| 摘要 |
1,130,452. Developing electrostatic images. RANK XEROX Ltd. Dec.9, 1965 [Dec.28, 1964], No. 52192/65. Heading G2H. A method of developing an electrostatic latent image by bringing the member carrying the image into contact with a fluid dispersion of toner particles is characterized by agitating a mixture of toner particles and carrier particles in a region adjacent the member while applying an electric field, distinct from the image field, to the mixture, thereby separating the toner particles from the carrier particles and causing movement of separated toner particles from the mixture towards the image bearing member. As shown, a grid 13, Fig. 3, is placed adjacent a xerographic plate 10. A conductive shoot 18 conveys and agitates developer 14 poured from a container 16. A potential 15, of the same polarity as the toner particles is applied to the shoot causing toner particles to be separated from carrier particles due to the field between the shoot 18 and screen 13; the separated toner particles form a cloud. Large carrier particles are prevented by screen 13 from entering the image field. By applying a bias to screen 13 e. g., 10 to 130 volts, back ground deposits of toner on the plate 10 are reduced. The toner particles may be dispersed in air, carbon dioxide, nitrogen, or hydrocarbons such as kerosene or trichloro trifluor and ethane. In a modification, Fig. 4 (not shown) a xerographic drum (21) rotates past charging, exposure, development, transfer and cleaning stations. At the development station developer (31) is cascaded above a shoot (32) adjacent a screen 33. |
