Classification and color selection of light source in machine vision
Machine Vision Light source is one of the most important parts of machine vision system. Machine Vision Light source directly affects the quality of picture. This paper focuses on the classification of machine vision light source, and the selection of the color of machine vision light source.
Classification of Machine Vision Light Sources
1. Ring Light Source: provide different light angle, different color combination, can highlight the three-dimensional information of the object; high-density LED array, high brightness; a variety of compact design, to save installation space; solve the problem of Diagonal Illumination Shadow; Optional Diffuser Plate Light Guide, uniform diffusion of light. Application: PCB testing, IC component testing, microscope lighting, LCD calibration, plastic container testing, IC print checking.
2. BACKLIGHT: high-intensity backlight is provided by high-density LED array, which can highlight the outline features of the object, especially suitable for the microscope platform. Red-white dual-purpose backlight, red-blue multi-purpose backlight, can be adjusted to different colors, to meet the different objects of multicolor requirements. Application areas: Mechanical Parts Measurement, electronic component, IC appearance detection, film stain detection, transparent object scratch detection.
3. Bar Light Source: is the preferred light source of larger square structure, color can be matched according to demand, free combination, lighting angle and installation adjustable at will. Application: Metal Surface Inspection, image scanning, surface crack detection, LCD panel detection, etc. .
4. COAXIAL light source: Can eliminate the shadow caused by the uneven surface of the object, thus reducing interference; part of the use of spectroscope design, reduce light loss, improve imaging clarity, uniform illumination of the object surface. Application: The series of light source is suitable for high reflectivity objects, such as metal, glass, film, Wafer surface scratch detection, chip and Silicon Wafer damage detection, Mark point positioning, packaging bar code identification.
5. Linear Light Source: ultra-high brightness, using cylindrical lens focusing, suitable for continuous detection of various pipeline occasions. APPLICATIONS: Array Camera Lighting Special, AOI special.
6. Point Light Source: High Power LED, small size, high luminous intensity; Optical Fiber Halogen lamp replacement, especially suitable for the lens of coaxial light source, etc. . Application: Suitable for telecentric lens use, for chip detection, Mark Point positioning, Wafer and LCD glass substrate correction.
Machine Vision Light Source Color Selection
White Light Source (W-RRBWhitehLightight source is usually defined by color temperature, high color temperature blue (cool color temperature 5000K) , low color temperature red (warm color temperature 3300 and 5000K) , between the called intermediate color, white light source applicability, high brightness, more use in taking color images.
Blue Light Source (B) : Blue Light source wavelength in 430-480, suitable for products: silver background products (such as sheet metal, turning parts, etc.) , metal printing on film.
Red Light Source (R) : The wavelength of Red Light source is usually between 600-720, can pass through some dark objects, such as black substrate transparent soft plate hole location, Green Circuit Board Line Detection, transparency film thickness detection, etc. , using red light source can improve contrast.
Green Light Source (G) : Green Light Source Wavelength 510-530, between red and blue, mainly for red background products, silver background products.
On the problem of machine vision light source, this paper focuses on the classification and color selection of machine vision light source. It can be seen that there are many different classifications of machine vision light source, these classifications have their own characteristics and applicable environment, as for color selection also need to be based on specific requirements to choose.