Ink jet recording apparatus having residual quantity detection unit and residual quantity detection method therefor

摘要

According to the present invention, there is provided an ink jet recording apparatus for recording an image on a recording medium by discharging ink to the surface of the recording medium, wherein ink is reserved in an ink tank including a negative pressure generating member, such as an absorber and a foaming member, and a function of accurately detecting the residual quantity such that depletion to a predetermined level can be detected is realized. Light emitted by a photointerrupter is allowed to pass through a portion of a wall surface of the ink tank made of transparent plastic or the like which is transmissible with respect to detection light emitted by the photointerrupter to detect change in the light reflectance in the boundary portion between the wall surface and the ink absorber. In accordance with reflectance obtained in a case where no ink exists in the detected portion and that obtained in a case where ink exists, the residual quantity of ink can be detected.