| 摘要 |
PURPOSE:To improve durability and to obtain an excellent image of a high density without having fogging by using a developer contg. a carrier consisting of specific magnetic material particles and a toner as well as fine inorg. particles which are electrostatically charged positive by friction with the carrier. CONSTITUTION:The negative electrostatic latent image formed on the surface of a photosensitive body consisting of an org. photoconductive semiconductor is developed by a contact type magnetic brush developing method using the electrostatic image developer constituted by incorporating the carrier consisting of the magnetic material particles contg. copper, zinc and iron as essential components, the toner contg. styrene/ acryl copolymer and the fine inorg. particles which are electrostatically charged positive by friction with the above-mentioned carrier into the developer. The positive triboelectrostatic charge of an adequate electrostatic charge quantity is surely imparted to the toner by the synergistic effect of the carrier, the toner and the positive- chargeable fine inorg. particles contained in the above-mentioned developer; in addition, the good triboelectrostatic chargeability is not affected by environmental conditions such as high humidity. The good image of the high density having no fogging is thereby stably obtd. even after repetitions of many times without being affected by environmental conditions. |
