US 3146492 A
Description (OCR text may contain errors)
Sept. 1, 1964 J. H. LEMELSON 3,146,492
APPARATUS FOR MAKING A LENTICULAR DISPLAY SHEET Filed Dec. 18, 1957 INVENTOR.
JEROME H.LEMELSON United States Patent 3,146,492 APPARATUS FOR MAKING A LENTICULAR DISPLAY SHEET Jerome H. Lemelson, 85 Rector St., Metuchen, NJ. Filed Dec. 18, 1957, Ser. No. 703,523 3 Claims. (Cl. 18-10) This invention relates to apparatus for manufacturing a sheet display material and is a continuation-in-part of application Serial No. 559,232 filed on Jan. 16, 1956, and now U.S. Patent 3,026,648.
It is known in the art to fabricate a display device having a sheet of plastic with ribbed lens formations provided in the outer face thereof and multiple images defined by interspersed image bands disposed immediately adjacent the other face of the plastic which is flat. Such a display device is generally made of two or more sheets, a second sheet being used to support and position the illustration. A typical display device of this type contains illustrations which appear to change in content to an observer as the angle between line of sight and the face of the display changes.
Heretofore, displays of the above mentioned type have been fabricated by manually aligning two or more sheet materials including the capping or lens sheet and the sheet containing the multiple illustrations.
It is a primary object of this invention to provide a new and improved multiple image sheet display and apparatus for producing said display at low cost.
Another object is to provide an apparatus for automatically producing a lenticular sheet display material on a continuous basis.
Another object is to provide an apparatus for producing a sheet display material by extruding said sheet material and thereafter performing operations thereon for providing multiple illustrations against a flat face of said sheet and multiple lens formations in the other face of said sheet which are aligned with respective portions of the illustrations and cooperate therewith in creating changeable optical effects.
The above as Well as further objects, features and advantages of the present invention will be best appreciated by reference to the following detailed description of a preferred embodiment, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a diagrammatic representation of a preferred apparatus for continuously producing a lenticular sheet display material;
FIG. 2 shows a modification to the apparatus of FIG. 1;
FIG. 3 is a side view of part of the apparatus of FIG. 1 with parts removed for clarity; and
FIG. 4 is an end view of part of a modified embossing roll applicable to the apparatus of FIG. 1.
In FIG. 1 there is shown an apparatus for continuously producing a lenticular sheet material by performing a plurality of operations on a sheet of plastic as it is fed through said apparatus. The plastic sheet 20 is fed from a supply roll 21 thereof which is rotationally supported by conventional means. The sheet 20 feeds from 21 through an assembly 22 of opposed guide and drive rolls 22a and 2212 prior to being admitted to the bite of a rotary printing press 23 having a printing roll 24 and a depressor roll 25 cooperating therewith to provide a printed pattern on the surface 20 of the sheet 20. Thereafter the sheet 20 is driven immediately adjacent a drying apparatus 26 which may comprise one or more heaters and/ or blowers operative to continuously flow warm air against the surface 20 to dry the ink applied thereto.
The printing provided on the face 20' of sheet 20 by the printing press 23 comprises an illustration consisting of a pattern having a plurality of parallel and separated image bands including a first array of spaced bands which are 3,146,492 Patented Sept. 1, 1964 repetitive in arrangement and substantially equispaced and define a first image field. The bands of the first image field are interposed between a second array of printed bands which are also substantially equispaced from each other by said first bands and have dissimilar image characteristics than the first bands and define a second image field. By the means described hereafter, the other face 20" of the sheet 20 is shaped with a plurality of parallel lenticular rib-like formations which are aligned and substantially parallel to the printed image bands so that the sheet 20 becomes a display material which exhibits changes in optical composition as the line of sight of the observer moves relative to the display material. Reference is made to my copending application Serial No. 360,954, filed June 11, 1953, and to U.S. Patent 2,951,419 which issued on September 6, 1960, for a Reflective Display Device for a further description of a display material having at least certain characteristics which are similar to those of the material producible by means of the apparatus of FIG. 1.
After passing the drying apparatus 26, the sheet 20 is next passed through rolls 27 and 28. The lower roll 28 is operative to form said mentioned lenticular formation in the face 20" of the sheet 20 on a continuous basis by embossing said lenticular formations therein.
If sheet 20 is a thermoplastic material such as a synthetic polymer, glass or the like it may be rendered semimolten by radiant heaters provided in the apparatus 26 so as to be formable by the embossing roll 28 with a plurality of parallel lenticular formations as it is driven therethrough. The lenticular formations are shaped as illustrated in FIGS. 3 and 4 as a plurality of parallel, side-byside rib-like lens formations, preferably of semi-cylindrical shape which serve to generally confine the portion of the multiple image display printed on the rear face 20' of the transparent sheet that an observer may view through the sheet, to a particular group or arrangement of image strips.
Also illustrated in FIG. 1 are a plurality of sheets 34 and 37 which may be laminated to the flat face 20 of the sheet 20 on a continuous basis to provide a particular type of display. The sheet 34 may comprise a reflex-reflecting material which may be continuously and automatically laminated to 20' for rendering the display sheet reflexretlecting so that it may be used for highway signs and the like. Said sheet 34 is shown being fed from a supply roll 35 thereof and is laminated between a backing sheet 37 provided from its supply roll 36, the three sheets 20, 34 and 37 being fed to the bite of the embossing and laminating rolls 27, 28 as shown. Notations 38 and 39 refer to spray applicators for applying coatings of adhesive material to opposite faces of the sheet 34 to effect the bonding of the three sheets together.
After passing through the rolls 27, 28 the sheet material is fed to the bite of a pair of aligned feed and drive rolls 32, 33 beyond which the sheet material may be cut to predetermined lengths or formed in a press 40 illustrated as a flying bed press which is operative to deform the sheet as it moves. Notation 41 refers to a shear operative to engage and cut the sheet into predetermined lengths 20T after said sheet has been formed as described which lengths are carried by a belt conveyor 42 away from the press 40.
The apparatus of FIG. 1 may be modified as illustrated in FIG. 2 by supplying the light transmitting sheet material 20 directly from an extruder 43 from which the extruded sheet is passed to said feed and guide rolls 22a, 22d prior to being fed to the printing press 23. In a preferred form of the invention, the sheet 20 is substantially solidified by the time it enters the printing press 23 although the elevated temperature thereof is preferably maintained so that the sheet may be easily embossed or provided in a condition whereby it may be deformed as described by the embossing roll 28.
In FIG. 3 is shown part of the embossing apparatus for providing said parallel lenticular formations L extending across the sheet at an angle to the longitudinal axis of the sheet. The embossing roll or drum 28 is shown having rib-like formations 29 provided therein which define parallel indentations 29' extending parallel to the axis of rotation of 28 which is defined by the shaft 30 supporting said drum. The indentations 29 are operative to emboss or mold rib lenticular formations 20L in the front face 20 of light transmitting material 20 with said formations 20L extending aligned with the printing provided against the other face 20' of 20. The shaft 31 of smoothly faced cylindrical roll 27 extends parallel to and in alignment with shaft 30 of embossing drum 28. The said display illustration disposed against the flat side of layer or sheet 20 may also be provided as matter printed on the surface of sheet 34 which abuts said lens sheet 20 in forming the completed display material.
FIG. 4 illustrates the lenticular formation embossing means modified whereby the embossing roll 28 has a plurality of rib formations 29a defining semi-cylindrical cavities 29a therebetween which extend peripherally around the working face of the roll rather than parallel to the axis of rotation as do the embossing formations in the roll 28 of FIG. 3. The embossing roll 28' is thus operative to provide a plurality of side-by-side rib-like lenticular formations which extend parallel to the longitudinal axis of the sheet rather than perpendicular or oblique thereto. The illustrative material provided against the flat face of sheet 20 in the modified apparatus of FIG. 4 thus extends as a plurality of bands parallel to said rib formations and accordingly substantially parallel to the longitudinal axis of the feeding sheet.
A latitude of modification, substitution and change is intended in the foregoing disclosure and it will be appreciated that features and concepts derived from the several figures may be employed in varying combinations to provide different sheet materials and display articles. In some instances some features of the invention will be used without a corresponding use of other features. It is therefore intended that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the disclosure herein.
1. Apparatus for producing a lenticular display sheet material containing a visible illustration which changes to an observer as his line of sight changes relative to said material comprising in combination, means for providing a continuous web of a transparent thermoplastic material as a sheet, means for continuously feeding said sheet and providing an illustration against a first face of said sheet which illustration comprises a pattern consisting of a plurality of parallel and separated image bands including a first array of spaced bands which are repetitive in arrangement and substantially equispaced to define a first image field, and which bands are interposed between a second array of printed bands which are substantially equispaced from each other and have dissimilar image characteristics than said first bands for defining a second image field, said apparatus including means for guiding and moving said sheet material in a predetermined path, means for supporting said first face of said sheet material, means for rendering said material semi-molten, an embossing means including a first cylindrically shaped roll which is void of surface formations and is shaped for continuously supporting said first face of said sheet material, a second embossing roll having parallel rib-like formations defining parallel cavities in its working surface, said embossing roll adapted for shaping the other face of said sheet material while semi-molten, in cooperation with said first roll, means for guiding said sheet material through said embossing means to effect the molding of rib-like lenticular formations in said other face of said sheet material which rib formations extend substantially parallel to and aligned with said image bands and are shaped as a plurality of elongated lenticules which are operative to provide the aforedescribed optical effect.
2. Apparatus in accordance with claim 1 in which said means for providing said web thermoplastic material comprises an extrusion machine including a die for expressing said material as a sheet.
3. Apparatus in accordance with claim 1 in which said means for providing said continuous web comprises means for supporting a roll of said thermoplastic sheet material, and means for printing said illustration on said first face of said sheet material as it is fed from said roll.
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