An electronic paper display was fabricated by injecting electronic ink, including white and black particles coated by positive and negative charge control agents (CCA), respectively, into closed cells surrounded by micro-barriers. These two types of charged, colored particles are easily damaged or their charging value can be changed by the injection process; therefore, the electrical and optical properties of the image panel fabricated by the injection method were estimated in this study. The active particle-loading method, proposed as a new electronic ink injection process, was applied, and the electro-optical properties of the resulting three-electrode-type e-paper image panel were analyzed. The reflection rate of the white image-panel fabricated with our new injection method was 24.7%, while that of the same panel fabricated with a previously reported injection method was 19.8%. In addition, the response time was improved by about five times compared to those reported in other publications.
A three-electrode type reflective display (electronic paper) is designed to apply an independent electric field to each three electrodes of the cell including two electric-type of particles and electrically neutral color fluid, so single color realization is possible. In particular, the movement of particles and optical properties are decided by the electric field between two electrodes on the lower substrate. So, the effect of electric field by the distance between two electrodes on the lower substrate is studied with electrode spacing with 10 μm, 15 μm, 20 μm, and 25 μm. By our experimentation, the driving voltage induces more reliable movement of charged particles and the optical properties as compared with the threshold voltage. We ascertain the single color realization and non-inverted particle separation is possible. So the more desirable optical properties are observed in case of the short electrode like 10 μm.
We realize a color reflective display without any color filter and sub-pixelation concept, by which the full or single color realization is basically impossible. In this study, we use a 3-electrode on the lower substrate with indium tin oxide (ITO) glass. The width of a rib is 30 ㎛, a cell size is 150 ㎛ × 150 ㎛, and the space of lower electrodes is 10 ㎛. To get the single color, we drive this panel by a identical algorithm based on the movement of charged particle in color fluid within a cell with hermetic seal. According to the driving method, the lifetime of panel is different.