An actuator is provided to generate an ultrafine stroke according to a fluid input pressure such as air pressure or the like. On this displayed graph 261, at a position of a parameter value corresponding to a determined photographic scene, an icon 262 of the photographic scene is displayed. A plurality of openings 45 are formed at one edge of the ink supply channel 41. The control circuit also comprises a variable gain block, which receives the feedback control signal and which is configured to modulate the main pole proportionally to a variable gain of the gain block. This is accomplished either by an offset configuration of non-concentric inner and outer tubes, where the inner tube is shifted laterally away from the hood, or by employing an enlarged hood. The structure satisfies a condition of nb\u2212na>0.