The invented non-clogging cap and service station include a cap that encloses and defines a cavity around a printhead. The cap includes a basin to collect liquid discharged from the printhead and a vent to prevent changes of pressure within the cavity. Capillary spaces are constructed within the cap from walls and ridges in such a way that liquid collecting in the basin moves away from the vent to prevent the vent from clogging. The basin, vent, walls and ridges are typically constructed from a wetting material to facilitate capillary action. An ink drain pan may also be included to receive liquid that overflows the basin. In this manner, the invention provides a vented cap to protect the printhead and uses capillary action to prevent the vent from clogging and causing the cap to malfunction. Furthermore, a wiper may be mounted near the cap to clean the printhead. The cap and wiper together form the invented service station.
A capillary vent system for a service station cap system in an ink-jet printer having a basin formed on a substantially planar surface mounted on the under side of a nylon sled subjacent a cap for a printhead mounted on the top surface of the sled which serves as a cover for the basin. A vent is defined between a semicircular groove formed on the under side of the basin cover such that the vent is in fluid communication with the basin and has a lower surface substantially coplanar with the underside of the cover. The vent extends from the edge of the cover to a location over the basin. Ink from the printhead collects in the basin and at least some of the collected ink drains through the vent. The vent forms a capillary space between the basin member and the basin cover to draw the collected ink in, thus preventing vent clogging.
In order to clean a dirty printhead, the dirty printhead is first capped and the ink pressure in the printhead increased significantly to allow ink to escape through the orifices and completely fill a small gap inside the cap portion. After letting the orifices soak for a predetermined time to dissolve the dried ink and loosen dust debris which may be found on the printheads, the cap drainhole is opened to drain the ink while keeping the ink pressure inside the head at an intermediate higher level. Dirty ink remaining inside the orifice bore is removed using a self cleaning wiping station in separate steps. During a first step, the wiping element is pressed into contact with the orifices. The dirty ink, because of the high pressure inside the printhead, is unable to reenter the printhead and is absorbed by the wiping element. In a second step, the pressure inside the printhead is decreased significantly below operating pressures to enable the menisci to retreat inside an orifice lip. Then the orifices are again wiped with another portion of the wiping element to remove any remaining ink and to assist in drying the printhead. Once the printhead has been cleaned, the wiping station is moved out of engagement with the printhead and the wiping station automatically cleans the wiping element by passing the wiping element through the washing fluid and the squeegee element until absorbed ink is removed from the wiping element.
An automatic system for cleaning a thermal inkjet printhead. A thermal inkjet cartridge and service station are provided within a printer unit. The service station is directly beneath the cartridge when it is not printing. Attached to the service station is a printhead wiper unit consisting of a single member or, in the alternative, dual members positioned against each other to form a capillary pathway therebetween. The cartridge includes a compartment having an opening therethrough and an absorbent member impregnated with cleaning solution When the cartridge is not printing, the wiper unit is aligned with the compartment containing the absorbent member and is in contact therewith. This supplies the wiper unit with cleaning solution The service station may include a secondary absorbent member contacting with the wiper unit to absorb cleaning solution from the capillary pathway in a dual wiper system or supply the pathway with additional solution
A cap member is for covering, during suction operations, nozzle rows formed in a single nozzle plate of an ink jet head on an ink jet printer. The cap member includes a surrounding lip, a partitioning lip, and a body. The surrounding lip is for forming a sealed condition around the nozzle rows when in intimate contact with the nozzle plate during suction operations. The partitioning lip is for forming, with the outer lip portion, partitioned spaces that separate the nozzle rows from each other. The body is formed from resin and includes an integral base portion and protruding portion. The base portion is formed with a separate suction hole for each partitioned space. The protruding portion protrudes away from the base portion. At least one of the surrounding lip and the partitioning lip cover the protruding portion.
A rounded capillary vent system for ink-jet printers in which an ethylene propylene diene monomer (EPDM) element having a basin formed on a substantially planar surface is mounted on the under side of a nylon sled. An EPDM cap for a printhead is mounted on the top surface of the sled. A vent is defined between a semicircular groove formed on the under side of the nylon cover and the EPDM planar surface. The vent extends from the edge of the cover to a location over the basin. Ink from the printhead collects in the basin and at least some of the collected ink drains through the vent. Ink in the vent collects in the corners formed at the juncture of the EPDM material and polycarbonate cover. The capillary space between the EPDM material and the nylon cover draws the collected ink thereinto thus preventing vent clogging.
