A High-Speed Measurement Method for Reflective Liquid Crystal Cells Using a Liquid Crystal Polarization-Converting Device

Cell‐parameter measurement system for a liquid‐crystal cell by using a telecentric lens

“…Various methods for measuring the cell thickness, twist angle, and pretilt angle in the LC cells have been reported. [1][2][3][4][5][6][7][8] These methods require a spectrometer 6 or complicated procedures for mechanically rotating the polarizers and/or an optical phase retarder to search for maximum or minimum light intensities. 7,8 The cell parameters of only the cell thickness and/or twist angle can be obtained by the Jones matrix or Stokes parameters.…”

“…We have already reported a high-speed cell-parameter measurement method for determining both cell thickness and twist angle of a reflective LC cell by using a polarization-converting LC device such as a circularly and homogeneously aligned LC cell with a unique property. 5 In this paper, we improve the previous 2-D cell-parameter measurement system [1][2][3][4] and develop an optical sys-tem for perfectly adjusting the wide images of the LC cell and determining a pretilt-angle distribution in addition to both cell-thickness and twist-angle distributions of the LC cell with any pretilt angle. These cell parameters can be obtained by calculating the Stokes parameter equations at several different wavelengths of the transmission light obliquely incident upon the LC cell.…”