Patent ID: 8079657
Filing Date: 2011-12-20
Classification: B41J,G01F

Abstract:
1. A liquid sensing device for use in a liquid consuming system in which air is introduced from an upstream end of the system in association with consumption of liquid at an downstream end of the system, the liquid sensing device comprising: a sensor positioning member that defines a sensing flow channel including an inlet hole at an upstream end of the sensing flow channel and a first outlet hole at a downstream end of the sensing flow channel; a sensor positioned on an outside face of the sensor positioning member at a location facing the sensing flow channel to sense whether liquid is present in the sensing flow channel; a sensor positioning member mounting portion that mounts the sensor positioning member, wherein the sensor positioning member mounting portion includes: a downstream buffer chamber-defining portion that includes an aperture communicating with the first outlet hole and that in conjunction with the sensor positioning member defines a downstream buffer chamber adapted to receive the liquid and the air exiting from the first outlet hole; and a second outlet hole communicating with the downstream buffer chamber and through which the liquid and the air from the downstream buffer chamber exit, and wherein contours of the downstream buffer chamber are defined such that the liquid and the air introduced from the first outlet hole flow to the second outlet hole in nonlinear fashion along a wall face of the downstream buffer chamber, wherein the sensor includes a piezoelectric element and is adapted to use the piezoelectric element to oscillate the sensor positioning member and sense whether the liquid is present; the sensor positioning member mounting portion further includes: an upstream buffer chamber-defining portion that includes an aperture communicating with the inlet hole and that in conjunction with the sensor positioning member defines an upstream buffer chamber adapted to supply the liquid to the inlet hole; and a dividing wall that divides the downstream buffer chamber from the upstream buffer chamber, and wherein the sensor positioning member and the sensor positioning member mounting portion do not contact one another in sections other than the dividing wall.