Manually changeable displays

Abstract: Two thin sheets (10, 11) of material have slits to define coplanar flaps (12AA-12GG and 12A-12G) that are configured and arranged in conformity with segments of a segmental display such as a seven-segment digital display. The layers are superimposed such that corresponding segments are superimposed. The layers have contrasting colors. Applying a force against a typical overlying flap (12AA) in a segment causes the overlying (12AA) and underlying (12A) flaps to deflect in the same direction for the outer edges (22, 23) of the flaps to pass each other. When the force is removed the flaps restore to positions that are substantially coplanar with the layers in which they are formed. When the flap (12AA) in the overlying layer is coplanar with its layer that flap and, hence, the segment (A) is not visible because there is no contrast between the flap and the layer being viewed. When the flap (12A) of the underlying layer is caused to switch over the flap (12AA) in the overlying layer there is contrast between the flap and the overlying layer so the segment represented by the flap is visible.

Description: Background of the Invention The invention disclosed herein pertains to segmented displays arranged to depict seven-segment digits, letters of the alphabet and symbols and wherein the segments can be made selectively visible or invisible to effectuate having the same display adaptable to represent any digit from 0-9 and any letters of the alphabet, for example. The basic concept of a display device which may have its segments easily changed by hand in order to display the numerals 0-9 is known. Displays of this type are useful where changes must be made relatively frequently in numbers or letters such as in signs that display prices or other alphanumeric values. The concept used herein of slitting two sheets of flexible plastic to create flaps that are free on three edges and attached on one bending line to the sheets and then superimposing the sheets to place corresponding flaps in congruences so that pressing a flap which overlays another causes the flaps to pass each other and exchange positions, is known from United States Patent No. 3,296,726, dated 10 January 1967. This patent does not, however, show or suggest how to use the concept to make changeable alphanumeric segmented character displays as are disclosed herein. Summary of the Invention A digital display according to the present invention comprises a planar first layer and a viewable second layer overlaying the first layer. The layers are composed of a material that deflects or bends when a force is applied and is self-restoring to undeflected condition when the force is removed. The layers each have slits defining flaps configured and arranged in a pattern representing the segments of a seven-segment digit or other characters or symbols. The flaps constituting a segment are superimposed and subject to being deflected so that one passes the other in response to a manual force being applied. Passing of the flaps causes the underlying flap to become the overlying flap. One flap for each segment in the second or overlaying layer has the same color as the area surrounding said flap in the second layer. This makes the flap on top, and hence, the particular segment invisible by reason of there being no contrast between the flap or segment and the surrounding area. When the overlying flaps and underlying flaps are switched so that the underlying flap which contrasts with the background or second overlaying layer is on top, the segment represented by the flap becomes visible because of the contrast between it and the background color of the overlaying second layer. The invention is exemplified herein by showing and describing several versions of seven-segment digital or numerical displays. It should be understood, however, that the principles elucidated in connection with describing seven-segment digits are equally applicable to displays that represent letters of the alphabet or other characters or symbols. Letters of the alphabet, for example, simply require use of more segments to represent them and make them readable. Accordingly, in the ensuing specification, the term "seven-segment digital display" shall be construed as being replaceable and exchangeable with "multiple-segment alphabetic character" or other symbol and in the claims the term "segmented display" is used as the generic expression for digital displays, numeric displays and other displays of characters and symbols that are defined by segments arranged in a predetermined pattern, including dot matrix displays in which characters can be formed from, for example,a 5 x 7 dot matrix. An objective of the invention is to provide a segmented display such as a seven-segment digital display or alphabetic display wherein any of the segments may be switched to a visible or invisible state to convert from one digit or letter to another by simply applying a force to them manually and wherein the segments remain in a stable state until a force is applied again. Another objective of the invention is to provide a display that does not have parts which could be easily deformed, separated or lost from the sign in which the display is used. Still another objective is to provide a display wherein the changeable segments lie substantially in the same planes so that it appears to an observer that the display is printed or otherwise formed on a single layer. A further objective is to provide manually changeable displays that can be implemented with a variety of materials to provide for making the segments visible with back lighting and face lighting. How the foregoing and other more specific objectives of the invention are achieved will be evident in the ensuing description of illustrative embodiments of the invention which will now be set forth in reference to the accompanying drawings. Description of the Drawings FIGURE 1 is a perspective view of a sign that employs the new changeable segmented displays in the form of seven-segment digital displays; FIGURE 2 is a partial transverse section of a digital display taken on the line corresponding with 2-2 in FIGURE 1; FIGURE 3 is an exploded view of one embodiment of the digital display; FIGURES 4, 5 and 6 show a cross-section of one of the segments of the display and illustrate how, by applying a force manually, a segment in a display can be made visible or invisible; FIGURES 7, 8 and 9 are vertical sections through modified versions of the display and are used to represent different back lighted versions of the new display, one version of which uses polarizing layers to make segments of the display visible and invisible; FIGURE 10 illustrates another alternative form of the display for back lighting; FIGURES 11 and 12 are sections through the display of FIGURE 10 that show how one of the segments can be converted from a visible state to an invisible state and vice versa; and FIGURE 13 is an exploded perspective view of another alternative embodiment of the display. Description of a Preferred Embodiment Refer to FIGURE 1 for an overview of the new display. In FIGURE 1 the displays currently represent the digits 3278. The segments of the displays are designated in the conventional manner with letters A-G which have been applied only to the numeral 8 in FIGURE 1. The segments included in the group A-G in any of the numerals are visible because they contrast with the background color of what is called herein, a second or overlying viewable planar layer 10. This layer is a thin sheet of plastic or other flexible material which has the property of restoring to a planar condition after having been deflected by a manual force which is subsequently discontinued. As will be explained later, the visible segments A-G in the numeral 8, for example, are flaps that are developed in a first planar layer that has the bending or deflecting properties of the second layer 10 but underlies the upper or second layer 10 which is visible to the viewer. Any of the segment flaps are deflectable against their contrasting mate to bring about disappearance or appearance of the segment. For example, the segments F and E are not visible in the numeral 3 of FIGURE 1 because they are coplanar with layer 10 and are not contrasting with layer 10. As will be explained, by applying a manual force to any of the flaps constituting a digit segment, whether it is invisible or visible, results in the opposite effect. Attention is now invited to FIGURE 3 which depicts the components of one of the digital displays constructed in accordance with the invention. The planar first or underlying layer comprising a digit is designated generally by the numeral 11. Flaps constituting segments of a digit are stamped or die cut in the layer. For example, flaps such as the one marked 12A, are defined by slits such as the one marked 13. Typical slit 13 terminates desirably in holes 14 and 15 which facilitates bending or deflecting the flap. A dashed line 16 extending between holes 14 and 15 represent the imaginary hinge line on which the flaps deflect out of the plane of layer 11 when a force is applied to them. When the deflecting force is removed, of course, because of the inherent characteristics of the layer 11 material, the flaps self-restore to coplanar condition with first layer 11. Another layer, generally designated by the numeral 10 overlays or is superimposed on first layer 11 as is evident in FIGURES 2 and 3. By way of example and not limitation, the layers may be acrylic, polyvinyl chloride, polyethyleneterphthalate, polyethylene, polycarbonate, polyester, polystyrene, polypropylene, Mylar, plastic coated paper, acetate resins and the like. Returning to FIGURE 3, one may see that second layer 10 is also slitted to define flaps configured and arranged in a pattern representing the segments of a seven segment digit. In the second or overlying layer 10, the flaps are designated 12AA to 12GG. A flap 12AA, for example, in layer 10 is superimposed on a flap 12A in the underlying first layer 11. Typical flap 12AA in second layer 10 deflects or bends along an imaginary line such as the dashed line marked 21. Typical flap 12A in first layer 11, as previously indicated, bends along a dashed imaginary line marked 16 and has an outer edge 22. Superimposed flap 12AA in second layer 20 has an outer edge 23. Note that as the layers 11 and 20 are oriented in FIGURE 3, flap 12A in layer 11 extends from its hinge or bending line 16 upwardly to terminate in edge 22. On the other hand, the mating flap 12AA in second layer 10 extends downwardly from its hinge line 21 to terminate in an edge 23. It will be evident that all of the flaps 12AA-12GG in second layer 10 have their hinge lines superimposed on the outer edges of the flaps in first layer 11. As a consequence, when superimposed flaps are deflected concurrently, the flaps can pass each other so that the flap which was originally coplanar with the second or overlying layer 20 becomes underlying and hidden while the flap that was underlying shifts to the top and becomes substantially coplanar with the second layer. If the top flap is the one that contrasts with the top or overlying layer then the segment represented by the flap is visible. The superimposed flaps may be mounted on a holder or support such as the one generally designated by the numeral 30 in FIGURE 3. The support 30 may be formed of a plastic or other lightweight material. If the displays are only front lighted, the support 30 can be opaque. If the displays are back lighted, the support can be translucent, or transparent. There are two raised areas in the form of hollow pads 31 and 32 formed in the support body 30 in FIGURE 3. The central non-bending zones 60 and 61 surrounded by flaps 12A, 12B, 12G and 12F, for example, or their counterparts 12AA, 12BB, 12GG and 12FF, respectively, in the other layer of the flap containing layers can be adhered to each other and to the faces of pads 31 and 32 to prevent the layers 11 and 10 from shifting and to provide for the structural integrity of the centers of the FIGURE 3 configuration. In FIGURE 2, the outer or free edge of a typical flap 12FF in second layer 10 is marked 34 as it is in FIGURE 3. The outer edge of typical mating flap 12F in first layer 11 is marked 35 as it is in FIGURE 3. Attention is now invited to FIGURES 4-6 which will be used to illustrate how a segment of the new segmented display can be converted from a visible to an invisible state. In FIGURE 4, the first layer 11 contains the flap 12F of a typical segment. The outer or free edge of flap 12F is marked 35. The second or overlying layer 10 has flap 12FF formed in it. The outer or free edge of flap 12FF is marked 34. Assume, for the sake of illustration, that layer 10 is opaque and black and the underlying layer 11 is white. Under the conditions existing in FIGURE 4, flap 12FF would be substantially invisible or not discernible as a segment because it is black and black does not contrast with the surrounding black area of second layer 10. Flap 12F, on the other hand, is white. Now, in order to make the segment visible, it is only necessary to press directly against the exposed flap with one's finger or an instrument such as a pencil 54. In FIGURE 5, that operation has been carried out to the extent of having the outer end 34 of black flap 12FF pass the outer end 35 of what was formerly the concealed white flap 12F. In FIGURE 6, the force applied to the flaps has been discontinued and white flap 12F has become exposed for viewing as one of the segments of the digital display. Thus, the segment defined by white flap 12F has become visible because it has a color that contrasts with the color of layer 10. The superimposed layers 11 and 10 are thinner in actual embodiments than they appear to be in the drawings. In an actual embodiment, the layers are on the order of 0.0127 to 0.0381 cm (0.005 to 0.015 inch) thick, depending on the scale of the digit display. Layers of polyvinyl chloride, polypropylene, polystyrene, polyethyleneterephthalate, polycarbonate, polyester and Mylar of about this thickness can be used by way of example and not limitation. In FIGURE 6 it appears that the flaps 12F and 12FF are noticeably angulated and are not substantially coplanar with their surroundings. However, in an actual embodiment, because of the thinness of the layers, the visible flaps appear to be fully coplanar with the contrasting surrounding area on the foremost or viewable layer 10. FIGURES 7-9 are used to demonstrate two different back lighted versions of the displays. These versions are both designed to make the selected exposed segments of the digital display visible and illuminated in an otherwise dark ambient. In respect to one version, items that are structurally similar to those in the previously discussed embodiments are given the same reference numerals even though they may be composed of a different material in the later discussed version. In the first version of the invention to be discussed (of the two versions represented by same FIGURES 7-9), the so called first layer 11 is comprised of a material known by the trade name LISA (light intensifying sheet acrylic). This material or its equivalent has the property of appearing to fluoresce or to act as a light pipe when it is edge lighted or exposed to a beam of light directed at any angle including perpendicularity to its surface. LISA is available in a variety of colors. The flap 12F which is die-cut in the layer 11 mentioned above is composed of the material LISA. The free edge of LISA flap 12F is marked 35 in FIGURE 7. Layer 10 is opaque and may be black or any color that contrasts with the color of the LISA. The free edge of flap 12FF in layer 10 is marked 34. Intimately bonded to the rear or inside of typical LISA flap 12F is a layer 40 which is primarily a light reflector. This thin layer 40 may simply be printed white or it can be a thin film of white plastic material or paper such as a decal. Flaps 12F and 12FF are positioned over channel 33 of support 30. Even though light is projected from tubular light source 53 onto the backside of layer 11 in FIGURE 7, no lighted segment is presently visible from the front because the overlaying layer 10 is, for illustration purposes, black and opaque. Thus, when opaque layer 20 is viewed in the direction of the arrow 42, the flap 12FF formed in layer 10 will not be discernible as a segment because there will be no contrast between the flap and the surrounding area of layer 10. The mounting or support member 30 in FIGURE 7 may be transparent or translucent. In FIGURE 8, flap 12F, composed of LISA material, has been manually deflected along with the flap 12FF. The outer edge 35 of flap 12F has passed under flap 12FF in FIGURE 8. Thus, when the force that is causing deflection of the flaps 12F and 12FF is removed as is the case in FIGURE 9, flap 12F, by reason of its inherent springiness, restores to substantially coplanar position and flap 12FF comes down upon it. At this time reflective layer 40 is between opaque flap 12FF and fluorescent LISA flap 12F. With the opaque flap 12FF behind the reflector layer 40 and the fluorescent LISA layer 12F, the fluorescent layer becomes visible to one looking at it in the direction of the arrow 42 because flap 12F is illuminated by light directed from light source 53 at layer 11. The part of flap 12F that is under reflector 40 lights up because LISA fluoresces and acts somewhat like a light pipe, even though light rays impinge only to the sides of the opaque reflector 40. The next version of the display to be discussed using FIGURES 7-9 and the same reference numerals for the same elements even though different materials are used compared to the version just discussed. This version is also suitable for back lighting in that the illuminated segments can be seen in a dark ambient. In FIGURE 7, layers 11 and 10 are thin films that are polarized orthogonally relative to each other. For example, layer 11 and flap 12F therein may be considered to have zero degrees of polarization and layer 10 and flap 12FF therein may be polarized at 90° relative to layer 11. Layer 11 has intimately bonded to it a thin layer 40 of a depolarizer or birefringent material. A birefringent material 40, as is known, is a material that separates a light ray into two unequally refracted, plane polarized rays having orthogonal polarizations. This occurs in crystalline materials in which the velocity of light rays is not the same in all directions. It is also called double refraction material. The birefringent material used may be an acetate. It has been found that a white tissue paper is also reasonably effective as a depolarizer which may be used in place of the birefringent film 40. When the layers 10, 11 and depolarizer or birefringent layer 40 are arranged as they appear in FIGURES 7, and 8, no light would be visible to a viewer looking in the direction of the arrow 42 if a light beam were projected toward the back of birefringent layer 40 in the direction of the arrow marked 47 because of the orthogonal polarization of flaps 12F and 12FF. When, as in FIGURE 9, the flap 12F is deflected so as to be on the opposite side of flap 12FF as compared with FIGURES 7 or 8, the depolarizing or birefringent layer 40 becomes interposed between flaps 12FF and 12F. Since the birefringent layer 40 rotates or depolarizes light passing through flap 12FF, the light will also pass through flap 12F. Thus, a light beam from source 53 would be seen to illuminate flap 12F to a viewer looking in the direction of the arrow 42 toward flap 12F which, of course, constitutes a visible flap in a segment of the seven-segment display. Another version of the new segmented display is depicted in FIGURES 10-12. This embodiment is also capable of being visualized in a dark ambient by reason of it being subjected to back lighting. Referring to FIGURE 11, the second or overlying layer plastic sheet 10 may be considered to be black or opaque. It has the flaps 12AA to 12GG stamped or die-cut in it. The underlying layer 11 has the seven-segments 12A-12G but they are more complex in construction than those heretofore discussed as will be evident in reference to FIGURES 11 and 12. In FIGURE 11, for example, a typical flap 12FF in the overlying layer 10 is opaque so that if it were viewed in the direction of the arrow 42 there would be no visualization of a segment of the display because the flap 12FF is black and opaque as is the adjoining area of layer 10. The outer edge of flap 12FF in FIGURE 11 is marked 35 as it is in previously discussed embodiments. The underlying typical corresponding flap, such as flap 12F derived from layer 11, has a triangular configuration as evident in FIGURE 11. The flap may be made up from a single piece of translucent white plastic material, for example. There is a gap 48 between support layer 30 and layer 20 due to the die-cut in layer 11 being bent into a triangle having three sides 49, 50 and 51. Side 51 in FIGURE 11 is shown with opaque flap 12FF overlying it. Under the conditions prevailing in FIGURE 11, an observer looking at flap 12FF does not observe a segment because there is no contrast between flap 12FF and the surrounding area of opaque layer 10. In other words, light beams emitted by light source 53 would not penetrate through the opaque flap 12FF. In FIGURE 12, however, the opaque flap 12FF has been manually deflected so as to pass the outboard tip 52 of triangular flap 12F. As shown, when manual pressure is released, flap 12FF remains in an angled open position, resting on the side 50 of flap 12F. Since flap 12F is translucent and appears white, the segment will be visible by reason of a light from source beam 53 being directed through it as indicated. As in the preceding figures, the thickness of the layers is exaggerated to facilitate drawing and viewing them. Thus, it appears that the bottom layer 51 of flap 12F is deflected rather than essentially coplanar with the adjacent layer 10 as compared with the perception one gets by looking at an actual embodiment of the display wherein it looks like portion 51 is coplanar with layer 10. Refer now to FIGURE 13. In this embodiment, the overlying layer 70 has die-cut flaps AA to FF and an opening 71. Layer 70 is opaque, although it may be colored as well as black. The underlying layer is made in two parts 72 and 73. The parts 72 and 73 have central areas 74 and 75, respectively, which are opaque and of the same color as overlying layer 70. Underlying layer part 72 has slitted deflectable flaps marked A, B, G and F on it. These flaps may be white or some light color that contrasts with the color of central area 74 and overlying layer 70. Underlying layer part 73 has deflectable flaps C, D, E and GG. Flap GG has the same color as central area 75 and overlying layer 70. The fold lines of the flaps are imaginary and indicated with dashed lines. The support 30 for a display is similar to previously described supports, so it and its parts are given the same reference numbers. Assembly of the FIGURE 13 display involves adhering the central region 74 of part 72 to riser pad 31, adhering the central region 75 of part 73 to riser pad 32 of the support 30, and adhering the rim of overlying layer 70 to the rim of the support 30. The result is an assembly wherein at the outset flap AA overlies flap A, flap BB overlies B, flap CC overlies C, and so forth. The central areas 74 and 75 of parts 72 and 73 are presented in the opening 71 of overlying layer or sheet 71. The central areas 74 and 75 have a color that matches the background color of opaque overlying layer 70. Flap GG is opaque and has the same color as central region 75. The flaps are defined by slits such those marked 76 and 77. The flap segments can be printed on or unprinted as required for contrast. Printing may be done in a press or by silk screening or color may be imparted by applying decals. The FIGURE 13 design lends itself to the use of LISA and polarizing materals as in the FIGURES 7-9 embodiment or to loop-shaped flaps as in the FIGURES 10-12 embodiment. The appearance is improved because the segments touch and are separated only by the slits. This makes small digits possible. The principles of the various embodiments or versions of the segments described herein can be applied to dot matrix displays, not shown. Especially in very large displays it is advantageous to break up what would otherwise be very long and wide segments into smaller segments characterized as dots. A plurality of dots used in place of one segment provides greater flexibility as to patterns that can develop which is especially desirable when the displays are for complicated configurations. The changeable segments described herein may, for example, be used to create the well known 5 x 7 dot matrix displays.

Claims: A manually changeable display comprising: a planar underlying layer (11) beneath a planar overlying layer (10); each layer comprising a number of flaps (12) of which each flap (12A-12G) in one layer is shaped and positioned to overlie or underlie a corresponding flap (12AA-12GG) in the other layer; each flap being joined to the remainder of the layer in which it is formed along a bending line (16) about which it is resiliently deformable in response to an applied force; each flap formed in the first layer extending in the plane of the first layer away from its bending line in a direction opposite to that of the corresponding flap formed in the second layer, so that depression of any superposed flap by application of a deflecting force causes that flap to pass beneath the corresponding flap in the other layer so that on removal of the deflecting force the flaps restore to their original planar condition except that the initially covered flap becomes the superposed flap; CHARACTERISED IN THAT the pairs of corresponding flaps (12A-12G, 12AA-12GG) in the first and second layers (10,11) form the segments (A-G) of a segmented display; and one flap in each segment is made of a material, or is coloured, to contrast with the surrounding area, and the other flap of each segment is made of a material or is coloured to mask or conceal that contrast. A display according to claim 1, wherein in a particular flap configuration the uppermost surface of the overlying flap has a colour which contrasts with that of the surrounding area and when the flap configuration is reversed so that the said flap with a contrasting colour is the underlying flap, the overlying flap has a colour which matches that of the surrounding area. A display according to claim 1 or claim 2, wherein the first and second layers (11,10) are formed from polystyrene, polypropylene, polyethylene, polyethylene-terephthalate, acrylic polymer, polyvinyl chloride, a polycarbonate, a polyester, an acetate resin or a plastic-coated paper. A display according to claim 1 or claim 2, wherein a layer of light reflective material is bonded to the undersurface of one or more flaps (12A-12G) in the underlying layer (10). A display according to claim 1, wherein the underlying layer (11) is formed from a sheet of light intensifying sheet acrylic (LISA) and the overlying layer (10) has a colour that contrasts with the colour of the LISA sheet (11) and is opaque or non-light transmissive. A display according to claim 1, wherein the flaps (12A-12G) of the underlying layer (11) and the flaps (12AA-12GG) of the overlying layer (10) are formed from transparent or translucent materials which are optical polarizing filters, the planes of polarization of the flaps in the respective layers being mutually perpendicular, and a layer of birefringent or depolarizing material is applied to one surface of one flap only of each pair of corresponding flaps. A display according to claim 6, wherein the birefringent material is an acetate film or tissue paper. A display according to claim 1, wherein the overlying layer (10) is opaque, and each flap (12A-12G) of the underlying layer (11) is formed of a transparent or translucent material and carries on its underside a transparent or translucent structure (49,50) to hold the associated flap (12AA-12FF) of the overlying layer (10) clear of the said underside when the flap (12A-12F) of the underlying layer (11) becomes the overlying flap, to allow light transmission therethrough. A display according to claim 8, wherein the transparent or translucent structure (49,50) comprises a folded back loop of the material of the underlying layer (11). A display according to any preceding claim, including a support member (30) having areas (31,32) surrounded by a channel (33), wherein the underlying layer (11) has zones (60,61) surrounded by the flaps (12A-12G) and mounted on the said area (31,32) with the flaps (12A-12G) overlying the channel (33) to allow for deflection of the flaps into the channel. A display according to claim 10, wherein the underlying layer (11) is formed in two parts (74,75) each of which is mounted on a respective one of the areas (31,32).

Inventors: BAILEY WILLIAM MARSHALL, BAILEY, WILLIAM MARSHALL
Applicants: EVERBRITE INC
Application year: 1993
Main classification: G09F9
IPC codes: G09F9