Patent ID: 8570260

Claim:
A method of controlling a liquid crystal display (LCD) within a field device for operation in cold temperature, the method comprising: providing a first electrical power level to the LCD for operating the LCD; providing an electrical signal to the LCD to update information displayed on the LCD; providing a first temperature setpoint; measuring an ambient temperature proximate the LCD; providing a second electrical power level to the LCD when the measured ambient temperature is lower than the first temperature setpoint; setting an update interval to a first length of time, wherein the step of providing the electrical signal to the LCD to update information displayed on the LCD is performed periodically at the update interval; providing a second temperature setpoint; setting the update interval to a second length of time when the measured ambient temperature is lower than the second temperature setpoint, wherein the second length of time is longer than the first length of time; providing a third temperature setpoint; and wherein the step of providing the electrical signal to the LCD provides information to update only a portion of the LCD when the measured ambient temperature is lower than the third temperature setpoint.