Patent ID: 8688013
Filing Date: 2014-04-01
Classification: G03G

Abstract:
1. A developing device comprising: a first developer conveyance path and a second developer conveyance path for conveying and circulating a two-component developer including a toner and a magnetic carrier; a first communicating path for guiding the two-component developer in the first developer conveyance path to the second developer conveyance path; a second communicating path for guiding the two-component developer in the second developer conveyance path to the first developer conveyance path; a first conveyance member being provided in the first developer conveyance path in a freely rotatable manner for conveying the two-component developer in one direction; a second conveyance member being provided in the second developer conveyance path in a freely rotatable manner for conveying the two-component developer in one direction; a developing roller for bearing and supplying the two-component developer in the first developer conveyance path to a photoconductor drum; a developer collection path for guiding the two-component developer left on a surface of the developing roller after the developer is supplied to the photoconductor drum and used for the development in a direction away from the first developer conveyance path; a third developer conveyance path for containing the two-component developer guided to the developer collection path and conveying the developer in one direction; a third conveyance member being provided in the third developer conveyance path in a freely rotatable manner; a toner supply port for supplying new toner to the third developer conveyance path; a developer drawing and conveyance path for guiding the two-component developer supplied with the new toner in the third developer conveyance path to the second developer conveyance path; and a developer drawing member being provided in the developer drawing and conveyance path in a freely rotatable manner for simultaneously agitating and conveying the two-component developer in one direction, wherein the first developer conveyance path is disposed above the second developer conveyance path in the vertical direction, wherein the third developer conveyance path is disposed under the second developer conveyance path in the vertical direction, and wherein the developer drawing and conveyance path is elongated in the vertical direction into a cylindrical shape and includes a first opening at a lower end thereof in the vertical direction for taking in the two-component developer from the third developer conveyance path and a second opening at an upper end thereof in the vertical direction for sending, to the second developer conveyance path, the two-component developer conveyed upward in the vertical direction by the developer drawing member.