Patent ID: 8544979

Claim:
An ejection inspecting device, operable to inspect an ejection state of a fluid ejection device operable to eject a fluid, the ejection inspecting device comprising: at least one pair of electrodes, disposed so that the fluid can pass; a Colpitts oscillation circuit, connected to the electrodes, and operable to electrically oscillate; a counter, operable to count a counted number of peaks of oscillations oscillated by the Colpitts oscillation circuit during a predetermined period; an oscillation detecting unit, operable to detect an oscillation state from the counted number of oscillations; and a control unit, operable to detect whether the fluid has been ejected from the fluid ejection device based on a first number of oscillations, counted during the predetermined period, during which the fluid has not been ejected, and a second number of oscillations, counted during the predetermined period, during which the fluid has been ejected and has passed near the electrodes, wherein the Colpitts oscillation circuit includes a coil connected in parallel to the electrodes, and a capacitor connected to an end of the coil, and the electrodes and the coil are set not to be in a resonant state.