Liquid crystal sheet thermometer

TL;DR: In this paper, the authors measured the response time when a dipole is inverted in ferroelectric phase from the peak of a polarization inverting current, using data on the temperature and response time.

Abstract: PURPOSE:To find accurate temperature with good response by applying a rectangular or triangular voltage, measuring the response time when a dipole is inverted in ferroelectric phase from the peak of a polarization inverting current, and using data on the temperature and response time. CONSTITUTION:When a control means 41 commands a voltage applying means 20 to apply a voltage to a specific position of a sheet type temperature sensing means 10, an applying means 20 applies the rectangular wave, etc., to an electrode line corresponding to the specific position between electrodes 14 and 15 according to the command. When the rectangular wave voltage, etc., is applied from the applying means 20, the dipole of liquid crystal molecules of the liquid crystal cell at the part applied with the voltage is inverted as the polarity of the voltage is varied so that the polarization inverting current flows to the liquid crystal cell. A current variation measuring means 30 measures the current polarization inverting current and sends the result to the calculation part 42 of a processing part 40. The calculation part 42 finds the response speed tm or tw of the liquid crystal cell from the current variation sent from a varying means 30 and finds the temperature corresponding to the response speed tm or tw from the response-speed/temperature characteristic data of the ferroelectric high polymer liquid crystal which is stored previously in a data storage means 43.