Shutter ink jet

• US 6,485,123 B2
• Filed: 05/14/2001
• Issued: 11/26/2002
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/855,094
• Publication Number:
  US 20010045969A1
• Time in Patent Office: 561 Days
• Field of Search: 347/9-11, 347/20, 347/44, 347/47, 347/48, 347/54-57
• US Class Current: 347/11
• CPC Class Codes: B41J 11/0005 Curl smoothing, i.e. smoothing down corrugated printing material, e.g. by pressing means acting on wrinkled printing material
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• 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 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• 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 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 1/2112 : using still video cameras
• CPC Class Codes: H04N 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 : Still video cameras
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation
• CPC Class Codes: H04N 5/7458 : the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: Y10S 977/932 : for electronic or optoelectronic application

Abstract

An ink jet printer uses an actuator and an oscillating pressured ink supply. A shutter is located between the ink supply and an ink ejection port, normally blocking the ink ejection port. An actuator is provided for moving the shutter mechanism on demand away from the ink ejection port so as to allow for the ejection of ink on demand from the ink ejection port. The actuator includes a thermal actuator in a coiled form constructed primarily from polytetrafluorethylene. The coil is uncoiled upon heating. The actuator includes a serpentine heater element encased in a material having a high coefficient of thermal expansion. The serpentine heater takes a concertina form upon heating and a thick return trace returns the actuator to its original position upon cooling.

Claims

1. A method of operating an ink jet printhead that includes a plurality of nozzle arrangements, each nozzle arrangement defining a nozzle chamber and an ink ejection port in fluid communication with the nozzle chamber, and a closure that is operatively positioned wityh respect to the ink ejection port, the closure being displaceable between open and closed positions to open and close the ink ejection port, respectively, on receipt of an electrical signal, the nozzle chamber being in fluid communication with an ink reservoir, the method comprising the steps of:

maintaining each closure in the closed position;

subjecting ink in the ink reservoir and thus each nozzle chamber to an oscillating pressure, selectively and independently supplying each closure with an electrical signal to displace the closure into the open position so that an ink droplet is ejected from the ink ejection port as a result of the oscillating pressure.

2. The method of claim 1 which includes ejecting the ink droplet on a first cycle of positive pressure applied to the ink, so that the droplet separates on a first cycle of negative pressure applied to the ink.

3. The method of claim 2 which includes maintaining the closure in the open position during a second cycle of positive pressure to facilitate refilling of the nozzle chamber from the ink reservoir.

4. The method of claim 3 which includes closing the ink ejection port before a second cycle of negative pressure for inhibiting withdrawal of ink from the nozzle chamber.

5. An ink jet printhead chip which comprises a substrate,

a plurality of nozzle arrangements positioned on the substrate, each nozzle arrangement comprising

nozzle chamber walls and a roof wall that define a nozzle chamber and an ink ejection port defined in the roof wall in fluid communication with the nozzle chamber;

and

a closure that is operatively positioned with respect to the ink ejection port, the closure being displaceable between a closed position in which the closure closes the ink ejection port and an open position in which ink ejection port is open, on receipt of an electrical signal, an ink reservoir, the ink reservoir being in communication with each nozzle chamber; and

a pressure generating means associated with the reservoir for imparting an oscillating pressure to ink in the reservoir, so that, when the closure is displaced into the open position, drop of ink is ejected from the ink ejection port.

6. The printhead chip of claim 5 in which the closure includes a shutter that is mounted on an actuator in a normally closed position in alignment with the ink ejection port, activation of the actuator on receipt of said electrical signal causing the shutter to move out of alignment with the ink ejection port to open the ink ejection port.

7. The arrangement of claim 6 in which the actuator is an electro-thermal bend actuator.