A light inspection method based on line array camera
Through the detection method based on the linear array camera, the liquid area is used as the light source, combined with the camera movement at a fixed distance, the missed detection problem of existing lamp detectors when detecting tiny foreign objects and cilia is solved, achieving higher detection accuracy and Simplified parameter settings improve the detection rate of foreign objects.
Patent Information
- Application Number
- CN202010581763.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-06-23
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2040-06-23
AI Technical Summary
When detecting foreign objects inside liquid agents, existing lamp detectors have poor detection of tiny foreign objects, white blocks and cilia, and are prone to missed detection, especially in the interference and blind areas caused by mirror effects and divergence of the light source. question.
The detection method based on the linear array camera is adopted to make the liquid area illuminate by illuminating the light source, and the linear array camera and light source are kept at a fixed distance, and the image is collected to avoid the light source directly illuminating the bottle wall, achieving uniform illumination and image scanning of the entire container area , eliminate light interference and blind spots.
It improves the detection accuracy of tiny foreign objects, white blocks and cilia, reduces the missed detection rate, simplifies the equipment parameter debugging process, achieves a globally consistent image brightness, and improves the detection rate of foreign objects.
Smart Images
Figure CN111721775B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of pharmaceutical equipment detection, and in particular is a light detection method based on a linear array camera. Background Art
[0002] Fully automatic light inspection machines are used to detect visible foreign matter in medicines produced by pharmaceutical factories. Existing light inspection machines for detecting foreign matter inside liquid medicines are basically based on solutions such as lighting from the bottom of the bottle and taking pictures from the side of the camera; or lighting from the back of the bottle and taking pictures from the opposite side of the camera. The advantages and disadvantages of these two solutions are as follows:
[0003] Lighting the bottom of the bottle: When the light source shines on the surface of the foreign object, the foreign object will reflect the light source to the outside, and the image features will be brighter than the blank area. This solution is effective in detecting tiny foreign objects, white blocks, cilia and other foreign objects. The disadvantages are too much interference and blind spots. The light source will form a mirror effect on the surface of the liquid. When the liquid surface shakes, there will be moving bright spots at the bottom; the light source is divergent and cannot be controlled to be exactly the same as the diameter of the bottle. The light source will extend to the surrounding bottles, resulting in light interference at the bottle boundary; due to direct illumination from the bottom and the reflection effect of the liquid surface, the imaging is generally bright at the bottom and near the liquid surface, while the middle area is dark, which will make it impossible to detect the white area near the liquid surface and the bottom. The image features in the middle area are not obvious due to insufficient brightness, resulting in missed detection.
[0004] Lighting the bottle from the back: When the light source penetrates the bottle, if there is a foreign object, it will block part of the light source, and the image features will be darker than the blank area. The advantage of this solution is that it has strong anti-interference ability and good detection effect on dark foreign objects. The disadvantage is that it is not effective for detecting foreign objects such as cilia, small glass, and white blocks, because these foreign objects are very thin or near-transparent, and will be corroded under backlight, making them completely invisible, or the light source can directly penetrate, and the contrast with the surrounding area is not obvious, resulting in missed detection. Summary of the invention
[0005] In view of the above problems, the present invention provides a light inspection method based on a linear array camera, which is implemented based on a linear array camera and is used to detect foreign matter inside a liquid. It is superior to existing bottom light and backlight detection solutions in detecting tiny foreign matter, white blocks, cilia, floating objects on the liquid surface and other foreign matter and resisting light interference, and can also simplify the equipment parameter debugging process.
[0006] To achieve the above object, the technical solution adopted by the present invention is: a light inspection method based on a linear array camera, comprising the following steps:
[0007] 1) The light from the light source is irradiated onto the light-transmitting container, so that the area of the liquid in the light-transmitting container illuminated by the light source is illuminated, forming a liquid light source; the light from the liquid light source is used to illuminate other liquid areas in the light-transmitting container;
[0008] 2) The collection surface of the linear array camera is staggered from the liquid light source, and the distance between the linear array camera and the light source is kept fixed; the linear array camera and the light source form a whole, move relative to the light-transmitting container, and use the linear array camera to scan and collect images of the area illuminated by the liquid light source in the light-transmitting container to achieve the acquisition of foreign body feature images.
[0009] As a preferred embodiment of the present invention, the line array camera and the light source are at different heights.
[0010] As a preferred embodiment of the present invention, the linear array camera and the light source are fixed on the same mounting member, and the linear reciprocating motion mechanism controls the mounting member to reciprocate in a direction parallel to the bottle body, and the linear array camera is used to scan and collect images of the light-transmitting container.
[0011] As a preferred embodiment of the present invention, a plurality of line array cameras are provided, distributed vertically or horizontally.
[0012] As a preferred embodiment of the present invention, the light-permeable container is made of transparent material or translucent material.
[0013] As a preferred embodiment of the present invention, the light from the light source is redirected by a prism, a lens or a mirror to provide supplementary light to the light-transmitting container.
[0014] As a preferred embodiment of the present invention, the light source is in a bar shape.
[0015] Compared with the prior art, the advantages of the present invention are:
[0016] 1. Linear array cameras, because the positions of the light source and the camera are fixed, the brightness of the captured images is highly consistent when the brightness of the light source remains unchanged. Unlike area array cameras, due to the attenuation of the light source, the areas close to the light source are bright and the areas far from the light source are dark. Solutions based on line array cameras will not lose foreign body features due to images being too bright or too dark, and can effectively eliminate missed detections.
[0017] 2. When the image brightness is consistent, global detection parameters can be set for the entire image without setting different detection parameters by layer or region. This can effectively simplify the parameter setting process of the light inspection machine and achieve fast product switching.
[0018] 3. There is no light interference or blind spot in any area of the entire bottle, which can effectively improve the detection rate of foreign matter. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 A schematic diagram of the linear array camera in the present invention starting to descend;
[0020] Figure 2It is a schematic diagram of the linear array camera starting to rise in the present invention;
[0021] In the figure: 1. light-transmitting container; 2. liquid light source; 3. light source; 4. line array camera; 5. mounting part. DETAILED DESCRIPTION
[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present invention.
[0023] See also Figure 1 to Figure 2 In a specific implementation, a light inspection method based on a linear array camera includes the following steps:
[0024] 1) The light from the light source 3 is irradiated onto the light-permeable container 1, so that the area of the liquid in the light-permeable container 1 irradiated by the light source is illuminated, forming a liquid light source 2; the light from the liquid light source 2 is used to illuminate other liquid areas in the light-permeable container 1; Figure 1 As shown, the liquid light source 2 is in the shape of a pancake, which illuminates the area above and below the liquid light source 2 in the light-transmissive container 1 .
[0025] 2) The collection surface of the linear array camera 4 is staggered from the liquid light source 2, and the distance between the linear array camera 4 and the light source 3 is kept fixed; the linear array camera 4 and the light source 3 form a whole, move relative to the light-transmitting container 1, and the linear array camera 4 scans and collects images of the area illuminated by the liquid light source 2 in the light-transmitting container 1 to achieve the acquisition of foreign body feature images.
[0026] like Figure 1-2 As shown, in order to ensure that the irradiation surface of the light source 3 does not affect the scanning of the line array camera 4, as a preferred embodiment of the present invention, the line array camera 4 and the light source 3 are at different heights.
[0027] like Figure 1-2 As shown, in order to keep the light brightness at the scanning position of the line array camera 4 unchanged, as a preferred embodiment of the present invention, the line array camera 4 and the light source 3 are fixed on the same mounting member 5, and the linear reciprocating motion mechanism controls the mounting member 5 to move back and forth in a direction parallel to the bottle body, and the line array camera 4 is used to scan and collect images of the light-transmitting container 1.
[0028] In order to improve the acquisition accuracy and efficiency, as a preferred embodiment of the present invention, a plurality of line array cameras 4 are provided, which are distributed vertically or horizontally.
[0029] In order to facilitate the light to penetrate into the liquid in the light-permeable container 1, as a preferred embodiment of the present invention, the light-permeable container 1 is made of transparent material or translucent material.
[0030] As a preferred embodiment of the present invention, the light from the light source 3 is redirected by a prism, a lens or a mirror to provide supplementary light to the light-transmitting container 1 .
[0031] As a preferred embodiment of the present invention, the light source 3 is in a strip shape. The use of a strip light source can make the liquid in the light-permeable container 1 form a thinner liquid light source, reduce the white background area, and increase the detection range.
[0032] Design principle of the present invention:
[0033] like Figure 1 As shown, the light-transmitting container is a light-transmitting glass or plastic bottle containing liquid; the light source is used in conjunction with the linear array camera, and is usually a long strip light source, such as a strip LED light source, a laser light source, etc.
[0034] Generally speaking, line array cameras use coaxial light and other technologies to make the light source and the camera CCD at the same vertical height. In this case, take a glass bottle as an example: when the light source shines on the outer arc wall of the glass bottle, due to the mirror effect of the glass and liquid, the area near the center of the bottle wall will reflect light, while the boundary area will refract light; this will cause the collected image to be an unbalanced image with bright light in the middle and darker boundaries; and foreign matter in the bottle is invisible. Therefore, the common solution for detecting liquids is back or bottom lighting, and solutions based on line arrays are rare.
[0035] Implementation scheme of this patent:
[0036] The light source uses a high-brightness light source, which is parallel to the light-transmitting container. The liquid area illuminated by the light source will be highlighted, which is equivalent to a surface light source with the same diameter as the bottle body (hereinafter referred to as a liquid light source). The liquid light source will irradiate light upward and downward, which is equivalent to installing a surface light source with the same diameter as the bottle body in the area. Foreign objects illuminated by the liquid light source will reflect light to the outside, showing a highlight feature.
[0037] The light source and CCD of the linear array camera are not at the same vertical height, but are staggered at one height. At this time, what the linear array camera collects is no longer a reflective image with bright center and dark border, but a secondary illumination area illuminated by the liquid light source. Since there is no direct illumination from the light source in this area and it avoids the bottle wall, the illumination is balanced and there is no light interference, which is suitable for detecting tiny foreign objects.
[0038] The specific detection adopts the general scheme of the light inspection machine, which stops rapidly after rotation, and the foreign matter inside continues to move under the action of inertia. More than 2 images are collected for comparison. The places where the image brightness is different are foreign matter. In this patent, the linear array camera and the light source are fixed on the same support plate, and move in a direction parallel to the bottle body. Each movement can collect a complete bottle body image. More than 2 images are collected, and the places where the image has changes in brightness are foreign matter.
[0039] 1. The material of the detection target of this patent is not limited to glass. All translucent or semi-translucent materials, such as glass, plastic, film products, etc., are protected by this patent.
[0040] 2. This patent is not limited to liquid medicines, and the types and industries of detection targets are not restricted. Typical products such as ampoules, oral liquids, glass infusions, plastic bottle infusions, soft bag infusions, row medicines, various water beverages, alcoholic beverages, health drinks, etc. are all protected by this patent.
[0041] 3. The shape of the light source is not limited. Light sources of various shapes and parameters are all protected by this patent;
[0042] 4. The light source control method is not restricted. Various light source control methods such as constant light, strobe, and timed trigger are all protected by this patent;
[0043] 5. This patent is not limited by the color and wavelength of the light source. All wavelengths and light source colors are protected by this patent;
[0044] 6. This patent is not limited by the combination of linear array cameras. For example, multiple linear array cameras are distributed left and right or up and down; or a single or multiple linear array cameras are angled to illuminate and collect images. All of these are protected by this patent.
[0045] 7. Changing the direction of the light source through special prisms, lenses, or optical devices to ultimately achieve the same effect as this solution is also protected by this patent;
[0046] 8. The detection area of this patent is not limited. The liquid surface, bottle bottom, bottle surface and internal foreign matter are all within the protection scope of this solution.
[0047] 9. Regardless of where the camera or light source is placed around the object being inspected and at any angle, as long as the same or similar lighting effect of this patent is achieved, it is also protected by this patent.
[0048] 10. The basic principle of any combination of camera and light source is still to use the light source and camera in a staggered manner, so that the liquid becomes the light source, and the use of the linear array camera to capture images at the same time is protected by this patent.
[0049] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.
[0050] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.
Claims
1. A light inspection method based on a linear array camera, characterized in that: The steps include: 1) Light from a light source (3) is irradiated onto a light-transmitting container (1), so that the area of liquid in the light-transmitting container (1) illuminated by the light source is illuminated, thereby forming a liquid light source (2); and the light from the liquid light source (2) is used to illuminate other liquid areas in the light-transmitting container (1); 2) The collection surface of the linear array camera (4) is staggered with the liquid light source (2), and the distance between the linear array camera (4) and the light source (3) is kept fixed; the linear array camera (4) and the light source (3) form a whole, move relative to the light-transmitting container (1), and use the linear array camera (4) to scan and collect images of the area in the light-transmitting container (1) illuminated by the liquid light source (2), so as to obtain the characteristic image of the foreign matter; The line array camera (4) and the light source (3) are located at different heights; The light source (3) is in the shape of a bar; The linear array camera (4) and the light source (3) are both located on the same side of the light-transmissive container (1).
2. A light inspection method based on a linear array camera according to claim 1, characterized in that: The linear array camera (4) and the light source (3) are fixed on the same mounting member (5), and the linear reciprocating motion mechanism controls the mounting member (5) to move back and forth in a direction parallel to the bottle body, so that the linear array camera (4) performs image scanning and acquisition on the light-transmissive container (1).
3. The light inspection method based on a linear array camera according to claim 1, characterized in that: One or more linear array cameras (4) are arranged perpendicular to the direction of movement thereof.
4. The light inspection method based on a linear array camera according to claim 1, characterized in that: The light-transmissive container (1) is made of a transparent material or a translucent material.
5. The light inspection method based on a linear array camera according to claim 1, characterized in that: The light from the light source (3) is redirected by a prism, a lens or a mirror to provide supplementary light to the light-transmitting container (1).