Patent ID: 7971956

Claim:
A liquid container comprising: a liquid containing portion for containing liquid; and a detection portion which outputs a detection signal having a frequency f1 of about f1=f2/B, where B is any odd number and where f2 is a frequency of a detection signal output when the amount of liquid contained in the liquid containing portion is equal to or less than a predetermined amount, when the amount of liquid contained in the liquid containing portion is greater than the predetermined amount, wherein the frequency f1 of the detection signal output when the amount of liquid contained in the liquid containing portion is greater than the predetermined amount and the frequency f2 of the detection signal output when the amount of liquid contained in the liquid containing portion is equal to or less than the predetermined amount satisfy Equation A: 0.75 *f 2(1−0.25 /B )/ B≦f 1≦1.25 *f 2(1−0.25 /B )/ B Equation A (where 0.25/B is a waveform margin and B is an odd number of 3 or less).