US 3,946,401 A · Electrothermographic image producing techniques

Abstract

A method of producing viewable images is disclosed wherein a layer of electrostatic charge is deposited on the surface of a 3d metal oxide that is disposed in an ambient temperature below the Neel temperature. The temperature at certain portions of the surface of the 3d metal oxide is increased to exceed the Neel temperature such that the 3d metal oxide undergoes an insulator-to-metal transition whereby the layer of electrostatic charge is selectively dissipated to form an electrostatic latent image corresponding to those portions of the surface that are subjected to an increase in temperature. The electrostatic latent image is then developed to form a viewable image. In one embodiment of the present invention the temperature is increased to exceed the Neel temperature by imaging a character pattern comprised of modulated radiant energy onto the surface of the 3d metal oxide. In another embodiment of this invention the temperature is increased to exceed the Neel temperature by transferring thermal energy forming a character pattern to the surface of the 3d metal oxide. In a further embodiment of this invention the electrostatic latent image is formed by depositing an electrostatic charge on the surface of the 3d metal oxide, the latter having certain portions thereof at a temperature that exceeds the Neel temperature therefor.

Claims13

Dependent claims

A method of producing viewable images on a surface comprised of an oxide of a 3d transition metal, comprising the steps of:

establishing an ambient temperature of said surface below the insulator-to-metal transition temperature of said 3d transition metal oxide such that said 3d transition metal oxide exhibits low electrical conductivity;
depositing a uniform layer of electrostatic charge on said surface;
selectively increasing the temperature of certain portions of said surface above said insulator-to-metal transition temperature in accordance with a determined pattern such that said certain portions exhibit high electrical conductivity whereby said uniform layer of electrostatic charge is selectively dissipated to form an electrostatic latent image of said determined pattern;
and
developing said electrostatic latent image to form a viewable image of said determined pattern.

2 more elements

Dependencies are inferred from the claim text.

Electrothermographic image producing techniques

Life of this patent

Electrothermographic image producing techniques

Life of this patent

Abstract

Claims13