| 摘要 |
PURPOSE:To apply uniform pressure under any conditions and to obtain high picture quality by keeping pressure balance pressurizing members and making the pressure close to nearly 0 at the contact point between the members which come into contact and applying a required pressure again. CONSTITUTION:A developing roller 40 is supported by bearings 45 and 46 fitted in a frame wherein a shaft 41 slides in a certain direction and comes into contact with a photosensitive drum 10 almost in a linear contact state. Assuming that total pressure at the contact point become 2kg at the left half and 1kg at the right half when, for example, 4kg for pressure P1 and 3kg for pressure P2 are applied by springs 80 and 81, 2kg for pressure P3 and 1kg for pressure P4 are applied in the opposite directions by springs 84 and 85 to nearly eliminate the pressure at the contact point; and thus the right and left pressure balance is kept, and necessary pressure P5 and pressure P6 are applied again by nearly equal quantities by springs 82 and 83. Consequently, uniform pressurization is performed even with weak pressure to actualize uniform electrostatic charging, uniform development, and uniform transfer for high picture quality. |
