Patent ID: 7971945

Claim:
An ink consumption condition detection method for detecting an ink consumption condition in an ink container loaded in an ink jet recording apparatus having a recording head for jetting ink drops, wherein said ink consumption condition in said ink container is detected using a piezo-electric device having a piezo-electric element during a non-recording state of said recording head, wherein said piezo-electric device further has a vibrating plate on one side of which said piezoelectric element is arranged, and a cavity forming member having a cavity which is arranged on the other side of said vibrating plate, wherein said piezo-electric device has a vibration part, and said piezo-electric device outputs a signal indicating a residual vibrating state of said vibration part under free vibration, wherein said vibration part contacts with an ink in said ink container via said cavity, said cavity defining an area of said vibration part, wherein said ink consumption condition is detected after a voltage has been applied to the piezo-electric element based on a change of said residual vibrating state of said vibration part under free vibration corresponding to ink being consumed, and wherein said piezo-electric device is attached to a distal end of a module body which is mounted on said ink container so as to pass through a side wall of said ink container, the distal end of the module body being inserted into an inside of said ink container.