Electrographic label printing system

An electrographic label system is disclosed whereby flexographic and electronic printing are combined in a modular design to produce multi-color labels. Label stock is unwound from a roll and passes over an automatic shut off roller that shuts down the entire printing process and stops the flow of label stock when it runs out so that a new roll of stock can be sliced to the old roll and rethreading the system is not necessary. A back slitter having a roller cutter cuts the desired height of the label leaving a feed strip between the label and opposite edge. The label stock is fed into a flexographic printer having a drum which imprints a first image, cuts the label to the correct length, and imprints a register mark on the feed strip. The label stock material is next fed into an electronic printer interfaced with a computer or programmable logic controller which imprints a second image upon each label. Upon exiting the electronic printer, the label stock is wound into a roll by a takeup spool or automatically dispensed onto the product or package.

BACKGROUND OF THE INVENTION 
Labels affixed to products for identification purposes are printed in 
various ways. One of the most common and inexpensive methods of printing 
labels employs a flexographic printer. A flexographic printing plate is 
manufactured having the opposite image of the label. The plate is attached 
to the drum of the flexographic printer. With each revolution of the drum, 
ink is applied to the plate and the plate then makes contact with the 
label material and imprints the label image thereon. When this type of 
printing process is employed, all of the label information, including 
product name, trademarks, brand name, tag lines, descriptions, 
ingredients, weight, volume, fanciful design elements, etc., must be 
printed simultaneously. If any of this information must be changed or 
modified, at least a portion of the flexographic printing plate must be 
remanufactured. If the label changes are substantial, a new printing plate 
must be manufactured. 
Alternatively, labels can be printed using one of many types of electronic 
printers. These printers are typically connected to computers or 
programmable logic controllers (PLCs) and include laser printers, ink jet 
printers, thermal/thermal transfer printers, spray printers, dot matrix 
printers, and the like. The information to be printed upon each label is 
entered and stored within the computer or PLC which in turn sends the 
information to the printer. This method of printing labels is typically 
inefficient. More time is required to print each label. The more or 
fancier the information, the more time consuming the process. The quality 
of labels printed entirely by electronic printers is often inferior. While 
flexographic printers have the capability of custom die cutting label 
stock, labels printed electronically must be printed on pre-die cut label 
stock. Misalignment of the stock in the electronic printer can cause 
numerous problems. 
Neither of the above label printing processes can easily print two-color 
labels. 
The present invention combines flexographic label printing with electronic 
label printing in order to produce one or two-color labels having a 
variety of information elements including information that is used 
regularly on a group or type of label (permanent copy) and information 
that is changed from one label batch to the next (variable copy). It is an 
object of this invention to provide a label printing system meeting this 
criteria. It is a further object to provide such a system that is 
contained as one integral unit. It is further an object to provide such a 
system that is easy to use and produces high quality labels. These and 
other objects of the invention will become apparent in the following 
descriptions. 
SUMMARY OF THE INVENTION 
The invention comprises an electrographic printing system whereby a label 
having a two-part image is produced. The system includes two printers, a 
flexographic printer and an electronic printer. 
Label stock is unwound from a roll and passes over an automatic shutoff 
roller and splicer. The automatic shutoff roller shuts down the entire 
printing process and stops the flow of label stock when it runs out so 
that a new roll of label stock can be spliced using the splicer to the old 
roll and rethreading the system is not necessary. Next, a back slitter 
cuts through only the label portion of the label stock. The backing or 
liner that serves as a carries to which the label stock is adhered to is 
not cut. The back slitter comprises a roller-cutter. The narrow margin 
portion of the label stock cut by the back slitter serves as a feed strip 
used to advance the label stock through the flexographic printer. 
The first image is printed flexographically by a flexographic printer. This 
portion of the label typically will have a permanent nature. It may 
comprise the manufacturer's name and address, a fanciful border, a brand 
name, a trademark, or a tag line. It is the type of information that will 
not change from specific product to specific product. The flexographic 
printer also laterally but cuts or die cuts each individual label on the 
label stock. The thin band or feed strip formed by the back slitter 
remains along one edge of the label stock material. This feed strip serves 
two purposes. First as indicated above, it is utilized to feed the label 
stock through the flexographic printer. It adds to the strength of the 
label stock material after the labels have been die cut and only the label 
backing or liner remains in a contiguous state. Second, a small register 
mark comprising a dot or similar geometric shape is flexographically 
printed on the feed strip. This register mark is located at a 
predetermined position with respect to the flexographically printed image. 
When the label subsequently enters the electronic printer where additional 
information is thermally printed on the label, the electronic printer 
reads the location of the register mark. Once the position of the register 
mark has been determined, the electronic printer knows where to print the 
second part or portion of the label image. This second printed portion is 
information that must be changed or modified from one batch of labels to 
the next. It is likely to include a product name, product size, product 
weight, universal product code, product price, or other specialized 
information. 
The electronic printer is preferably a thermal/thermal transfer printer 
which is controlled by a computer or programmable logic controller (PLC). 
The operator or system can easily change or modify the information that is 
electronically printed on each label. Once the information has been 
entered into the computer or PLC and stored, it can be easily recalled and 
does not have to be reentered. 
Finally, the printing system includes an optional label dispenser which 
dispenses each label individually by removing the label from the label 
backing and applying the label to the particular product or package to 
which it corresponds. The label backing is wound onto a takeup spool that 
can be disposed of or recycled when full. The speed of the label dispenser 
is correlated with the speed of the product such that proper label-product 
alignment is achieved. A clutch assembly controls the takeup spool on 
which the label backing is wound. If the optional label dispenser is not 
employed, the fully printed labels are simply wound onto the takeup spool 
into a roll similar to that of the blank label stock material.

DETAILED DESCRIPTION 
Although the disclosure hereof is detailed and exact to enable those 
skilled in the art to practice the invention, the physical embodiments 
herein disclosed merely exemplify the invention which may be embodied in 
other specific structure. While the preferred embodiment has been 
described, the details may be changed without departing from the 
invention, which is defined by the claims. 
The invention 10 comprises an electrographic label printing system having a 
base 15, a label stock dispenser 20, a back slitter 50, a flexographic 
printer 60, an electronic printer 120, and a label takeup spool 160. Blank 
label stock 22 on a roll 30 is initially withdrawn from dispenser 20, and 
back slit by back slitter 50. The back slit label stock 22 enters 
flexographic printer 60 where the flexographic label image or permanent 
copy 100 is printed, a register mark 108 is printed, and the individual 
labels 110 are laterally cut at 102. The label stock 22 next enters an 
electronic printer 120 where the electronic label image or variable copy 
140 is printed. Finally, the label stock 22 having fully printed labels 
110 thereon is wound around label takeup spool 160. 
As shown in FIG. 1, blank label stock 22 on a roll 30 is rotatably mounted 
onto label stock dispenser 20 which includes a clutch assembly 24. The 
clutch assembly 24 comprises a spring 26 and a knurled nut 28. The spring 
26 is biased between the roll 30 and the nut 28 such that it exerts a 
constant force upon roll 30. Due to this force, label stock 22 is not 
permitted to freely roll off of roll 30 and some pulling force is required 
for the label stock 22 to be dispensed. 
The label stock 22 next engages auto shutoff roller 40. Threaded properly, 
the label stock 22 supports roller 40 in an upwardly biased position. When 
label stock roll 30 runs out, label stock 22 can no longer support auto 
shutoff roller 40 in the upwardly biased position. When roller 40 falls to 
its lower position, the entire system 10 shuts down. At this point, a new 
roll 30 of label stock 22 can be loaded onto label stock dispenser 20 and 
spliced to the end of the previous roll 30. An optional splicer may be 
attached adjacent to shut off roller 40 to facilitate the splicing of two 
rolls 30 of label stock 22. By stopping the system before the end of the 
previous roll 30 is advanced through the system 10 the need to rethread 
the entire system 10 is eliminated. Once the new roll 30 is loaded and 
spliced, the new roll 30 is manually turned backward so that auto shutoff 
roller 40 is biased upward again into its operating position. The clutch 
assembly 24, discussed supra, applies an adequate amount of friction 
against the roll 30 so that when label stock 22 is properly threaded, auto 
shutoff roller 40 is maintained in the upward biased position. 
Label stock 22 next proceeds into back slitter 50 where the label portion 
32 of label stock 22 is slit at 104 parallel to label stock edge 36. The 
resulting label stock material 22 is best shown in FIGS. 3 and 7. The 
narrow strip portion or margin between the slit 104 and edge 36 forms a 
feed strip 106. The remaining portion 110 is the portion of the label 
stock 22 where the actual labels will be printed. 
Label stock 22 consists of a top portion or label portion 32 and a bottom 
or backing portion 34. The back slitter 50 only cuts through the top 
portion 32 leaving the backing or liner 34 in tact. Thus the label stock 
22 remains an integral strip of material even after back slitting. 
Label stock 22 next enters flexographic printer 60 at the flexographic 
printer input 58. The mechanism of the flexographic printer is shown in 
FIG. 2. The printer 60 includes a print cylinder 62 having a metal core 
64. A layer of cushion material 66 encases the exterior drum surface 65 of 
the print cylinder 62 except for metal edge portion 67. The print cylinder 
62 rotates on a central axis 63. 
Removably fixed, typically by means of an adhesive, to the cushion material 
layer 66 and metal edge portion 67 of print cylinder 62 is a flexographic 
printing plate 68. The plate 68 prints the flexographic label image or 
permanent copy 100 on portion 110 of the label stock 22. The cushion 
material 66 allows for compression of the portion of the printing plate 68 
attached to the cushion material 66 when it is brought against the label 
stock 22. The plate 68 is best shown in FIGS. 4 and 5. Attached to the top 
surface of plate 68 are two raised portions 70 an 72. The larger raised 
portion 70 contains a reversed image 98 of the permanent copy 100 to be 
imprinted flexographically on label portion 110. Smaller portion 72 prints 
a register mark 108 on the feed strip 106 of the label stock 22. 
Referring to FIGS. 2 and 3, the ink supplying apparatus can be seen. The 
ink color used to print the flexographic image or permanent copy 100 must 
be different from the color used to print the register mark 108. 
Furthermore, the ink used to print the register mark 108 must be optically 
readable. 
A foam roller 80 is impregnated with the desired color of ink for permanent 
copy 100. Roller 80 tangentially contacts engraved surface roller 82. A 
precisely metered amount of ink is transferred from foam roller 80 to 
engraved surface roller 82 at this line of contact. Engraved surface 
roller 82 in turn tangentially contacts raised portion 70 of flexographic 
printing plate 68 during a portion of the revolution of print cylinder 62. 
Engraved surface roller 82 deposits an exact of amount of ink on the 
raised portion 70 of the plate 68. The amount is sufficient to imprint one 
image 100 on the label stock 22. Similarly, foam roller 76 which is also 
impregnated with an opaque colored ink, is in tangential contact with 
engraved surface microroller 78. Smaller raised portion 72 contacts 
microroller 78 whereby a precisely metered amount of ink is transferred to 
print a register mark 108 on feed strip 106. After inking, portions 701 
and 72 of flexographic printing plate 68 come into contact with label 
stock 22. An anvil shaft 86, as shown in FIG. 2 is provided to firmly 
press label stock 22 against portions 70 and 72 so that a high quality 
image 100 and a register mark 108 are produced. 
An additional structure is also attached to print cylinder 62. A straight 
cutting die 74 cuts or laterally perforates the top layer 32 of the label 
stock 22. The cutting operation similarly occurs when anvil shaft 86 
presses label stock 22 firmly against cutting die 74. 
Attached to flexographic printing plate 68 as shown in FIG. 4 is a raised 
feed strip portion 84. The feed strip portion 84 is positioned exactly 
above metal edge portion 67 of print cylinder 62 when flexographic 
printing plate 68 is attached to print cylinder 62. This long rectangular 
strip 84 feeds the label stock 22 through the flexographic printer 60. The 
label stock 22 is captured between feed strip portion 84 and anvil shaft 
86. Because feed strip portion 84 rests upon metal edge portion 67 and not 
on cushion material 66, there is less resilience between feed strip 
portion 84 and anvil shaft 86 allowing the label stock 22 to be pulled 
into flexographic printer 60. 
As print cylinder 62 rotates on axis 63, label stock 22 is drawn around 
cylinder 62 and ultimately is pressed into contact with raised portions 70 
and 72 by anvil shaft 86. At this line of contact, the image 100 from 
large portion 70 and the register mark 108 from smaller portion 72 is 
imprinted upon label stock 22. The feed strip portion 84 in conjunction 
with larger area 70 determines the length of the label or where the label 
is cut by cutting die 74. Because the label stock 22 is only fed through 
the flexographic printer 60 when the label stock is captured between anvil 
shaft 86 and raised feed portion 84, the length of raised feed portion 84, 
which is typically slightly longer than larger portion 70, determines the 
length of the label by controlling how much label stock 22 is fed through 
flexographic printer 60 before cutting die 74 comes into alignment with 
anvil shaft 86. 
Label stock 22, now cut laterally and having an image 100 and register mark 
108 imprinted, is fed through dancer rollers 116. Dancer rollers 116 pivot 
on dancer roller axis 118 and take up any extra slack in label stock 22. 
Label stock 22 next enters electronic printer 120 at electronic printer 
input 122. A thermal/thermal transfer printer is used in the preferred 
embodiment. The electronic printer 120 includes feed rollers which grip 
label stock 22 including liner 34 and draw label stock 22 into electronic 
printer 120. The electronic printer 120 also includes an electronic eye 
124 located above the area where feed strip 106 enters electronic printer 
120. The electronic eye 124 reads each register mark 108 and then sends a 
signal to the printing head of electronic printer 120. Once electronic 
printer 120 knows the location of register mark 108, electronic printer 
120 knows where to begin printing the variable copy or electronically 
printed portion 140 on the label stock 22. Using this system, it is not 
necessary to time or adjust the label stock 22 entering the electronic 
printer 120 so that the electronically printed portion 140 of the label 
110 is correctly positioned on each printed label 110. 
Electronic printer 120 is interfaced with a computer or PLC 126 having some 
type of data input means 128. The information (variable copy) to be 
electronically printed on each label 110 is entered at the data input 
means 128. Again, the variable information or copy 140 printed on each 
individual label 110 is the type of information that must be frequently 
changed such as exact product description, package contents, package 
weight, expiration date, etc. 
Finally, label stock 22 as shown in FIG. 1 exits electronic printer 120 and 
is wound around takeup spool 160. Takeup spool 160 contains a clutch 
assembly 162 similar to clutch assembly 24 on label stock dispensed 20. 
Clutch assembly 162 includes a spring 164 and a knurled nut 166. 
An alternative embodiment of the present invention 10 is shown in FIG. 6. 
Label stock 22 is dispensed from a roll 30 rotatably mounted to dispenser 
20. The label stock 22 next engages shut off roller 40 which again must be 
maintained in an upwardly biased position for the system 10 to operate. 
When label stock roll 30 runs out, a new roll 30 is spliced to the old 
roll 30 by utilizing splicer 54. The label stock 22 is next back slit or 
trimed at back slitter 50. While shut off roller 40 and back slitter 50 
are shown to be offset in FIG. 6, back slitter 50 could be moved outwardly 
so that it is directly over shut off roller 40. 
Label stock 22 is next fed into flexographic printer 60 where the permanent 
or flexographic portion 100 of the label and register mark 108 are 
imprinted and the label stock 22 is laterally cut. The label stock 22 
exits flexographic printer 60 and is threaded through dancer roller 116 
before it enters electronic printer 120 at 122 where electronic eye 124 
locates the register mark 108 and the variable copy 140 is added to each 
label 110. Upon exiting electronic printer 120, a stripper 150 strips away 
the excess portions of the top layer 32 of stock label material 22. The 
fully printed labels 110, still attached to backing material 34, can be 
either rewound on takeup spool 160 or fed through an automatic individual 
label dispenser 170 where each label 110 is individually removed from 
backing material 34 and brought into alignment with the product or package 
to which the label 110 is to be attached. 
The foregoing is considered as illustrative only of the principles of the 
invention. Furthermore, since numerous modifications and changes will 
readily occur to those skilled in the art, it is not desired to limit the 
invention to the exact construction and operation shown and described. 
While the preferred embodiment has been described, the details may be 
changed without departing from the invention, which is defined by the 
claims.