, the camera devices 207, 1201, 1203, 1205 may be positioned consecutively in the first direction of travel 113 along the first path of travel 111. For example, relative to the first direction of travel 113, the camera device 207 may be located upstream from the second camera device 1201, which may be located upstream from the third camera device 1203, which may be located upstream from the fourth camera device 1205. In some embodiments, the camera devices 207, 1201, 1203, 1205 may be spaced apart from one another, for example, with equidistant or unequal spacing between adjacent camera devices 207, 1201, 1203, 1205.

[0065] In some embodiments, camera devices 207, 1201, 1203, 1205 can be mounted to guide members 1211, 1213, 1215, 1217, respectively. For example, camera device 207 can be mounted to first guide member 1211, second camera device 1201 can be mounted to second guide member 1213, third camera device 1203 can be mounted to third guide member 1215, and fourth camera device 1205 can be mounted to fourth guide member 1217. Guide members 1211, 1213, 1215, 1217 can facilitate movement of camera devices 207, 1201, 1203, 1205 in a second direction of movement 1219 that is substantially perpendicular to first direction of movement 113. For example, in some embodiments, the guide members 1211, 1213, 1215, 1217 can include beams, rods, or other structures to which the camera devices 207, 1201, 1203, 1205 can be movably mounted. In some embodiments, the guide members 1211, 1213, 1215, 1217 can each extend linearly along an axis such that the camera devices 207, 1201, 1203, 1205 can move along separate axes. For example, the second inspection device 105 can include a drive device 1228, such as one or more of a drive motor 1229, a motor encoder 1230, or a motor controller 1231, that can facilitate controlling the movement and position of the camera devices 207, 1201, 1203, 1205 relative to the material 101. In some embodiments, a single driver (e.g., driver 1228) may be coupled to camera device 207 and first guide member 1211 to cause movement of camera device 207. In some embodiments, a substantially identical driver (e.g., to driver 1228) may be coupled to the other camera devices 1201, 1203, 1205 and other guide members 1213, 1215, 1217 to cause movement of the other camera devices 1201, 1203, 1205.

[0066] Referring to the drive device 1228, in some embodiments, the drive motor 1229, motor encoder 1230, and motor controller 1231 can be electrically connected to one another to facilitate the provision of data (e.g., control instructions, position data, etc.), power, etc. In some embodiments, the drive motor 1229 can include a precision drive motor that can move one or more of the camera devices 207 relative to the guide member 1211, or move the camera devices 207 and guide member 1211 together. In some embodiments, the drive motor 1229 can move the camera devices 207 in precise increments so that the exact position of the camera devices 207 relative to the material 101 can be controlled. In some embodiments, the motor encoder 1230 can help control the operation of the drive motor 1229 and can provide motor position measurements to the motor controller 1231 so that the exact position of the camera devices 207 can be known. In some embodiments, the motor controller 1231 can receive position commands from the motor encoder 1230 and provide control commands to the drive motor 1229 and the motor encoder 1230 .

[0067] In some embodiments, the camera devices 207, 1201, 1203, 1205 can move along separate paths of movement to match the location of defects in the material 101 as the material 101 moves in the first direction of movement 113 along the first path of movement 111. For example, the camera device 207 can move along a second path of movement 1221, which can be substantially perpendicular to the first path of movement 111 and parallel to the second path of movement 1221. In some embodiments, the second camera device 1201 can move along a third path of movement 1223, which can be substantially perpendicular to the first path of movement 111 and parallel to the second path of movement 1221. In some embodiments, the third camera device 1203 can move along a fourth path of movement 1225, which can be substantially perpendicular to the first path of movement 111 and parallel to the second path of movement 1221. In some embodiments, the fourth camera device 1205 can move along a fifth path of movement 1227, which can be substantially perpendicular to the first path of movement 111 and parallel to the second path of movement 1221. In some embodiments, the distance separating the second path of movement 1221, the third path of movement 1223, the fourth path of movement 1225, and the fifth path of movement 1227 can be reduced due to the camera devices 207, 1201, 1203, 1205 moving in the second direction of movement 1219 (e.g., parallel to the Y-axis) but not in the first direction of movement 113 (e.g., parallel to the X-axis). By not moving in the first direction of movement 113 (e.g., parallel to the X-axis), the velocity of the camera arrangements 207, 1201, 1203, 1205 (e.g., including the first camera, second camera, third camera, etc.) along the first path of movement 111 in the first direction of movement 113 can be zero. In some embodiments, the distance separating the second path of movement 1221 from the third path of movement 1223, the distance separating the third path of movement 1223 from the fourth path of movement 1225, and / or the distance separating the fourth path of movement 1225 from the fifth path of movement 1227 can be in a range from about 300 mm to about 700 mm, or about 500 mm.In some embodiments, one or more of the camera devices 207, 1201, 1203, 1205 can move at least partially in the first direction of movement 113 (e.g., parallel to the X-axis). For example, by moving one or more of the camera devices 207, 1201, 1203, 1205 in the first direction of movement 113 (e.g., parallel to the X-axis), for example, at a speed that can be slower than the speed at which the material 101 moves in the first direction of movement 113, the amount of time that one of the defects is within the FOV of the camera devices 207, 1201, 1203, 1205 can be increased. Thus, the number of images and / or image quality can be increased due to the increased amount of time that the defect is within the FOV of one of the camera devices 207, 1201, 1203, 1205.

[0068] In some embodiments, the method may include identifying one or more defect locations before moving a camera (e.g., camera arrangement 207, 1201, 1203, 1205) to capture multiple images. For example, as shown and described with respect to FIG. 1 , first inspection arrangement 103 may identify defect locations for any identified defects. As shown in FIG. 12 , material 101 may include one or more defects, such as, for example, first defect 1233 located at first defect location 1234, second defect 1235 located at second defect location 1236, third defect 1237 located at third defect location 1238, and fourth defect 1239 located at fourth defect location 1240. Defects 1233, 1235, 1237, 1239 may be located at different locations within material 101, e.g., different locations along the X-axis and Y-axis. To accommodate these different positions along the X and Y axes, the camera devices 207, 1201, 1203, 1205 can be moved (e.g., along movement paths 1221, 1223, 1225, 1227) to match the defect locations 1234, 1236, 1238, 1240 along the Y axis. For example, moving the material 101 can include continuously moving the material 101 along the first movement path 111 while images (e.g., a first image, a second image, etc.) are captured.

[0069] 12-13, in some embodiments, the method may include moving a camera (e.g., a camera device 207 including a first camera 211, a second camera 213, and / or a third camera 215) along a second movement path 1221 in a second movement direction 1219 that may be substantially perpendicular to the first movement direction 113, such that a field of view (FOV) (e.g., a first field of view (FOV) 1301) of the camera device 207 can move relative to the material 101 along the second movement path 1221 to coincide with a defect location (e.g., a first defect location 1234), and such that the second movement path 1221 can be parallel to the first major surface 201 of the material 101. For example, after the first inspection device 103 (e.g., as shown in FIG. 1 ) identifies defect locations 1234, 1236, 1238, 1240, the camera devices 207, 1201, 1203, 1205 can be moved to positions that allow them to intercept the defects 1233, 1235, 1237, 1239 as the material 101, and thus the defects 1233, 1235, 1237, 1239, are moved in the first movement direction 113. For example, in some embodiments, the first movement direction 113 can be an X direction, while the second movement direction 1219 can be a Y direction. The camera device 207 can be moved in the second movement direction 1219 along the second movement path 1221 to coincide with the position along the Y axis where the first defect location 1234 is located. For example, the camera device 207 can reach a desired position along the Y axis before the first defect location 1234 passes through the first FOV 1301. Thus, as shown in Figure 13, the method can include passing a defect (e.g., first defect 1233) through the first FOV 1301 as the material 101 moves along the first path of movement 111.

[0070] In some embodiments, while passing the first FOV 1301 over the first defect 1233, the method can include capturing a first image (e.g., one or more of 601, 701, 801, 901, 1001, or 1101) of a first portion of the material 101 at the first defect location 1234 using the camera arrangement 207 (e.g., one or more of the first camera 211, the second camera 213, or the third camera 215). For example, capturing the first image can include capturing one or more images of one or more portions of the material 101 shown in FIGS. For example, in some embodiments, the first image may include one or more of the first major surface 201 of the material 101 at the first defect location 1234, the second major surface 203 of the material 101 at the first defect location 1234, or an intermediate portion 271 (e.g., as shown in FIG. 2 ) of the material 101 between the first major surface 201 and the second major surface 203 at the first defect location 1234. For example, as described with respect to FIGS. 2-11 , the camera device 207 may capture a first image 1001 of the first major surface 201 with the first camera 211. In some embodiments, the camera device 207 may capture a second image 1101 of the second major surface 203 with the second camera 213. In some embodiments, the camera device 207 may capture multiple images (e.g., 601, 701, 801, 901) of the intermediate portion 271 with the third camera 215. Thus, the first FOV 1301 may include one or more of FOV 237, FOV 257, or FOV 277 depending on the image location.

[0071] In some embodiments, passing the first defect 1233 through the first FOV 1301 can occur before the second defect 1235 passes through the second FOV 1305 on a third path of movement 1223 located downstream of the second path of movement 1221 relative to the first direction of movement 113. For example, a distance separating the first defect 1233 from a leading edge 1303 of the material 101 (e.g., a front edge of the material 101 relative to the first direction of movement 113) can be less than a distance separating the second defect 1235 from the leading edge 1303. Thus, the first defect 1233 can be closer to the leading edge 1303 than the second defect 1235. In some embodiments, if the distance separating the first defect 1233 and the second defect 1235 in the X direction is small such that the camera apparatus 207 cannot capture images of both the first defect 1233 and the second defect 1235 (e.g., because the camera apparatus 207 cannot move from the first defect 1233 to the second defect 1235 in time), the second camera apparatus 1201 can capture an image of the second defect 1235. For example, the second camera apparatus 1201 can include a second FOV 1305 such that the second camera apparatus 1201 can move in the second movement direction 1219 along the third movement path 1223 to coincide with the position along the Y axis where the second defect location 1236 is located. The second camera apparatus 1201 can reach the desired position along the Y axis before the second defect location 1236 passes through the second FOV 1305. Thus, as shown in FIG. 13, the second camera device 1201 has been moved to a desired position along the Y axis.

[0072] 14 , in some embodiments, the second defect 1235 can pass through the second FOV 1305. Accordingly, in some embodiments, the method can include moving a second camera (e.g., the second camera apparatus 1201 including one or more of the first camera 211, the second camera 213, or the third camera 215) in the second direction of movement 1219 along the third path of movement 1223 such that the second FOV 1305 of the second camera apparatus 1201 moves relative to the material 101 along the third path of movement 1223 to coincide with the second defect location 1236. In some embodiments, the method can include moving the second FOV 1305 through the second FOV 1305 as the material 101 moves along the first path of movement 111. In some embodiments, the method can include capturing, with the second camera device 1201, a second image (e.g., one or more of 601, 701, 801, 901, 1001, or 1101) of a second portion of the material 101 at the second defect location 1236. For example, capturing the second image can include capturing one or more images of one or more portions of the material 101 shown in FIGS. 2-11 , such that the second image can include one or more of the first major surface 201 of the material 101 at the second defect location 1236, the second major surface 203 of the material 101 at the second defect location 1236, or an intermediate portion 271 (e.g., shown in FIG. 2 ) of the material 101 between the first major surface 201 and the second major surface 203 at the second defect location 1236.

[0073] In some embodiments, the method may include reviewing the first image and the second image (e.g., the first image of the first defect 1233 and the second image of the second defect 1235) to characterize the first defect 1233 and the second defect 1235. For example, the characterization may include the location of the first defect 1233 and the second defect 1235 (e.g., on the first major surface 201, the second major surface 203, a location within an intermediate portion 271 between the first major surface 201 and the second major surface 203), the defect type of the first defect 1233 and the second defect 1235, the size of the first defect 1233 and the second defect 1235, etc.

[0074] 13 , in some embodiments, after capturing a first image of the first defect 1233 with the camera device 207, the method may include moving the camera device 207 along a second movement path 1221 in a direction (e.g., the second movement direction 1219 or a direction opposite to the second movement direction 1219) such that the first FOV 1301 coincides with a third defect location 1238 of a third defect 1237 in the material 101. For example, after one of the camera devices (e.g., the camera device 207) captures an image of the defect (e.g., the first defect 1233), the camera device may move along its respective movement path to capture another defect. In some embodiments, the camera device 207 may move to a position to capture an image of the third defect 1237. For example, the method may include passing a third defect 1237 in the first FOV 1301 as the material 101 moves along the first path of movement 111, and capturing an image of a third portion of the material 101 at the third defect location 1238 with the camera device 207. The third portion may include, for example, one or more of the first major surface 201, the second major surface 203, or the intermediate portion 271. However, the camera device 207 is not limited to capturing an image of the third defect 1237 after capturing an image of the first defect 1233. Rather, as shown in FIG. 14 , in some embodiments, the second inspection device 105 may include additional camera devices (e.g., a third camera device 1203, a fourth camera device 1205) that can capture images of the third defect 1237 and the fourth defect 1239. For example, instead of camera device 207 moving to a position to capture an image of third defect 1237, third camera device 1203 can be moved to a position to capture an image of third defect 1237, and fourth camera device 1205 can be moved to a position to capture an image of fourth defect 1239. Thus, as shown in Figures 13-14, camera device 207 can be moved to a position to capture an image of fifth defect 1307.

[0075] 15 , in some embodiments, second inspection apparatus 105 is not limited to including one camera apparatus per guide member 1211, 1213, 1215, and 1217. Rather, in some embodiments, second inspection apparatus 105 may include multiple camera apparatuses attached to a single guide member. For example, in some embodiments, second inspection apparatus 105 may include camera apparatus 207 and third camera apparatus 1501 attached to (and movable with) first guide member 1211. Third camera apparatus 1501 may be similar to or identical to any of camera apparatus 207, 1201, 1203, and 1205. In some embodiments, camera apparatus 207 may be moved to capture images of one defect (e.g., first defect 1233), while another camera apparatus (e.g., third camera apparatus 1501) may be moved to capture images of a different defect (e.g., third defect 1237). Thus, in some embodiments, the method may include moving a third camera (e.g., the third camera device 1501) along the second path of movement 1221 in a direction of movement (e.g., the second direction of movement 1219 or a third direction of movement 1502 opposite the second direction of movement 1219) such that a third FOV 1503 of the third camera device 1501 can move relative to the material 101 along the second path of movement 1221 to coincide with a third defect location 1238 of a third defect 1237 in the material 101. In this manner, if two defects are at different positions along the Y axis but similar or identical positions along the X axis, images of the two defects may be captured by two separate camera devices attached to and / or movable relative to the first guide member 1211.

[0076] In some embodiments, the second inspection device 105 can function as a high-speed inspection device due to one or more of the speed of the material 101 or the speed at which images can be captured. For example, in some embodiments, the material 101 can move continuously (e.g., without stopping) during image capture. The material 101 can move in the first movement direction 113 along the first movement path 111 at a speed that can be, for example, in a range of about 25 millimeters per second (mm / s) to about 500 mm / s. In some embodiments, the exposure of the multiple cameras can be less than about 5 ms, less than about 100 microseconds, or less than about 10 microseconds. In some embodiments, the exposure of one of the cameras can determine when the camera stops collecting light, which can be limited by a digital shutter in the image sensor or by an illumination pulse. In some embodiments, one or more of the cameras (e.g., first camera 211, second camera 213, and third camera 215) may capture images at 150 fps, which may correspond to an exposure time of 6.6 ms. In some embodiments, the exposure time of one or more of the cameras (e.g., first camera 211, second camera 213, and third camera 215) when an image (e.g., first image, second image, etc.) is captured may be less than about 2 microseconds. In some embodiments, the exposure time may be controlled by a combination of the illumination source or camera sensor due to the illumination source being on (e.g., providing light to material 101) and the shutters of the cameras (e.g., first camera 211, second camera 213, and third camera 215) being open.

[0077] In some embodiments, second inspection device 105 may include multiple different types of cameras. For example, in some embodiments, one or more of camera devices 207, 1201, 1203, 1205 may comprise one or more of cameras 211, 213, 215. Additionally or alternatively, in some embodiments, one or more of camera devices 207, 1201, 1203, 1205 may comprise one or more specialized inspection cameras that may be suitable for inspecting and capturing images of particular types of defects. For example, due to the limited movement of camera devices 207, 1201, 1203, 1205 in first direction of movement 113 (e.g., parallel to the X-axis) resulting in reduced spacing between paths of movement 1221, 1223, 1225, 1227, some embodiments may provide specialized inspection cameras that can be used to inspect for specific defects. For example, initially, first inspection device 103 may capture images of material 101 to identify the location of defects (e.g., macroscan). In some embodiments, first inspection device 103 may identify specific findings that can be reviewed by a dedicated inspection camera based on characteristics of the specific defects (e.g., defect size, defect location, defect shape, etc.). In some embodiments, the dedicated inspection camera may be suitable for inspecting these specific defects. Thus, the dedicated inspection camera may move (e.g., along one or more of movement paths 1221, 1223, 1225, 1227) to capture images of the material 101 and defects as they move in first movement direction 113. In some embodiments, the dedicated inspection camera may include a wavefront sensor, a laser sensor, etc. Additionally, in some embodiments, a specific type of illumination source may be used based on the defect. For example, if the first inspection device 103 identifies one type of defect, the second inspection device 105 can direct a particular type of light from one of the illumination sources to the defect, where the particular type of light can facilitate improved image acquisition of the defect.

[0078] The second inspection device 105 can provide several advantages. For example, by including multiple cameras (e.g., first camera 211, second camera 213, and third camera 215), the second inspection device 105 can capture images of multiple different portions of the material 101, such as the first major surface 201, the second major surface 203, and an intermediate portion 271 between the first major surface 201 and the second major surface 203. In some embodiments, a series of images of the intermediate portion 271 can be captured. By comparing the series of images, a user can determine the location of a defect located in the intermediate portion 271. Furthermore, in some embodiments, the multiple cameras can be moved along an axis (e.g., the Y-axis) perpendicular to the direction of movement of the continuously moving material and parallel to the first major surface of the material. By moving the multiple cameras along the Y-axis, the multiple cameras can capture images of different defects that may be located at different positions along the Y-axis. In this manner, the multiple cameras can re-inspect defects that may be initially identified by the first inspection device.

[0079] Additionally, multiple cameras allow for continuous movement of material during the inspection and reinspection process, thus increasing the speed of the process. In some embodiments, to reinspect a particular defect, multiple cameras can capture a first set of images of the particular defect at one position along the X-axis, and then different cameras can capture a second set of images of the particular defect at a different position along the X-axis. In some embodiments, multiple sets of images of a particular defect can be captured by different cameras, which can be beneficial because multiple sets of images (e.g., by different cameras) can provide a better confidence assessment associated with the defect. The confidence assessment can include a more accurate location of the defect, a size estimate of the defect, a characterization of the type of defect, etc. In some embodiments, a first type of illumination can be used in capturing the first set of images of the defect, while a second, different type of illumination can be used in capturing the second set of images of the defect. Furthermore, because multiple cameras are positioned and movable along different axes, multiple cameras can achieve more accurate positioning in the Y-direction, but less accurate positioning in the X-direction. For example, the multiple cameras can begin capturing images of the defect before the defect enters the FOV of the multiple cameras and can continue capturing images of the defect as it passes through the FOV and even after the defect leaves the FOV. Additionally, the multiple cameras can move along the Y axis a distance that can exceed the width of material 101, such that the multiple cameras can capture images of material 101 along substantially the entire width of material 101 in the Y direction.

[0080] While various embodiments have been described in detail with reference to certain illustrative and specific examples thereof, it should be understood that the disclosure should not be considered so limited, as numerous variations and combinations of the disclosed features are possible without departing from the scope of the appended claims. [Explanation of symbols]

[0081] 101 Material 105 Second Inspection Device 111 First Movement Path 113 First direction of movement 201 First main surface 203 Second main surface

Claims

1. 1. A method of inspecting a material, comprising: moving the material along a first path of travel in a first direction of travel; identifying a first defect location of a first defect and a second defect location of a second defect in the material; moving a first camera along a second path of movement in a second direction of movement substantially perpendicular to the first direction of movement, such that a first field of view (FOV) of the first camera moves relative to the material along the second path of movement to coincide with the first defect location, the second path of movement being parallel to a first major surface of the material; moving a second camera along a third path of motion in a second direction of motion substantially parallel to the second path of motion such that a second field of view (FOV) of the second camera moves relative to the material along the third path of motion to coincide with the second defect location; passing the first defect through the first field of view (FOV) as the material moves along the first path of movement; passing the second defect through the second field of view (FOV) as the material moves along the first path of movement; capturing with a first camera a first image of a first portion of the material at the first defect location; capturing with a second camera a second image of a second portion of the material at the second defect location; reviewing the first image and the second image to characterize the first defect and the second defect, wherein the characterizing includes determining one or more of a location of the first defect and the second defect, a type of the first defect and the second defect, or a size of the first defect and the second defect; orienting a camera axis of the first camera at an angle in a range of about 3 degrees to about 85 degrees relative to the first major surface such that the first image of the first portion includes an intermediate portion of the material between the first and second major surfaces of the material; reviewing the first image and the second image includes determining a depth of the first defect from the first major surface by capturing multiple images of the first defect at different time periods and determining a focus state among the multiple images. A method characterized by:

2. The method of claim 1 , wherein moving the material comprises moving the material continuously along the first path of movement while the first image and the second image are captured.

3. a velocity of the material along a first path of movement in the first direction of movement is in a range of about 25 mm / s to about 500 mm / s, and a velocity of the first camera along the first path of movement in the first direction of movement is zero; The method of claim 2.

4. The method of any one of claims 1 to 3, wherein an exposure time of one or more of the first camera or the second camera is less than about 2 microseconds.

5. 5. The method of claim 1, wherein the step of passing the first defect through the first field of view (FOV) occurs before the second defect passes through the second field of view (FOV), with the third movement path being located downstream of the second movement path with respect to the first movement direction.

6. 6. The method of claim 1, further comprising: moving a third camera along the second path of movement in the second direction of movement such that a third field of view (FOV) of the third camera moves relative to the material along the second path of movement to coincide with a third defect location of a third defect in the material.

7. 7. The method of claim 1, wherein the first image includes one or more of the first major surface of the material at the location of the first defect, the second major surface of the material at the location of the first defect, or an intermediate portion of the material between the first major surface and the second major surface at the location of the first defect.

8. 8. The method of claim 1, further comprising, after capturing the first image, moving the first camera along the second path of movement in the second direction of movement such that the first field of view (FOV) coincides with a third defect location of a third defect in the material.

9. 10. The method of claim 8, further comprising passing the third defect through the first field of view (FOV) as the material moves along the travel path, and capturing a third image of a third portion of the material at the location of the third defect with the first camera.

Images