Note: Descriptions are shown in the official language in which they were submitted.
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1 Case T87
LASER PRINTER FOR CONTINUOUS-WEB
SUPPORTED LABELS
The invention relates to a laser printer for
labels supported on a continuous web for imprinting con-
tinuous webs and labels disposed on a label web wherein
the label web consists of a supPort web wound into a roll
with the labels consisting of paper, cardboard, metal
foils or Plastic being coated with an adhesive and remov-
abl~ adhering to the support tape and wherein the rol1 of
unimprinted label web is disposed at one end of a housing
receiving the whole arrangement and, after being im-
printed, is taken up again at the opposite end, the laserprinter including a fixing station which fixes the toner
transformed onto the labels from an image transmission
drum. The webs so generated, that is, the web rolls with
the imprinted labels carried thereon, are then supplied
to additional apparatus or equipment wherein the labels
are attached to the products to be labeled.
In connection with such web~label printers,
various printing equipment is used. Particularly if very
accurate images or very clear graphic representations are
required, laser printers are preferably utilized, that
is, printing equipment wherein an electronicallY con-
trolled laser beam produces an imprint on an image trans-
fer drum which then transfers the toner adhering thereon
onto a print surface where it is subsequently fixed in a
fixing station by the application of heat. Such laser
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printers generate not only very attractive letters or
pictures showing clearly even smallest details but they
can also be programmed in a simple manner via electronic
control devices. Continuous-web~label laser printers are
therefore utilized with increasing frequency in spite of
their relatively high prices. Difficulties in connection
with such laser printers are however encountered since
all components of such printers must be very precise and
the web to be imprinted must be precisely guided and fur-
ther the selection and location of the fixing station isquite important. As a result such printers are rela-
tively heavy, large and not easy to service. It is
therefore a first object of the present invention to pro-
vide a printer which with regard to its volume is small,
compact, lightweight and especially easy to work with and
to service.
The greatest difficulties reside in a suitable
arrangement of the fixing station. The fixing station in
which the dry powdered toner is melted on by application
of heat generally includes a drum which is heated to
about 200C and which is pressed onto the imprinted
paper. Under the pressure of the fixing drum, fine let-
ter or graphic outlines are widened such that they lose
their brilliance and, if these letters are very small,
become difficult to read. The particular disadvantage of
such fixing drums in connection with continuous-web/label
printers however resides in the fact that the adhesive
material and the printing material are strained, that is,
that adhesion of the labels to the products to be la-
belled becomes insufficient. Also, adhesive may be re-
leased at the edges of the labels and soil the hot fixing
drums and guide rollers to an unacceptable degree. It is
therefore a further obiect to provide a fixing station
for such a continuous-web~label laser printer which does
not have these disadvantages, that is, which does not
cause deterioration of the line sharpness on the labels
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3 Ca 5 e T87
and, particularly, which does not strain the adhesive and
the printing material.
The advantage of the warm fixing drums in the
known laser printers is that the fixing drum which, for
the usual materials is heated to about 200C, provides
for fast melting of the toner and its fixing on the sub-
strate. An equally fast handling is not possible with
other fixing methods, for example, by means of a flash
lamp as disclosed, for example, in U.S. Patent No.
10 3,871,761, since either the charging device cannot supply
the energy sufficiently fast or because the flash lamp
becomes overheated. Energizing a flash lamp with a rela-
tively high voltage of about 10,000V could be taken into
consideration, but the flash lamp would then emit a rela-
tively large amount of Uv light whereby toxic ozone would
be generated.
As pointed out, the label web to be imprinted
is usually present in the form of a roll. Such a wide
label web is usually provided with several label imprints
arranged side-by-side (utilization) while being fed
through the continuous-web~label laser printer.
This requires that the imPrinted label web sub-
sequently has to be fed to a cutting station which cuts
the wide label web into strips corresponding in width to
the width of the printed rows. lt is, of course, also
possible to utilize only narrow label webs which carry
only a single row of labels which would eliminate the
need for a cutting station required for multiPle row ap-
plications. However with such an arrangement, the rela-
tively exPensive continuous-web~label laser Printer would
be insufficientlY utilized and the label printing Process
would require a relatively large amount of time. It is
accordinglY a further object of the invention to
intensively utilize the continuous-web/label laser
printer by parallel label printing without however re-
quiring the use of a separate cutting unit.
The obiectives presented, that is:
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4 Case T87
1. easY transport, easy use and easy
servicing of the continuous-web~label laser
printer,
2. suitable arrangement for the fix-
ing station so as to facilitate rapid and effi-
cient printing of a wide variety of materials
from very thin Paper to heat sensitive,
scratch-alkaline-acid-UV-light resistant Plas-
tic and metal foils,
3. multiple utilization of a wide
label web without the requirement for cutting
in an additional operational step,
4. provide a compact transportable
continuous-web~label laser printer which, if
necessary, maY be used as a desk unit,
are solved in accordance with the invention by providing
a toner-fixing station with a flash lamp emitting im-
pulses having an imPulse frequency of 1-5 Hz in the in-
frared light range with an electric energy of about 1500
Ws/impulse corresponding to an adjustable energy densitY
of up to 20 Ws~cm2 which is not in contact with the label
web and to which power is supPlied by a high frequencY
charging unit whose flash condenser achieves a flash
voltage of about 650V, wherein an essentially paraboli-
cally shaped reflector with a radiation opening of about
30 mm as measured in the direction, in which the web ex-
tends is arranged above the flash lamp, wherein cooling
equipment is Provided capable of cooling the flashlight
with about 20 l~s of cooling air and also suction equiP-
ment for drawing off the toner vapors and discharging thevapors through filterst wherein between the fixing sta-
tion (flash lamp) and the winding structure a longitudi-
nal cutting arrangement is provided and wherein the wind-
ing structure consists of a pluralitY of rollers sepa-
rated by discs but oPerated by a common drive.
Consequently, in contrast to the knowncontinuous-web~label laser printers which utilize a hot
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Case T87
fixing drum for heating the toner on the material to be
imprinted and pressing it onto the material to be im-
printed, a flash lamp i5 utilized which operates in the
range between light and infrared, that is, between '00 nm
and 1100 nm and which consequently melts and fixes the
toner on the material to be imPrinted. The succession of
pulses is so selected that the areas irradiated by the
flash lamp overlap so that all of the material to be im-
Printed, that is, all the toner on any of the labels dis-
posed anywhere on the label support web, is safely fixed.Of course, a plurality of flash lamps may be used if the
radiation energy of a single such flash lamp or its geo-
metric dimensions are not adequate for the particular
material to be imprinted. The use of such flash lamps
for the fixing of the toner is basicallY known but it has
not been practiced because problems regarding volume and
practical accommodation of the complete fixing station
with air filter made the construction of a comPact appa-
ratus impossible. Since however, as in the present case,
that is, in connection with the imprinting of adhesive-
coated labels, the advantages of such a flash lamp, which
also has a long life, are evident the present invention
provides for a way to effectively use a flash lamp with
all its advantages--ParticularlY no touching of the let-
tering material and minimal thermal exposure of the mate-
rial to be imprinted and of the adhesive layer--without
encountering its disadvantages. It is pointed out that
the presently known fixing stations of such laser
printers oPerating with flash lamps such as shown, for
30 example, in DE-A-2638658 are oPerating at such a low
energy level that the label taPe has to move only very
slowly in order to insure Proper melting and fixing of
the toner so that the apparatus will not operate effi-
ciently. The energy densitY utilized so far in connec-
tion with such flash lamPs is between 0.8 to maximally 3
Ws~cm2, which, in addition, requires the use of a
special, expensive toner. It is also noted that with
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6 Case T87
such a low energy density--depending on the support web
material--the web is not sufficientlY heated so that,
with these known apparatus, a molten toner crust is
formed on the cold surface of the support web which is
easily removable. However, particularly for labels,
permanent fixing of the images applied thereto is of
course important. On the other hand these small, compact
apparatus should be operable from a normal office elec-
tric power outlet. The Power removable from such an
electric power outlet is accordingly limited such that
the high energy consumption of a flash, if taken directly
from an outlet, would lead to the blowing of the particu-
lar circuit fuse. This Problem is solved in accordance
with the invention by providing, as indicated, a high
frequency power supply apparatus which withdraws from the
power suPply net a constant amount of energy over time,
that is, which avoids the undesirable supply power peaks
that lead to the blowing of the fuse. It is further
noted that, with a flash lamP operating voltage of about
650V, hardly any UV radiation and consequentlY hardly any
objectionable ozone is generated. The heat generated
with the high energy density of uP to 20 Ws~cm2 is
removed with the high suction power of about 20 l~s
together with the toner vapors and eventually the ozone
generated in the vicinity of the flash lamP. In addition
to the protection of the flash lamp from contamination by
toner vapor deposits, this has the advantage that the va-
pors are retained in the filters so that the operating
personnel suffer no exposure. Suitably, the filter
structure includes a dust filter as a preliminary filter
with a subsequent black carbon filter. The formation of
ozone may also be reduced or eliminated if, in accordance
with the invention, the glass of the flash lamP is, at
the same time, a UV light filter.
With such a high flash lamP outPUt, the con-
denser associated with the flash lamp is also heated to a
high degree. In accordance with the invention overheat-
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7 Case T87
ing is avoided bY dividing the flash condenser into a
pluralitY of single condensers arranged in Parallel which
of course are better able to transfer heat to the envi-
ronment, that is, the cooling air.
The use--in accordance with the invention--of a
flash lamp in combination with the cooling and air re-
moval according to the invention additionallY has the ad-
vantage that all the laser printer components can be ar-
ranged in the upper part of a housing together with the
flash lamp whereas the label web is supported in the base
Port of this housing. For inserting the label web into
the continuous-web~label laser printer according to the
invention it is therefore onlY necessary to PiVot the uP-
per part of the housing to the back, to insert the label
web and then to pivot the upper housing part back onto
the housing base and lock it. The housing base further
receives the remainder of the electronic/electrical
equipment as well as the suction equipment with filter
and carries, on opposite sides, the roller guides for the
label web. If, in accordance with a further feature of
the invention, the upper housing part is pivotally
mounted on the housing base by pivot hinges having an
axis extending parallel to the longitudinal direction of
the label web, not only insertion of the label web is
much facilitated as mentioned earlier, but all the comPO-
nents are easily accessible for operation and servicing
without obstructions by any equipment parts. Particu-
larly, no hot fixing drain is in the waY during insertion
of the label web. Generally, the various components of
the apparatus should be disposed in the upper housing
part or in the housing base wherein the upper housing
part is pivotally mounted on the housing base by PiVot
hinges having an axis parallel or normal to the longitu-
dinal direction, and arranged in the guide plane, of the
label web.
Concerning the multiple advantages to be
achieved bY the continuous-web~label laser printer ac-
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8 Case T87
cording to the invention, a lnngitudinal cutting apPara-
tus is arranged ahead of the take-up reel station. The
longitudinal cutting apparatus preferably includes disc
cutters which are disposed on a drive shaft so as to be
movable and lockable thereon, the drive shaft being con-
nected to a drive motor via a magnetic clutch. Such lon-
gitudinal cutting apparatus are known in principle, but
it has not been possible so far to combine both appara-
tus--continuous-web/label laser printer and cutting aPPa-
ratus--together in a single apparatus in such a manner
that the requirement for a comPact, easily operable and
serviceable apparatus was fulfilled. As a result of the
arrangement of the various comPonents of the continuous-
web~label laser printer in accordance with the invention
it has become possible to dispose the cutting apparatus
between the fixing station and the take-up reel such
that, all together, a very comPact, Yet easily service-
able aPParatus is provided.
The drawings schematically show an embodiment
of the invention, that is:
Fig. 1 shows in a front view and
Fig. 2 in a top view the arrangement of the
various components;
Fig. 3 is a side view of the continuous-
web~label laser Printer housing: and
Fig. 4 shows a control arrangement.
From a roll ~1) a wide label support web (2) ispulled out in the direction of the arrow (3) and, at the
oPPOsite end, is again taken up by a take-uP reel struc-
ture (4). An electronic laser control (5) and a flashlamp (6) are disposed above the label web (2). Both com-
ponents--electronic laser control with associated print
transfer drum and the flash lamp--are disposed in an up-
per housing part (7) which maY be pivoted onto a housing
base (9) about an axis (8) (shown in Fig. 1 as dash-
dotted line) which is parallel to the longitudinal
direction of the label web (2). Between the flash lamp
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9 Case T87
(6) and the take-up reel structure (4) several disc
cutters (10) are arranged which cut the wide label web
into narrow strips (2a, 2b, 2c) of a desired width,
whereupon these strips are taken uP bY aPProPriately
sized reels.
Similar to Fig. 1, Fig. 4 shows some more de-
tails of the apparatus. Shown is the label web (2) which
is pulled through the apparatus by means of a friction
drive (11) via a drive motor with impulse generator (12).
Arranged above the label tape (2) is an image transmis-
sion drum (13) which has its upper surface exposed to a
laser beam and which transmits the laser generated image
from its lower side to the label web (2). The length D
on the circumference of the image transmission drum (13)
from the exPOsure to the laser beam to the point of image
transmission onto the label web corresponds to the dis-
tance D in front of the image transmission drum (13)
where a light barrier (14) consisting of an emitter (15)
and a receiver (16) is arranged. Emitter ~15) and re-
ceiver (16) of this light barrier are mounted on pivotarms such that the emitter (15) may be pivoted upwardly
for insertion of the label web (2) and then again re-
turned to its oPerating position. The flash lamP (6)
with reflector ~17) is also arranged above the label web
~2). The image transmission drum (13) as well as the
flash lamp (6) with its reflector are arranged in the up-
per housing part (7). The drive motor (12) as well as
additional electronic and electric devices, that is, the
charging unit L and the control device ST, are received
in the housing base (9).
This, all together provides for a comPact unit
which can be fed on one side with a wide label web for
multiple utilization and from which, at the other side,
rolls of desired width can be taken out which paper rolls
are provided with very accurately represented freely se-
lectable inscriptions while the possibility of Pivoting
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Case T87
the upper housing part open facilitates operation and
servicing.
