Multichannel Optical Fiber Spectral and Imaging System for Pixel-Level Measurement of Display

This letter proposes a multichannel optical fiber spectral and imaging system, aiming at evaluating the pixel-level optical properties of high definition display efficiently and precisely. The system makes use of 16-channel optical fibers to form a detecting array so that 16 points of a display under test can be measured cyclically by multiplexer and spectrometer and monitored by camera simultaneously. The optical path is reversible for both the light source and the laser positioning, and adjustable along a rail driven by a motor to enable the system to work in either magnification mode or reduction mode. The feasibility and accuracy of the system are verified by comparative experiments of standard light source, LED display, and OLED display, identifying both merits of a single-spot spectroradiometer and an imaging photometer/colorimeter and even more functions like pitch size and color gamut.

I. Introduction

High definition display, especially the self-emitting display like light-emitting diode(LED) or organic light-emitting diode (OLED) display, has stepped into a new era for outdoor or indoor applications [1]–[3]. LED and OLED displays are known for self-emitting, high efficiency, high purity, high contrast ratio, etc. OLED has been widely used in mobile phones, flexible display or AR/VR fields. Mini- or Micro-size LED is able to reach extra-high resolution in display and is regarded as a promising candidate for next-generation display [4]. Photometric and colorimetric properties are fundamental yet essential parameters for evaluating display’s quality [5]–[7]. For high definition displays, it is critically necessary to develop a reliable method to meet the pixel-level evaluation efficiently and accurately [8], [9].