Inkjet printhead and printhead nozzle arrangement
View Patent ↗A printhead for an inkjet printer comprises a wafer assembly defining a plurality of spaced apart groups of ink supply channels and a plurality of groups of ink ejection nozzle arrangements. Each ink ejection nozzle arrangement comprises a nozzle chamber structure mounted to the wafer assembly. Each ink ejection nozzle arrangement further comprises an anchor extending from the wafer assembly in a location external to the nozzle chamber; and an elongate thermal actuator mechanism extending from the anchor and into the nozzle chamber. The thermal actuator mechanism comprises an elongate arm which terminates in a free end within the nozzle chamber, and a pair of layers of conductive material located on either side of the elongate arm. One of the layers is connected to a current supply for causing a differential thermal expansion in the elongate thermal actuator mechanism. A pit is defined adjacent each nozzle chamber structure for catching ink. The ink ejection nozzle arrangements of each group are arranged in a pair of rows, with the elongate thermal actuator mechanism of ink ejection nozzle arrangements of a first row extending away from those of ink ejection nozzle arrangements of a second row.
1. A printhead for an inkjet printer, the printhead comprising:
a wafer assembly defining a plurality of spaced apart groups of ink supply channels and a plurality of groups of ink ejection nozzle arrangements in fluid communication with respective ink supply channel groups, each ink ejection nozzle arrangement comprising:
a nozzle chamber structure mounted to the wafer assembly, and defining a nozzle chamber for receiving ink from an ink supply channel and an ink ejection port through which ink in the nozzle chamber is ejected;
an anchor extending from the wafer assembly in a location external to the nozzle chamber; and
an elongate thermal actuator mechanism extending from the anchor and into the nozzle chamber, the thermal actuator mechanism comprising an elongate arm which terminates in a free end within the nozzle chamber and a pair of layers of conductive material located on either side of the elongate arm, one of the layers being connected to a current supply for causing a differential thermal expansion in the elongate thermal actuator mechanism so that the free end of the arm is moved to eject ink in the nozzle chamber through the ink ejection port;
wherein
a pit is defined adjacent each nozzle chamber structure for catching ink and thereby impeding spilt ink from spreading across the printhead, and
the ink ejection nozzle arrangements of each group are arranged in a pair of rows, with the elongate thermal actuator mechanism of ink ejection nozzle arrangements of a first row extending away from the elongate thermal actuator mechanism of ink ejection nozzle arrangements of a second row.
2. A printhead as claimed in claim 1 , wherein the elongate thermal actuator mechanisms extend outwardly on either side of the nozzle chamber structures, and the nozzle chamber structures are centrally located.
3. A printhead as claimed in claim 1 , wherein each row comprises a plurality of linearly arranged sets of nozzle arrangements with adjacent sets being staggered relative to each other along the row.
4. A printhead as claimed in claim 1 , wherein the layers of conductive material are located proximal to the anchor.
5. A printhead as claimed in claim 3 , wherein the sets form a plurality of ascending or descending steps.
6. A printhead as claimed in claim 4 , wherein the layers of conductive material abut the anchor.