A new technique for the transfer of electrostatic images (TESI) is described.
The TESI method provides unique applications, for example, to electrostatic printer free from drum cleaning and to thermoplastic recorder. In the conventional TESI method, the recording medium consists of a dielectric layer and a conductive layer (10⁹—10¹²Ω surface resistivity). The latter serves to supress the abnormal air breakdown which deteriorates the quality of the recorded pictures.
However, it is possible to transfer latent images to dierectric films without the conductive layer. In this new technique, AC corona neutralizes the biasing charge immediately after the image transfer. By this neutralization, the biasing charge density of the film becomes equal to the transfered image charge density, so as to enable a very stable transfer.
The experimental and theoretical investigations of the new TESI method and practical considerations for stabler transfer are described.

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Magnetic brush development of electrostatic images was studied under a variety of condition of magnetic flux density, quantity of brush spike, contact angle of brush spike, brush revolving speed, bias potential and toner consumption.
The dispersion of carrier iron powder from developing device is reversely proportional to magnetic flux density of developing brush.
To obtain good quality of electrophotographic print, the relation between the brush spike quantity, distance from the magnet to the electrophotographic paper and distance from the magnet to the doctor, is very important.
The toner consumption in magnetic brush development depends upon the kind of original and becomes much as the original has many solid area or continuous-tone.

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