Patent ID: 7137679
Filing Date: 2006-11-21
Classification: B41J

Abstract:
1. 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 element of said piezo-electric device has a vibration part, and said piezo-electric device outputs a signal indicating a residual vibration state of said vibration part under free vibration, wherein said vibration part of said piezo-electric element 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 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 measures a periodic peak value of a waveform of counter electromotive force generated by residual vibration remaining in said vibration part by a predetermined number of said periodic peak values from a predetermined point of time, and said piezo-electric device measures more number of said periodic peak values than said predetermined number of said periodic peak values in subsequent detection of said ink consumption condition, and thereby detects said ink consumption condition.