Quartz glass crucible vision detection system and method based on binocular vision

Abstract

The application discloses a quartz glass crucible visual detection system and method based on binocular vision, and belongs to the field of bubble visual detection of quartz glass crucible. The quartz glass crucible visual detection system comprises a first line laser, a second line laser and a binocular camera arranged on a connecting support. During visual detection, the first line laser, the second line laser and the binocular camera are all directed to the transparent layer of the to-be-detected crucible. The first line laser and the second line laser can form an outer surface first line light spot and an outer surface second line light spot on the outer surface position of the transparent layer of the to-be-detected crucible, and form an inner surface first line light spot and an inner surface second line light spot on the inner surface position of the transparent layer of the to-be-detected crucible, thereby defining a reference surface for the transparent layer of the to-be-detected crucible, and helping to calculate the bubble depth and the thickness of the transparent layer of the to-be-detected crucible.

Description

Technical Field

[0001] This invention relates to the visual inspection of bubbles in quartz glass crucibles, and more particularly to a visual inspection system and method for quartz glass crucibles based on binocular vision. Background Technology

[0002] Quartz glass crucibles, used as containers for loading silicon materials, are essential auxiliary components in the production of monocrystalline silicon rods and have extensive applications in the photovoltaic and semiconductor monocrystalline silicon industries. The cross-section of a quartz glass crucible typically has a double-layer structure: the inner layer is colorless, called the transparent layer, characterized by its transparency, low bubble content, and the bubbles being spherical and evenly distributed; the outer layer is white, called the opaque layer, characterized by its opacity and the presence of numerous bubbles.

[0003] Chinese invention patent application CN104730087A, "Apparatus for Observing Bubbles in the Transparent Layer of a Quartz Glass Crucible" (publication date: June 24, 2015), includes: a zoom lens positioned above the quartz glass crucible; the zoom lens visually inspects the transparent layer inside the quartz glass crucible, enabling accurate measurement of the number and size of bubbles in the transparent layer. The drawback is that it cannot measure the depth of the bubbles. Summary of the Invention

[0004] The purpose of this invention is to address the problem that existing visual inspection devices cannot measure the depth of bubbles in quartz glass crucibles, and to provide a visual inspection system and method for quartz glass crucibles based on binocular vision.

[0005] To achieve the above objectives, the present invention provides a technical solution: a quartz glass crucible visual inspection system based on binocular vision, comprising: a first line laser, a second line laser, and a binocular camera mounted on a connecting bracket. During visual inspection, the first line laser, the second line laser, and the binocular camera are all pointed at the transparent layer of the crucible to be inspected. The first line laser and the second line laser are configured such that: the first line laser forms a first line spot on the outer surface and a first line spot on the inner surface of the transparent layer of the crucible to be inspected, respectively; and the second line laser forms a second line spot on the outer surface and a second line spot on the inner surface of the transparent layer of the crucible to be inspected, respectively. The binocular camera is configured such that: the field of view of the binocular camera at least covers the transparent layer of the crucible to be inspected. The beneficial effects are at least as follows: the first and second line lasers function to form the first and second line laser spots on the outer surface of the transparent layer of the crucible under inspection, and the first and second line laser spots on the inner surface of the transparent layer. This allows the outer surface fitting surface of the transparent layer to be determined from the first and second line laser spots, and the inner surface fitting surface to be determined from the first and second line laser spots, thus defining a reference surface for the transparent layer and aiding in calculating the bubble depth and thickness of the transparent layer.

[0006] A preferred embodiment of the visual inspection system for quartz glass crucibles further includes: a camera light source mounted on a connecting bracket, the camera light source being used to illuminate the crucible to be inspected. The camera light source is a ring light source. The beneficial effect is at least that the purpose of illuminating the crucible to be inspected by the camera light source is to allow the binocular camera to obtain better imaging results.

[0007] As a preferred embodiment of the visual inspection system for quartz glass crucibles, the first and second line lasers are arranged in a V-shape, one in front of the other; the two camera units of the binocular camera are also arranged in a V-shape, one on the left and one on the right. The advantages are at least that the overall layout is reasonable.

[0008] As a preferred option for the visual inspection system of quartz glass crucibles, both the first line laser and the second line laser are selected as linear line lasers.

[0009] As a preferred embodiment of the visual inspection system for quartz glass crucibles, the connecting bracket is fixed to a displacement robotic arm. The beneficial effect is at least that the relative position between the visual inspection system and the crucible to be inspected can be adjusted via the displacement robotic arm.

[0010] Another technical solution provided by this invention: a visual inspection method for quartz glass crucibles based on binocular vision, which is implemented through the aforementioned visual inspection system for quartz glass crucibles. The visual inspection method for quartz glass crucibles includes:

[0011] Step S1: The first line laser forms a first line spot on the outer surface of the transparent layer of the crucible under inspection, and the second line laser forms a second line spot on the outer surface of the transparent layer of the crucible under inspection. The binocular camera samples the first line spot, the second line spot, and the bubble in the transparent layer of the crucible under inspection.

[0012] Step S2: Determine the fitting surface of the outer surface of the transparent layer with respect to the outer surface of the crucible to be inspected, based on the first line spot and the second line spot on the outer surface.

[0013] Step S3: Determine the depth of the bubble in the transparent layer of the crucible under inspection based on the positional relationship between the bubble and the fitting surface of the outer surface of the transparent layer.

[0014] Step S4: Determine the number and size of the bubbles in the transparent layer of the crucible to be inspected based on the bubbles in the transparent layer.

[0015] The beneficial effect is that, in addition to determining the number and size of bubbles in the transparent layer of the crucible to be inspected, the depth of the bubbles in the transparent layer of the crucible to be inspected can also be determined.

[0016] Another technical solution provided by the present invention is a visual inspection method for quartz glass crucibles, which is implemented through the aforementioned visual inspection system for quartz glass crucibles. The visual inspection method for quartz glass crucibles includes:

[0017] Step S1: The first line laser forms a first line spot on the outer surface and a first line spot on the inner surface of the transparent layer of the crucible under inspection, respectively. The second line laser forms a second line spot on the outer surface and a second line spot on the inner surface of the transparent layer of the crucible under inspection, respectively. The binocular camera samples the first line spot on the outer surface, the second line spot on the outer surface, the first line spot on the inner surface, and the second line spot on the inner surface.

[0018] Step S2: Based on the first line spot and the second line spot on the outer surface, determine the fitting surface of the outer surface of the transparent layer of the crucible to be inspected; based on the first line spot and the second line spot on the inner surface, determine the fitting surface of the inner surface of the transparent layer of the crucible to be inspected.

[0019] Step S3: Determine the thickness of the transparent layer of the crucible to be inspected based on the positional relationship between the fitting surface of the outer surface of the transparent layer and the fitting surface of the inner surface of the transparent layer.

[0020] The beneficial effect is that it enables the determination of the thickness of the transparent layer of the crucible to be inspected.

[0021] In addition to the technical problems solved by the present invention, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that the present invention can solve, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is an application diagram of an embodiment of the visual inspection system for quartz glass crucibles of the present invention.

[0023] Figure 2 This is a structural front view of an embodiment of the visual inspection system for quartz glass crucibles of the present invention.

[0024] Figure 3 This is a structural side view of an embodiment of the visual inspection system for quartz glass crucibles of the present invention.

[0025] Figure 4 This is a top view of the structure of an embodiment of the visual inspection system for quartz glass crucibles of the present invention.

[0026] Figure 5 This is a flowchart of an embodiment of the visual inspection method for quartz glass crucibles of the present invention.

[0027] Figure 6 This is a point cloud schematic diagram of an embodiment of the visual inspection method for quartz glass crucibles of the present invention.

[0028] Figure 7 This is a flowchart of another embodiment of the visual inspection method for quartz glass crucibles of the present invention.

[0029] Figure 8 This is a point cloud schematic diagram of another embodiment of the visual inspection method for quartz glass crucibles of the present invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. It should be noted that these descriptions of embodiments are intended to aid in understanding the invention and do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] See Figures 1 to 4The figure shows a binocular vision-based visual inspection system for quartz glass crucibles. The system is positioned above the crucible 100 to be inspected. This system is used to detect the number, size, depth, and thickness of bubbles in the transparent layer of the crucible 100.

[0032] In specific implementation, a displacement robotic arm 200 is located beside the crucible 100 to be inspected. The displacement robotic arm 200 is equipped with the quartz glass crucible visual inspection system. The connecting end of the displacement robotic arm 200 is fixedly connected to the connecting bracket 1. The displacement robotic arm 200 allows adjustment of the relative position between the quartz glass crucible visual inspection system and the crucible 100 to be inspected. For example, it allows adjustment of the relative height between the quartz glass crucible visual inspection system and the crucible 100 to be inspected.

[0033] The quartz glass crucible visual inspection system includes: a connecting bracket 1, a binocular camera 2, a first-line laser 3, and a second-line laser 4. The connecting bracket 1 houses the binocular camera 2, the first-line laser 3, and the second-line laser 4. During visual inspection, the binocular camera 2, the first-line laser 3, and the second-line laser 4 are all pointed towards the transparent layer of the crucible 100 to be inspected. The first-line laser 3 and the second-line laser 4 are configured such that the first-line laser 3 forms an outer surface first-line light spot and an inner surface first-line light spot, respectively, at positions on the outer and inner surfaces of the transparent layer of the crucible 100 to be inspected. The second-line laser 4 forms an outer surface second-line light spot and an inner surface second-line light spot, respectively, at positions on the outer and inner surfaces of the transparent layer of the crucible 100 to be inspected. The outer surface first-line light spot is not collinear with the outer surface second-line light spot, and the inner surface first-line light spot is not collinear with the inner surface second-line light spot. The binocular camera 2 is configured such that its field of view at least covers the transparent layer of the crucible 100 under inspection. Thus, the binocular camera 2 can sample the first line spot on the outer surface, the second line spot on the outer surface, the first line spot on the inner surface, the second line spot on the inner surface, and the air bubble in the transparent layer of the crucible 100 under inspection.

[0034] In practice, the first line laser 3 and the second line laser 4 are arranged one in front of the other, forming an inward V-shape. The two camera units of the binocular camera 2 are also arranged one on the left and one on the right, forming an inward V-shape.

[0035] In practice, both the first line laser 3 and the second line laser 4 are line lasers.

[0036] Preferably, the quartz glass crucible visual inspection system further includes a camera light source 5. The connecting bracket 1 is equipped with the camera light source 5. The camera light source 5 is used to illuminate the crucible 100 to be inspected, so as to enable the binocular camera 2 to obtain better imaging results.

[0037] In specific implementation, the camera light source can be a ring light source.

[0038] Preferably, the positions and angles of the first line laser 3, the second line laser 4, the binocular camera 2, and the camera light source can all be adjusted.

[0039] In specific implementation, the first line laser 3 and the second line laser 4 are mounted on the connecting bracket 1 via a rotating laser mount. The binocular camera 2 is mounted on the connecting bracket 1 via a camera mount supporting lateral displacement and rotation. The camera light source 5 is mounted on the connecting bracket 1 via a light source mount supporting vertical displacement.

[0040] Combination Figure 5 The figure illustrates a visual inspection method for quartz glass crucibles. This method is implemented using a quartz glass crucible visual inspection system. The method can be used to detect the number, size, and depth of bubbles in the transparent layer of the crucible under inspection.

[0041] The visual inspection method for quartz glass crucibles includes the following steps, which are performed sequentially:

[0042] Step S1: The first line laser 3 forms a first line spot on the outer surface of the transparent layer of the crucible 100 under inspection. The second line laser 4 forms a second line spot on the outer surface of the transparent layer of the crucible 100 under inspection. The binocular camera 2 samples the first line spot, the second line spot, and the air bubble in the transparent layer of the crucible 100 under inspection.

[0043] Step S2: Based on the first and second line light spots on the outer surface, determine the fitting surface of the outer surface of the transparent layer of the crucible 100 to be inspected: see [link to relevant documentation]. Figure 6 In the point cloud diagram, the point cloud 300 of the first line spot on the outer surface and the point cloud 400 of the second line spot on the outer surface are visible. The outer surface fitting surface 500 of the transparent layer is constructed from the point cloud 300 of the first line spot on the outer surface and the point cloud 400 of the second line spot on the outer surface.

[0044] Step S3: Determine the depth of the bubble in the transparent layer of the crucible 100 under inspection based on the positional relationship between the bubble and the fitted surface of the outer surface of the transparent layer. (See also...) Figure 6In the point cloud diagram, the transparent layer bubble 600 of the crucible 100 under inspection is visible. The depth of the transparent layer bubble in the crucible 100 under inspection is calculated. The depth of the transparent layer bubble in the crucible 100 under inspection is equal to the distance from the transparent layer bubble 600 to the fitting surface 500 on the outer surface of the transparent layer.

[0045] Step S4: Determine the number and size of the bubbles in the transparent layer of the crucible 100 to be inspected based on the bubbles: use existing algorithms for identification.

[0046] Preferably, in order to detect air bubbles in the transparent layer of the crucible 100 at various locations, the positions and / or angles of the first line laser 3, the second line laser 4, and the binocular camera 2 can be adjusted to traverse the bottom wall position, side wall position, chamfer position, and other positions of the crucible 100.

[0047] Combination Figure 7 The figure illustrates another visual inspection method for quartz glass crucibles. This method is also implemented using the same quartz glass crucible visual inspection system. This method can be used to detect the thickness of the transparent layer of the crucible under inspection, etc.

[0048] The visual inspection method for quartz glass crucibles includes the following steps, which are performed sequentially:

[0049] In step S1, the first line laser 3 forms a first line spot on the outer surface and a first line spot on the inner surface of the transparent layer of the crucible 100 under inspection, respectively. The second line laser 4 forms a second line spot on the outer surface and a second line spot on the inner surface of the transparent layer of the crucible 100 under inspection, respectively. The binocular camera 2 samples the first line spot, the second line spot, the first line spot, and the second line spot on the inner surface.

[0050] Step S2: Based on the first and second light spots on the outer surface, determine the fitting surface of the outer surface of the transparent layer of the crucible 100 under inspection. Based on the first and second light spots on the inner surface, determine the fitting surface of the inner surface of the transparent layer of the crucible 100 under inspection: See [link to relevant documentation]. Figure 8In the point cloud diagram, the point cloud 300 of the first line spot on the outer surface, the point cloud 400 of the second line spot on the outer surface, the point cloud 700 of the first line spot on the inner surface, and the point cloud 800 of the second line spot on the inner surface are visible. The outer surface fitting surface 500 of the transparent layer is constructed from the point cloud 300 of the first line spot on the outer surface and the point cloud 400 of the second line spot on the outer surface. The outer surface fitting surface 900 of the transparent layer is constructed from the point cloud 700 of the first line spot on the inner surface and the point cloud 800 of the second line spot on the inner surface.

[0051] Step S3: Determine the thickness of the transparent layer of the crucible 100 to be inspected based on the positional relationship between the fitting surface of the outer surface of the transparent layer and the fitting surface of the inner surface of the transparent layer. (See [link]) Figure 8 The thickness of the transparent layer of the crucible 100 to be inspected is calculated. The thickness of the transparent layer of the crucible 100 to be inspected is equal to the distance from the fitting surface 500 of the outer surface of the transparent layer to the fitting surface 900 of the inner surface of the transparent layer.

[0052] Preferably, in order to detect the thickness of the transparent layer of the crucible 100 at various positions, the positions and / or angles of the first line laser 3, the second line laser 4, and the binocular camera 2 can be adjusted to traverse the bottom wall position, side wall position, chamfer position, and other positions of the crucible 100.

[0053] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A visual inspection method for quartz glass crucibles based on binocular vision, implemented through a visual inspection system for quartz glass crucibles, the visual inspection system for quartz glass crucibles comprising: The device consists of a first-line laser, a second-line laser, and a binocular camera connected to a support frame. During visual inspection, the first line laser, the second line laser, and the binocular camera are all pointed at the transparent layer of the crucible under inspection. The first line laser and the second line laser are configured such that the first line laser forms a first line spot on the outer surface and a first line spot on the inner surface of the transparent layer of the crucible under inspection, respectively; the second line laser forms a second line spot on the outer surface and a second line spot on the inner surface of the transparent layer of the crucible under inspection, respectively. The binocular camera is configured such that its field of view at least covers the transparent layer of the crucible under inspection. The system is characterized by including: Step S1: The first line laser forms a first line spot on the outer surface of the transparent layer of the crucible under inspection, and the second line laser forms a second line spot on the outer surface of the transparent layer of the crucible under inspection. The binocular camera samples the first line spot, the second line spot, and the bubble in the transparent layer of the crucible under inspection. Step S2: Determine the fitting surface of the outer surface of the transparent layer with respect to the outer surface of the crucible to be inspected based on the first line spot and the second line spot on the outer surface. Step S3: Determine the depth of the bubble in the transparent layer of the crucible under inspection based on the positional relationship between the bubble and the fitted surface of the outer surface of the transparent layer; and, Step S4: Determine the number and size of the bubbles in the transparent layer of the crucible to be inspected based on the bubbles in the transparent layer.

2. The visual inspection method for quartz glass crucibles according to claim 1, characterized in that, The quartz glass crucible visual inspection system further includes a camera light source mounted on a connecting bracket, the camera light source being used to illuminate the crucible to be inspected.

3. The visual inspection method for quartz glass crucibles according to claim 2, characterized in that, The camera uses a ring light source.

4. The visual inspection method for quartz glass crucibles according to claim 1, characterized in that, The first line laser and the second line laser are arranged in a V-shape, one in front of the other; the two camera units of the binocular camera are also arranged in a V-shape, one on the left and one on the right.

5. The visual inspection method for quartz glass crucibles according to claim 1, characterized in that, Both the first and second line lasers are line lasers.

6. The visual inspection method for quartz glass crucibles according to claim 1, characterized in that, The connecting bracket is fixed to the displacement robotic arm.

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