a nozzle is supplied with pressurized ink , and is given mechanical vibrations , thereby to generate large - diameter and small - diameter ink droplets successively and alternately from an ink column produced from the front end part of the nozzle . charging and deflecting electrodes are disposed which charge one of the large - diameter and small - diameter ink droplets developed from the foremost end of the ink column , in response to a recording signal and which exerts a deflecting force on the charged ink droplet simultaneously with the development of the large - diameter and small - diameter ink droplets . thus , the flight orbits of the charged ink droplets necessary for the recording of an ink - jet recording device and the ink droplets unnecessary for the recording can be separated immediately after the development of the ink droplets .