Patent attributes
A writing device includes a liquid crystal layer including cholesteric liquid crystal material. There are electrically conductive layers between which the liquid crystal layer is disposed. There is a front writing surface layer that is transparent and a back support layer between which the electrically conductive layers and the liquid crystal layer are disposed. The cholesteric liquid crystal material changes in texture by application of pressure to the front writing surface layer to create an image. A seal confines the cholesteric liquid crystal material between the front writing surface layer and the back support layer. The electrically conductive layers are adapted to enable a voltage waveform to be applied thereto that erases the image. In one aspect, the resilience to bending the writing device is defined by enabling the writing device to be bent to a radius of curvature of 100.0 millimeters for 10 repetitions of the bending and after each of the repetitions of the bending the voltage waveform completely erases the image. In another aspect, the back support layer comprises a first sublayer formed of a flexible polymeric material adjacent to the back electrically conductive layer, a second sublayer comprising a backer that is flexible and thicker and of a different material than the first sublayer and a bonding layer located between the first sublayer and the second sublayer. In yet another aspect, the seal includes an elastomeric material and wherein the front writing surface layer has a thickness in a range of 0.5 to 4.5 mils and the back support layer has a thickness in a range of 0.6 to 34.5 mils.
