Abstract
Reversal development in electrophotography usually requires an external biasing source, especially in the case of continuous tone reproduction. It is further desirable to controll the value of the biase voltage following the surface potentiai, attenuation of the latent image. Such control is quite difficult in liquid development because the dark attenuation of the image potential, during development is rapid and complicated.
This paper deals with a method which requires no external biasing source but, instead, utilizes a latent image bearingsheet which has a uniformly charged frame zone outside the image area. In this method the bias voltage generating from the charge on the sheet, attenuates strictly in the identical manner with the image potential and this can form an excellent quality continuous tone image with low background.
As another modification, a uniformly charged sensitive sheet was used instead of development electrode, giving a similar result.
