Method and apparatus for electrophotographic developing

Abstract

Abstract PURPOSE: To obtain images of superior distinctness and free from ground fog by letting the composite developer containing composite components chargeable to different polarities contact an electrostatic latent image holding medium and applying low frequency alternating electric fields. CONSTITUTION: Two sleeves 36A, 36B being non-magnetic hollow cylinders oppose to a drum-form electrostatic latent image holding medium 21. The sleeves 36A, 36B revolve at the speeds slightly differing from that of the drum 21. There are stationary magnetic means 37A, 37B on the middle side of the sleeves and their respective magnetization poles differ. There are magnetizing poles N 2 , S 2 , N 3 at an equal spacing in the first magnetic means 37A and N 3 pole is disposed near the drum 21. There are 4 poles in the lower magnetic means 37B, the N 1 pole and S 1 pole performing scooping up and conveying of the developer and the S 3 , S 4 poles being spaced at the spacing of a specified angle θ on one side of the drum 21. If, for example, the AC voltage of about 1KHz at effective value 200V is applied to the sleeves, the images of superior distinctness and less ground fog may be obtained owing to the action of the N 3 pole and S 3 , S 4 poles of different polarities. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Masaharu Okubo
• 👤 Yujiro Ando

Bibliographic Details