COLOR MEASURING DEVICE HAVING INTERCHANGEABLE OPTICAL GEOMETRIES
 Inventors: Thomas J. Keane; Richard A. Cook,
both of Gaithersburg,, Md.
 Assignee: BYK-Gardner USA, Division of
Allans. Columbia, Md.
 Appl. No.: 512,630
 Filed: Aug. 8, 1995
Related U.S. Application Data
 Continuation-in-part of Set No. 329,280, Oct. 26, 1994, abandoned.
 Int Cl.6 G01J 3/51; G01N 21/47;
 U.S. Cl 356/73; 356/402; 356/445;
356/446  Field of Search 356/73, 402, 445.
 References Cited
U.S. PATENT DOCUMENTS
4,753430 6/1988 Knight et al 356/73
4,916,309 4/1990 Keane 250/227.29
4,995,727 2/1991 Kawagoe et al 3567402
There is provided a high precision device for measuring the color of non-self-luminous or self-luminous objects having interchangeable optical geometries for conversion from one optical geometry to another. The device interchanges a plurality of modules, each having at least one optical geometry for directing illumination from an illumination source and for collecting sample light reflected from a measured object or sample. Such optical geometries include a 45/0 geometry, sphere geometry, specular included geometry, and specular excluded geometry. Each module is removably attached to the device when measurement of the color of the sample is desired and may be separated from the device when measurement of the color of the sample is not desired. Also, each module may include removable filters for absorbing certain types of light, such as ultraviolet visible light, and blocking elements to determine the source of any reference signal. The device may further include a sensing system that automatically determines which module has been installed and to appropriately configure the device.
17 Claims, 9 Drawing Sheets