Patent ID: 6515942
Filing Date: 2003-02-04
Classification: G02F,G04G

Abstract:
A display assembly, including:an upper and a lower display device, the upper display device being superposed over the lower display device and including a display cell that is transparent in a first state to make the lower display device visible, said display cell displaying an item of data in a second state; control means for supplying a control voltage to the cell to cause it to switch from the first state to the second state and vice versa; wherein said display cell is a liquid crystal cell that is diffusing or reflective in the second state; and wherein said display cells is a liquid crystal cell selected from the group consisting of (1) twisted nematic liquid crystal cells having a linear polarizer in front of the liquid crystal cell and a quarter-wave plate and a cholesteric film placed in succession behind the cell, and (2) twisted nematic liquid crystal cells having a first polarizer placed in front of the cell, and a reflective polarizer placed behind the cell.