Printhead having low pressure rise nozzles
View Patent ↗A printhead is provided having a plurality of chambers on a substrate which each have a nozzle, a heater arranged in each chamber so as to heat fluid within the chamber to form a gas bubble therein and thereby cause ejection of a drop from the corresponding nozzle, and a plurality of passages formed in the substrate so that each passage supplies the fluid to an associated one of the chambers. Each chamber is configured so that the transient rise in pressure therein when the gas bubble is formed is less than 20 MPa.
1. A printhead comprising:
a plurality of chambers on a substrate, each chamber having a nozzle;
a heater arranged in each chamber so as to heat fluid within the chamber to form a gas bubble therein and thereby cause ejection of a drop from the corresponding nozzle; and
a plurality of passages formed in the substrate so that each passage supplies the fluid to an associated one of the chambers,
wherein each chamber is configured so that the transient rise in pressure therein when the gas bubble is formed is less than 20 MPa.
2. A printhead according to claim 1 wherein each chamber is configured so that the transient rise in pressure is less than 10 MPa.
3. A printhead according to claim 1 wherein each chamber is configured so that the transient rise in pressure is less than 5 MPa.
4. A printhead according to claim 1 wherein each heater is configured so that the gas bubble is formed at each of two opposing sides of the heater.
5. A printhead according to claim 1 wherein a multilayered structure of a plurality of the heaters is disposed within each chamber, each heater being formed in a different layer.
6. A printhead according to claim 1 wherein the areal density of the nozzles relative to the substrate exceeds 10,000 nozzles per square centimeter of the substrate.
7. A printhead according to claim 1 wherein the fluid supplied to each chamber is selected from the group consisting of: inks containing colored dyes; fixatives; infra-red absorber inks; functionalized chemicals; adhesives; biological fluids; water; and solvents.