Imaging spectrograph for fast LED optical properties measurement

Due to the booming in LED applications, fast and accurate inspection tools to monitor LED quality is necessary. In this paper, we propose two new methods to measure LED optical properties by using imaging spectrograph. Imaging-type spectrograph with high spatial and spectral resolutions is designed for LED wafer measurement. Fiber-type spectrograph with multi-head structure is designed for LED backlight and LED light-bar measurement. Optical properties of LED include chromaticity and luminous intensity, which are measured by following CIE recommendations. The performance of imaging spectrograph is evaluated to meet industrial requirements for LED measurement.