Method for manufacturing a display

Abstract: A system and a method for producing displays such as signs and cards includes a continuous substrate of material (14) which is passed from a supply roller (12) to a take-up roller (16). A series of revolving cylinders (26a-26e) containing ink are positioned to sequentially contact the substrate (14) as the substrate material moves to the take-up roller (16). The surface (28) of each of the cylinders is perforated by a predetermined pattern (30a-30e) of holes. The ink contained in the cylinders moves through the holes in the surface and is applied to the substrate (14) as the cylinder revolves. The patterns laid down by the separate cylinders are thus added to create the final design. The color, nature and visual quality of the ink pattern formed on the substrate may be varied by changing the number of cylinders and the types of ink applied.

Description: The present invention relates generally to the fabrication of printed materials. More specifically, the present invention relates to methods for continuous production of printed displays including signs and cards and their packaging. The present invention is particularly, but not exclusively, useful as a continuous, roll-to-roll, method for producing metalized cards with enhanced highlights. BACKGROUND OF THE INVENTION In the past, the manufacture of displays, such as signs and cards, has generally been performed using a step-by-step, or piecemeal, methodology. Methodologies of this type start with a substrate material upon which a design is to be printed. The substrate is positioned in a printing, or inking station, and a layer of colored ink is applied. The substrate is then moved to a second printing station where a second layer of colored ink is applied. The process of moving the substrate and applying layers of ink is repeated until the desired number of layers have been applied and the design is complete. Often, a so-called four color process is used where layers of red, yellow, blue, and black inks are sequentially applied. Each of the layers consists of a distinct pattern of dots and the complimentary interaction between the differing dot patterns each composed of a separate color results in a full-color image on the substrate surface. Generally, step-by-step methodologies are subject to a number of operational disadvantages. For instance, it may be appreciated that each printing station will experience idle periods while it waits for a new substrate to be loaded. As a result, the manufacturing process is slowed and, consequently, the cost of manufacturing the display is increased. To alleviate this problem, multiple ink printing systems have been developed. These systems allow multiple layers of ink to be applied by the same printing station thereby reducing the number of delays attributable to the process of moving the substrate to successive printing stations. Unfortunately, these systems have proven to be both complex and expensive, limiting the applicability of these systems, especially in cases where production of a low cost product is essential. A second method for increasing the speed and efficiency of traditional printing systems involves the employment of specialized handling equipment for moving the display substrates between the various printing subsystems. Equipment of this type speeds the manufacturing process by decreasing the delays experienced at each printing station while it waits for a new substrate to be loaded. Equipment of this type, however, is expensive to produce and use and must be carefully designed to avoid damage to the printed design as the substrate moves through the manufacturing process. A third method for increasing the speed and efficiency of traditional printing systems involves the use of a larger substrate and replication of the display design to produce multiple designs on a single substrate. At the completion of the printing process, the substrate is partitioned and multiple displays are produced. The technique of replication may also be efficiently employed where multiple designs are desired. In practice, however, the replication technique is inherently limited by the difficulty involved in handling large substrates. In light of the above, it is an object of the present invention to provide a method for manufacturing displays which operates as a continuous and on-going process. It is another object of the present invention to provide a method for manufacturing displays capable of reliably maintaining a high production rate. Yet another object of the present invention is to provide a method for manufacturing displays which functions without the need for expensive or complex handling equipment. Still another object of the present invention is to provide a method for manufacturing displays which is relatively simple to use, is relatively easy to implement and is comparatively cost effective. EP-A-338 378 (American Bank Note Holographics, Inc) relates to methods and apparatus for forming a hologram by casting a surface relief pattern directly onto the sheet material in a limited area, followed by coating with a reflective or refractive material only on the limited area of the sheet where the hologram has been cast. SUMMARY OF THE PREFERRED EMBODIMENTS The present invention provides methods for manufacturing displays as defined in the accompanying claims. To achieve the goals of the present invention, a continuous supply of substrate material is initially wound onto a supply roller. The actual material used as the substrate may vary widely but generally includes various clear and opaque plastics, cardboard and paper types. The substrate material on the supply roller is connected to a take-up roller so that the substrate material may be transferred from the supply roller to the take-up roller by revolving the take-up roller. An electric motor is connected to the take-up roller to provide the required rotation. Between the supply roller and the take-up roller, the substrate passes over a supporting surface which creates a substantially flat, moving, working area. In accordance with the present invention, a number of printing stations are positioned sequentially between the supply roller and the take-up roller over the flat moving surface of the substrate. As the substrate moves between the supply roller and the take-up roller, each of the printing stations deposits a pattern of ink dots onto the substrate. The type of ink pattern applied by each station varies according to the type of design required. For instance, for designs that require a four-color process, four printing stations are positioned to sequentially apply separate patterns of red, blue, yellow and black dots respectively. A more complex design which includes translucent and opaque sections may be produced by applying a four-color design onto a translucent substrate and adding an additional station to apply a layer of opaque ink to selected portions of the substrate. Still more complex designs which feature texturized or multi-dimensional appearances may be produced by adding still more printing stations to apply thick ink layers to selective portions of the substrate such as described in U.S. Patent No 4,933,218 issued to Longobardi. In general, numerous printing technologies may be adapted to implement the functionality required of the printing stations. In practice, however, it has been found to be especially practical to implement the printing stations as cylindrical printing screens containing pressurized ink. Each of the cylindrical screens is positioned to revolvingly contact the substrate as it moves from the supply roller to the take-up roller. Importantly, the revolving contact between the screens and the substrate is maintained so that the tangential velocity of each screen equals the linear velocity of the moving substrate. Additionally, the rotation of each screen is synchronized so that the screens rotate in phase. As the screens revolve, the ink within each screen moves through a pattern of holes in the surface of the screen. The ink is then applied as a patterned layer of ink dots onto the substrate and the combination of ink layers applied by the individual screens forms a printed design on the surface of the substrate. In some cases, it may be necessary to fully or partially cure an ink layer prior to application of any subsequent components. In such cases, the substrate material may be passed through an ultraviolet or heat curing oven after the ink layer requiring curing has been applied. The use of curing ovens is particularly effective when thick, or extraordinarily thick ink layers are applied. Depending on the intended use of the final product, it may be advantageous to add additional substrate layers as cover or backing materials. For instance, it may be desirable to apply a translucent protective layer over the printed design. Alternatively, it may be desirable to apply a metalized backing behind the printed design to produce a flamboyant visual effect. In such cases, the system of the present invention may be modified to include a secondary supply roller for the additional material. The secondary supply roller provides a continuous feed of the additional material which may be laminated to the substrate with the use of heat or pressure sensitive adhesives. The secondary supply roller and laminating means may be positioned at any point between the supply roller and the take-up roller where application of the additional substrate material is desirable. BRIEF DESCRIPTION OF THE DRAWINGS The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: Figure 1 is an isometric view of the apparatus of the present invention; Figure 2 is an isometric view of the rotating screen of the present invention shown with portions removed to reveal the fixed blade of the present invention; Figure 3 is an isometric view of an intaglio roller shown as an embodiment for the printing station of the present invention; Figure 4 is an isometric view of an alternate embodiment of the apparatus of the present invention; Figure 5 is a front elevational view of a display as produced by the present invention; and Figure 6 is a cross-section of the display produced by the present invention as seen along the line 6 - 6 in Figure 5. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a method for manufacturing displays in a continuous, in-line system. The apparatus used in the present invention is shown in Figure 1 and is generally designated 10. The apparatus 10 includes a supply roller 12 onto which a substrate material 14 is wound. The substrate material 14 may be composed of varying materials such as paper or cardboard. In practice, however, it has been found that clear, opaque and translucent plastics are particularly suitable for use as the substrate material 14. The apparatus 10 also includes a take-up roller 16 connected to an electric drive motor 18. The substrate material 14 is connected to the take-up roller 16 so that the revolution of the take-up roller 16, caused by the electric drive motor 18 causes the substrate material 14 to unwind from the supply roller 12 and pass to the take-up roller 16. The direction of movement of the substrate material 14 between the supply roller 12 and the take-up roller 16 is indicated by the arrow 20. A pair of guide rollers 22a and 22b and a supporting surface 24 are located between the supply roller 12 and the take-up roller 16 to provide a flat, moving zone where the substrate material may be manipulated. A series of printing stations 26a, 26b, 26c, 26d, 26e are positioned between the guide rollers 22a and 22b and over the supporting surface 24 to revolvingly contact the moving substrate material 14. Each of the printing stations, 26a, 26b, 26c, 26d, 26e includes a cylindrical rotating screen 28 formed with a pattern (30a, 30b, 30c, 30d, 30e respectively). The rotating motion of each of the rotating screens 28 included in the printing stations 26a, 26b, 26c, 26d, 26e is coordinated so that the tangential velocity of the screen 28 is equivalent to the linear velocity of the moving substrate material 14. Additionally, the rotating motion of each rotating screens 28 included in the printing stations 26a, 26b, 26c, 26d, 26e is synchronized so that each pattern 26a, 26b, 26c, 26d, 26e rotates in phase. It should be appreciated the number of printing stations such as printing station 26a, 26b, 26c, 26d or 26e may be varied to suit the needs of the particular end product desired. The structural details of the printing stations 26a, 26b, 26c, 26d, 26e may be better appreciated by reference to Figure 2 where it may be seen that the rotating screen 28 includes an interior surface 32 and an exterior surface 34. A fixed blade 36 is positioned in contact with the interior surface 32 and the exterior surface 34 is perforated with a series of holes (40a, 40b) which form a pattern 38. Ink, supplied under pressure, is spread over the interior surface 32 as the rotating screen 28 revolves. Once spread, the ink passes through the holes, such as 40a and 40b which form the pattern 38. As the screen 28 rolls the pattern 38 into contact with the moving substrate 14, ink in the form of pattern 38 is transferred to the substrate 14. It should also be appreciated that the particular implementation for the printing stations 26a, 26b, 26c, 26d, 26e is representative and that other technologies are practical. For instance, the rotating screen 28 and fixed blade 36 shown in Figure 2 may be replaced with the intaglio roller 42 shown in Figure 3. The intaglio roller 42 features a rotating cylinder 44 with an exterior surface 46. An engraved design 48 is formed in the exterior surface 46. Ink applied to the design 48, is rolled onto the moving substrate 14 as the rotating cylinder 44 causes the design 48 to contact the substrate material 14. Referring again to Figure 1, it may be seen that a curing oven 50 is positioned between the guide rollers 22a and 22b to process the substrate material 14 after it has passed over the supporting surface 24 and under the printing stations 26a, 26b, 26c, 26d and 26e. The curing oven 50 applies ultra-violet or thermal energy to cure or harden the ink deposited by the printing stations 26a, 26b, 26c, 26d and 26e on the substrate material 14. It should be noted that the use of the curing oven 50 may not be required when self-curing inks are employed. Referring now to Figure 4, it may be seen that the apparatus 10 may be reconfigured to add additional laminating layers to the substrate material 14. In greater detail, it may be seen that the apparatus 10 of Figure 4 includes a secondary supply roller 52 wound with a supply of a laminating material 54. The laminating material 54 has an exterior side 56 and an interior side 58 and may be composed of numerous materials types such as clear or translucent plastic films and metalized mylar type foils. preferably, the interior side 58 of the laminating material 54 is coated with a pressure sensitive adhesive material. The laminating material 54 is unspooled from the secondary supply roller 52 and passed between the laminating rollers 60a and 60b. The laminating rollers 60a and 60b force the laminating material 54 firmly into contact with the substrate material 14 causing the pressure sensitive adhesive to bond the laminating material 54 to the substrate material 14. Alternatively, the laminating material 54 may be bonded to the substrate 14 by the use of a thermally sensitive or other type adhesive. OPERATION The apparatus 10 may be used to produce a wide variety of varying end products. For instance, to produce the display 62 shown in Figures 5 and 6, a translucent plastic material, or substrate 14, is wound around the supply roller 12 of the apparatus 10 of Figure 4. The substrate material 14 is attached to the take-up roller 16 and positioned to contact the printing stations 26a, 26b 26c, 26d and 26e. As electric motor 18 causes the substrate material 14 to move between the supply roller 12 and the take-up roller 16, a predetermined ink pattern is applied by each of the printing stations 26a, 26b, 26c and 26d. Specifically, printing station 26a applies a pattern 30a of red dots, printing station 26b applies a pattern 30b of blue dots, printing station 26c applies a pattern 30c of yellow dots and printing station 26d applies a pattern 30d of black dots. The synchronized rotation of the rotating screens 28 included in the printing stations 26a, 26b 26c and 26d ensures that the patterns 30a, 30b, 30c, and 30d are applied to the substrate material 14 with each successive pattern accurately registering over the preceding pattern. The successive application of the different colored inks by the printing stations 26a, 26b, 26c and 26d creates an ink layer 64 on the substrate 14. Additionally, it may be appreciated that by using different patterns for each of the patterns 30a, 30b, 30c, and 30d, a four-color image is formed by the ink layer 64. An example of such an image is shown in Figure 5 as the apple 66. After the ink layer 64 has been applied on the substrate 14 to create the apple 66, an extraordinarily thick layer of ink 68, is applied by the printing station 26e over the ink layer 64 on the substrate 14. As seen in Figure 5, the extraordinarily thick layer of ink 68 is applied to surround the periphery of the apple 66 on the substrate 14. It may be appreciated that application of an ink layer in this fashion creates an enhanced highlight and gives the apple 66 a quasi-three dimensional appearance. The relationship between the extraordinarily thick layer of ink 68 and the ink layer 64 is best seen by reference to Figure 6 where it may be seen that ink layer 64 has a thickness designated as 70 and extraordinarily thick layer of ink 68 has a thickness designated 72. As shown in Figure 6, thickness 72 is substantially greater than thickness 70. Preferably, thickness 72 is approximately twenty-five micrometers (25µm) and thickness 70 is approximately one micrometers (1µm). Practice has demonstrated that the extraordinarily thick layer of ink 68 is preferably formed using a viscous ink type curable by exposure to ultraviolet radiation. To cure the extraordinarily thick layer of ink 68, the substrate material 14 is passed through a curing oven 50 where the substrate material 14 is exposed to an ultraviolet radiation source. Alternatively, other ink types may be used in cases where thermal curing is more desirable. For the purposes of the present invention, the extraordinarily thick layer of ink 68 may be replaced or augmented by additional types of enhanced highlights. For instance, the printing station 26e may be used to apply an ink layer containing visual dissimilarities such as metalized flakes or crystallized pigments. In cases where the extraordinarily thick layer of ink 68 is used in conjunction with an enhanced highlight using visual dissimilarities, an additional printing station of the same type as 26a, 26b, 26c, 26d or 26e may be added. In the same manner, an additional printing station, such as printing stations 26a, 26b, 26c, 26d or 26e may be added to apply an additional ink layers, like ink layer 64 using translucent or opaque inks. To complete the display 62, a metalized mylar or foil 74 is wound on the secondary supply roller 52 and used as the laminating material 54. The interior side 58 of the laminating material 54 carries a pressure-sensitive adhesive. The laminating material 54 passes between the laminating rollers 60a and 60b where it is forced firmly into contact with the substrate material 14. As the laminating rollers 60a and 60b force the laminating material 54 and the substrate material 14 into contact, the pressure-sensitive adhesive bonds the laminating material 54 and the substrate material 14 together. Alternatively, the laminating material 54 may be bonded to the substrate 14 by the use of a thermally sensitive or other type adhesive. The process of the present invention completes when the substrate material 14 wound on the supply roller 12 is completely transferred to the take-up roller 16. At completion, a repeated series of images has been applied to the substrate material 14. These images may then be separated into individual displays, such as display 62, using any well known methodology. While the particular system and method for manufacturing displays as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of the construction or design herein shown other than as defined in the appended claims.

Claims: A method for manufacturing designs and signage which comprises the steps of: extending a continuous sheet (14) of material through a series of printing stations (26a,26b,26c,26d) between a supply roller (12) and a take-up roller (16); rotating said take-up roller to transfer said sheet from said supply roller to said take-up roller; forming an ink layer (64) by sequentially depositing a plurality of colored ink dots (30a,30b,30c,30d) onto said sheet during transfer of said sheet from said supply roller to said take-up roller, each said colored ink having a specific color and being deposited at a respective said station to create a design (66) on said sheet characterised by creating enhanced highlights with an extraordinarily thick ridge (68) of ink by depositing additional ink of a viscous type on selected portions of said design during transfer of said sheet from said supply roller to said take-up roller, the thickness (72) of the extraordinarily thick ridge of ink being substantially greater than the thickness (70) of said ink layer; and curing said inks on said sheet during transfer of said sheet from said supply roller to said take-up roller. A method as claimed in Claim 1 wherein the thickness (72) of the extraordinarily thick ridge of ink (68) is approximately twenty five micrometers and the thickness (70) of the ink layer (64) is approximately one micrometer. A method as recited in claim 1 or 2 wherein said extraordinarily thick ridge of ink (68) is deposited using a pressurized cylindrical screen. A method as recited in claim 1 or 2 wherein said extraordinarily thick ridge of ink (68) is deposited using a sequence of print rollers. A method as recited in claim 1 or 2 wherein said extraordinarily thick ridge of ink (68) comprises a viscous translucent ink. A method as recited in claim 1 wherein said step of creating enhanced highlights includes depositing an ink having visual dissimilarities suspended therein. A method as recited in claim 6 wherein said visual dissimilarities are metallized flakes. A method as recited in claim 6 wherein said visual dissimilarities are flecks of crystallized pigment. A method as recited in claim 1 wherein said step of sequentially depositing a plurality of inks is accomplished by separately depositing yellow, blue, red, black and white inks as required to generate appropriate colors for said design. A method as recited in claim 1 wherein said inks are sensitive to ultraviolet light and said curing step is accomplished by exposing said inks to ultraviolet light. A method as recited in claim 1 wherein said curing step is accomplished by exposing said inks to heat. A method as recited in claim 1 further comprising the step of laminating a layer (54) to said sheet to position said inks therebetween. A method as recited in claim 12 further comprising the steps of depositing an adhesive over said inks to hold said layer against said sheet. A method as recited in claim 13 wherein said adhesive is a pressure sensitive adhesive. A method as recited in claim 13 wherein said adhesive is a thermal sensitive adhesive. A method as recited in claim 12 wherein said layer (54) is a metallized mylar to create a reflective backing for said design on said sheet. A method as recited in claim 12 wherein said layer (54) is a foil to create a reflective backing for said design on said sheet.

Inventors: LOVISON DOUGLAS I, LOVISON, DOUGLAS I.
Applicants: CHROMIUM GRAPHICS INC, CHROMIUM GRAPHICS, INC.
Application year: 1996
Main classification: B41F15
IPC codes: B41F15, B41M1, B41M3, B41M7