DISPLAY OBJECT

TECHNICAL FIELD

The present invention relates to a product comprising an image display object, which may be decorative and/or informative in nature, intended to be placed indoors or outdoors, in private or public buildings or grounds.

BACKGROUND

Light boxes are well known in the art of displaying messages, symbols or artistic pictorial art, such as photos, paintings etc. Usually such displays are painted, engraved or screen printed on transparent glass or on a plastic material and may be illuminated by a light source from behind. Typically, this kind of display is used by shops, malls, restaurants, hotels and similar businesses to attract attention from the public. Other uses are text messages or symbols e.g. to inform and direct the public in public buildings and grounds. Some light boxes use opaque sheets, which have holes or apertures cut or punched to outline or portray a message, symbols or an image by back lighting. An observer standing in front of the sheet sees the message, symbol or image by the light that is transmitted through the holes or apertures. Either the light comes from a light source placed behind the opaque sheet, or incident light is reflected from a bright background behind the opaque sheet. Examples of prior art can be studied in U.S. Patent Application No. 2007/0289180 A1 and U.S. Patent No. 3,631 ,474.

Opaque sheets having cut-outs that convey a message or show a picture to an observer suffer from several drawbacks. For messages or pictures having details, which require fine resolution, punching holes or machining apertures have the disadvantage of being crude and only capable of mediocre resolution. This is due to mechanical limitations inherent in the punching or machining processes and also depends on the material being used in the opaque sheet. Furthermore, the level of contrast in the image or message is sometimes limited because of the limited ratio of removed material to remaining material in the punched opaque sheet. See, for instance, Japanese Patent Application No. 2002- 113996 A. The sheet thickness cannot be too thin if punching or machining techniques are to be used. SUMMARY

The present invention discloses a new image display object directed to improving the usability and quality of the message or picture to be displayed over prior art. An embodiment relates to an image display object comprising an opaque, self-sustaining sheet having a dedicated area that defines a web comprising multiple polygons. Each of the polygons comprises multiple pixels. The sheet material, typically metal material, in each pixel is selectively removable within the boundaries of the polygons. The dedicated area thereby presents an image formed by a multitude of remaining pixels for which no sheet material has been removed and by a multitude of removed pixels for which the metal material has been removed.

The polygons of the web are framed with respective frame areas where no pixels are defined and no sheet material can be removed. The polygon web provides mechanical strength and thereby contributes to the integrity of the image display object and prevents collapse of the sheet material.

An embodiment also relates to a method of producing an image display object. The method involves laminating the sheet with a photoresist material and providing a master tool defining an image to be created on said image display object. The laminated sheet with the master tool is exposed to light and developed. An etching process is then performed in order to selectively remove sheet material to form the multitude of removed pixels. The etched sheet is then cleansed of photoresist material and etching solution to form the dedicated area with the web of polygons and the multitude of removed pixels and remaining pixels together forming the image. Each polygon of the multitude of polygons comprises at least one pixel, preferably multiple pixels.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which: FIG. 1 illustrates an image display object conveying a Japanese written symbol;

FIG. 2 illustrates a magnified selected part of the image display object in FIG. 1 ;

FIG. 3 illustrates an image display object conveying a photograph; FIG. 4 illustrates a magnified selected part of the image display object in FIG. 3;

FIG. 5 illustrates an image display object conveying a picture and a text message; FIG. 6 illustrates a magnified selected part of the image display object in FIG. 5; and

FIG. 7 illustrates a preferred method of producing an image display object of the present invention. DETAILED DESCRIPTION

Throughout the drawings, the same reference numbers are used for similar or corresponding elements.

The image display object, illustrative object or sign of the present invention discloses a graphical image of any kind of 2-dimensional motive on a self-sustaining opaque sheet of a selected, preferably metal, material available in sheet form. Typically, the motive is selected as one that will be recognized and correctly interpreted by any person having eyesight.

The 2-dimensional motive, translated into a graphical, digitized image by use of a digital method such as CAD/CAM, comprises a multitude of non-overlapping tiny areas, so called pixels. The pixels are defined on the opaque sheet in a pattern like the squares of a chessboard. The pixels constitute the smallest elements of the graphical image and all of them are preferably of the same shape. Geometrically, the pixel is a two dimensional shape having from 3 up to 8 corners, but preferred shapes are a rectangle, a square or a rhomb. All together the pixels cover an area of the opaque sheet, where the graphical image of the motive is intended to be located. In a manufacturing process, material of the opaque sheet corresponding to each pixel is either left intact or entirely removed. Where such tiny areas of the opaque sheet are removed, light may be transmitted from a light source behind the opaque sheet to a person observing the sheet from the other side, i.e. front side thereof, whereby the graphical image, positive or negative, of the motive is conveyed to the person by means of the combined effect of material removed and material remaining of the opaque sheet. Alternatively, the light source may be replaced by a light reflecting sheet arranged behind the opaque sheet, whereby incident light may be reflected by the visible parts of the light reflecting sheet, thereby conveying the image to an observer on the front side.

In another aspect of the present invention, it is clear that pixels may be adjacent without having any material of the opaque sheet separating them physically apart from each other. However, it is also clear that material of the opaque sheet, corresponding to a single pixel or a cluster of pixels cannot be left intact if all adjacent pixel material has been removed. The sheet material corresponding to the single pixel or cluster of pixels would not stay in place, but fall off because of lack of physical support. Thus, the present invention introduces a web or pattern comprising a multitude of polygons on the opaque sheet. Preferably, the polygons are of equal size and geometry such that each polygon embraces the same whole number of pixels, but differently sized polygons embracing a higher or lower number of pixels may be used in different areas of the opaque sheet. The web connecting all polygons in a common net is given a certain mesh width, i.e. each polygon is provided with a frame area around its circumference where no pixels may be removed. The mesh width is selected to be as thin as possible, considering the opaque sheet material, its thickness and the size of the polygons. Typically, the frame width is selected to be within a range from 0.05 mm to 0.5 mm, end points included. The objective of the web of polygons is firstly to maintain physical stability of the opaque sheet after the manufacturing process where opaque sheet material of pixel size has been removed in different places, secondly to support the highest resolution possible of the graphical image to be displayed by the image display object of the invention.

Typically, polygons have diagonals in a range from 0.1 to 5.0 mm inclusive of range end points. Preferably, polygons are geometrically in the shape of a rectangle, particularly a square, or in the shape of a rhomb, but other geometric shapes may be used. Furthermore, if the image display object of the present invention is intended to be displayed in a generally vertical plane, it is to be preferred that the web of polygons is arranged such that the directions of the frame main axis are generally not horizontal. In such a case, the strain on the mechanical structure of the image display object is made less if the frame axis are generally in an angle of 45 degrees when projected onto the vertical plane.

In yet another aspect of the invention, a polygon comprises multiple, i.e. at least two, pixels. Typically, each polygon comprises a whole number of pixels in a range from 4 to 4096 pixels inclusive of range end points.

In a further aspect of the present invention a pixel may be infinitesimal in size, but from a manufacturing point of view it is not advisable to have a pixel main dimension smaller than 0.01 mm. Depending on the size of the opaque sheet and the intended application for the image display object, pixel sizes in excess of 1 mm may be used. However, typical applications use pixel sizes in a range from 0.02 to 0.2 mm inclusive of range end points .

In a first embodiment of the present invention the graphical image may present only visible outlines of the objects of the motive to be displayed, in other words a drawing, i.e. the level of contrast between light, where material has been removed, and no light, where material remains, seen from a distance, being generally near 100 %.

FIG. 1 illustrates an image display object 1 of a Japanese written symbol, which in the Japanese 5 tradition was made up of brush strokes of a contrasting ink on white paper. The symbol may be displayed very effectively as an image display object 1 by the present invention. The dedicated area of sheet 10 is defined by a frame area 11 of sheet in which there are no web of polygons 12 and no pixels. Polygons are here designated 12. The web of polygons 12 is obvious and clear to see in FIG. 1 , because all areas of pixel material are removed outside the brush strokes of the symbol. The symbol 10 as such is also clear to see, because all areas of pixel material in the brush strokes of the symbol are left intact. However, if it were not for the web material in the shape of polygons 12, which provides the necessary mechanical strength to support the symbol, the symbol would fall out of the image display object 1 and would not be possible to display. FIG. 2 illustrates a magnified selected part of the image display object in FIG. 1 corresponding to the white box in the figure. The web of equally sized polygons 15 12 is clear to see in FIG. 1 and FIG. 2, particularly where all tiny areas of pixel material 18 are removed, i.e. the white areas. The black mesh, i.e. the frame 14 around each polygon 12, is what remains of the opaque sheet besides the tiny areas of pixel material 16 within the boundaries of the symbol.

20 In a second embodiment of the present invention the graphical image may present gray scales of the objects of the motive to be displayed, in other words a proper picture emerges when seen from a distance. The image display object 2 of FIG. 3 illustrates a photographic picture in the dedicated area of sheet 20, which is rich in contrast and grey scales. A section corresponding to the white box of the picture is selected and magnified and illustrated in FIG. 4. The selected section is taken from a part of

25 the image display object 2 where the level of contrast is very high. In the magnified selection of FIG. 4 the bright sky is seen to the left and a part of the dark wall of a tower is seen to the right. The magnified selection shows conclusively how pixels 28 in a polygon 22 have been removed to 100 percent in the part showing the sky and to a much lower level, perhaps 5 to 10 percent, in the part showing the tower wall. An example of a removed pixel material of the opaque sheet is referenced 28 and an example of a

30 remaining pixel material is referenced 26. Each polygon 22 has a frame 24 of non-removable sheet material around its circumference.

A third embodiment of the present invention is illustrated in FIG. 5, a sign or image display object 3, where a photographic picture is combined with a printed message as an example of a typical application for the present invention. A section marked with a white box of the sign 3 is selected and magnified and illustrated in FIG. 6. A polygon 32 has a frame 34, which is only partially obvious to the eye because several tiny areas, pixels, remain within the polygon. An area 38, where pixel material has been removed, is shown and an area 36 where pixel material remains is also shown. FIG. 6 illustrates how pixel material is removed within each polygon shown, so that the image display object 3 as observed from a distance presents a true, high quality impression of the picture and the printed message to an observer.

Materials that are suitable for the opaque sheet are preferably metals, such as aluminum, copper, brass etc, but more preferably steel and most preferably stainless steel, but thermoplastic materials laminated with a metal and glass laminated with a metal may also be used. Typically, suitable metal sheets are in a range from 0.03 mm to 5 mm in thickness. Preferred ranges include 0.05 mm to 0.5 mm and more preferably 0.1 mm to 0.5 mm. These thicknesses are thick enough to get a self-sustaining sheet but are still thin enough to enable removal of sheet material to form removed pixels by etching, water cutting and laser cutting at realistic processing times.

Non-exclusive methods of manufacture of the image display object include laser cutting, water cutting and etching. Particularly laser cutting and etching methods are extensively used in the electronics industry in the manufacture of stencils used in production of printed circuit boards. A preferred method of manufacture of the present invention is an etching method.

EXAMPLE

A preferred method of producing an image display object according to the present invention is shown in FIG. 7.

A photograph of the famous town hall in Stockholm, Sweden, was selected as the image to be projected as an image display object (see FIG. 3) in step S1. The photograph was scanned and digitized and further digitally treated in a CAD/CAM computer in step S2. A film of polymer was then plotted with the digital information and made into a master tool for an etching process in step S3.

A 0.1 mm thick sheet of stainless steel having a suitable area size was selected as an opaque, self- sustaining sheet in step S4. After thorough cleaning, the sheet was laminated on both sides with photoresist material in step S5. The laminated sheet was then put in a light exposing equipment, e.g. UV-based light, together with the master tool and exposed to light on both sides in steps S6 and S7. The exposed, laminated sheet was next put in a photographic developing equipment where chemical solvents were used to remove the unexposed areas of the photoresist material in step S8. In the next step the developed laminated sheet was put in an etching solution of iron chloride (FeCb), where the non-protected areas of the sheet metal were etched away in step S9. Finally, remaining photoresist material was stripped from the sheet and the steel sheet was thoroughly cleaned in step S10 and S11. The opaque, self-sustaining steel sheet was thus turned into an example of an image display object of the present invention.

The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of the present invention is, however, defined by the appended claims.