Printer with low voltage vapor bubble generating heaters

• US 7,543,916 B2
• Filed: 08/16/2007
• Issued: 06/09/2009
• Est. Priority Date: 11/23/2002
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Stephens; Juanita D
• Application Number:
  US11/839,539
• Publication Number:
  US 20070273729A1
• Time in Patent Office: 663 Days
• Field of Search: 347/12, 347/13, 347/20, 347/40, 347/42, 347/44, 347/47, 347/54, 347 56- 59, 347 61- 65, 347/67
• US Class Current: 347/57
• CPC Class Codes: B41J 2/04518 reducing costs
• CPC Class Codes: B41J 2/0452 reducing demand in current or voltage
• CPC Class Codes: B41J 2/04555 detecting current
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/0458 controlling heads based on heating elements forming bubbles
• CPC Class Codes: B41J 2/04588 using a specific waveform
• CPC Class Codes: B41J 2/1404 Geometrical characteristics
• CPC Class Codes: B41J 2/14072 Electrical connections, e.g. details on electrodes, connecting the chip to the outside...
• CPC Class Codes: B41J 2/1408 Structure dealing with thermal variations, e.g. cooling device, thermal coefficients of materials
• CPC Class Codes: B41J 2/1412 Shape
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/155 for line printing
• CPC Class Codes: B41J 2/1601 Production of bubble jet print heads B41J2/1606, B41J2/162 take precedence
• CPC Class Codes: B41J 2/1603 of the front shooter type
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 : thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1646 : thin film formation by sputtering
• CPC Class Codes: B41J 2002/14475 : characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2002/14491 : Electrical connection
• CPC Class Codes: B41J 2202/11 : characterised by specific geometrical characteristics
• CPC Class Codes: B41J 2202/19 : Assembling head units
• CPC Class Codes: B41J 2202/20 : Modules
• CPC Class Codes: B41J 2202/21 : Line printing

Abstract

An inkjet printer that has a printhead with a plurality of nozzles and one or more heater elements 10 corresponding to each nozzle, configured to operate at low voltage and low current. Each heater element 10 vaporises a printing fluid 11 to form a bubble 12 therein. The generation of the bubble 12 causes the ejection of a drop of the printing fluid (such as ink) through the corresponding nozzle 5 to effect printing. Each heater element 10 requires less than 8 volts and a current of less than 60 milliamps for less than 1.5 microseconds, in order to form the gas bubble 12 that causes the ejection of the drop of printing fluid 11. These lower voltages are more suited to CMOS circuitry components and helps to avoid problems such as ‘ground bounce’.

Claims

1. An inkjet printer for ejecting a printing fluid onto a media substrate, the inkjet printer comprising:

an array of nozzles,

a heater element corresponding to each of the nozzles respectively, such that,

the heater element vaporizes some of the printing fluid to generate a bubble that ejects a drop of the printing fluid through the nozzle;

wherein,

the heater element uses less than 8 volts at a current of less than 60 milliamps for less than 1.5 microseconds, to form the bubble that ejects the drop.

2. An inkjet printer according to claim 1 wherein the heater element uses less than 5 volts at a current of less than 20 milliamps for less than 1.5 micro-seconds to eject the drop.

3. An inkjet printer according to claim 1 wherein the heater element uses less than 3.5 volts at a current of less than 20 milliamps for less than 1.5 microsecond, to eject the drop.

4. An inkjet printer according to claim 1 wherein the heater element uses less than 3 volts at a current of less than 17 milliamps for less than 1.5 microseconds to eject the drop.

5. An inkjet printer according to claim 1 wherein the array extends the width of the media substrate to be a page-width printhead.

6. An inkjet printer according to claim 1 wherein each heater element is in the form of a cantilever beam.

7. An inkjet printer according to claim 1 wherein each of the nozzles defines an ejection aperture positioned less than 50 microns from the heater element.

8. An inkjet printer according to claim 1 configured to receive a supply of the printing fluid at an ambient temperature, wherein each heater element is configured such that the energy required to be applied thereto to heat said part to cause the ejection of a said drop is less than the energy required to heat a volume of said ejectable liquid equal to the volume of the said drop, from a temperature equal to said ambient temperature to said boiling point.

9. An inkjet printer according to claim 1 wherein the array of nozzle is fabricated on a substrate having a substrate surface, the areal density of the nozzles relative to the substrate surface exceeding 10,000 nozzles per square cm of substrate surface.

10. An inkjet printer according to claim 1 wherein each heater element has two opposite sides and is configured such that a said vapour bubble formed by that heater element is formed at both of said sides of that heater element.

11. An inkjet printer according to claim 1 wherein the vapour bubble formed by the heater element is collapsible and has a point of collapse, and wherein each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element.

12. An inkjet printer according to claim 1 wherein the heater element has a generally planar structure that is formed by chemical vapor deposition (CVD).

13. An inkjet printer according to claim 1 further comprising a wafer substrate supporting the nozzle and the heater element, the nozzle being formed in a nozzle plate, the nozzle plate being parallel to and spaced less than 10 microns from the wafer substrate.

14. An inkjet printer according to claim 1 further comprising a plurality of nozzle chambers each corresponding to a respective nozzle, and a plurality of said heater elements being disposed within each chamber, the heater elements within each chamber being formed on different respective layers to one another.

15. An inkjet printer according to claim 1 wherein each heater element is formed of solid material more than 90% of which, by atomic proportion, is constituted by at least one periodic element having an atomic number below 50.

16. An inkjet printer according to claim 1 wherein each heater element includes solid material and is configured for a mass of less than 10 nanograms of the solid material of that heater element to be heated to a temperature above said boiling point thereby to heat the printing fluid to a temperature above said boiling point to generate the bubble.

17. An inkjet printer according to claim 1 wherein each heater element is substantially covered by a conformal protective coating, the coating of each heater element having been applied substantially to all sides of the heater element simultaneously such that the coating is seamless.