| 摘要 |
PROBLEM TO BE SOLVED: To correct 'integration cavity effect' which makes the measurement of light intensity of an image inaccurate by giving an initial parameter of light quantity, etc., which is returned by an internal cavity, calculating true reflectivity by acquiring measurement reflectivity of document, etc., and generating a correction signal. SOLUTION: The quantity f1 to fn of each light source which is complemented by an internal cavity and returned to an image surface and initial parameters of distribution function g1 (x) to gn (x) of returning light are provided (102). Light quantity Mc (x) which is reflected from document and passes through a filter of a corresponding wavelength is measured (106) and converted into a measurement optical signal. A space mean signal (Mc ) of a measuring beam is decided from a corresponding signal Mc (x) (108) and converted into a mean measuring optical signal. The value of a normalization constant Kc is given (114) and converted into a normalization signal. True reflectivity dc (x) is obtained from the document dc (x) based on the measuring optical signal, the mean measuring optical signal and the normalization signal (116) and a correction signal that represents true reflectivity is created. |
