Method of priming picolitre inkjet printhead
View Patent ↗A method of priming an inkjet printhead having ink ejection nozzles. The method includes: providing an ink bag containing ink for distribution to the nozzles via a fluid path between the ink bag and the nozzles; applying inwardly directed force on at least one exterior wall of the ink bag so as to reduce an available fluid volume of the ink bag, thereby causing ink to flow from the ink bag to the nozzles along the fluid path; and arranging a biasing member in the ink bag so that the biasing member applies outwardly directed force on at least one interior wall of the ink bag to restrain the reduction of available fluid volume of the ink bag only once the available fluid volume has been reduced to a predetermined volume. Each nozzle is configured to eject an ink drop having a volume of about 1.2 picolitres.
1. A method of priming an inkjet printhead, the inkjet printhead having a plurality of ink ejection nozzles, the method comprising the steps of:
providing an ink bag containing ink for distribution to the nozzles via a fluid path between the ink bag and the nozzles;
applying inwardly directed force on at least one exterior wall of the ink bag so as to reduce an available fluid volume of the ink bag, thereby causing ink to flow from the ink bag to the nozzles along the fluid path; and
arranging a biasing member in the ink bag so that the biasing member applies outwardly directed force on at least one interior wall of the ink bag so as to restrain the reduction of available fluid volume of the ink bag only once the available fluid volume of the ink bag has been reduced to a predetermined volume,
wherein each nozzle of the printhead is configured to eject an ink drop having a volume of about 1.2 picolitres.
2. A method according to claim 1 , wherein the biasing member incorporates a leaf spring.
3. A method according to claim 2 , wherein the leaf spring is made from a material having shape-memory characteristic.
4. A method according to claim 3 , wherein the material is Mylar.
5. A method according to claim 2 , wherein the leaf spring is formed by folding an elongate arcuate piece of the material about an approximate centre line orthogonal to the longitudinal extent thereof so that the leaf spring exhibits an outwardly directed spring restoring force.
6. A method according to claim 5 , wherein the leaf spring is formed so as to have a folded longitudinal length and radius of curvature which result in the leaf spring being able to float within the ink contained in the ink bag prior to the application of the inwardly directed force by the force applicator.
7. A method according to claim 1 , wherein the ink bag is configured to have an available fluid volume of at least 19 millilitres.
8. A method according to claim 7 , wherein the predetermined available fluid volume is at least 15 millilitres.
9. A method according to claim 7 , wherein the ink bag is configured to have an available fluid volume of at least 23 millilitres.
10. A method according to claim 1 , wherein the nozzles of the printhead are arranged so as to print at a resolution of 1600 dots per inch.
11. A method according to claim 1 , wherein the ink bag contains one of magenta ink, cyan ink and yellow ink.