Multi-channel Testing System For Spatial Distribution Of Light Sources

In our daily life,artificial light sources are almost ubiquitous.Solid-state lighting is considered as a new light source with great value and brilliant application prospect because of its high luminous efficiency,adjustable spectrum,and long lifetime.It has not only been widely used in the lighting field,but also has been widely used by display devices,wearable devices,and mobile devices.With,the introduction of concepts such as smart lighting and healthy lighting and people’s increasing attention to vision health protection,people’s requirements for light quality of lighting and display devices are increasing.Obtaining reliable and accurate spectral and spatial distribution data for LED devices or other lighting products is a basic requirement for designing and evaluating a good lighting system.However,the current measurement system generally exist disadvantages such as slow speed,lack of spectrum and CCT etc.In order to comprehensively evaluate light sources’ performance,this dissertation propose a multi-channel rapid testing system for measuring three-dimensional spatial distribution of light sources.The principal contents are:1)Design and build a multi-channel rapid test equipment for testing spatial distribution of light sources.The equipment consists of computer,CCD spectrometer,optical multiplexers,motion controllers,rails,sliders,optical fibers and fixtures.Each optical probe can moves around the light source with driving of the sliders and the rails.Lights are collected by the optical probes to the CCD spectrometer through optical multiplexers.2)Develop relevant software based on Borland Delphi 7 visual programming environment.The software communicates with each instrument through RS-232,USB,and other interfaces to set motion parameters,acquisition parameters,and receives or processes measurement results.This Software realize ultrasound positioning,motion control,spectrum measurement,flicker testing and other functions.We also used a standard tungsten halogen light sources to calibrate sixteen-channel light path respectively(optical fiber-optical multiplexer-optical fiber-CCD spectrometer),and obtained the corresponding calibration file for absolute irradiance measurements.3)Through a series of experiments on LED device,warm white LED,cool white LED,and mobile phone screen,the system functions are verified.The spatial distribution of LED device is compared by the system and the LEDGON 100 Goniophotometer respectively,and the results are consistent with each other;We also compare this system with IS Integrating Sphere system by testing LED device,warm white LED,and cool white LED respectively.Furthermore,comparing the spatial distribution of mobile phone screen in normal mode and read mode,we can find out that in the read mode the blue light in the outgoing light of the screen has been refrained greatly.It means the potential blue light damage is reduced.Last,the flicker test of the warm white LED under different power supply frequency are performed to verify the flicker characteristic measurement function of this system.The innovation of the system proposed in this dissertation lies in:① Rapid and real-time Measurement.The system uses multi-channel detection,greatly saves time.② High precision.Probes rotate in three-dimensional space to meet high-precision test requirements.③ Both Luminous and Chromatics properties are measured.The measurement parameters covers various aspects of photometry and colorimetry.④ Convenient and wide applicability.The system can measure different types of lighting and display devices.⑤ Flicker measurement function is integrated.With flicker test,the system enables more comprehensive evaluation for lighting and displays devices.The system can evaluate the spatial characteristics of the light source conveniently and comprehensively,and can well assist the design and development of lighting equipment,thereby promotes the development of lighting sources to a high quality healthy and energy-saving level.