Oliff & Berridge, PLC
Optical measuring method, optical measuring apparatus and image forming apparatus
 A specific reflection area 42 on a paper surface 37a is irradiated with light from a light source 41 via nor not via a lens 43. A photoelectric conversion element 44 is placed on a focal surface in the rearward of the lens 43 and out of the light reflected (including scattering light and diffusion light) from the reflection area 42 on the paper surface 37a, only the whole light reflected within a predetermined angular range is received by the photoelectric conversion element 44 via the lens 43. The density of the image formed on the paper surface 37a is measured from the light reception output. When the paper surface 37a is irradiated with light from the light source 41 via the lens 43, the light source 41 is placed backward from the focal surface 43b in the rearward of the lens 43. 
Fuji Xerox Co., Ltd.
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Hisao Yoshihiko Seigo Hiroyuki
Ito Sakai Makida Hotta