FIELD OF THE INVENTION
This invention relates to printers which are capable of utilizing
multiple types of media and, more particularly, to a method and apparatus for enabling
automatic identification of a media type upon a mounting thereof on a printer.
BACKGROUND OF THE ART
Currently, many printers, plotters, etc. are able to utilize various
types of media during their respective print actions. Each media type generally
requires a resetting of printer parameters in order to optimize print quality.
Such media types include special papers, e.g., matte paper, glossy papers, semi-glossy
papers, etc. and various non-paper-based media such as vellum, film, etc. Printer
parameter modifications vary with the type of media, and can include changes in
color maps and print modes.
Presently, the user must use a display panel on the printer (or a
dialog box in the printer driver that is resident on the host computer) to select
the type of media that is being loaded into the printer. This action involves
the user scrolling through a list of displayed media types, until one appears which
matches the media type to be loaded on the. printer. Thereafter, the user selects
that media type and the printer controller automatically establishes printer parameters
in accordance with the selection.
The above-indicated procedure requires that the user knowswhat media
type is to be (or has been) loaded on the printer. The media type is generally
written on the media box but, as is known, many users do not read either the box
or the instructions which accompany the media. Further, once the box is thrown
away, the media type data is lost and if the user then re-installs the media on
another printer, the user is required to either remember or guess the media type.
If a wrong media type is selected, unacceptable print quality can result. As the
user is not aware that it is the incorrect media type which has been entered,
the blame for the poor print quality is placed upon the printer (and the printer
manufacturer), resulting in significant levels of customer dissatisfaction. The
problem of multiple media types is especially severe in plotters which employ a
multiplicity of media types, depending upon the particular application.
As printers are now marketed on a world-wide basis (along with their
respective media), manufacturers generally include multiple foreign language versions
of instructions for display on the printer's display panel. If the foreign language
instructions are not ready at the time the printer is shipped into a foreign market,
the display will be particularly confusing to the user -assuming that the user
is unable to understand the instructions which appear on the printer's display.
As more media types are developed, user confusion will increase unless steps are
taken to automatically identify the media type, upon installation of the media
onto the printer.
The prior art has suggested the printing of data on sheets of media
to enable the loading of printer parameters directly from media sheets. Other prior
art has suggested that special inks be employed which are invisible to the user,
but which can be sensed by special optical sensors to enable a loading of parameters
into a printer. Still other prior art has suggested the use of printed data on
media sheets, which printed data, when subjected to a heating step thereafter becomes
invisible. Still other prior art has embedded a memory chip in the end of a media
roll, with sense apparatus being utilized to read settings from the chip, as the
roll is employed.
Each of the above prior art implementations requires the use of either
a special ink, a special sensor, or other apparatus which adds to the cost of media
Accordingly, it is an object of this invention to provide an improved
method and apparatus for enabling a printer to automatically identify a media type
It is another object of this invention to provide an improved method
and apparatus for enabling identification of a media type (and other data regarding
the media) to a device which employs media wound on rolls.
It is yet a further object of this invention to provide a method
and apparatus for identifying a media type that is mounted on a printer, wherein
media identification data does not appear on printed media output by the printer.
JP-A-05 301 673 discloses a roll like printed medium discriminating
mechanism for a printer with an optical reader (bar code reader 20) fitted to a
printed medium such as a label continuous body 6 and capable of reading an identification
code indicating the type of the printed medium 6, printed medium type data input
mechanism (printed content input mechanism 24) for inputting the type data of the
printed medium 6, and a discriminating circuit 21 for discriminating the compatibility
of the printed medium 6 charged to charging mechanism (a label continuous body
feed shaft 7) by comparing the read identification code with the type data.
US-A-4,721,058 discloses an automated drawing system having an automatic
drawing machine which receives input data from a central control unit for making
a drawing on a roll of drawing paper in accordance with the input data. At the
time of making the drawing, the automatic drawing machine also encodes the drawing
paper with a bar code pattern representative of the lengthwise and widthwise size
of the drawing. The drawing paper is then advanced to a paper cutter system which
includes a bar code reader for reading and decoding the bar code pattern and for
producing therefrom control signals indicative of the desired lengthwise and widthwise
size of the drawing. These control signals are fed to a Y-axis or widthwise cutter
and an X-axis or lengthwise cutter which accordingly cut the drawing paper in lengthwise
and widthwise directions to obtain a cut piece of drawing paper containing thereon
the drawing and having a size determined by the bar code pattern.
DE-A-4,240,135 discloses a digital computer having a length cutter
to cut paper. The length cutter is only activated after a signal is received from
a control unit, to thereby ensure that length cutting takes place only after cross-section
or width cutting of the paper. Light barriers connected to the control unit detect
the start and end of the paper.
SUMMARY OF THE INVENTION
The invention includes a method and apparatus for identifying a media
type to be printed upon and communicating the identification to a printer. The
method includes the steps of: reading data from the media to at least identify
the media type; storing the data and employing information from the data to establish
printer control parameters; removing the leading portion of the media which contains
the data (if the data was printed on the leading edge of the media) and thereafter
printing on the media, as required. Upon occurrence of a later event, data identifying
the media is reprinted on a leading edge of the media, which data is derived from
data that was stored when the data from the media was initially read. The data
printed on the leading edge, in addition to identifying the media type, preferably
indicates a remaining length of media available for printing.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic frontal view of a printer employing roll media,
which printer is adapted to perform the invention hereof.
Fig. 2 is a perspective view of a roll of media, showing a positioning
of data which identifies, at least, the media type.
Fig. 3 is a perspective view of a printhead and media cutter employed
on the printer of Fig. 1.
Fig. 4 is a schematic end view of the structure shown in Fig. 3
DETAILED DESCRIPTION OF THE INVENTION
Hereafter, the invention will be described in the context of an inkjet
plotter/printer which utilizes a roll of media. It is, however, to be understood
that the invention is equally applicable to other types of printers that either
employ roll media, folded media or, in certain cases, individual media sheets.
Referring to Fig. 1, printer 10 includes an ink jet printhead 12
which translates along a pair of slider bars 14 and 16 across the width of media
18. In the known manner, a controller 20, by control signals sent to inkjet printhead
12 causes printhead 12 to traverse along slider bars 14 and 16 and to eject ink
droplets onto media 18 which passes therebeneath. Media 18 passes over a roll
21 which positions media 18 accurately beneath printhead 12 for printing. Media
18 also passes over a cutter bar 22 which, in cooperation with a cutter 24 (similar
to a pizza cutter), enables a transverse cut to be made across media 18.
Cutter 24 is mounted on a carrier 26 which is also mounted for sliding
movement along slider bars 14 and 16. When printhead 12 is moved into contact with
carrier 26, a coupling mechanism 28 enables carrier 26 to move along with printhead
12 and to cut off a section of media 18.
Referring to Fig. 2, a roll 30 of media 18 is shown, before mounting
on printer 10. In a first embodiment, the leading edge of media 18 includes coded
indicia 32 identifies at least, the media type and, preferably, further identifies
the size of the media and its remaining length. Coded indicia 32 is initially printed
on the leading edge of media 18 when the media is produced at the factory. It
may be configured in the form of a bar code or any other indicia which is readable
by an optical sensor 34 (see Fig. 1). In a second embodiment, coded indicia 33
may be printed on an end of roll 30 (or applied via a label) where it can be read
by a further optical sensor 35 (Fig. 1).
Sensor 34 is positioned to read coded indicia 32 as it passes thereover.
Data read from the coded indicia is fed to controller 20 which stores the data
in a memory 38. Controller 20 then utilizes the data derived from the indicia
to set parameters for control of printer 10 (i.e., in accordance with the media
type identified by the coded indicia).
Controller 20 further causes roller 21 to move media 18 a short distance
so that coded indicia 32 passes cutter bar 22. Printhead 12 is then moved to engage
carrier 26. Thereafter, printhead 12 drags carrier 26 and cutter 24 across media
18, cutting off the portion of media 18 which carries coded indicia 32. Normal
printing/plotting then can occur. If the system also employs coded indicia 33
and sensor 35, there is no requirement that the media be initially imprinted with
coded indicia 32, thus avoiding the cutting action when a brand new roll is mounted.
However, thereafter, as will be understood, the first and second embodiments operate
in the same manner.
Referring to Fig. 3, a perspective view illustrates the action of
inkjet printhead 12, carrier 26 and cutter 24 as a portion of media 18 is being
cut which contains the coded indicia. Fig. 4 illustrates a schematic end view
of the structure of Fig. 3, as the cutting action takes place.
Once the section of media 18 which contains coded indicia 32 has
been removed, printer 10 is ready to print or plot a print job. When the printing
of a sheet is finished, the cutting action, above described, again takes place
to enable the printed sheet to be removed from the roll of media 18.
At such time a new coded indicia 32 may be printed on a leading edge
of media 18 by printhead 12, or such printing action can be inhibited until requested
by the user. The reason for this additional print action is to emplace coded indicia
on the media so that the user can change media roll 30 between plots or print jobs.
The printer/plotter on the which roll 30 is newly mounted is then able to read
the coded indicia and to establish appropriate control parameters. In any event,
if both sensors sense coded indicia, the coded indicia on the leading edge of
the media governs.
If coded indicia 32 is printed on media 18 after each print job,
the disadvantage is that a portion of media 18 which includes coded indicia 32
is cut off before starting each print/plot action. The preferred technique, which
is entirely unobtrusive until the user wishes to change the roll of media, is to
enable the user to select an "unload" command which enables controller 20 to cause
printhead 12 to print coded indicia 30 on the end of media 18. Coded indicia 32,
in addition to identifying the media type, also identifies the remaining length
of media 18. Such data enables a next printer/plotter on which media roll 30 is
mounted to determine the both the available media length and to select proper
print control parameters for the media.
It should be understood that the foregoing description is only illustrative
of the invention. Various alternatives and modifications can be devised by those
skilled in the art without departing from the invention as claimed in the appended