Spectrophotometer for color printer color control with displacement insensitive optics

An improved spectrophotometer for non-contact measuring of the colors of colored target areas, especially, test patches on moving printed test sheets in an unrestrained normal output path of a color printer, which test patches may be sequentially angularly illuminated with multiple different colors, with a photosensor providing electrical signals in response, the spectrophotometer having a lens system for transmitting that reflected illumination from the test patch to the photosensor with a lens magnification ratio of approximately one to one. The exemplary spectrophotometer provides noncontact color measurements of moving color target areas variably displaced therefrom within normal paper path baffle spacings, with a displacement insensitivity of at least 6 millimeters about a nominal target to spectrophotometer separation.