| 摘要 |
PURPOSE:To detect clog of a nozzle of an ink jet printer by colliding an ink droplet to be injected from the nozzle to a vibration sensor and measuring the amplitude of a vibration at the time of collision. CONSTITUTION:A pulse generator 25 is operated to inject an ink droplet 31 from the end 26 of a nozzle toward paper 32. The injected droplet 31 is collided with the paper 32. A vibration sensor 28 detects a vibration when the droplet 31 is collided with the paper 32, and generates a voltage in response to the degree of the vibration. An amplifier 29 amplifies the voltage value of the sensor 28, and outputs it to a discriminator 31. A discriminator 30 judges a normal injection of the droplet 31 if the signal from the amplifier 29 exceeds a predetermined value, and judges clog of the nozzle if the amplified signal does not become a predetermined value. |
