Patent attributes
The invention relates to a liquid sensor which can certainly judge the existence of liquid, and a liquid container including the sensor. The liquid sensor has: a vibration cavity forming base portion 40 having a first surface and a second surface opposite to each other, in which a cavity 43 for receiving liquid as a detection object is opened at a side of the first surface, and a bottom of the cavity 43 is capable of vibrating; and a piezoelectric element including a first electrode 46 formed at a side of the second surface of the vibration cavity forming base portion, a piezoelectric layer 47 laminated on the first electrode, and a second electrode 49 laminated on the piezoelectric layer. A shape of the cavity 43 in a plan view has a longitudinal dimension and a lateral dimension smaller than the longitudinal dimension.
