Article having optical effects

Abstract

A method and system for forming an article having an optical effect is provided. An original texture is obtained which is digitized using a scanner. The scanner causes a shadow effect on the texture based on the scanning direction. The digitized texture is then edited to define a selected shape. The texture within the selected shape is offset such that its direction is changed. The digitized texture is then engraved by a laser onto the surface of an article. The selected shape is then visually distinct from the other areas of the texture at certain viewing angles caused by the difference in their texture direction. With the present invention, lines or seams between areas of the texture are eliminated.

We claim:  
     
         1 . A method of forming an article having an optical effect, the method comprising the steps of: 
 providing a digital image of a texture;    modifying the texture in a selected portion of the digital image; and    reproducing the digital image on an article, the selected portion having an optical effect different than other portions of the article.    
     
     
         2 . The method as set forth in  claim 1  wherein the modifying includes angularly offsetting the texture in the selected portion of the digital image.  
     
     
         3 . The method as set forth in  claim 2  wherein the angularly offsetting includes changing a direction of the texture in the selected portion.  
     
     
         4 . The method as set forth in  claim 2  wherein the angularly offsetting includes inverting the texture in the selected portion of the digital image.  
     
     
         5 . The method as set forth in  claim 1  wherein the reproducing includes engraving the digital image into the article.  
     
     
         6 . The method as set forth in  claim 1  wherein the providing includes digitizing a textured pattern to generate the digital image of the texture.  
     
     
         7 . The method as set forth in  claim 6  wherein the digitizing includes scanning the textured pattern where the scanning creates a shadow in the textured pattern, the shadow being part of the texture in the digital image.  
     
     
         8 . The method as set forth in  claim 7  wherein the modifying includes changing a direction of both the texture and the shadow in the selected portion.  
     
     
         9 . The method as set forth in  claim 1  wherein the reproducing includes leaning the texture on the article in a first direction and leaning the texture within the selected portion in a second direction.  
     
     
         10 . The method as set forth in  claim 1  wherein the modifying includes changing a size of the texture in the selected portion of the digital image.  
     
     
         11 . The method as set forth in  claim 1  wherein the digital image of the texture includes a grey scale value, the modifying including changing the grey scale value of the texture within the selected portion.  
     
     
         12 . An article having an optical effect comprising: 
 an engraved surface in the article, the engraved surface having a textured grain; and    a shape defined in the engraved surface where the textured grain within the shape is different that the textured grain on other portions of the engraved surface, the shape being visually distinguishable in the engraved surface at selected viewing angles.    
     
     
         13 . The article as set forth in  claim 12  wherein the textured grain within the shape is angularly offset from the textured grain of the engraved surface.  
     
     
         14 . The article as set forth in  claim 13  wherein the textured grain within the shape is in an opposite direction than the textured grain outside the shape such that when the article is viewed from a first angle, the textured grain within the shape appears shadowed while the textured grain outside the shape appears light, and when viewed at a second angle opposite from the first angle, the textured grain within the shape appears light while the textured grain outside the shape appears shadowed.  
     
     
         15 . The article as set forth in  claim 12  wherein the engraved surface is formed by a laser.  
     
     
         16 . The article as set forth in  claim 12  wherein the textured grain is leaning in a first direction creating a first shadow effect and the textured grain within the shape is leaning in a second direction different than the first direction creating a second shadow effect different that the first shadow effect.  
     
     
         17 . The article as set forth in  claim 12  wherein the textured grain within the shape is different in size from the textured grain of the engraved surface.  
     
     
         18 . The article as set forth in  claim 12  wherein the textured grain within the shape includes a different texture than the textured grain of the engraved surface.  
     
     
         19 . A system for forming a latent image on a material comprising: 
 a scanner for digitizing a stipple pattern to obtain a digital stipple pattern;    an image processor for defining an area in the digital stipple pattern by modifying properties of the stipple pattern within the area; and    a laser for engraving the digital stipple pattern on a material where the area exhibits a different optical effect that other portions of the material.    
     
     
         20 . The system as set forth in  claim 19  wherein the stipple pattern includes a grain and the laser engraves the digital stipple pattern by leaning the grain in a first direction and leaning the grain within the defined area in a second direction different from the first direction based on the modified properties of the stipple pattern.  
     
     
         21 . The system as set forth in  claim 19  wherein the scanner includes a means for creating a shadow in the stipple pattern, the shadow being part of the digital stipple pattern.