| 摘要 |
PURPOSE: To detect residual quantity of ink accurately by providing a coupler with a flexible sheet being bonded to the end of the side wall of an ink passing chamber thus closing the opening and disposing a photoreflector oppositely to the flexible sheet. CONSTITUTION: Rear surface of the second ink passing chamber 2b and the front surface of the first ink passing chamber of a coupler 2 are formed of a first flexible sheet 11. Ink enters between a protrusion 2k and the flexible sheet 11 so long as it is present in an ink bag 5 and the flexible sheet 11 looks black because of the ink color when it is viewed from the outside. Consequently, a photoreflector 12 detects a large difference between outgoing light and incoming light. When ink in the bag 5 runs out, ink between the protrusion 2k and the sheet 11 flows out into an ink channel 2c and the sheet 11 adheres to the protrusion 2k thus exhibiting white surface of the protrusion 2k. Consequently, the photoreflector 12 detects a small difference representative of running out of ink. |
