A Measurement Method for Chromaticity and Photometric Quantity of Laser Displays

Abstract

In recent years, an increasing number of displays have been adopting lasers to benefit from their high color reproducibility, enhanced energy efficiency and small size. As the use of lasers in displays is growing, the demand for precise measurement of their chromaticity and photometric quantity is rising in order for manufacturers to ensure their display quality. However, tristimulus-value direct-reading method, which has been a commonly-used measurement method in the optical industry, cannot meet the required chromaticity accuracy of ±0.0150 due to lasers’ extremely narrow spectra. To solve the measurement problem, we propose a new measurement method developed for laser displays, which is called the discrete centroid wavelength method (DCWM). The DCWM calculates chromaticity and photometric quantity based on the centroid wavelength and radiometric quantity of lasers, which is a different measurement principle from the tristimulus-value direct-reading method. Our numerical analysis which simulated measurements of red, green and blue lasers by the DCWM showed that the DCWM has a chromaticity accuracy of 0.0065 and meets the required accuracy. We concluded that the DCWM is an appropriate measurement method for laser displays.