Toner Display is based on an electrical movement of charged particles. Two types of black and white toners charged in the different electric polarity are enclosed in the air space between two electrodes. The particle movement is controlled by the external electric field applied between two transparent electrodes. The black toner is collected to the electrode by an electrostatic force across the insulating layer to display a black image. The white toners can be put back to the counter electrode by applying a reverse electric field, and white solid image is displayed. We have studied on the movement of three color particles independently to display color image in Color Toner Display. Two positively charged color particles with different amount of charge to mass ratio and negatively charged white particles were enclosed in the toner display cell. Yellow, cyan and white images were displayed by an application of voltage.

The photometric orbital elements of an Algol-type eclipsing variable, DI Pegasi, are derived by means of Fourier transforms from two-color photoelectric observations. The system shows a long term variation of its orbital period, which is interpreted as due to a continuing mass loss mechanism from the secondary component. Physical dimensions and a model of the system are also suggested here.