Patent Application
20070114366
The invention relates generally to optical articles. More particularly, the invention relates to a multi-component structure employed in optical articles as an anti-theft feature and methods of making same.
Shoplifting is a major problem for retail venues and especially for shopping malls, where it is relatively difficult to keep an eye on each customer while he/she shops or moves around in the store. Relatively small objects, such as CDs and DVDs are easy targets as they can be easily hidden and carried out of the store without getting noticed. Stores, as well as the entertainment industry, incur monetary losses because of such instances. Due to the sensitive nature of the information stored inside, this problem become more severe if the CDs or DVDs are stolen from places like offices.
Even though close circuit surveillance cameras may be located at such places, shoplifting or stealing still occurs. Consumable products sometimes are equipped with theft-deterrent packaging. For example, clothing, CDs, audio tapes, DVDs and other high-value items sometimes are packaged along with tags that set off an alarm if the item is removed from the store without being purchased. These tags are engineered to detect and alert for shoplifting. For example, tags that are commonly used to secure against shoplifting are the Sensormatic® electronic article surveillance (EAS) tags based on acousto-magnetic technology. RFID tags are also employed to trace the items in store shelves and warehouses. Other theft-deteltent technologies currently used for optical discs include special hub caps for DVD packaging that lock down the DVD and prevent it from being removed from the packaging until the DVD is purchased. Similarly, “keepers” that are attached to the outside of the DVD packaging also prevent the opening of the packaging until the DVD is purchased. In some cases, retailers have resorted to storing merchandise in locked glass display cases. In other stores, the DVD cases on the shelves are empty, and the buyer receives the actual disc when the movie is purchased. Many of these approaches are unappealing in that they add an additional inconvenience to the buyer or storeowner or they are not as effective at preventing theft as desired. Optical articles, in particular, pose an additional problem in that they are very easy to remove from their packaging and the sensor/anti-theft tags may be removed easily.
FIGS. 4 and 5 are cross-sectional views of the multi-component structure employing a radio frequency circuitry at two different locations in accordance with exemplary embodiments of the invention.
Embodiments of the invention are directed to an optical article having an anti-theft feature and a method for inhibiting theft of the same.
One exemplary embodiment of the invention is a multi-component structure capable of being removably attached to a plastic element. The multi-component structure includes an adhesive layer having a selectively modifiable tack strength at pre-determined locations on a first surface of the adhesive layer. The first surface is coupled to the plastic element to define a first region. The multi-component structure further includes a backing layer coupled to the adhesive layer to define a second region with a second surface of the adhesive layer. Upon interaction with an external stimulus the multi-component structure is configured to undergo a clean adhesive failure at the first region between the adhesive layer and the plastic element.
Another exemplary embodiment of the invention is an optical article configured to transform from a pre-activated state of functionality to an activated state of functionality. The optical article includes an optical data device for storing data. The data is read from an optical data layer in an activated state of functionality. The optical article further includes the multi-component structure.
Another exemplary embodiment of the invention is a method for selling an optical article. The method includes receiving an optical article and conducting a monetary transaction at a first location. The optical article includes an optical data layer configured to store data and a multi-component structure coupled to the optical article. The multi-component structure is configured to enable a change of functionality of the optical article from a pre-activated state to an activated state.
Another embodiment of the invention is a method for altering functionality of a plastic element from a pre-activated state to an activated state. The method includes providing a plastic element having a multi-component structure coupled to a surface of the plastic element and exposing the plastic element to an external stimulus to change a locus of failure of the multi-component structure.
These and other advantages and features will be more readily understood from the following detailed description of preferred embodiments of the invention that is provided in connection with the accompanying drawings.
In certain embodiments, a multi-component structure is removably coupled to a plastic element. The multi-component structure may be configured to act as an anti-theft feature to inhibit the theft or unauthorized use of the plastic element such as an optical article. In the case where the optical article is a CD or a DVD, the multi-component structure is opaque to the incident laser or otherwise interferes with readout in a pre-activated state. As used herein, the term “pre-activated state” of functionality refers to a state of functionality of the optical article where the multi-component structure has not yet been exposed to one or more external stimulus as will be described in the various embodiments of the invention. In the pre-activated state, the optical article is not readable, that is, in the pre-activated state at least a portion the data on the optical data layer may not be read. In an exemplary embodiment, some or all of the portions of the optical data layer may not be read by the incident laser in the pre-activated state. For example, the multi-component structure may alter the optical property of the optical data layer in certain portions and make the data in these portions unaccessible to the incident laser. In embodiments where the data in some portions of the optical data layer is unreadable, the optical article when played in the player may result in undesirable noise or disturbances when an attempt is made to read the data from these unreadable portions, while the other portions may be read without disturbances.
Contrary to the pre-activated state, the “activated state” of functionality of the optical article refers to the state where the optical article has been exposed to one or more external stimulus as will be described with regard to various embodiments of the invention. In the activated state of functionality, the data in the optical data layer is readable. In other words, the optical article may be read without any noise or disturbances/errors, which may otherwise have been present in the pre-activated state.
The multi-component structure may be coupled to a portion of the plastic element by using an adhesive layer in the multi-component structure. Further, the adhesive layer is coupled to a backing layer. The adhesive layer may include a plurality of individual adhesive layers, which form a stack generally referred to as the adhesive layer. Similarly, the backing layer may include a plurality of individual layers, which form a stack generally referred to as the backing layer. The adhesive layer includes a first surface and a second surface. The first surface of the adhesive layer includes a selectively modifiable tack strength at pre-determined locations. As used herein, the term “selectively modifiable” refers to the ability of the adhesive layer to modify the strength of the adhesive bond. The adhesive layer may have uniform tack strength throughout. Alternatively, the adhesive layer may have variable tack strength, that is, the adhesive layer may have different tack strength at different portions of the first surface. For example, the adhesive layer may have certain portions that have higher tack strength as compared to other portions at the interface defined by the first surface. As used herein, tack strength refers to “stickiness” of the adhesive layer. The tack strength is a measurement of the strength of adhesion, typically measured using standard peel tests and reported in units of pounds-force per inch.
The first surface of the adhesive layer is coupled to the plastic element to define a first region. The second surface of the adhesive layer is coupled to the backing layer to define a second region. When the multi-component structure is de-coupled from the plastic element after interaction with an external stimulus, the multi-component structure undergoes a clean adhesive failure at the first region between the adhesive layer and the plastic element, thereby leaving no significant residue of the adhesive layer on the plastic element upon removal of the multi-component structure as seen by naked eyes. As used herein, the term “clean adhesive failure” or “clean failure” or “clean fracture” or “cleanly removed” or “clean removal” is defined as the removal of the multi-component structure from the plastic element such that no significant residue of the adhesive layer is left behind on the plastic element and the plastic element is therefore useable. For example, in embodiments where the plastic element is an optical article, “clean removal” of the multi-component structure post activation means that any minimal residue of the adhesive layer which might be left behind on the surface of the optical article, even if the adhesive residue is colored, is small enough in quantity so as to not interfere with the readability of the optical article. Whereas, when the multi-component structure is decoupled from the plastic element in the pre-activated state, that is, when the multi-component structure is decoupled from the plastic element without authorized interaction of the multi-component structure with the external stimulus, the multi-component structure undergoes a failure at the regions other than the first region. For example, in the pre-activated state the multi-component structure may undergo a failure at the second region, or a cohesive failure within the adhesive layer. The failure at regions other than the first region are not clean failures, and leave at least a portion of the multi-component structure coupled to the plastic element (e.g. adhesive residue). As will be described in detail below, this left over portion of the multi-component structure renders the plastic element unusable.
Upon exposure to the external stimulus, the multi-component structure undergoes a reduction in the adhesive bond strength at the first surface from a first adhesive bond strength in a range of at least about 1 pound-force per inch to a second adhesive bond strength of about 0 pound-force per inch up to about 1 pound-force per inch upon activation. The decrease in adhesive bond strength between the plastic element and the multi-component structure facilitates clean adhesive failure of the adhesive bond at the first surface in the activated state.
Non-limiting examples of the plastic element may include elements comprising polycarbonates, polyethylenes, polypropylenes, polyesters, polyimides, polysulfones, polyethylene terapthalate, polyamides, polyacrylates, polyurethanes, or copolymer or combinations thereof. In an exemplary embodiment, the plastic element may include an optical article. As used herein, the term “optical article” refers to an article that includes an optical data layer for storing data. The stored data may be read by, for example, an incident laser. The optical article may include one or more layers. Further, the optical article may be protected by employing a protective outer coating. The protective outer coating is transparent to the incident laser, that is, the protective outer coating allows the incident laser to pass through and reach the optical data layer.
The optical article may be an optical storage medium, such as a compact disc (CD), a digital versatile disc (DVD), multi-layer structures, such as DVD-5 or DVD-9, multi-sided structures, such as DVD-10 or DVD-18, a high definition digital versatile disc (HD-DVD), a Blu-ray disc, a near field optical storage disc, a holographic storage medium, or another like volumetric optical storage medium, such as, for example, two-photon or multi-photon absorption storage format. As will be described in detail below, if the optical article is taken out of its packaging without being authorized, or if the optical article is attempted to be played without being authorized, the multi-component structure may render the article unreadable.
In other embodiments, the optical article may also include an identification card, a passport, a payment card, a driver's license, a personal information card, or other plastic or plastic coated security documents, all of which employ an optical data layer for data storage. As will be described in detail below, in these embodiments, the multi-component structure renders the article unreadable by the reader until it is processed prior to being issued to the concerned authority. Hence, if the article is stolen before being issued, the data in the optical data layer is not readable and therefore the article is prevented from any unauthorized use before issuance.
As will be described in detail below, the multi-component structure may be in operative association with one or more devices, such that the devices may receive energy from the external stimulus in one form and convert it into another form. The converted form of energy is then transferred to the adhesive layer of the multi-component structure to change the state of functionality of the optical article. For example, the multi-component structure may be in operative association with radio frequency (RF) circuitry, which may react with an external stimulus, such as radio frequency waves, and convert it into electrical energy and/or thermal energy. The thermal energy may then be utilized by the adhesive layer to change the functionality of the optical article from the pre-activated state to the activated state. Further, the RF circuitry may include a programmable logic chip, such as in a radio frequency identification (RFID) tag. Upon exposure to the appropriate RF radiation, the RF circuitry employing, for example, a heater chip, is energized and converts the RF radiation into thermal energy. This conversion of RF energy into thermal energy creates a temperature spike of about 50° C. to about 200° C. and locally heats a specific area of the multi-component structure. In another example, one or more microheaters may be employed to heat the adhesive layer. The microheaters may be employed to heat the entire adhesive layer. Alternatively, the microheaters may be employed to heat the portions of the adhesive layer having relatively higher tack strength.
In certain embodiments, the multi-component structure may be employed to change the functionality of the optical article. The change in functionality may appear as a result of change in optical properties. The change in optical properties of the optical article can appear in any manner that results in the optical data reader system detecting a substantial change. For example, where the adhesive layer comprises a colored dye additive material, which is partially or completely opaque to a pre-determined wavelength of the optical data reader system, if the multi-component structure is removed from the optical article prior to activation thus leaving a colored residue of the adhesive layer on the surface of the optical article, there should be a significant change (e.g. reduction) in the amount of incident radiation detected as a result of selective absorption or reflection by the colored dye additive at one or more given wavelengths of interest (corresponding to the type of electronic storage device data reader system energy source). However, energy absorbance by the adhesive layer material is not the only way to effect an optical property change.
In certain embodiments, the multi-component structure may render an optical state change from the pre-activated state to the activated state. The optical change may include a change in an optical property, such as reflectivity, single layer reflectivity, dual layer reflectivity, refractive index. The multi-component structure may render the optical article partially or completely unreadable in the pre-activated state of functionality of the optical article. In the pre-activated state, the multi-component structure may act as a read-inhibit device by inhibiting the laser from reaching at least a portion of the optical data layer and reading the data on the optical data layer. For example, the multi-component structure may absorb or reflect a significant portion of the incident laser, thereby impeding it from reaching the optical data layer to read the data. If an attempt to remove the multi-component structure (e.g. peel off) from the optical article in the pre-activated state, any portion of the adhesive layer which is left on the surface of the optical article (e.g. a residue) may inhibit the laser from reaching at least a portion of the optical article.
Alternatively, the multi-component structure may render the optical article partially or completely unreadable in the pre-activated state of functionality due to the optical article being unbalanced, or otherwise have an altered mechanical property that inhibits the optical article from spinning at the correct speed within the optical drive. The multi-component structure may also prevent the optical article from physically loading into the optical drive or reader. For example, in embodiments where the optical article is a CD or a DVD, it is envisioned that the multi-component structure is disposed across the center hole of the disk (e.g. across the hub portion of the disk) thereby preventing the disk from being physically loaded into the disk-drive if the disk is in the pre-activated state. Upon removal of the multi-component structure after activation, the optical article has the appropriate mechanical properties to be loaded, spun, and read without error in the optical drive.
In an exemplary embodiment, the optical article may be made of a polycarbonate. As used herein, the term “polycarbonate” refers to both aliphatic and aromatic polycarbonates, and any co-polymers of polycarbonates incorporating structural units derived from one or more dihydroxy compounds. For example, aromatic polycarbonates marketed under the trade names LEXAN® or MAKROLON® are suitable polycarbonates.
Upon interaction with one or more external stimuli, the locus of failure of the multi-component structure is altered to change the functionality of the optical article from the pre-activated state to the activated state. As used herein, the term “locus of failure” means the physical location at which an adhesive bond breaks or fractures. For example, in the pre-activated state, the multi-component structure may be configured to have locus of failure at the second region, that is, at the interface between the adhesive layer and the backing layer. Alternatively, in the pre-activated state, the failure may also occur within the adhesive layer, which is sometimes referred to as cohesive failure. As will be described in detail with regard to
The external stimulus may include a laser, infrared radiation, thermal energy, infrared rays, X-rays, gamma rays, microwaves, visible light, ultraviolet light, ultrasound waves, radio frequency waves, microwaves, electrical energy, chemical energy, magnetic energy, mechanical energy, or combinations thereof. Furthermore, inter-conversion between any of the above listed external stimuli (e.g. conversion of radio frequency energy first to electrical energy, and then optionally to thermal energy) is also included within the scope of this invention. The interaction of the external stimulus with the multi-component structure may include continuous, discontinuous, or pulsed forms of the external stimulus. Furthermore, the activation may be done by using a wireless stimulus (i.e. heat or electromagnetic radiation of appropriate power and wavelength such as radio waves) at the point of sale (POS) of the plastic element, which will deliver the appropriate amount of energy needed to the optical article to which the multi-component structure is disposed.
The adhesive layer may include a material having reversibly or irreversibly modifiable tack strength, that is, once altered, the tack strength may or may not be modifiable back to the initial tack strength. In one embodiment, the change from the pre-activated state to the activated state is irreversible. The decrease in tack strength at the first surface or region of the adhesive layer may be induced by a variety of mechanisms including, but not limited to, a chemical mechanism, an electrochemical mechanism, a thermal mechanism, a physical mechanism, a cross linking mechanism, or any combination thereof.
The adhesive layer may include one or more pressure sensitive adhesives materials. In at least one embodiment, the pressure sensitive adhesive is crosslinkable, that is, the pressure sensitive adhesive includes crosslinkable functionality. For example, suitable materials may include acrylate-based polymers, which contain crosslinkable functionalities. In one embodiment, the adhesive layer may include an acrylate based material that contains a glycidyl acrylate functionality, an epoxide functionality, an aziridine functionality, an ester functionality, an anhydride functionality, a carbonate functionality, or any other crosslinking functionality commonly known to one skilled in the art of polymer crosslinking.
In one embodiment the adhesive layer comprises an additive, which can induce a change in tack strength at the first surface or region of the adhesive layer. The additive may be an organic additive or an inorganic additive. For example, in one embodiment the adhesive layer comprises an expandable microsphere additive, which is designed to undergo an increase in volume when heated. Suitable microspheres include such as those marketed under the name of Expancel® Microspheres by Akzo Nobel, or those present in the dicing tapes marketed by the Nitto Denko Corporation under the trade names REVALPHA®.
The backing layer may be made of any flexible material, including but not limited to a plastic material. In one embodiment the backing material contains functionality that is capable of forming covalent bonds with the adhesive layer upon activation. The backing layer can be made of a polymeric material with a glass transition temperature (Tg) greater than about 150° C. Alternatively, the backing layer may be made of a crystalline polymer having a melting point above about 180° C. Suitable example of the backing layer material may include polycarbonates, polyethylenes, polyesters, polyimides, polysulfones, polyethylene terapthalate, polyamides, polyacrylates, polyurethanes, or copolymer or combinations thereof.
In one embodiment, the adhesive layer may include a colored dye additive material, which can absorb radiation in the visible portion of the electromagnetic spectrum (e.g. radiation with a wavelength from about 300 nm to about 900 nm), and interfere with the laser from reaching the optical data layer in the pre-activated state. In another embodiment, the material of the adhesive layer may include a convertible material that changes optical property in response to the external stimulus. For example, the material of the adhesive layer may include one or more of a color-shift dye, a photo-chromic material, a magnetic material, an electrochromic material, or a thermochromic material, a magneto-optical material, a photorefractive material, a light scattering material, a phase-change material, dye aggregates, nanoparticles, expandable microspheres, or combinations thereof. The color-shift dye may refer to a material, which may change from a first color to a second color upon interaction with an external stimulus, such that the first color, second color, or both are transparent to the incident laser. In some embodiments, the color-shift dye may include a bleachable dye, which absorbs radiation in the visible portion of the electromagnetic spectrum (e.g. radiation with a wavelength from about 300 nm to about 900 nm), but which bleaches upon interaction with the external stimulus, thereby becoming transparent to radiation in the visible portion of the electromagnetic spectrum. In one embodiment, the color-shift dye may darken upon interaction with the external stimulus, thereby absorbing the incident laser light. In another embodiment, the color-shift dye may lighten upon interaction with the external stimulus, thereby becoming transparent to the incident laser light. In yet other embodiment, the color-shift dye may include an aryl carbonium dye, thiozine, spyropyran, fulgide, diarylethene, liquid crystal, leuco dye, a hydroquinone based compound, a pH sensitive dye, a lactone dye (e.g. crystal violet lactone) or any other suitable dye chemical compounds known by one skilled in dye art. These dyes may be mixed with the adhesive material of the adhesive layer.
Furthermore, the color-shift dye, such as a photo-bleachable dye, may also be interacted with ultraviolet (UV) light. The wavelength of the UV light may be in a range from about 190 nm to about 400 nm. It should be appreciated that the wavelength of the incident laser, (i.e., the laser light used to read the optical article is about 780 nm for a CD, about 650 nm for a DVD, about 405 nm for an HD-DVD or a Blu-ray). Hence, the optical article having the photo-bleachable dye may be unreadable in pre-activated state, but becomes readable upon interaction with the external stimulus for activating the optical article. UV light may also be used when the dye is combined with photo catalytic additives, such as titania nanoparticles. Suitable but non-limiting examples include methylene blue, polymethine dye, or malachite green. These dyes may be exposed to UV light individually or in combination with activators such as titania nanoparticles. These additives may absorb the external stimulus. In an exemplary embodiment, this absorption of the external stimulus by the additives may result in temperature change of the additives. This temperature change may cause local heating of the adhesive layer thereby changing one or more properties of the adhesive layer (e.g. the tack strength of the adhesive layer) and/or affecting the color-shift dye if one is present in the adhesive layer.
The external stimulus may be selected based on the kind of material of the adhesive layer including a color-shift dye and other additives within the adhesive layer. Herein, the other additives may include organic or inorganic additives in combination with the color-shift dye. For example, the external stimulus may be thermal energy and the temperature of the thermal energy may be based upon the crosslinking rate of a polymer in the adhesive layer. In another example, when the adhesive layer includes a color-shift dye, the external stimulus may be a light source of appropriate wavelength and power to make the color-shift dye transparent to the laser, thereby changing the functionality of the optical article from an un-readable state to a readable state.
Referring now to
The adhesive layer 14 may be disposed on the backing layer 22 in various forms. For example, the adhesive layer 14 may either be in the form of a continuous layer extending over the entire backing layer 22. Alternatively, the adhesive layer 14 may be a patterned layer, which may or may not extend over the entire backing layer 22. Additionally, although not illustrated, the optical article may employ two or more multi-component structures 10 disposed in discreet portions of the optical article 12.
The backing layer 22 in turn may comprise radio frequency circuitry (not shown) to receive, convert, and transfer the required energy to the adhesive layer 14 and/or the backing layer 22 as will be described in detail with regard to
In one embodiment, the adhesive tack strength at the first region 20 (adhesive layer/optical article) may be reduced (e.g. from high tack strength to low tack strength) by changing the modulus of the adhesive layer 14 by crosslinking the adhesive layer, which contains materials that possess cross linkable functionalities (e.g. epoxides, aziridines, acrylates) either in the backbone of the adhesive polymer system or simply in the adhesive formulation. Upon activation at the POS, the material in the adhesive layer 14 may undergo crosslinking after being subjected to the external stimulus, thereby increasing the modulus (e.g. stiffening) of the adhesive layer 14 and decreasing the adhesion forces or tack (i.e. detackifying) at the first region 20. At the same time, if the backing layer 22 comprises sufficient functionality that can react with the crosslinking mechanism taking place in the adhesive layer 14, then upon activation, the second region 24 (interface defined by adhesive layer/backing layer) may be strengthened by forming covalent bonds across the second region 24. Therefore, upon activation, crosslinking may simultaneously decreases the strength of adhesion at the first region 20 and increases the strength of adhesion at the second region 24, thereby allowing the multi-component structure 10 to be cleanly removed from the optical article 12 and thus render the optical article 12 playable after activation. In one embodiment, in the pre-activated state the tack strength at the optical article/adhesive layer region may be at least about 1 pound-force per inch. In one embodiment, in the activated state the tack strength at the optical article/adhesive layer region may be in a range of from about 0 pound-force per inch to about 1 pound-force per inch.
FIGS. 4 to 7 illustrate alternate embodiments of the multi-component structure 10 of
Turning now to
Referring now to
With reference to
The optical storage medium 50 further includes multi-component structure 56 disposed across the hub region 54. Alternatively, when disposed in or across the inner hub 54, the multi-component structure 56 may either be restricted only to the inner hub 54 or may extend out from the inner hub 54 onto the data storage region 52. Additionally, the multi-component structure 56 may be disposed in different locations in the data storage region 52 surrounding the inner hub 54. The portions 57 of the multi-component structure 56 having the adhesive layer are coupled to the medium 50, whereas the central portion 59 of the multi-component structure 56 is disposed above the hub region and may not necessarily be in direct contact with the medium 50. In an exemplary embodiment, the central portion 59 may include an antenna (not shown) for the radio frequency circuitry. The antenna interacts with the RF energy and transfers the energy to the radio frequency circuitry. The multi-component structure 56 may include any of the multi-component structures 10, 28, 44 of the previously depicted embodiments.
Further, the optical storage medium 50 may include one or more of the multi-component structure 56. The multi-component structure 56 may alter the state of functionality of the optical storage medium 50 as described above with regard to
In alternate embodiments, the multi-component structure of the present technique may be employed in other optical articles, such as an identification (ID) card.
As noted above, the material of the adhesive layer 70 may contain a colored dye additive (e.g. a material which absorbs light in the visible portion of the spectrum, 300 nm-900 nm) and may be configured to change its color to become transparent to the incident laser upon activation. However, in the activated state, after interaction with the external stimulus, the multi-component structure 68 may be peeled off along with the adhesive layer 70, thereby allowing an incident laser to pass through and reach the optical data layer 62 and allowing the reader to read the data stored in the optical data layer 62 of the card 60. The ID card 60 may be exposed to the external stimulus before issuing the ID card 60 to the concerned authority, thereby rendering the data in the optical data layer 62 readable by the incident laser. By protecting the data in this manner before issuance of the ID card 60 to the concerned authority, the undesirable use of the card may be prevented in the event the card is stolen from the location where the card was stored prior to issuance.
Referring now to
At block 98, the optical article is authorized for use, that is, the state of functionality of the optical article is changed from a pre-activated state to the activated state at a location, such as point-of-sale. Accordingly, if the optical article is taken without a proper transaction being conducted, the optical article will not be readable. The authorization of the optical article may be done in several ways at the authorization location. For example, the optical article may be authorized by exposing the optical article to an external stimulus having a predetermined power and emitting an energy of predetermined wavelength range by placing the optical article with or without the packaging in proximity to an external stimulus.
Further, the source for external stimulus may be built in the point of sale equipment. As used herein, the term “point of sale equipment” refers to equipment employed at the point in the shop where the sale takes place. For example, the point of sale equipment includes a bar code reader, a radio frequency identification reader, an electronic surveillance article reader, like an acousto-magnetic tag detector or de-activator, such that when the optical article or the packaging having the optical article is swiped through the bar code reader, the multi-component structure is allowed to interact with the external stimulus and the state of the optical article is converted to the activated state. Further, the source of the external stimulus may also be integrated with a hand-held wand or computer controlled boxes at the aisles. It is desirable to have sources that have a power and/or wavelength of the energy which is not commonly available, specifically to defaulting users, such as shoplifters.
Additionally, the verification of the activation may be conducted on the optical article. The verification may be desirable either to: 1) identify the defaulting users, or 2) to confirm that the optical article was accurately activated at the first point of interaction, such as a point-of-sale. In some embodiments the verification may be conducted at the second location, such as the exit point of the storage location in office premises, or a store. In these embodiments, the security system installed at the exit locations may send out signals indicating whether or not the optical article is activated. Further, a device may be installed in the security system, such that the device may interact with the multi-component structure in the optical article and make it permanently unreadable if the optical article was carried out without being activated.
A 1-inch by 2-inch multilayer adhesive label is affixed to a DVD by first removing the liner from the tape and pressing the adhesive layer against the read-side of a DVD. After a few hours, the adhesion of the adhesive is tested by peeling the tape away from the disc. It is found that the tape could not easily be removed from the disc. Another labeled DVD is prepared in a similar fashion using another adhesive label affixed to the disc. However, this sample is exposed to a RF source in the frequency range of about 100 KHz to about 2.5 GHz. An inductively coupled antenna located in/on the backing of the label converts the RF energy to an electric voltage. This voltage powers a micro heater located on/in the backing of the label. The micro heater locally heats the adhesive above its activation temperature of about 100° C. to about 120° C. for several seconds to reduce the adhesive strength of the adhesive layer.
A 5-inch long by 0.5-inch wide strip of a commercially available adhesive tape typically composed of an adhesive layer deposited on a backing layer (e.g. either a UV-activable tape form Semicorp Equipment Corporation (SEC), or a thermally-activatable tape from Nitto-Denko Corporation, was affixed to a 5-inch long by 0.5-inch wide by 0.125-inch thick piece of optical grade polycarbonate (e.g., General Electric LEXAN®) by pressing the adhesive layer evenly against the polycarbonate plastic with approximately 60 PSI of force at 50-75 degrees Celsius for 1 hour. After 1 hour, the samples were cooled to room temperature, and for a first batch of samples the strength of the adhesive bond between the tape and the polycarbonate plastic was measured using an Instron extensometer, following the protocol for a 90 degree peel test according ASTM method 6862. Peel strengths were measured at 1, 5, and 25-inches/minute peel rates. Samples from a second batch, which were prepared as described above, were further subjected to an activation step prior to peel testing. For example, the activation step was either exposure to intense UV radiation using a UV lamp obtained from Xenon Corporation or an additional heating step. Results are listed in the table below.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
The present patent application is a continuation-in-part application from U.S. patent application Ser. No. 11/286,413, filed Nov. 21, 2005, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11286413 | Nov 2005 | US |
| Child | 11536199 | Sep 2006 | US |
