| 摘要 |
PURPOSE:To detect the accurate amt. of contents without plunging a detecting end for the amt. of contents into a flexible vessel at any time by disposing a pressure sensitive element such as strain gage by brinding its pressure receiving surface in tight contact with the outer side surface of the vessel. CONSTITUTION:A developing device has a part 7 where a part of the bottom wall is made of a flexible material with respect to the hopper wall of a toner hopper 3 which is a toner containing vessel. A pressure sensitive element 8 such as strain gage is disposed by bringing its pressure receiving surface in tight contact with the hopper outer side surface of an extended film 7 which is a flexible material wall. Thus, the weight pressure of the toner in the hopper 3 acts effectively through the wall 7 upon the element 8. Therefore, the accurate current amt. of the contents is detected without plunging the detecting end for the amt. of contents into the vessel at any time. |
