Image forming method and apparatus using a particular toner
US5774771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Feb 9, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09716
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming method has a developing step of developing an electrostatic latent image by the use of a developer to form a toner image on an electrostatic latent image bearing member, a primary transfer step of transferring the toner image onto an intermediate transfer member to which a voltage is applied, and a secondary transfer step of transferring onto a transfer medium the toner image held on the intermediate transfer member, while a transfer means to which a voltage is applied is pressed against the transfer medium. The developer has a toner. The toner is a black toner having at least i) black toner particles formed of a binder resin with a colorant dispersed therein and ii) an inorganic fine powder. The black toner has the value of shape factor SF-1 of 110<SF-1.ltoreq.180, the value of shape factor SF-2 of 110<SF-2.ltoreq.140, and the value of ratio B/A of 1.0 or less which is the ratio of a value B obtained by subtracting 100 from the value of SF-2 to a value A obtained by subtracting 100 from the value of SF-1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.