High VisionCon2019 !
Industry big curry machine visual light source practice!
What are the focus of machine vision worth tapping in the areas of "advanced imaging technology" and "systems and applications"? What are the latest productand and technology solutions in the industry?
June 21, VisionCon 2019 (Suzhou Station) Yu Yun is still dazzling, many topics to arouse the interest of readers, the impact of the conference technology whirlwind is still fermenting! This issue of the content of the press conference, we approached the machine visual light source together, to see how Wardup tracking the development trend of light source, the product and light source characteristics closely combined?
Speaker Su Hailong, from July 2005 to December 2014, was the deputy general manager of Dongguan City Wordop Instrument Co., Ltd., founded in December 2014 and served as deputy general manager of Dongguan Wordop Automation Technology Co., Ltd. In 2017, Wardup opened an office in Suzhou and is a manufacturer of machine vision light sources and light source controllers.
Deputy General Manager
Dongguan Wordop Automation Technology Co., Ltd.
A week before the VisionCon2019 (Suzhou Station) meeting, Su had just exchanged the characteristics of light sources in Hangzhou and Zhejiang University. "About the characteristics of the light source, much more than said these, " Su always modestly said at the scene: "I am only in the actual 'crawling and rolling'! "We see that the site PPT lists the different characteristics of light sources such as light path, angle, uniformity, spectroscopy, polarization and strobe control, and Wardup has a range of products that give us more choice and space in the choice of light source."
Collimation and Diffuse Light
"Before the textbook only direct light and diffuse light, and now our visual environment is much more than these two! "Straight-up light, light beads directly irradiated products, suitable for the direction of high requirements of the scene;
On-site large-screen PPT shows the effect of different application scenarios for optical path collimating light source to give us a more intuitive comparison. For example, for relay pin flatness detection, the use of optical path collimating light source, can quickly locate the pin position, easy to handle the algorithm;
For example, pan-panel AOI detection, the use of custom parallel light source, can be seen bumps, creases and other defects. The uniformity of scattering light is very high, which will sacrifice a certain brightness, but a more uniform light-emitting surface of the material reflected by the mirror can effectively avoid the lamp beads on the surface of the object under test.
High parallel linear light source, can be combined with the coaxial light applied by the wire array camera, using the standard mold molding, to ensure structural stability, the brightness of the light source uniformity of up to 90%. Mainly used in mobile phone glass cover plate appearance detection, LCD substrate glass AOI detection, PCB bare plate AOI detection, mobile phone steel sheet / graphite sheet appearance detection, film type appearance detection.
Sometimes, the places we need to detect are not the same surface as the places that don't need to be detected, some places diffuse, some places mirror reflection. At this point, the concept of bright field lighting and dark field lighting needs to be introduced. Bright field illumination is to use the light source directly to the object to observe, dark field illumination is through its it is reflected by the object or diffraction of the light to observe, forming two distinct ways of lighting.
Three typical lighting methods: bright field lighting, dark field lighting and backlighting. In direct-shooting lighting, many of the materials under test are different, resulting in the loss of surface feature information. The backlight can distinguish between the light transmission and the spot of impermeable light, the place of light transmission is white, the spot is not transparent black. When using the backlight, the light should be used as far as possible to ensure that the light is parallel, to ensure that the light of different intensity does not cause changes in the profile of the object under test, thereby improving the accuracy of the overall detection.
For example, mobile phone cover glass screen pre-screen detection items, the use of multi-angle light source, can clearly detect scratches and other defects. The principle is that the use of forward dark field lighting, through a number of aspherical reflection of the way to achieve transparent workpiece scratch detection.
A utility model exterior patent has been applied for. Mainly used in mobile phone glass cover appearance detection, LCD substrate glass AOI detection, PCB bare plate AOI detection, more industry applications are being explored!
1. Use high uniform backlighting of different sizes, which can be used to detect mura defects of different sizes.
2. Using a high uniform linear light source, you can detect products with high uniformity requirements, and can be backlit imaging.
With the linear light source applied by the wire array camera, the standard mold molding is used to ensure the stability of the structure and the brightness uniformity of the light source reachs 90%. Mainly used in mobile phone glass screen surface defect detection, aluminum foil surface scratch detection, steel plate surface defect detection.
On-site display results, the light source glow length of 500mm, of which 450mm area brightness uniformity of up to 90%.
Complementary colors are the colors that are exactly opposite in the color ring. When you shine a light on an object with complementary colors, the color of the object in the black-and-white camera is close to black. Depending on the color ring, we can achieve the highest level of contrast with the opposite color. For example, when the light is irradiated with cold light, the color will darken, and the color will brighten when the cool light shines on the cool light. When using a color camera, white is usually selected. On-site we also see that for PCB character detection, blue light is fully reflected, the background is white, no characters; Obviously, using a light source of a specific spectrum can increase the contrast of features.
Metal spectre reflectivity. In the field of wavelengths below 600nm, gold and copper have very low specular reflectivity. With wave length (e.g. blue light) LED lighting, the metal image is darker, and the image of the metal surface is relatively bright with the long (e.g. red) LED illumination of the wave length. For example, weld spot detection, the use of blue light source, can improve the contrast of welding points, filter copper wire interference.
Infrared. The use of 1300nm infrared light, the use of infrared penetration strong characteristics, with infrared array camera use, so that the invisible to the naked eye of the fissure becomevisible. Such as the side scratch detection of beverage cans, with ordinary light lighting, pattern interference, with infrared light lighting, long wavelength, through the beverage can surface of the texture. Infrared light ignores the color of the product and the effects of some of its patterns.
Ultraviolet light. For example, anti-counterfeiting label detection, the use of ultraviolet (fluorescent) characteristics, visible anti-counterfeiting labels, the use of ultraviolet light source to detect transparent film, because of the uv light scattering capacity is high, scattered on the surface of the object, can effectively observe the surface of the object, can see the transparent film surface ITO.
Polarizer mirror and polarizing light source, can eliminate the reflective material in one direction of the reflective spot, quickly read information. Therefore, if the product is reflective, the use of polarization light sources may be given priority.
Polarized mirrors can cause 2-3 times the loss of light, so that the camera can not use the high-speed shutter because there is not enough light, in the case of light is slightly inadequate, or even because the camera shakes to take blurry photos. Therefore, polarizing mirror is a good thing, but by no means can always be installed on the lens, we only when necessary will ask it out of the horse!
Strobe control -
High-speed strobe new technology!
Currently, the Wardup controller can be used to control high-speed strobe with peripheral control light sources. In the future direction, the use of intelligent controllers, with the company's high-speed strobe flash source, to achieve high-speed strobe photography.
Compared with the ordinary controller, the brightening module controller can instantly increase the brightness of the light source by more than 3 times, through the external trigger function and high and low level switching, so that the light source flash escent, the light light time can be set at 0-999us.
The highlight of the strobe control is the short response delay! PBT4 strobe time adjustable (0-999us), trigger delay time adjustable (0-999us), light source delay glow time adjustable (0-999us). At the above time, the step is 1us. In addition, external and internal triggers can be triggered externally (frequency 1-20Hz adjustable, not always on, easy to set parameters during debugging, directly for testing). Trigger port, internal use of two-way optical coupling, trigger input, wiring regardless of positive or negative;
"The light of science and technology, create a better future!" "Wordop has the courage to perceive industry challenges, capture industry opportunities, integrate collaboration, work to address key customer needs, continuously build forward-looking light source products and improve light source applicationservices, and broaden the space for future applications of automation equipment."