Patent ID: 8567903

Claim:
A liquid droplet jetting apparatus which jets droplets of two types of liquids different in electric conductivity, the apparatus comprising: a liquid droplet jetting head which jets the droplets of the two types of liquids, respectively; a discharge mechanism which discharges the two types of liquids from the liquid droplet jetting head, respectively; a waste liquid recovery device which recovers the two types of liquids discharged by the discharge mechanism, the waste liquid recovery device including: a waste liquid case, an absorbing body accommodated in the waste liquid case, two liquid intake portions through which the two types of liquids discharged by the discharge mechanism flow respectively into the waste liquid case, and a waste liquid detection section which measures an electric conductivity in the absorbing body at a detection position away from the two liquid intake portions by predetermined distances respectively, and which distinctively detects whether only one of the two types of liquids arrives at the detection position or both of the two types of liquids arrive at the detection position; and a full liquid judging section which judges that the absorbing body is in a full liquid state under a condition that the waste liquid detection section detects that both of the two types of liquids arrive at the detection position in the absorbing body, wherein the two types of liquids are a first liquid, and a second liquid lower in electric conductivity than the first liquid; and the waste liquid detection section judges that the first liquid arrives at the detection position under a condition that the electric conductivity at the detection position in the absorbing body is higher than or equal to a first threshold value, judges that the second liquid arrives at the detection position under a condition that the electric conductivity at the detection position in the absorbing body is lower than or equal to a second threshold value lower than the first threshold value but is higher than or equal to a third threshold value lower than the second threshold value, and judges that both of the two types of liquids arrive at the detection position under a condition that the electric conductivity at the detection position in the absorbing body is lower than the first threshold value but higher than the second threshold value.