Toner for developing electrostatic image, image forming method and developing apparatus unit
US5948582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1998 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Mar 31, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/08782
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A toner for developing an electrostatic image is constituted by at least toner particles and an additive. The toner particles have a shape factor SF-1 of 100-160, a phase factor SF-2 of 100-140 and a weight-average particle size of 4-10 .mu.m as measured by a Coulter counter. The toner contains particles having circle-equivalent diameters in a range of 0.6-2.0 .mu.m and satisfying the following conditions (i)-(iii): (i) a first value C.sub.1 of 3-50% by number as measured by a flow particle image analyzer after application of a ultrasonic wave of 20 kHz for 5 min., (ii) a second value C.sub.2 of 2-40% by number as measured by the flow particle image analyzer after application of a ultrasonic wave of 20 kHz for 1 min., and (iii) a value C of 105-150 obtained according to the following equation: C=(C.sub.1 /C.sub.2).times.100 The toner is effective in improving image-forming characteristics in a continuous image formation on a large number of sheets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.