Study Of RGB LED-based Color Temperature Tunable Microscope Light Source

With the progress of technology, the LED has been applied in different areas. At present, the application research on RGB LED is still in a preliminary stage. And there is still no example in microscope lighting. On the purpose of meeting the requirements for best results when microscope is faced with different objects, this paper put forward a new idea that applied the RGB tri-chromatic LED on microscope lighting. That idea can make full use the RGB LED’s rich color gamut and tunable color temperature characteristics. This paper mainly focuses on the issues of the RGB LED-based color temperature tunable microscope lighting source system, including:light color design, carrying out of hardware and software, modification and simulation of lighting system, etc.Based on LED current research situation and RGB LED’s rich color gamut and tunable color temperature characteristics, the paper analyzes the relativity between the RGB LED lighting source and the color temperature tunable request of microscope illumination; according to the principle of colorimetry, put forward the matching of straight line fitting method and distance comparing method and the downhill simplex algorithm respectively applies to the optimizing of color temperature and duty ratio calculation.Arming at solving the color variation problem in working progress of RGB LED lighting source, the paper design the hardware driving control circuits and software control algorithm. The hardware driving control circuit contents of the MCU circuit, LED PWM driving circuit and the feedback circuit which is used for stability control. The software control uses the suitable PID algorithm, combined with the position type and increment type PID algorithm, for better stability; in order to fit the RGB LED lighting, apply the square light pipe to modification of the Kohler illumination by the means of building the simulation model, and get uniform lighting; through the construction and test of the RGB LED-based microscope light source system, proves that the system research the designing destination that color temperature tunable and good color rendering.In a word, the paper makes the RGB LED-based color temperature tunable microscope light source system come true. That has the certain theory and practical value for both the microscope application and the research of the RGB LED.