| 摘要 |
PURPOSE:To detect a toner density accurately, by providing through hole having a small diameter in the bottom cover of a vessel for storage of a developer of a toner density detecting reactor and measuring the reactance variance while generating a gentle stream of the developer. CONSTITUTION:A funnel-shaped vessel 4 which constitutes a part of a toner density detecting reactor 1 and consists of nonmagnetic materials is formed with an aperture part 4', a cylindrical part 4'', and a bottom cover 6. The cylindrical part 4'' is provided with an iron core 12 which is formed with laminated iron materials or the like into a channel shape, and a coil 10 is wound around the cylindrical part 4''. The bottom cover 6 is provided with a through hole 8 having a small diameter and is opened and closed with a shaft 14 as a fulcrum. In case that the toner density of a developer is detected, the bottom cover 6 is closed, and a developer 2 is filled in the vessel 4 while flowing out the developer from the through hole, and an AC current is supplied to the coil 10. The degree of closeness in the vessel 4 becomes high by flowing-out of the developer 2 from the through hole 8, and the variance of the inductance of the coil 10 for the variance of the toner density is enlarged, thus improving the detection precision. |
