Mita Industrial Co., Ltd.

Akira Horiuchi

Masahiko Kubo

Masahiko Maeda

Toshikazu Matsui

Akira Fushida

Nobuyasu Honda

Masanori Fujii

Nobuyuki Tsuji

Yuuji Hasegawa

Kazunori Yukitake

Disclosed is a negatively chargeable blue toner comprising a fixing resin binder and an indanthrone dye as a coloring and charge controlling agent. The indanthrone dye as the coloring and charge controlling agent may be used advantageously not only singly but also in combination with a halogen-substituted copper phthalocyanine pigment.

Negatively chargeable blue toner comprising indanthrone dye

Disclosed is an electrophotographic process which comprises developing an electrophotographic light-sensitive layer having an electrostatic charge image of a certain polarity with a one-component type magnetic developer where positive and negative frictional charge polarities are mingled, under development bias voltage conditions capable of developing the electrostatic charge image, the background or both, and bringing the light-sensitive layer having a developer layer formed thereon into contact with a transfer sheet under a transfer charge of the same polarity as that of the electrostatic charge image when a positive image is formed or under a transfer charge of a polarity reverse to that of the electrostatic charge image when a negative image is formed, to form an image on the transfer sheet.

Method for forming negative and positive images in electrophotographic

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Shimamoto, Japan

Akira Horiuchi