| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of waste toner even when a cleaning device turns downward, and to make toner high in developing efficiency. SOLUTION: The toner has at least a binding resin and a colorant, is set so that weight average particle size is 5 to 12μm and has particles whose circularity (a) obtained from an expression (1) 'circularity (a)=L<SB>0</SB>/L' is≥0.900 by≥90% as the cumulative value of number reference in the particles whose particle size is≥3μm. In the toner, relation between the cumulative value Y of the number reference of the particles whose circularity (a) is≥0.950 and the weight average diameter X of the toner satisfies an expression (2) 'the number reference value Y of the particles whose circularity is≥0.950≥exp5.51×X<SP>-0.645</SP>'. COPYRIGHT: (C)2003,JPO |
