Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
Field of the Invention
Thi~ invention relates generally to printing
systems, and more particularly to printing systems
for printing characters in variou~ ont~ and formats
onto webs of sh~et stock of variou~ wid~h~, or cutting
the web to various lengths to accommodate the various
formats and for automatically ~tacking the tags after
~hey are cuto
Description of the Prior Art
Printer~ capable of printing character~ in
variou~ font~ and forma s on~o web~ of various ~ize~
ar~ known. One ~uch printer i5 de cribed in United
States Patent application Serial No. 151,577 filed by
~rederick M. Pou on May 20, l9B0, now United States
Patent No. 4,372,696 granted February ~, 1983.
While prior art printers such as the one
described in the aforementioned United States
Patent No. 4, 372,696 do provide a way to
print characters of various fonts and formats onto
various size webs of shaet stock, such printers can
be augmented to incorporate additional features. The
prior art prlnters generally print the required infor-
mation onto th~ web in the de~ired forma~ and then
cut the web into tag~ of a predetermined length con-
talning one or more tag sections. For purposes of
discussion each section thus cut will be referred to
as a tag regardless of the number of tags actually
printed on the section. The individual ta~s printed
on each tag will be referred to as tag sections.
Moreover, since the printer according to the invention
is capable of printing onto various types of web stock
including, for example, stock that can be cut into
labels, cards or the like, the term tags is intended
to cover sections cut from various web stock, and is
not limited to merchandise tags.
In a typical printer, after the tags are
printed and cut, they exit the printer through a con-
duit such as a chute, and when a stacker is used, are
expelled onto a conveyor belt within the stacker.
Afterward the tags are removed from the stacker in
stacks. In such stackers, the tags may be stacked in
a shingle mode or in piles. However, the stacking
mode cannot be readily altered, and in the stacking
in piles mode, the spacing between the piles must be
great enough to accommodate the widest tags that are
printed. This results in a reduction in stacker capa-
city for narrow tags.
The tags are generally printed in batches
ranging from a few tags to hundreds of tags per batch.
Typically~ the tags in each batch are very similar in
size and shape, and differ from tags in other batches
only by an item of information, such as, for example,
a price or item code. Consequently, because of the
physical similarity of the tags of different batches,
it is difficult and time consuming for the operator
to separate the various batches of tags, and frequently
the operator is required to read a large number of
tags in order to make the separation.
In the prior art printers, when one or more
tags become lodged in the exit conduit or chute,
printing is terminated when the jam is detected.
Unfortunately, in many instances, the jam is not
detected until a large number of tags back up in the
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chute. ~owever, because the number of tags present
in the chute at the time the printing is terminated
is generally much larger than the number of tags in a
typical batch, tags from several batches become mixed
up in the chute. These tags must then be manually
resorted by the operator into their proper order in
the various batches before printing can be resumed.
This results in a considerable delay in the printing
process.
In the prior art printers the wrong size
web for a given format can be loaded into the printer
and result in the printing of wrong size tags for a
given format. When the web used is too wide for the
selected format, the result is that many tags may be
wasted before the error is detected. In the case
where the web is too narrow for the selected format,
damage to the printing head or other machine components
can occur. Such damage can be costly both in terms
of the actual cost of repair to the machine, and in
lost production while the machine is down.
In the prior art printers, the position at
which the various lines are printed on a tag varies
from printer to printer as a result of mechanical
tolerances. While in many instances, the variation
in line print position may not be objectionable, in
other instancesl it can be significant, particularly
when multiple printers are being operated simul-
taneously, and the tags from the Yarious printers can
be readily compared.
The stackers associated with the prior art
printers are generally able to stack in only a single
mode (either a shingle mode or a stack in piles mode),
even though, in many instances, it is desirable to
change the stacking mode of a stacker to accommodate
various tags or operating conditions.
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SUMMARY OF THE ~[NVENTION
~ccordingly, it is an object of the present
invention to provide an improved printer that overcomes
many of the disadvantages of the prior art printers.
It is yet another object of the present
invention to provide a printer-stacker combination
that offers greater flexibility of operation than
prior art printer-stacker combinations.
It is still another object of the present
invention to provide a printing system that facilitates
the separation of individual batches of items being
printed.
It is yet another object of the present
invention to provide a printing system that inserts
tags of different lengths between batches of tags to
facilitate separation of the batches,
It is yet another object of the present
invention to provide a printing system that permits
separation of the various printed tags into groups
and subgroups with the groups of tags being separated
by a tag of different length than the printed tags,
and the subgroups being separated by a tag of different
length than the tag separating the groups.
It is yet another object of the present
invention to provide a printer-stacker combination
that permits the stacking mode to be readily altered.
It is another object of the present invention
to provide a printing system that rapidly detects a
jam in the exit conduit or chute in order to maintain
sequence integrity of the output tags.
It is yet another object of the present
invention to provide a printer that prevents informa-
tion rom being printed on incorrect size stoc~.
It is yet another object of the present
inventiOn to provide a printing system that indicates
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to the operator the correct size stock required for a
particular printing operation.
It is yet another object of the present
invention to provide a printer that prints the correct
S or required size stock onto incorrect size stock when
incorrect size stock is used.
It is yet another object of the present
invention to provide a printer that checks the length
and width of the stock loaded therein and suspends
the printing operation if incorrect stoc~ is used.
It is yet another object of the present
invention to provide a stacker that provides for the
stacking of various width tags in piles at maximum
density along its conveyor belt by varying the spacing
between piles in accordance with th~ width of the
tags being printed.
It is yet another object of the present
invention to provide a stacker that will not stack
tags from more than one batch in a single pile.
It is still another object of the invention
to pro~ide a printer that electronicall~ adjusts print
line position to compensate for mechanical tolerances
of the printer.
Therefore, in accordance with a preferred
embodiment of the invention there is provided a printer
that inserts an extended length tag followed by a
reduced length tag between the various batches of
tags printed to facilitate the separation of the
batches. In addition, a second extended length tag,
which is longer than the extended length tag used
between batches, followed by a second reduced length
tag that is shorter than the reduced length tag uti-
lized between batches is inserted between ~roups of
batches to permit the batches to be separated into
groups of related batches. Also, space is provided
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at the top of the second extended length tags to permit
information identifying the group of batches immediately
following each second extended length tags to be printed
thereon by the printer. If desired, other extended
length tags that have lengths that are different than
the lengths of the above-mentioned extended length
and second extended length tags may be provided if
additional levels of separation are desired.
A sensor is provided within the exit conduit
or chute to sense the presence of a tag in the chute.
The aforementioned sensor cooperates with an event
counter to count the number of tags delivered to the
chute after the presence of a tag within the chute
has been sensed, and acts to terminate the printing
of additional tags after the count in the event counter
reaches a predetermined number, preferably two or
three. By thus limiting the number of tags that can
be present in the exit conduit or chute to a relatively
low number, the disruption of sequence integrity that
occurs when the chute is filled with a large number
of tags as a result of a blockage or jam in the chute
is avoided.
In order to avoid the problems that occur
when the wrong size web is placed in the printer,
information defining the lengths and widths of the
tags required for each format is stored in the machine~
Whenever a new format is selected, this information
is printed onto whatever web stock is in the machine
in a format small enough to fit on the smallest stock
that can be used with the machine. The information
is read by the operator who loads the required web
stock/ or iE the stock in the machine is the correct
stock, indicates to the machine by pushing a load or
a start button that the stock presently in the machine
is the correct stock. When the correct web is loaded,
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or the load or star~t button depressed, printing can
commence; however, as an added check, indices indica-
tive of tag length are disposed on the web at spaced
intervals, and the spacing between the indices is
compared with the stored value of tag length to deter-
mine whether the correct web has indeed been loaded.
If so, printing is permitted to continue, but if not,
the printing operation is terminated. This serves as
an additional check on the operator.
The stacker is controlled by the machine to
allow the tags to be stacked either in piles or in a
shingle mode under the control of the operator,
depending on which mode is desired. When the pile
~tacking mode is selected, the conveyor belt of the
stacker is maintained stationary until a predetermined
number of tags are stacked~ after which the conveyor
belt is incrementally advanced and the next pile is
stacked. The increment that the conveyor belt is
advanced is determined by the width of the tag being
printed in order to optimize the capacity of the
stacker. If the end of a batch is reached before a
full stack has been stacked, the conveyor belt is
advanced so that the new batch of tags is stacked on
a new pile in order to assure separation between
~5 batches.
Logic is provided to adjust the print posi-
tion of the various lines to compensate for mechanical
tolerances in the printer.
BRIEF_DESCRIPTION OF THE DRAWING
These and other objects and advantages of
the present invention will become readily apparent
upon consideration of the following detailed descrip-
tion and attached drawing wherein~
FIG. 1 is a partially simplified perspective
view of the stacker-printer according to the invention;
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FIG. 2 is a side sectional view of the stacker
taken along line 2-2 of FI~. l;
FIGS. 3 and 4 are sectional views of the
stacker taken along line 3-3 of FIG. 2 and showing
two different modes of operation of the stacker;
FIG. 5 is a top view of the stacker, partially
in cross section, taken along line 5-5 of FIG. 2;
FIG. 6 is an illustration of the various
tags that can be printed by the system according to
the invention;
FIG. 7 is a functional block diagram of the
control system employed in the printer stacker according
to the invention;
FIGS. 8-12 are functional flow charts illus-
trating the logical operation of the control circuitry
of the stacker-printer according to the invention;
FIG. 13 is a partial illustration of the
stacker showing the stack in piles mode of operation;
and
FIG. 14 is an illustration of two tags
showing the effects of the dynamic print line compen-
sation feature of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, with particular
attention to FIG. 1, the stacker~printer according to
the invention is generally designated by the re~erence
numeral 10 The stacker-printer 10 according to the
invention includes a stacker portion 12 and a printer
portion 14. The printer portion 14 is similar to the
printer illustrated in the aforesaid United States
Patent Application Serial No. 151,577, and for this
reason is lllustrated in simplified and diagrammatic
form. The function of the printer 14 is to pr~nt
alphanumeric characters onto a web of sheet stock 16
that is subsequently cut into a plurality of tags 18
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that are stacked by the stacker 12. The web 16 is
stored on a roll 20 and advanced through a printing
station (not shown in FIG. 1) by a pair of rollers 22
and 24, one or both of which may be driven by a paper
advance motor 26, which is preferably a stepping motor.
The printing on the sheet stock occurs at a
printing station which includes a print head 28, which
preferably includes a matrix type wire printer, but
may be a thermographic or any other suitable type of
print head. The print head is moved across the web
stock 16 in a direction transverse to the longitudinal
axis of the web 16 by a carriage driver motor 30 which
is also preferably a stepping motor. After being
printed, the web stock 16 is advanced to a cutting
station having a pair of cutter blades 32 and 34, one
or both of which may be driven by a cutter driver 36
which activates the cutter blades at predetermined
intervals to cut the web 16 into tags 18 of a length
determined by the format of the tag being printed.
After the web stock has been cut into the tags 18,
the tags exit through an exit chute or conduit 3
onto a conveyor belt 40 of the stacker 12.
In accordance with an important aspect of
the present invention, the length to which the tags
18 may be cut is variable, not only to accommodate
different formats, but also to provide a separation
between batches of tags, as well as groups of batches.
When tags are printed, the operator is given a written
order defining the tags to be printed. The order
typically has an order number or some other form of
identification associated with it that defines the
batches of tags to be printed. For example, an order
may state that a batch of 100 tags of a certain format
is required. Additional information for that batch
can include, for e~ample, price, an item code, and
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possibly a description of the item, such as, for
example, a size 12 red dress. The operator reads the
order and enters the pertinent information defining
the batch into the printer, and proceeds with the
printing.
Once printing is initiated, the operator
reads the information defining the next batch of tags,
which may be a 50 tag batch having a price for a size
8 blue dress. The operator proceeds to enter all of
the information defining each batch until the complete
order is entered. The operator then proceeds to the
next order and enters it in a similar manner. The
printer then prints the various batches of tags in
the same sequence in which they were entered, and
outputs the tags through the exit chute or conduit
38, and onto the conveyor belt 40. The conveyor belt
40 is driven by a motor 42 (FIG. 5), which may be any
suitable motor, but is preferably a stepping motor~
The conveyor belt 40 can be moved intermittently by
the motor 42 to stack the tags in piles (FIG. 13), or
moved continuously to stack the tags 18 in a shingle
fashion as illustrated in FIGS. 1 and 3. After the
tags are stacked, they are periodically removed from
the conveyor belt 40 by the operator and packed with
their respective orders.
In many instances, the tags of the various
batches are very similar to each other, particularly
batches from a single order. Thus, to facilitate the
separation of the batches, the device according to
the invention inserts a tag 17 that is longer than
the tags 18 comprising the batch after all the tags
18 comprising the batch have been printed. The long
tag 17 is followed by a short tag 17' (FIGS. l and 6)
that is shorter than the tags 18 comprising the batch.
Typically, the short tag 17' is shorter than the batch
~2~5~
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tags 18 by an amount equal to the amount that the
long tag is longer than the batch tags. Thus, if the
long tag 17 were, for examplej 1/8" longer than the
tags 18 comprising the batch, the short tag 17' would
be 1/8" shorter. The reason for this relates to the
use of tag length indicating indices 41 on the web
16, and prevents misregistration of subsequently
printed tags because the total length of the shorter
tag and the longer tag is equal to the length of two
normal batch tags. This relationship is best illus-
trated in FIG. 6 which shows the tags arranged with
the indices and a preprinted logo A CO. aligned in a
straight line relationship. Thus, it can readily be
observed that any length added above A CO. is subtracted
from the distance between the index 41 and the bottom
of a subsequently printed tag.
In addition to separating the various batches,
the operator must also separate the various orders.
Such separation is facilitated by the stacker-printer
according to the invention by inserting an extra long
tag 19 that is longer than the long tags 17 between
tags of different orders. The ex~ra long tag 19 is
likewise followed by an extra short tag 19' that is
shorter than the normal batch tag 18 by an amount
equal to the amount by which the extra long tag is
longer than the normal batch tags. Thus, for example,
if the extra long tag 19 separating the batches of an
order were 1/2" longer than the normal batch tags,
the extra short tag would be 1/2" shorter to avoid
misregistration of subsequently printed tags. This
relationship is readily apparent from FIG. 6.
Thus, the stacker-printer according to the
invention provides two or more levels separation of
tags into batches and into groups o~ batches, and if
desired, additional levels of separation may be
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provided, ~or example, by providing a medium length
tag (e.g., 1/4" length) such as the tag 21 (FIG. 6).
This tag would then be followed by a medium short tag
21'. Also, the extra long tag 19 can be made suffi-
ciently long to permit an order number or other iden-
tifying information to be printed at the top of the
tag so that the batches of that group can be identified
by order number or other~ise. This identifying infor-
mation may also be printed elsewhere, such as, for
example, the purchase order number printed on the tag
19 of FIG. 6. In this case, the tag may be identiEied
as a header tag as illustrated by the letters ~D. TAG
printed on the top of the tag 21. Finally, because
the tags 17', 19' and 21' are produced only for the
purpose of reregistering the web indices 41, they are
generally left blank; however, they could contain
information if desired.
Because the tags are segregated into batches,
it is important that sequence integrity of the ~ags
be maintained to prevent the tags from various batches
from being intermixed. However, if a tag becomes
caught in the chute 38 and causes other tags to jam
up behind it, the sequence integrity can be lost. If
a large number of tags jam up in the chute before the
jam is detected, the tags must be manually resorted
by the operator, a procedure which can be quite time
consuming. Therefore, in accordance with another
important aspect of the invention, a chute tag sensor
44 is employed to sense the presence of a tag 18 in
the chute 38. The sensor 44 can be any suitable sensor,
but in the present embodiment is an optical sensor
that contains a light source as well as a photoelectric
detector to detect the presence of a tag by detecting
the light reflected therefrom. The sensor cooperates
with a microprocessor within the printer as well as a
13 ~2~
counter that counts the number of tags that have been
printed (both described in a subsequent portion of
the specification) to determi-ne the number of tags
present in the chute 38. If more than a predetermined
number of tags, such as, for example, two or three
tags are printed subsequent to the detection of a tag
in the chute 38, and a tag is still present in the
chute 38, a chute jam condition is indicated and the
printing is stopped. Consequently, since only two or
three tags need to be sorted after the occurrence of
a jam, the operator time necessary to restore sequence
integrity is substantially reduced.
A web index sensor 46 is used to sense the
indices 41~ The indices 41 may be any suitable indices,
such as, for example, printed marks, notches or holes,
but in the illustrated embodiment, the indices 41 are
formed by fluorescent material disposed along one
edge of the web 16. The sensor 46 may be any suitable
sensor, but in the illustrated ~mbodiment includes a
source of ultraviolet light 48 and a photoelectric
sensor 50. The source of ultraviolet light 48 excites
one of the fluorescent indices along the edge of the
web 16 as it passes thereunder and causes it to
fluoresce. Because of the relatively slow decay time
of the fluorescent material, the fluorescent material
continues to fluoresce for some time after being exposed
to the ultraviolet light. This fluorescence is detected
by the photoelectric detector 50 as the index passes
thereunder.
Finally, a conveyor sensor 52 senses the
presence of tags thereunder (FIG 4) and provides a
signal indicating the stacker is full and stops the
printing process. The sensor 52 is similar to-the
chute sensor 44 in that it contains a light source
and photoelectric detector that detects light reflected
-14
from the tags. The sensor 52 may be defeated by
lowering a ramp 54 thereover as is illustrated in
FIG. 3 in order to prevent the tags from passing under
the sensor 52~
Data is input into the printer according to
the invention by a data input terminal 51 (FIG. 7)
which may be a cathode ray tube data input terminal,
another computer or simply a keyboard. The output of
the data input 51 may be in various forms, for example,
in the form of ASCII characters which are applied to
a processor 53 within the printer via an interface
54. The function of the processor is to receive data
from the data input terminal 51 and to convert it to
a form suitable for driving the print head 28, the
web advance motor 26, the cutter 34, the stacker motor
42 and the carriage motor 30 in order to generate the
desired characters at the desired positions on the
web being printed, to cut the web into tags of appro-
priate lengths and to stack the cut tags in an appro-
priate manner.
The system according to the present invention
stores various types of information. The information
that is stored includes information defining the various
fonts, which is stored in a font storage location 56;
data defining the format in which a particular tag or
label is to be printed, which is stored in a format
storage location 58; and data defining the alphanumeric
characters that are to be printed, the format tha~ is
to be utilized, the number of tags to be printed and
the type of stacking required, which is stored in a
data storage location 60.
In a typical system, the data stored in the
font storage 56 is preprogrammed and generally cannot
be changed by data input from the data input 51. The
data from the data input 51 merely selects which
~2~
characters are to be printed. The format storage 58-
is programmable by data input from the data input 51
and is used to define the field in which the characters
are to be printed. The data entered in the format
storage defines the skeleton or outline oE the tag to
be printed and includes such information as the font
of each character, check digits which may be printed,
whether or not the line of characters has a fixed
length, whether certain characters are always printed,
and the location on the tag where the characters are
to be printed~ In addition, the length and width of
the tag necessary to accommodate the selected format
is stored in the format storage. This information is
printed whenever a new format is selected to assure
that the operator has placed the correct size web
in~o the printer. The number of tags to be printed,
as well as the number of tag sections to be printed
between cuts, is also stored in the format storage 58
in order to control the cutter 34 to cut the tags to
the length, and to insert the longer and shorter tags
between batches, and between groups of batches, as
previously discussed.
The data stored in the data storage 60
includes data representative of the particular charac-
ters to be printed on a tag. This data is used inconjunction with the format storage data and font
storage data, and printing is controlled by selecting
a particular font from the font data storage 56 and a
particular format from the format data storage 58.
The processor 53 then inserts data from the data storage
60 in the appropriate places defined by the format
storage 58 and prints the data in the appropriate
fonts defined by the font storage 56. When pri-nting,
the microprocessor 53 converts the data stored in the
data storage 60, the format storage 58 and the font
5~
16
storage 56 to signals that actually control the p~inting.
These signals take the form of carriage control signals
which are amplified by a carriage driver 29 which in
turn actuates the carriage motor 30 which controls
the movement of the print head 28. Other signals
which determine which pins of the print head are to
be fired or actuated are amplified by a print head
driver 66 and used selectively to actuate the various
pins of the print head 28. A paper advance driver 68
amplifies the signals from the processor 53 and controls
the position of the paper advance motor 26. A cutter
driver 36 amplifies the signals from the processor 53
and causes the cutter 34 to be activated at predeter-
mined intervals as determined by signals from ~he web
index sensor 46 and the data in the data storage 60
and the format storage 58. A stacker motor driver 72
amplifies signals from the processor 53 in order to
drive the stacker motor 42 in accordance with the
mode of stacking selected (shingle or pile) and the
data in the format storage 58 and the data storage
60~ The processor 53 also receives signals from the
chute tag sensor 42 and the conveyor sensor 52 r and
terminates the printing in the event of a jam in the
chute or a full stacker.
Stacker-Printer Operation and Logic
The mode of operation of the stacker-printer
can be selected by the operator by any suitable input
to the data input 51. In the illustrated embodiment,
the stacker-printer is designed to operate in four
modes which may readily be selected by the operator
via the data input 51. The four modes are a shingle
only mode, a shingle mode with batch separation, a
shingle de with an extra long tag and printing at
the top of the extra long tag, and a stack in piles
mode where up to 30 tays may be stacked in a single
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pile.
In the shingle only mode, tags exit the
exit chute 38 and slide onto the conveyor belt 40 as
illustrated in FIG. 1. In this mode, each time a tag
exits the chute 38~ the conveyor belt 40 is incremented
a predetermined amount, generally on the order of
approximately 1/4", to achieve the shingle effect.
In this mode, the ramp 54 may be lowered to the posi-
tion illustrated in FIG. 3 to permit the tags to be
turned upright to permit a large number of tags to be
stored in the stacker. Alternatively, the ramp 54
may be placed in an upward position as illustrated in
FIG. 4 to permit the tags to be sensed by the sensor
52 when the stacker is full.
The shingle mode with batch separation is
similar to the shingle only mode except that the last
tag of a batch is made longer, for example, 1/8" longer
than a normal tag. The long tag is followed by a tag
that is, for example, 1/8" shorter than a normal tag.
The short tag is preferably a blank tag.
The shingle mode with the extra long tag
with printing at the top is similar to the shingle
mode with batch separation except that the extra long
tag is longer than the long tag used in the batch
separation mode, for example, 1/2" longer than a normal
tag. The extra long tag is followed by an extra short
tag that is, for example, 1/2" shorter than a normal
tag. In addition, the very top of the extra long tag
may be imprinted with information identifying the tag
as a header tag, or identifying a batch number or an
order number in order to permit the tags to be readily
identified. The shingle mode with the extra long tag
may be used in conjunction with the shingle mode with
batch separation to provide two levels of separation,
for example, separation between batches by means of
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the long and short tags, and separation between groups
of batches or orders by means of the extra long and
extra short tags. This permits the operator to identify
orders and separate batches with minimal effort, par-
ticularly when an order contains a large number of
small batches. Also, as previously discussed, addi-
tional levels of separation may be provided by utilizing
separation tags of various lengths.
In the batch separation mode and in the
extra long tag mode, the web 16 is advanced by the
paper advance motor 26 until an index mark is sensed
by the sensor 46. When a long, extra long tag or
other length separation tag such as a medium length
tag is called for, the web 16 is then advanced the
appropriate additional length required for a batch
separation tag, an extra long or medium length tag t
and printed at the top or not printed as mode requires.
In this mode, the ramp 54 may be pcsitioned either
down or up as shown in FIGS. 3 and 4, respectively.
In the stack in piles mode, the conveyor
belt 40 is not advanced after each tag is printed as
in the case the shingle modes, but rather, the conveyor
belt 40 remains stationary until any desired number
of tags up to, for example, 30 tags, are printed.
After the desired number or the 30 tags have been
printed, or after a batch is completed, the conveyor
belt 40 is advanced by an increment approximately
equal to or slightly greater than the width of the
stack tags, and a new pile is started as shown in
FIG. 13. ~y advancing of the conveyor 40 an amount
tailored to suit the width of the tags being printed,
maximum density within the stacker is achieved. In
the stack in piles mode, the ramp 54 is preferably
maintained in the raised position as illustrated in
FIG. 4 to assure that the printing is terminated when
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the stacker is filled and a tag is sensed by the sensor
52. With the ramp 54 raised as shown in FIG. 4, the
stacker cannot be over-filled and cause the stacks to
be piled on top of each other.
The logic employed in the control of the
stacker to achieve the four modes described above is
illustratea in FIG. 8 and described below. As can be
seen from FIG. 8, after the mode of operation has
been loaded into the system, the processor 53 determines
which mode has been selected. For example, in the
logic illustrated in FIG. 8, the system first determines
whether the mode is a batch separation mode. If a
batch separation mode has been selected, the system
determines whether the last tag of the batch is being
printed. If it is not the last tag of the batch, the
tag is cut after being printed, and the conveyor belt
40 of the stacker is incremented. The next tag is
then checked to determine whether it is the last tag
o the batch. If it is the last tag of the ba~chr a
determination is made whether the printing of the tag
has finished. When it has finished printing, the web
index sensor 46 and the paper advance motor 26 are
activated until the web index is found. After the
web index is found, the web is fed an additional length
equal to the long tag increment and cut. Finally,
the web is advanced to the next index and cut again
to produce the short tag, and to resynchronize the
indexes. The program then returns to the start.
If the batch separation mode is not loaded,
a determination is made whether or not the extra long
tag mode (or medium long tag mode) has been selected.
If the extra long tag mode (or medium long tag mode)
has not been selected, a determination is made whether
the stack in piles mode has been selected. If the
stack in piles mode has not been selected, the tag is
-20~ 59~
cut and the stacker is incremented to provide the
shingle mode of operation. However, if the stack in
piles mode has been selected, a tag counter is incre-
mented. The count in the tag counter is then compared
to determine whether the count is equal to the desired
number or the maximum number of tags in a pile, for
example, 30. If not, the tag is cut without advancing
the conveyor belt 40. However, if the tag count is
at the desired number, at its maximum, or the tag
being printed in the last tag in a batch, the tag is
cut and the conveyor 40 is moved by an amount approxi-
mate to or slightly greater than the width of the web
of sheet stock in the machine.
If the extra long tag mode (or medium long
tag mode) has been selected, a determination is made
as to whether the tag being printed is the last tag
of the group. ~f not, the tag is cut and the conveyor
belt 40 of the stacker is incremented. I~ it is the
last tag, a determination is made as to whether the
last line on the tag is being printed. If not, printing
continues until the last line is reached. When the
last line is reached, the web index sensor and the
paper advance motor are activated until the next web
index is found. After the web index is found, and if
printing is called for, the tag is incremented by the
extra long tag increment, the last line is printed on
the end of the tag in the area that corresponds to
the top of the extra long tag. The tag is then cut
and the web is advanced until the next index mark is
found. At this point, the web is cut to produce the
extra short tag and to resynchronize the web indices.
Chute Jam Detection
As previously discussed, in order to retain
the se~uence integrity of the tags exiting the~chute
38, a jam in the chute must be detected quickly.
-21-
However, any detection system must be able to accommo-
date the large variations in the speed of the tags
passing through the chute without falsely indicating
a jam when no jam exists, such as could occur, for
5 example~ when a slow speed is tag detected. To achieve
this function, an event counting system has been
developed. In this system, the chute sensor 44 deter-
mines whether a tag is present in the chute while the
next tag is being printed. If a tag is present, a
counter is incremented once, and the count of the tag
being printed is noted. If a tag is still present in
the chute after that tag has been printed and the
subsequent tag is being printed, a chute jam condition
exists, and printing is terminated after the tag being
printed is completed. The jam condition must be
corrected by the operator before printing can be
resumed. Thus, the jam condition is detected after
only two tags (or any desired number of tags, for
example, 1 to 4) have been printed subsequent to the
occurrence of the jam.
The logic associated with the chute jam
detection system is illustrated in FIG. 9. As illus-
trated in FIG. 9, the status of the chute sensor ~4
is monitore~. If there is no tag in the chute, any
jam flag that may have been previously set is cleared,
and the system continues to monitor the chute status.
When a tag is detected in the chute, the present tag
count is loaded into a counter and compared with a
previously loaded tag count. If the count is the
same, indicating that no new tags have entered the
chute since the presence of a tag in the chute was
detected, no action is taken, and the system continues
to monitor the status of the chute sensor ~4. -If the
count is not the same, indicating that an additional
tag has entered the chute since the presence of a tag
~2~L5~
-22-
in the chute was first detected, the event counter
and the tag count are updated. The event counter is
then sampled, and if the count in the event counter
is less than two (or any other suitable number such
as 1, 3, 4, etc.), no action is taken, and the moni-
toring of the chute sensor continues. However, if
the number in the event counter is equal to two (or
whatever number has been selected), a jam flag is set
to instruct the printer to stop printing at the end
of the tag currently being printed.
Stock Width and Length Check
The width and length check is employed when-
ever a change in format occurs between batches. When
a format change occurs, the length and width of tags
necessary to accept the format are calculated and
compared with the length and width of the stock pre-
viously loaded into the printer. If the stoc~ loaded
in the printer is not compatible with the requirements
of the new format, information defining the necessary
length and width is printed onto the stock then in
the printer in a format small enough to fit onto the
smallest stock that can be accepted by the printer.
Printing then terminates, and the operator must load
new stock into the printer before printing can resume.
Thus, the system minimizes the chance of damage to
the print head which can occur as a result of printing
direc~ly on the platenl and also minimizes possible
damage to the ribbon and wasted supplies.
The above function is performed by the system
which compares the length and width requirements of
the new format stored in the format storage 58 with
the length and width requirements of the format of
the previously printed batch. If the values are not
the same, the messa~e with the correct values is printed.
A sensor senses the position of an out of stock switch
-23-
(not shown) or a printer carriage open switch 74 (FIG.
2) to determine that the stock has been changed. The
operator then enters data defining the width of the
stock jus~ loaded into the system via the data input
51. Alternativelyl a width sensor (not shown) that
automatically senses the width of the web may be
provided. The length information is determined
directly from the newly loaded web by sensing the
distance between web indices on the stock via the web
index sensor 46. If the width and length information
~hus loaded now concurs with the requirements of the
selected format, printing may proceea. If not, the
tag length and width required hy the selected format
is again printed on the web and printing is terminated.
The logic employed by the stock width and
length check is illustrated in FIG. 10. As illustrated
in FIG. 10, the required width is converted to binary
and true width is calculated by multiplying the width
requirements of the format stored in the format storage
58 by the number of parts forming the tag in the event
that a multiple part tag is being printed. For example,
if two-part tags such as those illustrated in ~IG. 6
were utilized, the format width requirement would be
multiplied by two. The required stock width is compared
with the width of the stock presently loaded in the
machine. At the same time, a determination is made
as to whether or not the previous value of stock width
was zero, with zero indicating either that new stock
was put into the machine or that a power up condition
exists. If the previous value is zero, the new width
is loaded as the present width, and the stock length
comparisons are made. If the previous value of width
is not zero, the comparison between the previo~s and
present stock width is made. If the two values are
the same, the stock length comparisons are made. If
~ 5~
-24-
not, the check width indicator and the print flag are
set before the stock length comparisons are made.
After the stock length comparisons are made, if there
is an error, the check length indicator and the print
flag are set. A determination is then made as to
whether any flags are set. If not, the printing of
tags commences. If a print flag indicative of an
incorrect width or an incorrect length has been set,
a single tay with the tag length and width requirements
required by the selected format is printed. The
printing of length and width information is done in a
format that can be accommodated by the smallest tag
that can be utilized by the printer. No further
printing occurs until the stock is changed.
lS Automatic Len~th Detection
The stock length check described above,
provided automatically by automatic length detection
circuitry assures, that the length of the tag s~ock
loaded in the machine is compatible with the selected
format to thereby minimize the possibility of printing
onto wrong or faulty stock. The detection is automati-
cally achieved by comparing the spacing between web
stock indices with the spacing required by the selected
format.
The logic for accomplishing the length detec-
tion is illustrated in FIG. 11. As is illustrated in
FIG. 11, the required tag length, as determined by
the format storage 58, is loaded and the number of
steps that must be applied to the paper advance motor
26 to advance the web 16 an amount equal to the required
tag length is calculated. The web 16 is then advanced,
and the steps are counted as each tag is prin~ed.
The counts are then compared to a stored step eount
representative of the maximum length of tag that can
be tolerated by the system. If the step count reaches
-25-
a number representative of the maximum length, a jam
condition is indicated. As long as the step count is
less than the maximum length representative count,
the web index sensor 46 is monitored until a web index
is found. ~hen the web index is found, the step count
present at the time the web index is detected is com-
pared with a stored count indicative of the minimum
length of tag usable with the selected format. If
the count is less than or equal to the count corres-
ponding to the minimum length of tags that can beutilized with the selected format, a jam condition is
indicated. If not, the monitoring continues.
When printing a large number of tags, it is
useful to run several printers simultaneously, with
one of the printers being utilized as a master printer
to control one or more remote printers. Howeverl one
problem that arises when seYeral printers are being
run simultaneously is that, because o~ variations in
mechanical tolerances between the printers, the tags
printed by the various printers do not have identical
print placement. This occurs because the increment
that the web 16 is advanced by the stepping motor 26
in response to a given number of pulses varies from
printer to printer. An error as little as 0.0005
inch per step can accumulate over the length of a tag
to produce unacceptable printing, with print placement
variations between printers varying as much as ~0.20
inch over a two inch long tag. I'his variation is
readily noticeable, particularly when several printers
are being operated simultaneously, because the tags
produced by the various printers can be readily compared.
One possible solution to this problem is to
adjust the various printers by adding or subtracting
a fixed increment from the amount that the tag is
advanced prior to the printing of the first line or
-26- ~2~
some other line~ However, this solution is not entirely
satisfactory because the variation in line placement
is not fi~ed. Rather, because the variation in line
placement is the result of the accumulation of minute
errors that occur during each step of the advance,
the line placement error varies as a function of line
position, with the error being greater for line posi-
tions corresponding to greater tag advance positions
than for line positions corresponding to lesser tag
advance positions.
Therefore, in accordance with another impor-
tant aspect of the invention, there is provided a
system that can adjust the printer so as to control
the print placement from printer to printer to within
a tolerance of +0.010 inch. This is accomplished by
varying the position of each line on a dynamic basis
as a function of the position of the line relative to
the top or bottom of the tag.
The effects of the accumulated error resulting
from mechanical tolerances as well as the effects of
the dynamic correction are illustrated in FIG. 14~
Two representative tags are illustrated in FIG. 14,
with the tag on the left having been printed without
the correction, and the tag on the right having been
printed by a printer utilizing the dynamic correction
according to the invention.
In the tags illustrated in FIG. 14, a several
lines of print, as represented by a series of L's,
are printed on each tag near associated lines of pre-
printed material relating to price, manufacturer,style and other information~ When printing lines of
information on such preprinted tags, it is desirable
to print the various line~ of information near the
associated preprinted lines; however, because the
spacing between the lines of the pre-printed material
-27-
is fixed while the spacing between the lines printed
by the printer varies as a function of the mechanical
tolerances of the printer, the distance between the
lines of preprinted material and the lines printed
by the printer varies as a function of the position
of the printed line on the tag. This phenomenon is
illustrated in the left tag 18 of FIG. 14 which shows
the line of print associated with the term "PRICE" to
be printed fairly closely to the word "PRICE", while
the line of print above the word "CLASS" is spaced
further from the preprinted line "CLASS", and the
line printed above the preprinted line "MFG STY" is
even more spaced therefrom. Thus, it is apparent
that any adjustment for printed error must be provided
on a dynamic basis in order to obtain equal spacing
between the preprinted and printed material. Such
dynamic correction is illustrated in the right tag 18
of FIG. 14 which employs the dynamic correction
according to the present invention described below.
In order to determine whether a particular
printer requires feed distance compensation, a tag
having calibrations printed thereon is fed through
the feed printer. A calibration format is entered
into the printer, and one or more tags are printed.
The tags thus printed arè then examined to determine
whether the data printed on the calibrated tag is
located at the proper position as defined by the format.
If so~ no feed distance compensation is required. If
not, the required compensation can be deduced from
the calibrations on the calibrated tag. The compensa-
tion takes the form of a number which is a submultiple
of the total number of steps that the web must be
advanced before the desired line position is r~eached.
This number is entered into each printer, and serves
to modify the format data that defines the position
~2~
-2~-
of each line to be printed received from the master
printer. This number may conveniently ran~e from
zero to seven so that it may be stored in a three-
stage shift register. In addition, a plus or minus
indicat:ion may be stored in a fourth register stage
to indicate whether the number stored in the other
three stages is to be used to increase or reduce the
amount of the tag advance increment between lines.
In a practical system, the number may be entered
manually by a switch on the printer which may conve-
niently be a four-stage switch such as the switch 76
which contains four binary switches tFIG. 1) or any
other suitable switch. In the illustrated embodiment,
three switches of the switch 76 define the magnitude
of the error indication, and the fourth switch defines
whether the error indication is positive or negative.
The operation of the feed distance compensa-
tion system according to the invention can be best
explained with reference to FIG. 12. As illustrated
in FIG. 12, the system first determines whether any
feed distance compensation is necessary. This deter-
mination is made by checking the compensation number
entered ito the printer. For purposes of discussion,
this number will be referred to as a "switch setting",
with the "switch" taking the form of a three-stage
binary switch having a range of switch settings from
zero through seven. In such a system, the determina-
tion of whether or not feed distance compensation is
required can be readily ascertained by noting the
switch setting. If the switch setting is zero (or
000 in binary form~, no compensation is required. If
the ~witch setting is anything other than zero, compen-
sation is required.
As previously stated, the system according
to the invention serves to adjust the line feed
$~
-29-
distance by modifying the advance increment called
for by the format of the tay being printed by a sub-
multiple of that distance as determined by the switch
settiny. Thus, if no compensation is required, the
advance increment or feed distance called for by the
format and expressed as a discrete number of stepping
motor steps, is stored ln an unmodified form and used
to control the advance increment or feed distance of
the printer.
If modification of the feed distance is
required, the feed distance for a particular line, as
determined by the tag format, is temporarily stored
so that it can be modified by the system. In the
illustrated embodiment, this feed distance is divided
by a predetermined integer to provide a number repre-
sentative of a submultiple of the feed distance. In
the illustrated system where the switch setting ranges
from zero through seven, a convenient number for the
integer by which the feed distance is to be divided
is thirty-two. Tnis permits the feed distance as
determined by the master printer to be increased or
decreased by increments of 1/32 of the feed distance,
ranging from no adjustment to increments of up to +7/32
of the feed distance. If coarser or finer incre-
ments are desired, the integer by which the the feeddistance is divided as well as the number of stages
in the switch may be adjusted accordingly.
Once the feed distance has been divided by
thirty-two, a test is made whether or not the original
feed distance is to be increased or decreased. This
is accomplished by determining the state of the fourth
stage of the switch. For example, if the fourth stage
of the switch indicates that the feed distance is to
be reduced, an increment as determined by the switch
setting is subtracted from the feed distance, whereas
-30-
i the fouxth stage of the switch indicates that the
feed distance is to be increased, the increment is
added to the feed distance.
The increment that is to be added or sub-
S tracted from the feed distance provided by the masterprinter is determined by multiplying the switch setting
by the quotient that is obtained by dividing the feed
distance by the predetermined integer (in this case,
32). For example, if the switch setting were, for
example, seven, and the feed distance for a particular
line as provided by the master printer were, for example,
320 steps, the increment to be added or subtracted
would be equal to 70 steps, or 320 divided by thirty-
two and multiplied by sevenO This increment would
then be either added to or subtracted from the feed
distance received from the master printer depending
on whether the feed distance needed to be increased
or decreased. In the present example, if the feed
distance had to be decreased, the 70 step incr~ment
would be subtracted from the 320 step feed distance
to provide an adjusted feed distance of 250 steps
(320 minus 70 equals 250). Conversely, if the feed
distance had to be increased, a new feed distance of
390 steps (320 plus 70 equals 390) would be calculated.
This adjusted feed distance would then be stored in a
memory within the individual printer and used instead
of the feed distance provided by the master printer.
This process would automatically be repeated for each
line of print called for by the format until an adjusted
feed distance for each line of print would be calculated
and stored.
As is apparent from the above description,
because the increment by which the feed distance is
adjusted is determined by both the switch setting and
the feed distance provided by the master printer, the
- - ^
~2~5~
-31-
~ncre~ent vari~ as ~ ~unction of the d~tance of a
line o~ print ~ro~ th~ top of th~ t~g. ~oreover,
~uch ~ ~a~iabl~ increment i achieved with ~ingle
setting without the need for a eparate ~witch ~tting
for each for~at or for each line to be printedr ~his
being the c~se, lt ~B not critical where the line on
th~ callbration tag ufied to determine the switch setting
~ po~itioned with respect to the top or bottom of
the tag. ~owever, as i~ apparent from FIG. 14, because
the correction incre~ent is greater for lines near
tbe top o~ the ~ag (those requirlng a greater ~9
~dvance) than ~or those near the bottom of the tag
(tho~e re~u~ring little tA9 adv~nce), it i~ prefer~ble
to position the llne on the cali~ration tag near the
top of that t~g, since thi~ permits ~mall error~ to
b~ ~ore re~dily a~certa~ngd.
ObQiously~ ~any ~odifications and variations
of th~ pr~sen~ invention ~re possible in light of ~he
aboYe teachi~gs. Thus, lt i~ to be understood tha~,
withi~ the scope of the appended claims, the invention
~ay be present otherwi3e than a~ ~peci ically described
~bove.
.
