Hideyuki Nakao

New ion-jet printing head controlled by a low-voltage signal

The ion-jet printing method controls the ion flow directly to make an electrostatic latent image on an insulated layer. This printing method has several advantages over laser printing, such as high printing speed and simple maintenance. However, conventional ion-jet method poses a problem, particularly for office printer applications, because a high- voltage circuit is required to control the ion flow. We developed the new ion-jet printing method to solve this problem. The new process uses a precharge to accelerate the ion flow to the insulated layer, and the high-voltage bias is eliminated from the head. So, the new ion-jet head permits controlling the ion flow by a low-voltage signal. Experimentally, we attained a printing speed of 20 ppm and a resolution of 400 dpi at the control voltage of -30 V, and succeeded in printing Chinese characters with 32 X 32 dots per 2 mm square.

Color Laser-Printer Using Roller-Transfer

A highly stable color laser printer has been experimentally developed, which uses a newly devised toner transfer roller, made of elastic sponge rubber sheathed with a plastic resistive layer. The developed color printer attains the following features: i. High quality full color images can be printed under broad operating conditions, e.g. from 20°C,40%RH to 30°C,85%RH. ii. Frequent color adjustment is not necessary because printed image color differences under different operating conditions are within 3. iii. The maintenance interval can be extended; the toner transfer efficiency from the photoconductor drum to the paper is above 85%. The amount of waste toner is reduced to about 1/3 of that for a conventional printer on an average.