1. Field of the Invention
The invention relates to the field of quality control of finished painted surfaces and in particular to inspection and evaluation of the quality of a painted surface, such as a painted automobile surface.
2. Description of Prior Art
The purchasing decision made with respect to a private automobile is typically heavily influenced by the aesthetic appearance of the automobile. Among the factors that constitute the aesthetic appearance of an automobile is the finished quality of the painted surface. The colors, lusters and finishes that are popular depend in part on fashion, but a deep lustrous finish having a liquid or wet deep mirror-like appearance is generally thought attractive and desirable by the purchaser.
In the prior art, a panel of persons representing a random sample of purchasers views and subjectively evaluates the quality of the painted surface. The panel rates the quality of the paint finish based on several criteria as set forth in a questionnaire. Scores from the panel are then averaged to obtain an average evaluation of the quality of the painted surface. The prior process of using human panels for finish evaluation is extremely time consuming and expensive. At best, such evaluation can only be done periodically. There is also a statistical variation among the panels since truly random samples of human subjects cannot always be practically obtained.
Although the prior art has devised various types of apparatus by which various aspects of a painted surface can be measured, such as a distinctness of image (DOI) meter or a gloss meter, readings from neither one of these prior art apparatus correlates well with the subjective judgments of human panels evaluating the same painted surface.
Therefore, an apparatus and methodology is needed to replace the current paint finish evaluation technique, of periodically using a statistically random group of purchasers or potential purchasers to evaluate quality of the painted finish surface.