MXPA01003463A - Lithophane-like article and method of manufacture - Google Patents

Abstract

A lithophane-like article and a method of forming such an article, for example formed of plastics, confectionery product, soap, wax or liquid, by determining the intensity of different points of an original image (1), and forming the article with a thickness at each point of the article related to the intensity of the corresponding point of the original image (1). Preferable, the article is formed by forming a mould, and moulding the article.

Description

ARTICLE TYPE LITHOPHANE AND MANUFACTURING METHOD Description of the Invention In the late nineteenth and early twentieth centuries, porcelain lithophanes were formed. These objects were pieces of porcelain that were formed with sections of various thicknesses. The porcelain was cooked at a very high temperature, resulting in the porcelain becoming translucent. Lighting with light through the porcelain from behind, as a result of the different thicknesses of the porcelain and therefore the different transmission of light through the porcelain, an image is seen. In particular, the thicker areas of the porcelain are less transmitting of light than the thinner areas, and thus appear darker. At the beginning of the twentieth century, the lithophanes were made by hand carving wax with the relief corresponding to the areas of different brightness of the desired image. These wax models were used to form a mold that could be used to mold ceramics to form lithophane. Such lithophanes were used as window hangings, fire defenses, kettle heaters and lamps. Around the 1930s, there was no more interest in lithophanes, and now they are rarely seen. The present invention relates to an article that Ref: 128473 has different thicknesses corresponding to the different intensities of an image, and to a method for forming such an article, the resulting article has an appearance similar to a porcelain lithophane. According to a first aspect of the present invention, a method for forming an article comprises the steps of: determining the relative intensity at different points of an image; and forming the article with different thicknesses corresponding to the different intensities of the original image of a translucent material. According to the present invention, it is possible to replicate a desired image, for example a photograph or computer generated image, in an article in such a way that the image can be observed with adequate illumination. This is possible by virtue of the step of determining the relative intensity of different points of the original image and the automatic use thereof to form the final article with a variable thickness corresponding to the relative intensities. This differs from the lithophanes that were generated as works of art in their own right. It is preferred that the determination of the relative intensity of the different points of the image is obtained by recording the image, for example in a computer. In this case, the original image could be divided into a number of pictorial elements, and a value of intensity for each determined element. The intensity values are then stored preferably in memory for subsequent use in the formation of the article. In this way, the original image can be recreated exactly in the article. By storing the intensity values in a memory, it is possible to process the values, for example to normalize them, or to vary them for different materials. It is also possible to enlarge or reduce the image, or edit the image, for example to remove parts of the image or combine images. It is preferred that the step of forming the article comprises the step of forming a mold, and molding the article in the mold. By molding the article, for example by injection molding techniques, mass reproduction is possible. This allows the production of large volumes of product at a low cost, and. this in turn increases the number of uses for the article. Preferably the step to form the mold is carried out by means of a numerically controlled engraving machine, such as a numerically controlled engraving machine of three high speed axes. This can be loaded with the relative intensity values of the desired mold, and can cut any desired number of molds. If an article that is not flat is going to be produced, a numerically controlled engraving machine with four or five axes may be needed. Alternatively, the mold could be formed by a laser cutting machine, by sparking with erosion in which a spark erosion electrode having a relief corresponding to the finished article is formed and used to form the mold, or by stereo lithography or other techniques The use of these methods to form the mold is especially suited to a method in which the data representing the relative intensity of the pictorial elements are kept in a digital memory. In this case, the data can be used directly to define, for example, cutting path tools or stereo lithography. This allows the rapid, reproducible and accurate formation of molds to be used in the production of the finished articles. Accuracy allows more detail to be seen in finished items. The mold is preferably formed of metal. This allows the materials to be molded, which are heated to a high temperature to melt the material before it cools to harden. Such a mold could also have a long life to allow repeated molding. Alternatively, the mold could be a flexible mold, for example formed of rubber or polyene. This is especially suitable when the article is made of a fragile material, since it allows the article to be easily removed from the mold, for example by flaking the mold, without damaging the article. It is preferred that a number of molds be formed from a block mold, to allow a greater number of articles to be molded simultaneously. In an alternative example of the present invention, the article is formed by machining or otherwise forming the article directly from a translucent material based on the relative intensity determined so that the article has a relief, such that the thickness corresponds to the different intensities of the desired image. This method of forming articles does not allow the same economies of scale and mass reproduction associated with the molding, but is capable of producing limited quantities of items having a specific design. For example, a person image can be obtained from a digital camera or from a registered photograph, and machined in an article. This will be difficult to replicate, and can be used as well as a security or identification device. The article could be formed by a number of methods, including those described above for the formation of a mold, including engraving by a numerically controlled engraving machine, by laser cutting, sparking or stereo lithography. In a further example, the determined relative intensity data is used to form a die, punch or die. The die, punch or die, as well as with the mold, could be formed by means of machining, such as by means of a numerically controlled engraving machine, by laser cutting, sparking or stereo lithography. To form the article, the die, punch or matrix exerts pressure on the surface of the material from which the article is to be formed, and leaves an impression on the material, giving the desired thickness variation for the article. Depending on the material used to form the article, the punch, die or die could be heated before pressure is exerted on the material. These techniques are particularly suitable for the. formation of articles in which a molding step is difficult in the context of the normal production process. A material that is especially suitable for stamping is the chewing gum that is usually formed into strips that are cut to size. The embossing of a strip of chewing gum can be linked to the cut of the strip to the required size. Especially when the article is formed in a strip, the punch, die or die could be provided on a roll. Preferred materials from which the article could be formed include plastics, confectionery products including chewing gum, candy and chocolate, wax, soap and liquids. A particularly preferred material is plastic. Such an article is advantageous over a porcelain lithophane, in which it is significantly cheaper and easier to manufacture, does not require firing at a high temperature and is less susceptible to damage. In addition, by selecting a suitable material, it is possible to see the image clearly when the article is illuminated from the back with a light source of a particular type or intensity. In the case of liquid, the liquid could remain in the mold to maintain the different thicknesses. According to an alternative example of the present application, a plastic article having different thicknesses in different positions is provided, which corresponds to the relative intensity of an image, in which the plastic article transmits or emits light with an intensity which corresponds to the thickness of the material. The material from which the plastic articles are formed should be transparent or translucent, for example they could be made of polystyrene, polypropylene, styluolux, ABS or acrylic, or an expoxy resin, polystyrene or polyurethane. The plastic material is preferably filled with a filler material such as kaolin, gypsum or other filters to give the desired effect. The use of plastics is preferred since this is cheap, can easily be formed to the desired shape, for example, by heating to make the material moldable and cooling to harden, and is resilient, making it less likely to break than porcelain. Plastic materials could also be used for a wide range of products to be used in a large number and variety of environments. Alternative materials from which the article could be formed include confectionery, wax, soap and liquid. When confectionery products are used, for example, chocolate, candy or chewing gum, the finished articles can be eaten. Since many confectionery products are formed to give the desirable appearance, little if any additional cost is required to form the product in an article according to the present invention, but the resulting article has a very attractive appearance, increasing its value. When the article is formed from a liquid, it is preferred that the article comprises a container formed of substantially transparent material, in which the cross-sectional area between opposite walls corresponds to the relative intensity of the image, and the liquid provided in the container. The container could be in the shape of a bottle. The liquid could be a beverage or detergent or cosmetic, such as shampoo. To give the desired effect, the liquid should preferably be of uniform density and transmission, and should be translucent. The material from which the article is formed could include luminous particles or could be covered at the back by a luminous layer. In this case, the luminescent particles emit light, and therefore it may be possible to see the image without light from a separate source that shines through the article. When luminescent particles are included, the lighter parts of the image could correspond to the thicker parts of the article and the darker parts to the thinner parts since, in this case, in the thicker regions there will be a greater amount of particles bright, and therefore there will be a brighter section. The article could be colored. In this case, the article could also be colored with a single color to give a total hue, or there could be different colors in different parts of the article to give parts of different color. When the color is a single color, this could be obtained by including pigment in the material used for molding. Alternatively, a colored layer could be formed on a surface of the article. One surface of the article, for example the back surface, will usually be flat, and therefore a colored layer can easily be formed on this surface, for example by transfer or sublimation printing, or by an ink jet or silk screen printing technique. This will act as a filter to the passage of light through the article. Alternatively, a separate layer could be provided with the appropriate colors, which is provided on the front or back of the article. This allows the color to be formed separately. The article could be formed from a material sensitive to heat. In this case, the image could only be seen when the article is heated. For example, if the article is formed inside a lamp shade, it could be heated by the lamp to become translucent. The article according to the present invention can be used for a number of purposes, including character promotions, key rings, inserts that are provided in cereal packages, light lamp displays, plates, cups, toys, paints, etc. When the article is made of an edible material, such as chocolate or candy, the item could be sold as a new food product. A candle can be formed when the item is made of wax. Through the use of appropriate processing techniques, the article could be a 'non-flat or three-dimensional article. It is also possible to produce a stereoscopic image by having two items side by side that have substantially the same image, but from a slightly different perspective, each of the images is viewed by a different eye of the viewer. In an alternative example, both surfaces of the article include relief. In this case, the total thickness of the material at any point corresponds to the relative intensity of the image at that point, however, the article is hollowed on both sides. This gives an article that can be seen from both sides. When the article includes a flat surface, and the relief is provided exclusively on the other surface, the image can only be viewed appropriately on the relief side of the article. When both surfaces of the article include embossment, it is preferred that the article be hollow on both sides, generally in a similar amount. This facilitates the manufacture of the article.

For example, when the article is formed in a mold, the two parts of the mold could be recorded as a mirror image of one another. The article could be formed as a single piece, or it could be formed in two parts that are fixed rear to rear. When the article is formed in two parts and these are fixed rear with back, such fixation could be by means of an adhesive, or could be by a mechanical interconnection or staple. When the article is formed in two parts, it is possible to provide a colored or luminescent layer between the two parts before they are joined together to give the desired color filter or light radiation that is required. Examples of the present invention will be described in accordance with the accompanying drawings, in which: Figure 1 shows a schematic view of the system, to form an article; Figure 2 shows a cross section through a mold to form an article; Figure 3 shows a cross section through an alternative example of an article; and, Figure 4 shows a bottle of liquid that includes the features of the present invention.

As shown in Figure 1, an image 1, for example a photograph or painting, is recorded by a recorder 2 ("scanner"), to convert the image 1 into electronic data corresponding to the image 1. the corresponding data the recorded image is entered into a processor 3. Alternatively, the image could initially be generated in electronic form, for example using a graphic package, or it could be loaded from a storage of pre-converted or generated images, for example on a CD-ROM , or downloaded, for example from the Internet. The processor 3 analyzes the data corresponding to the images to determine the relative intensity, i.e. the relative darkness or luminosity, in different points or pixels of the image. This analysis could be achieved using computer-aided design or commercially available computer-aided selection programming elements. This intensity information is provided to a numerically controlled selection machine from the programming element, which is capable of using the intensity data to machine a half 11 of a mold in which the depth of the mold in different positions corresponds to the relative intensities of the original image. In a preferred example, the mold has a greater depth when the corresponding position of the original image has a low intensity (ie when the image is dark), and has a shallower depth when the corresponding position of the original image has a high intensity (ie when the image is clear). The machined mold half 11 and an associated mold half 10 generally have a flat surface, are placed together to form a mold cavity, and the plastic material is injected into the mold cavity. To give the plastic material the required translucent properties, a filler material such as kaolin, gypsum or other filter material is added to the plastics before they are injected into the mold cavity. When the plastic material has hardened, it is removed from the mold. The resulting article will be translucent, and will have a greater thickness in the areas corresponding to the darker areas of the original image than the areas corresponding to the lighter areas of the original image. When light shines through the article from behind, the light is transmitted through the thinner parts of the article easier than through the thicker parts of the article, and therefore the thinner areas appear lighter than the thicker areas. This corresponds in general to the light and dark areas of the original image, and therefore an image corresponding to the original image can be seen. The article could be colored on the back by any suitable printing technique, for example inkjet printing. In this case, the color is easy to apply as it is applied to the flat back surface of the article. The colored layer at the back of the article acts as a color filter that only allows light of selected wavelengths to pass through the layer and consequently through the translucent article, and therefore the light seen through the Article is of certain colors. When the back of the article is substantially completely colored with a single color, the entire image seen through the article will have a color hue, however it is preferred that the back of the article be selectively colored with areas of different color. This allows the light to be transmitted through different parts of the article that are of different colors, which could correspond to the colors of the original image. Alternatively, a colored pigment could be added to the plastic material before it is injected into the mold. In this case, the pigment inside the plastic material will act as a filter that only allows the light of certain wavelengths to be transmitted to form the image seen. It is also possible to add a luminescent pigment to the plastic material used to mold the article by injection. In this case, it is not necessary to use a separate tail light to see the article, since the same item will emit light. In this case, the mold is made in reverse of that described above, with the areas that correspond to the lighter sections of the image that form more deeply than the areas that correspond to the darker areas. In this case, the plastic article molded by the mold will be thicker in the areas that correspond to the lighter areas of the original image, and therefore will have a greater amount of luminescent pigment, and therefore emit more light than the thinner areas that correspond to the darker regions of the original image, which will have less luminescent material and therefore emit less light. An alternative example of an article according to the present invention is shown in cross section in Figure 3. In this example, more than the article that is formed with a flat back surface and a front surface having a relief corresponding to the relative intensity of the different parts of the image, the article is formed with a corresponding relief on both sides. This can be achieved either by forming the two halves of the mold with a relief by image to the corresponding mirror, the relief in each part corresponds to half the relief required for the desired total thickness of the finished product, or recording with a CNC machine. Alternatively, as shown in the example of Figure 3, the article may be formed into two parts, each part having a flat face and a face with relief, each part being made according to any of the methods described herein. In this case, the two parts of the article are fixed together in back-to-back ratio. Due to the variation in thickness of the entire article, there will be a similar light transmission as with a single item having a flat back face. However, it is possible to see the image through the article from either side, whereas when a face is flat, it is difficult to see the image of this flat face. As shown in Figure 3, a colored layer is printed on the flat face of a part of the article. In the complete article, this layer is inserted between the two parts of the article and therefore is not susceptible to damage, for example by wear or scratching. The colored layer could be alternatively or additionally a luminous layer, in this case it might not be necessary to hold the article to a light source when the image is seen. The two parts of the article are then joined by means of a suitable adhesive. As in the first example, it is possible to provide a colored or luminescent layer on one side of the article, or make the article from a plastic material that includes colored or luminescent particles. Injection molded articles according to the present invention, which, due to the manufacturing method can be formed inexpensively and in large numbers, can be used in many different applications, for example, but not limited to, character promotions, rings of key, inserts that are provided in cereal packages, lampshades, plates, cups and paints. It could also be possible to form a plastic article having variable thickness or contour, which corresponds to the relative intensity of an original image by engraving the article directly, for example using a CNC machine, in the same way as described above to form the mold . In this case, it would be simple to make an article, for example it would be possible to convert an image of a person's face into data that refers to the relative intensity of the image, and directly record a plastic article with regions of different thickness that correspond to the different intensities of the image of the face of the person. This could be used as a security device, for example as an identification card, which would be difficult to counterfeit. In an alternative example, a bottle of transparent material is formed in which the width of the bottle varies to correspond to the relative intensity of an image. When the bottle is filled with liquid, the amount of liquid will correspond to the relative intensity of the original image. When the liquid is translucent, this variation in the amount of liquid will give darker and lighter regions. A cross section of the bottle is shown in Figure 4.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (31)

1. RE IVINDICATIONS
2. Having described the invention as above, the content of the following claims is claimed as property: 1. A method for forming an article, characterized in that the method comprises the steps of: determining the relative intensity at different points of an image; forming an article of a translucent material so that the article has a relief, in such a way that the thickness corresponds to the different intensities of the image. A method according to claim 1, characterized in that the article has thicker portions corresponding to the darker regions of the original image, and thinner portions corresponding to the lighter regions of the original image.
3. 3. A method in accordance with the claim

   1 or claim 2, characterized in that the relative intensities of the different points of the original image are determined by recording the image in a computer.
4. 4. A method according to any preceding claim, characterized in that the image is analyzed by dividing it into separate pictorial elements, and determining the intensity of each pictorial element.
5. 5. A method in accordance with the claim

   4, characterized in that a value corresponding to the intensity of each pictorial element is stored in memory.
6. 6. A method in accordance with the claim
7. 5, characterized in that the stored values are used to control a computer-controlled engraving machine to form the article. A method according to any of the preceding claims, characterized in that the step of forming the article includes the step of forming a mold having a relief corresponding to the relative intensity of the points of the original image, and molding the article of a translucent material in the mold to form an article having different thicknesses corresponding to the different intensities of the original image.
8. 8. A method in accordance with the claim

   7, characterized in that the mold is formed of metal.
9. 9. A method according to claim 7 or 8, characterized in that the step of forming the mold is an etching step.
10. A method according to any of claims 1 to 6, characterized in that the step to form the article comprises the step of recording the translucent material.
11. 11. A method according to claim 6, 9 or 10, characterized in that the engraving step is achieved using a numerically controlled engraving machine.
12. 12. A method according to claim 6, 9 or 10, characterized in that the engraving step is achieved using laser engraving.
13. 13. A method according to any of the preceding claims, characterized in that the article is formed of a plastic material.
14. A method according to any of claims 1 to 12, characterized in that the article is formed of a confectionery material, such as candy or chocolate.
15. 15. A method according to any of claims 1 to 12, characterized in that the article is formed of a soap.
16. 16. A method according to any of claims 1 to 12, characterized in that the article is formed of a wax.
17. 17. A method according to any of the preceding claims, characterized in that the material includes luminescent particles.
18. 18. A method according to any of the preceding claims, characterized in that it includes the additional step of providing a luminescent layer on or within the article.
19. 19. A method according to any of the preceding claims, characterized in that the article is formed of a colored material.
20. 20. A method according to any of the preceding claims, characterized in that it includes the additional step of providing a colored layer on or within the article.
21. 21. A method according to any of the preceding claims, characterized in that the article is made of a heat-sensitive material whose light transmission properties vary depending on the temperature of the material.
22. 22. An article formed of a plastic material, characterized in that the article has different thicknesses at different points corresponding to the relative intensity of an image.
23. 23. An article formed of a confectionery product, such as candy or chocolate, characterized in that the article has different thicknesses at different points corresponding to the relative intensity of an image.
24. 24. An article formed of soap, characterized in that the article has different thicknesses at different points corresponding to the relative intensity of an image.
25. 25. An article formed of wax, characterized in that the article has different thicknesses at different points corresponding to the relative intensity of an image.
26. 26. An article, characterized in that it comprises a container that contains a liquid, the container is formed to be of variable width, the width in different points corresponds to the relative intensity of an image.
27. 27. An article according to any of claims 22 to 26, characterized in that the material includes luminescent particles.
28. 28. An article according to any of claims 22 to 27, characterized in that a luminescent layer is provided on or within the article.
29. 29. An article according to any of claims 22 to 28, characterized in that the article is formed of a colored material.
30. 30. An article according to any of claims 22 to 29, characterized in that a colored layer is provided on or within the article.
31. 31. An article according to any of claims 22 to 30, characterized in that the article is made of a sensitive material whose light transmission properties vary depending on the temperature of the material.