The present invention relates to an electro-optic passive display device.
It is known, in such devices, that for physiological reasons, the reading of a display is facilitated if the information is displayed, during the day, in dark characters on a light background, and, during the night, in light characters on a dark background.
In the nematic liquid crystal display devices having a field effect, such display conditions can be obtained while rotating an upper polarizer at an angle of 90.degree. when one changes from the day reading to night reading. This solution has drawbacks due to the fact that it is difficult to reconcile the movement of the polarizer with the seal of the display device. Also, because polarizers are very sensitive to humidity, it is necessary to insulate or encapsulate them completely.
The purpose of the present invention is to furnish a solution to this problem.
USPTO Backgrounds
USPTO Backgrounds