Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1999-04-30
2001-09-25
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S086000
Reexamination Certificate
active
06293649
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to inkjet printers. It relates more particularly to the mounting and electrical connection of thermal inkjet print cartridges in the printer.
BACKGROUND OF THE INVENTION
Inkjet printers, and thermal inkjet printers in particular, have come into widespread use in businesses and homes because of their low cost, high print quality, and color printing capability. The operation of such printers is relatively straightforward. In this regard, drops of a colored ink are emitted onto the print media during a printing operation, in response to commands electronically transmitted to the printhead. These drops of ink combine on the print media to form the text and images. Inkjet printers may use a number of different ink colors. One or more printheads may be contained in a print cartridge, which may either contain the supply of ink for each printhead or be connected to an ink supply located off-cartridge. An inkjet printer frequently can accommodate two to four print cartridges. The cartridges typically are mounted side by side in a chute attached to a carriage which sweeps the cartridges back and forth within the printer during printing.
While inkjet printers have achieved a high level of reliability, there are times when the cartridges containing the printhead must be accessed by the owner or user of the printer. If the cartridge contains the ink supply for the printhead, it must be removed for replacement or refill when the supply runs out. Even if the ink supply is off-cartridge, the printheads may occasionally clog and need manual cleaning.
Print cartridges have typically required access from a top portion of the printer. In some printers, most if not all inkjet cartridges are positioned within the printer at some distance from any one of the wall members, thus making access from a wall side of the printer impractical. Even if the back and forth movement of the cartridges during printing brings them near to a side of the printer, access to all but the cartridge nearmost the side wall member is not feasible. In other inkjet printers, a latching lever which holds the print cartridge in place must be flipped up from the top to remove the cartridges. In yet other inkjet printers, keying features which ensure that different color cartridges are installed in the correct chute stalls require a substantially vertical insertion of the cartridge during installation. The need for top access increases as the height of the print cartridge approaches the height of the printer, as can occur when cartridges become taller to hold more ink, or printer heights are reduced to conserve space.
While access to install and remove cartridges from a top portion of the printer has been generally satisfactory for most office and home environments, with the introduction of internet appliances such access is not generally satisfactory. More particularly, internet appliances such as cable boxes, DVD players, and other such electronic components must generally be stackable. Thus, it would be impractical to position a top access printer in such a stacked arrangement.
Accordingly, it would be highly desirable to have a new and improved inkjet printer that could be stacked with other electronic devices and that would provide access to replace depleted inkjet cartridges in an easy and convenient manner.
SUMMARY OF THE INVENTION
In a preferred embodiment, the present invention may be implemented as a print cartridge latching mechanism for a displaceable chute that allows print cartridges to be accessed through a side of the printer rather than through the top of the printer. A printer constructed in accordance with the present invention can be stacked with other equipment and still provide access to the print cartridges without the need to remove equipment on top of the printer.
Such a printer has a chute with walls defining one or more receiving spaces or stalls into which print cartridges may be installed. The chute is attached to a carriage which moves the cartridges along an axis and relative to the print media during a printing operation. The chute and carriage are connected by a mechanism which allows the chute to be located in a proper position for printing on the media, and in a different position for servicing the print cartridges, such as installing or removing them. A latching mechanism on the chute engages the carriage to hold the chute in the printing position, and disengages from the carriage to allow the chute to move to the service position. The latching mechanism has a shaft, a cam latch that engages the carriage, and a handle that opens and closes the latch and moves the chute. Preferably, the shaft also has a preload cam attached to it for each stall into which a cartridge may be installed.
Each print cartridge has a set of printhead electrical interconnects which receive signals that control the flow of ink; these interconnects mate with a set of controller interconnects mounted on the carriage that are attached to the drive electronics which signal the printhead to emit ink. A first opening in the chute where the printhead electrical interconnects are located allows the two sets of interconnects to be maintained in electrical contact during printing by a biasing force applied by the preload cam. The preload cam applies this force by contacting the print cartridge at a position spaced apart from the first opening at the opposite end of the stall.
In operation, the latching mechanism engages the carriage before the preload cams start exerting biasing force on the cartridges. The latching mechanism is rotatable until just past the point of maximum biasing force, where a stop or the geometry of the cam latch prevents further motion. A guide arrangement in the receiving space cooperates with datums on the print cartridge to direct the cartridge into proper mechanical and electrical alignment when the biasing force is applied.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
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patent: 5408746 (1995-04-01), Thoman et al.
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patent: 5646665 (1997-07-01), Swanson et al.
patent: 5712669 (1998-01-01), Swanson et al.
patent: 5870125 (1999-02-01), Swanson et al.
patent: 6065831 (2000-05-01), Kawaura et al.
Barlow John
Hewlett--Packard Company
Sismilich Robert C.
Stewart Jr. Charles W.
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