EP1202238A1

EP1202238A1 - Micro engraving indicia

Info

Publication number: EP1202238A1
Application number: EP00123778A
Authority: EP
Inventors: Stanislas Steenbrugge
Original assignee: Brady Worldwide Inc
Current assignee: Brady Worldwide Inc
Priority date: 2000-10-31
Filing date: 2000-10-31
Publication date: 2002-05-02

Abstract

An adhesive label (1) for application to a product such as a cellular telephone or electronic device, wherein the label provides both conventional printed material and laser printed indicia for verification of source or manufacture. This label may provide an encoded laser printed digital, alphanumeric, or graphical pattern, said pattern not being readily apparent, by which the manufacturer may be verified. Such labels comprise a transparent substrate (2), a layer of laser imprintable material, and an adhesive layer (5) by which the label may be adhered to a product.

Description

BACKGROUND OF THE INVENTION

This invention relates to a method for the application of a marking, or indicia, to a substrate, specifically a substrate such as a label to be adhered to an article of manufacture. The invention is particularly directed to a method for creating an unobvious or invisible code on a label for inventory control and prevention of counterfeiting. The code employed may be created by a low-power industrial laser, before, during, or after printing of visible matter on the label, and while not obvious or readily noticeable, may be easily read with low power magnification.
Large numbers of items such as cellular telephones, CD players, cameras, pagers, hand-held computers and personal assistants, etc., are produced each year. There is a flourishing trade in the manufacture and sale of counterfeit units bearing the trade dress and name of well known products. In addition to the articles themselves, there are a large variety of accessories, such as batteries, cases, chargers, car kits, etc, which are also subject to such counterfeiting. Much money is spent on an annual basis in combating such illegal endeavors.
It has been suggested that one means to assist in this battle is to provide the manufacturer with a readily verifiable marking, which marking is not obvious to the eye, and which may be encoded so as to be readily changed as necessary or desired. It is to be noted that in the past, when attempts were made to provide distinctive labeling or marking of products, the counterfeiters were able to readily copy and counterfeit the markings themselves. For this reason, it is desired to provide a marking which is not readily visible, and which may be readily changed at the manufacturer's option. For example, a manufacturer may learn of certain counterfeiting activity relative to only one line of products, and may change the markings affixed to that product, i.e. modify a line of code embedded in the label, and simultaneously notify the appropriate distribution or customs officials of the change. These officials, having received the new code for the product, could then delay for further inspection, or verification of source, any product in shipment not having the "correct" code engraved in the label.
As will be readily understood, those engaged in counterfeiting activity are quite diligent in their approach to business, changing the counterfeit product to correspond to the genuine product as quickly as possible, including all labeling thereof, so as to maintain their position in the market. Accordingly, it is desirable that markings or indicia included by the manufacturer or his licensees are subtle and unobvious, and moreover, not easily duplicated. Moreover, it is highly desirable that any such markings or indicia occupy a minimal area on the package labeling, thus taking up the least possible amount of territory on the product.
One of the problems with markings or indicia presently applied by label to a product is that they are both easily detected and easily duplicated. For example, those labels bearing printed information, whether encoded or not, may be readily duplicated by the counterfeiters, as evidenced by the many fraudulent packages, such as "jewel boxes" containing bogus software or CDs, or unlicenced copies of CDs, which are sold world wide to the unsuspecting public.
Various methods have been developed for preparing labels containing confidential or encoded information, including various conventional techniques for printing on adhesive labels. U.S. patent number 5,571,587, relative to sheet stock for use in laser and ink jet printers, discloses the use of metalized polyester films as a top sheet for printing. Such a material is suitable for use in the present invention, although the reference does not suggest the manner in which it might be employed in the present invention.
In US patent number 5,142,327, of Kahle, a photo receptor belt is taught, comprising an aluminized polyester film substrate coated with an organic or inorganic photoconductive material. Niefert et al, in U.S. patents 5,868,074 and 5,931,097, teach laser imageable printing members, comprising laser ablative metalized substrates. In these patents, a method is taught for preparation of lithographic members, wherein a polymeric film substrate is coated with a vacuum deposited laser ablative thin film layer of a metal such as titanium, zirconium, aluminum, or hafnium. This ablative layer is then over-coated with an organic material layer to provide a direct-write film, the organic material layer being chosen to have hydrophilic, hydrophobic, or oleophobic characteristics with respect to the printing inks to be used therewith. The printing film is imaged by lasers to create images on the composite film due to ablation mechanisms resulting from gasification of the organic layer, which causes ejection of the overlying laser energy absorbing layer. Thus, the ablative laser energy absorbing coating is not melted or vaporized, which is indicated as being a known technique, but altered by the heating of the underlying substrate to create an image in response to laser discharge. The polymeric film substrate to which the metal film layer is applied may be adhered to a backing sheet or substrate. However, the goal, purpose, and direction of the references are to provide a printing medium, as opposed to a readable print label as in the present invention.
Thus, while it is known that ablatable metallic coatings may be imaged by a laser, no one to date has suggested direct printing upon a metalized substrate to create a label for a commercial product. Thus, a simplified and inexpensive technique is desired for the provision of a label to be applied to a substrate, such as a commercial product, wherein said label includes a laser printed encoded indicia, information, or number for verification of source.

SUMMARY OF THE INVENTION

The present invention provides an adhesive label for application to a product, the label bearing in addition to conventional printed information, a laser imprinted dot code, alphanumeric designation, or other indicia, which may be read under amplification, but which is not readily apparent to the eye of the untrained observer.
It is thus an advantage of the present invention to provide a non-obvious encoded label which may not be readily counterfeited, and which may be verified by the appropriate individuals as being indicative of the source of the product to which the label is adhered.
It is yet another advantage of the present invention that such a label may be readily changed, as necessary or desired, on a regular schedule or at random, so as to further ensure confidentiality of the information necessary to verify the source of the product so labeled.
It is thus an advantage of the present invention to provide an inexpensive method for application of an identification label to a product to more positively identify the source thereof, and is a still further advantage to provide such a label which can be inexpensively manufactured.
These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, appended claims and accompanying drawings

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A is a cross-sectional view of a label made in accordance with the present invention.
Figure 1B is an enlarged view of the area of Figure 1A indicated by line 1B-1B.
Figure 2 is a top view showing the label of the present invention.
Figure 2A is an enlargement of the area of Figure 2 indicated by line 2A-2A.
Figure 3 is a simplified schematic of a printhead suitable for use in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Metalized polymeric sheet materials are well known, and the use of metalized polyester or other polymeric sheet materials for adhesive labels is known. In the past, information has been printed upon such label materials in a number of conventional ways. One such method has been the use of a conventional printer, such as provides a 600dpi (dots per inch) print capability. Such a high print capability is useful for deterring counterfeit labeling, and may provide clear and minutely detailed imaging on a printed label. An additional technique which is becoming popular due to relative effectiveness is the imprinting of holograms upon a metalized label which is affixed to the product, although counterfeiters have recently become adept at duplication of such holograms.
The present invention takes this label printing capability to a still further level, by incorporating a laser printed encoded indicia or code in a metal layer in the label to indicate the source or manufacturer. It has been found that the localized or isolated and controlled application of heat from a laser to the metalized coating, through a transparent substrate such as polyester, may produce small, non-reflective spots or ablated regions, and especially that localized heating of an aluminized coating can oxidize the coating into a non-reflective (and thus almost transparent) region. By appropriate control of the pattern of exposure, e.g. by computerized control of the laser, a code may be generated on the aluminized surface of the label, which code may be of the size and configuration desired, and which can be read through the transparent film which covers the metallic coating when the label is adhered to a substrate. When an aluminized coating is oxidized to a transparent state, the background color of the substrate to which the label is adhered will show through the label. Such a code may be a series of dots, i.e. a digital code, which may be computer readable, or an alphanumeric form. Such a technique may be employed in conjunction with conventionally applied information printed on the label, such as with a bar code printed on the surface of the polyester substrate.
As shown in Figures 1A and magnified view 1B, a label is provided comprising transparent polymer base material, a metalized layer, an adhesive layer, and an over-lying liner. As shown in the figure, the metalized layer may be subject to engraving by means of a laser beam, to produce a pit, an ablated area, or an area of differing composition and visual property. In a preferred embodiment of the invention, heat from a laser is applied to an aluminized substrate of polyester, thereby producing small, non-reflective spots, as a result of the localized heating of the aluminum coating causing oxidation thereof to an non-reflective (and thus almost transparent) region.
In Figures 1A and 1B, a label, 1, of the present invention is illustrated in cross section. Polymeric substrate 2 has coated on one side thereof a metallic layer, 3. Such metalized polymeric substrates are available commercially, in the form of coated films, such as Camvac International 2.0 mil metalized Polyester, or from other manufacturers of metalized film. The metallic coating is then over coated with an adhesive layer 5, which is in turn covered by a peelable film or release liner, 6, to prevent premature adherence of the adhesive to any substrates with which the label may come in contact. The metalized layer may be subjected to laser engraving, which may cause the formation of a void, pit, or a non-reflective local area, 4. Since the adhesive is on the side of the metalized layer opposite the transparent polymeric substrate, the void, pit, or non-reflective area 4 may be seen through the transparent substrate, 2.
The polymeric substrate may be any transparent substrate suitable for the purpose, but is preferably a polyester or polymeric substrate, having a thickness of from about 0.2 to 10 mils, and preferably from about 1 to 2 mils. It is desirable that this substrate have superior dimensional stability, and the use of such materials as polyethyleneterephthalate (PET) is preferred. Other polymeric substrates, such as polyesters, acrylics, polypropylene, or vinyl film may also be used. As will be apparent from the Figures, the polymeric substrate forms the uppermost surface of the label as applied to a product, with the adhesive forming the back thereof. The polymeric material thus serves to protect the metal layer from abrasion and scratching, as well as serving as a carrier therefor. Moreover, the polymeric substrate may be printed by conventional printing means, so as to provide further information relative to the product to which the label is affixed, such as Manufacturer, model number, warranty information, etc.
Applied to the polymeric substrate is a layer of a laser ablative or laser energy absorptive metal. Typically, a single ablative or laser energy absorptive metal layer is deposited. However, additional layers may be used if desired. The deposition may be done by sputtering or thermal vaporization. The vacuum-deposited layer is typically deposited to a thickness ranging from about 5 angstrom units to 400 angstroms, and preferably a thickness of less than about 200 Å. The metal, which may be selected from such metals as aluminum, gold, silver, or alloys thereof, can be vacuum deposited to the desired thickness in a single coating pass, or in multiple passes through a roll coater by resistive heating, electron beam heating, or sputtering of the metal. Aluminum is the preferred metal for the purpose of the present invention, being readily oxidized by a low powered laser beam to aluminum oxide, which becomes essentially transparent against the aluminum metal background, thus providing a visually distinct pattern which may be detected. Preferably, the laser printed pattern is of a small size, which will not be obvious to the untrained or unwary eye, and will not be readily noticed. However, the pattern will be noticeable to those who anticipate its presence, and will be readily seen under low magnification, such as with a 10 to 100 power magnification lens. For example, a series of digital entries may be made, so as to be read as a digital numeral corresponding to information appearing elsewhere, in conventional print, upon the label surface, such as in a bar code printed thereupon.
A conventional adhesive layer may be applied to the side of the metallic layer opposite the polymeric substrate, so as to provide means for application of the label to a product of manufacture. While not critical to the present invention, the adhesive may be any conventional label adhesive, applied in a conventional manner to the side of the label to be attached to the product to be labeled. Preferred adhesives include such pressure sensitive adhesives as acrylics, rubber based, or block copolymer adhesives, applied by such techniques as wire wound rod coating, slot coating, reverse roll application, gravure, or other application methods. The thickness of the adhesive coating should be such as to afford a firm and effective bond to the substrate to which the label is to be affixed, without causing the label to exceed the conventional label thicknesses which are suitable for conventional labeling machines. Correspondingly, the release liner, 6, may be any suitable material, such as a polymeric film or paper, which is non-adherent, or only slightly adherent, to the adhesive, and may be readily removed from the label surface for application of the label to a substrate. Conventional plastic webs or sheet materials are preferred, and may be from 0.1 to about 1.5 mils in thickness.
In Figure 2A, a top view is shown of a pair of labels, 1, in accordance with the present invention. Shown are the labels, located upon a web of label film 14, having conventional printed information thereupon, and a printed "index" line or printed line of information, 8, such as may be applied by a thermal transfer printer, with a laser printed line of information or data, 9, in close proximity thereto. The laser printed line is shown enlarged in Figure 2A, as comprising a digitally encoded series of dots. However, it is equally possible to laser print alphanumeric information, drawings, or configurations of choice, on the metalized surface of the label substrate, as may be preferred by the user. Further, while the laser printed indicia or marking is shown as adjacent the edge of the label, in proximity to a line of conventionally printed information, it is clear that the laser printed marking may be printed at any location on the label, as preferred. While it is a preferred embodiment of the invention that the laser printing is relatively small, requiring magnification to be easily read or interpreted, it is equally possible for the laser printed information to be of any size, configuration, shape, or density desired. It is also to be noted that the face of the label may have imprinted thereupon any information desired, such as the name of the manufacturer, the model designation, warranty information, the serial number of the unit of manufacture, or a bar code employed to designate any or all of this information. It is also possible for the laser printed marking to duplicate or replicate such information or bar code, in much smaller scale, requiring the use of magnification to compare the two sources of information to verify the source of the product. As previously indicated, the laser printed information may include a specified sequence of letters and or numbers as set forth by the manufacturer in confidential communication to those seeking, or responsible for, verification of the authenticity of the product. Such a sequence of letters or numbers could be subject to change at the will of the manufacturer, by virtue of the ability to rapidly change programing of the information printed by the laser in the metalized layer.
Figure 3 represents a simplified schematic of a thermal transfer print head, 12, incorporating a low power laser print device, 13, in accordance with the method of the present invention. Illustrated is a web of label film, 14, in passage through print means 15. The label film, 14, which comprises a polymeric substrate having a metalized layer affixed to the bottom surface thereof, as shown in Figures 1A and 1B, is shown passing above the laser 13, which prints a pattern upon the lower side of the label film, in the metallic layer. The label film 14 is then passed through roll means 16 to a position below the thermal transfer print head, 12, where conventionally printed information is applied to the upper surface of the polymer film. The printed label film, now bearing both laser printed indicia and conventional print information, may then be transferred to conventional coating means for application of adhesive and peelable backing layer to the metalized side of the film, and thence to conventional cutting, stacking, or rolling apparatus for storage prior to use, or directly to a labeling machine for application to the product substrate to which the labels are to be affixed.
It is also possible for the laser print device to be located above the path of the polymeric substrate, and to print through the transparent film. In such an instance, the label film may be pre-printed with the desired conventionally printed information, and "pre-pasted", bearing the adhesive layer below the metalized layer of the label, and after laser printing of the code indicia, may be passed directly to the label cutting and application stage. In fact, it is possible that, with the appropriate label materials, and laser print device, the laser printing of encoded information could be accomplished after the label has been affixed to the product. Such an embodiment would have value in countering counterfeiting, in that it would permit the greatest degree of flexibility and confidentiality relative to the information being encoded on the labels, by permitting last minute adjustment, revision, and correlation to a previously determined encoding scheme, such as to correspond to the serial number of the individual product entity being labeled, or even to a randomly generated numeric pattern. It is also to be noted that such an approach, using combined printer and laser etch devices, will allow extremely tight tolerances between the visible printing and the laser indicia, thus making counterfeiting of the label even more difficult.
The present invention has many advantages. First, it provides means by which goods which are frequently copied or counterfeited may be easily, and economically, protected by means of an additional marking or indicia of authenticity. Second, the marking as provided is neither obvious nor readily duplicated. Thirdly, the manufacturer may alter the marking in accordance with a predetermined pattern, schedule, or course of events, thus making duplication more difficult.
As an example of the present invention, a laser code was imprinted on an adhesive backed metalized polyester label, utilizing a neodymium laser from Rofin Sinar. A computerized control of the laser printer was employed to establish a laser code consisting of a series of dots. Also printed on the label, by conventional thermal transfer printing means, were information relative to the Manufacturer and rating of a device upon which such a label could be utilized. After the label was cut from the web, and adhered to a product, the laser imprinted information was clearly readable with the assistance of a magnifying lens, but not without magnification.
Although the present invention has been described in considerable detail with reference to certain preferred embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the preferred embodiments, which have been presented for purposes of illustration and not of limitation. For example, many other lasers, such as a Phillips OPU Optical Unit 29.25 would be suitable for the present invention. The specific laser and/or printer employed are not critical to the invention, as long as each has the capability to achieve the purposes of the present invention. Further, it should be noted that the laser imprinted indicia need not be applied through the topside of the transparent film, but may, under appropriate circumstances and control, be applied through the bottom of the construction, through the adhesive and a transparent release liner.
Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.

INDUSTRIAL APPLICABILITY

The invention provides a label for industrially manufactured goods, such as electronic devices, which may be applied to the goods at the time of manufacture or subsequently, and may include an indicator or indicia of origin, or other information. The labels of the present invention are imprinted with conventional printed information, and also contain laser imprinted information which is not readily observable without the use of magnification, and may thus be used for verification of authenticity. The labels are prepared with a metalized stock material base, and laser printed with a commercial laser, to embed a desired digital, alphanumeric, or graphic pattern in the metallic layer. By use of computer controlled printing, the embedded information may be carefully selected and controlled so as to correspond to a specific indicia or pattern, and may be changed at the will of the user to combat counterfeiting of commercial goods. The printing apparatus employed for the conventional printing is available commercially, as are suitable laser printing devices, metalized film for use as a stock material, and the various other pieces of equipment necessary to implement the use of the invention.
The subject matter of the application can be summarized as follows:
An adhesive label for application to a product such as a cellular telephone or electronic device, wherein the label provides both conventional printed material and laser printed indicia for verification of source or manufacture. This label may provide an encoded laser printed digital, alphanumeric, or graphical pattern, said pattern not being readily apparent, by which the manufacturer may be verified. Such labels comprise a transparent substrate, a layer of laser imprintable material, and an adhesive layer by which the label may be adhered to a product.

Claims

An adhesive label comprising a film substrate, said film substrate comprising a flexible plastic material having upper and lower surfaces, and having a thickness of from about 0.2 to about 10 mils; a laser energy absorptive coating disposed upon said lower surface of said substrate, said coating comprising a metal layer having a thickness of from about 5 to about 400 angstrom units; and an adhesive layer disposed over the side of said laser energy absorptive layer opposite said film substrate; said label being suitable for application of conventional print material to the upper surface of said film substrate and for laser printing of indicia in said metal layer, said indicia being visible through said film substrate.
An adhesive label comprising a flexible transparent plastic substrate having upper and lower surfaces and a thickness of from about 0.2 to about 10 mils; a metal layer disposed upon said lower surface of said substrate having a thickness of from about 5 to about 400 angstrom units; and an adhesive layer disposed over the side of said metal layer opposite said plastic substrate; said label having conventional print material applied to the upper surface of said plastic substrate and laser printed indicia applied to said metal layer, said indicia being visible through said plastic substrate.
An adhesive label as set forth in Claim 1, wherein said laser printed indicia is not readily apparent to the eye.
An adhesive label as set forth in any preceding claim, wherein said substrate comprises a polymer selected from the group consisting of polyethylene-terapthalate, polyesters, acrylics, polypropylene, and vinyl polymers, and said metal layer comprises a vacuum-deposited metal selected from the group consisting of aluminum, silver, gold, and alloys thereof.
An adhesive label as set forth in any preceding claim, wherein said substrate is polyethyleneterapthalate, and said vacuum-deposited metal comprises aluminum.
An adhesive label as set forth in any preceding claim, further comprising a preferably removable release liner over said adhesive layer.
An adhesive label as set forth in any preceding claim, wherein said laser printed indicia is selected from the group consisting of digital, alphanumeric, and graphic patterns, and is readily readable under magnification.
An adhesive label as set forth in Claim 7 , wherein said laser printed indicia is encoded.
An article of commerce comprising a product having adhered thereto an adhesive label comprising a film substrate, said film substrate comprising a flexible plastic material having upper and lower surfaces, and having a thickness of from about 0.2 to about 10 mils; a laser energy absorptive coating disposed upon said lower surface of said substrate, said coating comprising a metal layer having a thickness of from about 5 to about 400 angstrom units; and an adhesive layer disposed over the side of said laser energy absorptive layer opposite said film substrate and adhering said label to said product; said label being suitable for application of conventional print material to the upper surface of said film substrate and for laser printing of indicia in said metal layer, said indicia being visible through said film substrate.
The article of commerce of claim 9 , wherein said film substrate comprises a polymer selected from the group consisting of polyethylene-terapthalate, polyesters, acrylics, polypropylene, and vinyl polymers, and said metal layer comprises a vacuum-deposited metal selected from the group consisting of aluminum, silver, gold, and alloys thereof.
The article of commerce of Claim 10, wherein said laser printed indicia is not readily apparent to the eye.
The article of commerce of Claim 11, wherein said laser printed indicia is selected from the group consisting of digital, alphanumeric, and graphic patterns, and is readily readable under magnification.
The article of commerce of Claim 12, wherein said laser printed indicia is encoded.