Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1999-10-27
2001-02-20
Le, N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06190002
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to ink jet printers and in particular to an improved ink jet pen having a printhead surface adaptable for cleaning and to methods for making ink jet pens.
BACKGROUND OF THE INVENTION
During the lifespan of an ink jet pen containing one or more printheads, ink mist, dried ink and debris from the print media tend to accumulate on the nozzle plates of the printheads adjacent orifice holes therein. If not removed, the debris may accumulate to the point it blocks or partially blocks ejection of ink from the nozzle holes. Periodically, therefor, it is necessary to remove the debris from adjacent the nozzle holes so that the performance of the pen will not be impaired. Cleaning of the nozzle plates may be conducted using solvents or preferably by passing a flexible wiper across the nozzle plate to loosen and remove ink mist, dried ink and debris such as paper fibers therefrom. A wide variety of wipers and wiper blade designs are used for cleaning ink jet printhead nozzle plates.
In order to effectively clean a nozzle plate of a printhead with a wiper device, the pen must have a structure or configuration which lends itself to effective wiping across the nozzle plate or plates of the printheads. A single color ink jet pen contains a single printhead and a flexible circuit connected to a silicon substrate containing heater resistors and control devices for selectively ejecting ink from one or more nozzle holes of the printhead. Typically, the flexible circuit surrounds the nozzle plate or is integrally formed with the nozzle plate and is attached to a printhead carrier structure or pen body in a recessed portion therein. The raised sides of the pen body are often sufficient to protect the wiper from the relatively sharp edges of the flexible circuit as the wiper traverses the nozzle plate during a cleaning operation.
As contrasted with a single color ink jet pen, a multi-color pen contains multiple nozzle plates and associated flexible circuits for the printheads thereof. Typically, only the raised portions of the pen body adjacent the outermost edges of the flexible circuits protect the wiper as the blade of the wiper traverses the nozzle plates. It is difficult to adequately protect the wiper from interior edge portions of the flexible circuits remote from the raised portions of the pen body between adjacent nozzle plates because of printhead spacing tolerances. Thus these interior portions of the flexible circuits are often exposed. During a cleaning operation, as the flexible wiper blade traverses across the printhead surface of the pen body, the exposed edges of the flexible circuits can damage and/or cause excessive wear on the wiper.
SUMMARY OF THE INVENTION
With regard to the foregoing, the invention provides an improved ink jet pen for an ink jet printer. The ink jet pen includes a pen body having raised end walls, a recessed substantially planar portion between the end walls containing two or more printheads and flexible circuits therefor, each flexible circuit having at least one exposed edge. The flexible circuits are attached to the pen body in the recessed portion between the raised end walls and a polymeric thermoplastic material is disposed between adjacent flexible circuits in the recessed portion. The polymeric material has a height sufficient to protect a wiper from damage from the exposed edges of the flexible circuits between adjacent printheads during a printhead cleaning operation.
In another aspect the invention provides a method for protecting a wiper of a printhead cleaning station of an ink jet printer from damage from edges of a flexible circuit attached to an ink jet pen body during a printhead cleaning operation. The method includes providing a pen body having raised end walls and a recessed substantially planar portion between the end walls. A thermoplastic adhesive film is applied to the planar portion of the pen body and one or more printheads and one or more flexible circuits therefor are attached to the adhesive film in the recessed portion of the pen body. The one or more flexible circuits have first and second edges. Once attached to the adhesive film, the flexible circuits and film are heated under pressure to a temperature sufficient to cause the adhesive film to flow and encapsulate at least one of the first or second edges of the flexible circuits. The flowed adhesive film is then cooled in the encapsulated state to harden the flowed film and provide the first and second edges in a protected state sufficient to protect the wiper from damage from exposed edges of the flexible circuit during a printhead cleaning operation.
In yet another aspect the invention provides an ink jet printer having a printer housing and a printhead cleaning station and including an ink jet pen and ink cartridge containing ink attached to the pen. The pen contains a pen body having raised end walls, a recessed substantially planar portion between the end walls and two or more printheads and flexible circuits therefor, each flexible circuit having at least one exposed edge. The flexible circuits are attached to the pen body in the recessed portion between the raised end walls. A thermoplastic polymeric material is disposed between adjacent flexible circuits in the recessed portion and has a height sufficient to protect a wiper from damage caused by exposed edges of the flexible circuits during a printhead cleaning operation.
An advantage of the devices and methods of the invention is that the edges of flexible circuits attached to a multi-color ink jet pen body are protected so as to reduce damage and/or excessive wear to the flexible wiper blade and/or flexible circuit during printhead cleaning operations. Another advantage is that the polymeric material effectively encapsulates the edges of the flexible circuits thereby improving the ink resistance of the flexible circuits. Still another advantage is that the devices and methods enable cost effective manufacturing techniques and eliminate the need for applying individual encapsulant materials to the edges of the flexible circuit.
For the purposes of this invention the terminology “exposed edges” means those edges of the flexible circuits which if left unencapsulated provide relative sharp edges which could contact and cause damage or excessive wear to a wiper blade during a printhead cleaning. For the most part, exposed edges include the edges of the flexible circuits between adjacent printheads. The edges of the flexible circuits adjacent the sides of the pen body are somewhat protected by raised end walls on the pen body as described in more detail below and thus may be exposed, partially exposed or unexposed depending on the height of the end walls and the proximity of the edges to end walls.
REFERENCES:
patent: 4578686 (1986-03-01), Vollert
patent: 5148194 (1992-09-01), Asai et al.
patent: 5333007 (1994-07-01), Kneezel et al.
patent: 5388326 (1995-02-01), Beeson et al.
patent: 5530463 (1996-06-01), Nystrom et al.
patent: 5537133 (1996-07-01), Marler et al.
patent: 5576750 (1996-11-01), Brandon et al.
patent: 5644347 (1997-07-01), Schwiebert
patent: 5670997 (1997-09-01), Sugimoto et al.
patent: 5706038 (1998-01-01), Jackson et al.
patent: 5736998 (1998-04-01), Caren et al.
patent: 5751323 (1998-05-01), Swanson
patent: 5774140 (1998-06-01), English
patent: 5781209 (1998-07-01), Yoshimura
patent: 5786830 (1998-07-01), Su et al.
patent: 5815177 (1998-09-01), Sasaki
patent: 5831660 (1998-11-01), Kubo et al.
patent: 5870116 (1999-02-01), Kyoshima
patent: 5896143 (1999-04-01), Matsui et al.
patent: 0644051 A1 (1994-08-01), None
patent: 03227646 (1991-10-01), None
patent: 405201014 (1993-08-01), None
Le N.
Lexmark International Inc.
Luedeka Neely & Graham
Nghiem Michael
Sanderson Michael T.
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