This invention relates to the partial printing of a substrate with a plurality of layers to form a partially printed panel. Within each printed portion, at least one layer is applied to the substrate with inexact registration in relation to a second layer. A “control layer” comprising “edge sealing strips” is printed so that, within each printed portion, each edge of the at least two layers with inexact registration is located within the edges of an overlapping edge sealing strip. The edge sealing strips may provide a visual seal or mask at the edges of printed portions, for example to enable the each printed portion to have the desired color rendering that would otherwise not be consistently achieved through lack of registration. There are many other applications for the invention, for example to control any other incident wave characteristics of the partially printed panel, for example its solar radiation transmission, absorption and reflection characteristics. The invention can enable the physical sealing of printed portions containing gaseous or liquid fluids or particles in suspension, such as fragrances, or to produce printed portions to contain medication, for example skin patches with improved medication transfer control. Other applications of the invention include security printing, security labels, security seals and environmentally reactive labels, for example labels indicating the temperature regime to which a labeled product has been subjected.
There are a number of visual and other functional benefits in printing only part of the area of a substrate, some of which are outlined in GB 2 118 096 (Hill & Yule), GB 2 165 292 (Hill), PCT/GB98/02600 (Hill) and PCT/GB97/00020 (Hill).
Methods of partially printing a substrate with substantially exact registration of superimposed layers are outlined in GB 2 118 096, GB 2 165 292, GB 2 188 873, PCT/GB96/02600, PCT/GB97/02788 (Hill and Godden) and PCT/IB00/00267 (Hill and Clare). However, these methods typically involve the use of special inks and additional production stages compared to the simple deposition of layers of ink or other marking material. Partially printed substrates can typically be produced more economically by conventional methods of printing having inexact registration, providing any undesirable effects of such lack of registration can be consistently overcome.
PCT/GB96/02600 discloses why conventional printing processes all suffer inexact registration, owing to:
With regard to those figures illustrating a cross-section through a single printed portion on a substrate 10, it should be understood that the single printed portion is typically representative of a plurality of such printed portions on a cross-section through substrate 10.
Depending on the method of printing, the equipment used, the operator's skills, the disciplines introduced to control registration, the type of substrate, the size of the area being printed and the direction of application of ink, for example the direction of a squeegee pull in screen printing, the reliably achievable registration tolerance will vary. However, for any given printing set-up, it is possible to establish a reliably achievable registration tolerance “T” in a given direction in relation to the direction of application of ink. It is typically desirable to produce products according to GB 2 188 873GB 2 165 292 according to the “Lateral Combination Method” or “Through Combination Method” of PCT/GB96/02600 with printed portions in a pattern of lines oriented in the direction of application of ink. This is because the registration tolerance “T” is less perpendicular to the lines than the registration tolerance “T+ΔT” in the direction of application of ink. Thus, in screen printing, lines would typically be oriented in the direction of squeegee pull; in litho printing the lines would be orientated parallel to the direction of travel of the substrate through the machine.
GB 2 188 873GB 2 165 292 identifies in “Overlap Method 1” that a design visible from one side of a panel can be obscured from visibility from the other side of a panel by the simple expedient of one layer, typically a black silhouette pattern layer according to that invention, overlapping other layers, typically one or more white background layers and one or more design color layers.
The prior art “Lateral Combination Method” of PCT/GB96/02600 illustrated in
The prior art “Through Combination Method” of PCT/GB96/02600 illustrated in notional cross-section
However, in the production of such panels, in order to achieve the required opacity of a white background layer 30, it has been found necessary to print several layers of white or to introduce one or more layers of silver in between the white and the black layers, both well known prior art methods of improving the perceived whiteness and opacity of a white layer. A notional arrangement of
According to the present invention a panel comprises a substantially imperforate substrate and a print pattern adhered to said substrate, said print pattern being printed onto only part of said substrate and comprising at least three layers including a first layer, a second layer, and a control layer, said first layer, said second layer, and said control layer being configured and disposed such that a cross-section taken through said panel comprises two outer edges of said substrate and alternate printed portions of said substrate and unprinted portions of said substrate, each said printed portion having two outer edges, and wherein within said cross-section of said panel each of a plurality of said printed portions being constructed and arranged such that they each include a part of said first layer and a part of said second layer and a part of said control layer, said plurality of said printed portions each including two outer edges of said part of said first layer and two outer edges of said part of said second layer and two outer edges of said part of said control layer, and wherein within each of said plurality of said printed portions said part of said second layer is located between said part of said first layer and said part of said control layer, and wherein the width between said two outer edges of each of said plurality of said printed portions is less than one centimeter, and wherein said part of said control layer comprises two edge sealing strips and each of said two edge sealing strips comprises one of said two outer edges of said part of said control layer and an inner edge, and wherein one of said two outer edges of said part of said first layer and one of said two outer edges of said part of said second layer are positioned within said outer and inner edges of one of said two edge sealing strips and the other of said two outer edges of said part of said first layer and the other of said two outer edges of said part of said second layer are positioned within said outer and inner edges of the outer of said two edge sealing strips.
In the notional arrangement of
In the following descriptions of the figures, the layers applied to a substrate are sometimes described in absolute terms, such as first layer, second layer, another layer, base layer and control layer, but in order that the invention is more readily understood and to more easily recognize the improvements of the invention over the prior art, the various layers are sometimes described in similar terms to the prior art vision control panel constructions over which the invention has particular advantages. Thus, white layer 30 is an example of a first layer 30 and may be of any color or other feature. Design color layer 40 is an example of a second layer 40 and may be of any color or other feature. Design color layer 40 may be a multi-color process layer, for example a four color process layer in which the deposits of individual colors, typically cyan, magenta, yellow and black are discontinuous and there may be no deposit of ink within a part of such a layer, the width between the outer edges of part of a multi-color process layer in a printed portion being deemed to be the same as the width between the outer edges of the white layer 30 in the same printed portion. Black layer 50 is an example of a base layer 50 and may be of any color or other feature. Silver layer 70 is an example of another layer 70 and may be of any color or other feature. Transparent substrate 10 is an example of substrate 10 and may have any substrate characteristics. The form of construction and arrangement of any printed portion described in terms of color layers should be understood to disclose the illustrated relationships of the various layers of any materials for any product for any purpose.
The printed portions can be of identical construction in the number and thickness of layers, cross-sectioned dimensions, etc., or may vary across a panel. First layer 30 typically extends across the full control width 100 within every printed portion of a cross-section through a panel, as may second layer 40, as illustrated in FIG. 8E. Alternatively, second layer 40 can be discontinuous, for example layer 40 might be a multi-color printing process, in which each individual color, for example cyan, magenta, yellow and black is typically discontinuous, typically in the form of a half-tone or stochastic pattern. Second layer 40 can comprise one or more ‘spot’ or ‘line’ uniform colors which form a recognizable design. In
In
The prior art Through Combination Method has a disadvantage compared to the prior exact registration printing methods in that the perceived color width is less than the width of the silhouette pattern printed portions by the width of the overlapping black edges, typically arranged to be 4T on each side, as illustrated in FIG. 5A. In an example arrangement of the Through Combination Method, in which T is 0.075 mm, black lines of 2.4 mm width are printed at 3 mm centers, superimposed by white lines of 1.8 mm width and design color lines of 2.1 mm width, the “perceived color width” is the width of the white layer, being 1.8 mm, which provides an effective “design impact” of 60% of the panel area, compared to a silhouette pattern area of 80% of the panel area, the difference of 20% being of no value in “design impact” or visibility through the panel from the opposite side. With the present invention, for example according to
It is commonly desired in the printing of such panels to utilize a multi-colour printing process, for example the conventional “CMYK” four color printing process, in which “half-tone” dots or stochastic patterns of cyan [C], magenta [M], yellow [Y] and black [K] are printed to achieve the desired color rendering in each part of the printed panel. The CMYK colors, even the black, are typically not opaque but translucent. When superimposed on a white background layer, the eye perceives the combination of the individual color layers and the white background layer, rather than the individual CMYK colors. From a typical observation distance the eye and brain cannot resolve the individual dots. Because the CMYK ink layers are translucent, each underlying layer has a visual effect, even when viewed through an overlying layer. It is conventional to print such layers on a white background in the order CMYK. The technique of undercover removal (UCR) is used, for example to economize on the use of ink. Where an opaque black is desired, it is common to arrange for other color layers to lie beneath the black layer, for example a 50% half tone of cyan, in order to perceive a more opaque black. However, producing panels according to GB 2 165 292, for example, the edge sealing strips may be part of the black K layer in a CMYK process printed design. An independent control layer of edge sealing strips is not required. In
Thus, with the edge sealing strip method of the present invention, any number of layers of ink or other material can be superimposed of substantially the same cross-sectional width and be edge sealed, for example to mask and thus control the visual effects of lack of registration. It is possible to obtain the combined or interactive effect of any number of superimposed layers, for example silver, white and design color layers, with absolute consistency over the full control width, unlike the prior art methods of managing such lack of registration. Any desired hue, intensity and greytone can be achieved between the edge sealing strips, unlike the “Lateral Combination Method,” which always exposes edge strips of white, requiring color manipulation procedures to achieved desired perceived colors and not being capable of accommodating very dark colors, including black.
Unlike the “Through Combination Method,” the design color layer 40 inks need not be translucent but can be of any degree of opacity, and any number and type of layers under the control layer can be incorporated, as the controlling feature of color consistency is the gap between the edge sealing strips on each printed portion, two further major advantages of the present invention over the prior art.
The printed layers have thus far been shown printed on one side of a substrate. However, especially with transparent substrates, there are advantages in printing one or more layers on one side of a substrate and other layers on the other side of the substrate. If the substrate is thin, for example a thin transparent film of say 100 micron thickness, the small potential for parallax error can be masked by a suitably chosen overlap of the edge sealing strips.
In
Panels of the invention, typically comprising a transparent substrate, may have one control layer on one side of each printed portion and another control layer on the other side of each printed portion. For example,
In the context of this invention, a substrate means any sheet or film material which may include any number of layers of surface coating. A transparent substrate allows an observer on one side of the substrate to focus on an object spaced from the other side of the substrate. A translucent material is one that allows light to pass through it.
Any layer of material applied to the substrate may be a multiple layer, for example the edge sealing strips may comprise two or more layers of ink or other material.
The invention includes many different embodiments and the figures are examples of these and not exhaustive. Features of one illustrated construction may be considered in conjunction with features from another figure, for example the arrangement of edge sealing in one figure may be considered in conjunction with the underlying or overlying layers from another figure.
The layers described as black layer, white layer and design color layer may comprise any color including black and white, the figures being primarily intended to disclose different constructional arrangements which enable the edge sealing of at least two layers, the outer edges of which lie within the edges of an overlying or underlying edge sealing strip.
Where reference is made in the figures or text dimensions in terms of T or a multiple of T, T is the reliably achievable registration tolerance or maximum registration error that is likely to result from a particular printing set-up, in a given direction, for example the line of a cross-section illustrated. The dimensional disclosures in terms of T are intended to enable one skilled in the art to reliably make panels according to the invention and such dimensional disclosures are not limitative any way, the invention essentially concerning the positioning of the respective layers in relation to their outer edges and, in the case of a control layer, the outer and inner edges of the edge sealing strips on a particular printed portion. The invention is not dependent on any particular quantitative dimensions. However, the invention is of most value to panels in which the cross-sectional widths of individual printed portions are small, typically less than 1 cm, more typically less than 5 mm and as small as 1 mm. The negative consequences of normal lack of registration and consequently the benefits of the invention are typically greater the smaller the cross-sectional width of any printed portion.
While the figures typically illustrate a plurality of superimposed layers that are edge sealed of notionally the same width, the width of any layer need not be the same as the width of any other layer in any particular cross-section through any printed portion.
Retro-reflective inks may be incorporated into panels of the invention in a number of ways. For example, in any of the
Any printed portion that is illustrated in any of the figures or is a combination of illustrated features in any of the figures can form part of a panel with a cross-section having a plurality of printed portions in which design color layer 40 extends across each control width 100, in the manner of
The invention can be printed by any conventional printing process, including screen-printing, litho printing, gravure printing and any type of digital printing, including ink jet, electrostatic, electrostatic transfer and thermal transfer printing.
The invention may be manufactured by printing onto a substrate which forms part of a finished product. However, it is also possible to practice the invention on a decal paper or other transfer medium, from which the individual printed portions are transferred to the ultimately desired substrate. For example, a transfer medium can be electrostatically printed with cured liquid or powder toner, which is then transferred by a laminating machine to a substrate, for example a transparent PVC film, to form a panel of the invention. As another example, the invention may be practiced on conventional ceramic ink decal paper, the printed ink decal portions being subsequently transferred to a sheet of glass, then typically fused into the sheet of glass to form the desired end product.
Panels of the invention such as those in
In vision control panels, edge sealing strips need not necessarily provide a “dead” visual area. For example, prior art one-way vision squash court walls are partially printed transparent substrates, typically comprising a black layer superimposed by a uniform white or other uniform colored layer, the black layer to provide good through vision for spectators and TV cameras and the relatively light layer to provide good visibility of the wall surface for players and a background against which to sight the squash ball. The development of such one-way vision materials has instigated the use in tournaments of a white squash ball in conjunction with colored background walls, instead of the traditional black squash ball and white walls, principally because a white squash ball is more visible on television. The color should not be too light, in order to provide adequate contrast with a white squash ball. Dual-tone or other multi-colored designs have also been introduced for such one-way vision squash court walls, primarily in order to enhance wall visibility. The present invention allows a consistent arrangement of exposed color layer surrounded on each printed portion by a consistent edge sealing strip, whereas the prior art methods of trying to print layers of identical geometry by conventional means or the Lateral Combination Method or the Through Combination Method will all reveal the lack of registration in the layers of individual printed portions when closely observed. Any revealed black edges will vary in thickness from point to point on such prior art panels and, in some cases, will not be visible. With the present invention, the individual edge sealing strips, typically black combined with a light design color layer in small printed portions, are not resolved by the eye of the player or spectator, resulting in the desired mixed perceived color, as well as a uniformly patterned, attractive surface when seen at close quarters. This benefit of uniform appearance of panels will apply to all types of vision control panel subject to close inspection, for example architectural privacy glazing or decorative partitions. The inevitable lack of registration of the underlying layers is masked by the uniform edge sealing strip which overlaps all other edges and forms the ‘framing’ of each printed portion.
It will be appreciated that the invention is completely different to the prior art method of ‘trapping’ with an outline, typically a black outline, the edges of abutting areas of color or the edges of four superimposed CMYK color process layers in a conventional design, for example a cartoon figure with black outlines to different color areas on a white paper substrate. In the prior art, these trapping lines follow the edges of colored areas of a design which together typically form a continuum of ink or design, rather than the partially printed portions on the substrate of the present invention. The prior art black outlines are clearly visible, indeed form a dominant feature of the overall design, for example assisting the brain to more quickly translate a two-dimensional representation into a readily perceived three dimensional object. With the present invention, the edge sealing strips, whether black or other color, do not follow the outline or internal color variations in a design but simply frame each printed portion. However, the edge sealing strips typically form a regular arrangement of quite thick lines in the foreground of visibility, unlike the underlying black edges of the prior art Lateral Combination Method and Through Combination Method and would be expected to form an easily recognizable pattern. Surprisingly, the brain is attracted to the design which is superimposed on the printed processes, not the edge sealing strips on the individual printed portions. An explanation of this surprising phenomenon may possibly be found in the field of perception, known academically as the psychology of cognitive science and neutral function, that the eye is a sensory organ and the brain interprets the resulting stimuli to make sense of these stimuli. For example, if a design is a simple two-dimensional drawing of a cube or box, this appears to be a three-dimensional cube because individuals have had extensive experience with real boxes and can interpret the three-dimensional “cues” leading to this understanding of the drawn object. Also, the most fundamental step in the complex dynamics of form perception is the almost effortless perceptual phenomenon that certain parts of any differentiated visual field stand out in a distinctive manner from other parts, known as figure-ground differentiation. In the prior art, the outline forms a dominant part of the figure, whereas in the present invention the edge sealing strips surrounding the print pattern, which may be as thick or thicker than prior art outlines, are unexpectedly not perceived but form part of the ground or background. The eye is not attracted to the edge sealing strips but to the superimposed design or color(s) they surround.
Separately, prior art outlines trap the edges of abutting layers or discontinuous superimposed multi-colore process layers, typically half-tone or stochastic discontinuous layers, whereas the present invention seals or masks the edges of at least two superimposed layers, at least one of which is continuous across each control width 100 of each printed portion in a cross-section through the panel. Additionally, there is typically no need in the prior art printing to incorporate underlying, white, silver or black layers that are not visible outside a printed design color layer.
Furthermore, in the prior art of outlines, there is no need to carefully control the dimensions of partially printed portions and thereby unprinted portions in order to control various aspects of panel performance, including the perceived color. The prior art outlines are simply to ‘clean up’ color zone edges and/or highlight features of a design to assist the brain's perception of the prior art design. Such prior art devices are still appropriate for designs incorporated into panels of the present invention, but such outlines would not follow the edges of the print pattern but would typically lie inside printed portions, following the external edges and possibly internal boundaries of the design, for example between different color zones. With panels of the present invention incorporating a design, an observer typically does not focus on the edge sealing portions because the brain is concentrating on more dominant stimuli. If the observer progressively moves away from the panel, there will come a point when the individual portions of the print pattern and edge sealing strips will no longer be capable of resolution but the design or second layer will still be visible.
Also, surprisingly, the introduction of the exposed edge sealing strips of a particular color, typically black, different to an exposed design color layer within the printed portions, enables rather than compromises the perception of the required design color.
Besides vision control panels, the present invention can be used for many other types of partially printed panels. Panels may be used to control the absorption and/or reflection of energy waves outside the visible spectrum. The invention may be used to modify the environmental properties of a panel. Glazing materials such as glass commonly have solar shading and solar reflection characteristics built into their construction, for example by the printing of a ceramic ink pattern or by the deposition of one or more metallic layers by “sputtering.” Panels according to GB 2 165 292 are commonly used not only for their vision control performance but also for solar control in reducing solar glare, heat gain and UV radiation. According to the invention, layers can be applied to optimize on the desired reflection and/or absorption capabilities of partially printed portions of such panels. Glazing or other panels may contain electrically conductive layers, for example as heating elements or for electro-luminescent effects. The present invention allows multiple layers to be printed with inexact registration and be edge sealed, to provide consistent desired performance and appearance.
The invention can be used to control of the emission or absorption of gases, liquids or particles in suspension, such as fragrances. In such applications, the edge sealing strips may comprise actual physical fluid seals rather than just masks to visual or other forms of wave energy. Fluids may be deposited into one or more absorbed layers, the edge sealing strips retaining the fluid from sideways percolation and leakage prior to the application of a capping seal to each individual edge sealing strips or the panel as a whole. The capping seal can be printed, for example by using a cured fluid such as plastisol ink, self-adhesive film or otherwise applied film, the exposed top of the printed portions being a compatible material to assist such effective sealing. Overall capping seals can be perforated or otherwise pre-weakened in lines between individual printed portions to allow subsequent exposure of individual printed portions. In prior art so-called scratch ‘n’ sniff products fragrances may be released by a scratch-removable printed layer. The invention enables the individual removal of seals for fragrances, providing a more “up-market” solution than the prior art scratch‘n’sniff products. In
The rate of diffusion of a fluid from an edge sealed layer through one or more covering layers is dependent mainly upon the properties of the one of more covering layers, in particular the void ratio, the form of the voids and the frictional or drag characteristics of the solid surfaces surrounding the voids. Inks typically comprise pigments, fillers and a matrix which, whether solvent or water based, will typically leave a percentage of voids in a cured ink. The solid fillers may be evenly “graded”, in the same way that stone hardcore in roads may be graded, such that small solids fill the spaces between larger solids, or may be “gap-graded” to deliberately leave voids of the required range of size, for example to allow the desired passage of fluids. By controlling the nature, the permeability, the thickness and number of such layers, accurate control can be achieved over the rate of diffusion of a fluid from a printed portion, for example after a sealing layer has been removed. As illustrated in
Printing is a very efficient production method, for example for producing medications, especially if such medication is arranged in an array with printed instructions, for example identifying the desired day and timing of such medication. Prior art pills need separate packaging and printed instructions to provide such information.
The invention's variable multi-layer technology enables timed release of medication, using a uniform medication, rather than the differing components in prior art pills to provide for timed release of medication. The manufacturer of the medication is simplified and more economic.
Panels comprising ink with gap-graded pigments and/or filters exposed on the surface have an additional advantage of providing a degree of sound absorbency, which can be advantageous for such hard, sound-reflective surfaces such as glass.
GB 2 188 873 (Hill) discloses methods of exact registration printing and several improvements of security printing, security seals and security labels, including methods in which one or more layers of information are masked by one or more other layers. According to the present invention, edge sealing strips may be used to prevent the number or nature of superimposed layers being established by microscopic or other inspection of the exposed edges of the superimposed layers.
Another prior art security device is for a removable printed layer to obscure another printed layer, for example a scratch-removable ink layer obscuring lottery or other numbers or indication on a “scratch card.” It is known that the purpose of such scratch cards as a lottery device can be fraudulently abused by an “inside operator” removing the scratch-removable ink, observing the disclosed information and reprinting scratchable ink over those scratch cards that are not “winners.” Edge sealing strips 95 may be applied to scratch-removable layer such that it cannot be so easily fraudulently replaced after removal. While scratchable ink is typically a commodity material, typically colored silver, the edge sealing strips can be of virtually any type of ink and color and therefore the selection of the edge sealing ink provides an additional security device against the fraudulent exposure and subsequent recovering of lottery tickets. The edge sealing strips 95 also highlight and provide an attractive framing to the areas of interest in such lottery cards.
In another embodiment of the invention, layers of material may be visually masked in a uniformly perceived manner but change their characteristics according to ambient or historical temperature regimes, for example as used in measures to protect the safety of food. In
Such products may require an array of partially printed elements, for example which have layers that change color at different temperatures, or the invention may be used to produce elements in large quantity that are used independently of each other, for example individually printed portions used for temperature indication labels or to monitor x-rays received by the printed portion, for example when applied to a product or the skin or clothing of an individual.
A base layer 50 of a printed portion may be applied to a release surface of substrate 10 or applied to substrate 10, to enable the easy removal of individual printed portions. Such printed portions may be edible and comprise medication, for example a pill substitute, or a candy or sweet confectionery substitute, releasing a flavor at the desired rate, which can be healthier than prior art products, which are typically high in sugar and other undesirable contents.
The edge sealing strips may comprise adhesive material, for example pressure-sensitive or heat activated adhesive, to enable the printed panel to be sealed. Alternatively, the material selected for the edge sealing strips may be chosen to act as a good seal with a self-adhesive overlaminate or heat-activated sealing film. Panels may be adhered to another base material, for example vision control panels of the present invention also according to GB 2165292 or PCT/GB97/00020, produced on film materials, may be adhered to a window without affecting the optical clarity of the transparent substrate areas which are not printed. The prior art adhesive means of securing such films to windows, for example by an overall layer of pressure-sensitive adhesive between the applied film and the window, cause a reduction in clarity of through vision. The edge sealing strips may be resilient, thereby enabling each printed portion to act as a suction pad. For example, if a flexible film comprising such printed portions is “squeegeed” against a window, air is expelled from the gap between the compressible edge of each sealing strip the printed portion and the window. Upon release, after squeegeeing, the resulting partial vacuum in each printed portion causes effective adhesion of each printed portion to the window and thereby the adhesion of the overall applied film. Edge sealing strips comprising plastisol ink, for example, enable such suction pad performance of the individual printed portions.
If the control layers is exposed on the surface of a panel, the edge sealing strips project from the layer of ink beneath it, thereby providing a degree of protection against abrasion to the ink layers beneath the edge sealing strips. For example, panels of the present invention applied outside the window of a vehicle are more durable under the abrasion of automatic window wiper blades than the prior art methods in which the design forms the outer layer and is directly subject to abrasion.
In summary, the invention has very wide application within a range of partially printed products in which it is required to obscure or otherwise control the inevitable lack of registration in the production of such products.
Number | Name | Date | Kind |
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4321778 | Whitehead | Mar 1982 | A |
4925705 | Hill | May 1990 | A |
5281499 | Bussard | Jan 1994 | A |
5830529 | Ross | Nov 1998 | A |
6210776 | Hill | Apr 2001 | B1 |
6212805 | Hill | Apr 2001 | B1 |
RE37186 | Hill | May 2001 | E |
6267052 | Hill et al. | Jul 2001 | B1 |
6506475 | Hill | Jan 2003 | B1 |
6507413 | Mueller | Jan 2003 | B1 |
Number | Date | Country |
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212 3437 | Feb 1972 | DE |
008 5732 | Aug 1983 | EP |
2 118 096 | Apr 1986 | GB |
2 188 873 | Oct 1987 | GB |
14101 | Jan 1982 | JP |
WO 9747481 | Dec 1997 | WO |
WO 0046043 | Aug 2000 | WO |
Number | Date | Country | |
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Parent | 09764276 | Jan 2001 | US |
Child | 11034445 | US |