1. Field of the Invention
This invention relates to a displaying medium containing a binder and a liquid crystal composition dispersed in the binder.
2. Described of the Related Art
Recently, chances for reading electronic information easily obtained instead of documents or images printed on paper are increasing accompanied with rising of working speed of personal computer, spreading of the infrastructure of net work and growing and coat lowering of data storage means.
For such the means for reading the electronic information, light emission type displays such as a usual liquid crystal display, a CRT and a newly introduced organic EL display are mainly employed. However, it is necessary to watch the displaying means for relatively long time particularly when the electronic information is document information. Therefore, such the means cannot be considered as means suitable for human. It is general known as the shortcomings of the light emission type display that fatigue of eyes is caused by flicker, the displaying means is inconvenient for conveying, the posture of the observer is limited for focusing on the still image and the consumption of electric power is increased for reading for a long duration.
A reflection type display utilizing external light which consumes no electric power for holding the image (memory type) is known as the displaying means for compensation such the shortcomings. Among the reflection type displays, a system in which a liquid crystal composition is dispersed in a binder in a form of oil droplet, so-called as a polymer dispersion type liquid crystal or a scattering liquid crystal, is disclosed in Tokkai 2003-302625, Tokkai Hei 7-287214 and 9-218421 and Tokkai 2000-98326.
As a result of detailed investigation by the inventors on the techniques disclosed in the above patent documents, some problems are found, that the variation in the displaying properties probably caused by shortage of the mechanical strength occurs when the displaying means was stored for long period under a severe condition such as high temperature or high humidity or subjected to a folding test, and the variation probably caused by dissolving of the component for hardening into the liquid crystal composition when a non-aqueous type UV hardening resin or a thermoplastic is employed for raising the mechanical strength, even though the image can be displayed by utilizing the light scattering state and the light penetration state of the liquid crystal. Moreover, the problems relating the storage ability under the sever conditions and the resistivity against folding, and the constitution relating to the invention are not described and suggested in the above documents at all.
USPTO Backgrounds
USPTO Backgrounds