PURPOSE: To obtain excellent developed images through one-component magnetic brush development without any fog, by applying an electric bias for producing an alternating electric field to a development part together with a magnetic bias.
CONSTITUTION: An Se photoreceptor 1 rotates at a speed of 180mm/sec. A cylindrical sleeve 2 having a 30mm external diameter rotates at a 100r.p.m. rotational frequency, and a magnetic roll 3 having respective magnetic poles magnetized to 900 gauss and rotates at 1,000r.p.m. Magnetic flux density should be ≥500gauss, and 1,500gauss is preferred. This magnetic bias is so set that when development is carried out without application of an alternating electric field by a power source 10, toner is prevented from sticking a non-image part aside from the image quality of an image part. Insulating magnetic toner is conveyed on the sleeve and at a development, a 100HzW10kHz AC voltage is applied from the power source 10 to perform the development.
ITAYA MASAHIKO
TOMONO MAKOTO
