Patent ID: 6282396
Filing Date: 2001-08-28
Classification: G03G

Abstract:
A method of forming a color image on a recording sheet, comprising the steps of:forming more than one color image positional deviation detecting mark having a common pattern along a common axis, comprising,including on a conveying belt a first line of a first detecting mark in a main scanning direction by operating a first electrophotographic processing section disposed at a first position along said conveying belt, and including a second line of the first detecting mark on said conveying belt positioned at an inclined angle with respect to said first line,including a second detecting mark on said conveying belt by operating a second electrophotographic processing section disposed at a second position along said common axis, said second detecting mark also including a first line and a second line at an inclined angle with respect to said first line; anddetecting said first line and said second line of said first detecting mark and detecting said first line and said second line of said second detecting mark with a single detecting device having a light source, a slit, and a light accepting element, and determining a positional deviation, in the main scanning direction and a subscanning direction, of images formed on said recording sheet by said first electrophotographic processing section and said second electrophotographic processing section based on a conveying speed of said conveying belt, a timing of an interval from when said single detecting device detects said first line and said second line of said first detecting mark, and a timing of an interval from when said single detecting device detects said first line and said second line of said second detecting mark.