Abstract: An ink coagulating agent of metal salt is provided in a waste ink tank. The coagulating agent is dissolved in aqueous solvent to be a metal salt solution. Absorbers of a porous material are impregnated with the metal salt solution and disposed in the waste ink tank.

Abstract: With an ink jet recording head (8) comprising two common ink chambers (26) and (27) communicating with both sides of a pressure generation chamber (24) and ink supply ports (30) and (31) where ink flows into the common ink chambers (26) and (27) from the outside, one ink supply port (30) is connected to a subtank (10) and the other ink supply port (31) is connected to an ink cartridge (6). The subtank (10) is replenished with ink through the ink jet recording head (8). Since ink reversely flows into the ink cartridge (6) via the recording head (8) from the subtank (10) due to the head difference, ink in the recording head (8) can be forcibly circulated without complicating a flow passage configuration.

Abstract: Disclosed is an ink-jet type recording device that includes drive signal generation circuit 84 for generating a trapezoidal drive signal in synchronization with a timing signal applied from an external device, switching transistors respectively for outputting a drive signal to piezoelectric vibrators in accordance with a printing signal applied from an external device, and control signal generation means for generating a pulse signal to turn on the switching transistors so that only a portion of the drive signal is output to any piezoelectric vibrators set in a non-printing condition in synchronization with a timing signal. This portion of the drive signal is applied to the piezoelectric vibrators belonging to those nozzle openings that should not jet out ink droplets in accordance with the pulse signal, so that menisci in the nozzle openings are merely vibrated slightly, respectively.