Serial ink jet printing head

摘要

The head is provided for a conducting ink and comprises a closed container (14) carrying two electrodes and a nozzle (18). The head is removably mounted on a carriage (13) and is replaced when the ink is exhausted. The container (14) is divided into two cavities (71 and 72) which are in communication by way of an aperture (73, 74, 75) in order to cause ink to flow to the nozzle and to remove bubbles. To ensure that the bubbles do not cause an increase in the pressure in the container, causing the ink to discharge from the nozzle, the container comprises an expansible cavity formed by a bag-type diaphragm (83) and a compression spring (82) which tends to cause expansion of the cavity. The container is filled with ink, while holding the spring in a compressed condition. As the ink decreases, the spring expands, maintaining a slight depression within the container.