Incremental printing of symbolic information – Ink jet – Controller
Reexamination Certificate
2002-02-21
2003-09-30
Hallacher, Craig (Department: 2853)
Incremental printing of symbolic information
Ink jet
Controller
C347S037000
Reexamination Certificate
active
06626511
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to automated hard copy apparatus, such as ink-jet printers, and more specifically to an adjustable carriage mount for aligning an automated writing instrument, such as an ink-jet printhead, with respect to a printing zone of the apparatus.
2. Description of Related Art
The art of ink-jet technology is relatively well developed. Commercial products such as computer printers, graphics plotters, copiers, and facsimile machines employ ink-jet technology for producing hard copy. The basics of this technology are disclosed, for example, in various articles in the
Hewlett
-
Packard Journal
, Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No.1 (February 1994) editions. Ink-jet devices are also described by W. J. Lloyd and H. T. Taub in
Output Hardcopy [sic] Devices,
chapter 13 (Ed. R. C. Durbeck and S. Sherr, Academic Press, San Diego, 1988).
FIG. 1
(PRIOR ART) depicts an ink-jet hard copy apparatus, in this exemplary embodiment a computer peripheral printer,
101
. A housing
103
encloses the electrical and mechanical operating mechanisms of the printer
101
. Operation is administrated by an electronic controller
102
(usually a microprocessor or application specific integrated circuit (“ASIC”) controlled printed circuit board) connected by appropriate cabling to a computer (not shown). It is well known to program and execute imaging, printing, print media handling, control functions and logic with firmware or software instructions for conventional or general purpose microprocessors or with ASIC's. Cut-sheet print media
105
, loaded by the end-user onto an input tray
120
, is fed by a suitable paper-path transport mechanism (not shown) to an internal printing zone
107
where graphical images or alphanumeric text is created. A carriage
109
, mounted on a carriage rod, or slider,
111
, scans the print zone
107
. An encoder subsystem
113
,
201
is provided for keeping track of the position of the carriage
109
at any given time. A set of individual ink-jet pens, or print cartridges,
115
x
are releasably mounted in the carriage
109
and fluidically coupled, such as by flexible tubing
119
, to ink reservoirs
117
x
(generally, in a full color system, inks for the subtractive primary colors, cyan, yellow, magenta (CYM) and true black (K) are provided; an ink fixer chemical (F) is also sometimes provided). Once a print job is completed, the print medium is ejected onto an output tray
121
. The carriage scanning axis is conventionally designated the x-axis, the print media transit axis is designated the y-axis, and the printhead firing direction is designated the z-axis. [or convenience of describing the ink-jet technology and the present invention, all types of print media are referred to simply as “paper,” all compositons of colorants are referred to simply as “ink,” and all types of hard copy apparatus are referred to simply as a “printer.” No limitation on the scope of invention is intended nor should any be implied.]
In essence, the ink-jet printing process involves digitized dot-matrix manipulation of drops of ink ejected from a pen onto an adjacent paper. One or more ink-jet type writing instruments (also referred to in the art as an “ink-jet pen” or “print cartridge”) includes a printhead which generally consists of drop generator mechanisms and a number of y-axis aligned columns of ink drop firing nozzles of a substantially planar nozzle plate superjacent the drop generator mechanisms. Each column or selected subset of nozzles (referred to in the art as a “primitive”) selectively fees ink droplets (typically each being only a few picoliters in liquid volume) that are used to create a predetermined print matrix of dots on the adjacently positioned paper as the pen is scanned across the media. A given nozzle of the printhead is used to address a given matrix column print position on the paper (referred to as a picture element, or “pixel”). Horizontal positions, matrix pixel rows, on the paper are addressed by repeatedly firing a given nozzle at matrix row print positions as the pen is scanned. Thus, a single sweep scan of the pen across the paper can print a swath of tens of thousands of dots. The paper is stepped to permit a series of contiguous swaths. Complex digital dot matrix manipulation is used to form alphanumeric characters, graphical images, and photographic reproductions from the ink drops. Page-wide ink-jet printheads are also contemplated and are adaptable to the present invention. Thus, it can be recognized that a critical operating factor is printhead-to-paper spacing and alignment to ensure aerate dot placement.
FIG. 2
(Prior Art) schematically illustrates a typical pen-to-paper alignment scheme. The front of the carriage
109
(with respect to the leading edge of a sheet of paper
105
in the print zone
107
supported by a platen or suspended by a paper pivot apparatus (neither shown)) is used as a pivot point “A” and known manner camming mechanisms (not shown) are provided on at least one end of the slider
111
. Note that mechanical tolerances inherent in such rod adjustment mechanisms can be the source of vibration of the rod and hence the carriage and pens. Letting “Theta-X” represent the pitch angle of the printhead
201
with respect to a Y-plane, it can be recognized that Theta-X is not held when adjusting the slider up or down (as represented by the arrows Z-up and Z-down) with the carriage
109
pivoting about point “A.” Therefore, another adjustment mechanism would be required to ensure pitch axis parallelism between the printhead
201
and the paper
105
. It can also now be recognized that other degrees of freedom of the printhead
201
must be accounted for; let “Theta-Y” represent the roll angle of the printhead with respect to an X-plane, and let “Theta-Z” represent the yaw angle of the printhead nozzle columns with respect to the Y-axis. When both Theta-Z=0° and Theta-X=0°, the long axis—that is, the columns of nozzles—of the printhead
201
is parallel to the paper transport Y-axis; when Theta-Y=0°, the short axis of the printhead—that is, a line perpendicular to the columns of nozzles—is parallel to the carriage scanning X-axis.
There is a need for an adjustable carriage mount which will provide independent carriage alignment.
SUMMARY OF THE INVENTION
In its basic aspects, the present invention provides a system for aligning a writing instrument to a print medium, including: a support base having a substantially fixed position; a chassis for retaining the writing instrument; and a plurality of support mechanisms for coupling the chassis to the base, each of the support mechanisms having alignment mechanisms for independently adjusting spacing between the chassis and the base wherein pitch angle and roll angle of the writing instrument with respect to the print medium is determined by adjusting each of the support mechanisms.
In another basic aspect, the present invention provides an ink-jet hard copy apparatus, including: a base having a substantially fixed spatial orientation; a print zone having a substantially fixed spatial orientation with respect to the base; a chassis for retaining at least one ink-jet printhead device in a predetermined orientation the print zone; and a plurality of supports for coupling the chassis to the base, each of the supports being fixedly mounted to the base and each of the supports having a range of settable distance positions wherein setting the distance between the printhead device and the print zone simultaneously adjusts the printhead device pitch and roll angle with respect to the print zone.
In another basic aspect, the present invention provides a method for adjusting the spatial orientation of an ink-jet printhead to a printing zone of an ink-jet hard copy apparatus. The method includes the steps of: providing at least three independen
Hallacher Craig
Hewlett -Packard Development Company, L.P.
Huffman Julian D.
LandOfFree
Adjustable chassis for automated writing instrument carriage does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adjustable chassis for automated writing instrument carriage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adjustable chassis for automated writing instrument carriage will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3020444