When improving the marketability of an industrial product, the exterior design is as important as the basic performance and mechanism of the product. Color is a significant part of the exterior design. In addition, it is a usual practice to coat industrial products for the purpose of protection or improving appearance. Therefore, it is a designer's task to determine the paint color in consideration of functions and characteristics of the industrial product, the customer's request etc.
Clients (such as a manufacturer's designers) make diverse demands regarding the color textures of industrial products. Moreover, clients often make abstract requests for product colors, such as “metallic, translucent, and solid-hard texture”. Paint company designers select paint colors based on their knowledge and experience on the demands of the client. However, such abstract requests can be interpreted differently by different designers. Therefore, color texture requests from a manufacturer's designers are often misunderstood by the paint company designers who actually design the paint colors. This has causes difficulty during the design of paint colors of industrial products. Note that, in this specification, “texture” denotes an impression of a paint color.
There is a way to define paint colors; specifically, there is a way to objectively specify a paint color, using various color chips, color names, or stimulus values in a color space. However, this method is still incapable of defining the relationship between a paint color and its texture. Moreover, among paint colors, it is difficult to define metallic colors by a simple definition because their appearances vary depending on the observation angle.
“Metallic color” is the general name for paint colors whose appearances vary depending on the observation angle, while the paint colors whose appearances are constant regardless of the observation angle are called “solid colors”. Examples of metallic colors include pearl paint colors containing pearl pigments, such as titanium dioxide-coating mica pigments, which exhibit interference colors; and multicolor or bicolor paint colors containing particular effect pigments that cause the color shift (change in color appearance depending on the observation angle).
Therefore, for example, the manufacturing of cars, which are often painted in metallic colors, requires many industrial steps to match the image of the car company designer with the image of the paint company designer. This consumes much of time during car production.
When a car company designer explains the concept of an exterior color, the designer often uses an image board comprising of magazine clippings and/or photos to help interpretation of the abstract requests. While referring to the image board, the paint company designer finds the best color from color stocks that have been designed or used before, or designs a new color, in order to realize a paint color whose appearance matches that of the explained color image. This process depends on the skill of the paint company designer.
This color selection process to find the paint color that best matches the abstract color image request becomes easier if the paint colors are classified and arranged on a two-dimensional map by texture. Further, such a map containing a plurality of paint colors arranged in a two-dimensional manner is useful to grasp the textures of the paint colors.
For example, Japanese Unexamined Patent Publication No. 1999-211569discloses a method of classifying and arranging metallic paint colors, comprising calculating a hue-tone value of a representative metallic paint color, and classifying and arranging the metallic paint colors on a known hue-tone chart.
Further, Japanese Unexamined Patent Publication No. 2003-279413 discloses a method of quantifying the textures, such as metallic appearance or clearness, of metallic paint colors, based on evaluation values obtained from colorimetric values of the paint colors by using a specific function.
Patent Document 1: Japanese Unexamined Patent Publication No. 1999-211569
Patent Document 2: Japanese Unexamined Patent Publication No. 2003-279413