Measurement of modulation transfer functions for liquid crystal displays by rectangular waveform analysis.
We measured modulation transfer functions (MTFs) of liquid crystal displays (LCDs) by rectangular waveform analysis. This method consists of taking a picture of the bar pattern on the display surface with a digital camera, and analyzing the picture with a personal computer. The displays used are LCDs of 1M (about 1 million pixels), 2M, 3M, and 5M, and a cathode ray tube (CRT) display with a pixel number of 5M. Two kinds of 2M displays were used, an in-plane switching (IPS) system and vertical alignment (VA) system, from which liquid crystal operation mode differs. MTFs increased as pixels increased. For the LCDs, MTFs in the horizontal direction were higher than those in the vertical direction except for the 2M VA system. For the LCD of the 2M VA system, MTF in a horizontal direction was equal to MTF in a vertical direction. For the displays with the same number of pixels (5M), MTF of a LCD was higher than that of a CRT display. MTFs of LCDs are influenced by the pixel form, pixel composition, and the liquid crystal operation mode.
Horii
Akiko
A
Graduate School of Medical Sciences, Nagoya University.
Chihara
Aya
A
Ichikawa
Katsuhiro
K
Kodera
Yoshie
Y
Ikeda
Mitsuru
M
Ishigaki
Takeo
T
D003626:Data Display; D007091:Image Processing, Computer-Assisted; D050866:Liquid Crystals