Patent ID: 8203769
Filing Date: 2012-06-19
Classification: G01J,H04N

Abstract:
1. A system for providing color analysis of a toner image on an image bearing surface with a spectrophotometer, the system comprising: an illuminator positioned adjacent to the image bearing surface, the illuminator being configured to emit a light beam at the toner image on the image bearing surface; a linear sensor positioned adjacent to the image bearing surface, the linear sensor being configured to receive the light reflecting off the toner image on the image bearing surface; a gradient index lens placed in an optical path of the light beams reflecting off the image bearing surface, the gradient index lens positioned in between the image bearing surface and a linear variable filter, wherein the linear variable filter is an optical filter having a bandpass coating and a property of the bandpass coating being varied across the length of the linear variable filter so as to shift the center wavelength of the linear variable filter linearly across the length of the linear variable filter; and the linear variable filter placed in the optical path of the light beams reflecting off the image bearing surface, the linear variable filter positioned between the linear sensor and the gradient index lens, wherein the system is devoid of a collimating lens positioned in between the gradient index lens and the linear variable filter, and the linear variable filter and the linear sensor are spaced apart by a gap, wherein the gap between the linear variable filter and the linear sensor is selected so as to maintain the effect of effectively broadening the nominal bandpass characteristics of the linear variable filter whereby a residual error induced by the gap is acceptable to an image quality of the system.